As of 2020-08-18, this is work in progress.

Proffesional development timeline

Presented to you in reverse chronological order:

Year 2020

2020-08 Bee vs Wasp - a dataset, and contributions to

Challenge: I am looking to demonstrate my machine learning skills.

Action: Create a reasonably difficult dataset for image classification task : distinguish between a bee and a wasp.

Result: I make my dataset public: Kaggle dataset: bee vs wasp . During the work, I discover a bug in the framework . I create a pull request and my patch is accepted.

2020-08 Win a Kaggle competition

Challenge: It seems that the recruiters do not believe in my data analysis skills. I could demonstrate my machine learning skills by completing a Kaggle challenge. This one is nice because it has over 100k submissions, meaning that it is easy to see if I am winning or not, especially if I decide to not cheat. I figure that in order to get to the top 20%, I need to get a MSE lower than ~16’400. Let’s go.

Action: Download the training data to my local machine. (this helps in the exploration & data cleaning phase). Clean the data; Try a number of methods; when score is better than 16’400, submit.

Result: On a first try (not counting the tutorial) I get to the top 3%, with a score of 13659. See - note, I am listed under my old nickname there, Jurek

Techniques used:

Skills used: Python, pandas, numpy, scikit, xgboost, PyTorch

See this: my progress notes and comments

2020-07 Read through “Understanding the FDTD Method” by John B.Shneider

Challenge: Having my experience of using PZFlex and general concepts of FDTD, I have an idea for an efficient implementation of ultrasonic elastic wave FDTD for a certain problem that I have in mind for the future. However, my maths is a bit rusty. I decide review some papers and books a refresher

Action: Find a number of books on the topic, and decide to start from this one

Result: My maths is refreshed. I start to write my own FDTD stepping engine.

See this: my progress, notes and comments

2020-07 Read-through “Domain Driven Design” by Eric Evans

Challenge: Most scientific research projects include writing a piece of software to run the experiment, to do a simulation, or to provide a demonstration and training material. The bigger the piece, the more clear the need to engineer it in such a way to make it sustainable. In my career so far, I have seen multiple packages become cluttered and unserviceable; some are rewritten from scratch only to face the same outcome. It came to a point where during my recent work, I have raised the need for a software architect, but have been denied one on the basis of cost.

Action: I decide to become a software architect myself. I research relevant literature, including TDD. After a few bounces, I land on the classic DDD book by Eric Evans.

Result: This event is in progress

See this: my progress, notes and comments here

2020-06-22 workshop: “From Vague thoughts to clear action”.

Go straight to the Details

2020-06 Became a Certified Associate in Project Management - CAPM

Action : Obtain training in general-purpose project management, with a focus on issues that are relevant for professional science projects.

Result: CAPM certification obtained. I begin to use project management in my daily work and see a notable improvement in work effectiveness.

Skills used: Perseverance, Fast reading, mnemotechnics, learning.

See this: more details on my CAPM ,or the Official certification badge

2020-06 PMBOK document templates

Challenge: PMI project management system postulates tailoring the project management process to the needs of the project, but there are still many common elements that can benefit from having a hyperlinked template.

Action: Develop a set of templates for project management, in markdown. Announce the resource in Rands Leadership.

Result: I see improvements in the efficacy of the projects I do. No external impact noted as of 2020-07.

Skills used: Technical writing, git, markdown

See this: PMBOK document templates github repository

Challenge: My two favourite markdown editors (Typora, Obsidian) use different styles for intra-project hyperlinks. I’d like to interoperate both to maximise writing productivity.

Action: Write a robust style converter in python.

Result: pip install typobs package link style converter. Open-sourced.

Skills used: requirements analysis, software engineering, python.

See this: typobs Github repository

2020-04 Healthy body homes a healthy soul

Challenge: As the pandemic hits the UK, lockdown severely restricts the opportunity for social, physical activities.

Action: Designate an area of the house as a gym. Equip with cardio and strength training equipment.

Result: I feel stronger and healthier than ever. expect more details soon.

Skills used: perseverance, initiative, fast reading, meditation, learning

2020-04 I adopt a new pen name: George Rey

Challenge: my Polish name, Dr Jerzy Dziewierz, is impossible to say correctly in the English speaking world. It is also difficult to say in polish. Even my teacher of polish literature in Poland had a problem saying it correctly. I am worried that this creates a multitude of soft issues for me.

Action: I adopt a pen name. George is the literal translation of Jerzy; this connection has a well documented in linguistics anthropology. Rey is my family name from mother’s side; it is a big polish family, and it happens to be easy to say.

Result: This event is in progress

Skills used: research, law & legal

2020-03 3DCrowd and HackThePandemic

Challenge: Global pandemic. Someone needs to do something. This someone is me.

Action: Volunteer to the nationwide effort to bring PPE to the front line and key workers

Result: 145’000+ face shields delivered to the front line workers, £114’000 raised in donations.

Skills used: 3D printing, HTML and LAMP, organisation and scheduling, negotiation, networking, initiative

See this: 3D Crowd website, #HackThePandemic website - do not confuse with another site named the same way.

2020 Cross-team collaboration (2 instances)

Challenge 1: a team in another section of the company can use my expertise in an undisclosed project in mechanical engineering.

Challenge 2: a team in another section of the company can use my expertise in an undisclosed project in electronic signal conditioning engineering.

Action: Provide expert opinion, conduct computations, generate written recommendations.

Result: Strategic direction of the company section updated. Time saved. As a recognition of the input, I am being listed as a co-author on the patent application.

Skills used: Technical communication, technical writing, python, electronic engineering, signal conditioning, mechanical engineering, Solidworks, expertise in ultrasound

Year 2019

2019-11 3D printing rescues presentation of a prototype to the client

Challenge: a prototype device, about to be demonstrated to a prospective client, cracks and breaks down.

Action: I quickly take the moulded part design file and redesign it for manufacturability with the local 3D printer. I stay at the office late to monitor the quality and safety of the printout. I help to integrate the replacement part into the prototype in the morning. I provide advice on how to avoid weak spots in the final design.

Result: The presentation is a success, and the company earns a contract for a run of the devices for a high-profile bespoke virtual reality integrator. The original moulded design is redeveloped to avoid the weak spot.

Skills used: Mechanical engineering, 3D printing, technical communication

2019-10 International Ultrasound Symposium, Glasgow

Notable event: I attend the 2009 IUS in Glasgow. My role this time is to scout for emerging technologies and research groups relevant to the business at hand. I also seize an opportunity to promote Ultraleap to the new PhD and EngD cohort. See the event official page. No publications this time around.

Skills used: networking, international collaboration, research, presentation.

2019-09 LEVITATE project meeting, Bayreuth, Germany

Notable event: As a member of the EU-funded LEVITATE project I am invited to the project meeting. I deliver a presentation on handybeam. Participating organisations : the University of Glasgow, University of Sussex, Universität Bayreuth, Chalmers University of Technology, Ultrahaptics. This project received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no 737087.

Skills used: networking, international collaboration, presentation, educational material preparation

2019-06-25 Delivered the RCNDE EngD Course in ultrasound

Action: I deliver two lectures and a workshop to the 2019 RCNDE EngD student cohort.

Lecture 1: “Piezoelectric Ceramic Composite Transducer technology”.

Lecture 2: “Array transducer design guidelines”.

Workshop: “Design of ultrasonic phased array” which demonstrates the entire process of designing a piezoelectric composite structure, and a linear phased array, to match or exceed inspection requirements-driven specifications.

The hands-on workshop includes training in basic PZFlex FEM for piezocomposite modelling, as well as training in my own, open-source software package “handybeam” for simplified ultrasonic propagation modelling.

Most of the content is copyrighted, but you can get a sneak preview of one of the documents

2019-05 Ultrahaptics changes name to Ultraleap

Notable event: Ultrahaptics joins forces with Leap Motion and becomes Ultraleap

2019-05 HandyBeam is open-sourced

Notable event: My open-source package, HandyBeam is approved for official open-sourcing. See the official git repository here.

2019-03 Contributions to the in-house ultrasonic transducer driver chip

Challenge: A group in the company develops a custom silicon chip to drive many ultrasonic transducers in a cost-effective manner. They observe previously unpredicted current flow that could be dangerous to the chip. I am being asked to advise.

Action: I conduct a detailed analysis of the source of the problem. This involves an experimental evaluation of the ultrasonic transducers in question. I discover the source of the unpredicted behaviour. I write a detailed report on the findings and prepare an educational presentation. I deliver the presentation to the team, which includes several options for correcting the problem.

Result: One of the proposed options is selected, and the chip passes the validation gate, potentially saving the company money on a failed silicon wafer run.

Skills used: Lab work, Experimental set-up, hypothesis generation, experimental evaluation, technical writing, technical communication, electronics, signal conditioning, micromechanics, ultrasound.

2019-02 Probabilistic programming and PyMC3 for haptic sensation quality stratification

Challenge: Our device can produce a variety of sensations. These sensations can be qualitatively described, but is there a quantitative way of ranking them by, e.g. “strength” or “pleasure”? Moreover, when designing a new sensation, is there a way of knowing how it will rank against existing sensations without re-running a study on the entire population?

Action: I read books on Bayesian modelling: this one and this one; I study the Glicko algorithm; I take the existing in-company experimental data; I adapt the Glicko algorithm to Bayesian form; I develop a variation of Glicko algorithm that better reflects the available experimental data. I discover a set of anomalies in the existing data that previous approaches did not discover; I curate the data and recover useable information.

Result: I give an internal presentation on the work conducted. The new method enables to quickly not only rank new sensations but also assign a numerical quality value to any new haptic sensation developed by the experience artists.

Skills used: initiative, research, mathematics, learning, Bayesian, probability, python, PyMC3, technical communication, machine learning, presentation

2019-01 Bristol UKAN/RCNDE Workshop in Arrays

Notable event: I attend the UKAN/RCNDE workshop and in phased arrays. See the archived programme.

2019 Haptic localisation calibration device

Challenge: The alignment between optical tracking and haptic sensation has never been characterised quantitatively. This is because there has never been a tool to do that. The approach so far was “it feels OK”.

Action: Recognise the need for quantitative data. Propose and document a bespoke measurement device.

Result: The need for the team is recognising the need for calibration, but the work required is postponed until resources become available.

Skills used: Initiative, technical writing, persuasion, research, expertise in ultrasound.

2019 Novel, radical high power ultrasonic transducer

Challenge: The haptic projector would benefit from higher output power. Yet, the piezoelectric transducer technology is fundamentally maxed out due to thermal limits of the piezo material.

Action: Develop a concept of a radically novel concept of ultrasonic emitter principle. Review literature for related ideas. Build and demonstrate a prototype. Estimate development costs

Result: Patent application, IP produced

Skills used: Research, technical communication, presentation, expertise in ultrasound, mechanical engineering, electronic engineering, COMSOL simulations, python, plotly

2019 Haptic interaction zone CAD

Challenge: The quality of the haptic experience delivered by the haptic projector varies across space above the projector. I identify a need for visualisation space of ‘acceptable quality’, and a way to design haptic projectors to maximise this space.

Action: I propose, document, and implement in software, a range of quantitative metrics for ultrasonic beam and focal point quality estimation. I extend my handybeam package to compute the focal point quality metrics across space for given haptic projector design. I visualise the results and discuss the results with the team. I introduce new terminology to facilitate discussion.

Result: The cross-team follow-up discussions resulted in a better understanding of the physics package and interaction between the ultrasound output capability and haptic sensation quality, across the company.

Skills used: initiative, literature review, software engineering, presentation, python, plotly

2019 Ultra-low-cost approximate beamforming

Challenge: Some of the available surface beamforming algorithms are too computationally expensive to be used in a real-time, embedded environment.

Action: I propose to develop a range of very simple “transformer” algorithms, that take an existing surface solution and transform it, effectively moving the acoustic field across space. I develop a research program, including risk management. I take on an intern with a mathematics background, train the intern on computer architecture, ultrasound propagation modelling and oversee the work.

Result: The Transformers algorithm is demonstrated and quantitively evaluated to provide acceptable loss quality and extremely low cost of implementation. However, new, faster direct-solution algorithms emerge that make “transformers” not necessary except for most compute-starved products.

Skills used: research, research project management, mentoring, presentation, technical communication, technical writing, code review.

2019 Surface beamforming for haptic textures

Challenge: Innovation is needed in haptic projector technology to enable the delivery of dynamic haptic textures to the user’s hand, instead of a single or a few ‘points’ possible so far.

**Action: ** I develop a research program, including risk management. I take on an intern with a mathematics background, train the intern on computer architecture, ultrasound propagation modelling and oversee the work. I review the code written and guide the experimental evaluation. I review the final report. I interact with the project sponsor.

**Result: ** A selection of algorithms known from the literature have been implemented, and experimentally demonstrated. Technical limitations have been enumerated. Results presented to the company’s leadership. A roadmap to commercialisation of the technology has been established.

Skills used: research project management, mentoring, presentation, persuasion, conflict resolution, preparation of educational material, software engineering, code review, technical writing. More details…

2019 low-cost 3DOF scanner with ultrasound measurement head

Challenge: The company has a high precision 6DOF robot for ultrasonic field scanning. However, it is not available to research due to high occupancy with commercial projects.

Action: I propose to repurpose a cheap 3D printer frame into a 3DOF ultrasound field scanner. I calculate that the accuracy will be enough for our needs, producing a significant cost saving. I procure the equipment, design and manufacture custom 3D printed parts, I assemble and deploy the system. I write the custom control interface software. I write documentation and train other team members in using the new equipment.

Result: Two instances of the 3DOF scanner enable acceleration of range of research projects, parallel in the UK office and USA office. Money saved due to not over-specifying the accuracy required. Researchers from across the company get trained and benefit from using the new instrument.

Skills used: Mechanical engineering, budgeting, persuasion, technical communication, instrument interfacing, automation, python, plotly, presentation, educational material preparation.

2019 Upgrade a legacy CAD software to a python research package

Challenge: Some of the company’s crucial, valuable IP is locked in a hastily developed, poorly designed C++ tool. This obstructs further development and research.

Action: I redevelop the IP into a pythonic representation, and reverse engineer it to build readable documentation. I create a test suite to verify correctness and equivalence with the old implementation. Additionally, I take a co-lead role to guide an intern that works on one specific aspect of the new CAD package.

Result: The previously-locked IP becomes available for research and further improvements and alternatives study; improved data visualisation, improved maintainability, improved documentation, new team member onboarding, and more.

Skills used: C++, python, technical writing, perseverance

2019 Develop a company-wide morale-boosting speech

Challenge: I observe a morale and motivation problem among the team.

Action: I engage the highest levels of company leadership to discuss the problem. I develop a series of mini- speeches, arguments, and cultural explainers. I disperse these to the team, sometimes in a way that would make the other person believe that it’s his idea.

Result: Morale of the team noticeably improved, and tone of discussions changed. Over time, a discussion of technical capability for a new, socially responsible product line emerges. The work on a new product begins - product to be released in 2021.

Skills used: Philosophy, communication, initiative

2019 Enhanced phased array imaging through reverberating interfaces

Publication: Marcus Ingram, Jerzy Dziewierz, Anthony Gachagan, Anthony Mulholland, Alison Nordon, Martin Hegarty “ Enhanced phased array imaging through reverberating interfaces”

Abstract: A key challenge to achieve non-invasive industrial process analysis is the transmission of information through the vessel wall. Typical non-invasive technologies, such as Raman spectroscopy, require an optically transparent ‘window’ into the process to acquire the process data. In this work, ultrasonic phased arrays were used to image a dynamic process through planar steel vessel walls into a fluid load. Due to the acoustic impedance mismatch at the steel-fluid interface, only a small fraction of the excitation energy comes back to the receiver in the form of useful echoes from the process. Also, the ultrasonic energy that is not transmitted across the steel-fluid interface reverberates within the vessel wall, masking signals that are reflected from within the process. Here, the ultrasonic array was deployed using Full Matrix Capture (FMC) followed by the Total Focusing Method (TFM) that focusses the ultrasonic beam at every pixel in the image. However, the TFM algorithm is not spatial resolved, leading to multiples of the reverberations interfering throughout the desired image region. To extract the signals corresponding to the process fluid, a method has been developed called the Reverberation Pattern Gain Correction Method (RP-GCM). Firstly, the algorithm uses ray-tracing to predict the path length of reverberations from the steel-fluid interface. The signals in the FMC data set corresponding to those reverberations are then windowed and a gain filter applied, prior to application of the regular TFM process. The RP-GCM has been applied to a simulated FMC data set, developed in PZFlex (OnScale, USA). Initial results demonstrate the effectiveness of this method in separating the vessel reverberations from the ultrasonic echoes of interest relating to the process.

See also: Full text; Researchgate publication page

2019 Intentional weld defect process: From manufacturing by robotic welding machine to inspection using TFM phased array

Publication: Yashar Javadi, Momchil Vasilev, Jerzy Dziewierz and 5 others under guidance from Anthony Gachagan, “Intentional weld defect process: From manufacturing by robotic welding machine to inspection using TFM phased array”

Abstract: Specimens with intentionally embedded weld defects or flaws can be employed for training, development and research into procedures for mechanical property evaluation and structural integrity assessment. It is critical that the artificial defects are a realistic representation of the flaws produced by welding. Cylindrical holes, which are usually machined after welding, are not realistic enough for our purposes as it is known that they are easier to detect than the naturally occurring imperfections and cracks. Furthermore, it is usually impractical to machine a defect in a location similar to where the real weld defects are found. For example, electro-discharge machining can produce a through hole (cylindrical reflector) which neither represents the weld porosity (spherical voids) nor the weld crack (planar thin voids). In this study, the aim is to embed reflectors inside the weld intentionally, and then locate them using ultrasonic phased array imaging. The specimen is an 8 mm thick 080A15 Bright Drawn Steel plate of length 300 mm. Tungsten rods (ø2.4-3.2 mm & length 20-25 mm) and tungsten carbide balls (ø4 mm) will be used to serve as reflectors simulating defects within the weld itself. This study is aligned to a larger research project investigating multi-layer metal NDE found in many multi-pass welding and wire arc additive manufacturing (WAAM) applications and as such, there is no joint preparation as the first layer is deposited over the plate surface directly and subsequent layers contribute to the specimen build profile, similar to the WAAM samples. A tungsten inert gas welding torch mounted on a KUKA robot is used to deposit four layers for each weld, with our process using nine passes for the first layer, down to six passes for the last layer. During this procedure, the tungsten artificial reflectors are embedded in the weld, between the existing layers. The sample is then inspected by a 10 MHz ultrasonic phased array in direct contact with the sample surface using both conventional and total focusing method (TFM) imaging techniques. A phased array aperture of 32 elements has been used. The phased array controller is FIToolbox (Diagnostic Sonar, UK). Firstly, a focused B-scan has been performed with a range of settings for the transmit focal depth. Secondly, a full-aperture TFM method has been processed. All the reflectors of interest were detected successfully using this combination of B-scan and TFM imaging approaches.

See: This resource, Full text

2019 Ultrasonic Phased Array Inspection of Wire + Arc Additive Manufacture Samples Using Conventional and Total Focusing Method Imaging Approaches

Publication: Yashar Javadi, Charles Macleod, Jerzy Dziewierz, and 8 others under guidance of Stephen Gareth Pierce, “Ultrasonic Phased Array Inspection of Wire + Arc Additive Manufacture Samples Using Conventional and Total Focusing Method Imaging Approaches”

Abstract: In this study, three aluminium samples produced by wire arc additive manufacturing (WAAM) are inspected using ultrasonic phased array technology. Artificial defects are machined using a centre drill, ø3 mm, and electro-discharge machining (EDM), ø0.5-1 mm, in a cylindrical through hole topology. The sample was first inspected by a single element wheel probe mounted on a KUKA robot in order to investigate the feasibility of using a conventional ultrasonic transducer approach. Unfortunately, the wheel probe was found to be unsuitable for scanning of the WAAM specimens and ultrasonic phased arrays were employed next. The setup included 5 MHz and 10 MHz arrays (128 elements) in direct contact with the sample surface using both conventional and total focused matrix (TFM) imaging techniques. Using FIToolbox (Diagnostic Sonar, UK) as the controller, a phased array aperture of 32 elements has been used to perform a focussed B-scan with a range of settings for the transmit focal depth. All the reflectors (including those located near the WAAM top surface) were successfully detected by a combination of conventional phased array and TFM, using a range of settings and setups including bottom surface inspection, application through a Plexiglas wedge and variation of the scanning frequency.

See: This resource,

2019 Engineering of acetaminophen particle attributes using a wet milling crystallisation platform

Contributions: Ahmed, Bilal and Brown, Cameron J. and McGlone, Thomas and Bowering, Deborah L. and Sefcik, Jan and Florence, Alastair J. (2019) Engineering of acetaminophen particle attributes using a wet milling crystallisation platform. International Journal of Pharmaceutics, 554. pp. 201-211. ISSN 0378-5173

Abstract: Wet milling coupled with crystallisation has considerable potential to deliver enhanced control over particle attributes. The effect of process conditions and wet mill configuration on particle size, shape and surface energy has been investigated on acetaminophen using a seeded cooling crystallisation coupled with a wet mill unit generating size controlled acetaminophen crystals through an interchangeable rotor-tooth configuration. The integrated wet milling crystallisation platform incorporates inline focused beam reflectance measurement (FBRM) and particle vision measurement (PVM) for in-depth understanding of particle behaviour under high-shear conditions. We used a recently developed computational tool for converting chord length distribution (CLD) from FBRM to particle size distribution (PSD) to obtain quantitative insight into the effect of the competing mechanisms of size reduction and growth in a wet milling seeded crystallisation process for acetaminophen. The novelty of our wet milling crystallisation approach is in delivery of consistent surface energies across a range of particle sizes. This highlights the potential to engineer desirable particle attributes through a carefully designed, highly intensified crystallisation process.

Note: I have provided data collection, signal pre-processing, and machine learning platform for this effort.

Year 2018

2018-12 Represent the company in the ICT Vienna 2018 exhibition

Notable event: I attend the ICT 2018 Conference and exhibition, - a 3-day event. I represent an EU-cofunded research project and the company to an international audience, giving a range of demonstrations, and answering questions.

Action: I create a detailed internal report of the observed user interactions with our device.

Result: The report produces an impact on the company. Over time, the findings from the report are incorporated in the device programming, demo design, and customer interaction tactics.

Skills used: Customer care, presentation and technical communications, international travel, careful observation, product refinement

2018-10 Virtual Prototyping of a Catheter Transducer Array for Internal Hepatic Sonoporation

Contributions: as a part of a team, I contribute to this paper, submitted to IEEE IUS 2018

2018-10 Cross-team collaboration

Challenge: A team in another section of the company can use my expertise in an undisclosed project in mechanical system analysis

Action: Provide expert opinion, conduct computations, generate written recommendations.

Result: I act as an internal consultant - this mitigates the need for an external consultant.

Skills used: Technical communication, technical writing, electronic engineering, mechanical engineering, machine learning, expertise in ultrasound

2018-04 Join Ultrahaptics

Notable event: A significant step in a career, I move on from academia to industry.

Challenge: Adapt to the new environment.

Action: Join Bristol Central Speakers (Toastmasters), Join a local hiking group

Result: I am acclimatised in the new city.

Skills used: Networking, initiative

2018 Develop a company-wide, cross-disciplinary language

Challenge: As the company is relatively new and radically innovative, it pulls talent from a variety of fields, including software engineering, machine learning, non-destructive testing, medical ultrasound, and more. Domain jargon and terminology collisions impede the collaboration. Meetings are repeatedly spent going in circles because people do not understand each other.

Action: I recognise the need for action and take the initiative. I find an old glossary, started, but underdeveloped, in the company’s wiki system. I take ownership for developing and nurturing it. I incrementally add new terms and refine existing terms. I resolve naming conflicts and negotiate the use of new words for old problems. I explain to everyone that we need a common language to facilitate quicker, more correct collaboration.

Result: A common language develops, making intra-team and cross-team collaboration more time-efficient and less stressful. In the following months, multiple kudos are given out to a range of people for sharing their knowledge.

Skills used: Technical speaking, Technical writing, creating and using visual aids, meeting facilitation, negotiation, persuasion, presentation, strategic thinking, initiative

2018 Submit multiple project proposals and invention disclosures

Notable event: Change of environment from academic to industrial results in a spur of creativity.

Skills used: Initiative, technical writing, expertise in ultrasound

2018 Virtual prototyping of a catherer transducer array for internal hepatic sonoporation

Publication: Alexandru Moldovan, Holly Lay, Jerzy Dziewierz, Anthony Gachagan, Sandy Cochran, Virtual prototyping of a catheter transducer array for internal hepatic sonoporation

See also: Researchgate publication page . Full text pending.

2018 Multi-sensor inline measurements of crystal size and shape distributions during high shear wet milling of crystal slurries

Publication: Okpeafoh Stephen Agimelen, Vaclav Svoboda, Jerzy Dziewierz and 10 others, under guidance of Jan Sefcik, “Multi-sensor inline measurements of crystal size and shape distributions during high shear wet milling of crystal slurries”

Abstract: Size and shape distributions are among critical quality attributes of particulate products and their inline measurement is crucial for monitoring and control of particle manufacturing processes. This requires advanced tools that can estimate particle size and shape distributions from multi-sensor data captured in situ across various processing steps. In this work, we study changes in size and shape distributions, as well as number of particles during high shear wet milling, which is increasingly being employed for size reduction in crystalline slurries in pharmaceutical processing. Saturated suspensions of benzoic acid, paracetamol and metformin hydrochloride were used in this study. We employ our recently developed tools for estimating particle aspect ratio and particle size distributions from chord length distribution (CLD) measurements and imaging. We also compare estimated particle size distributions from CLD and imaging with corresponding estimates from offline instruments. The results show that these tools are capable of quantitatively capturing changes in particle sizes and shape during wet milling inline. This is the first time that such a capability has been reported in the literature. The ability to quantitatively monitor particle size and shape distributions in real time will enable development of more realistic and accurate population balance models of wet milling and crystallisation, and aid more efficient control of crystallisation processes.

See also: Researchgate publication page, Full text

2018 Multi-sensor measurements of quantitative particle size and shape information in crystal slurries

Contributions: Ferreira, Carla Sofia and Ahmed, Bilal and Cardona, Javier and Agimelen, Okpeafoh and Sefcik, Jan and Chen, Yi-Chieh (2018) Multi-sensor measurements of quantitative particle size and shape information in crystal slurries. In: 8th World Congress on Particle Technology, 2018-04-22 - 2018-04-26, Orlando World Center Marriott.

Abstract: Particle size and shape are critical quality attributes for active pharmaceutical ingredients (API) as they have direct impact on downstream processing, as well as on the performance behaviour of the finished product. Obtaining a reliable and robust quantitative information of these particle attributes in real-time remains a great challenge across the multiple manufacturing steps and cannot be achieved by just using a single sensor.

Note: I have provided the Experimental framework, mechanical engineering, software engineering, signal pre-processing, and data fusion for this effort.

See: This resource, Full text

2018 Monitoring API crystal breakage in wet milling using inline imaging and chord length distribution measurements

Publication: Ahmed, Bilal and Svoboda, Vaclav and Agimelen, Okpeafoh and Cardona, Javier and Dziewierz, Jerzy and Brown, Cameron and McGlone, Thomas and Cleary, Alison and Tachtatzis, Christos and Michie, Craig and Florence, Alastair J. and Andonovic, Ivan and Mulholland, Anthony and Sefcik, Jan (2018) Monitoring API crystal breakage in wet milling using inline imaging and chord length distribution measurements. In: 8th World Congress on Particle Technology, 2018-04-22 - 2018-04-26, Orlando World Center Marriott.

See: This resource, Full text

2018 Enabling precision manufacturing of active pharmaceutical ingredients : workflow for seeded cooling continuous crystallisations

Contributions: Brown, Cameron J. and McGlone, Thomas and Yerdelen, Stephanie and Srirambhatla, Vijay and Mabbott, Fraser and Gurung, Rajesh and Briuglia, Maria L. and Ahmed, Bilal and Polyzois, Hector and McGinty, John and Perciballi, Francesca and Fysikopoulos, Dimitris and Macfhionnghaile, Pól and Siddique, Humera and Raval, Vishal and Harrington, Tomás S. and Vassileiou, Antony D. and Robertson, Murray and Prasad, Elke and Johnston, Andrea and Johnston, Blair and Nordon, Alison and Srai, Jagjit S. and Halbert, Gavin and ter Horst, Joop H. and Price, Chris J. and Rielly, Chris D. and Sefcik, Jan and Florence, Alastair J. (2018) Enabling precision manufacturing of active pharmaceutical ingredients : workflow for seeded cooling continuous crystallisations. Molecular Systems Design & Engineering, 2018 (3). pp. 518-549. ISSN 2058-9689

Abstract: Continuous manufacturing is widely used for the production of commodity products. Currently, it is attracting increasing interest from pharmaceutical industry and regulatory agencies as a means to provide a consistent supply of medicines. Crystallisation is a key operation in the isolation of the majority of pharmaceuticals and has been demonstrated in a continuous manner on a number of compounds using a range of processing technologies and scales. Whilst basic design principles for crystallisations and continuous processes are known, applying these in the context of rapid pharmaceutical process development with the associated constraints of speed to market and limited material availability is challenging. A systematic approach for continuous crystallisation process design is required to avoid the risk that decisions made on one aspect of the process conspire to make a later development step or steps, either for crystallisation or another unit operation, more difficult. In response to this industry challenge, an innovative system-wide approach to decision making has been developed to support rapid, systematic, and efficient continuous seeded cooling crystallisation process design. For continuous crystallisation, the goal is to develop and operate a robust, consistent process with tight control of particle attributes. Here, an innovative systems-based workflow is presented that addresses this challenge. The aim, methodology, key decisions and output at each at stage are defined and a case study is presented demonstrating the successful application of the workflow for the rapid design of processes to produce kilo quantities of product with distinct, specified attributes suited to the pharmaceutical development environment. This work concludes with a vision for future applications of workflows in continuous manufacturing development to achieve rapid performance based design of pharmaceuticals.

Note: I have provided experimental system design, experimental software including user interface, dashboard, and machine learning (temperature profile decoding), to this effort.

See: This resource, Full text

2018 A transdimensional Bayesian approach to ultrasonic travel-time tomography for non-destructive testing

Contributions: Tant, K M M and Galetti, E and Mulholland, A J and Curtis, A and Gachagan, A (2018) A transdimensional Bayesian approach to ultrasonic travel-time tomography for non-destructive testing. Inverse Problems, 34 (9). 095002. ISSN 0266-5611

Abstract: Traditional imaging algorithms within the ultrasonic non-destructive testing community typically assume that the material being inspected is primarily homogeneous, with heterogeneities only at sub-wavelength scales. When the medium is of a more generally heterogeneous nature, this assumption can contribute to the poor detection, sizing and characterisation of any defects. Prior knowledge of the varying velocity fields within the component would allow more accurate imaging of defects, leading to better decisions about how to treat the damaged component. This work endeavours to reconstruct the inhomogeneous velocity fields of random media from simulated ultrasonic phased array data. This is achieved via application of the reversible-jump Markov chain Monte Carlo method: a sampling-based approach within a Bayesian framework. The inverted maps are then used in conjunction with an imaging algorithm to correct for deviations in the wave speed, and the reconstructed flaw images are then used to quantitatively measure the success of this methodology. Using full matrix capture data arising from a finite element simulation of a phased array inspection of a heterogeneous component, a six-fold improvement in flaw location is achieved by taking into account the reconstructed velocity map which exploits almost no a priori knowledge of the material’s internal structure. Receiver operating characteristic curves are then calculated to demonstrate the enhanced probability of detection achieved when the material map is accounted for.

Note: I have provided experimental design, experimental software, data pre-processing, physics of ultrasound consultancy to this effort.

See: This resource, Full text

2018 Image analysis framework with focus evaluation for in situ characterisation of particle size and shape attributes

Contributions: Cardona, Javier and Ferreira, Carla and McGinty, John and Hamilton, Andrew and Agimelen, Okpeafoh S. and Cleary, Alison and Atkinson, Robert and Michie, Craig and Marshall, Stephen and Chen, Yi-Chieh and Sefcik, Jan and Andonovic, Ivan and Tachtatzis, Christos (2018) Image analysis framework with focus evaluation for in situ characterisation of particle size and shape attributes. Chemical Engineering Science, 191. pp. 208-231. ISSN 0009-2509

Abstract: Particle processing industries, such as pharmaceutical, food processing and consumer goods sectors, increasingly require strategies to control and engineer particle attributes. In both traditional batch and continuous processes, particle size and shape need to be effectively monitored through in-line measurements from Process Analytical Technologies. However, obtaining quantitative information from these measurements has proven to be challenging and in-line imaging techniques are primarily used for qualitative purposes. Two key challenges are: (1) the presence of out-of-focus objects and (2) images only represent 2D projections of three-dimensional objects. In this work, a novel framework to process frames from in-line imaging probes incorporates a focus evaluation step in order to extract meaningful quantitative shape and size information through rejection of out-of-focus particles. Furthermore, a model is proposed that simulates the 2D projection of three-dimensional particles onto the focal plane and computes the corresponding size and shape distributions. The framework is quantified and evaluated against standard particles of well-defined size and shape such as polystyrene microspheres and needle-like cuboid silicon particles.

Note: I have provided the original version of the image processing framework, the image processing technology and consulting, MATLAB programming, clustering and statistics generation, domain decomposition, object classification, and more – before Javier took it over and bolted on a GUI on top of it. This GUI was then what was presented to the stakeholders. I have been providing support for theory of image processing, statistics and classification until the end of the project. I understand why would they not list me as a second author for this paper… maybe it’s because I have been a PI on a different project at the time the paper was ready to go.

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2018 The role of in-line image analysis in the transition to continuous manufacturing in the pharmaceutical industry

Contributions: Cardona, Javier and Ferreira, Carla and Svoboda, Vaclav and Ahmed, Bilal and McGinty, John and Agimelen, Okpeafoh S. and Hamilton, Andrew and Cleary, Alison and Atkinson, Robert and Michie, Craig and Marshall, Stephen and Florence, Alastair J. and Chen, Yi-Chieh and Sefcik, Jan and Andonovic, Ivan and Tachtatzis, Christos; Thorvald, Peter and Case, Keith, eds. (2018) The role of in-line image analysis in the transition to continuous manufacturing in the pharmaceutical industry. In: Advances in manufacturing technology XXXII. IOS Press, SWE, pp. 27-32. ISBN 978-1-61499-901-0

Abstract: In recent years, the pharmaceutical industry is seeing a movement towards the implementation of more efficient continuous manufacturing. This shift requires the development of in-line process analytical technologies to monitor and control the process at any given time. However, extracting reliable information from these sensors is a challenge. Among the available technologies, in-line image analysis is quickly gaining importance. This work presents an image analysis framework developed to address one of the main challenges of in-line image analysis: the presence of out-of-focus particles. Through two relevant examples such as the characterisation of a system of microparticles of mixed shapes and the monitoring of a common operation in the pharmaceutical industry such as the wet milling process, the benefits of incorporating this technique are assessed. The realtime analysis of imaging data in combination with other simultaneously-acquired quantitative data streams enables the user to make informed decisions and implement enhanced control strategies.

Note: I have provided the original version of the image processing framework, the image processing technology and consulting, MATLAB programming, clustering and statistics generation, domain decomposition, object classification.

See: This resource, Full text

Year 2017

2017-11 Invent a novel ultrasonic imaging algorithm - the Ply Resolving Method

Challenge: The classic Total Focusing Method (TFM) does not work well for imaging aerospace multilayer carbon fibre composite materials. In fact, it barely works at all.

Action: I explain why the TFM fails on via the assumption of point-like reflectors in the image space: In a multilayer carbon fibre composite, surface-like reflectors dominate, and these do not obey point-like-reflector assumptions, catastrophically obscuring the processed image of actual defects. I propose a new algorithm - a Ply Resolving Method that uses different assumptions, more in line with the reality of the problem at hand. I write a report on the principles of the new algorithm. I implement the new algorithm in MATLAB, and then CUDA.

Result: The new method is demonstrated theoretically and gives promising results. See here for more details. The work is aborted because I move to Ultrahaptics.

Skills used: Expertise in physics of ultrasound, python, MATLAB, CUDA, mathematics, initiative.

2017 present the results of the DopplerAI project

Notable event: Along with my student, Jianlin Cao, we present the results from the successful DopplerAI project to the guests.

2017 cueTFM gets adopted by other researchers

Notable event: My student, Tim Lardner, adapts my cueTFM work to his imaging problems and re-publishes the code here. A number of his publications suggest that he is the author of the cueTFM, some even contain identical typos. That’s sad🥺. This is the 3rd person that did that to me in my professional career. Still, imitation is the sincerest form of flattery 😊

2017 Receive a Leadership Award

Notable event: I complete the training and exercises in 1st line leadership development. See the programme and the award certificate here

2017 Calibration of ultrasonic phased arrays for industrial applications

Publication: Marcus Ingram, Jerzy Dziewierz, Anthony Mulholland, A. Gachagan, Calibration of ultrasonic phased arrays for industrial applications

See also: Researchgate publication page

2017 Monitoring crystal breakage in wet milling processes using inline imaging and chord length distribution measurements

Publication: Okpeafoh Stephen Agimelen, Vaclav Svoboda, Jerzy Dziewierz, Bilal Ahmed, Javier Cardona, and 8 others, under direction of Jan Sefcik, Monitoring crystal breakage in wet milling processes using inline imaging and chord length distribution measurements

Abstract: The success of the various secondary operations involved in the production of particulate products depends on the production of particles with a desired size and shape from a previous primary operation such as crystallisation. This is because these properties of size and shape affect the behaviour of the particles in the secondary processes. The size and the shape of the particles are very sensitive to the conditions of the crystallisation processes, and so control of these processes is essential. This control requires the development of software tools that can effectively and efficiently process the sensor data captured in situ. However, these tools have various strengths and limitations depending on the process conditions and the nature of the particles. In this work, we employ wet milling of crystalline particles as a case study of a process which produces effects typical to crystallisation processes. We study some of the strengths and limitations of our previously introduced tools for estimating the particle size distribution (PSD) and the aspect ratio from chord length distribution (CLD) and imaging data. We find situations where the CLD tool works better than the imaging tool and vice versa. However, in general both tools complement each other, and can therefore be employed in a suitable multi-objective optimisation approach to estimate PSD and aspect ratio.

2017 Design of a 2D sparse array transducer for integration into an ergonomic transcarnial ultrasound system

Publication: Xiaotong Li, Jerzy Dziewierz, Paul Murray, R.L.O’Leary, Anthony Gachagan, Design of a 2D sparse array transducer for integration into an ergonomic transcranial ultrasound system

See also: Researchgate publication page

2017 Ultrasound Elastography: Performance Evaluation of Displacement Field Refinement Process for Freehand Compression

Publication: Aws Al-azawi, Jerzy Dziewierz, John Soraghan, Scott Inglis, Anthony Gachagan

Abstract: This work involves the use of medical ultrasound imaging and associated mapping of biological tissue elasticity to discriminate tissue regions that have been diseased. Displacement field is estimated using cross-correlation for RF-echo signals of before and after compression that have been windowed for an effective spatial resolution. Non-coherent scatterer motion is identified as a main issue that corrupts displacement estimation in terms of decorrelation noise. In this paper the corruption is alleviated using a novel displacement field refinement process that regularizes estimation outliers based on neighbour cells information. The performance of the refinement process is evaluated using freehand compression. Results show a superiority of refinement process against non-refinement and 2D median filter operations. Experiment scenarios attain a possibility of using freehand compression to differentiate hard inclusion which is considered as a diseased tissue region.

2017 Accurate 3D reconstruction of bony surfaces using ultrasonic synthetic aperture techniques for robotic knee arthroplasty

Contributions: Kerr, William and Rowe, Philip and Pierce, Stephen Gareth (2017) Accurate 3D reconstruction of bony surfaces using ultrasonic synthetic aperture techniques for robotic knee arthroplasty. Computerized Medical Imaging and Graphics, 58. pp. 23-32. ISSN 0895-6111

Abstract: Robotically guided knee arthroplasty systems generally require an individualized, preoperative 3D model of the knee joint. This is typically measured using Computed Tomography (CT) which provides the required accuracy for preoperative surgical intervention planning. Ultrasound imaging presents an attractive alternative to CT, allowing for reductions in cost and the elimination of doses of ionizing radiation, whilst maintaining the accuracy of the 3D model reconstruction of the joint. Traditional phased array ultrasound imaging methods, however, are susceptible to poor resolution and signal to noise ratios (SNR). Alleviating these weaknesses by offering superior focusing power, synthetic aperture methods have been investigated extensively within ultrasonic non-destructive testing. Despite this, they have yet to be fully exploited in medical imaging. In this paper, the ability of a robotic deployed ultrasound imaging system based on synthetic aperture methods to accurately reconstruct bony surfaces is investigated. Employing the Total Focussing Method (TFM) and the Synthetic Aperture Focussing Technique (SAFT), two samples were imaged which were representative of the bones of the knee joint: a human-shaped, composite distal femur and a bovine distal femur. Data were captured using a 5MHz, 128 element 1D phased array, which was manipulated around the samples using a robotic positioning system. Three dimensional surface reconstructions were then produced and compared with reference models measured using a precision laser scanner. Mean errors of 0.82 mm and 0.88 mm were obtained for the composite and bovine samples, respectively, thus demonstrating the feasibility of the approach to deliver the sub-millimetre accuracy required for the application.

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2017 In-line monitoring of particle size and shape from image-based measurements

Contributions: Cardona, J. and Ferreira, C. and McGinty, J. and Hamilton, A. and Agimelen, O.S. and Cleary, A. and Chen, Y.C. and Sefcik, J. and Michie, C. and Atkinson, R. and Andonovic, I. and Tachtatzis, C. (2017) In-line monitoring of particle size and shape from image-based measurements. In: ISIC20, 2017-09-03 - 2017-09-06, University College Dublin.

Abstract: Within the pharmaceutical industry, particle size and shape distributions are crucial properties of crystalline particles produced in crystallisation processes. They determine the success or otherwise of processes such as granulation, suspension treatment and drying, all involved in the manufacture of the final pharmaceutical product. Some properties of the final pharmaceutical product such as dissolution behaviour are also influenced by the particle size and shape distribution of its ingredients. Therefore, crystallisation processes need to be controlled in order to produce particles with the desired attributes (size and shape). This in turn requires an accurate characterisation of the particle attributes during the crystallisation processes. Traditionally, particle size and shape are determined by means of off-line measurements. However, these techniques only provide information on the final state of the process and involve intermediate processing steps (e.g. sampling, dissolution, drying) that can alter the properties of the particles before the measurement. In recent years, a range of in-line techniques has been developed to obtain in-situ and real-time information on the state of the process in a non-disruptive manner.

Note: I have provided the original version of the image processing framework, the image processing technology and consulting, MATLAB programming, clustering and statistics generation, domain decomposition, object classification.

See: This resource, Full text

Year 2016

2016 DopplerAI research receives funding

awaiting more details

2016 DopplerAI FEM simulations

awaiting more details

2016 Machine learning with hyperspectral data

awaiting more details

2016 Hyperspectral camera programming

awaiting more details

2016 High dynamic range, high SNR, phase matching 3MHz signal separator

awaiting more details

2016 Ultra-precision mirror servo

awaiting more details

2016 Databases and OPC for automation, data collection, storage, and machine learning

awaiting more details

Skills used:: OPC design, OPC deployment, C-sharp for MATLAB GUI programming, c-sharp for glue logic, virtual machine architecture design, virtual machine deployment, SQL design, SQL deployment, SQL query optimisation, SQL application for data science,

2016 Deliver seminar on hyperspectral imaging, Ross Priory

awaiting more details

2016 Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types

Contributions: Kerr, W. and Pierce, S. G. and Rowe, P. (2016) Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types. Ultrasonics, 72. pp. 165-176. ISSN 0041-624X

Abstract: Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3 mm, 2.9 mm and 2.0 mm respectively, while those for TFM imaging were 3.7 mm, 3.0 mm and 3.1 mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was established that the reduced error associated with the SAFT technique was associated with significant reductions in side lobe levels of approximately 24dB in comparison to TFM imaging, although this came at the expense of reduced resolution and coverage.

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2016 Bio-inspired frequency agile acoustic system

Contributions: Guerreiro, José and Jackson, Joseph C. and Windmill, James F.C.; (2017) Bio-inspired frequency agile acoustic system. In: IEEE Sensors 2016. IEEE, USA. ISBN 9781479982875

Abstract: Natural passive mechanical systems such as ear tympanic membranes may show active responses by incorporating feedback mechanisms which then affect their mechanical structure. In this paper, the moth’s auditory system is used as a biological model of inspiration. A smart acoustic system which alters its natural resonance frequency was developed. Experimental results, given by a proposed-built real-time embedded system, show time and amplitude dependency towards dynamic frequency adaptation according to the intensity of acoustic input signals.

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Year 2015

2015 Start a novel ultrasonic inspection paradigm

Challenge: Traditional ultrasonic inspection works by introducing an impulse of the elastic wave into the specimen, and then waiting for this impulse to come back. This places a fundamental limit on the speed of the inspection – the speed of sound.

Action: Instead of waiting for the impulse to come back, insonify the specimen a polychromatic omnidirectional wave, and then move the readout probe so quickly as to observe a Doppler effect. The spatially varying Doppler shift on reception is related to the location of the reflector.

Result: Inspection scanning speed is increased to previously unheard-of velocities. I obtain funding to start a targeted research programme A new paradigm for ultrasonic non-destructive inspection method. (short name: DopplerAI) I recruit a student to conduct experimental validation, which later proves successful beyond expectations. For a taster, see this and this.

Skills used: Initiative, invention, creativity, expertise in physics, MATLAB, mathematics, visualisation, technical communication, technical writing

2015 Developing a Data Acquisition, Analysis and Reporting System for an Academic Research Centre

Publication: Murray Norman Robertson, Thomas McGlone, Andrea Johnston, Alastair Florence, Blair Johnston, Jerzy Dziewierz, Christos Tachtatzis, Alison Cleary, Anthony Gachagan, Ian Andonovic, Jan Sefcik - Developing a Data Acquisition, Analysis and Reporting System for an Academic Research Centre

See also: Researchgate publication page

2015 Integration of in situ Imaging and Chord Length Distribution Measurements for Estimation of Particle Size and Shape

Publication: Okpeafoh Stephen Agimelen, Anna Jawor-Baczyska, John McGinty, Christos Tachtatzis, Jerzy Dziewierz, Ian Haley, Jan Sefcik, Anthony Mulholland, Integration of in situ Imaging and Chord Length Distribution Measurements for Estimation of Particle Size and Shape

Abstract: Efficient processing of particulate products across various manufacturing steps requires that particles possess desired attributes such as size and shape. Controlling the particle production process to obtain required attributes will be greatly facilitated using robust algorithms providing the size and shape information of the particles from in situ measurements. However, obtaining particle size and shape information in situ during manufacturing has been a big challenge. This is because the problem of estimating particle size and shape (aspect ratio) from signals provided by in-line measuring tools is often ill posed, and therefore it calls for appropriate constraints to be imposed on the problem. One way to constrain uncertainty in estimation of particle size and shape from in-line measurements is to combine data from different measurements such as chord length distribution (CLD) and imaging. This paper presents two different methods for combining imaging and CLD data obtained with in-line tools in order to get reliable estimates of particle size distribution and aspect ratio, where the imaging data is used to constrain the search space for an aspect ratio from the CLD data.

2015 Seeded Crystallization of β-l-Glutamic Acid in a Continuous Oscillatory Baffled Crystallizer Contributions: Naomi E. B. Briggs, Ulrich Schacht, Vishal Raval, Thomas McGlone, Jan Sefcik, and Alastair J. Florence,Seeded Crystallization of β-l-Glutamic Acid in a Continuous Oscillatory Baffled Crystallizer Abstract: A continuously seeded l-glutamic acid cooling crystallization process, in a continuous oscillatory baffled crystallizer, was designed and operated to deliver control over polymorphic form. Different feed solution concentrations and seed loadings of β-l-glutamic acid crystals were examined. Steady-state operation, based on particle size distribution and polymorphic form, was demonstrated consistently after two residence times. Where bulk supersaturation remained in the range 2–3, the polymorphic phase purity of the thermodynamically stable β polymorph was retained. However, when the bulk supersaturation exceeded this range to values of 3–8, primary nucleation of the metastable α polymorph was observed, and product crystals were a mixed phase. In the absence of seeding the system could not be operated without significant encrustation to the vessel surface thus leading to loss of control, whereas a continuously seeded approach allowed robust processing for at least 10 h.

2015 Image-based Monitoring for Early Detection of Fouling in Crystallisation Processes

Publication: Christos Tachtatzis, Rachel Sheridan, Craig Michie, Robert Atkinson, Alison Cleary, Jerzy Dziewierz, Ian Andonovic, Naomi Briggs, Alastair Florence, Jan Sefcik - Image-based Monitoring for Early Detection of Fouling in Crystallisation Processes

Abstract: Fouling or encrustation is a significant problem in continuous crystallisation processes where crystal deposits at surfaces impede heat transfer, increase flow resistance and reduce product quality. This paper proposes an automatic algorithm to detect early stages of fouling using images of vessel surfaces from commodity cameras. Statistical analysis of the pixel intensity variation offers the ability to distinguish appearance of crystals in the bulk solution and on the crystalliser walls. This information is used to develop a fouling metric indicator and determine separately induction times for appearance of first crystals at the surfaces and in the bulk. A method to detect process state changes using Bayesian online change point detection is also proposed, where the first change point is used to determine induction time either at the surface or in the bulk, based on real-time online measurements without using any predetermined threshold which usually varies between experiments and depends on data acquisition equipment. This approach can be used for in situ monitoring of early signs of encrustation to allow early warning for corrective actions to be taken when operating continuous crystallisation processes.

Note: I have provided sensor deployment, experiment software, data collection and warehousing (SQL), dashboards, visualisation and automation for this effort.

2015 Applying hyperspectral imaging to continuous processing of pharmaceuticals

Publication: Dziewierz, Jerzy and McGinty, John and Macfhionnghaile, Pol and Svoboda, Vaclav and Sefcik, Jan and Gachagan, Anthony and Nordon, Alison and Marshall, Stephen and Cleary, Alison (2016) Applying hyperspectral imaging to continuous processing of pharmaceuticals. In: Solving problems with spectral imaging, 2016-02-04 - 2016-02-04,

Abstract: In moving from batch to continuous manufacturing of pharmaceutical products, knowledge of all experimental variables is required to help control and achieve a stable system that yields a consistent product with the desired attributes. Spectroscopic tools are often used to provide point measurements at key points in the process. Here we demonstrate the applicability of Hyperspectral Imaging (HSI) to continuous nucleation processes. The objective of the work described here was to show how HSI can be used to monitor mixing processes by providing spatially discriminated near-infrared spectra, yielding vital process information that has only previously been estimated using simulation techniques such as computational fluid dynamics (CFD). Methods: Water (antisolvent) and an IPA/water mixture (solvent) containing dissolved paracetamol seed crystals were mixed in a tube by introducing the antisolvent jet at different flow rates, and the resulting mixing in the tube was imaged with an InnoSpec RedEye camera in the spectral range 950 to 1700 nm. Microscope images of the resultant crystals from each different flow rate were taken to confirm that differences in the final crystal product were observed. Machine learning techniques in the form of Support Vector Machine (SVM) analysis were used to analyse and automatically separate the spectral data of the solvent/antisolvent mix into the different components. Results: The antisolvent jet, which resulted in nucleation near the point of injection, could clearly be identified and therefore monitored after application of the SVM. Differences between different flow rates and concentrations were observed from the hyperspectral images obtained, and these differences carried through to the shape and size of the final crystals obtained. Conclusions: We have demonstrated the applicability of HSI and advanced data processing techniques to the monitoring of mixing dynamics, in particular those used in continuous pharmaceutical processing such as solvent/antisolvent crystallisation.

Note: I have provided mechanical design, electrical design, manufacture & deployment, experiment software, data collection, machine learning (hyperspectral image decoding), publication materials, conference speech to this effort.

See: This resource , Full text

Year 2014

2014 Automated Full Matrix Capture for industrial processes

Publication: Roy Hutton Brown, Ian Collison, Ben Dutton, Jerzy Dziewierz, Joseph C Jackson, Timoty Lardner, Charles MacLeod, Maxim Morozov, Stephen Gareth Pierce - Automated full matrix capture for industrial processes

Abstract: Full matrix capture (FMC) ultrasound can be used to generate a permanent re-focusable record of data describing the geometry of a part; a valuable asset for an inspection process. FMC is a desirable acquisition mode for automated scanning of complex geometries, as it allows compensation for surface shape in post processing and application of the total focusing method. However, automating the delivery of such FMC inspection remains a significant challenge for real industrial processes due to the high data overhead associated with the ultrasonic acquisition. The benefits of NDE delivery using six-axis industrial robots are well versed when considering complex inspection geometries, but such an approach brings additional challenges to scanning speed and positional accuracy when combined with FMC inspection. This study outlines steps taken to optimize the scanning speed and data management of a process to scan the diffusion bonded membrane of a titanium test plate. A system combining a KUKA robotic arm and a reconfigurable FMC phased array controller is presented. The speed and data implications of different scanning methods are compared, and the impacts on data visualization quality are discussed with reference to this study. For the 0.5 m2 sample considered, typical acquisitions of 18 TB/m2 were measured for a triple back wall FMC acquisition, illustrating the challenge of combining high data throughput with acceptable scanning speeds.

2014 Automation and mechanical design contract with Elektromix

Challenge:: develop a control system for a patented continuous food processing machine

**Action: **: Recognise requirements using an interview, write and budget a technical proposal, get stakeholder acceptance, design the files

**Result: ** The control system, and one mechanical subsystem is manufactured and tested on time, on budget, and on the scope.

Skills used: Technical and interpersonal communications, requirement elicitation, technical writing, digital automation design, Mitsubishi PLC programming, Solidworks 3D mechanical design, Solidworks 2D documentation, design for manufacture

2014 Inspection of complex components using 2D arrays and TFM

Publication: Ailidh Mcgilp, Jerzy Dziewierz, T.Lardner, A.Gachagan, Inspection of complex components using 2D arrays and TFM

Abstract: Inspection of welded components typical of the primary circuit pipework in nuclear power plants is essential to evaluate their integrity. The inspection surface of such components is often complex and non-planar, resulting in coupling issues for a conventional probe, with a fixed footprint. In general this instigates complex and lengthy data analysis to retrieve meaningful results. An efficient solution for inspecting such components is sought by using 2D arrays, collecting FMC and using TFM to construct the surface profile, which is then extracted and subsequently used to compose a TFM image of the component. The solution has been developed within the software platform cueART, designed to operate on GP-GPU processors, in a move towards real time imaging. The method has been used to inspect a 304n section of stainless steel with a surface representing the worst acceptable error of form expected in a practical inspection scenario. The results show the full surface of the test block can be reconstructed, as well as a range of artificial defects being accurately identified.

2014 Application of Conformal Map Theory for Design of 2-D Ultrasonic Array Structure for NDT Imaging Application: A Feasibility Study

Publication: Nishal Ramadas, Joseph C Jackson, Jerzy Dziewierz, R.L.O’Leary - Application of Conformal Map Theory for Design of 2-D Ultrasonic Array Structure for NDT Imaging Application: A Feasibility Study

Abstract: Two-dimensional ultrasonic phased arrays are becoming increasingly popular in non-destructive evaluation (NDE). Sparse array element configurations are required to fully exploit the potential benefits of 2-D phased arrays. This paper applies the conformal mapping technique as a means of designing sparse 2-D array layouts for NDE applications. Modelling using both Huygens’ field prediction theory and 2-D fast Fourier transformation is employed to study the resulting new structure. A conformal power map was used that, for fixed beam width, was shown in simulations to have a greater contrast than rectangular or random arrays. A prototype aperiodic 2-D array configuration for direct contact operation in steel, with operational frequency ~3 MHz, was designed using the array design principle described in this paper. Experimental results demonstrate a working sparse-array transducer capable of performing volumetric imaging.

2014 Inspection design using 2D phased array, TFM and cueMAP software

Publication: Ailidh McGilp, Jerzy Dziewierz, Timothy Lardner, and 4 others under guidance of Anthony Gachagan, Inspection design using 2D phased array, TFM and cueMAP software

Abstract: A simulation suite, cueMAP, has been developed to facilitate the design of inspection processes and sparse 2D array configurations. At the core of cueMAP is a Total Focusing Method (TFM) imaging algorithm that enables computer assisted design of ultrasonic inspection scenarios, including the design of bespoke array configurations to match the inspection criteria. This in-house developed TFM code allows for interactive evaluation of image quality indicators of ultrasonic imaging performance when utilizing a 2D phased array working in FMC/TFM mode. The cueMAP software uses a series of TFM images to build a map of resolution, contrast and sensitivity of imaging performance of a simulated reflector, swept across the inspection volume. The software takes into account probe properties, wedge or water standoff, and effects of specimen curvature. In the validation process of this new software package, two 2D arrays have been evaluated on 304n stainless steel samples, typical of the primary circuit in nuclear plants. Thick section samples have been inspected using a 1MHz 2D matrix array. Due to the processing efficiency of the software, the data collected from these array configurations has been used to investigate the influence sub-aperture operation on inspection performance.

Note: I am the only author of the cueMAP software package. I plan to open-source it at one point - watch this space.

See: This resource

Year 2013

2013-09 Elastography: Displacement field regularization and strain field smoothing of ultrasonic calibration raw data

Publication: A.B. Al-Azawi, J.Dziewierz, S.Inglis, J.J.Soraghan - Displacement field regularization and strain field smoothing of ultrasonic calibration raw data; Bioengineering13, University of Strathclyde 16-17th September 2013, page 62.

Skills used: Expertise in physics of ultrasound, Expertise in physics of elastic materials, technical communication, collaboration.

See also: Researchgate publication page

2013 A Design Methodology for 2D Sparse NDE Arrays using an Efficient Implementation of Refracted-Ray TFM

Publication: Jerzy Dziewierz, Timothy Lardner, Anthony Gachagan, A Design Methodology for 2D Sparse NDE Arrays using an Efficient Implementation of Refracted-Ray TFM

I consider this paper to contain one of my best contributions ever.

Abstract: An algorithm has been developed that allows extremely efficient calculation of the total time of flight of an acoustic ray through two layer media, taking into account the effects of refraction through a 3D non-planar surface. The approach has been implemented on GP-GPU hardware, and embedded within the Total Focussing Method (TFM) imaging algorithm. This new software module supports arbitrary location of probe elements, array element directivity, arbitrary curved interface between two media, arbitrary transmit/receive sequences and any 1D/2D/3D image size for reconstructing the ultrasonic image from raw RF ultrasonic data. This allows calculation of the Point Spread Function of the probe at a range of points in its field of view, in a practical timeframe. Methodology, performance benchmarks, and possible applications are discussed.

2013 contribute to a Thermosonics inspection project

Challenge an industrially funded project is struggling to make sense out of a CAD model provided by the industrial partner. The CAD file is abridged to avoid releasing trade secrets, but that makes it difficult to interpret correctly. Action: I take the CAD file, convert it to a suitable format, and assist in creating a FEM model in COMSOL using the model. I train a team member on using CAD tools and FEM tools. I assist in modelling results interpretation. Result: The progress on the project is accelerated. Team members trained up. I gain experience in technical collaboration. Skills used: mechanical CAD software, technical communication, collaboration.

2013 contribute to the Woodsonics project

Challenge: The EU-funded woodsonics project, is struggling to make sense out of the signals acquired with a prototype ultrasonic scanning system. Action: I develop a signal processing routine. I train the project workers on the theory behind it, and how to use it. Result: The progress on the project is accelerated. Team members trained up. I gain experience in low-frequency signal processing. Skills used: Expertise in physics of ultrasound, signal processing, software development, technical communication, technical writing, collaboration See example document produced.

2013 CUE procures a new phased array controller, 70k GBP

Challenge: CUE needs a new ultrasonic phased array controller. There are several options available on the market. Action: I provide detailed technical diligence. I visit the device manufacturers at their respective sites and conduct comparisons. I advise the project sponsor on which option to choose. Result: A suitable device is procured for the group. Skills used: Negotiation, Expertise in ultrasonic NDT, technical communication, technical writing, requirements elicitation, requirements negotiation.

2013 Represent the CUE to victors and externally

Notable event series: I am chosen to represent the Centre for Ultrasonic Engineering to external visitors.

Skills used: presentation, technical communication, technical writing

2013 Computationally Efficient Solution of Snell’s Law of Refraction

Publication: Jerzy Dziewierz, Anthony Gachagan, Computationally Efficient Solution of Snell’s Law of Refraction.

As of 2020-08, this received 8 good citations. I’ll take that.

Abstract: An algorithm for an efficient parallel implementation of Snell’s law of refraction, applicable to planar interfaces, is found by algebraic manipulation. The algorithm is tailored for general-purpose graphics processing unit (GP-GPU)-type processors. Numerical singularity in the solution is addressed. Performance is compared against other implementations. Application areas include real-time total focusing method implementation, phased-array probe computer-aided design (CAD), and data fusion.

See also: Researchgate publication page

2013 2D ultrasonic array transducer design to maximise coverage in composite material structures

Publication: Jerzy Dziewierz, Anthony Gachagan, 2D ultrasonic array transducer design to maximise coverage in composite material structures

See: This resource

Year 2012

2012-11-09 IEEE IUS conference in Dresden

awaiting further details

2012 Enhancing 2D phased array sensitivity and bandwidth using in-probe electronics

Publication: Jerzy Dziewierz, A.Gachagan, Enhancing 2D phased array sensitivity and bandwidth using in-probe electronics

Abstract: An in-probe electronics printed circuit board (PCB) has been designed and built to improve the electrical matching issue in 2D ultrasonic array design. Each array channel has a dedicated line driver and the design utilized has low power consumption and importantly, a small footprint. Thus, the design is compatible with NDE probes, in which 128 elements are typical. The in-probe PCB was evaluated using a piezoceramic element scaled to obtain a 1kΩ impedance. Connected to the line driver, but otherwise acoustically un-matched, un-backed, the pulse-echo response from this element was acquired. Experimental results show an approximate 50dB improvement in sensitivity and an enhancement in bandwidth from 14.4% to 22.5% when compared to the ceramic interfaced directly to a standard 2m coaxial cable.

See: this note

2012 an Application-specific design approach for 2D ultrasonic arrays

Publication: Jerzy Dziewierz, Anthony Gachagan, Natacha Lord, Anthony Mullholland,

Abstract: As the technology of 2D phased array probes develops in the direction of sparse location of the elements, developing a balance of image resolution, contrast, coverage, and cost of the system becomes essential. A software-hardware system has been built that allows estimating 3D coverage of the inspection with respect to image quality for a given probe design. GPGPU implementation of the algorithms enables calculations to be performed in a practical timeframe.

See: Full text

Year 2011

2011 TFM with refraction

awaiting further details

2011 BEAMSIM educational material

awaiting further details

2011 SAMULET cuTFMv4 demonstrated

awaiting further details

Year 2010

2010 Triangular pillars enabling hexagonal array structure for 2D NDE aplications

Publication: Jerzy Dziewierz, Nishal Ramadas, A.Gachagan, R.L. O’Leary, Hexagonal array structure for 2D NDE applications

Abstract: This paper describes a combination of simulation and experimentation to evaluate the advantages offered by utilizing a hexagonal shaped array element in a 2D NDE array structure. The active material is a 1–3 connectivity piezoelectric composite structure incorporating triangular shaped pillars—each hexagonal array element comprising six triangular pillars. A combination of PZFlex, COMSOL and MATLAB has been used to simulate the behaviour of this device microstructure, for operation around 2.25 MHz, with unimodal behaviour and low levels of mechanical cross‐coupling predicted. Furthermore, the application of hexagonal array elements enables the array aperture to increase by approximately 30%, compared to a conventional orthogonal array matrix and hence will provide enhanced volumetric coverage and SNR. Prototype array configurations demonstrate good corroboration of the theoretically predicted mechanical cross‐coupling between adjacent array elements (∼23 dB).

2010 Visit to Madrid’s University of Roma Tre and their ultrasound department

awaiting further details

2010 Ultrathin PCB as 2D phased array interconnect

awaiting further details

2010 Contribute to the NPCT2 (Woodsonics) project

awaiting further details

2010 Create TFM reference dataset from simulation

awaiting further details

2010 Penn State ONR conference

awaiting further details

2010 BINDT conference

awaiting further details

2010 QNDE conference

awaiting further details

2010 CUE procures LECOEUR OPEN phased array controller

awaiting further details

2010 IMAPS conference

awaiting further details

2010 Micro positioning rig for precision 2D phased array manufacture

awaiting further details

2010 Shear wave imaging using longitudinal mode phased array

With beautiful results, awaiting further details

2010 Effects of cabling technology on ultrasonic phased arrays

awaiting further details

2010 Computer vision lectures - integral transforms, morphological transforms, statistical denoising

awaiting further details

2010 A methodology for the design of triangular-cut piezoelectric ceramic composites for application in 2D hexagonal-element ultrasonic arrays for NDE applications

Publication: Dziewierz, Jerzy and Gachagan, Anthony and O’Leary, Richard and Hayward, Gordon (2010) A methodology for the design of triangular-cut piezoelectric ceramic composites for application in 2D hexagonal-element ultrasonic arrays for NDE applications. In: International Workshop on Transducers and Transducer Materials, 2010-05-11, Penn State University.

See: This resource

Year 2009

2009-11 Develop a special probe for the NPCT2 project, - using cuBeam

awaiting more details

2009-06 - cueBEAM is useable

awaiting more details

2009-02 New family member

Notable event: . -.. .. - . -.. is born to . -.. .. - . -.. and me.

2009 Leadership training, communicate-consultants

Training: “Assertiveness, Teambuilding, and influencing skills” - 3 full Day course with

2009 leadership training, Evision Wild

Training: “West country Initiative Leadership and Development outward bound course 2009” - Leadership and teambuilding skills - 3 full Day course by Evision Wild

2009 An annular array with fibre composite microstructure for far field NDT imaging applications

Publication: Nishal Ramadas, Jerzy Dziewierz, R.L.O’Leary, A.Gachagan, A.Velichko, P.D. Wilcox - An annular array with fibre composite microstructure for far field NDT imaging applications full text

Abstract: This paper describes the design and fabrication of a reduced element count annular array for far field NDT imaging applications, built with a random fibre piezoelectric composite microstructure. An annular array design is considered, spatially it offers axi-symmetric layout while reducing number of array elements, which could potentially result in a significant reduction in the cost and complexity of building an ultrasonic volumetric imaging system. Modelling and preliminary experimental results are presented to evaluate the feasibility of this approach.

2009 Numerical Optimisation of piezocomposite material properties using 3D finite-element modelling

Publication: Jerzy DZIEWIERZ, Anthony GACHAGAN, Richard L. O’LEARY and S.N. RAMADAS, “Numerical Optimisation of piezocomposite material properties using 3D finite-element modelling” // 16th International Congress on Sound and Vibration, 2009

2009 A 2D Ultrasonic Array design incorporating Hexagonal-shaped Elements and Triangular-cut Piezocomposite Substructure for NDE applications

Publication: Jerzy DZIEWIERZ, S.N. RAMADAS, Anthony GACHAGAN, Richard L. O’LEARY, G. HAYWARD, “A 2D Ultrasonic Array design incorporating Hexagonal-shaped Elements and Triangular-cut Piezocomposite Substructure for NDE applications” // IEEE International Conference on Ultrasonics, 2009, Rome

Full text here

Abstract: Contemporary 2D Ultrasonic arrays suffer from low SNR and limited steering capabilities. Yet, there is a great desire in the industry to increase the operational frequency, in order to enhance their volumetric imaging resolution. State-of-the art arrays use an orthogonal matrix of rectangular elements as this is a natural step forward from the conventional 1D array structure. The objective of this work is to evaluate properties of triangular, rather than rectangular ceramic pillars in a 1-3 connectivity piezoelectric composite for application in a hexagonal-element 2D array. A 3MHz prototype device exploiting new hexagonal substructure have been manufactured. Measured mechanical cross-coupling level is -21.9dB between neighbouring hexagonal elements, providing validation of simulation result. Corroboration between measured and FE modelled device behaviour is demonstrated.

Year 2008

2008 WAI PZFlex training, Leeds University

awaiting more details

PhD at University of Strathclyde

Notable period: This is my first year at the University of Strathclyde

Year 2007

2007-07 Masters’ thesis

Notable event: I finish writing, demonstrate and defend my MEng Thesis. See the details and full text here. Skills used: Technical communication, technical writing, automation, mechanical engineering, Solidworks, MATLAB, LabView, research

2007 IMIR final year

Notable period: This is my final year at the AGH IMIR

2007 The Face Asymmetry Index

Publication: “Indeks asymetrii twarzy - The Face Asymmetry Index” / Jerzy DZIEWIERZ, Maria WYKOWSKA // Zeszyty Studenckiego Towarzystwa Naukowego ; ISSN 1732-0925. - 2007 nr 13 s. 65-69. - Streszcz., Summ.. - Artykuly laureatów XLIV Sesji Studenckich Kól Naukowych Pionu Hutniczego Akademii Górniczo-Hutniczej / pod red. Leszka Kurcza i Andrzeja Goldasza ; red. nacz. Jadwiga Orewczyk ; STN. - Kraków : Wydawnictwo STN, 2007

2007 Awarded the Gold award of Stanislaw Staszic For outstanding university students

awaiting more details

2007 Selected for Socrates-Erasmus programme with Glasgow Caledonian University

Notable event: Socrates/Erasmus Exchange to Glasgow Caledonian University

2007 Developed the Mobile Robot Team Toolbox for MATLAB

Notable event: Developed the Mobile Robot Team Toolbox for MATLAB;

Challenge: Develop a software stack for control of mobile robots, using computer vision, packing it up as a toolbox.

Action: I succeed. See more details here

Skills used: Creativity, initiative, quick learning, software engineering, computer vision, project management

2007 additional activities

Notable activities:

Year 2006

2006 IMIR year 4/5

Notable period: This is my 4/5 year at the AGH IMIR

2006 Training in Memo techniques

Training: Course on memory and focus techniques, SPW School of Memory ;

2006 IAESTE Summer training

Notable event: IAESTE Summer Training: JKP Vodovod i Kanalizacia, Zrenjanin Developing automatic treatment dosage system for the town’s waterworks.

2006 Awarded the Silver Award of Stanislaw Staszic

Award: Silver Award of Stanislaw Staszic for outstanding university students;

2006 Assistant to Dean of faculty

First job in academia: Employer: AGH University of Science and Technology;

Title: Assistant . Responsibilities: Work on student’s handbook “Podstawy Automatyki” (“Introduction to Automatic Control Engineering”); Developing educational project “Inverted Pendulum with voice coil actuator”, which includes mechanical, electrical and real-time control design; Maintenance of laboratory equipment and occasional tutoring on laboratory equipment operation;

=== work in progress ===

# Things that I want to include in the timeline, but I need to find references first:

* The microcontroller-timers lecture, along with the tutorial materials and the video

* * The Image processing tutorial, along with the demo code for the Huygens transform

* The PyMC3 utilisation for experimental data scoring -- include the beautiful data pre-analysis (exploration) with connectivity figure
* My membership in Electron Club
* My exam in radio communications
* The presentations on passive phased array radar
* The PhD thesis
* The experimental rigs for CMAC
* The Masters thesis, and the presentation
* the moroteco toolbox, the manual, the screenshots
* The leadership course certificate

* Major software packages experience
	* MATLAB, Simulink
	* PZFlex
	* LabView
	* AutoCad
	* SolidWorks
	* Mathematica
	* Altium Designer/Protel
* Software engineering experience
	* Python + scipy, pandas, numpy, scikit,, pytorch, JAX, and more -- list all the relevant packages, apparently recruiters are told to ask about these specifically.
	* C
	* C-sharp
	* POVRay
	* HTML, CSS, markdown, RST
	* OPC
	* SQL

* Hobbies
	* Sports: Sailing - Inland Skipper license.
	* Music: Grand Piano player, and Choir artist (tenor);
	* Augmented learning
	* SuperMemo techniques
	* Fast Reading 
	* Wojakowscy method of memory training [](

* Books
	* Deep work 
	* Sapiens series by Yuval Harari
	* Feynman lectures
    * Sean Caroll lectures

This is my ResearchGate page:

Have a just cause! (Simon Sinek)