Laboratory Implementation Research Articles

ИМПУЛЬСНЫЙ ВЫСОКОВОЛЬТНЫЙ ИСТОЧНИК НАПРЯЖЕНИЯ НА БАЗЕ ДВУХСПИРАЛЬНОГО МАГНИТОКУМУЛЯТИВНОГО ГЕНЕРАТОРА С УЛУЧШЕННЫМИ ХАРАКТЕРИСТИКАМИ

Relevance The paper proposes an original design of a high-voltage electromechanical two-spiral voltage source based on a magnetic accumulation generator (MAG) and a voltage multiplier with improved characteristics. In the multiplier, with the help of special switches, the addition of all voltages arising from the electrical explosion of conductors in separate inductive energy storage devices connected in parallel to the magnetic accumulation generator is carried out. A mathematical model and the results of mathematical modeling of the operation of the voltage source are presented, the calculated ratios will find application for practical use. In the course of the work, methods of the theory of electric circuits, magnetic field, elements of mathematical analysis and the theory of electrical oscillatory processes (beating, resonance, etc.) in complex circuits were used. As a result, a ratio is obtained that determines the maximum value of the beat frequency between two electrical circuits connected by a weak capacitive coupling, creating a magnetic accumulation generator with high microwave radiation and with the possibility of its regulation. The results of the work will be used in power engineering (an ice control unit, a shunt reactor to increase the power factor, etc.), mechanical engineering, medicine (cardiology), military equipment, etc. In the future, it is planned to use the obtained results of work in the direction of studying the use of a pulsed electromagnetic field for dewatering and desalting oil, which will lead to an increase in the efficiency of existing installations in practice. Aims of research Development of the design of a high-voltage electromechanical two-spiral voltage source based on a magnetic accumulation generator and a voltage multiplier with improved characteristics, theoretical and experimental studies with subsequent conclusions and recommendations. Studies of the proposed double-spiral MAG and the development of an event for its further practical application. Research methods Methods of mathematical modeling, research and testing of high voltage equipment. Results A pilot design of a high-voltage electromechanical two-spiral voltage source based on a magnetic accumulation generator and a voltage multiplier with improved characteristics is proposed, calculated ratios with experimental research and proposals for implementation in individual industries and testing laboratories are obtained on the basis of the created mathematical model. Keywords: magnetic accumulation generator, multiplier, electric explosion, simulation, liner, double-spiral solenoid, oscillatory process

A Gaming Laboratory for Understanding Strategic Behavior in Power Markets

Results of four-year experimental trials of a Gaming Lab for understanding power markets are presented in here. The main goal of Gaming Lab was to illustrate the effects of strategic behavior on electricity markets, recognize pricing mechanisms and analyse the issues that emerge from competitive electricity markets. Evidences for reproducibility of obtained results of experimental gaming are provided. Different scenarios for conducting the developed series of games are described and compared. We finally provide recommendations on Gaming Lab implementation and future developments that could enhance the Gaming Lab.

A Fast ISAR Tomography Technique for Fully Polarimetric 3-D Imaging of Man-Made Targets

The 3-D inverse synthetic aperture radar (ISAR) tomography is an enabling technique for applications such as the exact diagnosis of scattering mechanisms for complex targets. Nevertheless, current ISAR tomography solutions still suffer from problems such as the great computational complexity and optimal utilization of the signatures acquired from limited baselines. In this work, we propose a fast ISAR tomography technique for fully polarimetric 3-D imaging of man-made targets. A stack of 2-D complex-valued images with different baselines and polarizations is first obtained through a phase error calibration (PEC) process and graphic processing unit accelerated polarimetric filtered backprojection. A polarimetric state-space decomposition (P-SSD) algorithm is then developed which could provide joint 3-D reconstruction results with low computational complexity. Examples from both numerical multibaseline data for the Sandia laboratories implementation of cylinders (SLICY) benchmark model and the outdoor range dataset collected by the Georgia Tech Research Institute (GTRI) are presented to demonstrate the superior performance and the usefulness of the proposed technique.

Data-Centric Architecture for Self-Driving Laboratories with Autonomous Discovery of New Nanomaterials

Artificial intelligence (AI) approaches continue to spread in almost every research and technology branch. However, a simple adaptation of AI methods and algorithms successfully exploited in one area to another field may face unexpected problems. Accelerating the discovery of new functional materials in chemical self-driving laboratories has an essential dependence on previous experimenters’ experience. Self-driving laboratories help automate and intellectualize processes involved in discovering nanomaterials with required parameters that are difficult to transfer to AI-driven systems straightforwardly. It is not easy to find a suitable design method for self-driving laboratory implementation. In this case, the most appropriate way to implement is by creating and customizing a specific adaptive digital-centric automated laboratory with a data fusion approach that can reproduce a real experimenter’s behavior. This paper analyzes the workflow of autonomous experimentation in the self-driving laboratory and distinguishes the core structure of such a laboratory, including sensing technologies. We propose a novel data-centric research strategy and multilevel data flow architecture for self-driving laboratories with the autonomous discovery of new functional nanomaterials.

Moving average procedures as an additional tool for real-time analytical quality control: challenges and opportunities of implementation in small-volume medical laboratories.

IntroductionMoving average (MA) is one possible way to use patient results for analytical quality control in medical laboratories. The aims of this study were to: (1) implement previously optimized MA procedures for 10 clinical chemistry analytes into the laboratory information system (LIS); (2) monitor their performance as a real-time quality control tool, and (3) define an algorithm for MA alarm management in a small-volume laboratory to suit the specific laboratory.Materials and methodsMoving average alarms were monitored and analysed over a period of 6 months on all patient results (total of 73,059) obtained for 10 clinical chemistry parameters. The optimal MA procedures were selected previously using an already described technique called the bias detection simulation method, considering the ability of bias detection the size of total allowable error as the key parameter for optimization.ResultsDuring 6 months, 17 MA alarms were registered, which is 0.023% of the total number of generated MA values. In 65% of cases, their cause was of pre-analytical origin, in 12% of analytical origin, and in 23% the cause was not found. The highest alarm rate was determined on sodium (0.10%), and the lowest on calcium and chloride.ConclusionsThis paper showed that even in a small-volume laboratory, previously optimized MA procedures could be successfully implemented in the LIS and used for continuous quality control. Review of patient results, re-analysis of samples from the stable period, analysis of internal quality control samples and assessment of the analyser malfunctions and maintenance log have been proposed for the algorithm for managing MA alarms.

A focused review on Lyme disease diagnostic testing: An update on serology algorithms, current ordering practices, and practical considerations for laboratory implementation of a new testing algorithm

Lyme borreliosis or Lyme disease (LD) is the most prevalent tick-borne illness in the United States. Diagnosing LD can be challenging as symptoms can be nonspecific and the ability of laboratory tests to detect infection varies based on the duration of infection and the methodology used. To date, serology testing is the primary laboratory tool employed to aid in diagnosing LD. Since the mid-1990′s, a two-tiered algorithm has been recommended for the optimization of specificity while maintaining high sensitivity. This mini-review aims to provide an overview of LD diagnostic testing in North America, with an emphasis on serologic algorithms, in particular the modified two-tiered testing (MTTT) algorithm, along with a discussion on provider ordering patterns and practical considerations for implementation of MTTT.

Lessons Learned from Implementation of an Interferon Gamma Release Assay to Screen for Latent Tuberculosis Infection in a Large Multicenter Observational Cohort Study in Brazil.

ABSTRACTThe interferon gamma release assay (IGRA) has emerged as a useful tool for identifying latent tuberculosis infection (LTBI). This assay can be performed through testing platforms such as the QuantiFERON-TB Gold Plus (QFT-Plus) assay. This in vitro test has been incorporated into several guidelines worldwide and has recently been considered by the World Health Organization (WHO) for the diagnosis of LTBI. The possibility of systematically implementing IGRAs such as the QFT-Plus assay in centers that perform LTBI screening has been accelerated by the decreased availability of the tuberculin skin test (TST) in several countries. Nevertheless, the process to implement IGRA testing in routine clinical care has many gaps. The study utilized the expertise acquired by the laboratory teams of the Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil consortium during study protocol implementation of LTBI screening of tuberculosis (TB) close contacts. RePORT-Brazil includes clinical research sites from Brazilian cities and is the largest multicenter cohort of TB close contacts in the country to date. Operational and logistical challenges faced during IGRA implementation in all study laboratories are described, as well as the solutions that were developed and led to the successful establishment of IGRA testing in RePORT-Brazil. The descriptions of the problems identified and resolved in this study can assist laboratories implementing IGRAs, in addition to manufacturers of IGRAs providing effective technical support. This will facilitate the implementation of IGRA testing in countries with large TB burdens, such as Brazil.IMPORTANCE The IGRA has emerged as a useful tool for identifying persons with LTBI. Although the implementation of IGRAs is of utmost importance, to our knowledge there is scarce information on the identification of logistical and technical challenges for systematic screening for LTBI on a large scale. Thus, the descriptions of the problems identified and resolved in this study can assist laboratories implementing IGRAs, in addition to manufacturers of IGRAs providing effective technical support. This will facilitate the implementation of IGRA testing in countries with large TB burdens, such as Brazil.

Development of an In-House Rapid Antimicrobial Susceptibility Testing Protocol for Positive Blood Culture and Its Implementation in Routine Microbiology Laboratories.

Bloodstream infections (BSI) are associated with high morbidity and mortality and remain a leading cause of death. Blood culture (BC) including the identification and the antimicrobial susceptibility testing of the causative microorganisms should be performed as soon as possible. In this study, we developed an in-house rapid antimicrobial susceptibility testing (rAST) protocol for positive BC. First, the rAST was performed in the simulated positive BC of standard strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853) at three different times to assess the reproducibility and operability by dispensing four drops of BC broth onto a Mueller–Hinton agar plate after a positive signal. Furthermore, the rAST was performed in clinical positive BCs. The results of rAST at 4, 6, 8, and 18 h of incubation were compared with results of the standard 16- to 20-h disk diffusion method, and the preliminary breakpoints of the rAST method were established according to the inhibition diameter of sensitive strains and resistant strains. Finally, the rAST was performed in the simulated positive BC of clinical strains to evaluate the availability of the preliminary breakpoints. The rAST results of standard strains were distributed evenly at three different times. Among the 202 clinical strains used to establish the preliminary breakpoints, the number of zone diameters that could be read and interpreted (60, 87, 98, and 100%) increased with incubation time (4, 6, 8, and 18 h), and the categorical agreement was acceptable, with total error rates of 3.0, 2.3, 2.1, and 1.3% at 4, 6, 8, and 18 h of incubation, respectively. In conclusion, the in-house rAST protocol for positive BC can be implemented in routine laboratories. It provides reliable antimicrobial susceptibility testing results for BSI pathogens after 4–6 h of incubation.

Oil Spill Detection Using Fluorometric Sensors: Laboratory Validation and Implementation to a FerryBox and a Moored SmartBuoy

A large part of oil spills happen near busy marine fairways. Presently, oil spill detection and monitoring are mostly done with satellite remote sensing algorithms, or with remote sensors or visual surveillance from aerial vehicles or ships. These techniques have their drawbacks and limitations. We evaluated the feasibility of using fluorometric sensors in flow-through systems for real-time detection of oil spills. The sensors were capable of detecting diesel oil for at least 20 days in laboratory conditions, but the presence of CDOM, turbidity and algae-derived substances substantially affected the detection capabilities. Algae extract was observed to have the strongest effect on the fluorescence signal, enhancing the signal in all combinations of sensors and solutions. The sensors were then integrated to a FerryBox system and a moored SmartBuoy. The field tests support the results of the laboratory experiments, namely that the primary source of the measured variation was the presence of interference compounds. The 2 month experiments data did not reveal peaks indicative of oil spills. Both autonomous systems worked well, providing real-time data. The main uncertainty is how the sensors' calibration and specificity to oil, and the measurement depth, affects oil detection. We recommend exploring mathematical approaches and more advanced sensors to correct for natural interferences.

Integrating Scalable Genome Sequencing Into Microbiology Laboratories for Routine Antimicrobial Resistance Surveillance.

Antimicrobial resistance (AMR) is considered a global threat, and novel drug discovery needs to be complemented with systematic and standardized epidemiological surveillance. Surveillance data are currently generated using phenotypic characterization. However, due to poor scalability, this approach does little for true epidemiological investigations. There is a strong case for whole-genome sequencing (WGS) to enhance the phenotypic data. To establish global AMR surveillance using WGS, we developed a laboratory implementation approach that we applied within the NIHR Global Health Research Unit (GHRU) on Genomic Surveillance of Antimicrobial Resistance. In this paper, we outline the laboratory implementation at 4 units: Colombia, India, Nigeria, and the Philippines. The journey to embedding WGS capacity was split into 4 phases: Assessment, Assembly, Optimization, and Reassessment. We show that on-boarding WGS capabilities can greatly enhance the real-time processing power within regional and national AMR surveillance initiatives, despite the high initial investment in laboratory infrastructure and maintenance. Countries looking to introduce WGS as a surveillance tool could begin by sequencing select Global Antimicrobial Resistance Surveillance System (GLASS) priority pathogens that can demonstrate the standardization and impact genome sequencing has in tackling AMR.

Building a microneurosurgical laboratory in Latin America: challenges and possibilities.

Background: Training in microsurgical neuroanatomy is a priority for neurosurgical education. During the 20th century, microsurgical laboratories arose and provided a way to develop surgical skills. Few reports addressed the assembly, construction, and details of a training laboratory.Methods: We have conducted a literature review and searched legislation on the need to plan the structure of the laboratory.Results: We projected and built a laboratory through a public-private partnership. High-tech workstations and instruments were planned to meet the needs of residents, fellows, and student. All steps and materials were in accordance with the Brazilian legislation and articles previously selected.Conclusion: We described our experience and demonstrated the implementation of a micro neurosurgical skills laboratory.

Implementation of the wp@e-lab fex mooc in tenth grade students at the Liceo Integrado Fray Francisco Chacón in Sopó, Cundinamarca

At present, virtual and distance learning spaces have been developed in the search for different alternatives in the construction of experimental environments, among which e-Learning spaces and massive open and online MOOC courses stand out. The COVID-19 health emergency reflected the need to implement academic interaction activities at a distance; therefore, the educational institutions opted for the virtual and distance modality for the development of the curricula and programmatic content addressed in each of the areas of knowledge. Simulation-based virtual laboratories are one of the resilient alternatives. On the other hand, school institutions in Colombia do not have the necessary infrastructure or the financial and technology capacity for the creation of scientific laboratories. The international project World Pendulum Alliance proposes the creation of virtual learning environments, reinforcing the experimental field through the implementation of remote laboratories. For this purpose, an alliance is created between different universities in Europe and Latin America, with the aim of disseminating remote experimentation in Basic Sciences. Among the consortium of partner universities, the Universidad Nacional Abierta y a Distancia - UNAD is linked to the project and, among its dissemination activities, has created the ReEx-SDC Science Dissemination Center, led by researchers from the School of Basic Sciences, Technology and Engineering ECBTI. This article shows the results obtained from the MOOC course of the IST of the University of Lisbon at the Fray Francisco Chacón School in tenth grade students, with the objective of including remote experimentation in the tenth grade physics curriculum in the following school year.

Implementation of a remote laboratory for the identification of polymeric materials by means of physical properties analysis

Due to the strategies implemented to carry out the development of a correct teaching by virtual means, a methodological strategy of experimental tests was developed for the identification of polymeric materials through the identification of physical and chemical properties, with the objective of providing the engineering student a greater approach to the application of the scientific method and the activation of the capacity of reasoning and deductive thinking from the physical and chemical point of view. Therefore, the purpose of this research was to validate this strategy implemented with a group of engineering students, for this purpose, the strategy was implemented, and the results obtained by the students from the development of the experimentation were analyzed, the data were analyzed by means of nonparametric tests, in this case binomial test. Finally, it is concluded that the polymer identification test is feasible to be implemented as a remote laboratory, as a methodical strategy in teaching, since it allows the development of experimentation, in this case, the identification of polymeric materials, which present diverse physical properties.

What do you mean by learning lab?

Digital and innovation competencies are nowadays highly required for students and faculty members in higher education institutions. We therefore need environments that incubate innovative learning scenarios to develop these competencies. We conducted a design-based research with the dual objective to develop learning labs in four universities and to document the design and implementation process and the addressed challenges. In this paper, we describe the concept of learning lab and the process of its setting up based on the experiments and observations conducted in the four learning labs in Lebanon, Egypt, Tunisia and Switzerland. A learning lab is defined as a physical, digital and human space for observation, experimentation and evaluation, to rethink and enrich learning and teaching attitudes and practices at the university. A learning lab is an incubator of pedagogical innovation and digital learning structured on three dimensions: spaces, activities and communities. We also identify the main challenges for the design and implementation of a learning lab. These challenges consist of the institutionnalisation of the learning lab and building, growing and nurturing a learning community.

Rapid design and implementation of an adaptive pooling workflow for SARS-CoV-2 testing in an NHS diagnostic laboratory: a proof-of-concept study

Background: Diagnostic laboratories are currently required to provide routine testing of asymptomatic staff and patients as a part of their clinical screening for SARS-CoV-2 infection. However, these cohorts display very different disease prevalence from symptomatic individuals and testing capacity for asymptomatic screening is often limited. Group testing is frequently proposed as a possible solution to address this; however, proposals neglect the technical and operational feasibility of implementation in a front-line diagnostic laboratory. Methods: Between October and December 2020, as a seven-week proof of concept, we took into account scientific, technical and operational feasibility to design and implement an adaptive pooling strategy in an NHS diagnostic laboratory in London (UK). We assessed the impact of pooling on analytical sensitivity and modelled the impact of prevalence on pooling strategy. We then considered the operational constraints to model the potential gains in capacity and the requirements for additional staff and infrastructure. Finally, we developed a LIMS-agnostic laboratory automation workflow and software solution and tested the technical feasibility of our adaptive pooling workflow. Results: First, we determined the analytical sensitivity of the implemented SARS-CoV-2 assay to be 250 copies/mL. We then determined that, in a setting with limited analyser capacity, the testing capacity could be increased by two-fold with pooling, however, in a setting with limited reagents, this could rise to a five-fold increase. These capacity increases could be realized with modest additional resource and staffing requirements whilst utilizing up to 76% fewer plastic consumables and 90% fewer reagents. Finally, we successfully implemented a plate-based pooling workflow and tested 920 patient samples using the reagents that would usually be required to process just 222 samples. Conclusions: Adaptive pooled testing is a scientifically, technically and operationally feasible solution to increase testing capacity in frontline NHS diagnostic laboratories.

Comparison of laboratory methodologies to determine soil nitrogen mineralization from organic residues

Recycling organic waste for use as fertilizer requires prior knowledge of mineral nitrogen (N) availability for crops. Estimation of soil N release or potentially mineralizable N is an important tool for the design of fertilization strategies that aim to minimize the use of N fertilizer. The aerobic incubation method is considered a standard technique to measure soil potential to mineralize N. In this study, alternative methods of aerobic incubation were evaluated to help overcome its limitations (long time and equipment). In this regard, biological methods (anaerobic incubation at 7 and 14 days) and chemical extraction (hot KCl) procedures were examined. To determine potentially mineralizable N, a silty clay loam soil was fertilized with spent mushroom substrates and anaerobic digestates from different origins (C/N ratio of 4 to 38). Based on the results, chemical extraction emerges as a reliable alternative to the aerobic incubation method, particularly when the C/N ratio of the organic residues ranges from 12 to 15. Moreover, its implementation in routine soil laboratories is straightforward and faster, and it does not require any special equipment.

Didactic laser speckle experiments with a lensless camera

Laser speckles are granular patterns created through the interference of coherent light scattered by a rough surface. Besides comprising an appealing optical phenomenon, the speckle patterns enable applications in physical and biochemical measurements. This paper proposes didactic far-field (objective) speckle experiments using a visible laser source and a lensless webcam for implementation in optics labs or at home. Firstly, a ceramic mug works as the scattering surface to investigate the effect of the target-observation plane distance on the average size of light granules. Secondly, the speckle pattern deviations produced by the liquid inside the recipient are analysed to measure mass and temperature changes. Finally, the mug is replaced with a leaf to evaluate its biological activity based on the scattered light. Image processing tools carry out the quantification of speckle parameters like average size and correlation coefficient, achieving a good agreement between theory and practical results. The proposed far-field speckle experiments explore topics related to optics, instrumentation, and image computing straightforwardly, developing the desired skills for undergraduate and graduate students of physics and engineering courses.

Rapid design and implementation of an adaptive pooling workflow for SARS-CoV-2 testing in an NHS diagnostic laboratory: a proof-of-concept study.

Background: Diagnostic laboratories are currently required to provide routine testing of asymptomatic staff and patients as a part of their clinical screening for SARS-CoV-2 infection. However, these cohorts display very different disease prevalence from symptomatic individuals and testing capacity for asymptomatic screening is often limited. Group testing is frequently proposed as a possible solution to address this; however, proposals neglect the technical and operational feasibility of implementation in a front-line diagnostic laboratory. Methods: Between October and December 2020, as a seven-week proof of concept, we took into account scientific, technical and operational feasibility to design and implement an adaptive pooling strategy in an NHS diagnostic laboratory in London (UK). We assessed the impact of pooling on analytical sensitivity and modelled the impact of prevalence on pooling strategy. We then considered the operational constraints to model the potential gains in capacity and the requirements for additional staff and infrastructure. Finally, we developed a LIMS-agnostic laboratory automation workflow and software solution and tested the technical feasibility of our adaptive pooling workflow. Results: First, we determined the analytical sensitivity of the implemented SARS-CoV-2 assay to be 250 copies/mL. We then determined that, in a setting with limited analyser capacity, the testing capacity could be increased by two-fold with pooling, however, in a setting with limited reagents, this could rise to a five-fold increase. These capacity increases could be realized with modest additional resource and staffing requirements whilst utilizing up to 76% fewer plastic consumables and 90% fewer reagents. Finally, we successfully implemented a plate-based pooling workflow and tested 920 patient samples using the reagents that would usually be required to process just 222 samples. Conclusions: Adaptive pooled testing is a scientifically, technically and operationally feasible solution to increase testing capacity in frontline NHS diagnostic laboratories.

Calibration of a Digital Current Transformer Measuring Bridge: Metrological Challenges and Uncertainty Contributions

In this paper, we consider the calibration of measuring bridges for non-conventional instrument transformers with digital output. In this context, the main challenge is represented by the necessity of synchronization between analog and digital outputs. To this end, we propose a measurement setup that allows for monitoring and quantifying the main quantities of interest. A possible laboratory implementation is presented and the main sources of uncertainty are discussed. From a metrological point of view, technical specifications and statistical analysis are employed to draw up a rigorous uncertainty budget of the calibration setup. An experimental validation is also provided through the thorough characterization of the measurement accuracy of a commercial device in use at METAS laboratories. The proposed analysis proves how the calibration of measuring bridges for non-conventional instrument transformers requires ad hoc measurement setups and identifies possible space for improvement, particularly in terms of outputs’ synchronization and flexibility of the generation process.

A novel maximum power point tracking in partially shaded PV systems using a hybrid method

To exploit photovoltaic systems, a major point that merits attention is to find maximum output power for the efficiency increase. The output power of solar cells depends on the ambient temperature and intensity of solar radiation. The cloud phenomenon creates a partially shaded on solar arrays; in this condition, the power–voltage curve of a solar array has several local maximum points. When there is uniform radiation, conventional methods of maximum power point tracking (MPPT) can be used. However, these methods are not efficient in partially shaded, due to the existence of several Maximum Power Points (MPPs) in the power-voltage characteristic. In this paper, a novel method for MPP tracking under the partially shaded is proposed, which is a combination of observational tracking and constant–voltage methods. When there is uniform radiation, the tracking operation is observed and tracked by a fuzzy logic–based approach. The proposed method is based on the existence of a relationship between radiation intensity and MPP voltage. In the existence of this relationship, the MPP voltage can be calculated by measuring the intensity of radiation at any moment. In addition, partially shaded works using the constant-voltage method. To verify the simulation results, laboratory implementation was performed. The results show that with considering the MPPs, the output power increases about 10% while the partially shaded is applied.