Laboratory Bench Research Articles

Addressing Environmental Challenges of Porphyrin Mixtures Obtained from Statistical Syntheses

AbstractInvited for this month's cover are the groups of Dominik Lungerich at the Yonsei University (Korea) and Norbert Jux at the Friedrich‐Alexander‐University Erlangen‐Nuernberg (Germany). The cover picture shows a laboratory bench, with instruments, equipment, and a chalkboard. Here, the question arises if in academic research exists a way to implement the philosophy of “reduce, reuse and recycle”. The recycle sign underlines the rising awareness for this topic, which is steadily gaining in importance. Especially in porphyrin sciences, using semi‐automated flash chromatography can decrease significantly the cost of consumables, such as chlorinated solvents and silica gel. With a re‐usable glass column for preparative separation, even the purification of statistical reaction mixtures can be managed, while reducing the waste and thus the environmental factor significantly. Read the full text of their Full Paper at 10.1002/cmtd.202000055.

Ways of constructing of measuring and starting elements of microprocessor devices of fast acting automatic transfer switch

Microprocessor devices of fast-acting automatic transfer switch (FATS) are widely spread in modern net-works to increase the reliability of power supply of industrial plants in case of short-term violations of normal power supply mode. Presence of motor load in such networks requires minimizing the power interruption time to provide more favorable conditions for self-starting of electric motors. However, currently existing operation algorithms of measuring elements of FATS devices are based on the decomposition of the measured signal by using a Fourier integral, and require observation interval equals to the period of the industrial frequency. The known directional elements that are used in microprocessor-based FATS devices do not ensure reliable operation of the device with asymmetric and nearby fault. Therefore, the purpose of the work is to increase the speed of operation of the algorithms of the measuring elements of microprocessor devices of FATS, as well as to increase the reliability of the starting directional element in case of nearby fault and deep voltage drops. To achieve this goal the author uses the method of computer simulation. The method of a full-scale experiment on a laboratory bench to verify the obtained theoretical results is used. The author improves the algorithm to determine the orthogonal components of the measured current and voltage signals by integral averaging of instantaneous discrete values of the measured signals and their derivatives over the observation interval with a duration of less than a half-period of the industrial frequency. The algorithm of the operation of the starting directional element in case of deep voltage drops caused by nearby fault in both the external and internal power supply network has been improved by using the main power supply voltage from the added memory element of the pre-fault measurement cycle as a reference voltage to determine the power direction. The obtained results show that the proposed algorithm for the operation of the measuring elements will make it possible to obtain the value of the phase and amplitude of the measured signal in a time equals to 0,005 s. and use of an improved starting directional element makes it possible to increase its reliability in case of deep voltage drops and asymmetric short circuits. The proposed algorithms of operation of the measuring elements and the starting directional element can be used in FATS devices.

Cover Picture: Addressing Environmental Challenges of Porphyrin Mixtures Obtained from Statistical Syntheses (Chemistry ‐ Methods 3/2021)

The Front Cover shows a laboratory bench, with instruments, equipment, and a chalkboard. Is there a way to implement the philosophy of “reduce, reuse and recycle” in academic research? The recycle sign underlines the rising awareness for this topic, which is steadily gaining in importance. Especially in porphyrin sciences, using semi-automated flash chromatography can decrease significantly the cost of consumables, such as chlorinated solvents and silica gel. With a re-usable glass column for preparative separation, even the purification of statistical reaction mixtures can be managed, while reducing the waste and thus the environmental factor significantly. More information can be found in the Full Paper by Dominik Lungerich, Norbert Jux and co-workers.

Regionally Influenced Content of Selenium and Its Capacity under Postoperative Myocardial Remodeling in Cardiac Surgery Patients

Selenium (Se) is an essential micronutrient in living organisms; however, some aspects of its metabolism and function remain unknown. Se deficiency causes significant disturbances in the cardiovascular system along with left ventricular (LV) fibrosis. Simultaneously, an understanding of pathways that influence Se role in heart failure progression is insufficient. Therefore, clinical studies are needed to characterize Se importance in developing post-infarct LV dysfunction and postoperative remodeling. In the Tomsk region, the level of Se in healthy people and the myocardium of patients with ischemic cardiomyopathy was close to normal. Quantitative chemical analysis of Se content in hair samples and LV myocardium was based on stripping voltammetry to determine mass concentrations of the micro-element. Nevertheless, a significant number of cardiac surgery patients showed negative dynamics of postoperative LV myocardium remodeling with the development of heart failure. We obtained preliminary results of a direct correlation between favorable outcomes of postoperative adaptive myocardial remodeling (AR) and maladaptive myocardial remodeling (MALR) with different Se concentrations in the myocardium. Simultaneously, about 84% of patients showed abnormal postoperative LV MALR in high Se in the myocardium. Further in-depth studies are required to translate novel data from the laboratory bench to the clinics.

Sulfaquinoxaline Oxidation and Toxicity Reduction by Photo-Fenton Process.

Sulfaquinoxaline (SQX) has been detected in environmental water samples, where its side effects are still unknown. To the best of our knowledge, its oxidation by Fenton and photo-Fenton processes has not been previously reported. In this study, SQX oxidation, mineralization, and toxicity (Escherichia coli and Staphylococcus aureus bacteria) were evaluated at two different setups: laboratory bench (2 L) and pilot plant (15 L). The experimental design was used to assess the influence of the presence or absence of radiation source, as well as different H2O2 concentrations (94.1 to 261.9 mg L−1). The experimental conditions of both setups were: SQX = 25 mg L−1, Fe(II) = 10 mg L−1, pH 2.8 ± 0.1. Fenton and photo-Fenton were suitable for SQX oxidation and experiments resulted in higher SQX mineralization than reported in the literature. For both setups, the best process was the photo-Fenton (178.0 mg L−1 H2O2), for which over 90% of SQX was removed, over 50% mineralization, and bacterial growth inhibition less than 13%. In both set-ups, the presence or absence of radiation was equally important for sulfaquinoxaline oxidation; however, the degradation rates at the pilot plant were between two to four times higher than the obtained at the laboratory bench.

Biosensors Based on Isothermal DNA Amplification for Bacterial Detection in Food Safety and Environmental Monitoring.

The easy and rapid spread of bacterial contamination and the risk it poses to human health makes evident the need for analytical methods alternative to conventional time-consuming laboratory-based techniques for bacterial detection. To tackle this demand, biosensors based on isothermal DNA amplification methods have emerged, which avoid the need for thermal cycling, thus facilitating their integration into small and low-cost devices for in situ monitoring. This review focuses on the breakthroughs made on biosensors based on isothermal amplification methods for the detection of bacteria in the field of food safety and environmental monitoring. Optical and electrochemical biosensors based on loop mediated isothermal amplification (LAMP), rolling circle amplification (RCA), recombinase polymerase amplification (RPA), helicase dependent amplification (HDA), strand displacement amplification (SDA), and isothermal strand displacement polymerisation (ISDPR) are described, and an overview of their current advantages and limitations is provided. Although further efforts are required to harness the potential of these emerging analytical techniques, the coalescence of the different isothermal amplification techniques with the wide variety of biosensing detection strategies provides multiple possibilities for the efficient detection of bacteria far beyond the laboratory bench.

Isolation of Healthy F4/80+ Macrophages from Embryonic day E13.5 Mouse Fetal Liver Using Magnetic Nanoparticles for Single Cell Sequencing.

In vivo erythropoiesis occurs in the erythroblast island niche (EBI), comprising of a central macrophage that attaches to and aids the maturation of erythroid progenitors into mature reticulocytes. Macrophages in hematopoietic tissue such as embryonic fetal liver are heterogeneous and express the cell surface protein F4/80. Earlier methods of isolating F4/80+ macrophages from hematopoietic tissue relied on FACS sorting, but the relatively low numbers of F4/80+ cells obtained after FACS sometimes led to poor RNA quality. Additionally, since EBI macrophages are attached to erythroblasts, care must be taken to avoid contamination with bound erythroblasts. We have developed a novel method for isolating F4/80+ cells from E13.5 mouse fetal liver using magnetic nanoparticles, which can be performed on the lab bench. During cell suspension and homogenization, we also add a peptide that disrupts erythroid macrophage interactions and generates F4/80+ single cells free of erythroid contamination. Thus, our protocol generates a population enriched in F4/80+ cells that are healthy and ready for sensitive techniques such as single cell sequencing.

ПРОТОТИПИРОВАНИЕ ЦЕНТРОБЕЖНЫХ МИКРОКОМПРЕССОРОВ МЕТОДАМИ АДДИТИВНЫХ ТЕХНОЛОГИЙ

In the fast-developing market of customer products, a development lead time becomes more and more critical. However, these technologies have limits. Also, the application of so-called additive manufacturing technologies, particularly FDM 3D printing, is limited by the materials used and the part’s quality. The significant advantage of additive manufacturing is building components without the use of molds or tools. The paper presents an experience of fast prototyping a centrifugal compressor using 3D printing with polymer plastics. 3D printing of parts has the main goal in this study to develop a structural and functional prototype for variation centrifugal compressors testing. Additive manufacturing technologies can fabricate centrifugal compressors with less labor and any configuration. Attention is paid to the choice of 3D printing technology, materials, and the influence of printing parameters on the product's mechanical properties. In conclusion, experimental results are presented for the prototype together with recommendations for serial manufacturing. Also, a laboratory bench is described where variant tests will be carried out. All this will allow the reader to interpret those solutions more reasonably and take into account the specifics in more detail when developing a technical requirement for centrifugal compressors testing.

From Operating Table to Laboratory Bench: The Path Toward Metastasis Research from the Clinical Setting.

Presence of metastasis translates unequivocally into worse prognosis for our patients. Translational medicine has been our response to offer patients better therapeutic options. This chapter aims to provide an overview for clinicians to send the necessary metastatic tissue on the right path toward the laboratory bench, overcoming biases and possible data misinterpretations derived from poor sample quality.

ОСОБЕННОСТИ ТЕРМОМЕХАНИКИ ПУЛЬСИРУЮЩИХ ПОТОКОВ ГАЗА ВО ВПУСКНЫХ СИСТЕМАХ С КАНАВКАМИ ПРИМЕНИТЕЛЬНО К АВТОМОБИЛЬНЫМ ДВИГАТЕЛЯМ

Reciprocating internal combustion engines (RICE) are widely used as heat engines for converting the chemical energy of a fuel into mechanical work on the crankshaft. Aerodynamic and thermophysical processes in gas exchange systems significantly affect the efficiency of the RICE. This paper examines the possibility of influencing the gas dynamics and heat transfer of pulsating gas flows in the inlet system by placing a channel with grooves. It is known that the presence of grooves in the channel leads to the formation of significant secondary vortices, which radically change the physical picture of the gas flow. The studies were carried out on a laboratory bench, which was a singlecylinder model of a turbocharged RICE. A system of measurements of basic physical quantities is described, taking into account their high dynamics. Techniques for processing experimental data are presented. Primary data on instantaneous values of gas-dynamic and heatexchange characteristics of pulsating flows are presented. It was found that the presence of a channel with grooves in the inlet system leads to a decrease in the degree of turbulence to 40 % and an intensification of heat transfer in the range of 5–50 % compared to the basic inlet system. A positive effect is shown in the form of an increase in engine power by 3 % when using the modernized system.

Experimental studies of the effect of a hybrid inverter on power quality

The integration of alternative energy sources and various technologies of distributed generation with power electronic converters in electrical networks leads to an increase in the diversity of the network, but at the same time to the tightening of the requirements of various standards, for example, a limited harmonic composition of the generated current, continuous operation of the device with voltage distortion, etc. Taking this fact into account, the paper presents the results of experimental studies of the effect of a hybrid inverter on power quality indicators at the point of common connection. A laboratory bench was developed. It consists of a three-phase hybrid inverter, a storage battery, a linear load in the form of an active resistance and a capacitor unit. The inverter has been connected to the power supply for parallel operation to supply the load in the form of active resistance. The modes of battery charging and power delivery to the network with two variations of the system resistance were investigated. The power output from the inverter varied from 500 W to 2 kW in the mode of generating electricity to the grid, and in the range from 50 to 300 W in the battery charging mode. As a result of laboratory studies, the dependences of the total harmonic current distortion (THDI) were obtained for various operating modes of the inverter and system resistances. On the basis of the obtained results, an algorithm for the selection of methods and means to ensure electromagnetic compatibility during operation of the load and a hybrid inverter with energy storage was developed. It makes it possible to reduce the effect of hybrid inverters on the voltage distortion of the supply network.

Functional nanomaterials, synergisms, and biomimicry for environmentally benign marine antifouling technology.

Marine biofouling remains one of the key challenges for maritime industries, both for seafaring and stationary structures. Currently used biocide-based approaches suffer from significant drawbacks, coming at a significant cost to the environment into which the biocides are released, whereas novel environmentally friendly approaches are often difficult to translate from lab bench to commercial scale. In this article, current biocide-based strategies and their adverse environmental effects are briefly outlined, showing significant gaps that could be addressed through advanced materials engineering. Current research towards the use of natural antifouling products and strategies based on physio-chemical properties is then reviewed, focusing on the recent progress and promising novel developments in the field of environmentally benign marine antifouling technologies based on advanced nanocomposites, synergistic effects and biomimetic approaches are discussed and their benefits and potential drawbacks are compared to existing techniques.

Real-time system architecture design practices

In this paper we give an overview of both hardware and software architectures of real time systems used in devices for various purposes — from lab bench contraptions to cars. The goal of the paper is to reveal separate classes of such architectures as well as to define preconditions for choosing a particular architecture.

Исследование пассивных средств защиты информации от утечки по акустоэлектрическим каналам в среде Matlab

Purpose: design of the passive device of the speech information protection from acoustoelectric leakage channels and study of the characteristics of protection device using a virtual laboratory bench developed in the Matlab environment. Methods: mathematical modeling using Matlab environment. Practical relevance: designed in the Matlab modeling environment: an equivalent circuit of the telephone set, which makes it possible to simulate acoustoelectric information leakage channels, schematic diagrams of passive protection devices for telephone sets that implement protection methods: limiting low-amplitude signals, filtering high-frequency injection signals and disabling acoustoelectric transducers, a virtual laboratory stand for research of the characteristics of protective device. Using a virtual laboratory stand, the main characteristics of the developed protection devices were studied and their performance was assessed when connected to the telephone network.

RESEARCH ON THE INFLUENCE OF HIGH-FREQUENCY, SUPER-HIGH-FREQUENCY ELECTROMAGNETIC AND THERMAL EFFECTS ON THE PROPERTIES OF YAREGSKAYA AND DEVONIAN PETROLEUM

Petroleum produced in different regions and fields differ significantly in quality. The organization of pipeline transport of petroleum streams of a various quality produced in different geographic regions, according to a system with a complex topological structure, is possible only when controlling the quality of petroleum in traffic flows, in particular, controlling such property of petroleum as viscosity. Petroleum viscosity has a decisive influence on the performance of pumping and power equipment. The characteristics of the main petroleum pipelines depend on content’s viscosity. By influencing petroleum viscosity, it is possible to change the results of hydraulic calculations of main petroleum pipelines and pumping and power equipment without changing the equipment themselves, therefore, the task of changing the rheological characteristics of the pumped petroleum is timely. In this work, for the first time, thermal, super-high-frequency electromagnetic (SHF EM), high-frequency electromagnetic (HF EM) methods of treating the Siberian Devonian commercial petroleum and commercial petroleum of the Timan-Pechora province — Yaregskaya are studied. Both petroleum were exposed to thermal, high-frequency and super-high-frequency electromagnetic treatment on unique laboratory benches assembled at the Bashkir State University. As a result of the carried out studies, it was discovered that electromagnetic treatment affects the rheological properties of these petroleum in the temperature range corresponding to the operating temperatures of main petroleum pipelines. The most effective was the EM HF method of exposure. The relaxation time of the rheological properties of Devonian and Yaregskaya petroleum after EM treatment is 5 days, which is substantial compared to the currently popular thermal heating. The results of preliminary heat treatment with subsequent cooling on the Devonian and Yarega petroleum showed less efficiency compared to the results of electromagnetic treatment. When temperatures reach 30 degrees Celsius and above, the effectiveness of thermal and EM methods of exposure for both petroleum is reduced to zero. Another problem that arises during the pipeline transport of Yaregskaya and Devonian petroleum is the formation of asphalt-resin-paraffin deposits (ARPD) on the inner walls of the pipeline, leading to the need for more frequent cleaning of the pipeline, higher energy consumption to ensure the specified productivity of the pipeline. EM processing has also become one of the methods for solving this problem. As a result of an experiment to determine the amount of deposits on the inner walls of petroleum pipelines without treatment and after EM exposure, it was revealed that HF EM treatment is a preventive method for combating ARPD for Yaregskaya and Devonian petroleum. For Yaregskaya petroleum treated with HF EM field, the ARPD value on the walls of the model pipeline was 6 times less than for untreated Yaregskaya petroleum. Thus, as a result of all the work carried out within the framework of the study, it was found that high-frequency and super-high-frequency electromagnetic processing methods are effective in the transport of Yaregskaya and Devonian petroleum, and, unlike the thermal method of exposure and the introduction of additives, they contribute to an increase in the productivity of petroleum pipelines by improving the rheological properties of petroleum for a significantly long period of time, as well as to a reduction in formation of ARPD on the inner walls.

Pulmonary Hypertension Clinical Trials and COVID-19: A Discussion With John Ryan and Roham Zamanian

Pulmonary Hypertension Clinical Trials and COVID-19: A Discussion With John Ryan and Roham Zamanian

From the Slaughterhouse to the Laboratory Bench: On the Ethics of Using Slaughtered Animals for Biomedical Research.

Is it ethically permissible to acquire biological materials from a slaughterhouse for biomedical research? This essay examines this question, using a recent, high-profile research program as a case study. Using roughly 300 decapitated pig heads acquired from a slaughterhouse, researchers reperfused the animals' brains and observed a variety of cellular and molecular activities. The study was exempted from review and oversight by the Institutional Animal Care and Use Committee (IACUC), on the grounds that the animals were already dead. This essay argues that the IACUC was mistaken in exempting the study from their oversight, and furthermore, that acquiring animals or their parts from a slaughterhouse for research purposes is unethical and should not occur again. Examination of the study within a broader societal context helps to illuminate why each of us has an ethical obligation to do what we can to abolish the vicious and cruel treatment endured by billions of animals every year on factory farms and in slaughterhouses.

Software implementation of a virtual laboratory bench for distance learning

The article discusses the functional development and integration into the educational process of a virtual laboratory stand, with the aim of digitalizing the educational processes of higher education without loss as educational services related to the completeness of mastering professional competencies in specialized engineering courses. The developed laboratory stand allows simulating technological processes implemented in an apparatus consisting of four connected tanks. Modeling such a complex technological process with many interconnected elements is necessary for the most detailed research and synthesis of automatic control systems for multiply connected objects. The program simulates two control loops, each of which can be switched to manual or automatic operation. To realize the maximum adequacy of the mathematical model, the program provides for the possibility of taking into account the influence of the actuators on the regulation process.

Diesel Engine Gearbox Fault Diagnosis Based on Multi-features Extracted from Vibration Signals

Abstract Engine vibration is the consequence of a combination of internal forces and external forces, and the vibration signals contain a variety of information, also it is easy measurement, low cost and strong robustness. Hence, one of the most common and promising methods in fault detection area is vibration analysis which is effectively used in diesel engine fault diagnosis. In this paper, a new fault diagnosis method for diesel engine with vibration signals analysis and feature extraction based on ensemble empirical mode decomposition combined with support vector machine was proposed. Firstly, the vibration signals are first preprocessed and the intrinsic mode functions containing fault information was obtained by ensemble empirical mode decomposition. Then, extracting a feature vector from the intrinsic mode functions, time-domain digital features combined with Hilbert marginal spectra as a feature vector of gearboxes. Next, the fault classification of gearboxes were identified by support vector machine. Finally, the effectiveness of the proposed method was proved through the comparative experiments based on a large number of samples from rotor laboratory bench, the results illustrate that the proposed method could identify the multiple faults information from the collected vibration signals under different system states of gearboxes accurately and effectively.

РАЗРАБОТКА ТЕХНОЛОГИИ ИЗГОТОВЛЕНИЯ И ПРОИЗВОДСТВО ИМПОРТОЗАМЕНЯЮЩЕЙ МНОГОФУНКЦИОНАЛЬНОЙ СИСТЕМЫ КОХЛЕАРНОЙ ИМПЛАНТАЦИИ ДЛЯ РЕАБИЛИТАЦИИ ПАЦИЕНТОВ С СЕНСОНЕВРАЛЬНОЙ ТУГОУХОСТЬЮ

This article deals with the results of work on the creation of an import–substituting technology for the production of domestic cochlear implants. Cochlear implantation is considered as a radical method for solving hearing problems, both in children and in the elderly. The experience of domestic operations was analyzed by interviewing patients who underwent the procedure of cochlear implantation. To solve the research problem, we analyzed the accumulated experience of domestic operations by interviewing patients who underwent the procedure of cochlear implantation. We will highlight the criteria for the success of improving the quality of life of patients, and we found a correlation between the success of improving the quality of life of a patient after surgery with the characteristics of the implant used. Based on the analysis of these correlations and a detailed study at the laboratory bench of the implant that most contributed to the improvement of the quality of life of patients, we proposed a configuration of a domestic device designed to replace a foreign analogue in medical practice.