bluuebunny/crossref_metadata_2025 huggingface dataset:
Bamboo fiber-based insulating paper: A potential choice towards greener power and paper industries
Authors: Song Shunxi , Wang Qianyu , Zhang Meiyung
Published: February 2023

Insulating paper is the key material utilized in ultra-high voltage (UHV) projects, and it affects the safe and stable operation of the whole power system. Cellulose fiber-based insulating paper, having the advantages of low price and environmental friendliness, has been widely used as the preferred insulating material for certain transformers. Bamboo, as a fast-growing raw material, has a favorable fiber length and its carbon sequestration is better than that of wood. Bamboo can be potentially used as a new raw material for insulating paper, thus promoting the green development of the power and paper industry. This article mainly discusses the challenges and potentials of bamboo fiber-based insulating paper and the opportunities of bamboo fiber-based paper materials.
PROSPECTS AND TRENDS IN THE DEVELOPMENT OF DEVICES AND METHODS BASED ON THE PHENOMENON OF SURFACE PLASMON RESONANCE IN THE INFRARED RANGE (REVIEW)
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Kachur N. V.
Published: January 2023

On the phenomenon of surface plasmon resonance (SPR) and its use for the study of gaseous and liquid substances, more and more papers are published in professional journals. These studies are used in clinical diagnostics, food industry, environmental monitoring. The advantages of SPR sensors include quick results, a small amount of analyte, the possibility of real-time measurement of such reactions as antigen-antibody, protein-protein, enzyme-substrate or inhibitor, protein-DNA, receptor-drug, protein-polysaccharide , virus protein and reactions of external stimulation of a living cell. The high sensitivity of the method is due to the properties of its resonant nature of plasmon-polariton oscillation. SPR devices are used in laboratory conditions and there is a potential possibility of further reduction of overall dimensions for use in field conditions. The use of SPR in the IR region of the spectrum has a number of advantages, namely: the laser light penetrates deeper into the sample, it becomes possible to study substances that are not transparent in the visible region, but transparent in the infrared, which allows working with larger research objects, provides a narrower characteristic of the SPR, which allows to more accurately determine the angle of the minimum of the SPR, and also requires the application of a thinner layer of gold on the glass chip, which reduces the cost of the analysis. The review analyzed literary sources and determined prospects for the development of devices and methods based on IR SPR, considered prospective materials of the sensitive element and prisms of the total internal reflection device according to the Kretchman scheme. It was determined that, in addition to precious metals (gold and silver), conductive metal oxides ITO, ZnO, CdO:Dy have the prospect of being used as materials for manufacturing the sensitive element of the sensor. Their compliance with the requirements for materials for maintaining the SPR was analyzed. It is shown that CdO:Dy has the greatest potential due to sufficient mobility and density of charge carriers. But in practice, the most common use is gold and silver, for which it is necessary to determine the optimal thicknesses for the IR range of SPR. Total internal reflection prisms (hereafter prisms) in SPR devices according to the Kretchman scheme are usually made of glass, but for the IR range it is advisable to consider other materials that are less sensitive to the temperature effect of the IR laser. The paper analyzes the dependence of the plasmon resonance parameters on the prism material. The possibility of using not only different brands of traditional glass, but also glass ceramics with practically zero coefficient of thermal expansion, semiconductor silicon and chalcogenide glass for the manufacture of prisms is shown.
APPLICATION OF PLASMONICS FOR THE ANALYSIS OF POLYDISPERSE SYSTEMS
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Dorozinska H. V.
Published: January 2023

Modern sensor technologies have advantages compared to other classical methods of analysis of liquid and gas environments, in particular, fast analysis and a small volume of the analyzed sample, high sensitivity, the ability to detect the analyzed substance in a polydisperse environment due to the specificity of the sensor. Plasmonics is one of the leading scientific directions, which is actively used in sensor technologies for the development of highly sensitive analytical devices and systems. Precision analytical devices based on SPR are used for research in the food, chemical, pharmaceutical industry, agriculture, medicine, and ecology. However, the interpretation of the measurement result is somewhat complicated when analyzing complex polydisperse systems and the presence of an interferent in the sample, which affects the value of the sensor signal. Therefore, there is a need to study, in particular, liquid polydisperse systems using models of approximate environments and using additional technologies to increase the specificity of the analyzed component by using receptor surfaces. The review provides information on the current state of polydisperse systems research using the example of milk - one of the most common food products. Sensitive, fast and efficient quantification and monitoring systems play a key role in the determination of harmful impurities in dairy products. The need to detect antibiotics with a minimum concentration in food products, in particular in dairy raw materials, which are complex polydisperse systems, is an important scientific problem. Such requirements give rise to the need to develop reliable, highly sensitive analytical methods. In addition, there is a huge demand for rapid analytical devices to detect antibiotic residues in milk samples on the farm before the raw material is sent to the factory, because after sending directly to the factory, in case of antibiotic detection, a large batch of milk is missing, which leads to excessive costs.
InSb Photodiodes (Review. Part V)
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Tetyorkin V. V.
Published: January 2023

The results of research on the recombination of non-equilibrium charge carriers in n-InSb single crystals are analyzed. It is shown that the Shockley-Reed-Hall recombination models described in the literature are unable to explain the experimental results obtained in single crystals of applied quality, which are used to create infrared photodiodes. The proposed model of recombination with the participation of two independent levels, one of which is an acceptor. The model is based on the results of experimental studies of the lifetime in n-type InSb obtained from measurements of photoconductivity relaxation under pulsed laser excitation in the temperature range of 77-250 K. For the measurements, n-type conductivity single crystals grown by Czochralski method and obtained from several sources were used. The concentration of charge carriers in the samples at a temperature of 77 K varied within 1014-1016 cm-3. The kinetics of photoconductivity was studied in n-InSb samples before and after the formation of diffused p+-n junctions. The diffusion temperature of the cadmium acceptor impurity varied between 380 and 420 0С. It is shown that in the samples after the formation of the p-n junction, the lifetime can be limited by the effect of the trapping of minority carriers to the acceptor level, which is located at a distance of 60 meV from the bottom of the conduction band. The model allows describing the dependence of lifetime on temperature and carrier concentration in the doping range of 1014 - 1016 cm-3. From the comparison of stationary and transient lifetime, conclusions are drawn regarding the existence of the effect of the trapping of minority carriers in the material of n-type conductivity, which is responsible for the excess tunnel current in photodiodes, generation-recombination and low-frequency 1/f noise. It is assumed that acceptor traps can be caused by the generation of dislocations during the formation of a diffused junction.
SPECIALIZED PHOTOMETER FOR MONITORING THE BRIGHTNESS AND ILLUMINATION OF THE ROAD SURFACE
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Shabashkevich B. G.
Published: January 2023

A specialized optical system for the Ekotensor-03 photometer was developed and based on it, the concept of direct measurements of the distribution of the brightness of the road surface, created, among other things, by LED light sources, was built. The specialized photometer (brightness meter), with readings directly in brightness units, was created on the basis of the Ekotensor-03 photometer of Ukrainian production, equipped with the appropriate optical system and mechanical devices. At the same time, instead of measuring brightness at a distance of 160 m at an angle of the receiver's field of view of 2 arc minutes vertically and 20 horizontally, it is suggested to bring the photometer closer to the illuminated planes, the brightness of which is determined, at a distance that eliminates the contradiction associated with the requirements of the DSTU and the problem of a small signal level generated by the photometric head at a long distance from the measurement object is removed. Taking into account the ultra-low levels of brightness during measurement in accordance with the requirements of the current DSTU and DBN, which is an obstacle even when carrying out measurements in controlled laboratory conditions of leading research centers, the proposed method has all the necessary advantages (high measurement accuracy, ease of implementation in non-laboratory (real) conditions, adaptability of the measurement model to the requirements of regulatory documents). The brightness measurement range of the photometer with a specialized optical system is from 0.1 Kd/m2 to 105 Kd/m2. The limits of the permissible main relative error of brightness measurement created by an arbitrary source do not exceed ± 5%. The uncertainty of calibration is 1.5%. The metrological support of the device is implemented with traceability to the national standards of the NSC "Institute of Metrology", in particular, to the primary standard of the unit of light power.
SENSING ELEMENT OF THE SURFACE PLASMON SENSOR WITH THERMAL MODIFICATION OF THE STRUCTURAL PROPERTIES OF THE POLYMER SUBSTRATE
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Kostyukevych S. O.
Published: January 2023

The development of an effective sensing element (ChE) sensor with a prism type of excitation (Kretchman configuration) of surface plasmon resonance (SPR) in a gold film and a mechanical survey of the angle of incidence of monochromatic light based on a polymer substrate is based on a combination of radiation binding schemes using a prism and a lattice to prevent losses in the active metal film. Replacing the glass substrate with a polymer one has reduced the cost of ChE, led to increased sensitivity and simplification of its manufacturing technology, which does not require the use of intermediate adhesion layers. Additionally, we applied a thermal method of modifying the optical and structural properties of the substrate – hot pressing of the matrix, which contained a periodically nanostructured surface relief in the form of a diffraction two-dimensional (2D) lattice. The original 2D lattice was recorded on photoresist-covered (Shepley 1805) glass plates using the method of two-beam interference (He-Cd laser, = 440 nm) at double exposure (time 2040 s, power 20 mW/cm2) of the sample with a rotation of 90. Characteristics of ChE on an optical polycarbonate substrate (d = 2.25 mm, n = 1.58 at ( = 650 nm) after hot pressing, which contained a flat and periodically nanostructured surface in the form of a diffraction 2D lattice, followed by the deposition of a thin (d 40 nm) layer of gold on them was examined using an atomic force microscope (AFM) and the device "Plasmon". AFM studies have shown that the technological technique used made it possible to obtain lateral-ordered structures in the form of pyramids with calculated parameters – a period of 422435 nm (spatial frequency of about 2350 lin/mm) and a relief depth of 7090 nm. However, the preservation of a wave-like relief (about 300 nm) on a flat part of the surface and double ray refraction of the polymer substrate, encourage optimization of the hot pressing process using the resulting matrix on polymer substrates of smaller thickness.
PECULIARITIES OF ULTRASOUND EFFECT ON 2DEG AND 3DEG CHARGE CARRIERS ELECTRONIC TRANSPORT IN GaN/AlGaN/GaN/AlN HETEROSTRUCTURES
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Olikh Ya. M.
Published: January 2023

We have conducted the temperature and amplitude dependencies of the charge carriers concentration and its mobility analysis in GaN/Al0,2Ga0,8N/GaN/AlN on sapphire structures growing MOCVD method under the ultrasonic loading (longitudinal waves, fUS = 9 MHz). We found out the temperature peculiarities of electronic characteristics changes, it is allowed us to consider our system as complex with parallel conduction channels. In order to study the effect of ultrasound loading separately on both the flow of 3DEG and 2DEG charge carriers, a mathematical operation of separating these flows was carried out. It is shown, that at high temperatures (Т ˃ 200 K), 3DEG conductivity prevails, which has a thermal activation character and is described by the acoustically induced transformation of the metastable DX center. At temperatures (T ˂ 150K), 2DEG conductivity prevails. Thus, AlGaN/GaN and GaN/AlGaN boundaries can exhibit 2DEG conductivity (σ2D), while film layers (GaN buffer and AlGaN barrier layer are 3DEG conductivity (σ3D)). In the AlxGa1-xN structures containing DX centers, under US loading, there is a periodic change in the distance between the positions of the donor atom. Here, the determining mechanism is tunneling, the nature of which is related with dislocations. The horizontal sections observed in the experiment arise as a result of the tunnel emission of charge carriers through the quasi-resonant level. It was established that 3DEG and 2DEG charge carriers differ in the nature of temperature changes in concentration (with increasing temperature, there is an increase in 3DEG concentration and independence from temperature in 2DEG concentration) and mobility (decrease in 3DEG, but increase in 2DEG). It is shown that the influence of ultrasound in both cases, both for 3DEG and for 2DEG, of charge carriers is qualitatively similar - there is an increase in the 3DEG and 2DEG carriers concentration and a decrease in the absolute values of 3DEG and 2DEG mobility. Acoustically induced changes in electrical parameters most likely occur near dislocations that actively interact with ultrasonic waves.
SPECTRAL POWER DISTRIBUTION OF LEDS AND POUCH PHOTOMETRY
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Nazarenko L. A.
Published: January 2023

The rapid development of lighting technologies, which has been observed in recent decades, is definitely connected with the widespread introduction of LED light sources. At the same time, if in the early days the energy efficiency of LEDs was noted, now the use of certain spectral characteristics of such sources is on the agenda. At the same time, methods and means of photometry are expanding, in addition to photopic and scotopic, mesopic photometry is also developing. Lighting standards based on the photopic function of light efficiency do not fully cover visual perception. Therefore, it is relevant to determine the characteristics related to twilight photometry, which is considered in the paper. In fact, we are talking about a new lighting paradigm - a transition from the use of a single function of light efficiency - photopic, to a multifunctional one, when one or another function of light efficiency is used, which is dictated by a specific lighting task and at the same time is regulated by the corresponding light standards. Thanks to this methodology, it is possible to increase efficiency not by literally reducing power consumption, but by taking into account the spectral characteristics of light sources. If we also take into account the emergence of a new distribution - the response curve of melatonin suppression, which has become the basis of circadian photometry, then this approach will contribute to solving the current problem of human-centric lighting. It is important to regulate light sources according to the S/P factor in order to minimize the consumption of electrical energy and increase visual efficiency. The S/P ratio is a convenient and simple way of characterizing the spectral composition of the radiation provided by various light sources. It is the influence of any spectral distribution of brightness on mesopic photometric values that can be characterized by the S/P value. The ability to calculate the S/P factor for any light source, as well as to conduct a survey of widely distributed light sources, is very important.
TRANSITION LAYER AND LATERAL PHOTO-EMF IN SEMICONDUCTOR HETEROSYSTEMS
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Shekhovtsov L. V.
Published: January 2023

A photo-emf in the NbN–GaAs Schottky contact samples studied. This photo-emf is generated along the metalsemiconductor interface. It is shown that a semiconductor transition layer formed near the Schottky contact interface has a pronounced effect on the form of spectral characteristics. The feature of the photoemf spectral characteristics is a variations its appearance when changing the thermal annealing temperature of the studied heterosystems. If the spectral characteristic has one maximum and amplitude, which several times exceeds the amplitude of a significant characteristic, which means the formation of a transition layer in the Schottky contact depletion area with high conductivity, compared with a quasine-neutral region of a semiconductor. A complicated alternating form of spectral characteristics of the photo-emf is related to contributions to the measured signal from several components that are generated at potential barriers of the metalsemiconductor heterosystem. Illumination of samples on the metal side results in change of the form of spectral characteristics and reversal of sign of photo-emf. This is caused by variation of interrelation between the photo-emf components that are generated in the heterosystem layers with different conductivities. For the samples annealed at Т = 900 С, the photo-emf changes its sign near the GaAs absorption edge. It was found that thermal annealing at Т = 950 С results in increase of relative nonuniformity of the depletion region thickness, while the sign of the photo-emf spectral curve does not change. In this case, considerable effect of band bending nonuniformity in the depletion region of the heterosystem under investigation on the character of lateral photo-emf distribution is retained.
Analysis Of The Sources Of Uncertainty On The Way To Creating A Luminance Unit Standard
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Kupko O. D.
Published: January 2023

A situation, folded in Ukraine with measurements of brightness, is considered, in particular, absence from 1991 of the State primary standard of units of brightness, from after what reproducing of unit of brightness takes a place at the level of photometers - workings standards and workings facilities of measuring of illumination. On the example of the typical setting described in detail analysed a vagueness, arising up at reproducing units of brightness. The method of reproducing of unit of brightness is described. The basic a uncertainty, related to the sensitiveness of photometer, based on the harmonized document was analyzed. Additionally in theory appraised a uncertainty, arising up from the difference of geometry of distribution of rays at calibration of photometer and at reproducing of unit of brightness, and similarly from distinction in the temperature condition of lamp. On the basis of experimental researches appraised a uncertainty, arising up from unideality of diagram orientation of radiation from a diffuser. On the basis of the offered method, measurings are appraised a uncertainty, the arising up from inaccurate knowledge areas of diaphragms are got. On the basis of the conducted estimations of the budget of uncertainty is analysed. Consequences in which using will result for realization and calibration the use as a source of screen of monitor are analysed. Expedience of creation of separate branch of measurings of brightness is marked on basis.
TECHNNOLOGIES FOR CREATING SURFACE RELIEFS ON FILMS OF CHALCOGENIDE SEMICONDUCTORS
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Kryuchуn A. A.
Published: January 2023

A review of recent progress in optical recording of surface relief structures in the films of amorphous chalcogenides is presented. Various aspects related to light-driven macroscopic effects for these materials (changes in solubility, local evaporation, volume changes, mass-transport and so on) where stimulated surface patterning takes place due to the interaction of matter with light are discussed. Experimental data describing different aspects of surface relief patterning using direct recording by tigtly focused single or structured light beams are summarized.
SPECTRAL PARAMETERS OF QUASI-MONOCHROMATIC LEDS FOR LIGHTING SYSTEMS WITH TUNABLE SPECTRAL COMPOSITION
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Pekur I. V.
Published: January 2023

In this paper, the influence on the parameters of the synthesized light of the full width at the half-height level of the spectra of additional quasi-monochromatic LEDs for LED clusters with adjustable correlated color temperature built on the basis of a combination of white broadband high-power LEDs and quasi-monochromatic LEDs with peak wavelengths of 474 and 600 nm is considered. It was shown that the construction of LED clusters with adjustable CCT with an increase in the full width at half the height of the spectrum of quasi-monochromatic LEDs increases the CIE Ra of the resulting radiation. At the same time, the spectrum of quasi-monochromatic LEDs with a smaller full width at half the height of the spectrum has a greater influence on the change in the CCT of the resulting light, and therefore the contribution of the luminous flux of such LEDs to the resulting radiation will be less. Given that the parameters of the light sources used to create the light environment in which a person is, depends on the secretion of the hormones melatonin and cortisol, which significantly affect the well-being and psychophysiological state of a person, it is becoming increasingly common to build lighting systems with adjustable correlated color temperature. At the same time, achieving high luminous efficiency of modern LED lighting systems often negatively affects the quality parameters of the light environment they create. Non-compliance of the spectral composition of light with human needs at a certain time of day can adversely affect the natural cycles of human biorhythms. The results of the work contribute to the development of further research in the direction of finding new ways to build modern powerful energy-efficient LED lighting systems.
DETERMINATION OF THE THICKNESS OF PLASMON CARRIER LAYERS BY THE PHOTOMETRIC METHOD
Authors:   V. Lashkaryov Institute of Semiconductor Physics of NAS of Uraine, Dorozinska H. V.
Published: January 2023

The influence of design and technological factors, in particular, the deviation of the thickness of the plasma-carrying layer from the nominal value, introduces uncertainty into the measurement by the method of surface plasmon resonance. The effect of the thickness of nanoscale films of surface plasmon resonance sensors on the characteristics of these sensors is shown in the work using the method of numerical modeling. An experimental study of the transmission spectra and reflection characteristics of gold films of different thicknesses was conducted and consistency with theoretical calculations was established. Transmittance coefficients were used as an informative parameter for estimating the thickness of nanosized gold films of surface plasmon resonance sensors. Not only the difference in the angular positions of the resonance and the intensity of the reflected light in it, but also the different width of the resonance characteristics in the region of the minimum and the shape of the intensity graph at angles smaller than the critical one are characteristic for samples with different thicknesses. The correlation coefficient between the thickness of the studied samples and the corresponding transmission coefficients at a wavelength of 532 nm is r = - 0.943. This means that there is a correlation between the parameters, there is a linear functional dependence between them. An empirical dependence of d=1100.7712·T-0.3328 with a high degree of correlation (r = - 0.943) was established between the thickness and the corresponding transmittance coefficients of gold films for λ=532 nm. With this relative empirical error of thickness determination does not exceed 3%. The dependence of the maximum transmission spectrum Tλmax of nanosized gold films on the thickness of these films was experimentally established. At this step, the thickness determination did not exceed 1 Ǻ. The research data show the prospects of using the monochromatic photometric method to determine the thickness of plasma-carrying nanoscale layers.
Practical Approach to Care Kit: innovación para la clínica de enfermería en el manejo del VIH
Authors: Celuppi Ianka Cristina , Meirelles Betina Hörner Schlindwein , Costa Veridiana Tavares , Pires Denise Elvira Pires de
Published: February 2023

Resumen Objetivo: analizar el uso del Practical Approach to Care Kit como tecnología adoptada en la práctica clínica de los enfermeros en el manejo del VIH en la Atención Primaria de la Salud. Método: investigación exploratoria y descriptiva, basada en el marco metodológico de la Teoría Fundamentada en los Datos Constructivistas. La definición de los participantes fue realizada por muestreo inicial, con 12 enfermeros, y muestreo teórico, con cinco gestores, fueron 17 participantes en total. Los datos fueron recolectados a través de entrevistas intensivas y análisis de documentos, y fueron analizados en dos etapas: 1) codificación inicial; y 2) codificación enfocada. Resultados: los profesionales identificaron el Practical Approach to Care Kit como una innovación tecnológica que contribuyó a la expansión de la práctica clínica y al empoderamiento de los enfermeros en el manejo clínico de la infección por VIH. También destacaron su importancia como herramienta para orientar las diferentes responsabilidades y obligaciones en la distribución de la atención de los pacientes, contribuyendo a la prestación de prácticas basadas en evidencia. Conclusión: el Practical Approach to Care Kit es una innovación tecnológica que ha transformado la práctica clínica de los enfermeros en el manejo del VIH, ampliando su radio de acción para la realización del diagnóstico, evaluación del estado de salud y asesoramiento, evaluación de la adherencia al tratamiento, efectos adversos y prescripción de exámenes, medicamentos e inmunobiológicos.
Practical Approach to Care Kit: Innovation for nurses’ clinical practice in HIV management
Authors: Celuppi Ianka Cristina , Meirelles Betina Hörner Schlindwein , Costa Veridiana Tavares , Pires Denise Elvira Pires de
Published: February 2023

Abstract Objective: to analyze the use of the Practical Approach to Care Kit as a technology adopted in nurses’ clinical practice for HIV management in Primary Health Care. Method: an exploratory and descriptive research study anchored in the methodological framework of the Constructivist Grounded Theory. The participants were defined through initial sampling, with 12 nurses, and theoretical sampling, with five managers, totaling 17 participants. The data were collected by means of intensive interviews and documentary analysis, and they were analyzed in two stages: 1) Initial coding; and 2) Focused coding. Results: the professionals identified the Practical Approach to Care Kit as a technological innovation that contributed to expanding the clinical practice and to empowering nurses in the clinical management of HIV infection. They also highlighted its importance as a tool for guiding the different responsibilities and duties while sharing care, contributing to the provision of evidence-based practices. Conclusion: The Practical Approach to Care Kit is a technological innovation that has transformed nurses’ clinical practice in HIV management, expanding their scope of activities in carrying out the diagnosis, assessing the health condition and counseling, evaluating adherence to the treatment, adverse effects and prescription of exams, medications, and immunobiological.
Evaluación serológica y vacuna para la hepatitis B entre Agentes Comunitarios de Salud
Authors: Amaral Tauana de Souza , Alves Clery Mariano da Silva , Rezende Fabiana Ribeiro , Caetano Karlla Antonieta Amorim , Tipple Anaclara Ferreira Veiga
Published: February 2023

Resumen Objetivo: identificar la situación de la vacunación y serología contra la hepatitis B entre agentes comunitarios de la salud, vacunar contra el virus de la hepatitis B y evaluar la respuesta inmunológica de los agentes susceptibles. Método: fase I, estudio transversal y descriptivo, entre agentes comunitarios de la salud de una capital de la región centro oeste, por medio de cuestionario autoadministrado, verificación del carné de vacunación y extracción de sangre para comprobar los marcadores serológicos para la hepatitis B. Fase II, estudio de cohorte realizado en trabajadores vacunados no inmunes e identificados en la Fase I; estos recibieron una dosis de la vacuna (dosis de desafío) y realizaron el test serológico. Resultados: participaron del estudio 109 agentes. La mayoría tenía registro de vacunación (97; 89,0%) y de cobertura de vacunación (75; 77,3%); el marcador anti-HBs (Anticuerpos contra el virus de la hepatitis B) aislado fue detectado en 78 (71,6%) de los agentes. La prevalencia de exposición al virus de la hepatitis B fue de 8,2%. De los diez agentes vacunados no inmunes, después de la dosis desafío, uno permaneció susceptible. Conclusión: a pesar de que la mayoría de los trabajadores estaban vacunados y presentaron respuesta inmunológica para la hepatitis B, la susceptibilidad, después de la dosis desafío, fue identificada. Por tanto, es necesario que exista un programa de vigilancia de la situación de vacunación y estado serológico para este virus, para promover la seguridad de estos trabajadores.
Formación profesional del técnico en enfermería en seguridad del paciente: estudio mixto
Authors: Rocha Ruth Cardoso , Avelino Fernanda Valéria Silva Dantas , Borges José Wicto Pereira , Araújo Agostinho Antônio Cruz , Bezerra Maria Augusta Rocha , Nunes Benevina Maria Vilar Teixeira
Published: February 2023

Resumen Objetivo: analizar la formación de los técnicos en enfermería en seguridad del paciente. Método: estudio de método mixto paralelo convergente, en el que los elementos cualitativos y cuantitativos fueron implementados simultáneamente y considerados con el mismo nivel de prioridad, realizado en tres escuelas técnicas vinculadas a una institución pública federal en el Nordeste brasileño. En el estudio cualitativo se realizó una entrevista semiestructurada a 24 profesores y se aplicó el análisis temático. En el estudio cuantitativo, survey, se utilizó un instrumento para detectar términos sobre seguridad del paciente con 84 estudiantes. Para la interpretación general de los datos se realizó la combinación de los resultados y se tomó como base la Guía Curricular de Seguridad del Paciente. Resultados: surgieron dos categorías temáticas: Comprensión de los docentes sobre la seguridad del paciente en la formación de técnicos en enfermería e Implementación y proyección de la enseñanza de la seguridad del paciente en la formación de técnicos en enfermería. En el estudio cuantitativo, en los 46 términos indicadores, predominó la identificación de términos en el contexto teórico-práctico, en las carreras A y C, con un total de 36 (78,3%) y 25 (54,3%), respectivamente. En la carrera B se destacó la enseñanza teórica, con 26 términos (56,5%). Conclusión: la formación profesional de los estudiantes de la carrera de técnico en enfermería tiene un enfoque técnico y no considera de forma integral los temas que tienen que ver con la seguridad del paciente en el proceso de enseñanza-aprendizaje, por lo que es un desafío para las instituciones formadoras y para los docentes.
Profile and characteristics of violence against older adults during the COVID-19 pandemic
Authors: Ranzani Camila de Morais , Silva Sara Cirillo , Hino Paula , Taminato Mônica , Okuno Meiry Fernanda Pinto , Fernandes Hugo
Published: February 2023

Abstract Objective: to identify the sociodemographic profile and the characteristics of interpersonal violence against older adults during the first year of the COVID-19 pandemic in a capital city from the Brazilian Southeast region. Method: a descriptive and exploratory research study with a cross-sectional design based on the notifications of suspected or confirmed cases of violence against older adults between March 2020 and March 2021. A univariate statistical analysis and Fisher’s exact test (p<0.05) were performed. Results: a total of 2,681 notifications were recorded during the period. The main victims were individuals aged between 60 and 64 years old, female, white-skinned and with low schooling levels. The instances of violence were more frequent in the victims’ homes. Physical and psychological violence predominated, through physical force/beatings and threats, respectively. Most of the aggressors were male, younger than the victims and generally their children or intimate partners. The aggressions were perpetrated more than once and were driven by generational conflicts. There was low referral to entities for the protection of older adults. Conclusion: the sociodemographic profile found evidences vulnerable victims, subjected to many types of violence, and at a potential risk against their overall health.
Application of nano-antibiotics in the diagnosis and treatment of infectious diseases
Authors: Al-Awsi G. R. L. , Alameri A. A. , Al-Dhalimy A. M. B. , Gabr G. A. , Kianfar E.
Published: February 2023

Abstract Infectious diseases are the leading cause of death worldwide. Thus, nanotechnology provides an excellent opportunity to treat drug-resistant microbial infections. Numerous antibiotics have been used to inhibit the growth and kill of microbes, but the development of resistance and the emergence of side effects have severely limited the use of these agents. Due to the development of the nanotechnology, nanoparticles are widely used as antimicrobials. Silver and chitosan nanoparticles have antifungal, antiviral and antibacterial properties, and many studies confirm the antifungal properties of silver nanoparticles. Nowadays, the use of nanoparticles in the diagnosis and treatment of infectious diseases has developed due to less side effects and also the help of these particles in effective drug delivery to the target tissue. Liposomes are also used as carriers of drug delivery, genes, and modeling of cell membranes in both animals and humans. The ability of these liposomes to encapsulate large amounts of drugs, minimize unwanted side effects, high effectiveness and low toxicity has attracted the interest of researchers. This review article examines recent efforts by researchers to identify and treat infectious diseases using antimicrobial nanoparticles and drug nano-carriers.
Comparison of phosphorus-based extractants on manganese separation from citrate leach solutions for recycling of lithium-ion batteries
Authors: Punt Tiaan , Luckay Robert C. , Akdogan Guven , Bradshaw Steven M. , Van Wyk A. Petrie
Published: January 2023

The performance requirements of modern lithium-ion batteries (LIBs) necessitate the use of a number of scarce and strategically sensitive metals such as lithium and cobalt. Recycling end-of-life LIBs reduces the demand on the primary sources of these metals and helps reduce the environmental impact of LIB waste. Citric acid has proven to be an effective environmentally friendly and sustainable lixiviant; however, the formation of metal citrate complexes complicates subsequent metal separation processes such as solvent extraction. This study enhances the understanding of LIB metal separation from citric acid media by comparing the metal separation performance of phosphorus-based liquid-liquid extractants from a citric acid leach. The optimum Mn(II) extraction pH decreases as the extractant’s phosphorus oxidation state increases from phosphinic to phosphonic to phosphoric, due to the oxygen atoms that surround the central phosphorus atom. The maximum Mn(II) separation with Cyanex 272, PC-88A, and D2EHPA was observed at pHs of 6, 3, and 3, respectively. D2EHPA further provided the best separation of Mn(II) over Al, Co, Li, and Ni with separation factors of 137, 191, 118, and 601, respectively. No research is currently available on the metal separation performance of phosphonic (PC-88A) or phosphinic (Cyanex 272) organic extractants from citric acid media.Significance:

This study is the first to investigate the use of phosphonic and phosphinic extractants for metal separation from citric acid leach solutions, towards using citric acid as an environmentally friendly lixiviant.
The phosphoric extractant, D2EHPA, enabled successful and sequential separation and extraction of aluminium, manganese and lithium, making the process technologically feasible and attractive.
Current situation and future prognosis of health, safety and environment risk assessment of nanomaterials in South Africa
Authors: Gulumian Mary , Thwala Melusi , Makhoba Xolani , Wepener Victor
Published: January 2023

The commercialisation and everyday use of nanomaterials and nanomaterial-enabled products (NEPs) is rising year-on-year. Responsible development of nanotechnology includes understanding their potential implications on health, safety, and the environment (HSE). The health risk assessment of nanomaterials has therefore become one of the major activities of international agencies including the Organisation for Economic Co-operation and Development and the Environmental Protection Agency for protection of human health and the environment. Nationally, with the foresight and the leadership of the Department of Science and Innovation, a HSE programme was initiated to establish the necessary infrastructure to conduct the tests in the hazard identification and exposure assessment that are needed in the risk assessment of nanomaterials synthesised as well as NEPs available in South Africa. Here we present the advances that have been made in elucidating the different facets that are required when undertaking risk assessments of nanomaterials, i.e. physicochemical characterisation, hazard identification, exposure assessment and effects assessment. These facets are increasingly being considered throughout the nanomaterials present in the life cycles of NEPs. South Africa's research contribution to an international understanding of HSE risks of nanomaterials is highlighted and the future direction to generate the necessary information for effective risk communication and management is provided. This will assist in ensuring safer innovation of nanotechnology in South Africa and support the export of locally manufactured nanomaterials as per international requirements.Significance:

Significant contributions of South Africa to the nanomaterial HSE knowledge base are highlighted.
Development of standardised testing methodologies in nanomaterial HSE and protection of human and ecological health through risk assessment of nanomaterials are discussed.
This paper contributes to ensuring safer innovation of nanotechnology in South Africa.
Science communication: The link to enable enquiry-based learning in under-resourced schools
Authors: Nemadziva Blessing , Sexton Steven , Cole Catherine
Published: January 2023

Improving skills in STEM disciplines has been identified as essential in meeting South Africa’s economic growth targets. Despite this, learner uptake and completion rates within these subjects is currently well below international standards. We therefore examined key stages within the science education system to identify factors contributing to the low throughput in science education. We reviewed how national science policy changes have impacted the curriculum and teaching practices across different education establishments and socio-economic groups. We highlight that 80% of public schools have a lack of resources for practical learning, making it difficult for teachers to implement enquiry-based teaching methods. We explored strategies for effective engagement with science from the science communication literature and present recommendations to improve learner engagement with science in under-resourced school settings. Whilst education reform is needed at a national scale, we make a case for using science communication practices in science classes as a more immediate solution to generate greater interest and understanding, and encourage learners to pursue careers in science.Significance:

We examined key challenges in the science education and training pipeline in South Africa and recommend the use of science communication practices to design resources to enhance science teaching and learning in under-resourced schools. 
Exploring ways of integrating informal learning tools into schools could be a simple approach to improve science teaching and learning in developing countries such as South Africa where infrastructural deficit poses a longer-term barrier to learning.
Deep learning for photovoltaic defect detection using variational autoencoders
Authors: Westraadt Edward J. , Brettenny Warren J. , Clohessy Chantelle M.
Published: January 2023

Faults arising in photovoltaic (PV) systems can result in major energy loss, system shutdowns, financial loss and safety breaches. It is thus crucial to detect and identify faults to improve the efficiency, reliability, and safety of PV systems. The detection of faults in large PV installations can be a tedious and time consuming undertaking, particularly in large-scale installations. This detection and classification of faults can be achieved using thermal images; use of computer vision can simplify and speed up the fault detection and classification process. However, a challenge often faced in computer vision tasks is the lack of sufficient data to train these models effectively. We propose the use of variational autoencoders (VAEs) as a method to artificially expand the data set in order to improve the classification task in this context. Three convolutional neural network (CNN) architectures – InceptionV3, ResNet50 and Xception – were used for the classification of the images. Our results provide evidence that CNN models can effectively detect and classify PV faults from thermal images and that VAEs provide a viable option in this application, to improve model accuracy when training data are limited.Significance:

Faults in PV systems can be labour and time consuming to detect and classify. This process can be automated by using computer vision and thermal images.
CNN models (InceptionV3, ResNet50 and Xception) are effective in the detection and classification of PV faults from thermal images.
Small data sets are a common barrier to entry for computer vision assessments. VAEs provide an effective method to artificially expand a limited data set to allow for the successful use of CNN models.
The expansion of training data using VAEs for CNN models can improve the prediction accuracy in these models.
COVID-19 and common mental disorders among university students in South Africa
Authors: Bantjes Jason , Swanevelder Sonja , Jordaan Esme , Sampson Nancy A. , Petukhova Maria V. , Lochner Christine , Stein Dan J. , Kessler Ronald C.
Published: January 2023

COVID-19 has had far-reaching economic, social and health consequences, with vulnerable groups disproportionally affected. Even before the COVID-19 pandemic, concern was expressed about university students’ mental health, with global data suggesting students are more vulnerable than the general population to mental disorders. Yet, it is unclear what the pandemic’s impact has been on the mental health of students in South Africa. We examined the impact of COVID-19 on first-year students at two universities in South Africa by analysing changes in the prevalence and age-of-onset of three common mental disorders (namely major depressive episode, generalised anxiety disorder, and suicidal ideation) before and during the pandemic, and comparing these to changes between 2015 and 2017. Our analysis of cross-sectional survey data collected in 2015, 2017 and 2020 shows no clear or consistent pattern of increases in prevalence of common mental disorders following the start of the pandemic. Lifetime prevalence rates of common mental disorders among students have been steadily increasing since 2015, and where increases before and during COVID-19 were observed, they are not consistently larger than increases between 2015 and 2020. No significant changes were observed in the 12-month prevalence of common mental disorders before and during COVID-19, except for an increase in prevalence of depression at one institution, and a decrease in suicidal ideation at the other. Findings suggest that in the context of ongoing adversity and disruptions on South African university campuses in recent years, COVID-19 may be just one more stressor local students face and that its impact on student mental health may not have been as marked in South Africa compared to other regions.Significance:

This study is the first to explore COVID-19’s impact on university students’ mental health in South Africa, using data collected before and during the pandemic.
High rates of psychopathology confirm the need for sustainable campus-based interventions to support student well-being.
Rates of mental disorders among students have been increasing since 2015, and increases observed in 2020 were no larger than those observed in prior years.
In the context of disruptions on university campuses in recent years, COVID-19 is just one more stressor for students, and its impact may not have been as marked in South Africa compared to other regions.