bluuebunny/crossref_metadata_2025 huggingface dataset:
VACUUM BRAZING OF A HIGH-FREQUENCY WAVEGUIDE OF A
RECTANGULAR SECTION AND MINIMAL REFLECTION WITH A
FLANGE
Authors: ISUNTS H.A. , DAVTYAN A.H. , AVAGYAN V. Sh.
Published: April 2023

The technology of vacuum brazing of a long high-frequency waveguide with
variable cross-section and minimal reflection with a flange made of a composite material
based on copper is presented. When developing the technology, experiments were carried
out under different temperature conditions, and materials with different properties were also
used. Oxygen-free copper was chosen as the material for the waveguides. Due to its
properties, oxygen-free copper is easily processed on metal-cutting machines and is widely
used in accelerator technology. The BVAg-8 alloy was selected as the filler, which satisfies
the conditions corresponding to the vacuum brazing process with its composition. Filler is
an alloy of silver and copper. Brazing of a rectangular waveguide and a flange was
performed under high vacuum conditions, in a vacuum brazing unit, which was restored
and modernized at the CANDLE Synchrotron Research Institute.
SUBSTANTIATING THE TECHNOLOGY FOR MANUFACTURING MARAGING STEELS
Authors: AGHBALYAN S.G. , SIMONYAN V.A.
Published: April 2023

As a result of the analysis of domestic and foreign literature, various methods for
producing alloyed metal powders are studied, in particular atomization of alloys, acquisition
with calcium hydride, thermal diffusion saturation, carbonyl processes, electrolysis and
synthesis of complex oxides with further reduction. As a result, it was found that all researched
methods, except for the synthesis and subsequent reduction of complex oxides, are not
suitable for producing maraging steel powders. Atomization is suitable for producing pure
metal powders, production with calcium hydride is impractical because maraging steels
contain metals with a low affinity for oxygen ܨ ,݅ܰ ,݁݋ܥ և ݋ܯ ,thermal diffusion saturation
is not suitable due to the use of metal powder and the carbonyl process is rather complicated
and difficult to implement.
Comprehensive studies have shown that by combining the processes of synthesis
(ferritation) and reduction of complex oxides in the best possible way, it is possible to
develop an effective technology for production of alloyed powders, which will guarantee
acquisition of an ultrapure chemical composition, required structure and properties.
АЛГОРИТМ И ПРОГРАММНОЕ ОБЕСПЕЧЕНИЕ СИСТЕМЫ ИМПУЛЬСНОГО УПРАВЛЕНИЯ СКОРОСТЬЮ СИНХРОННЫХ ДВИГАТЕЛЕЙ
Authors: ГЕВОРГЯН О.Г. , ШИРИНЯН П.А. , КАРОЯН Г.С.
Published: April 2023

Представлены алгоритм и программное обеспечение системы импульсного управления скоростью синхронных двигателей, реализуемой посредством питания статорной обмотки импульсами тока непосредственно от сети через тиристорный коммутатор. Импульсы тока синхронизированы с положением ротора и регулируемы по фазе и величине. Показано, что способ импульсного управления обеспечивает более высокие экономические и качественные характеристики по сравнению с известным
частотным управлением.
THE OUTPUT NOISE REDUCTION OF A LOW-TO-HIGH SUPPLY VOLTAGE LEVEL-SHIFTER
Authors: BABAJANYAN H.A. , KHUDAVERDYAN S.KH.
Published: April 2023

A new approach for reducing output noises in the level-shifter is presented. The
level-shifters which are intended for making the high-voltage amplitude signal from lowvoltage amplitude signal, has a big issue related to the output noises. The noises that come from parasitic capacitances and other sources become much higher in the output as the circuit increases the amplitude of the input signal in the output, so it also increases the
noises. These level-shifters also have the delay time issue. The delay time range between
the input signal and output signal is not so low. Using the capacitances in the output for
reducing the noises can increase the delay time range, which is not a good feature for the
circuit. The new method reduces the output noises without increasing the delay time range, also it increases the area of the circuit with a little percent. By using this method in 32nm technology, the area of the circuit increases by 14% and the noise error decreases by 68%
SOME PECULIARITIES OF THE SCHMITT TRIGGER
Authors: MARTIROSYAN S.G. , TORIKYAN J.E.
Published: April 2023

It has been shown that the use of an additional reference voltage at the input of
Schmitt inverting and non-inverting triggers and an analog switch at the output increases the accuracy of the threshold and output voltages, regulates the position of the hysteresis curve on the horizontal axis. Hysteresis does not depend on reference voltage. General formulas have been derived for determining the threshold values for inverting and noninverting triggers, where the two threshold voltages and the two output voltages, depending on the problem setting, can be positive and negative, or unipolar positive or unipolar negative. Those are presented in the form of the sum of stable and unstable components, by increasing the stable component, it is possible to improve the accuracy of threshold voltage values in classical schemes. The necessity of using additional reference voltage is justified.
In the proposed scheme, the output parameters of the triggers do not depend on the parameters of the microcհip working as a comparator. A guideline of recalculation for increasing the accuracy of threshold voltages using a reference voltage has been developed. A graph is constructed that allows to quickly calculate the relative accuracy increase in the threshold voltages when the reference voltage is applied. This is obtained by increasing the ratio of positive feedback resistances. The reverse problem can also be solved using that graph.
New designations of threshold voltages that facilitate the visual understanding of threshold voltage equations have been proposed.
ECOLOGICAL ASSESSMENT OF THE CONTENT OF HEAVY METALS IN FISH OF THE RIVER IRTYSH
Authors: Artamonov Yu. E. , Klivenko A. N. , Artamonova Ye. N. , Yevlampiyeva Ye. P.
Published: April 2023

The article presents the results of a study of surface waters and fish (perch (Perca fluviatilis L.), carp (Cyprinus carpio L.), bream (Abramis brama L.), pike (Esox lucius L.) of the Irtysh river. The content of Cu and Pb in the organs and tissues of fish living in the Irtysh River within the city of Semey was determined by the ditizon photometric method. The ecological assessment of the results indicates that the concentrations of Cu and Pb in the studied fish specimens do not exceed the MPC. A significant difference in the specific features of the accumulation of heavy metals has been established, depending on the type of fish nutrition and the time of year. The Pb content in various organs of perch, carp, bream and pike ranges from 0.062 mg/kg to 0.083 mg/kg. The highest concentration of Cu is observed in predatory fish (3.27 mg/kg), the lowest – in planktonivores (2.82 mg/kg). Pb also mainly accumulates in pike (0.073 mg/kg). In spring, the content of Pb in the gills of perch and pike increases, Cu – in the gills of bream and pike. The maximum concentrations of Cu in fish were observed in summer, which is associated with an increase in the food supply. The Pb content in summer, on the contrary, decreases due to its adsorption by suspended solids and deposition with them into bottom sediments.
REVIEW OF METHODS FOR DETERMINING THE TONATION OF TEXTS IN NATURAL LANGUAGES
Authors: Nursakitov K. , Bekishev A. , Kumargazhanova S. , Urkumbaeva A.
Published: April 2023

The analysis of sentiment in user comments finds application in many areas, such as evaluating the quality of goods and services, analyzing emotions in messages, and detecting phishing advertisements. There are numerous methods for analyzing the sentiment of textual data in the Russian language, but automatic sentiment analysis of Russian-language texts is much less developed than for other major world languages. This article is part of a broader study on the creation of an information system for detecting dangerous content in the cyberspace of Kazakhstan. The purpose of this article is to provide an analytical review of the different approaches to sentiment analysis of Russian-language texts and to compare modern methods for solving the problem of text classification. Additionally, the article seeks to identify development trends in this area and select the best algorithms for use in further research. The review covers different methods for text data preprocessing, vectorization, and machine classification for sentiment analysis of texts, and it concludes with an analysis of existing databases on this topic. The article identifies some of the main unresolved problems in sentiment analysis of Russianlanguage texts and discusses planned further research.
Միքայել Արուտչյան. կենսագրական և ստեղծագործական ուրվագիծ
Authors:   ՀՀ ԳԱԱ արվեստի ինստիտուտի հայցորդ, Սահակյան Հայկուշ
Published: April 2023

Միքայել Արուտչյանի ժառանգությունը հնարավորություն է ընձեռում առնչվելու գեղարվեստական հոսանքների հետ, որոնք անցյալ դարի առաջին տասնամյակներին թափանցեցին հայկական մշակույթ: Նկարիչն աշխատել է ամենատարբեր ոլորտներում՝ հաստոցային գեղանկարչություն, գրքային և պլակատային գրաֆիկա, բեմանկարչություն, կինոնկարչություն, հեղինակել է մի շարք հոդվածներ, զբաղվել է հասարակական գործունեությամբ: Մեծ է արվեստագետի ներդրումը հատկապես թատերական ձևավորումների և գրքային գրաֆիկայի ասպարեզում. նրա շնորհիվ հայկական բեմանկարչությունը դրվեց պրոֆեսիոնալ հիմքերի վրա, իսկ գրքի ձևավորման հայ բազմադարյան ավանդույթները հարստացան և նոր որակ ստացան: Творческое наследие Микаэла Арутчьяна дает возможность соприкоснуться с художественными течениями, проникшими в армянскую культуру в первые десятилетия прошлого века. Художник работал в различных сферах изобразительного искусства станковая живопись, книжная графика, плакат, сценография, кинематография, писал статьи, занимался общественной деятельностью. Он внес большой вклад в развитие армянского искусства, в частности, в сценическое оформление и книжную графику. Благодаря Арутчьяну армянское театрально-декорационное искусство обрело профессиональную основу, а многовековые традиции армянского книжного искусства обогатились новыми качествами. Legacy of Michael Arutchian allows to associate it with art trends that penetrated into Armenian culture in the first decades of the previous century. The artist worked in various spheres: easel painting, book and poster graphics, scenography, cinematography. He was an author of numerous articles and being active in public activities. The artist had a great contribution especially to theatrical decorations and book graphics. Thanks to him, Armenian scenography developed on a professional basis, and the centuries-old Armenian traditions of book illustration were enriched and acquired a new quality.
Հրաչյա Ղափլանյանը՝ որպես դերասան Երևանի պատանի հանդիսատեսի թատրոնում
Authors:   Երևանի թատրոնի և կինոյի պետական ինստիտուտ, Առաքելյան Ռուզաննա
Published: April 2023

Հայ թատրոնի պատմության նորագույն շրջանի հայտնի ներկայացուցիչներից է բեմադրիչ, ԽՍՀՄ ժողովրդական արտիստ, Երևանի դրամատիկական թատրոնի հիմնադիր-գեղարվեստական ղեկավար Հրաչյա Ղափլանյանը, որը հանրությանը քիչ է հայտնի որպես դերասան: Պատանեկան տարիներին ՊՀԹ-ում անցնելով մասնագիտական հասունացման, թատերարվեստի նրբություններին ծանոթանալու շրջանը` նա այս թատրոնում դառնում է սիրված դերասան, հետագայում նաև՝ բեմադրիչ: Ղափլանյանը պատանիների իր դերերը ներկայացրել է համոզիչ ու հավաստի, հուզիչ ու անմիջական արտահայտչամիջոցներով, խորապես ընկալել հասակակից հերոսների ապրումները, ձգտումները, անձնվեր հայրենասիրությունը և հոգեբանական նուրբ մոտեցմամբ, տրամաբանված խաղով հանդես եկել նրանց հատուկ դրամատիկական դժվար շատ հոգեվիճակներում: Դերասանական տպավորիչ խաղն արժանացել է ժամանակի մասնագիտական մամուլի արժանի գնահատականին: Одним из ярчайших представителей в новейшей истории армянского театра является режиссер, народный артист СССР, основатель и художественный руководитель Ереванского драматического театра Грачья Капланян, который мало известен театральной общественности как актер. Его творческое становление как актера состоялось в стенах Театра юного зрителя, где он постиг тонкости театрального искусства, став любимым артистом, а в дальнейшем и режиссером. Созданные им образы были правдивы, убедительны, непосредственны. Его игра отличалась тонким психологизмом, умением передать душевные переживания своих героев. Актерская деятельность Г. Капланяна была удостоена высокой оценки со стороны театроведов. Hrachya Ghaplanyan, People’s Artist of the USSR, is one of the distinguished figures in the modern period of Armenian theatre history. He was the artistic director and the founder of the Yerevan Drama Theatre. He was known as a famous stage director, but he was less known as an actor to the audience. He started his acting creative way at the Yerevan Theatre of Young Spectator. During this period he underwent psychological school, developed and mastered all the stage skills, traditions and standards on his background, meanwhile improving them. He played the characters of young men of his age, so he knew very well psychological peculiarities of the role and presented the true character of a young man, his behavior, feelings, emotions, aspiration, patriotism. His acting on the stage was highly appreciated by the professional theatrical experts of the time.
Use of the cotton plant (Gossypium sp.) by the community of Caxirimbu, in the municipality of Caxias/Maranhão, as an alternative home remedy
Authors: Santos Luzia Brito dos , Romeu Antonio Vinicius Mendes , Costa Matheus Gomes da , Santos Ismenia Soares dos , Araújo Maria de Fátima Veras , Conceição Gonçalo Mendes da
Published: April 2023

Since time immemorial, humans have established close ties with plants and animals to treat illnesses. Numerous species are involved in various societies that use plants for medicinal purposes, for example cotton. In many cases, the same plant can be used for multiple diseases, and many species can be used individually, and/or in combination to treat a particular disease. The objective of the research was to learn about the use of the cotton plant as medicine by the rural community of Caxirimbu, in the municipality of Caxias, MA. The methodology consisted in the application of a questionnaire, consisting of 10 questions, to the residents of the Caxirimbu community, where the main focus was the elderly, because they make the greatest use of cotton in their daily lives. The results showed that the community hardly ever stops using cotton, since it is a great ally in the treatment of many diseases and few use the health systems (health posts), and the elderly population tends to pass on their knowledge about the plant to their children, and so on. It is inferred that the use of the cotton plant as an alternative treatment has helped many residents, where one of the interviewees reported that at the age of 50 he never needed to use drugs from the pharmacy, as well as others said they only went to the clinic to measure blood pressure, glucose, or get vaccinated.
Analysis of the Human Body's Resistance to AC Voltage
Authors: Kilis Billy , Tuegeh Maickel , Dako Rahmat , Memah Viverdy , Ticoh Janne
Published: April 2023

The economic development of the community affects the widespread use of household electricity. Of course, the development of technology touches every aspect of the activity, whether for entertainment, pleasure or primary needs. Every dry season, the threat of fire is often a scourge for all of us. One of the leading causes is a short circuit of electric current. Electricity is an essential part of this day and age. Everyone needs electricity, whether it is from the lower levels of society to the upper levels of society, both for household, office and industrial purposes. Specifically for household purposes, electricity has become an inseparable part of daily needs. A pandemic has resulted in more extended and varied use of electricity in the home. Another consequence is that it is more prone to short circuits or even fires. The critical criteria that must be met at home are the proper installation of security fuses, the avoidance of sockets with multiple connections, and other items that must guarantee adequate grounding or fulfil the requirements with installations that meet the General Electrical Installation Requirements (in Bahasa Indonesia is abbreviated as PUIL). Problems that can be identified are: What is the average resistance of the student body to AC voltage? Are there any differences in male and female body resistance? The benefits of this research are: Theoretical benefits assessing the average resistance of the human body for planning protection system equipment. Practical benefits it is known as the average student body resistance value. Become a reference in determining the value of a protection system plan. The average measurement results in the range of 5100 Ohm. The results showed a significant difference between the levels of body resistance of male and female students. This is because the number of female students in this study is much smaller than that of male students.
Effect of Workshop Facilities on Practice Learning Outcomes of Students of SMKN 1 Tomohon
Authors: Mohammad Saleh Ainun , Mandagi Gilbert , Kaligis Gery
Published: April 2023

The purpose of the study was to determine the effect of workshop facilities on students' learning outcomes of electrical power installation engineering practice at SMK Negeri 1 Tomohon. The research method used is a quantitative descriptive method with a simple regression technique. The research population was all Class XI students, Department of Electrical Power Installation Engineering, which amounted to 30 people. The research sample was the entire population, Class XI students of the Department of Electrical Power Installation Engineering, which amounted to 30 people. Workshop facilities are one of the external factors that can improve students' learning outcomes of electrical power installation engineering practice at SMK Negeri 1 Tomohon. The formulation of the research problem is whether there is an influence of workshop facilities on the learning outcomes of students' electrical power installation engineering practice at SMK Negeri 1 Tomohon. The research instrument used to measure workshop facilities was a questionnaire, while for student learning outcomes, it was through a learning evaluation. The study concludes that workshop facilities affect the learning outcomes of electric power installation engineering practices for students of SMK Negeri 1 Tomohon. The study results evidence this obtained a significance value of 0.000 <0.05, and the t-count value is more significant than t-table, namely t-count = 11.191 > t-table 2.048. With the magnitude of the influence of 81.7%.
La Enseñanza-Aprendizaje de la Historia en Educación Secundaria. Historia de vida de tres maestras de Tola, Rivas
Authors: Orozco Alvarado Julio César , Fariña Rodríguez Mayela Guadalupe , Almendares Miranda Luis Felipe , Cruz Aguilar Liwdmila Lariza
Published: April 2023

La presente investigación se realizó en el municipio de Tola, departamento de Rivas, con el objetivo de indagar los procesos de enseñanza aprendizaje en la asignatura Historia de Nicaragua, Historia de América e Historia Universal, a través de historias de vida a tres docentes de Educación Secundaria. Esta investigación surge a partir de la necesidad de conocer y valorar la labor de los docentes que impartieron la asignatura Historia. El estudio se basa en el paradigma interpretativo, en este se recopila las metodologías didácticas utilizadas por las docentes de Historia. Es una indagación retrospectiva, se fundamenta en las experiencias docentes, narradas por las maestras en la década que impartieron docencia en la década de los años 90. Para llevar a cabo este estudio se utilizó la Historia Oral como método de investigación y el enfoque de investigación cualitativo, se utilizó la historia de vida como técnica de investigación. Como principales hallazgos se pueden mencionar que en la década de los 90 la enseñanza de las asignaturas de Historia era tradicional, basada en memorización y utilización de libros textos, elaboración de resúmenes e investigaciones en la biblioteca del Centro Escolar. Además, era una educación no gratuita, basada en los preceptos de la “autonomía escolar” y con altos índices de empirismo docente.
Itinerario genético de las relaciones de equivalencia en la escuela y la vida diaria
Authors: Herrera Herrera Arnoldo Abraham , Cisneros Díaz Iván Augusto
Published: April 2023

El concepto de relación de equivalencia describe la práctica prolongada del hombre consigo mismo y con la sociedad, es decir, marca un paso de lo singular a lo plural, una búsqueda entre los objetos o conceptos que poseen algún tipo de correspondencia para luego clasificarlos en equivalentes o no equivalentes. Las relaciones de equivalencia son un producto cultural que han acompañado al hombre en sus diferentes estadios históricos, pero que se vuelve invisible la mayoría de las veces por su cotidianidad, por consiguiente, existen diferentes conceptos matemáticos, que se encuentran aislados por el hecho de no evidenciar su aplicabilidad en la vida diaria. Otro aspecto esencial sobre las relaciones de equivalencia es que figuran como mecanismos imprescindibles para comprender la funcionalidad o comportamiento de diversas cosas que se conjugan en sus similitudes o bien que a partir de sus diferencias muestran aspectos que permiten definirse cierto tipo de relación. En este sentido y bajo la filosofía de mostrar un itinerario del concepto de relación de equivalencia se presentan ejemplificaciones detalladas en diversos contextos y niveles educativos, así como la correspondiente determinación de: clases de equivalencia y conjunto cociente.
Área y Volúmenes de los Sólidos Platónicos
Authors: Herrera Herrera Arnoldo Abraham , Orozco Martínez Ingrid Judith , Cisneros Díaz Iván Augusto
Published: April 2023

Los sólidos platónicos son cinco cuerpos geométricos que comparten un conjunto de características geométricas similares. También reciben el nombre de sólidos perfectos, poliedros platónicos y de cuerpos cósmicos entre otras denominaciones. Los sólidos platónicos son poliedros regulares y convexos dentro de ellos están: tetraedro, cubo (o hexaedro), octaedro, dodecaedro e icosaedro. Este trabajo presenta las deducciones matemáticas de las fórmulas de áreas y volúmenes de los sólidos platónicos. El objetivo central es demostrar el análisis geométrico para obtener las fórmulas de áreas y volúmenes, a su vez reconocer que el estudio de las diferentes técnicas y métodos de demostración permiten aplicar el cálculo de áreas y volumen a la resolución de problemas prácticos que se presentan en diversas situaciones demostrativas de la matemática. Cabe destacar que estas formas de demostraciones están basadas en las propiedades básicas comunes de los objetos geométricos clásicos de la geometría. Por otra parte, el concepto de área y de volumen se generaliza a diversas figuras cerradas permitiendo así una mayor generalidad sobre dichos conceptos para construirse mediante otras estrategias de enseñanzas y aprendizaje. Finalmente, se realiza la programación de dichas fórmulas de áreas y volúmenes en el lenguaje de programación de alto nivel Python, utilizando el paradigma de programación funcional.
Estabilidad del equilibrio de Nash de un juego de Cournot con bienes diferenciados y función de demanda cóncava
Authors: Rojas Rojas Jony , Pérez Avalos Enrique Boanerge
Published: April 2023

En un juego no cooperativo, el beneficio de los agentes involucrados en el juego depende de su función de pago y la estrategia empleada por cada agente. En el caso particular de un juego no cooperativo de Cournot, la elección estratégica de cada agente es la cantidad de bien a producir y su función de pago coincide con la función de beneficio. Este artículo se propuso investigar el equilibrio de Nash y su estabilidad en un juego no cooperativo de Cournot con bienes diferenciados y función de demanda cóncava. El método empleado fue el de la economía matemática y, además, se utilizó una metodología de trabajo que se basa en la revisión bibliográfica, estudio de diversos procedimientos matemáticos y la simulación numérica en el software estadístico R. Como resultado se tiene un nuevo juego no cooperativo bipersonal de Cournot donde la función de demanda es cóncava y se demuestra que este juego tiene un único equilibrio de Nash que, además, es simétrico. Se concluye que, bajo la regla de actualización estratégica de expectativa ingenua, el equilibrio de Nash simétrico es asintóticamente estable y la permanencia en el mercado de las empresas solo es posible si ambas siguen la estrategia de imitación, es decir, cada empresa produce la misma cantidad de bien que su oponente en cada período de tiempo.
Determinar el Índice de sostenibilidad del sistema de agua potable en la comunidad Paso Ancho. Estelí, Nicaragua
Authors: Moraga Marín Mauricio José , Benavidez Markó Richard József , Camas Moreno Yader Alexander , Reyes Aguilera Edwin Antonio
Published: April 2023

La presente investigación tuvo como propósito, determinar la sostenibilidad del sistema de agua potable en la comunidad Paso Ancho del municipio de Estelí. El método que se utilizó es observacional, según su enfoque filosófico es cuantitativo, de corte transversal y de acuerdo a su nivel es descriptivo. Se utilizó la metodología PROPILAS (Proyecto Piloto de Agua y Saneamiento), la cual tiene como propósito validar y sistematizar propuestas bajo concepto de sostenibilidad, evaluando los factores de gestión para la operación y mantenimiento de sistemas de agua potable rurales, a fin de determinar la sostenibilidad de los sistemas. Se obtuvo como resultado del factor estado del sistema una puntuación de 3.2, este se encuentra en el rango de 2.51-3.50 por lo que se les considera en estado regular o medianamente sostenible. La evaluación de la gestión administrativa se determinó una puntuación de 2.23 se encuentra en el rango de 1.51-2.50 esto quiere decir que se encuentra en estado malo y no es sostenible (grave proceso de deterioro). La administración no cuenta con un cronograma de reuniones, no tiene archivos ni expedientes de las modificaciones del sistema, no realizan capacitaciones del manejo del sistema. El puntaje obtenido en el factor de operación y mantenimiento en el sistema fue de 1.83, lo que indica que se localiza en el rango 1.51-2.50 esto quiere decir que se encuentra en estado malo y no es sostenible (grave proceso de deterioro). Se concluye que el índice de sostenibilidad de todo el sistema de agua potable de acuerdo a los factores de sostenibilidad se califica como un sistema medianamente sostenible o en estado regular. El agua que consumen en esta comunidad desde el punto de vista físico-químico es de buena calidad por lo tanto es apta para su consumo humano.
Calidad de aguas marino-costeras en bahías de San Juan del sur, Escameca, La Flor y El Ostional, Costas del Océano Pacifico nicaragüense
Authors: Hurtado-García Iris Lissette , Barberena-Moncada Javier Antonio
Published: April 2023

Las aguas costeras son hábitat de especies marinas y prestan servicios ambientales al ser humano para distintas actividades económicas. El monitorear variables fisicoquímicas, nutrientes en las costas de El Ostional, San Juan del Sur, Escameca y La Flor es de vital importancia debido que es ruta de tránsito de especies marinas y comprender los distintos factores que modifican la composición de las aguas oceánicas en el Pacifico sur de Nicaragua, así también son atractivas para baño y recreación de la población. El objetivo principal de la investigación es determinar la calidad de las aguas marino-costeras mediante las composición fisicoquímica, nutrientes e Indicador de Calidad de Agua Marina (ICAM). Se realizaron dos muestreos en cada sitio, uno en periodo lluvioso 2018 y otro en periodo seco 2019, se tomaron muestras integrales de 20 m de profundidad, variables fisicoquímicas fueron realizadas en sitio y muestras para análisis en laboratorios de nutrientes, microbiológicos. Los resultados indican que el comportamiento fisicoquímico fluctúa según el periodo de monitoreo y la profundidad de medición, las variables fisicoquímicas y nutrientes dependen en primer lugar de la estación lluviosa que aporta nutrientes ya sea por fijación atmosférica o por aporte de escorrentía. Otro factor que influye en la composición química y nutrientes en época seca es las condiciones de altos vientos que producen una surgencia de aguas ricas en nutrientes. No se encontró evidencia de contaminación por bacterias de origen fecal. El índice de calidad de agua ICAM sitúa a las bahías en los rangos de optimo y adecuado, variación que depende de la época en que se monitorea.
Effects of Hydrothermal Alteration and Mineralization on the Paleomagnetic Properties of Rocks from IODP Expedition 376 at Brothers Volcano
Authors: Tontini F. Caratori , Turner G. M. , Reyes A. G. , Speranza F. , Tivey M. A. , Massiot C. , de Ronde C.E.J. , Humphris S. E.
Published: April 2023

The 3-D subseafloor architecture of submarine hydrothermal systems is largely unknown, particularly at arc volcanoes. The alteration of volcanic rocks in these systems produces dramatic changes in their magnetic properties. Here, we present the first comprehensive study of paleomagnetic measurements from oriented samples of hydrothermally altered dacites from Brothers volcano (Kermadec arc), drilled during International Ocean Discovery Program (IODP) Expedition 376. These data have enabled insight into the progressive evolution of magnetic minerals in subseafloor volcanic rocks affected by variable types and degrees of hydrothermal alteration in response to varying fluid temperatures, chemistry, and associated mineralization; from initial chloritization typical of relatively low-temperature interaction with seawater to extremely altered rocks affected by higher-temperature, very acidic magmatic fluids.

Hydrothermally altered samples show a significant reduction in natural remanent magnetization intensity (10–4 to 10–2 A/m) compared with unaltered samples (1–10 A/m), suggesting that primary titanomagnetite grains are destroyed during the hydrothermal alteration process. Except for a small region in proximity to the mineralized stockwork zone, no chemical remanent magnetization is observed in association with hydrothermal alteration, consistent with the widespread formation of diamagnetic and/or paramagnetic minerals such as pyrite, rutile, and leucoxene, which do not carry any natural remanent magnetization.

Demagnetization experiments show that most of the oriented samples possess a stable characteristic remanent magnetization induced by the residual primary magnetic minerals formed at the time the rocks cooled on the sea floor. Partially chloritized dacites, however, are characterized by large magnetic susceptibilities, low Koenigsberger ratios, and very low magnetic coercivities, consistent with initial dissolution of smaller, singledomain magnetic grains, indicating that intensely hydrothermally altered rocks are better paleomagnetic indicators than initially chloritized samples at the periphery of the hydrothermal systems.

The significant magnetic contrast between fresh and hydrothermally altered rocks, in addition to a thick layer (>300 m) of demagnetized rocks observed at Brothers volcano, confirms the empirical results that magnetic anomalies are important geophysical tools to determine the geometry of hydrothermal systems at submarine arc volcanoes.
A Short Story, Reflections, and Thoughts about the Future
Authors: Garrett Margo
Published: April 2023

Margo Garrett's last "Collab Corner" article as inaugural author and manager (2015–2023) of the JOS's first regular column on issues from, about, and for collaborative pianists and the singers who coach, partner, and study with them.
Spring Clean Your Studio Teaching Practices to Optimize Learning
Authors: Maxfield Lynn
Published: April 2023

Celebrity cleaning and organization guru Marie Kondo says that “The objective of cleaning is not just to clean, but to feel the happiness living within that space.” She famously encourages her clients to hold each item in the space they are cleaning and ask themselves, “Does this item spark joy?”. If it does, keep it. If it does not, get rid of it and release it from your life. As the academic year ends and private studios enter summer schedules, now is a great time to re-evaluate our studio time usage. “Pick up” each of our teaching practices and ask the difficult question, “Does this practice spark learning?”.
Pulmonary Function Testing in Singers with Voice Difficulties
Authors: Meenan Kirsten , Sataloff Robert
Published: April 2023

Good respiratory function is a key component of the power source of the voice. If pulmonary (lung) function is impaired, effective support is impaired. Commonly, this leads to compensatory hyperfunction of neck muscles that may result in vocal fold injury. Lung function can be tested easily and safely. When abnormal, treatment is available in many cases.
Singing for Two: A Holistic Review of the Experiences of Classical Singers During Pregnancy
Authors: Gardner Catherine
Published: April 2023

Literature is scant concerning the effects of pregnancy on singers, particularly in terms of the physical, emotional, social, and career implications of singing while pregnant. In this study, singer and voice pedagogue Catherine Gardner summarizes responses of 400 women worldwide to a survey that addressed these issues, with both quantitative and qualitative date documented.
Redes semánticas
Authors: Pérez Ruvalcaba Sara Lidia , Jiménez Macías Ivan Ulianov , Medina Mendoza Eudes Jairo , Andrade Aréchiga Maria , Balcázar Nava Patricia , Castro Valles Alberto , García Avitia César Augusto , Josefa González María Cristina , González Valles María Nieves , Gurrola Peña Gloria Margarita , Gutiérrez González Maria Magdalena , Gutiérrez Pulido Jorge Rafael , López González Ana Lorena , Lozano Martínez Jorge Ramón , Márquez González Claudia Verónica , Pulido Partida Jesus Gamaliel , Rodríguez Morril Evelyn Irma , Vidaña Gaytán María Elena , Villalvazo Núñez Jorge Ricardo
Published: April 2023

En la actualidad, dar cuenta de la vida cotidiana desde la academia exige nuevos retos y formas diferentes de aproximarnos a las realidades de cada uno de los sujetos con los que entramos en contacto. Esto lo podemos hacer desde diferentes lugares, uno de los cuales tiene que ver con la construcción de los significados. Esta exploración puede permitir comprender la relación que se entabla con los demás y consigo mismo, a partir de una serie de operaciones semióticas que posibilitan la flexibilidad de los propios significados y sus modificaciones cuando entran en contacto con los significados de los otros. Este libro plantea en cada uno de sus capítulos una revisión de los significados a partir de las redes semánticas, una técnica par¬ticular que permite, dada su flexibilidad en cuanto a su aplicación y a su rigor metodológico, ser implementada, pensada y reflexionada desde condiciones particulares que obedecen a los diferentes contextos y objetos-sujetos de estudio que se enuncian en este trabajo.
Whole-process Engineering Consulting Services¬ Research on Evaluation of Competence - Nantong Jianchen Engineering Consulting Co., LTD
Authors: Ni Shuangbo
Published: April 2023

At present, with the continuous rapid growth of China's fixed asset investment and the gradual improvement of project construction level, the relatively independent, single and fragmented special consulting mode has been unable to meet the needs of investors or construction units of high quality, high efficiency and low price, and the demand for comprehensive, cross-stage and integrated consulting services is increasing. At the same time, in order to accelerate the development of whole-process engineering consulting services at the government level, relevant departments have issued a series of supporting documents and actively carried out pilot work of whole-process engineering consulting. In this context, this paper takes the whole-process engineering consulting capability evaluation as the research objective, in order to help enterprises find the optimal path for the development of whole-process engineering consulting services. Taking Nantong Jianchen Engineering Consulting Co., Ltd. as an example, this paper firstly introduces the background of the whole process of engineering consulting, and points out the purpose and significance of this research. At the same time, the relevant literature is reviewed and reviewed, and then the ability evaluation system of the whole process engineering consulting service of Nantong Jianchen Engineering Consulting Co., Ltd. is constructed, and the data collected by the questionnaire is analyzed and summarized by this system. Finally, the core improvement strategy of the whole process engineering consulting service of Nantong Jianchen Engineering Consulting Co., LTD. According to the above evaluation results and combined with the actual situation of Nantong Jianchen Engineering Consulting Co., LTD., the corresponding countermeasures for the development of the whole process engineering consulting service are given.
Factors Affecting Women’s Participation in Leadership Position: The Case of Yeka Sub City, Addis Ababa, Ethiopia
Authors: Hailemariam Dagne Tigist , Yang Yong
Published: April 2023

International, continental, and national policies and laws recognize the equality rights of women and take affirmative measures to fill the participation gaps between women and men. However, the actual practice remains untouched so there many factors hinder them from participating in decision-making on various issues concerning their interests in particular and national level at large. Accordingly, this study investigated Factors affecting Women’s Participation in Leadership Positions: The Case of Yeka Sub City, Addis Ababa, Ethiopia. The study applied a qualitative research approach to collect and analyze data from primary and secondary sources. Purposely selected government officials were interviewed; focus group discussions were conducted. Furthermore, various secondary sources of information were referred to. And data were analyzed qualitatively. The findings show that though there are efforts to design legal and policy frameworks like FDRE Constitution and National Women Policy, there are still many factors like attitudes that undermine women’s leadership participation, women’s withdrawal from leadership assignments due to fear of geographical mobility, and separation from, family and patriarchal culture are the major factors that hinder women from participation in decision-making levels. Therefore, the concerned organs should work to make calculated interventions as required and to bring about practical and attitudinal changes to respect the equality rights of women in participation at decision-making levels.
Anticancer Activities of Some Heterocyclic Compounds Containing an Oxygen Atom: A Review
Authors: Abbas Sumayah Saadi , Jasim Azhar Mahdi , Shakir Tayseer Hamid , Abbas Iman Saadi
Published: April 2023

The purpose of this study is to underline the progression and development of research regarding oxygen-containing heterocycles as well as the contribution that some oxygen-containing heterocycles have made as anticancer medicines. A series of publications about the antitumor effects of derivatives of heterocyclic compounds containing an oxygen atom, such as furan, benzofuran, oxazole, benzoxazole, and oxadiazole, were evaluated, and their anticancer activities showed encouraging results when compared to those of established standard treatments.
Estado del arte. Modos de operación y estrategias de control para sistemas de refrigeración solar
Authors: Diaz Juan J. , Fernández José A.
Published: April 2023

El presente trabajo de revisión tiene como objetivo principal proporcionar una visión general sobre los modos de operación y las principales estrategias de control y regulación diseñadas e implementadas para la operación de sistemas térmicos de frio solar, destacando sus principales características, ventajas e inconvenientes. Además, se detallan las condiciones generales de contorno que rigen el funcionamiento de las máquinas de absorción de      LiBr-H2O de simple y doble efecto accionadas por agua caliente, profundizando en los efectos o reacciones que se producen en este tipo de equipos con respecto a las variaciones que puedan ocurrir en las condiciones de funcionamiento del sistema.
Estado del arte. Pinturas fotocatalíticas para la descontaminación del aire
Authors: Franco Yhosmary , Centeno Bordones Guillermo , Pereira Juan
Published: April 2023

En los últimos años, ha surgido un importante interés por la tecnología fotocatalíticacomo alternativa para la descontaminación química y biológica del aire. Los procesos de oxidaciónavanzada (POA) como la fotocatálisis heterogénea es un proceso que se caracteriza por emplear unsemiconductor susceptible a ser activado por radiación ultravioleta-visible (UV/VIS), generandoreacciones redox que son capaces de mineralizar contaminantes ambientales y producir sustancias inocuas.Una de las aplicaciones emergentes de la fotocatálisis heterogénea ha sido la incorporación defotocatalizadores basados en nanopartículas de dióxido de titanio a pinturas arquitectónicas para exteriorese interiores, aportándoles propiedades autolimpiantes, desinfectantes y descontaminantes del aire in situ.Estas pinturas fotocatalíticas son una innovadora tecnología autosustentable, ya que tienen la capacidad deutilizar como fuente de energía la radiación solar o la iluminación artificial de ambientes interiores, para laoxidación de los compuestos orgánicos volátiles (COV), contaminantes en fase gaseosa como el NOx, COx, SOx y la eliminación de microorganismos. Esta revisión muestra las recientes investigaciones enmateria de síntesis, propiedades y aplicaciones de las pinturas fotocatalíticas, así como sus desafíos en ladescontaminación del aire.
تحديد ومكافحة مسبب البياض الدقيقي على نبات الخيار والكوسة في منطقة الوسيطة بالجبل الأخضر
Authors: بوغرسة عيسى علي , الحويطي محمود اكريم , يونس يونس امصادف
Published: April 2023

أجريت هذه الدراسة في معامل أمراض النبات ومزرعة كلية الزراعة ، جامعة عمر المختار ، خلال عروتين متتالين (صيف وخريف) 2003 إفرنجي لتحديد مسبب فطر بياض القرعيات ومكافحته ببعض المتخلصات النباتية في منطقة الوسيطة بالجبل الأخضر . تبين من الدراسة المعملية والفحوصات المجهرية للأجسام الفيروزينية وأنابيب الإنبات في عينة الخيار المصابة بفطر البياض الدقيقي أن المسبب لهذا المرض فطر Sphaerotheca fuliginea ، وتبين من الدراسة والتجارب المعملية أن التركيز %10 من المستخلصات النباتية المستعملة كان ذو فعالية ضد الفطر ويحدث أضرار طفيفة على كلا النباتين ، أما التركيزات العالية كانت ضارة لهما (النباتات والفطر) وتباينت هذه المعاملات معنوياً قبل وبعد العدوى مع الشاهد في نسبة شدة الإصابة على كلا النباتين . وكان أفضلها على نبات الخيار قبل العدوى مبيد التو باز بمتوسط شدة إصابة (%5.08) يليه مستخلص الخردل والثوم (6.60 و %7.72) لكلاهما على التوالي بينما على نبات الكوسة كان أكثرها فعالية مستخلص الخردل بمتوسط شدة إصابة (%5.32) يليه مستخلص الثوم (%6.52) ومبيد التوباز (%8.14) وأقلها فعالية مستخلص الزعتر بمتوسط شدة إصابة (%22.86 و %23.77) على كلا النباتين (الخيار والكوسة) على التوالي . كما اختلف تأثير هذه المعاملات بعد العدوى وتباينت جميعها معنوياً مع الشاهد وكان أكثرها فعالية مستخلص الخردل بمتوسط شدة إصابة (%7.72) على نبات الخيار ومبيد التوباز بمتوسط شدة إصابة (%10.97) على نبات الكوسة ، وأقلها فعالية مستخلص الزعتر (%25.12 و %32.87) على كلا النباتين (الخيار والكوسة) على الترتيب كما لوحظ أن المعاملات (الوقائية قبل العدوى) فعالة في الأسابيع الثلاثة الأولى وتكريرها بعد الثالثة غير فعال في خفض نسبة شدة الإصابة .
Cerebral oximetry and autoregulation monitoring in shock patients
Authors: Lohpratana Jirapat , Viarasilpa Tanuwong
Published: April 2023

Background: Data on regional cerebral oxygen saturation (rSO2) and cerebral autoregulation monitoring in shock patients are limited. This study aimed to find the optimal range of rSO2 and cerebral oximetry index (COx), an autoregulation index correlated with adequate tissue perfusion determined by standard clinical and laboratory assessment.

Method: We plan to monitor cerebral oximetry using near-infrared spectroscopy in shock patients admitted to the medical intensive care unit (MICU) at Siriraj Hospital. The rSO2 are continuously recorded for 72 hours [48] after admission or 24 hours after cessation of vasopressor infusion. The COx is calculated from the correlation coefficient between rSO2 and MAP. Data on patient demographics, treatments, physiologic parameters, and outcomes are recorded. The primary objective is to identify the optimal rSO2 and COx correlated with adequate tissue perfusion assessed by the current standard method. Adequate tissue perfusion as is defined as MAP ≥65 mmHg and two of the following criteria: urine ≥0.5 ml/kg/hour, capillary refill time ≤3 seconds, improvement in consciousness, lactate reduction ≥10% in 1 hour, serum lactate <2 mmol/L, or central venous oxygen saturation (ScVO2) ≥70%. Since the optimal values of rSO2 and COx in shock patients are unknown, we are unable to perform the sample size calculation. Thus, for this study, we plan to collect data on rSO2 and COx in 30 patients.

Hypothesis: We hypothesize that the values of rSO2 and COx are different between patients with adequate and inadequate tissue perfusion.

Ethics statement: The study was reviewed and approved by the Human Research Protection Unit of Siriraj Hospital, Mahidol University (certificate of approval no. si 410/2022).
Support after stillbirth: Findings from the Parent Voices Initiative Global Registry Project
Authors: Ponce Hardy Vicki , Beedle Alexandra , Murphy Sam , Storey Claire , Aggarwal Neelam , Dandona Rakhi , Dev Alka , Doherty Patricia , Heazell Alexander , Kinney Mary , Nam Sara , Quigley Paula , Steen Sue , Vanotoo Linda A. , Leisher Susannah , Blencowe Hannah
Published: April 2023

The need for respectful bereavement care following a stillbirth has been poorly recognised within global public health initiatives. To date, there has been no comprehensive cataloguing of providers that support parents after stillbirth, nor any review of the challenges they face. We aimed to identify providers (organisations and point persons) that support bereaved parents worldwide and to investigate the challenges they face.

A systematic global online search was conducted to identify providers of support after stillbirth. Subsets of providers were surveyed and interviewed. These were purposively sampled to achieve diversity in geography, organisation size and point person role. Challenges in providing support in six key areas – stigma, funding, reach, policy, workforce, and advocacy – were analysed thematically.

Overall, 621 providers from 75 countries were identified. No support providers were identified in 123 countries, and in the 6 countries that carry almost half of the global burden of stillbirths, only 8 support providers were found. Support providers faced challenges in accessing funding, reaching key populations, and training and retaining staff, while complex policies hampered bereavement care. Support providers were challenged by silence and stigma around stillbirth. Overcoming these challenges requires collaboration, effort, and political will at local and international scales.