bluuebunny/crossref_metadata_2025 huggingface dataset:
Évaluation d’impact des cantines scolaires sur les performances et la rétention scolaire au primaire : Cas du Bénin
Authors:   Université Mohammed VI Polytechnique, Maroc, Alladatin Judicaël , Borori Abel ,   Boutique des sciences et des savoirs Siabanni, Bénin, Gnanguenon Augustin ,   Université Mohammed VI Polytechnique, Maroc, Fonton Appoline ,   Université Mohammed VI Polytechnique, Maroc
Published: February 2022

Cette étude évalue l’impact des cantines scolaires sur les performances et la rétention scolaires des élèves béninois au niveau de l’enseignement primaire. Les données utilisées proviennent de l’enquête PASEC-2014 réalisée sur un échantillon représentatif de 3033 élèves du CM2 et de 732 élèves du CP. La méthode d’appariement sur score de propension (Propensity Score Matching) a été utilisée pour évaluer l’impact des cantines sur les performances des élèves en lecture et en mathématique et sur la rétention scolaire. Les résultats obtenus révèlent que les cantines ont un impact positif significatif sur les performances des élèves en lecture et en mathématiques. Ces résultats mettent en évidence le rôle primordial des cantines scolaires dans la rétention des élèves ainsi que l’impact globalement négatif des cantines sur l’abandon scolaire. De plus, les cantines améliorent plus les performances scolaires des élèves du privé comparativement à ceux des écoles publiques, même si elles semblent contribuer plus à la rétention des enfants des écoles publiques que ceux des écoles privées. Ce résultat suggère un besoin d’investigation approfondie des effets différenciés des types de cantines scolaires et d’autres facteurs socio-économiques sur les performances et la rétention scolaire.
Analysis Utilizing AI Techniques for Optimum Performance at the Low Tension and The High Tension Line In BESS
Authors: Gupta Ajay Kumar , Bansal Jyoti
Published: February 2022

Power quality became one of the most critical challenges in today’s modern power system. Utmost primary factors of power quality issues are non-linear fluctuating loads, system interruption, load variances, infrequent loads, and arc furnaces. As a matter of fact, there is occurrence of various electrical distortions, along with voltage spikes, voltage sags, and so forth. Several innovative techniques were employed for the development of circuits which resulted in minimised voltage stability as well as reliability.  Utility companies which are electrical are receiving a large quantity of complaints because of these challenges.  An approach is required now to explore the power quality challenges in industrial sector, corporate sector, municipal, or domestic sites. Therefore, a few techniques known as Flexible AC transmission system (FACTs) are used to enhance power quality. It is divided into two categories: namely series-FACTs and shunt-FACTS. As name itself define its architecture that in series-FACTS comprised of transmission line which is connected in series with module and connected in parallel in shun-FACTs.   We can alleviate the problems related to power quality with the help of these FACTS devices. D-STATCOM is one of the better devices available. D-STATCOM is a shunt-connected solid-state device employed at the distribution network to maintain load-side disturbances. It has exceeded the traditional capacitor being used improve power quality with it's lower upfront investment, outstanding dynamics, absence of static, and lower operational expenses. The sorts, architectural style, operating, control systems, and AI are all described in this article.
On the Inefficiency of Non-Competes in Low-Wage Labor Markets
Authors:   Drexel University, Potter Tristan , Hobijn Bart ,   Arizona State University,   Federal Reserve Bank of San Francisco, Kurmann Andre ,   Drexel University
Published: February 2022

We study the efficiency of non-compete agreements (NCAs) in an equilibrium model of labor turnover. The model is consistent with empirical studies showing that NCAs reduce turnover, average wages, and wage dispersion for low-wage workers. But the model also predicts that NCAs, by reducing turnover, raise recruitment and employment. We show that optimal NCA policy: (i) is characterized by a Hosios like condition that balances the benefits of higher employment against the costs of inefficient congestion and poaching; (ii) depends critically on the minimum wage, such that enforcing NCAs can be efficient with a sufficiently high minimum wage; and (iii) alone cannot always achieve efficiency, also true of a minimum wage-yet with both instruments efficiency is always attainable. To guide policy makers, we derive a sufficient statistic in the form of an easily computed employment threshold above which NCAs are necessarily inefficiently restrictive, and show that employment levels in current low-wage U.S. labor markets are typically above this threshold. Finally, we calibrate the model to show that Oregon's 2008 ban of NCAs for low-wage workers increased welfare, albeit modestly (by roughly 0.1%), and that if policy makers had also raised the minimum wage to its optimal level (a 30% increase), welfare would have increased more substantially-by over 1%.
Students' Online Distance Learning Readiness for Mathematics and Statistics Courses
Authors: Abdul Halim Bushra , Zainudin Siti Nursyahira , Fuzi Siti Fairus , Jama Siti Ramizah , Zahidi Nurul Emyza , Jusoh @ Hussain Nordianah , Wan Hassan Wan Hartini
Published: February 2022

In early January 2020, the whole world including Malaysia was threatened by the outbreak of coronavirus (Covid-19) pandemic.  In Malaysia, phases of Movement Control Order (MCO) were enforced to curb the spread of Covid-19 pandemic, and because of that, educational institutions were affected where learning must be continued by modifying face-to-face learning in campus to remote Online Distance Learning (ODL) at home for all the courses offered. This study investigates any significant difference between students’ ODL readiness dimensions for mathematics/statistics courses and the influence of students’ ODL readiness dimensions on mathematics/statistics performance. This research referred to five dimensions from the Online Learning Readiness Scale (OLRS); computer and internet self-efficacy, self-directed learning, learner control, motivation for learning, and online communication self-efficacy to measure students’ ODL readiness. Data were collected from 511 students in Universiti Teknologi MARA Melaka Branch of academic session March – July 2020 who took mathematics/statistics courses online. The statistical analyses used for this study were One-way repeated analysis of variance, one-way multivariate analysis of variance (one-way MANOVA) and multiple regression analysis. Results revealed that students taking statistics course showed higher readiness scores in computer and internet self-efficacy, and self-directed learning than students taking mathematics course. The results also show that students’ mathematics/statistics performance was influenced by self-directed learning in ODL. As a conclusion, students taking statistics course were more prepared and performed better in learning through ODL than students taking mathematics course.
Descriptive Study on the Level of OSH Awareness Among UiTM Cawangan Pulau Pinang Staff
Authors: Jaafar Rosley , Umar Norazah , Ibrahim Anas , Razali Wan Noorli
Published: February 2022

Safety and health are important factors of any organization to ensure smooth and effective functioning. Occupational safety and health (OSH) awareness among the workers in the prevention of occupational injuries and illness. Various programmes have been implemented by the government and private organizations to increase the knowledge and awareness of OSH in the workplace including among institution higher learning staff in Malaysia. A study was undertaken to identify factors influencing the awareness level of OSH among the staff of Universiti Teknologi MARA (UiTM) in Pulau Pinang Malaysia. A self-administered online questionnaire was distributed to the staff through UiTM email and 193 staff had responded. The questionnaire covered 43 questions and was divided into seven (7) factors that influence awareness level. The data were analyzed using the Statistical Package for the Social Sciences (SPSS) version 20 and presented in descriptive statistics. The study revealed that the highest level of awareness factor was OSH policy with a mean score of 4.90 while the lowest level factor was safety and health committee with a mean score of 3.90. The analysis of all factors indicated that non-academic staff awareness towards OSH is higher than academic staff with a mean score of 4.51 and 4.41 respectively. The university management should increase the role of the safety and health committee so that it can conduct more safety and health activities such as safety talks, training, and campaign through posters and signage on the campus. Good OSH management is very important to prevent an accident at the workplace towards the development of a safety culture.
Análisis comparativo de la ética del trabajo en cuatro tradiciones religiosas y su impacto sobre la organización económica y social: del judaísmo a la Fe bahá'í
Authors: Marqués Utrillas José Luís
Published: February 2022

Este artículo parte de la hipótesis desarrollada por Max Weber de que las diferentes concepciones del trabajo subyacentes en las cosmovisiones religiosas tienen un impacto decisivo sobre las formas de la organización económica y la acción social. Primera parte: cómo la tradición de escritura y estudio entre los judíos los llevó a su alto nivel intelectual en la Edad Media y al auge de intelectuales y artistas ahora. En la segunda: cómo el cristianismo conservó en los monasterios el saber, el trabajo y el arte, para evolucionar de forma distinta en la Europa protestante y la católica. La tercera parte analizará cómo el Corán promovió las ciencias y la economía en los primeros siglos del islam y por qué el puritanismo lo llevó a un declive progresivo. Finalmente se expondrán los presupuestos ideológicos de los bahá'ís que les favorecen para afrontar los retos de la globalización
Condiciones de salud de una población antigua del occidente de Mesoamérica: estudio de los habitantes del sitio arqueológico Los Limones, México (600-1000 d.C.)
Authors: Salazar Camacho Milena , Márquez Morfín Lourdes
Published: February 2022

Esta investigación evalúa las condiciones de salud de 29 individuos que habitaron el sitio Los Limones durante la fase Armería (600-1000 d.C.) para determinar si tenían alguna relación con la subsistencia agrícola que se ha propuesto para este sitio. Con base en la metodología estandarizada de indicadores de estrés, se realizó un análisis macroscópico de cuatro lesiones óseas y seis lesiones dentales. Las caries, los cálculos dentales, la pérdida de piezas dentales ante mortem y las reacciones periostales fueron las lesiones más frecuentes y se identificaron en individuos juveniles, adultos jóvenes y adultos de ambos sexos. La integración de los datos del medio ambiente, del contexto arqueológico y de la identificación de las lesiones óseas y dentales permitió sugerir que los antiguos habitantes del sitio Los Limones pudieron haber tenido una estrategia de subsistencia mixta que integró actividades como la agricultura, la pesca, la caza y la recolección de plantas y frutos silvestres.
Socialización, medios de comunicación y ética
Authors:   Escuela Profesional de Ciencias de la Comunicación, Universidad de San Martín de Porres, Perú, Guzmán Hurtado Zoila Marlubeth
Published: February 2022

En toda sociedad, cada uno de sus componentes y cada una de sus instituciones cumplen un rol determinante. El rol de los medios de comunicación es vital para sustentar la socialización, habiendo llegado incluso a ser llamados elementos democratizadores. Pero hoy en día están operando en contra de sus reales funciones y asumiendo a todas luces comportamientos antiéticos. Esto no solamente se pone de manifiesto en el periodismo cada vez más desprestigiado, también está operando en los distintos formatos y géneros de manera cada vez más acentuada. Los programas de entretenimiento incurren con frecuencia en la vulgaridad y con toda impunidad pisotean la Ley N° 28278 (Ley de Radio y Televisión), de tal manera que han llegado a generar la intervención del Poder Judicial, evidenciando que los medios de comunicación y los comunicadores no se pueden autorregular. Pero ¿por qué hemos llegado a esta crisis? ¿Qué pasó con los comunicadores, con los profesionales de la verdad? Es entonces cuando caemos en cuenta de que el comunicador, en sus distintas ramas, debe recuperar su identidad como profesional y no limitarse a ser solamente un buscador de likes o de rating.
Effects of a cognitive-behavioral skills building program on the mental health outcomes and healthy lifestyle behaviors of veterinary medicine students
Authors: Melnyk Bernadette M. , Hoying Jacqueline , Hsieh Andreanna P. , Buffington Brenda , Terry Ayanna , Moore Rustin M.
Published: February 2022

OBJECTIVE

To evaluate the effects of a cognitive-behavioral skills building program (ie, MINDSTRONG; The Ohio State University) on the mental health outcomes and healthy lifestyle beliefs and behaviors of Doctor of Veterinary Medicine (DVM) students.

Sample

DVM students (n = 62) before beginning their program at a large public Midwest land-grant university.

Procedures

All 171 incoming DVM students (class of 2024) were required to take the cognitive-behavioral skills building program (7 weeks in length) before starting their 2020 school year. Students were given the option to consent to the study portion of the program. Consenting participants completed a pre- and postsurvey containing demographic questions and 5 valid and reliable scales, including the Patient Health Questionnaire-9 that assesses depressive symptoms, the Generalized Anxiety Disorder-7 that evaluates anxiety, the Brief Inventory of Perceived Stress that measures stress, and the Healthy Lifestyle Beliefs and Healthy Lifestyle Behaviors scales. Descriptive statistics described sample characteristics, paired t tests assessed changes over time in the outcomes Personal Wellness Assessment, and Cohen’s d determined effect sizes.

Results

62 DVM students completed both surveys. Postintervention, students had significant improvements in depressive symptoms, anxiety, and healthy lifestyle beliefs and behaviors.

Clinical Relevance

Although this study used a small convenience sample of DVM students from a single university, a cognitive-behavioral skills building program demonstrated the ability to decrease rates of depression, anxiety, and suicidal ideation and improve healthy lifestyle beliefs and behaviors. Requiring DVM students to participate in such programming could provide benefit during their professional education and throughout their careers.
Measuring Reactance to Camcorder Symbols Linked to Online News
Authors: Bálint Blanka , Kósa István
Published: February 2022

The aim of the study is to test the validity of a short-scale measuring reactance to a camera symbol associated with online news, indicating the possibility of viewing video footage. The operationalization of reactance means a mixture of anger and negative cognitions preceded by the sense of danger of losing one’s freedom (Reynolds-Tylus, 2019). As the brief reactance scale elaborated by Hall and colleagues (2017) contains these elements, we assumed that it would constitute the appropriate basis for the elaboration of further brief reactance scales. Thus, we elaborated a brief reactance scale adequate for measuring reactance to camcorder symbols linked to online news. Data collection took place among the students of Sapientia University (Romania). For analysing the adequacy of the scale, we used confirmatory factor analysis, reliability analysis, and convergent validity analysis. We also checked to what extent the elaborated measuring tool could predict the avoidance of news linked with camcorder symbols. The results of this analysis show that in the case of people with high reactance to camcorder symbols, the increase of reactance leads to these people choosing less and less news linked with camcorder symbols. All these prove that despite its limitations the scale constitutes an adequate tool for the measuring of reactance to camcorder symbols.
Best Practices of CSR Reporting in Romania
Authors: Tőkés Gyöngyvér Erika
Published: February 2022

The aim of the study is to examine the content and quality of online CSR reports of the eight large companies with the highest CSR index scores in Romania in 2020. The CSR reports of the eight large companies examined were analysed on the basis of two types of web content: on the one hand, on the basis of CSR content published on the company website and on the other hand on the basis of data published in sustainability or CSR reports uploaded to the website. The research method was thematic content analysis. The analysis criteria of the mentioned content were developed on the basis of the reporting principles of the GRI framework and the ISO 26000 standard. The findings showed that the principles of content and quality of non-financial reporting prevailed in the sustainability reports, while the data published on the websites was more for wider information.
Reconnect: Cultural Content and Audiences in the Digital Environment
Authors: Koleva Petya , Berbenkova Milena
Published: February 2022

Several studies have addressed the challenges faced by cultural and creative professionals and businesses since the emergence of the global COVID-19 pandemic. Some success stories have surfaced around larger organizations that managed to adapt quickly because they had been preparing for the digital era. The focus of the study presented here adds the much-needed viewpoint of those individuals who form the target audiences and are vital for the future of any CCI organization. These are the results of a public survey aimed at informing directly cultural organizations that experiment with new creative approaches and are adjusting to the transformations that have taken place. Findings are vital for organizations from smaller cultural markets while key conclusions shed light on the new disposition of the public towards existing and future formats of cultural offers online that are valid for contemporary audiences in general. These cover several key observations regarding the most popular type of cultural content and events online; the engagement rate of different audience groups; the most preferred duration of culture in video format; gender affinities influencing the engagement with cultural content online; the motivations and barriers for attending cultural events online, ways to keep the audiences informed, and finally, which new forms of cultural and creative offers would the public be willing to attend online in the recent future. The article demonstrates that knowing the target audience and using data analytics on public dispositions while creating new content can empower CCI organizations. This claim is also based on the successful experience of pilot offers created by CCIs that have benefited directly from the research results of Intercultura Consult’s 2021 project. Work continues in a new project empowering cultural organizations to incubate experimental offers (digital dimension including). The goal is to enhance their connection with key audiences.
Computed tomography log scanning – high technology for forestry and forest based industry
Authors: Gergeľ Tomáš , Bucha Tomáš , Gejdoš Miloš , Vyhnáliková Zuzana
Published: February 2022

Heterogeneity in the tree trunks’ shapes and quality is not often reached fully using raw material potential in grading processes of tree and stand and the following sawmill processing.

Therefore, optimization of given processes is a current topic of research and is part of the operational practice. In the contribution we submit a survey of solving the given problems in the European and Slovak conditions. A significant impulse for solving problem at a new level is a significant progress in the field of industrial computed tomography. New and fast CT scanners have been developed and they enable to increase valuation by 15% in coniferous trees and by 24% in broadleaf trees. In the contribution we analyze period of returns of CT scanner’s implementation into the sawmill process within Slovak context for small, medium-sized and big sawmills. Results show that period of returns for big sawmills is approximately for years, for medium-sized sawmills is eight years when processing coniferous softwood or three to eight years in case of broadleaved processing. In the final synthesis we present a concept of interlinking the 3D scanner and technologies of laser woodcutting with the outcomes allowing to optimize stand grading and maximize profit of the given raw wood in the sawmill processing.
Salvage felling in the Czech Republic‘s forests during the last twenty years
Authors: Zahradník Petr , Zahradníková Marie
Published: February 2022

The incidence of salvage felling is a significant indicator of stands‘ health and stability. Health is mainly indicated by biotic and anthropogenic factors, while abiotic effects are primarily an indicator of a stand’s stability. All these factors influence each other and subsequently they can result in salvage felling. For the Czech Republic, there have been relevant data for the period since 1964. Actually, recent data cover approximately 70% of the Czech Republic´s area in the twenty-year period assessed in this text. During this period, the volume of salvage felling amounted to 89.2 million m3 which represents 28.4% of total felling in this period. The largest share is caused by abiotic effects (18.6%), next by biotic agents (9.6%) and anthropogenic are only responsible for 0.2%. In the last two years, the volume of salvage felling caused by biotic agents was higher than the volume of salvage felling caused by abiotic and anthropogenic agents for the first time. In terms of biotic agents, almost the whole volume is represented by bark beetle wood as a result of spruce stands infestation by the European spruce bark beetle – Ips typographus (L.) and double-spined bark beetle – Ips duplicatus (Sahl.), and to a small extent also by other species of bark beetles on spruce, pine and occasionally other wood tree species. In the last three years, mainly the incidence of the Ips typographus L., has concentrated in North Moravia and Silesia. Currently, it is also spreading in South Moravia and Bohemia and in districts along the state borders with Austria and Germany, with the most serious situation in this region being the one in the Bohemian-Moravian Highlands.
Combined fertilizers versus dolomitic limestone: A comparative study from a forest habitat with Norway spruce
Authors: Kučera Aleš , Rosíková Jana , Pecháček Jan , Dundek Peter , Vavříček Dušan
Published: February 2022

The research paper with character of case study deals with the influence of amelioration on soil as well as the Norway spruce nutrition and growth, with the focus on dolomitic limestone and combined fertilizer applications. The study was performed in the 7-year-old forest stand (Nízký Jeseník Mountains, Czech Republic, 100% Norway spruce, podzol, mor humus form, slightly undulated slope, 770 m a.s.l.). The soil properties (soil reaction, nutrient status, C/N ratio and cation exchange capacity), the plant nutrition, the plant biomass production and the health status were measured. Neither the expected significant increase in pH due to liming in the root zone nor the increase in calcium and magnesium in the soil was confirmed. In the dolomitic limestone treatment, the highest hydrolytic acidity reaching 260 mmol+/kg, the worst development of assimilatory organs, the growth and health status of individuals were ascertained one year after the usage. The application of combined fertilizers resulted in the highest response in the needle biomass production (0.35 g/100 needles compared to less than 0.30 g/100 needles in the dolomitic limestone treatment), in the potassium and phosphorus nutrition status (suboptimal 4–4.5% of potassium in dolomitic limestone and the control treatment compared to optimal 5.5–7.5% in the combined fertilizers treatments) and simultaneously to the optimization of the health status. Specifically, in forest stands, the effect of dolomitic limestone is rather overestimated and furthermore, chemical amelioration requires the detailed knowledge of the forest site.
Substitution of Norway spruce for Douglas-fir: changes of soil microbial activities as climate change induced shift in species composition – a case study
Authors: Podrázský Vilém , Kupka Ivo , Prknová Hana
Published: February 2022

Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is the most common utilized introduced tree species in the tem-is the most common utilized introduced tree species in the temperate zone, planted in many European countries. Also, in the Czech Republic it represents the most planted exotic species as well. Its planted area exceeds 6,000 ha and represents 0.25% of the forest area of the country. In the last years, this species is supposed as convenient substitution for declining Norway spruce (Picea abies [L.] Karst.) stands under current climatic change (extreme drought, bark beetle outbreak). The changed species composition affects also soil dynamic processes, including litter decomposition and transformation. In the presented study, the respiration rate and nitrification intensity were compared in the stand parts dominated by Norway spruce and Douglas-fir in comparable site conditions (410 m a.s.l., 650 mm, 8 ºC, gleyic Luvisol, fresh oak-fir site with Oxalis acetosella, age 97 years). Analyses were performed in laboratory conditions by standard methods determining actual (basal) and potential respiration activity and intensity of ammonia and nitrate ion production. Admixture of Douglas-fir considerably intensified decomposition activities (soil respiration) and profoundly increased the nitrification rate in the surface humus and uppermost mineral soil layer – Ah horizon. Increased interest in the Douglas-fir silviculture needs increased care for forest soil dynamics with respect of nitrogen balance.
Does shelterwood regeneration on natural Scots pine sites under changing environmental conditions represent a viable alternative to traditional clear-cut management?
Authors: Brichta Jakub , Bílek Lukáš , Linda Rostislav , Vítámvás Jan
Published: February 2022

In the context of climate change, the crucial question is how silvicultural treatments should be modified, in order to reach favourable conditions for initiating natural regeneration of forest stands. The aim of the study was to evaluate the influence of clear-cutting, basal area reduction (0.4, 0.6 and 0.8) and soil preparation (milling cutter, forestry mulcher, brush rake and control variant without soil preparation) on the regeneration of Scots pine (Pinus sylvestris L.) in the conditions of natural pine sites (Northern Bohemia). Seedling numbers, heights and crown widths were recorded on transects representing all combinations of stand densities treatments and soil preparations variants three years after the silvicultural operations. Seed traps were installed to determine the numbers of seeds from 2016 to 2018. Soil water potential (Delmhorst Instrument Company) and soil temperature (sensor Pt1000 A–class sensors, EMS Brno) were measured. All variants of soil preparation had higher numbers of seedlings compared to control variant. When comparing stand densities, total numbers of seedlings were the highest in stand density 0.4 (cutter 32,402 ± 34,208 S.D. ind.ha−1; mulcher 26,832 ± 24,088 S.D. ind.ha−1; rake 24,496 ± 22,913 S.D. ind.ha−1). This stand density was also beneficial with respect to seed numbers, seedling characteristics and soil moisture and temperature characteristics. We conclude that shelterwood regeneration on natural Scots pine sites is promising silvicultural approach and may become an important tool in mitigating negative effects of climate change in the future.
Effects of forest disturbance on seasonal soil temperature changes in the Tatra Mountains in southern Poland
Authors: Siwek Joanna Paulina
Published: February 2022

The purpose of the study was to examine the effects of forest disturbance on seasonal changes in soil temperature in the Tatra Mountains (Poland). In the years 2015–2020 soil temperatures were measured at a depth of 20 cm on north- and south-facing mountain slopes in a catchment where forest was disturbed by hurricane-force winds in 2013 and in a control neighboring woodland catchment. The effect of forest disturbance was manifested first and foremost in an increase in the soil temperature during the summer months – average by 1.8 to 2.4 °C on a south-facing mountain slope – and by about 1 °C on a north-facing slope. The buffer effect of forest on soil temperature can be observed via lower coefficients of correlation between soil temperature and air temperature in a woodland catchment versus a disturbed catchment in the summer. In the winter, the effect of forest disturbance on soil temperature was less pronounced than in the summer. Small differences in soil temperature in the winter between the woodland catchment and the disturbed catchment were associated with the presence of snow cover and its capacity to yield thermal insulation. Good insulation of the soil from the atmosphere generated by snow cover yielded a very weak relationship between soil temperature and air temperature in the winter. In springtime the soil temperature increased the fastest on a south-facing slope in the disturbed catchment while in the autumn season, soil temperatures declined most rapidly on a slope facing north in the disturbed catchment.
Preliminary studies of Volten VR4®
Kaempferia parviflora herb extracts on blood glucose levels in human type-2 diabetes mellitus and its mineral element analysis
Authors: Mohamad Ahmad Sabry , Nordin Muhammad Noor , Ani Ismail Che , Jemberang Johan , Ishak Reezal , Hasan Ahmad Najib , Ahmad Muhammad Imran , Omar Mohd Rahman , Hamzah Roszymah
Published: February 2022

Introduction

Volten VR4® capsules containing herb extract of Kaempferia parviflora has been claimed to reduce blood glucose in patients with diabetes.

Objectives

This preliminary study is conducted to evaluate the efficacy of Volten VR4® on healthy individuals and type-2 diabetes mellitus volunteers. The extracts of 400 mg capsules of Kaempferia parviflora (KP) were used to measure the blood glucose level of 2-hour postprandial.

Methods

The healthy group consists of 15 young adults aged 20-30 with no history of serious diseases, while the diabetic group includes 12 individuals aged 35-75 diagnosed with type-2 diabetes mellitus. Data were validated through the Willcoxon and Friedman test statistics and error distribution. The investigation was continued to trace the capsules contents of elements using inductively coupled plasma optical emission spectrometry (ICP-OES) techniques.

Results

It has been shown that KP reducing blood sugar levels has been associated with flavonoids and methoxyflavones components. The result specifically showed that consuming VR4® capsules can significantly reduce blood glucose, either at the state of fasting or postprandially. In the study the content of mineral and heavy metal elements in VR4® capsules has been evaluated.

Conclusion

Volten VR4®
Kaempferia parviflora extract is safe to be consumed at a single dose of 400 mg. The study also has shown that the participants are free from adverse reactions and hypoglycaemia.
Phytochemical screening and galactagogic attributes of Pergularia daemia (Forssk.) Chiov. leaf extract in lactating mice (Mus musculus)
Authors: Patra Monoj , Giri Santosh Kumar , Chowdhury Subhas , Pal Jayeeta , Saha Nimai Chandra , Biswas Surjyo Jyoti
Published: February 2022

Introduction

Pergularia daemia (Forssk.) Chiov. [PD] is used as a galactagogue by various tribes in Purulia district, India, lacks a scientific basis.

Objectives

The purpose of the study was to determine whether administration of aqueous leaf extract of P. daemia can increase milk production in lactating mice and encourages development in suckling pups.

Methods

30 lactating mice (n=6 per group) with a minimum of 5 pups each were treated with the aqueous PD extract at 50, 100, 150 and 200 mg/kg body weight while the control group was administered with only distilled water. The mice were daily fed with aqueous leaf extract via gavage, which started at day 3 and continued to day 15 post-partum and milk secretion was assessed by the weight-suckle-weight method. The qualitative estimation, UV-vis analysis and GC-MS study of the leaf extract was also done for the presence of phytoconstituents.

Results

Administration of aqueous leaf extract led to a considerable increase in milk production (28.1%) and the pups gained weight substantially (p<0.05) when compared to control. Milk production was enhanced in mice treated with 150 mg/kg b.wt. of leaf extract compared to other doses (p<0.05). The GC-MS analysis of the aqueous leaf extract of P. daemia revealed 20 major peaks, some with small retention time and also revealing presence of several phyto-estrogenic compounds.

Conclusion

The present study effectively demonstrated that aqueous leaf extract of PD enhanced milk production in mice and might be used as an alternative strategy for increasing milk production and can be extrapolated to farm animals and human beings.
Kinetic study on peroxidase inactivation and anthocyanin degradation of black cherry tomatoes (Solanum lycopersicum cv. OG) during blanching
Authors: Ha Ho Thi Ngan , Thuy Nguyen Minh
Published: February 2022

Introduction

Blanching is a necessary treatment stage in processing of tomato products to inactivate enzymes. However, it may cause the degradation of nutrients.

Objective

In this study, the kinetics of thermal peroxidase inactivation and anthocyanin degradation in black cherry tomatoes (cv. OG) were determined to predict the quality changes during the blanching.

Methods

Tomatoes were blanched at five levels of temperature (75–95oC) for five time periods (30–150 s).

Results

It was found that as the blanching temperature increased and the blanching time is prolonged, more peroxidase was inactivated and the greater number of anthocyanins was lost. The thermal peroxidase inactivation and anthocyanin degradation showed an apparent first-order reaction with the activation energy of 129.96 kJ/mol and 65.99 kJ/mol, respectively. Peroxidase and anthocyanin in black cherry tomatoes were found to be heat-sensitive.

Conclusion

These kinetic parameters were necessary to select and design appropriate blanching conditions for black cherry tomatoes on larger scale processing.
Amplifier circuit with LM324 operational amplifier Analytical calculation, Octave and Orcad LITE simulation
Authors: Puchianu D.C.
Published: February 2022

The study determines the time and frequency behavior of the LM324 operational amplifier. It determines the voltage amplification, the amplification given in dB, the waveforms made with the help of the Octave and Orcad Lite simulator and the observation a fairly good correlation between the analytical calculation and the simulation media used.
Electricity Consumption Measurement System Using ESP32
Authors: Gheorghe A.C. , Stan E. , Udroiu I.
Published: February 2022

The paper proposes the development of an IoT measurement system that offers the user the possibility to monitor and record the electricity consumed by a consumer through the Blynk application. In monitoring electricity one of its most important aspects is the calibration of the sensors used. Accurate and reliable detection is the key factor in measuring and managing electrical equipment. Fundamental physical quantities such as voltage and current are useful for determining all other electrical quantities. The ESP32 development board used to develop the system has 18 channels ADC (analog to digital converter) and supports a Wi-Fi connection at the access point and implicitly to the internet. The developed system can measure the voltage (U), current (I), power consumption (W) and consumption / hour (kWh) of a consumer, in my case for the consumer I used a light bulb with a power given by the manufacturer of 10W. The measured values are displayed on the LCD display of the system or through the Blynk application which also allows the registration of these values for a period of 12 months.
The Equivalent Circuits Thévenin and Norton
Authors: Staniloiu Marius , Popescu Horațiu , Rezmeriţă Georgiana , Iordache Mihai
Published: February 2022

The main objectives of this paper are to correctly define the equivalent Thévenin and Norton circuits and to presents the complete and exact proof of Thévenin and Norton theorems. These circuits allow the separation of the linear portions of the electronic circuits from the nonlinear ones and in this way the polarization process of the electronic devices becomes much more efficient. When linear and/or nonlinear analyzed circuits have a small number of nonlinear circuit elements, their analysis, synthesis, and simulation are performed much more efficiently if the nonlinear part of the circuit is separated from the linear one. By determining the equivalent Thévenin or Norton circuits in relation to the load to connected terminals of a system with two or more magnetic coupled coils, that are part of the wireless power transfer systems, optimal load parameters are determined so that the maximum active power is transmitted to the load.
Reactive Power Management in a Grid-Connected Photovoltaic Power Station: A Case-Study
Authors: Cazacu Emil , Groşanu Dan-Valeriu , Petrescu Lucian
Published: February 2022

The paper presents an applicative study on the power quality and energy efficiency operation for a photovoltaic power station with an installed capacity of 8.5 MW. The various operating regimes of the main network elements within the investigated photovoltaic plant are qualitatively and quantitatively. The reactive power flow in the plant that is permanently connected to the grid is especially examined. Thus, the losses within the power transformers and medium voltage cables in the plant are calculated due to the imposed by the load (often deforming and unbalanced regimes). In this manner, opportunities are identified to increase the energy efficiency of the entire system but also methods to improve the quality of energy delivered at the point of its connection to the local energy system.
The Impact of Global Crisis on the Subsidies PAID to Retailers and Wholesalers in Eastern European and Central Asian Countries
Authors: BALAS Ayse Nilgun , KAYA Halil Dincer
Published: February 2022

This study examines the impact of the 2008-2009 global crisis on subsidies paid to retailers and wholesalers. The results indicate that a significantly larger proportion of retailers received subsidies after the global crisis. Female ownership and top manager’s experience level did not matter in receiving significantly higher subsidies after the global crisis, but firm size, firm type, top manager’s gender, and whether or not the firm has an internationally recognized quality certification had made a difference in terms of subsidies received after the crisis. Our results indicate that a significantly larger proportion of wholesalers had received subsidies after the global crisis. While firm size did not matter for wholesalers, firm type, top manager’s gender and experience level, whether or not the firm has a female owner, and whether or not the firm has an internationally recognized quality certification made a difference in terms of subsidies received after the crisis.
Comparative Analysis of the Characteristics of Public Procurement Systems in Germany, France and Romania
Authors: PREDA Ionel
Published: February 2022

In public procurement, an important role is played by the analysis of the way public procurement takes place in other European Union (EU) countries. Although public procurement in EU Member States are governed by the same general rules established by a series of Directives that Member States have to transpose into national law, there are a number of significant differences and characteristics between public procurement systems. These differences are very important as they can lead to the identification and adoption of measures that can generate a number of effects, such as: increasing the efficiency of the use of budget funds, reducing the time of a procurement procedure, reducing the number of complaints, increasing the number of tenderers that participate in procurement procedures, encouraging the participation in procedures of small and medium enterprises, etc. The article describes an analysis of the main features of public procurement in the two most important EU member states, namely Germany and France, which are analysed in comparison with the public procurement system in Romania
Hydrogen Adsorption/desorption on lithium Alanat Catalyzed by Ni/C for Sustainable Hydrogen Storage
Authors:   Master Program, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sriwijaya, Amelia Icha , Rohendi Dedi , Rachmat Addy
Published: February 2022

LiAlH4 alloy has demonstrated the potentially to become one of the hydrogen storages with high storage capacity. In this research, the formation of LiAlH4 alloys with dope and undope Ni/C catalysts and characterization and testing of hydrogen adsorption/desorption capacities using these alloys have been carried out. The alloy was made by the milling method and the resulting alloy was characterized using XRD analysis. The adsorption capacity test of the alloy was carried out by the gravimetric method at various pressures. The adsorption capacity of the LiAlH4 alloy by adding additives in the form of Ni/C as much as 5%w/w. It was proven to increase the hydrogen adsorption capacity compared to undoped catalyst with the highest storage capacity at a pressure of 3 bar of 13.06%w/w compared to undoped a catalyst of 9.84%w/w at the same pressure. Meanwhile, the highest hydrogen desorption capacity was 53.56% w/w (dope catalyst) and 41.75% w/w (undope catalyst).
Bioethanol from Pineapple Peel with Variation of Saccharomyces Cerevisiae Mass and Fermentation Time
Authors:   Department of Chemical Engineering, Postgraduate program, Universitas Muhammadiyah Palembang, Yusmartini Eka Sri , Mardwita Mardwita , Marza Junanda
Published: February 2022

The availability of energy from fossil fuels is gradually decreasing. Bioethanol is one of the biofuels which is an alternative energy that can be used as a substitute for petroleum. In Indonesia, in general, the manufacture of bioethanol uses raw materials that compete with foods such as cassava, sugar, and tubers. however, in this research the raw material used is derived from lignocellulosic biomass from pineapple peel. Therefore, this research aims to utilize pineapple peel which is its waste as raw material for making bioethanol through a fermentation process. The fermentation process uses yeast mass and fermentation time as variables where the yeast mass used is 20, 25 and 30 g. while for the fermentation time for 5 and 9 days. In the distillation process, the operating conditions are 78.4 °C for low pressure temperature, and the next step is to analyze the bioethanol produced. Based on the research that has been done, the highest bioethanol content was obtained at 70% with the addition of 25 g of Saccharomyces cerevisiae with a fermentation time of 9 days. From these operating conditions, obtained bioethanol with a concentration of 70%, with a density of 0.8438 gr/mL, and a refractometric index of 9.581.
Optimization of Bio-Oil Pyrolysis Product from Palm Empty Fruit Bunches over H-Zeolite Catalyst using Response Surface Methodology (RSM)
Authors:   Doctoral Program, Faculty of Mathematics and Natural Sciences, University of Sriwijaya, Fanani Zainal , Rachmat Addy , Hasanudin Hasanudin , Said Muhammad
Published: February 2022

Bio-oil pyrolysis product considered as a promising resource of hydrocarbon compound that can be used as alternative fuel or other application. Palm empty fruit bunch (PEFB) based bio-oil converted into hydrocarbon trough pyrolysis over sulfate activation natural zeolite. Here, we reported an optimization process of bio-oil pyrolysis specifically on temperature and catalyst dose variables by using response surface methodology (RSM). Prior conversion process, PEFB was analyzed to determine cellulose, hemicellulose and lignin content. Sulfate activation natural zeolite confirmed its acidity by ammonia and pyridine adsorption calculated by gravimetric method. Two independent variables namely temperature and catalyst weight used in optimization process by RSM whereas response variable is conversion percentage. Analysis result on cellulose, hemicellulose and lignin content are 45.39%, 30.36% and 20.5% respectively. Catalyst acidity determination based on ammonia and pyridine adsorption gave 1.002 mmol/g and 0.1994 mmol/g. Optimum condition of hydrocracking achieved at 568 °C and 2.1088 g catalyst weight with the product obtained at 62.21% conversion. The best product density is 1.086 g/mL obtained at hydrocracking temperature 554 °C and 2.0362 g catalyst. Based on GC-MS analysis, it was confirmed that the product comprises more straight-chain hydrocarbon than cyclic one. RSM calculation able to formulate the feasible model equation to predict the conversion percentage. The equation is; percent conversion = 60.059 + 14.268T + 9.783W – 25.649T2 – 18.809W2 + 3.114TW, whereas model equation for response variable on product density; ρ= 1.09103 – 0.12356T – 0.09744W + 0.11489T2 + 0.28888W2 – 0.00740TW
Biofuel from Pyrolysis Waste Lube Oil of Refinery Unit III Using Fly Ash of Coal Combustion as a Catalyst
Authors:   Applied Master of Renewable Energy Engineering, Politeknik Negeri Sriwijaya, Sandika Nedia , Bow Yohandri , Hasan Abu
Published: February 2022

Lube oil waste obtained from Utilities Unit, Crude Distillation Unit, and Crude Distillation & Light End Unit at Refinery Unit III Plaju Palembang South Sumatra. The process of pyrolysis of lube oil waste using fly ash catalyst is expected to produce fuel oil. Lube oil waste pyrolysis uses Fly Ash catalysts with a total catalyst of 500 g with a temperature range variation of 0-85, 85-16, 165-250, 250-300, and 300-350oC, while pyrolysis of waste lube oil without catalysts with a variation in the temperature range of 0-85, 85-165, 165-250, 250-300, and 300-350 oC. Temperature range variations are referenced based on boiling route solvent fraction (0-85 C), premium fraction (85-165 oC), kerosene fraction (165-250 C) and diesel (250-350 C). Solvent fraction cannot be analyzed because there is no product result whether it is pyrolysis process using catalyst or without catalyst, Premium Fraction is only produced using catalyst, analysis result Octane Number 76.6. Sulfur content, Density and flash point analysis of pyrolysis products using catalysts and without catalysts in accordance with kerosene products in the market. Solar fraction of pyrolysis process using catalyst and without catalyst, Analysis results cetane numbers 43.2 and 45.6 have not met the specifications of solar products
Alkaloids of Fagraea fragrans (Tembesu) Fruits
Authors:   Department of Chemistry, Faculty of Sciences, Sriwijaya University, Inderalaya, Basir Dasril , Miksusanti Miksusanti , Susilawati Susilawati , Maizur Dian Dwita
Published: February 2022

The aim of this paper is to visualize the alkaloids of Fagraea fragrans fruits therefore the fruits can be scientifically used as herb traditional medicines and phytocosmetics. Three alkaloids have successfully been identified from those Fagraea fragrans fruits, Loganiaceae. They are gentialutine, gentianine, and isaindigotone. The alkaloids were alternately explored by means of ether and 2% H2SO4 extractions. The sulphuric acid phase was naturalized with ammonium chloride and then extracted with ethyl acetate. The residue were then subjected to silica gel G60 (70-230 mesh) column chromatography and eluted with 40% ethyl acetate in n-hexane. The LC-MS spectral of alkaloids gave the protonated molecular ion peaks at m/z (r.t. minute) = 150.08 (1.39), 176.06 (4.80), and 351.37 (5.24) respectively