bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionic chromatographic determination of iodides, nitrites and bivalent iron in water with amperometric detector
Authors: Abramov Evgeny G. , Malysheva Alla G.
Published: December 2020

Introduction. The majority of ionic chromatographic methods approved in our country for assessing the quality and chemical safety of water for the content of controlled anions and cations are developed using conductometry. However, quantitative determination of micro concentrations of cations and anions in drinking water and other water bodies against the background of macro concentrations of other components due to their interfering influence by the method of conductometric ion-chromatographic analysis is not possible. Material and methods. The tap water in Nothern East Administrative district of Moscow was used. The “Stayer” ion chromatograph with amperometric and conductometric detectors and separating columns was used. The column Phenomenex Star Ion A-300 100/4.6 was used for the determination of iodide. The column Shodex IC SI-52 4E 250/4, 6 was used for the determination of nitrite. The column Shodex IC YS-50 150/4.6 was used for the determination of bivalent iron. Results. Chromatograms of ion chromatographic analysis with amperometric and conductometric detections of tap water with different contents of target ions are presented. It is shown that it is impossible to determine the target components using the standard method with conductometric detection. The content of accompanying ions (chlorides, nitrates, and sulfates), exceeding the concentration of nitrite and iodide by tens of thousands of times, was not prevented by the determination. Discussion. The high efficiency of the proposed method for determining iodides, nitrites, and bivalent iron is provided due to their anode discharge in the electrochemical cell of the detector. Interfering components (chloride, nitrate, phosphate, and sulfate) neither participate in the anodic oxidation process and nor generate an electrical signal; that allows determining micro concentration of nitrite and iodide ions and bivalent iron in virtually any aqueous system containing an excess of chlorides, nitrates, sulfates. Conclusion. Authors proposed a highly sensitive ion - chromatographic amperometric determination of iodide, nitrite ions and bivalent iron in water and other water bodies. It allows eliminating the interfering influence of macro concentrations of accompanying components. The determination is performed by direct insertion of the sample into the chromatographic system.
Безусловный базовый доход: от утопии к реальности
Authors: Некрасов Ф.О.
Published: December 2020

В статье рассматривается концепция Безусловного Базового Дохода. Описываются основные этапы развития концепции, анализируются результаты экспериментов с безусловными трансфертами. В российском контексте описывается актуальность введения Базового Дохода. Предлагаются источники финансирования расходов на Базовый Доход, а также возможный способ совмещения безусловных выплат с пенсионной системой.
Потребление стали и структурные изменения в системе оборота металла
Authors:   ИНП РАН, Устинов В.С.
Published: December 2020

Показаны ключевые тенденции, связанные с потреблением стали в России и других странах мира. Дана характеристика особенностей российской системы оборота металла. Описаны структурные изменения, произошедшие в российской системе оборота металла в 2000-2018 гг. Проведен анализ взаимосвязи валового накопления основного капитала и потребления стали в ведущих странах мира в 2002-2018 гг. На базе проведенного анализа представлены прогнозные сценарии потребления стали в РФ.
Здоровье трудовых мигрантов из ЕАЭС в России (на примере мигрантов из Киргизии)
Authors:   ИНП РАН, Полетаев Д.В.
Published: December 2020

На базе двух социологических исследований, проведенных автором в 2016 и 2017 гг. среди трудовых мигрантов из Киргизии в России и Казахстане, выявляется постепенное ухудшение состояния их здоровья, особенно после пяти лет проживания. В связи со снижением уровня осведомлённости о состоянии здоровья, особенно о заражённости ВИЧ и туберкулезом, предлагается модернизация системы медобслуживания в ЕАЭС.
Приоритеты интеграции финансовых рынков и дедолларизации на евразийском пространстве в свете концепции формирования общего финансового рынка ЕАЭС
Authors: Мишина В.Ю. , Хомякова Л.И.
Published: December 2020

В 2019 г. была утверждена Концепция формирования общего финансового рынка ЕАЭС. Ее реализация связана с развитием общего финансового и валютного рынка, а также платежного пространства. В этой связи существенное значение приобретает необходимость оценки текущего положения стран ЕАЭС в указанных сферах, а также подготовка предложений по их развитию. В статье представлен анализ взаимных трансграничных расчетов в национальных валютах стран ЕАЭС, сделаны выводы о недостаточно раскрытом потенциале и рисках таких расчетов. В качестве позитивного примера сотрудничества рассмотрено развитие инфраструктуры финансовых рынков функционирование Интегрированного валютного рынка ЕАЭС. Рассмотрены факторы и перспективы рубля как региональной валюты на евразийском пространстве. Даны предложения по дедолларизации и активизации операций в национальных валютах стран ЕАЭС.
Effects of the Cool Beginnings: Modulation of SiO2 Nanoparticles
Authors: BOYLU Bilge , ARSLAN Osman , ABALI Yüksel
Published: December 2020

As one of the most prominent anticake agent, SiO2 nanoparticle synthesis method was modified and investigated for a better understanding of the fabrication process. Hence, tetraethoxysilane presursor was subjected to varying synthesis procedures such as concentration change and surface modification ligants. pH value and all the other material composition was kept the same and by implying sol-gel reaction mechanism, basic catalysis and temperature allowed us to obtain spherical and monodispersed nanoparticles. Additionally surface composition which provides hydrophobic character could also be controlled by spontaneous reaction of the long alkyl chain containing alkyltrialkoxysilanes with tetraalkoxysilane. Statistical analysis of the nanoparticle sizes with atomic composition, unveiled that SiO2 nanoparticle size can be modulated sensitively. Monodispersed, spherical and surface controlled nanoparticles seems promising candidated for the applications in sensors, controlled surface coatings and chemical delivery applications.
Basic Concept of Embedded ‘C’: Review
Authors: Agrawal S. C. , Singh Sanjay , Gautam Arun Kumar , Singh Mahesh Kumar
Published: December 2020

The use of C language to program micro controllers is becoming too common. And most of the time its not easy to build an application in assembly which instead you can make easily in C. So its important that you know C language for micro controller which is commonly known as C remains a very popular language for micro-controller developers due to the code efficiency and reduced overhead and development time. C offers low-level control and is considered more readable than assembly. Many free C compilers are available for a wide variety of development platforms. The compilers are part of an IDEs with ICD support, breakpoints, single-stepping and an assembly window.
El embarazo adolescente como un problema de salud pública en Latinoamérica
Authors:   Universidad Católica de Cuenca, Ecuador, MARTINEZ Enriqueta A. , MONTERO Gloria I. ,   Universidad Católica de Cuenca, Ecuador, ZAMBRANO Rosa M. ,   Universidad Católica de Cuenca, Ecuador
Published: December 2020

El embarazo adolescente es una problemática de índole biológico, psicológico y social que involucra a la familia y a la sociedad. Esta investigación parte de un enfoque cualitativo con alcance descriptivo y exploratorio mediante el uso de revisiones de estudios realizados en Latinoamérica. Como resultado se destaca que en Latinoamérica el número de embarazos adolescentes es creciente, lo cual indica que algo está fallando en la educación sobre el manejo de la sexualidad a temprana edad.
La dimensión ética del contador público en el caso Odebrecht
Authors:   Corporación Universitaria, Colombia, HERNANDEZ-ROYETT Javier , FRANCO-OCAMPO Diana P. ,   Universidad del Sinú Elias Bechara Zainúm, Colombia, GALINDO-CARDENAS Saul ,   Universidad del Sinú Elias Bechara Zainúm, Colombia, BERNAL Omaira ,   Corporación Universitaria, Colombia
Published: December 2020

El artículo descriptivo argumentativo, hace una recopilación teórica acerca del escándalo financiero Odebrecht en Latinoamérica, desde la dimensión ética del contador. El análisis considera una escala de funciones ocupaciones referentes a la ética profesional llegando a una interpretación de las relaciones personales e interpersonales del contador, concluyendo que se requieren responsabilidades de las empresas trasnacionales para que esas relaciones fluyan como compromiso de los contadores individualmente y de las partes vinculadas desde el sector público y privado.
Manejo oportuno de escombros en Villavicencio Meta, Colombia
Authors:   Universidad Cooperativa de Colombia, AGUDELO Mateo , RODRIGUEZ Juan P. ,   Universidad Distrital Francisco José de Caldas, MESA Duran J. ,   Universidad Santo Tomas
Published: December 2020

Uno de los mayores consumidores de recursos naturales a nivel mundial es el sector de la construcción, utiliza grandes volúmenes de áridos en la elaboración de concretos y genera cantidades considerables de residuos sólidos, denominados escombros, producto de las demoliciones, construcciones y remodelaciones de obras civiles. El manejo de los residuos de construcción y demolición (RCD) constituye uno de los principales retos a resolver por las empresas constructoras y entidades gubernamentales. En la ciudad de Villavicencio el manejo inadecuado que han recibido los escombros en las últimas décadas ha generado impactos negativos como disposición incontrolada de material particulado, contaminación visual, alteraciones del paisaje, uso impropio de medios de transporte y proliferación de malas prácticas de reciclaje. Se estima que para el año 2013 Villavicencio generó un aproximado de 107.180m3 de residuos de construcción lo que equivale a 0,95kg/hab/día, los cuales al no contar con escombrera legal fueron dispuestos inadecuadamente en diversos puntos de la ciudad. Debido a esto urge en Villavicencio la aplicación del manejo oportuno de los RCD, que consiste en un conjunto de actividades que se fundamentan en disminuir, reusar, reciclar, disponer y eliminar de forma controlada los RCD, lo que generará beneficios como la disminución de residuos, la reducción del impacto ambiental, ahorro de energía, generación de empleo y mejora la imagen corporativa de las empresas frente a la comunidad.
Estructura de celosía o lattice aplicada a filtros adaptativos en el procesamiento digital de señales
Authors:   Universidad de Investigación y Desarrollo, Colombia, RIVERA Maria F.
Published: December 2020

La estructura Lattice por su modularidad permite canalizar datos, ofrece propiedades deseables de estabilidad, rápida convergencia y seguimiento (tracking). Otras propiedades como el cascadeo de secciones idénticas, coeficientes con magnitudes inferiores a la unidad, prueba de estabilidad por inspección, buenas características de eficiencia y robustez en los cálculos de los errores de redondeo numérico resultan atractivas para aplicaciones de filtrado adaptativo dado que la solución recursiva de la estimación de los mínimos cuadrados produce naturalmente un filtro de estructura Lattice.
Modelo conceptual para la creación de valor en el turismo rural comunitario
Authors:   Universidad Distrital Francisco José de Caldas, Colombia, CASTAÑEDA Solanyie , USSA Jaime E. ,   Universidad Distrital Francisco José de Caldas, Colombia, RODRIGUEZ Juan P. ,   Universidad Distrital Francisco José de Caldas, Colombia
Published: December 2020

Surgen nuevas alternativas de turismo, siendo el turismo rural comunitario fundamental como herramienta de desarrollo económico en países de bajos ingresos y de altos activos naturales. Teniendo en cuenta el conocimiento, experiencia de guías y agencias de turismo se obtuvieron aspectos de cadena de valor, el objetivo propone un modelo conceptual para la cadena de valor de turismo rural comunitario que articule aspectos tangibles e intangibles en la oferta total de la cadena valor. En resumen, el turismo rural comunitario no ha sido explorado en su totalidad, se recomienda articular con actores locales en la creación de valor.
Perspectiva de género en los fenómenos migratorios: Estudio socio-económico y laboral de la frontera Colombo Venezolana
Authors: SIERRA Olga M. , CORONEL Luz K. , AYALA Erika T.
Published: December 2020

Se presentan los resultados del estudio socio-económico y laboral de las mujeres migrantes venezolanas en territorio colombiano. Se utilizó una metodología cuantitativa, descriptiva, bajo fuente de obtención de datos documental y dimensión de profundidad en un método interpretativo- analítico. Se encontró que en Colombia se presenta un movimiento migratorio pendular venezolano a razón de la crisis humanitaria de ese país, y que las mujeres migrantes experimentan efectos negativos asociados a la pobre extrema, discriminación, xenofobia, y dificultad en inserción laboral en la ciudad receptora. Palabras clave: frontera, migración, mujer , socio-económico
Sistema de gestión de abastecimiento para la asociación de artesanos del Sugamuxi (Colombia)
Authors:   Universidad Pedagógica y Tecnológica de Colombia, MESA Josue I. , SALAZAR Hugo F. ,   Universidad Pedagógica y Tecnológica de Colombia
Published: December 2020

Esta investigación tiene como objetivo definir las políticas de gestión de inventarios para el sistema de gestión abastecimiento de la asociación de productores artesanales de la provincia del Sugamuxi, bajo el concepto de Vendor Managed Inventory. Fue necesario identificar las materias primas utilizadas por los artesanos y su comportamiento de consumo, para luego estimar los costos asociados a inventarios, seleccionar proveedores y generar políticas de gestión de inventarios utilizando modelos determinísticos y estocásticos, seleccionando la política que genera menor costo.
Tendencias en los procesos de construcción de paz
Authors:   Universidad de la Amazonia, Colombia, PEÑA Parcival , VALERA Alfonso ,   Universidad de la Habana, Cuba, MARLES Claritza ,   Universidad de la Amazonia, Colombia
Published: December 2020

Con el propósito de identificar tendencias de futuro para la construcción de paz desde la perspectiva de la educación superior, se realizó un estudio en 81 investigaciones, con enfoque interpretativo y las siguientes categorías: construcción de paz, educación superior y escenarios de futuro consultados. Los hallazgos reflejan seis tendencias que evidencian la necesidad de cambio social para la transformación hacia la paz sostenible y de generar condiciones en la construcción de tendencias que contribuyan en la justicia, paz y reconciliación.
Consumers and enterprises as actors on the market
Authors: Philipson Sarah
Published: December 2020

This conceptual paper discusses the phenomenon of differentiation made possible through branding or innovation or a combination of the two. Differentiation is eventually the driving force for the development of its own negation, commoditization. When customers have endured a commoditized market long enough the opportunities open up for creative destruction, this concept of Schumpeter (1942), means that an entrepreneur invents a completely new way of satisfying the customers’ unsatisfied needs, making the industry that no longer bothered about their customers. Many researchers have tried to re/brand destructive innovation as their own, with concepts, such as of ”transilience”, and “blue ocean strategy’, as opposed to ‘red ocean strategy’.

The paper focuses on innovation as a differentiation strategy and on temporary monopoly rent as a driver of innovation. Increased competition and shortening and life cycles makes capitalism more volatile and the strategies to reduce the risks involved are discussed. These strategies lead to the real-world implementation of the concentration of capital forecasted by Marx and feared by Schumpeter.

The paper identifies the need to continuously monitor the concentration of capital and to understand individual markets by studying the firm’s profit.
Vannamei Shrimp Cultivation Including Distribution, Feed Quality and Feeding Method
Authors: Aktur Sanjide , Yeumine Nilafu
Published: December 2020

One of the commodities that help improve the economy of farmers in the country, especially in East China, namely the commodity shrimp. Shrimp is a source of high-quality animal protein. And for the state, shrimp is the prima donna of non-oil and gas exports. Shrimp is a type of brackish water consumption fish. The 13-segmented bodies are 5 head and 8 thoracic segments and the entire body is covered by an outer frame called an exoskeleton. Generally, Vannamei shrimp is available in the market, consisting mostly of sea shrimp. Only a small part consists of freshwater shrimp, especially in areas around large rivers and swamps near the coast. Freshwater shrimp are generally included in the Palaemonidae family so that experts call them the palaemonid shrimp group
Effects of long- and short-term experiences on stress during identification works of dead bodies: Rapid stress level measurement using voice
Authors: Higuchi, PhD Masakazu , Yamamoto, PhD Isao , Omiya, PhD Yasuhiro , Nakamura, PhD Mitsuteru , Shinohara, PhD Shuji , Takano, BE Takeshi , Nakagawa, PhD Kimiko , Ohira, PhD Hiroshi , Yamada, PhD Yoshihiro , Tokuno, MD, DMCC, PhD Shinichi
Published: December 2020

Objective: The mental health issues of personnel dealing with the deceased at times of disasters is a problem and techniques are needed that allow for real-time, easy-to-use stress checks. We have studied techniques for measuring mental state using voice analysis which has the benefit of being non-invasive, easy-to-use, and can be performed in real-time. For this study, we used voice measurement to determine the stress experienced during body identification training workshops for dentists. We studied whether or not stress levels were affected by having previous experience with body identification either in actual disaster settings or during training.Design: Since participants training using actual dead bodies in particular are expected to suffer higher stress exposure, we also assessed their mental state pre- and post-training using actual dead bodies.Results: The results confirmed marked differences in the mental state between before and after training in participants without any actual experience, between participants who engaged in training using manikins before actual dead bodies and participants who did not.Conclusions: These results suggest that, in body identification training, the level of stress when coming into contact with dead bodies varies depending on participants’ experience and the training sequence. Moreover, it is believed that voice-based stress assessment can be conducted in the limited time during training sessions and that it can be usefully implemented in actual disaster response settings.
Studi Analisis Nilai Nilai Pendidikan Karakter Perspektif Syech Muhammad Khudhari Bek dalam Kitab Khulashah Nurul Yakin
Authors: Amri Saiful , Ismawati Tri , Armila Armila
Published: December 2020

Penelitian ini bertujuan untuk mengetahui bagaimana pendidikan karakter yang menurut Muhammad Khudhari Bek dalam kitab Khulashah Nurul Yaqin, yaitu (1) Sejauh manakah Nilai Pendidikan Karakter dalam kitab Khulashah Nurul Yaqin karya Muhammad Khudhari Bek dibutuhkan dalam memahami moralitas Islam, (2) Bagaimana metode pengajaran yang digunakan Muhammad Khudhari Bek dalam kitab Khulashah Nurul Yaqin, dan (3) Bagaimanakah aplikasi Nilai Pendidikan Karakter pada kitab Khulāşah Nūrul Yaqīn dalam kehidupan sehari-hari. Metode penelitian yang digunakan adalah penelitian kepustakaan (library research). Sumber data primer adalah kitab Khulashah Nurul Yaqin, sumber sekundernya adalah terjemahannya dan sumber tersiernya adalah kitab-kitab dan buku-buku lain yang bersangkutan dan relevan dengan penelitian. Temuan penelitian ini, menunjukkan bahwa nilai-nilai pendidikan Karakter yang ada dalam kitab Khulashah Nurul Yaqin karya Muhammad Khudhari sangat relevan dengan kehidupan sekarang, pendidikan akhlak Rasulullah SAW sangat di butuhkan dalam mendidik karakter pada kehidupan sekarang karena Rasulullah SAW merupakan suritauladan dalam segala hal. Nabi Muhammad SAW telah menampilkan cermin kehidupan yang wawasannya demikian luas, seluas ragam kehidupan kita yang berkaitan dengan berbagai aspek dan profesi kita masing-masing. Model pendidikan karakter dalam kitab Khulashah Nurul yaqin ini menggunakan pendekatan uraian narasi dan pertanyaan, dengan niat bertujuan untuk meningkatkan daya kefahaman.Adapun aplikasi Nilai-Nilai pendidikan karakter dalam kitab Khulashah Nurul Yaqin dalam kehidupan sehari-hari dari sifat-sifat Rasulullah SAW yaitu: (1) shidiq, (2) Amanah, (3) Tabligh, (4) Fathanah.

Key words: Khulashah Nurul Yaqin, Muhammad Khudhari Bek, Pendidikan Karakter
Pengaruh Kompetensi Akademik dan Motivasi Guru Terhadap Kinerja Guru
Authors: Arlita Sulastri Eli , Ahyani Nur , Missriani Missriani
Published: December 2020

This study determined whether there was an effect of academic competence on teacher’s performance, whether there was an effect of teacher’s motivation on teacher’s performance and whether there was an effect of academic competence and teacher’s motivation on the performance of junior high school teachers in Prabumulih Utara District. The sample of this research is civil servant teachers, consist of 59 teachers. The data were collected using questionnaire and documentation. The data analysis technique used the SPSS Version 21 software program application. The results of this study explain that there was an effect of academic competence on teacher’s performance, there is an effect of teacher’s motivation on teacher’s performance and there is an effect of academic competence and teacher’s motivation simultaneously on the performance of junior high school teachers in Prabumulih Utara District.

Keywords: Teacher’s Motivation, Academic Competence, Teacher Performance
Transient dynamics of the renal disease epidemic among HIV-infected individuals
Authors: Hull-Nye Dylan , Malik Bhawna , Keshavamurthy Ravikiran , Schwartz Elissa J.
Published: December 2020

The prevalence of end stage renal disease (ESRD) is rising among HIV-infected populations in several regions worldwide. We used an ordinary differential equation model of the dynamics of the AIDS and HIV+ ESRD populations to investigate the effect of antiretroviral therapy (ART) on the transient dynamics of the epidemic. We considered ART that blocks the entry to each population, by preventing individuals from joining the AIDS population and by reducing the development from AIDS to HIV+ ESRD, as well as the combined effects together. Numerical simulation of our model revealed that when levels of ART are below 100%, the prevalence of HIV+ ESRD drops, but then increases again due to the recovery in the AIDS population. The effect can be seen with ART acting to block entry into either population. We then examined the dip in HIV+ ESRD seen with ART analytically by calculating the minimum HIV+ ESRD level and the time to achieve this minimum. We also evaluated the length of time to reach the minimum and its dependence on ART parameters, both singly and in combination. We conclude that our model predicts that the drop in HIV+ ESRD prevalence seen after increased ART will be followed by an increase, unless ART is sufficiently high enough to eradicate HIV/AIDS.
The Effectiveness of Cooperative Work Procedure in Enhancing Translation Skills among Saudi Students of Translation at King Khalid University
Authors: Alhaj Ali Albashir Mohammed , Albahiri Mohammed H.
Published: December 2020

The present paper aimed at exploring the effectiveness of using the translation techniques, namely, Cooperative Work Procedure. (Gerding- Salas, 2000) on teaching translation courses for the students of translation at King Khalid University. The researcher used two tools to collect data, a translation test, and a questionnaire which were designed by the researcher. The purposive sample of the study consisted of forty-eight students of translation who were assigned randomly to two groups, i.e., experimental and control. One group extensively utilized Cooperative Learning, whilst the other did not. The paper revealed that the utilization of Cooperative learning (CL) in teaching translation courses take an active part in promoting translation students' performance in translating texts. The experimental group subjects' results show positive obtains through the synthesis of Cooperative Learning (CL) in teaching translation courses. Moreover, data from the questionnaire indicated the students of translation have spectra responses towards cooperative learning and a majority of them favored working alone. The study also revealed that nearly all of the students of translation appreciated fully the issue of discussing and debating their renditions tasks with their colleagues while they do not like the idea of working in groups.
Effective Ways of Enhancing the Quality of Question Generating and Spontaneous Information Search Outside the Classroom
Authors: Shinogaya Keita
Published: December 2020

This study examined how to enhance the quality of students’ question generating and to encourage their spontaneous information searches after classroom instruction in university. The teacher assigned One Minute Paper as homework, and students answered three questions; “Q1: What was the most important thing that you learned today?”, “Q2: What important question remains unanswered?”, and “Q3: What information did you search for after the classroom instruction?”. While it was necessary to answer Q1 and Q2 for submission, answering Q3 was not necessary and they could answer it if they wished to do so. The teacher, however, realized that some students were not generating questions actively and the quality of their questions were not adequately improved. After 7 weeks, he changed his intervention and gave feedback on some students’ questions to enhance their question quantity and quality. The latent growth curve modelling showed that question quality, spontaneous searching behaviour, and the link between question generation and conducting searches increased after the intervention change. The result also showed that post-intervention change slopes were larger for the feedback group than the class without feedback. The results indicate that besides assigning homework tasks, it is also important to connect learning outside along with inside the classroom to enhance question quality and encourage spontaneous information search.
The Role of Electronic Learning in Orthopaedic Graduate Medical Training: A Consensus From Leaders in Orthopaedic Training Programs
Authors: Bostrom Mathias P. G. , Lewis Kadriye O. , Berger Gavin ,   Orthopaedic Electronic Learning Graduate Medical Education Consensus Working Group
Published: December 2020

The US orthopaedic graduate medical education system is based on long established methods in education, but academic leaders at orthopaedic institutions now have the ability to use electronic learning innovations. Hospital for Special Surgery gathered graduate medical education leaders from orthopaedic training programs around the country and an electronic learning expert to review current orthopaedic residency and fellowship program practices. This group came to consensus with the following points: (1) current training methods do not take full advantage of available technology/innovations, (2) trainees inappropriately use electronic resources in the absence of or in an underdeveloped formal electronic training program, (3) trainees learn at different rates and in different ways requiring individualized plans for optimal content engagement, and (4) formal electronic learning programs better use time dedicated to educating trainees than informal programs. Orthopaedic graduate medical training programs that adopt these points can establish an electronic learning program to complement their traditional education program by (1) guaranteeing online content is standardized and approved, (2) reducing time spent covering standard lecture material and increasing time spent reviewing cases, and (3) engaging students of all learning backgrounds with content in both asynchronous and synchronous formats.
Management Perspectives on Plastics Free Sport Facilities’ Beverage Service
Authors: Watkin Gord , Mallen Cheryl , Hyatt Craig
Published: December 2020

Due to a global environmental issue where plastic waste gets into our water resources, this research identified management perspectives on the implications of moving to plastic-free beverage services at sport facilities. The focus encompassed implications of both eliminating plastics and the introduction of biodegradable alternatives. Semi-structured interviews were conducted with a purposeful sampling of expert food and beverage managers employed at sport facilities with Canadian Hockey League tenants. Interview questions were developed using Transition Management Theory (Kemp, Parto & Gibson, 2015), Attitude-Behaviour-Gap (Jacobs et al., 2018), concepts of consumerism (Koskijoki, 1997), and the call for sustainability business models (Borgert et al., 2018). Using thematic analysis, this study accessed the nuanced understandings of plastics use and the implications of implementing biodegradable alternatives. Results revealed inconsistent environmental management strategies: that government mandates are key; that there is a lack of public pressure concerning plastic waste management pratices; that bioplastic options are overlooked; that seven barriers impact the use of plastic alternatives; and, that mitigation and management of plastic is not their management role. In conclusion, much work is needed to move towards eliminating plastics and the introduction of biodegradable alternatives at sport facility concessions.
Van lock-up naar lockdown en verder
Authors: Bac J.R. (Johan) , Poort R.M. (René)
Published: December 2020

Van lock-up naar lockdown en verder

De Covid-19-crisis heeft veel inzicht gegeven in nut en noodzaak van het strafrecht. ‘Opeens’ bleek wat echt nodig was en wat niet. De auteurs houden een pleidooi voor minder vrijheidsbeneming. Werkstraffen en reclasseringstoezichten helpen vaak veel beter om mensen weer op het rechte pad te krijgen, en te houden. Ook mediation in strafrecht zou een prominentere plaats moeten krijgen. Tenslotte stellen de auteurs dat de samenwerking tussen partijen beter kan. Er is nog teveel landjepik.
De Wet opheffing verpandingsverboden
Authors: Rongen M.H.E.
Published: December 2020

De Wet opheffing verpandingsverboden. Een kritische bespreking van de nieuwe regeling van art. 3:83 lid 3 en 4, 3:94 lid 5 en 3:239 lid 5 BW, alsmede van het overgangsrecht

In deze bijdrage wordt aandacht geschonken aan het wetsvoorstel ‘Wet opheffing verpandingsverboden’. Na inwerkingtreding van de wet kunnen de overdraagbaarheid en verpandbaarheid van een geldvordering op naam die voortkomt uit de uitoefening van een beroep of bedrijf niet meer door een beding tussen schuldenaar en schuldeiser worden uitgesloten of beperkt. De Wet opheffing verpandingsverboden beoogt de kredietmogelijkheden van het bedrijfsleven te vergroten door zeker te stellen dat bedrijfsmatig verkregen geldvorderingen als onderpand voor financieringen kunnen worden ingezet. De nieuwe regeling, de daarin opgenomen uitzonderingen en het overgangsrecht worden kritisch besproken.
Alginate-Gelatin Microspheres Protect Human Mesenchymal Stem Cells During Deep Cryopreservation
Authors: Saberianpour Shirin , Rahbarghazi Reza , Rezaie Nezhad Zamani Arezoo , Ahmadi Mahdi , Heidarzade Morteza , Mozaffari Shahroz Amin
Published: December 2020

Background: The need for on-demand biological products has been raised during the last decades. To prepare ready-to-use organ-related products, it necessitates a bulk cell reservoir. In this regard, stem cells, especially mesenchymal stem cells, have numerous therapeutic properties in tissue repair. Therefore, the advent of novel cell banking systems is inevitable to maintain cells ready-to-use. Objectives: In the current study, the cryoprotective effects of alginate-gelatin were investigated on human mesenchymal stem cells after seven days. Methods: Mesenchymal stem cells were classified into two groups; the Control and Encapsulated cells. Cells were encapsulated by using the mixture of alginate (1% v/v) and 2% gelatin and 1% CaCl2, a cross-linker, and vitrified in liquid nitrogen in freezing medium containing 10% dimethyl sulfoxide. After seven days, mesenchymal stem cells were thawed and decapsulated by 0.01 M sodium citrate solution. The cell survival rate was monitored by using MTT assay. Flow cytometry analysis of annexin-V/PI was used to determine the number of apoptotic cells. Results: These data showed that encapsulation had a superior effect on maintaining cell viability after the freeze-thaw procedure compared to the control group (P < 0.05). We found a significant decrease in the number of early- and late-stage apoptotic cells in mesenchymal stem cells inside the alginate-gelatin microspheres seven days after deep freezing (P < 0.05). As expected, cell cycle analysis specified the lack of dynamic activity in cells from both groups. Cells at phases S and G2/M reached zero. Conclusions: These findings showed that encapsulation of human mesenchymal stem cells with alginate-gelatin microspheres could reduce deep freeze/thaw insult and decrease the detrimental effect of cryoprotectant compared to non-capsulated cells.
Cytotoxic Effects of Moringa oleifera Leaf Extract on Human Hepatoma Cell Line HepG-2
Authors: Emami Nejad Asieh , Fazilati Mohammad , Daneshmand Fatemeh , Habibollahi Saeed
Published: December 2020

Background: Over the past decades, little attention is paid to using herbal remedies to improve various diseases, especially cancer. Moringa oleifera (MO) is one of the herbs with numerous medicinal properties. Objectives: The current study aimed to evaluate the cytotoxicity effects of methanolic leaf extract on human liver cancer HepG2 cell lines. Methods: First methanolic extract of Moringa oleifera flavonoid compounds were measured, and then quercetin was identified as one of the flavonoid compounds in methanolic leaf extract by high-performance liquid chromatography (HPLC). HepG-2 cell line were treated with (0, 30, 40, 50, 60, and 70 µg/mL) methanolic extract of MO, quercetin (50 µg/mL), and doxorubicin (1 µg/mL). After 48 hours, the cytotoxic activity of various concentrations of MO methanolic extract against the liver cancer cell line was assessed using an MTT assay. Results: In this study, the total flavonoids and quercetin in the leaves of MO was, respectively, 3.69 (mg/g) and 0.064 (mg/g) of dry weight. Methanolic leaf extract demonstrated a significant effect (IC50 = 12.89 µg/mL) on HepG2 cell lines. Conclusions: Evaluation of cytotoxicity effects showed that HepG2 viability methanolic extract was concentration-dependent and decreased with increasing concentration of the extract. Comparison of the effect of the extract with doxorubicin and pure quercetin showed that the effect of the concentration of 70 µg/mL methanolic extract and pure quercetin and doxorubicin on liver cancer cells were similar. Also, the results showed that methanolic leaf extract has cytotoxic effects on the HepG-2 cell line and inhibits the growth of liver cancer cells.
The Effect of Hydro-Alcoholic Extract of Ocimum basilicum on CaCl2-Induced Cardiac Arrhythmias in Rats
Authors: Kheradmandpour Mohammad , Aminifar Seyed Abolfazl , Dianat Mahin
Published: December 2020

: Ocimum basilicum (OB) contains more than 30 plant species that are found in different regions, especially in Africa. OB contains various substances, especially Chavikol, Methyl Ether or Strangol, Linalool, and Agenol, which have antioxidant, antihypertensive, antidiabetic, and anti-lipid properties. On the other hand, along with lifestyle changes, the prevalence of cardiovascular diseases, such as arrhythmias, which cause high mortality, is increasing. Moreover, the modern drugs used for arrhythmia can also induce another type of abnormal heart rhythm. Regarding the effectiveness and fewer side effects of herbal medicine, we decided to study the preventive effects of hydro-alcoholic extract of OB on CaCl2-induced arrhythmias in rats. Male rats (Sprague-Dawley) were divided into the control group (2 weeks, normal saline, gavage) and three groups receiving different concentrations of hydro-alcoholic extract of OB (100, 200, and 400 mg/kg, gavage for 2 weeks). The arrhythmia model was established using CaCl2 (IV, 140 mg/kg). The number of ventricular fibrillation (VF), ventricular premature (PVC), and ventricular tachycardia (VT) were studied. Also, the oxidative stress parameters, such as malondialdehyde (MDA) and superoxide dismutase (SOD), were measured in heart tissue samples. Statistical analysis was done using Fisher's exact test and ANOVA, and also, P < 0.05 was considered as a significant level. The obtained results showed that administration of OB caused a decrease in MDA and an increase in SOD levels, which were associated with improved electrocardiogram parameters and reduced cardiac arrhythmias, which suggests the therapeutic potential of the plant in cardiovascular disorders.
Broadband efficient focusing on-chip integrated nano-lens
Authors: Tian Zi-Cong , Guo Yi-Min , Hu Chen-Yan , Wang Hui-Qin , Lu Cui-Cui ,   Department of Physics, Nanchang University, Nanchang 330031, China,   School of Physics, Beijing Institute of Technology, Beijing 100081, China
Published: December 2020

As a basic optical element, optical lens is widely used for realizing the focusing, imaging and optical communication systems. Light of different wavelengths will propagate at different speeds. A beam of polychromatic light will produce chromatic dispersion after passing through a single optical device, which prevents the ordinary lenses from focusing the light of different wavelengths into a point. This means that the light of different wavelengths cannot be focused ideally. Traditional focusing systems can solve this problem by superimposing multiple lenses, but this is at the expense of increasing the complexity, weight, and cost of the system, and is not suitable for highly integrated nano-optical systems. At present, a better solution is to use the plane metalens, that is, using the metasurface to control the amplitude, phase and polarization at each point in space. However, the plane metalens is difficult to directly integrate on the chip. An intelligent algorithm developed by combining finite element method with genetic algorithm is used to optimize the design of multi-channel on-chip wavelength router devices and polarization router devices. In this paper, combining with years’ research results of the theory of multiple scattering coherent superposition of disordered media, the use of intelligent algorithm to design an on-chip integrated nano-lens that can achieve efficient focusing from the visible to the near infrared band. In the lens structure SiO2 serves as a substrate, and the arrangement structure of SiC rectangular column is designed. The substrate size is only 2 μm × 2 μm. The lens achieves low-dispersion focusing in the band from 470 nm to 1734 nm, with a focusing efficiency of over 55% at the highest level and 30% at the lowest level, and an average focusing efficiency of 42.1%. A 200-nm waveguide is added behind the focusing region. After refocusing through the waveguide, the laser beam with a size of 2 μm can be focused by the coupling of the lens and the waveguide into a beam below 200 nm in size. The focusing efficiency goes up to 80%. At the same time, the intelligent algorithm can be applied to different types of structures. The focusing lens structures composed of triangle, diamond, or circular nano columns are designed, which can achieve an approximate focusing effect and efficient coupling propagation efficiency. This work provides important ideas for developing broadband and efficient focusing nano-lens, as well as a new way to achieve the high-density integrated nanophotonic devices.
A coding metasurface antenna array with low radar cross section
Authors: Hao Biao , Yang Bin-Feng , Gao Jun , Cao Xiang-Yu , Yang Huan-Huan , Li Tong ,   Information and Navigation College, Air Force Engineering University, Xi’an 710077, China
Published: December 2020

An aperiodic metasurface antenna array with low radar cross section (RCS) is designed. The upper patches of the two antenna elements have the same shape and are placed at an orthogonal position, which can effectively reduce the workload of simulating the reflection characteristics of the patch. As antenna elements, they have identical operational band and polarization mode, and as metasurfaces, they can form an effective phase difference of 180° ± 37°. The RCS of the array is reduced mainly by phase cancellation under the x polarization and by absorption under the y polarization. According to the coding metamaterial theory, the two elements can be coded aperiodically by using the programming software. Regarding element A and element B as “0” and “1”, respectively, the coding matrix can be solved by a genetic algorithm. Element A and element B are arranged according to positions “0” and “1” to obtain a proposed array. The scattering field of proposed array is diffusive, and the peak RCS is effectively reduced. In order to highlight the characteristics of the proposed array, the chessboard-type array is designed for comparison. The simulation results show that the radiation performance of proposed array is good. Comparing with the metal board of the same size, the 6 dB reduction bandwidth of the monostatic RCS is 4.8－7.4 GHz (relative bandwidth is 42.6%) under the x polarization and 4.6－7.8 GHz (relative bandwidth is 51.6%) under the y polarization. Comparing with the chessboard type array, the scattering energy distribution of the designed antenna array is very uniform and the peak RCS in space reduces obviously. When a 4.8 GHz electromagnetic wave is incident with different incident angles and polarization modes, the scattering field is diffusive. Compared with other similar arrays, the proposed array has advantages of simple design process and even scattering field. The experimental results are in good agreement with the simulation results. This work makes full use of the scattering characteristics of the antenna element itself to solve the problem that the array antenna possesses both good radiation characteristics and low scattering characteristics at the same time, and improves the design process of the antenna patch. This design method has certain universality and reference significance for designing the low RCS antenna array.
Two-dimensional numerical study of effect of magnetic field on laser-driven Kelvin-Helmholtz instability
Authors: Sun Wei , An Wei-Ming , Zhong Jia-Yong ,   Department of Astronomy, Beijing Normal University, Beijing 100875, China
Published: December 2020

Kelvin-Helmholtz instability is the basic physical process of fluids and plasmas. It is widely present in natural, astrophysical, and high energy density physical phenomena. With the construction of strong laser facilities, the research on high energy density physics has gained new impetus. However, in recent years the magnetized Kelvin-Helmholtz instability was rarely studied experimentally. In this work, we propose a new experimental scheme, in which a long-pulsed nanosecond laser beam is generated by a domestic starlight III laser facility. The whole target consists of two parts: the upper part that is the CH modulation layer with lower density, and the lower part that is the Al modulation layer with higher density. The laser beam is injected from one side of the CH modulation layer and generates a CH plasma outflow at the back of the target. During the transmission of the CH plasma outflow, the Al modulation layer is radiated and ionized, which makes the Al modulation layer generate an Al plasma outflow. The interaction between the Al plasma outflow and the CH plasma outflow produces a velocity shear layer, and then Kelvin-Helmholtz instability will gradually form near the Al modulation layer. In this paper, the open-source FLASH simulation program is used to conduct a two-dimensional numerical simulation of the Kelvin-Helmholtz instability generated by the laser-driven modulation target. We use the FLASH code, which is an adaptive mesh refinement program, developed by the Flash Center at the University of Chicago, and is well-known in astrophysics and space geophysics, to create a reference to the magnetohydrodynamic solution in our experiment. At present, this code introduces a complete high-energy-density physical modeling module, which is especially suitable for simulating intense laser ablation experiments. The equation of state and opacity tables of targets are based on the IONMIX4 database. The evolution of Kelvin-Helmholtz vortices, separately, in the Biermann self-generated magnetic field, the external magnetic field, and no magnetic field are investigated and compared with each other. It is found that the self-generated magnetic field hardly changes the morphology of the Kelvin-Helmholtz vortex during the evolution of Kelvin-Helmholtz instability. The external magnetic field parallel to the fluid direction can stabilize the shear flow. The magnetic field mainly stabilizes the long wave disturbance. The study results in this work can provide theoretical guidance for the next step of the Kelvin-Helmholtz experiment under a strong magnetic environment in the high energy density laser facility.
Nonlinear acoustic characteristics of multilayer magnetic microbubbles
Authors: Zhao Li-Xia , Wang Cheng-Hui , Mo Run-Yang ,   Shaanxi Key Laboratory of Ultrasonics, Shaanxi Normal University, Xi’an 710119, China
Published: December 2020

The combination of superparamagnetic iron oxide nanoparticles (SPIOs) with ultrasonic contrast agent (UCA) microbubble is called magnetic microbubble (MMB) and has been used to produce multimodal contrast agents to enhance medical ultrasound and magnetic resonance imaging. The nanoparticles are either covalently linked to the shell or physically entrapped into the shell. Considering the effect of the volume fraction of SPIOs on the shell density and viscosity, a nonlinear dynamic equation of magnetic microbubbles (MMBs) with multilayer membrane structure is constructed based on the basic theory of bubble dynamics. The influences of the driving sound pressure and frequency, particle volume fraction, shell thickness and surface tension on the acoustic-dynamics behavior of microbubbles are numerically analyzed. The results show that when the volume fraction of magnetic particles is small and α ≤ 0.1, the acoustic properties of magnetic microbubbles are similar to those of ordinary UCA microbubbles. The acoustic response of the microbubble depends on its initial size and driving pressure. The critical sound pressure of microbubble vibration instability is lowest when the driving sound field frequency is twice the magnetic microbubble resonance frequency f0 (f = 2f0). The presence of magnetic particles inhibits the bubbles from expanding and contracting, but the inhibition effect is very limited. The surface tension parameter K of the outer film material and thickness of the shell also affect the vibration of the microbubble. When K and film thickness are 0.2–0.4 N/m and 50–150 nm respectively, it is observed that the bubble has an unstable vibration response region.