bluuebunny/crossref_metadata_2025 huggingface dataset:
PURWARUPA SISTEM PEMANTAUAN POLUSI UDARA DI RUANG TERTUTUP MENGGUNAKAN PLATFORM THINGSPEAK
Authors: Exaudi Kemahyanto , Setiawan Nabillah Selva , Prasetyo Aditya P P , Passarella Rossi , Ubaya Huda , Sari Purwita , Zulfahmi Rido , Mediswati Roswitha Yemima Tiur
Published: January 2024

Smoking is an act of negligence that a person commits intentionally and causes personal harm. The habit of smoking has spread to children and adolescents. One of the health impacts of smoking is the smoke that is released. Therefore, cigarette smoke is categorized as one of the causes of air pollution. A bad habit that smokers do is smoking in a closed room with minimal ventilation. As a result, the air in the room is contaminated by harmful substances from cigarette smoke. This study aims to monitor the quality of air exposed to cigarette smoke in a prototype closed room and measure the effectiveness of sansevieria plants placed in the room to absorb cigarette smoke in real-time. Air quality is displayed in graphical form using the Thingspeak Platform. The stages carried out in this research are air quality detected using an MQ-7 sensor integrated with the MCU8266 WiFi Node, converting sensor data into smoke density values in units of PPM (parts per million), displaying air PPM graphs in real-time and displaying the absorption ability of sansevieria against air contaminated with cigarette smoke. The results prove that one pot of sansevieria plants (5 leaves) placed in a prototype room with a size of 70cm x 30cm x 45cm can absorb cigarette smoke within 1 hour 39 minutes. While for two pots of sansevieria plants (10 leaves), it takes 1 hour and 11 minutes. Visualization of the absorption graph and normalization of air in the room can also be monitored in real-time through the Thingspeak platform based on the smoke density value against time.
PERANCANGAN GIRDER PADA FLEKSIBEL GANRTY CRANE KAPASITAS 1 TON
Authors: Tritjahjono Rachmad Imbang , Ramadhan Ramadhan , Muliastri Destri , Sukardi Casiman , Gemilang Yun
Published: January 2024

Lifting and transporting equipment is one of the keys to carrying out work in the manufacturing and construction industries. Due to limited access, various obstacles must be overcome in some working areas. A ganrty crane is an alternative lifting equipment that has high flexibility. This article reports the research results on the girder’s main components. This component gets direct contact with loading when lifting and rigging work is carried out. This research method was conducted by comparing manual calculation models and CAE using the Solidworkss Simulation software. From these two methods, this study yielded 23.091 and 25.54MPa for manual calculations and the finite element method, respectively. Furthermore, in the finite element method with direct contact loading, a stress of 40.52MPa is obtained. From the three stress calculations, it can be concluded that the safety factor has exceeded the requirements set out in the standard. Furthermore, utilizing the Goodman model, mitigating the possibility of fatigue failure also indicates a safe condition. Based on recent research reports, a potential self-healing is not yet possible to be recognized well especially for metals having a grain size of micron.
Integrating pyArchInit and BraDypUS for field and academic archaeological research
Authors: Guarino Giuseppe , Rosati Paolo
Published: January 2024

This article presents an attempt to integrate into a single workflow two important tools for the management of archaeological data: pyArchInit and BraDypUS. Although each system has its proper applications and capabilities, their combined use could have brought several advantages. However, it is worth noting that the work currently has some structural limitations that can be resolved only by the modification of the source code. This work summarises and reports on the current methodologies (as of 2021) for operating on both desktop and web platforms simultaneously using specific tools.
From micro-regional to intra-site analysis: the GIS of the Italian Archaeological Expedition in the Erbil Plain (Kurdistan Region of Iraq)
Authors: Oselini Valentina , Campeggi Michael , Forti Luca , Ginoli Elisa , Pezzotta Andrea , Vacca Agnese , Peyronel Luca
Published: January 2024

The Italian Archaeological Expedition in the Erbil Plain (MAIPE https://orienteantico.unimi.it/it/maipe/) of the University of Milan is experimenting with a GIS project based on the QGIS system. The project aims to combine data from survey, excavation, and geomorphological investigations carried out at the two sites of Helawa and Aliawa and their surrounding landscape. The MAIPE GIS is intended as a valuable tool for predictive, distributive and cross-data analyses considering the complex diachronic development of the area and the results of paleoenvironmental studies at a micro-regional and intra- site scale
Using Programming Environments for Academic Research and Writing
Authors: Lemmer-Webber Morgan
Published: January 2024

Developer tools, such as code editors, markup languages, and revision control have a greater range of functions than word processors. As a scholar engaged in both Digital Humanities and the FOSS community, I have become increasingly interested in how these tools can be applied to research workflows. I wrote my dissertation in the editor Dr. Racket using Scribble, allowing me to incorporate code directly into my document. In this paper, I discuss the benefits and pitfalls of this decision.
Mitophagy in Alzheimer’s Disease: A Bibliometric Analysis from 2007 to 2022
Authors: Wang Hongqi , Yan Xiaodong , Zhang Yiming , Wang Peifu , Li Jilai , Zhang Xia
Published: January 2024

Background:

The investigation of mitophagy in Alzheimer’s disease (AD) remains relatively underexplored in bibliometric analysis.

Objective:

To delve into the progress of mitophagy, offering a comprehensive overview of research trends and frontiers for researchers.

Methods:

Basic bibliometric information, targets, and target-drug-clinical trial-disease extracted from publications identified in the Web of Science Core Collection from 2007 to 2022 were assessed using bibliometric software.

Results:

The study encompassed 5,146 publications, displaying a consistent 16-year upward trajectory. The United States emerged as the foremost contributor in publications, with the Journal of Alzheimer’ s Disease being the most prolific journal. P. Hemachandra Reddy, George Perry, and Xiongwei Zhu are the top 3 most prolific authors. PINK1 and Parkin exhibited an upward trend in the last 6 years. Keywords (e.g., insulin, aging, epilepsy, tauopathy, and mitochondrial quality control) have recently emerged as focal points of interest within the past 3 years. “Mitochondrial dysfunction” is among the top terms in disease clustering. The top 10 drugs/molecules (e.g., curcumin, insulin, and melatonin) were summarized, accompanied by their clinical trials and related targets.

Conclusions:

This study presents a comprehensive overview of the mitophagy research landscape in AD over the past 16 years, underscoring mitophagy as an emerging molecular mechanism and a crucial focal point for potential drug in AD. This study pioneers the inclusion of targets and their correlations with drugs, clinical trials, and diseases in bibliometric analysis, providing valuable insights and inspiration for scholars and readers of JADR interested in understanding the potential mechanisms and clinical trials in AD.
Discovering Process Models with Long-Term Dependencies while Providing Guarantees and Filtering Infrequent Behavior Patterns
Authors: Mannel Lisa L. , van der Aalst Wil M. P.
Published: January 2024

In process discovery, the goal is to find, for a given event log, the model describing the underlying process. While process models can be represented in a variety of ways, Petri nets form a theoretically well-explored description language and are therefore often used. In this paper, we extend the eST-Miner process discovery algorithm. The eST-Miner computes a set of Petri net places which are considered to be fitting with respect to a certain fraction of the behavior described by the given event log as indicated by a given noise threshold. It evaluates all possible candidate places using token-based replay. The set of replayable traces is determined for each place in isolation, i.e., these sets do not need to be consistent. This allows the algorithm to abstract from infrequent behavioral patterns occurring only in some traces. However, when combining places into a Petri net by connecting them to the corresponding uniquely labeled transitions, the resulting net can replay exactly those traces from the event log that are allowed by the combination of all inserted places. Thus, inserting places one-by-one without considering their combined effect may result in deadlocks and low fitness of the Petri net. In this paper, we explore adaptions of the eST-Miner, that aim to select a subset of places such that the resulting Petri net guarantees a definable minimal fitness while maintaining high precision with respect to the input event log. Furthermore, current place evaluation techniques tend to block the execution of infrequent activity labels. Thus, a refined place fitness metric is introduced and thoroughly investigated. In our experiments we use real and artificial event logs to evaluate and compare the impact of the various place selection strategies and place fitness evaluation metrics on the returned Petri net.
Rehabilitative effects of electrical stimulation on gait performance in stroke patients: A systematic review with meta-analysis
Authors: Hwang Sujin , Song Chiang-Soon
Published: January 2024

BACKGROUND: Electrical stimulation techniques are widely utilized for rehabilitation management in individuals with stroke patients. OBJECTIVES: This review aims to summarize the rehabilitative effects of electrical stimulation therapy on gait performance in stroke patients. METHODS: This review included randomized controlled trials (RCT) investigating the therapeutic effects of electrical stimulation in stroke patients throughout five databases. This review qualitatively synthesized 20 studies and quantitatively analyzed 11 RCTs. RESULTS: Functional electrical stimulation (FES) was the most commonly used electrical stimulation type to improve postural stability and gait performance in stroke patients. The clinical measurement tools commonly used in the three studies to assess the therapeutic effects of FES were Berg balance scale (BBS), 10-meter walk test (10MWT), 6-minute walk test (6mWT), and gait velocity. The BBS score and gait velocity had positive effects in the FES group compared with the control group, but the 10MWT and 6mWT showed the same effects between the two groups. The heterogeneity of BBS scores was also high. CONCLUSION: The results of this review suggest that electrical stimulation shows little evidence of postural stability and gait performance in stroke patients, although some electrical stimulations showed positive effects on postural stability and gait performance.
Navigating the Landscape of AI in Reading: Unveiling Opportunities and Considerations
Authors: Belavadi Dr Nikhil
Published: January 2024

The article delves into the complex relationship between reading and artificial intelligence, examining the several ways in which AI has affected our reading behaviours. It explores the benefits that AI offers, from virtual reading tutors to individualized learning platforms. But amid the promises, there are issues like short-form content and distractions. The paper stresses the significance of a careful and balanced approach to incorporating technology in education while offering ideas for using AI to improve students' reading abilities.
Ethological and Psychological Aspects of Pantomimic Self-Harming Behavior
Authors: Goncharenko Elena , Mikvabiya Zurab , Taisaeva Svetlana , Argun Sofia , Murzova Olga , Anna Jokua , Grishina Anna
Published: January 2024

In the present work, self-injurious behavior of humans and higher animals is considered from the ethological approach. In clinical work, the analysis of patho-psychological disorders and disorders from the point of view of ethological psychiatry (psychology) allows us to understand the nature, pathogenesis and mechanisms of behavioral patterns and pantomimics in patients with borderline and psychiatric disorders. Self-traumatization can be observed in epilepsy, autism, mental retardation, and in accentuated and neurotic adolescents. According to the author's team, body and skin damage is a manifestation of instinctual response. Physical autoaggression satisfies the realization of aggressive instinct, is supported by opioid pleasure from pain and is realized at limitation of direct reaction to negative stimulus. The authors conducted a comparative analysis of the pantomimics of physical autoaggression (self-injury) of 15 adolescents with psychological traumas, 15 children with mental dysontogenesis and 12 monkeys (javan macaques and rhesus macaques). Results of the study showed that experimental primates redirected aggression to their own bodies and limbs in the face of an attack motivation obstacle. Adolescents, in response to the stressor, insected their skin with sharp and stabbing objects. Children with psycho-verbal disorders illustrated primatological forms of self-injury in response to a limiting and negative stimulus. The revealed pantomimic acts of physical autoaggression in experimental monkeys, children with mental developmental disorders, and adolescents with psychotraumatic experience show the commonality and species specificity of the nonverbal pattern of self-injury. In humans and primates, homologs of autoaggressive patterns in pantomimic production are found in nonverbal production. The study may be useful to psychiatrists, neurologists, psychologists, and psychotherapists.
Masseteric nerve vs. hypoglossal nerve: choice of donor nerve in the reanimation of short-term facial palsy
Authors: Henares A. , Vicente-Ruiz M. , Hontanilla B.
Published: January 2024

A number of techniques have been developed to repair the aesthetic and functional defects in patients affected by facial paralysis. The choice of technique in the dynamic rehabilitation of the smile is influenced by factors such as the patient’s age, facial phenotype, time of evolution or the surgeon’s preferences, among others. When a nerve transfer or the neurotization of a muscle transplant are performed, the dilemma arises of selecting the ideal donor nerve. The hypoglossal and masseteric nerves are usually used for this type of procedure. Although the hypoglossal nerve can achieve effective facial movements, mass facial movements and synkinesis have also been described. Depending on the level of nerve coaptation, these side effects could be avoided to some extent. Moreover, the recovery of spontaneous facial smiling using the hypoglossal nerve is almost anecdotal. On the other hand, the masseteric nerve allows neurotization of the facial nerve without the use of nerve grafting, provides a high axonal load, faster recovery and, above all, a higher percentage of spontaneous smile, especially in women. Therefore, the masseteric nerve would be the donor nerve of choice in the rehabilitation of short-term facial paralysis.
Control of technological parameters in the process of ribbed panel forging: use of measuring equipment and mathematical modeling methods
Authors: Zharov M. V. , Preobrazhenskii E. V.
Published: January 2024

The article discusses the control of technological parameters for the process of isothermal forging of cross-ribbed panels. To ensure defect-free manufacturing of panels, strict adherence to the temperature and rate conditions is required. However, due to errors and external disturbances, the measuring equipment does not often provide reliable information. In addition, the temperature of the metal in the deformation zone can only be estimated indirectly. Therefore, by analogy with the Kalman filter, it is proposed to combine data from sensors and the results calculated using the finite element method. For this purpose, the accuracy and speed of calculation of the finite element model were studied in four popular specialized software products: DeForm, QForm, Forge NxT, Simufact Forming. Comparison of the results of the analysis made it possible to confirm the high degree of reliability of modeling and the potential possibility of controlling technological parameters for the production of defect-free panels by the suggested way. It is shown that the finite element method in the two-dimensional formulation of the problem provides an acceptable calculation speed for monitoring the progress of operations in real time. The obtained results are relevant for metallurgical enterprises for which there are increased requirements for compliance with the range of permissible changes in technological parameters during production processes.
Intelligent intertraverse dynamograph of the mesdoza of sucker-rod deep-pumping units
Authors: Rzayev A. H. , Aliyev Ya. G. , Rezvan M. H.
Published: January 2024

Rod downhole pumping units widely used in oil production are described. It is shown that oil production depends on the mode of operation of these units, which is selected based on the results of the analysis of closed dynamometer charts. Dynamograms describe the load on the suspension depending on the course of the polished rod of the installation, the quality of the construction of the dynamograms is decisive for diagnosing the technical condition of the installation. The trends in the development of existing dynamometer systems and methods for diagnosing the state of a sucker rod pumping unit are analyzed. One of the ways to create an intelligent intertraverse mesdoza dynamograph based on the mesdoza of a pocket dynamograph using modern pressure, acceleration, temperature sensors, STM32 controllers, a graphic liquid crystal display with an I2C interface, radio communication protocols and digital technologies for processing periodic sensor signals is presented. Based on the analysis of existing dynamometer systems and force and stroke sensors installed in various places of the installation design, and taking into account modern advances in technology and technologies for analyzing the noise of the measured signals, the possibility of developing an intelligent stationary dynamograph is shown. This dynamograph must provide early diagnostics of the technical condition of the installation and meet the following criteria: low cost; ease of installation; high sensitivity, reliability, flexibility and accuracy. A block diagram of an intelligent intertraverse dynamograph of the mesdoza of a sucker-rod deep pumping unit, based on the mesdoza of a pocket dynamograph, is presented. The proposed intelligent intertraverse dynamograph will be useful for early diagnostics of the technical condition of downhole pumps and tubing pipes connecting them with ground equipment, which will ultimately help to improve the reliability of oil production equipment. The proposed intelligent intertraverse dynamograph can also be used in other areas of technology where there is a need to measure force.
A measure of differences in speech signals by the voice timbre
Authors: Savchenko V. V.
Published: January 2024

This research relates to the field of speech technologies, where the key problem is the optimization of speech signal processing under conditions of a priori uncertainty of its fine structure. The task of automatic (objective) analysis of voice timbre using a speech signal of finite duration is considered. It is proposed to use a universal information-theoretic approach to solve it. Based on the Kullback-Leibler divergence, an expression is obtained for the asymptotically optimal decision statistic for distinguishing speech signals by voice timbre. Pointed to an acute problem in its practical implementation, namely: synchronization of the sequence of observations with the main tone of speech signals. To overcome the described problem, an objective measure of timbre differences in speech signals is proposed in terms of the acoustic theory of speech production and its model of the speaker’s vocal tract of the “acoustic trumpet” type. The possibilities of practical implementation of a new measure based on an adaptive recursive are considered. A full-scale experiment was set up and carried out. According to its results, two main properties of the proposed measure were confirmed: high sensitivity to differences in speech signals in terms of voice timbre and, at the same time, invariance with respect to the pitch frequency. The results obtained can be used in the design and research of digital speech processing systems tuned to the speaker’s voice, for example, digital speech transmission systems, biometric, biomedical systems, etc.
Legislative basis for assurance of measurement uniformity
Authors: Denisenko S. A. , Isaev L. K.
Published: January 2024

An overview of the legal framework of metrology at the international level, in particular, the activities of the intergovernmental International Organization of Legal Metrology, is given. The establishment of the International Organization of Legal Metrology has had an impact on the consolidation of the regulatory framework for metrology at the regional level, especially in the European Union. The reliability, comparability and traceability of measurement results are ensured by international regulatory documents developed by countries in the field of activity of seven international organizations. For international recognition of measurement and test results of any country. There is a need for a system of normative instruments that ensure international law. Strategically, it is necessary to create a legal framework so that it is possible to move from regional politics to global politics. The role of legal metrology at the regional level and the formation of the legislative framework of fundamental metrology in the world are described. The article presents a database of basic documents for solving scientific problems of ensuring the uniformity of measurements at the international level and the main milestones in the history of the formation of the legal framework of the measurement system in Russia for two centuries. The creation of the metrological service of the USSR, and then the state system for ensuring the uniformity of measurements determined new approaches to improving legislation in the field of metrology. Harmonization of the language of measurements and approaches to solving the problems of metrology will ensure the uniformity of measurements not only in individual countries and regions, but also on a global scale.
Robust parameter design of the measurement procedure for determining the chemical composition of copper alloys by X-ray fluorescence
Authors: Mitrofanova S. A. , Muravyeva I. V.
Published: January 2024

A brief overview of contemporary methods for determining the chemical composition of copper alloys and the analytical control methods used is given. It has been shown that to obtain reliable and comparable results of measuring the mass fractions of copper alloys elements in wide ranges of values, the most suitable procedures are based on the X-ray fluorescence method, implemented using portable X-ray fluorescence spectrometers. In order to select the optimal values of the influencing quantities when determining the chemical composition of copper alloys, a robust parameter design of a quantitative chemical analysis procedure was carried out on the X-50 Mobile X-ray fluorescence spectrometer. The use of robust parameter design, as opposed to conducting a full factorial experiment when developing a measurement procedure, makes it possible to optimize measurement conditions and obtain results of the required accuracy with a limited number of experiments and a maximum number of control factors. An example of drawing up an experimental plan for the parameter design of this procedure is given and a statistical analysis of the measurement results is carried out. The optimal measurement conditions (influencing quantities) were analyzed and selected, under which the minimum error in the results of measuring the mass fraction of elements is ensured. The selection of optimal values of the influencing quantities based on the results of robust parameter design of the quantitative chemical analysis procedure made it possible to increase the accuracy of the results of determining the chemical composition of copper alloys and, as a consequence, the reliability of the results of product quality control at relatively low costs for its implementation. This approach can be recommended to analytical laboratories developing procedures of quantitative chemical analysis for metallurgical industry enterprises.
Inf uence of the variable geometry of the diverter nozzle on the metrological characteristics of a calibration unit with weighing devices
Authors: Korneev A. A. , Shchelchkov A. V. , Korneev R. A.
Published: January 2024

This article discusses the issues of improving the metrological characteristics, weight-dimensional and technical and economic indicators of calibration installations with weighing devices due to the introduction of a fl ow switch with a variable nozzle exit geometry into their design. It is assumed that the use of this design of the fl ow switch will solve the problem of fi lling the nozzle exit with water, reduce the dimensions of the hydraulic path, simplify the maintenance procedure, and reduce the cost of installations. A description of the design, principles of operation and a timing diagram of a fl ow switch with a variable nozzle exit geometry are presented. The local hydrodynamic characteristics of the water fl ow by a Pitot tube in the nozzle exit are studied with a change in its width in the mass fl ow rate range from 25 to 550 t/h. The optimal values of the nozzle cut width are experimentally determined depending on the value of the mass fl ow rate of the liquid, at which it is completely fi lled with liquid. A study of the metrological characteristics of a calibration installation with weighing devices, which includes a fl ow switch with a variable nozzle exit geometry, methods of indirect measurements and comparisons using a comparison standard in a wide range of liquid mass fl ow rates, has been carried out. The impact on the metrological characteristics of a calibration installation with weighing devices of the nozzle cut width in the investigated range of liquid fl ow is established. Graphical dependences of the expanded measurement uncertainty of the installation when reproducing the unit of liquid mass fl ow rate on the measurement time interval and on the mass fl ow rate of the liquid are presented. Based on the research results, the optimal values of the nozzle cut width and measurement time intervals were determined depending on the mass fl ow rates of the liquid when using a fl ow switch with a variable nozzle cut geometry. The expansion of the range of operation of weighing devices, which are part of the verifi cation installations with weighing devices, is justifi ed. According to the results of the research, the proposed design of the fl ow switch with a variable geometry of the nozzle exit is recommended for use in the design of new and modernization of installations for calibration with weight devices of fl ow switches.
Investigation of a strain-gauge dynamometer for measuring boundary layer friction force on the wind tunnel wall
Authors: Anokhina E. N. , Gorbushin A. R.
Published: January 2024

A one-component strain-gauge dynamometer with a measuring range of 0-0.33 N was developed and manufactured at the Central Aerohydrodynamic Institute to measure directly the unsteady friction force of the boundary layer on the wall of a wind tunnel at very high Reynolds numbers. The subject of this study is to investigate the static and dynamic characteristics of the dynamometer and its systematic errors. The effects of the temperature, longitudinal, normal, and side forces and position of the longitudinal force application were investigated during the calibration. A block was designed and manufactured to calibrate the dynamometer using the dead weights in a wind tunnel. The calibration was carried out in laboratory conditions to determine friction force in the block. The developed dynamometer is a dynamic system with its own natural frequency of oscillations. The correction for the dynamometer's own dynamics is suggested on the basis of the method developed earlier. To calculate the correction to dynamometer dynamics the mass of the metric part of the dynamometer, its natural frequency in the absence of damping and the damping coeffi cient were determined. The correction is verifi ed by experiment with application of a step force. Effect of static and dynamic temperature components on dynamometer readings is investigated. Corrections are proposed to eliminate the systematic errors due to the effect of temperature on the basis of the previously developed method. It is shown that the side force does not affect the dynamometer readings, while the effect of the normal force is 1.1 % of the main sensitivity coeffi cient. The effect of the static temperature component on the sensitivity coeffi cient of the dynamometer is 0.017 %/°C. The total measurement uncertainty of the friction force dynamometer is estimated – the standard deviation of the measurement results does not exceed 0.076 % of the measurement range and the relative standard deviation of the main sensitivity coeffi cient is 0.03 %. The standard deviation of measurement of the nonstationary friction force will not exceed 0.86 % of the range of the dynamometer in the presence of oscillations of the sensitive element at its natural frequency.
Infrared visibility and infrared visibility range: the practical signif cance and method for measuring
Authors: Khodunkov V. P.
Published: January 2024

New physical quantities are presented – infrared visibility and infrared visibility range. The relevance and demand for measurements of these quantities is shown. Their physical meaning is revealed, formula ratios for the calculation are given, and the practical signifi cance. The presented calculation ratios are obtained on the basis of the transformation of the real thermal portrait of the object into an equivalent thermal geometric model. It is shown that the numerical values of the infrared visibility index for various real objects can vary over a wide range: from zero for absolutely non-thermal contrast objects to values of several units for high-contrast objects, i.e. within 0.5–2.5. The ratio for the infrared visibility range is obtained in based on the Lambert-Bouguer-Beer law and Fechner's law, used in the theory of sensory sensitivity. A detailed description and procedure for measuring the indicated physical quantities is presented, examples are given, and the measurement uncertainty is estimated. The introduced values are aimed at ensuring the unity of the assessment of thermal protection of various man-made and biological objects and allow developing preventive measures for their thermal protection at the stage of commissioning.
State primary standard of units of mass (molar) fraction and mass (molar) concentration of components in liquid and solid substances and materials based on spectral methods GET 196-2023
Authors: Ivanov A. V. , Gryazskikh N. Yu. , Chugunova M. M. , Zyablikov D. N. , Zyablikova I. N. , Ermakovа Ya. I. , Polunina E. P. , Alenichev M. K. , Yushina A. A.
Published: January 2024

The necessity of the development of metrological support for measurements of the content of gas components in metals and alloys, trace impurities in various industrial facilities (metallurgical, medical, etc.) is analyzed. The needs of industries in the development of more sensitive measurement methods and techniques, standard samples of expanded nomenclature with a lower error (uncertainty) of the certifi ed characteristics than the error of the certifi ed characteristics existing today are studied day of standard samples of the approved type of composition. The standard samples being developed for use in the fi eld of state regulation should be traced to the primary standards of mass (molar) fraction and mass (molar) concentration: the State primary standard of units of mass (molar) fraction and mass (molar) concentration of components in liquid and solid substances and materials based on spectral methods GET 196-2023, the State primary standard of units mass (molar, atomic) fraction and mass (molar) concentration of components in liquid and solid substances and materials based on coulometry GET 176-2019, State primary standard of units of mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods GET 217-2018, State primary standard of units of mass (molar) fraction and and mass (molar) concentration of organic components in liquid and solid substances and materials based on liquid and gas chromatography-mass spectrometry with isotopic dilution and gravimetry GET 208-2019.

The need and ways of developing and creating a system of metrological support for Raman spectrometry in the Russian Federation, including in order to confi rm the traceability of units of quantities for quantitative Raman analysis, are analyzed. To solve these issues, the GET 196-2023 includes sulfur, carbon and hydrogen analyzers, an inductively coupled plasma mass spectrometer and a Raman complex. The composition and metrological characteristics of GET 196-2023 are presented. A draft state verifi cation scheme for measuring the mass (molar) fraction and mass (molar) concentration, as well as the fl uorescence of components in liquid and solid substances and materials based on spectral methods has been developed and presented. The draft of the state verifi cation scheme establishes the procedure and methods for transferring units of mass (molar) fraction of components (in absolute units), mass (molar) concentration of components (grams per cubic decimeter, mole per cubic decimeter) from GET 196-2023 to measuring instruments indicating the error and uncertainty of measurements. Also, with the help of secondary and working standards, relative units of fl uorescence are transmitted to measuring instruments.
State primary standard of units for electric current intensity conversion coeffi cients GET 152-2023
Authors: Akhmeev A. A. , Voronskaya E. V.
Published: January 2024

The metrological support of measuring current converters as the main elements intended for measuring a large electric current is considered. Brief historical information about the creation of the State primary standard of units for electric current intensity conversion coeffi cients is given. The composition and metrological characteristics of the State primary standard of units for electric current intensity conversion coeffi cients GET 152-2023 are presented. The equations of measurements and the results of the studies of two standard measuring installations created as part of the improvement of GET 152-2023 from 2019 to 2022 are given. It is shown that the range of reproducible rated primary currents of a sinusoidal current installation is 1–1000 A in the frequency range of 40–2500 Hz, and the range of reproducible rated primary currents of a high direct current installation is 1000–10000 A. The data on the state verifi cation scheme for measuring instruments of the electric current conversion coeffi cients are given. Comparisons with the participation of UNIIM as a pilot for the period from 2019 to the present are listed. The prospects of further improvement of the GET 152-2023 to expand the measurement and calibration capabilities of this fi eld of measurement in the Russian Federation are described. The results of the work are relevant for metrological support of measuring converters of large electric current used in power engineering and industry.
The role of UCH-L1 in some activities of nervous system
Authors:   Department of Biochemistry, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Kim Truong Huynh Thoa ,   Vietnam National University Ho Chi Minh City, Vietnam
Published: January 2024

Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) plays an important role in the ubiquitinproteasome system and distributes mostly in the brain. Previous studies showed that the mutation form or reduction of UCH-L1 related to neurodegenerative disorders such as Parkinson disease, Alzheimer disease and also involved to the oxidative stress. However the specific role of UCH-L1 on the activities of the nervous system has not yet well been understood. Among several models to study the role of UCH-L1, Drosophila melanogaster one showed several advantages particularly in the study of the neurodegeneration. To clarify the effects of UCH-L1 deficiency in neurons, we used Drosophila with motor and sensory neuron-specific knockdown of dUCH (Drosophila Ubiquitin carboxyl-terminal hydrolase) which is a homolog gene of human UCH-L1. The obtained results showed that the knockdown dUCH decreased the locomotive function in both larval and adult stages of Drosophila, and also gave negative effects to their learning and memorying abilities. These results emphasized the roles of UCH-L1 in the neuronal health and suggested the possibility of using D. melanogaster as model for further studies of disease mechanisms or drug screening.
Preparation of 5-hydroxymethylfurfural from fructose using Brønsted acid catalyst
Authors:   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam, Bich Phan Ha ,   Vietnam National University Ho Chi Minh City, Vietnam,   Institute of Public Health Ho Chi Minh City, Vietnam, Hoang Tran Phuong ,   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University Ho Chi Minh City, Vietnam
Published: January 2024

In the last two decades, ionic liquids have been emerging as green materials and attracted much attention from scientists due to their broad application in many fields such as catalysis, electrochemistry, and biomass conversion. 1-Methylimidazolium hydrogen sulfate and 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate ([MimC4SO3H]HSO4) were successfully prepared, and their chemical structures were elucidated by IR, HRMS. In this study, their catalytic activity was studied and compared with some inorganic catalysts through the preparation of fructose to 5- hydroxymethylfurfural (HMF) in the condition of stirring at room temperature. The result showed that among the tested catalysts for this reaction, [MimC4SO3H]HSO4 was the best one with a yield of 86% after 24 hours. In addition, this Brønsted acid catalyst could be reused five times without significant loss of catalytic activity. Base on previous literature and our results, the plausible mechanism of fructose dehydration into HMF was proposed in this study.
Diversity and distribution of trophic guilds of nematode assemblages in the Ham Luong estuary, Ben Tre province
Authors:   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam, Nguyen Thi My Yen , Tran Thanh Thai ,   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam, Le Que Lam Lam Nguyen ,   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam, Pham Thanh Luu ,   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam, Tran Thi Hoang Yen ,   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam, Xuan Ngo Quang ,   The Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology. 85 Tran Quoc Toan, District 3, HCM City, Vietnam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam
Published: January 2024

Studying the trophic guild of nematode assemblages contribute to infer their foods, therefor interprete the aquatic foodwebs and assess the environmental quality of ecosystem. Nematode communities play important roles in the aquatic foodweb, as the decomposers break down the detritus or as the intermediate chains in transferring of material and energy from decompsers as bacteria and producers as microalgae to higher consumers. The present study aimed to analyse the diversity and distribution of nematode trophic groups at six subtidal sations of the Ham Luong estuary in Ben Tre province in the dry season 2017. The results found four groups of feeding guild including swallowers, tear & swallowers, chewers, and suction-feeders. Two groups of swallowers and tear & swallowers were dominant, accounting for high proportions in the assemblage. While swallowers higly distributed in the upstream, tear & swallowers was high abundant in the downstream, chewers mostly presented in the middle part of the estuary. Nevertheless, suction-feeders was scarce distribution in the upstream side. The indices of trophic diversity were in average values, and less variation along the course of the estuary. The differences in the distribution of nematode trophic guilds might be resuted by the heterogeneities in the benthic environment, which need to be investigated in the next studies.
Fabrication of a composite film based on the extracted aloe vera solution and polyvinyl alcohol by freeze–thawing method
Authors:   Faculty of Applied Sciences, Ho Chi Minh city University of Technology and Education, Vu Nguyen Viet Linh , Nguyen Nguyen Thai Sinh ,   Faculty of Applied Sciences, Ho Chi Minh city University of Technology and Education, Thanh Tran Tam ,   Faculty of Environment, Ho Chi Minh University of Natural Resources and Environment
Published: January 2024

Aloe vera, a tropical plant, growing a lot in Vietnam, has been used in industries such as pharmacy, food and medicine. This paper presented a fabrication a film composed of Aloe vera extract (AV) and polyvinyl alcohol (PVA) by freeze–thawing method. This method was simple, easy-to-implement which involved some steps such as freezing at low temperature (below -20 °C), then defrosting at room temperature (25 °C) and then performing some consecutive cycles to generate the film. The AV‒PVA composite film was evaluated for its mechanical property by tensile testing, chemical composition by Fourier-transform infrared spectroscopy (FTIR), and morphology by scanning electron microscopy (SEM). The obtained AV‒PVA composite film was solidified with a high AV extract content of AV: PVA (1:1, v:v). A composite film with 25% (volume) AV achieved a high elongation–at–break of 317.8%, the tensile strength of 10.45 MPa and the Young’s Modulus of 3.29 MPa. The AV‒PVA composite film contained all specific functional groups of PVA and AV. Otherwise, the composite film displayed the presence of pores on surface. This composite film is a environmentally friendly material and would be potential in applications in the water filter and biomedical field.
Fabrication of ternary composite based on imidazole, nafion, and cellulose nanocrystals for fuel cell application
Authors:   University of Science, VNUHCM, Viet Nam, Nang Vu An , Mai Tran Anh ,   University of Science, VNUHCM, Viet Nam, Hoang Nguyen Long ,   University of Science, VNUHCM, Viet Nam, Van Nguyen Hoang ,   University of Science, VNUHCM, Viet Nam, Phong Pham Le Nam ,   University of Science, VNUHCM, Viet Nam, Van Le Hieu ,   University of Science, VNUHCM, Viet Nam
Published: January 2024

In this study, we report a facile solution method to prepare a three-component composite membrane including imidazole, Nafion® 117, and cellulose nanocrystals (NCI). The structure and properties of NCI membrane were characterized by Fourier -Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Electrochemical impedance spectroscopy (EIS). The NCI composite membrane was capable of proton conductivity under low humidity conditions for applications in fuel cell field. EIS analysis showed that the proton conductivity of the NCI film depends on both imidazole and Nafion and this value was about 32 times higher than that of pure CNC. SEM results showed that the component phases in the NCI material structure had a good interaction and no phase separation was observed. In addition, the results of TGA also demonstrated that when having CNC dispersed in the structure of the composite material, it hinders the thermal movement of PTFE chains in Nafion, making these chains not decompose at high temperatures. This work shows that the NCI composite membrane can be optimized to serve as a proton-conducting solid film for fuel cells operating in low humidity conditions.
The addition of quinonoid zwitterion into a hybrid organic–inorganic halide lead perovskite thin film could enhance the perovskite solar cells’ performance
Authors:   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam, Thanh Ngo Tung ,   Vietnam National University, Ho Chi Minh City, Vietnam, Duc Le Anh ,   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam, Minh Nguyen Tan ,   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam, Thi Nguyen Le ,   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam, Tuyet Nguyen Phuong ,   Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam
Published: January 2024

Solar cells based on hybrid organic – inorganic halide lead perovskite are potentially promising to be used in the near future. The quality of the perovskite thin film played an important role in the photovoltaic performance of perovskite solar cells. One strategy to improve the quality of the film was to utilize an additive into the precursor solution during the perovskite formation process. This paper presented the use of a quinonoid zwitterion compound at some concentrations from 0 to 2.0 mg.L-1 added to the PbI2 solution to synthesize the CH3NH3PbI3 perovskite thin film which was further implemented to fabricate solar cell devices. The perovskite films were analysed by X-ray diffraction, UV/Vis absorption spectroscopy and Scanning electron microscope and the obtained solar cell devices were characterized by current–voltage curve measurements. The results showed that the addition of the quinonoid zwitterion could increase the efficiency of the perovskite transformation with a film with more uniform morphology and less of voids, leading to a significant improvement of open circuit voltage values of the devices. The overall efficiency of the solar cells fabricated with a perovskite film using 0.5 mg.L-1 additive enhanced up to 2 % in comparison to those of non-additive ones.