bluuebunny/crossref_metadata_2025 huggingface dataset:
A Conceptual Mission Architecture of a Robotic Spaceflight to Enceladus for Enabling Exploration of its Surface and Subglacial Ocean
Authors:   Cullen College of Engineering, Sasakawa International Center for Space Architecture, University of Houston, Bannova Olga , Mayorova Vera ,   Bauman Moscow State Technical University, Russian Federation, Pavlyuchenko Veronika ,   Bauman Moscow State Technical University, Russian Federation, Denisov Mikhail ,   Bauman Moscow State Technical University, Russian Federation, Igritsky Vladimir ,   Bauman Moscow State Technical University, Russian Federation
Published: December 2024

Sixth-largest moon of Saturn Enceladus is one of the most promising destinations in the Solar System to search for possible presence of extraterrestrial life. The basis of such assumptions is the confirmed presence of a large accumulation of water around Enceladus South Pole under a layer of newly formed ice of 3 to 5 km thick. In the same region, many cryovolcanic sources have been observed, studying of which can provide understanding about development of life on Earth and searching for life on other planets in the Solar System. The paper presents a conceptual mission architecture to explore Saturn’s moon Enceladus with a possibility of conducting surface and subglacial ocean studies. Proposed mission scientific goals and objectives defined technical requirements and the framework of the project. The project includes developing an automatic interplanetary station for studying the surface of Enceladus and equipment required for a contact study on and under the surface, such as a landing platform, rover, melting plant and floating robotic systems. One of the key tasks of the mission development is a landing site selection. Since the terrain of Enceladus is unknown, the choice of the exact location must be made at the time of landing, if the lander can observe the surface. The landing system proposed in this work is a special composition of a platform landing equipment assembly, which includes a set of collapsible surfaces, fixed landing supports, control and braking systems with low-thrust engines designed within the framework of the project. Proposed in this study is a.subglacial underwater robotic vehicle designed for obtaining the most accurate and detailed information about the composition of the Enceladus Ocean water and a possibility of life there. A melting device powered by a radioisotope energy source melts the ice crust allowing the subglacial robotic vehicle to immerse into the ocean. Using contour heat pipes enables heat transfer to the ice and controls the melting process without conversion into electricity. The proposed mission concept can provide a more complete picture of Enceladus as a celestial body, give a detailed description of its surface, characteristics of the subglacial ocean, and potentially answer the question of the existence of life in the subglacial ocean of Enceladus.

Keywords: Enceladus, Subglacial Exploration, Robotic Transplanetary Mission
Mathematical modelling of dengue fever transmission dynamics in Kenya
Authors: Nyanaro Brian , Kimathi George , Wainaina Mary
Published: December 2024

Dengue fever is one of the diseases emerging in Kenya due to effects of climate change and urbanization. The disease is caused by a family of four flavivirus serotypes DENV 1 to DENV4. A deterministic compartmental model for the dengue fever spread dynamics was developed and utilized to examine dengue fever spread dynamics in Kenya. The model was established to be well-stated mathematically and epidemiologically well-posed through positivity and boundedness analysis. The dengue-free equilibrium state was determined as part of the solution to the system of differential equations defining the spread dynamics. The basic reproduction number was determined through the next-generation matrix and used to confirm the stability of the steady state determined before. The study found that when the basic reproduction number was greater than one, the dengue endemic state dominated the solution of the spread dynamics, while when the basic reproduction number was less than one, the dengue free state dominated the solution, implying the disease died down progressively. Sensitivity analysis of the basic reproduction number was carried out to determine the candidate parameters for an optimal control solution. The study found that the infection rate of susceptible mosquitoes, the survival rate of pre-adult mosquitoes, the natural death rate of mosquitoes, the rate at which mosquito survived the extrinsic incubation stage, and the egg-laying of mosquitoes were the most sensitive parameters of the model.
Humanidades Digitales aplicadas: modelos, reconstrucciones y análisis transdisciplinares
Authors: Díez Platas M Luisa , McGowan Nadia , Santa María María Teresa
Published: December 2024

Introducción al monográfico Humanidades Digitales aplicadas: modelos, reconstrucciones y análisis transdisciplinares.
Adaptation to Flooding in St. Augustine, USA
Authors: Grant Ezekiel , Esteban Miguel , Motoharu Onuki , Voulgaris Gerasimos
Published: December 2024

While sea level rise is usually considered as a problem that will be faced in the future, the cumulative effect of decades of slowly rising water levels have meant that many low-lying communities around the planet are already experiencing an increased frequency in tidal flooding. This includes many communities in the United States, such as the city of St. Augustine, in Florida, which has also been devastated by several hurricanes in the early 21st century. The process of how communities will adapt or relocate is notably complicated, and in the present work the authors outline an improved framework that can help to explain the process which individuals undergo as a consequence of individual stressors caused by climate change. Particularly, the feelings of individuals has so far not been studied in detail, and the authors thus conducted a qualitative analysis of the adaptation response by interviewing 20 individuals in two different neighborhoods of St. Augustine, focusing on how “eco-anxiety” might influence them. The results suggest that adaptation countermeasures have been implemented at the city, and sometimes individual level, though community-level strategies have so far been lagging. While short-term adaptation strategies to flooding might be adequate even if individuals are not aware -or deny- long-term climate change, it is unclear whether long-term adaptation by such retroactive approaches might lead to maladaptation practices.
Configuración del empleador complejo: análisis de los indicadores ponderados por la Suprema Corte de Justicia en Sentencia 99/2024
Authors: Pereira Michelena Sebastián , Brascesco Rodríguez Antonella
Published: December 2024

Se analiza la sentencia 99/2024 dictada por la Suprema Corte de Justicia el 22 de febrero de 2024, que absolvió a uno de los codemandados al determinar que no se configuraba a su respecto una hipótesis de empleador complejo. De esta forma, el presente comentario jurisprudencial pretende delimitar la figura del empleador complejo esbozando los indicios que la Corte considera como elementales para la calificación jurídica de un supuesto de hecho concreto dentro de los contornos de la figura.
Las cuestiones de seguridad y salud incorporadas a la declaración de principios y derechos fundamentales de la Organización Internacional del Trabajo
Authors: Ferrizo Izmendi Arturo
Published: December 2024

El presente trabajo se orienta principalmente al análisis de la renovada Declaración de la Organización Internacional del Trabajo sobre principios y derechos fundamentales en el trabajo acaecido en 2022. La ponencia aborda cuestiones vinculadas con el derecho internacional del trabajo, particularmente en lo que tiene que ver con la significancia de las declaraciones como instrumentos jurídicos exigibles. Se ocupa de analizar el posible impacto de dicho documento oitiano en el ordenamiento jurídico uruguayo, en el marco del análisis de algunos antecedentes legales nacionales que indican una preocupación legislativa constante vinculada a la salud y seguridad laboral. El trabajo deja planteado, finalmente, el desafío de seguir estudiando el tema manera seria y dedicada, con el fin responder a la pregunta: ¿no estamos ante el nacimiento de un nuevo principio de derecho del trabajo relacionado con la salud y seguridad?
Reflexiones sobre posibles tensiones entre el convenio 190 de la OIT y el proyecto de ley del Poder Ejecutivo de 2022
Authors: Benoit Viña Carina
Published: December 2024

El acoso laboral es una problemática compleja y multifacética. Aunque sus manifestaciones han estado presentes a lo largo de la historia, es en las últimas décadas cuando se ha comenzado a nombrar y conceptualizar de manera específica, permitiendo su inclusión en el campo del Derecho y, particularmente, del Derecho Laboral.
El reconocimiento jurídico del acoso laboral ha evolucionado, destacando la importancia de identificar las distintas formas en que puede manifestarse: descendente, horizontal, mixto o ascendente. Este reconocimiento ha sido plasmado en diversas legislaciones y ratificado por instrumentos internacionales como el Convenio Internacional del Trabajo n.º 190, que amplía la protección, y para ello construye un ámbito de tutela subjetiva y objetiva muy amplia.
Una de las principales tensiones en la conceptualización del acoso laboral ha sido la necesidad de determinar si las conductas hostiles deben ser continuas en el tiempo para ser consideradas acoso y la segunda está puesta en los actores que pueden llevar adelante las prácticas hostiles.
En este trabajo nos proponemos analizar el proyecto del Ley que envió en 2022 el Poder Ejecutivo al Parlamento, con el objetivo de reglamentar el Convenio Internacional del Trabajo n.º 190 de la Organización Internacional del Trabajo.
Editorial Volume 8 Number 2
Authors: McKergow Mark
Published: December 2024

This issue of the Journal of Solution Focused Practices covers the second half of 2024. We have three important peer-reviewed articles directly relating to solution-focused (SF) practice in action, .
Analysis of Financial Recording Accounting and Calculation of Cost Production in The Home Industry to Improve The Economy
Authors: Ramadhan
Published: December 2024

This study investigates the significance of financial recording accounting and cost production calculation within home industries as a means to enhance local economies. In rural settings like Kelambir Lima Village, where home-based enterprises play a pivotal role in sustaining livelihoods, understanding the efficacy of financial management practices becomes imperative. Through a comprehensive analysis of existing literature and empirical data collected from home industries in Kelambir Lima, this research assesses the current state of financial recording practices and cost production calculation methodologies. Additionally, it examines the impact of these practices on the overall economic well-being of the community. The findings underscore the importance of implementing robust financial recording systems and accurate cost production calculations to streamline operations, improve decision-making processes, and stimulate economic growth at the grassroots level. Furthermore, the study proposes actionable recommendations and strategies to optimize financial management practices within home industries, thereby fostering sustainable development and prosperity in rural communities
Analysis of the Factors Convenience, Design, Trustworthiness, Price, and Various Food Choices on the Intention to Continuously Use Through Perceived Value and Attitude Towards Food Delivery Apps Among Gofood Customers in Manado
Authors: Felicia Veronica Wagiu  , Ronald  , Amelia
Published: December 2024

In the current era of the industrial revolution, it has brought about fundamental changes in various area global order of life. This is characterized by the increasing development of innovation and creativity in information technology which is disrupting various aspects of global life, including competition in the economic sector. This disruption can be reflected in rapid changes that provide momentum to make entrepreneurship the front guard of winning global economic competition. Some industries have opportunities for rapid growth while other industries may experience a decline in the rapid development of Information and Communication Technology which has an impact on socio-economic conditions. This concept is a view of the interaction between the development of innovation and technological development which has implications for macro and micro economics. Among the sectors affected are products and services that are being developed, the production, sale or supply of which depends on how far digital technology reaches. In the digital economy, companies offer their services according to special services for special requests or special offers whose offerings are characterized as. This research was appointed to analyze the influence of convenience, design, trustworthiness, price, various food choices towards intention to continue use through perceived value and attitude towards food delivery apps, especially Gofood customers in Manado. The sample used in this research was Gofood customers in Manado based on data from 120 respondents. For data processing and analysis in this research, we use Structural Equation Modeling (SEM) with AMOS 20.0 software as software for processing data. In this research it was found that satisfaction has a positive value towards intention continuously to use so that the higher level of customer satisfaction results in stronger customers using the Gofood application in Manado.
The Role of Financial Performance in Mediating the Effect of Tax Planning and Corporate Social Responsibility on the Value of Property & Real Estate Companies Listed on the Indonesia Stock Exchange in 2020 - 2023
Authors: Najmatu Rahmah Ali  , Dwi Kismayanti Respati
Published: December 2024

The purpose of this study is to find out an overview of how tax planning and corporate social responsibility in Property & Real Estate Sector Companies can affect company value through financial performance as a mediating variable in 2020 - 2023. The data used are financial statements and sustainable reports obtained from  the  Indonesia Stock Exchange website and  the websites of  each company with a total sample of 31 companies and 109 total observations. Panel data regression analysis was selected as an analysis technique to test the research data with the help of Eviews 12 software. The results of the tested hypothesis in the form of tax planning affect company value and financial performance, while corporate social responsibility affects company value and financial performance, as well as a significant influence of financial performance on company value. This study also obtained results in the form of a mediating role of financial performance in relation to corporate social responsibility and tax planning affecting company value
Analysis Of Career Development And Performance Appreciation For BPJS Employment Employees At The Medan City Branch Office And The Medan North Branch Office
Authors: Rizal Ahmad
Published: December 2024

The purpose of this study is to look into how employee performance at BPJS Employment's Medan City and Medan North branches is affected by career development and awards. All 68 employees of the BPJS Employment Medan Kota Branch Office and the Medan Utara Branch Office make up the study's population. A total of 66 respondents' samples were collected. Purposive sampling is the method of sampling that is employed. This study was carried out in 2023. A questionnaire was used to obtain the data. This study employs a quantitative and associative methodology. SPSS version 20.0 was used for data processing. Multiple linear regression was employed as the analysis method. The study's findings indicate that the F-value is 236.992 with a significance of 0.000, the t-value for career growth is 4.805 with a significance of 0.000, and the t-value for incentives is 4.946 with a significance of 0.000. The performance of employees at the BPJS Ketenagakerjaan Medan City Branch Office and the Medan North Branch Office is thus positively and significantly impacted by career development and awards, whether partially or concurrently.
Factors That Influence Purchase Decisions, Product Display, Price, And Promotion (Literature Review of Marketing Management)
Authors: Alya Abiyah Surya  , Winda Zylvi Faradilla  , Alyaa Jacynda  , Naura Shadiqah Wibowo  , Sabrina Nuraeni  , Ni Nyoman Sawitri
Published: December 2024

This study examines the factors that influence consumer purchasing decisions in the retail sector, focusing on product display, price, and promotion. In an era of increasingly competitive business, companies need to develop effective marketing strategies to attract consumer interest. Through a literature review, this study shows that attractive product displays can increase purchasing interest, while competitive prices and appropriate promotional strategies, such as discounts and cashback, play an important role in influencing purchasing decisions. Although many studies show a positive relationship between price and purchasing decisions, there is variation in its influence which emphasizes the need for further research. The results of this study are expected to provide new insights for retail business actors in formulating more relevant and effective marketing strategies, as well as increasing competitiveness in a competitive market
CONCENTRACIÓN DE QUITINA EN ESPECIES DEFOLIADORAS (Zadiprion ssp.) DE Pinus EN LA SIERRA NORTE, OAXACA
Authors: Suarez Mario , Velasco-Paz Carlos Alberto , Luna-Bautista Lizbeth , Bautista-Juárez Irene , Hernández-Portilla Luis Barbo , Santiago Juárez Waldo , Santiago-García Wenceslao
Published: December 2024

El género Zadiprion incluye insectos defoliadores de gran importancia, debido a que presenta un estatus de plaga esto aunado a las grandes infestaciones que provoca perdida de bosques. El conocimiento escaso que se tiene del comportamiento y la forma de su distribución es una limitante para tomar medidas de prevención o control contra el ataque de estos insectos defoliadores. El objetivo del presente trabajo es caracterizar la composición química y concentración de quitina en la cubierta de la pupa de especies defoliadoras de pinos registrada en la Sierra Norte del estado de Oaxaca. Se determinó la composición química de Zadiprion sp. mediante una digestión química y el uso de espectroscopia de infrarrojo con transformada de Fourier (FTIR). Los resultados que se obtuvieron permitieron hacer una determinación de la composición química de Zadiprion sp. en las diferentes etapas de su ciclo de vida (mosca, larva y pupa).
DESARROLLO FENOLÓGICO DEL CULTIVO DE MALANGA EN CONDICIONES DE INVERNADERO
Authors: Garay-Peralta Ignacio , Herrera-Aalrcón Jesús , Díaz-Criollo Alfredo , Domínguez-Vazquez Marlén Daniela , Garza-Ortega Jesús Alberto
Published: December 2024

El cultivo de malanga (Colocasia esculenta L. Schott) es una planta originaria del sur de Asia, que ha ganado importancia en regiones tropicales de América debido a su alto valor nutritivo y a su potencial comercial. En México, la producción se concentra en el estado de Veracruz, principalmente en los municipios de Actopan y Úrsulo Galván. El presente estudio se llevó a cabo en el Instituto Tecnológico de Úrsulo Galván, con el objetivo de evaluar el desarrollo fenológico de la malanga bajo condiciones de invernadero. Se utilizaron 200 plantas en un diseño experimental de Bloques Completos al Azar, evaluando cuatro tratamientos con y sin acolchado plástico más foliares y sin ellos. Las variables analizadas incluyeron altura y diámetro del tallo, así como peso del propágulo, realizando un ANOVA y para determinar si existe diferencia estadística, se aplicó una prueba de comparación de medias por Tukey α 0.05. Los resultados indicaron que los propágulos provenientes de parcelas comerciales mostraron una adecuada adaptabilidad y desarrollo en condiciones controladas, siendo viables para su uso en sistemas productivos. No se encontraron diferencias significativas en el diámetro del tallo, pero sí en la altura de los propágulos. Se concluye que la malanga cultivada en invernadero representa un potencial para su comercialización y expansión agrícola en zonas tropicales. Se sugiere continuar con investigaciones adicionales para optimizar las prácticas de cultivo y mejorar la calidad de los propágulos.
¿Mujeres travestidas, heroínas o piratas?: una comparación entre Anne Bonny, Mary Read y Hannah Snell a través de la literatura y el grabado en el siglo XVIII
Authors: Echevarría Hernández Judit , Hernández Socorro María de los Reyes
Published: December 2024

Desde finales de la pasada centuria las piratas Anne Bonny y Mary Read han formado parte de una larga tradición de mujeres en el mar que han compartido rasgos elementales como el travestismo y la violencia. En aras de demostrar la singularidad de las piratas frente a otros personajes de este colectivo hemos realizado una comparación entre estas y Hannah Snell, la mujer soldado más notable del siglo XVIII. Para ello hemos analizado las obras que contienen las biografías de los tres personajes, que son A General History of the Pyrates y The Female Soldier, así como algunos de los grabados que las representaron en la centuria. De esta manera, hemos comprobado que las piratas encarnaron, aunque de manera no intencionada, un modelo de feminidad basado en una inusual libertad proporcionada por su singular barco y tripulación, opuesto al rígido papel masculino que Hannah Snell tuvo que adoptar como soldado de Inglaterra.
Palabras clave: mujer pirata, travestismo, Inglaterra, biografía, grabado
SYNTHESIS OF THERMOPLASTIC POLYURETHANE USING AROMATIC DIOLS AS A CHAIN EXTENDER AND DEVELOPMENT OF ADHESIVE COMPOSITIONS BASED ON IT
Authors: Bakirova Indira N. , Mineeva Tatiana A.
Published: December 2024

Thermoplastic polyurethane based on oligobutyleneglycoladipinate, 4,4'-diphenylmethanediisocyanate and a chain extender has been synthesized, as which it is proposed to use aromatic diol - 2,2-bis-[4-(2-hydroxyethoxy)phenyl]propane. The synthesis was carried out in a one-step method with a ratio of reagents providing a lack of isocyanate groups. The final product was a linear copolymer with terminal hydroxyl groups. To compare properties using a similar technology, a thermoplastic was obtained in which the role of the chain extension was performed by aliphatic diol - 1,4-butanediol. The sample obtained with the participation of aromatic diol is amorphous, low-modulus and there is no residual deformation after rupture. The use of aliphatic diol leads to the formation of a crystallized high-modulus polymer with high residual deformation and hardness. The observed differences are associated with the introduction of side methyl groups and simple ether bonds into the structure of a rigid polymer block formed by an aromatic diol. The latter violate the ordering of the packaging of macromolecules and increase their ability to elastic recovery. In addition, the content of aromatic fragments in the hard block increases due to the use of aromatic diol. They contribute to the amorphization of the polymer, increase its strength, and also increase the temperature of the beginning of destruction and the coke residue. At the same time, the thermoplastics under discussion are inferior to the analog synthesized using aliphatic diol in terms of temperatures corresponding to the half-life of the decomposition stage and the completion of the decomposition stage. This is due to the presence of in the hard block of the first, relatively non-thermally stable simple ether bonds. On the basis of the proposed thermoplastic, a two-component adhesive has been developed, which, in terms of bonding strength, surpasses household adhesives, which include polyurethane thermoplastic obtained using aliphatic diol.
For citation:
Bakirova I.N., Mineeva T.A. Synthesis of thermoplastic polyurethane using aromatic diols as a chain extender and development of adhesive compositions based on it. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 106-113. DOI: 10.6060/ivkkt.20246711.7040.
INFLUENCE OF CONSUMPTION OF ACIDIFYING AND COAGULATING AGENTS ON THE PROCESS OF SEPARATING RUBBER FROM LATEX
Authors: Pisareva Irina A. , Nikulina Nadezhda S. , Sannikova Natalya Yu. , Misin Vyacheslav M. , Vlasova Larisa A. , Nikulin Sergey S.
Published: December 2024

The presented work is devoted to improving the stage of separating crumbs of emulsion styrene-butadiene synthetic rubber. A comprehensive assessment of the influence of the consumption of the high-molecular cationic reagent VPK-10, the acidifying component and temperature on the process of reducing the aggregative stability of latex dispersion was carried out. The work investigated the effect of the amount of introduced sulfuric acid on the yield of released rubber at temperatures of 0, 20 or 60 °C. Anomalous behavior of the process was discovered when studying the effect of coagulation temperature on rubber yield depending on the amount of added acid. When introducing sulfuric acid in an amount of 15 kg/t of rubber, an increase in temperature required an increase in the amount of added coagulant to achieve complete recovery of rubber. Reducing the amount of sulfuric acid to 10 kg/t of rubber required an increase in the required amount of coagulant. At the same time, the increase in temperature also required an increase in the amount of added coagulant for maximum effect in releasing rubber. A distinctive feature when reducing the dosage of sulfuric acid to 5 kg/t of rubber was the reverse effect of the temperature of the coagulation process. The highest coagulant consumption was achieved not at 1 °C, but at 60 °C. At the same time, the amount of coagulant required for maximum extraction of rubber crumbs from latex decreased with increasing temperature. The change in the temperature regime of the process of separating rubber from latex with a decrease in the acidity of the coagulated system is possibly due to the fact that with a lack of sulfuric acid, incomplete conversion of latex carboxylic acid soaps into carboxylic acids occurs. Therefore, there is no significant destabilization of latex globules and the protective layer based on an anionic surfactant does not undergo global destruction.
For citation:
Pisareva I.A., Nikulina N.S., Sannikova N.Yu., Misin V.M., Vlasova L.A., Nikulin S.S. Influence of consumption of acidifying and coagulating agents on the process of separating rubber from latex. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 114-121. DOI: 10.6060/ivkkt.20246711.7048.
Rh(III) AND Ir(IV)-CONTAINING FILMS BASED ON CHITOSAN AND AGAR-AGAR: DYNAMICS OF CHANGES IN PHYSICAL AND CHEMICAL PROPERTIES
Authors: Godzishevskaya Anastasia A. , Lopashinova Elizaveta P. , Snegireva Anastasia A. , Kurasova Margarita N. , Trifonova Tatiana S.
Published: December 2024

Films based on natural polysaccharides are already widely used in coordination chemistry, medicinal chemistry, environmental chemistry, and pharmaceuticals. The wide range of applications of these materials is due to their high environmental friendliness, biocompatibility and biodegradability. To determine the possibility of using these materials, it is necessary to characterize their physicochemical properties. Chitosan-agar films were obtained by casting from solution with glycerol as plasticiser. The films contain Rh3+ and Ir4+ cations in different ratios of polymer matrix and metal cations. The materials were characterised by IR spectroscopy, differential thermal and thermogravimetric analysis (DTA and TGA), and scanning electron spectroscopy (SEM). In this paper, the dynamics of changes in mechanical properties (short-term strength (N/mm2) over a period of two months from the date of production of the material have been considered. It was proven that the nature of the metal center affects the mechanical properties: rhodium-containing samples are characterized by higher short-term tensile strength than the corresponding iridium-containing ones. The behavior of materials in aqueous solutions is also an important characteristic for determining the possibility of using films. The dynamics of the swelling behavior was studied in water as well as in salt buffer solution (pH=7.2). In buffer solution, the films undergo less swelling than in distilled water. The degree of material swelling with inclusion of rhodium(III) cations is higher than that of films with the same ratio of polymer matrix and iridium(IV) cations. When materials are stored under standard conditions, not only mechanical properties, but also the degree of swelling of the samples change. Over time, the values fall regardless of the composition of the samples under study.
For citation:
Godzishevskaya A.A., Lopashinova E.P., Snegireva A.A., Kurasova M.N., Trifonova T.S. Rh(III) and Ir(IV)-containing films based on chitosan and agar-agar: dynamics of changes in physical and chemical properties. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 63-68. DOI: 10.6060/ivkkt.20246711.7050.
DISPERSED POLYOXADIAZOLE MODIFIER FOR ANTIFRICTION PHENOLFORMALDEHYDE TEXTOLITES
Authors: Panova Mariya O. , Buyaev Dmitriy I. , Shaposhnikova Vera V.
Published: December 2024

Antifriction polymer composite materials based on phenol-formaldehyde resole binders, reinforced with textile-combined polyoxadiazole and cellulose fibers, have high tribological and physical-mechanical properties. This opens up prospects for solving a wide range of problems in the design of friction units of machines and mechanisms with an extended service life.  However, when processing these materials into finished products, technological difficulties arise that limit their use. The use of a dispersed modifier simplifies the technology for producing polymer composite materials. By grinding polyoxadiazole fibers in a ball vibration mill, a new type of anti-friction dispersed modifier of phenol-formaldehyde binders was obtained. In accordance with the data of diffractometric analysis, when grinding polyoxadiazole fiber, there is a slight decrease in its crystallinity, which has virtually no effect on the physical and mechanical properties of the material. The resulting dispersed modifier is a mixture of short fragments of deformed polyoxadiazole filaments and flaky polyoxadiazole particles of irregular shape, the size of which reaches 200-250 µm. X-ray photoelectron spectroscopy data indicate an increase in the nitrogen content in the resulting powdered product compared to the original polyoxadiazole fiber. The introduction of a powdered polyoxadiazole modifier into a phenol-formaldehyde binder for cotton textolites ensured the production of self-lubricating wear-resistant antifriction polymer composite materials with good tribological properties. A decrease in the coefficient of friction, wear and temperature in the friction contact zone is observed (under conditions of dry friction on a steel counterbody). The samples of the studied materials with a small content of polyoxadiazole modifier (5% wt.) in the phenol-formaldehyde binder have the best tribological characteristics. The properties of the resulting materials are due to polymer composite materials reinforced with a fabric combination of fibers, polyoxadiazole and cellulose.

For citation:
Panova M.O., Buyaev D.I., Shaposhnikova V.V. Dispersed polyoxadiazole modifier for antifriction phenolformaldehyde textolites. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 79-85. DOI: 10.6060/ivkkt.20246711.7051.
STRATEGIES FOR THE USE OF IRON-CONTAINING WASTE IN THE PRODUCTION OF HIGH-TECH CHEMICAL INDUSTRY PRODUCTS
Authors: Afineevskii Andrei V. , Prozorov Dmitrii A. , Smirnov Dmitrii V. , Gordina Natalia E.
Published: December 2024

The article provides an overview of various data on red mud as a waste from the processing of bauxite into aluminum. An analysis was made of the prevalence of red mud in the world, the features of its storage and disposal, as well as the possibility of its processing into products and intermediates necessary for the production of various materials. The features of the chemical composition of red mud are given depending on its place of production and storage. An analysis of world practice on the implementation of the possibility of processing red mud using various techniques is presented. Analysis of literature data has shown that there are a large number of scientific groups involved in the processing of red mud into products such as oxides of various metals, the extraction of rare earth and radioactive metals from it, as well as the production of other products that can be used in construction, wastewater treatment, and agriculture etc. In the article, one of the most significant sections is the protection of the environment from the harmful effects of red mud. The achievements of world scientists to minimize such impacts are presented and measures that need to be taken in the future to protect the environment are considered. In addition, one of the important sections of this article is the section devoted to the processing of red mud into catalysts for various reactions, consisting in most cases of transition metals supported on aluminum oxide. This review article will allow us to systematize existing scientific developments on the processing of red mud and can be used as a basis for further study of the possibility of obtaining industrially important products from metallurgical industry waste.
For citation:
Afineevskii A.V., Prozorov D.A., Smirnov D.V., Gordina N.E. Strategies for the use of iron-containing waste in the production of high-tech chemical industry products. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 6-14. DOI: 10.6060/ivkkt.20246711.7111.
SEPARATION OF POLYMETOXYLATED FLAVONE FROM CITRUS FRUIT FLAVEDO EXTRACTS UNDER “MONOMERIC” REVERSE PHASE HPLC CONDITIONS
Authors: Oleynits Elena Yu. , Deineka Viktor I. , Pronin Ivan S. , Deineka Lyudmila A.
Published: December 2024

For the first time, the regularities of retention of six polymethoxylated flavones from orange peel were determined under reversed-phase chromatography on “monomeric” C18 stationary phases. These flavonoids have received recent attention as compounds with unique biological activities, including (supposedly) effects on the development of intractable Alzheimer's and Parkinson's diseases. Sinensetin (3′,4′,5,6,7-pentamethoxyflavone), 3′,4′,3,5,6,7-hexamethoxyflavone, nobiletin (3′,4′,5,6,7,8-hexamethoxyflavone), 4′,5,6,7-tetramethoxyflavone, 3′,4′,3,5,6,7,8-heptamethoxyflavone and tangeretin (4′,5,6,7,8-pentamethoxyflavone) were found in orange flavedo extract. In the HPLC-friendly retention range (approximately retention factors from 2 to 20), the elution order of the six flavones mentioned above was found to remain unchanged for a number of different trademarks of stationary phases. The largest, but not critical, changes in retention order were found when using a column with increased activity of residual silanol groups. This allows for peak assignments taking into account literature data. Attention was drawn to the fact that the addition of a methoxy group to the structure of the flavone molecule at positions 3 and 8 leads to an increase in retention, while an unusual increase in retention is observed when a methoxy group is removed from position 3′ in the presence of another methoxy group at position 4′. In this case, the addition of methoxy groups both to positions 3 and 8, and to 3′ is accompanied by a bathochromic shift in the absorption maximum of band I, despite the fact that the electron transition in this case is localized on rings B and C. It has been shown that the use of lipophilicity parameters, logP, which can be calculated using several programs, provides results that can be used with caution when predicting the retention of polymethoxyflavones under reversed-phase HPLC conditions, since not all experimental relationships correlate with the calculated logP.
For citation:
Oleinits E.Yu., Deineka V.I., Pronin I.S., Deineka L.A. Separation of polymetoxylated flavone from citrus fruit flavedo extracts under “monomeric” reverse phase HPLC conditions. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 25-32. DOI: 10.6060/ivkkt.20246712.7057.
EVALUATION OF THE INFLUENCE OF WOLLASTONITE FROM TECHNOGENIC WASTE ON THE PROPERTIES OF A POLYMER COMPOSITE BASED ON POLYTETRAFLUOROETHYLENE
Authors: Danilova Sakhayana N. , Tarasova Praskovya N. , Yarusova Sofya B. , Kapitonova Yulia V. , Osipova Valeria N. , Okhlopkova Aitalina A. , Gordienko Pavel S.
Published: December 2024

The paper presents the results of a study of synthetic wollastonite from boric acid production waste (borogypsum) on the physical, mechanical and tribological properties of polymer composite materials based on polytetrafluoroethylene. Wollastonite was synthesized from borogypsum by its hydrothermal treatment in alkaline medium and subsequent calcination of the obtained precipitate at 900-1000 °C for 1 h. The product with a specific surface area of 1.4 m2/g and a density of 3.06 g/cm3 obtained under the above regimes is characterized by the presence of wollastonite of triclinic modification and the presence of CaSO4 anhydrite. The wollastonite particles are needle-shaped with a needle diameter of ~100 nm. Needle-shaped wollastonite particles are shown to be interconnected and form conglomerates and agglomerates ranging in size from 10 to 70 μm. Particle agglomerates are characterized by a wide unimodal distribution of pores with a maximum of 3.78 nm with conical and slit-like shapes. It was found that the use of wollastonite results in increased wear resistance of polymer composites based on PTFE. Composites filled with 10 and 20 wt.% of wollastonite are characterized by a 700-fold decrease in the rate of mass wear relative to the initial polymer. Physical and mechanical studies of PCM show that the introduction of wollastonite increases compressive strength and modulus of elasticity. However, a decrease in strain-strength parameters was observed. Scanning electron microscopy shows the formation of secondary structures on friction surfaces, which plays a role in the adaptation of the composite to wear. The method of IR spectroscopy of friction surfaces registered the appearance of new peaks corresponding to hydroxyl, carbonyl and carboxyl compounds. This indicates a certain contribution of wollastonite particles to tribochemical processes.
For citation:
Danilova S.N., Tarasova P.N., Yarusova S.B., Kapitonova Yu.V., Osipova V.N., Okhlopkova A.A., Gordienko P.S. Evaluation of the influence of wollastonite from technogenic waste on the properties of a polymer composite based on polytetrafluoroethylene. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 102-112. DOI: 10.6060/ivkkt.20246712.7064.
ATMOSPHERIC PRESSURE DIELECTRIC BARRIER DISCHARGE IN HMDS VAPOR AS A COATING DEPOSITION INSTRUMENT
Authors: Shutov Dmitry A. , Ivanov Alexander N. , Sungurova Aleksandra V. , Ignatiev Andrey A. , Morozova Yuliya N. , Rybkin Vladimir V.
Published: December 2024

The paper demonstrates the possibility of using a dielectric barrier discharge for the deposition of polymer organosilicate films on the surface of glass substrates. A planar barrier discharge of atmospheric pressure was excited in a flow reactor in an atmosphere of (Bis(trimethylsilyl)amine at a fixed flow rate. Helium as the carrier gas was used. The carrier gas and working fluid flow rates were fixed at 45 ml/s and 0.2 ml/s, respectively. The frequency of the dielectric barrier discharge was 50 Hz, the average discharge current was 3 mA at a total power put into the discharge of 24 VA. The deposition time varied in the range of 30–1200 s. It was shown that under the conditions studied, the discharge has a filamentous form. The study of the surface morphology and elemental composition of the deposited film was carried out using scanning electron microscopy and energy-dispersive spectroscopy. Surface wettability was determined by the contact angle method and the method of photofixation of drops. The elemental composition of the deposited coatings indicates the formation of an organosilicon film. The contact angle method for polar (distilled water) and non-polar (diiodomethane, glycerol) liquids showed that the wettability of the deposited coatings is higher than that of the original substrate. Additionally, the effect of storage time of deposited coatings (under normal conditions) on their properties was studied. It was found that the storage effect does not have a significant effect on the wettability of the films.
For citation:
Shutov D.A., Ivanov A.N., Sungurova A.V., Ignatiev A.A., Morozova Yu.N., Rybkin V.V. Atmospheric pressure dielectric barrier discharge in hmds vapor as a coating deposition instrument. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 80-85. DOI: 10.6060/ivkkt.20246712.7148.
Pengembangan Produk UMKM Tahu Melalui Pemanfaatan Platform Facebook
Authors: Ngafifudin Asrofi  , Muhamad Rifqi Firdaus  , Bobby Ahmad Fahrezy  , Bintis Tianatud Diniati
Published: December 2024

In this era, many people in Plosokandang Village have not utilized digital technology, even though small businesses play an important role in economic development. One example is Mr. Imin's tofu business. Through a community empowerment program for MSME owners in Plosokandang Village, Tulungagung Regency, entrepreneurs now have more insight into marketing, both offline and through social media such as Facebook. Social media helps them reach a wider range of consumers and meet market demand. The utilization of digital technology allows direct interaction with consumers, obtaining feedback, and adjusting products and marketing strategies. This program is expected to increase the competitiveness of MSMEs in the domestic market while supporting the sustainable strengthening of the community economy. With new skills, MSME owners are expected to be more proactive in facing the challenges of the digital era and support regional economic growth.s
Queen bee egg-laying dynamics: evaluation of Roger-Delon and Warre hives
Authors:   Agricultural Academy, Sofia, Institute of Animal Science – Kostinbrod, Bulgaria, Tsvetanov Tsvetan , Balkanska Ralitsa ,   Agricultural Academy, Sofia, Institute of Animal Science – Kostinbrod, Bulgaria
Published: December 2024

The aim of the present study is to evaluate the egg-laying dynamics of queen bees in Roger-Delon and
Warre hives located in an apiary at an altitude of less than 1000 m. The study was conducted during the active
season of 2023, in an apiary located at an altitude of 860 m in south-western Bulgaria, Pernik district. The bee
colonies were balanced before the beginning of the experiment. Two groups of 6 colonies were formed from
each Roger-Delon and Warre system. Sealed worker brood was measured until the appearance of constant nectar
flow (April – June), and after the appearance of constant nectar flow (September – November). There is currently
a need to examine and quantify the egg-laying dynamics of queens in new hive systems. Queen egg-laying
activity is affected by a variety of seasonal, nutritional and social factors. According to the results obtained, the
average sealed worker brood in Warre hives and Roger-Delon hives are 10484±1031 cm2 and 9564±1057 cm2
(mean±SD) respectively, for the whole period until appearance of constant nectar flow.
Effects of turmeric addition to broiler starter on growth performance, nutrient digestibility, and production economics
Authors:   Department of Animal Nutrition, Joseph Sarwuan Tarka University, Makurdi, PMB 2373, Makurdi, Benue State, Nigeria, Sunmola Taiwo Ayobami , Tuleun Comfort Dooshima ,   Department of Animal Nutrition, Joseph Sarwuan Tarka University, Makurdi, PMB 2373, Makurdi, Benue State, Nigeria
Published: December 2024

The research aimed to assess how feeding broiler chicks’ diets supplemented with turmeric meal
affected their growth performance, nutrient digestibility, and production economics. A four-week feeding trial
was conducted with 120 unsexed day-old Arbor Acres Plus broiler chicks, which were randomly assigned to four
dietary groups, each containing three replicates of ten chicks. The dietary treatments included T1 (control), T2,
T3, T4, and T5, with turmeric inclusion levels of 0%, 0.25%, 0.50%, 0.75%, and 1.0%, respectively. Data were
gathered on growth performance, nutrient utilization, and production costs. Significant differences (p<0.05)
were noted in average daily feed intake (ADFI), ranging from 37.64 to 52.22 g, and feed conversion ratio (FCR),
varying from 1.98 to 2.61. However, dietary turmeric did not significantly impact nutrient utilization across the
groups. The cost of feed per kilogram increased with higher inclusion levels, while T5 demonstrated the lowest
feed cost per chick, as well as for feed cost per weight gain and total production cost. The study concluded
that incorporating turmeric up to 1.0% in broiler diets significantly enhanced feed efficiency without adversely
affecting nutrient utilization. Thus, using turmeric at this level is a beneficial strategy for optimizing production
costs related to feed expenditure per weight gain.
Bibliometric analysis of “Bulgarian Journal of Animal Husbandry” from 1964 to 2023
Authors:   Agricultural Academy, Kostadinova Kristina , Dimitrova Estel ,   Agricultural Academy, Duchev Zhivko ,   Agricultural Academy, Kozareva Boryana ,   Agricultural Academy
Published: December 2024

The aim of this study is to provide a bibliometric analysis of “Bulgarian Journal of Animal Husbandry”
for a period of sixty years (from the first issue, published on 1964, to the last one of year 2023). The data collected
from the titles of each article, authors, their nationality and institutional affiliation, represent the development
of the animal science and scientific periodical in Bulgaria. It also reflects historical and political changes, which
are clearly reflected in the analyzed data set.
Effect of the year on the biological fertility in ewes from a synthetic population of Bulgarian milk with with two consecutive pregnancies in two consecutive calendar years
Authors:   Agricultural Academy, Sofia, Bulgaria, Institute of Animal Sciencs - Kostinbrod, Bulgaria, Metodiev Nikola , Ivanova Tanya ,   Agricultural Academy, Sofia, Bulgaria, Institute of Animal Sciencs - Kostinbrod, Bulgaria
Published: December 2024

The aim of the study is to evaluate the influence of the year on the biological fecundity of sheep from
the Synthetic population Bulgarian milk with two consecutive pregnancies, in two consecutive calendar years.
The study was conducted with 171 ewes, raised in the experimental base of the IAS-Kostinbrod, in the period
2010 - 2021. The first fertilization was between 18 and 20 months of age. Breeding campaigns were conducted
in the period July - September. All animals have had two consecutive lambings, in two consecutive calendar
years. Biological fecundity is determined as a percentage based on the ratio of the number of live births and
stillbirths to the number of lambed ewes. The reffect of the influence of year on fecundity was determined by one-way ANOVA. The effect of factor influence was determined by Fisher’s F-test values. SPSS 21.0 computer
program was used for statistical data analysis. The year had a significant effect on the variation of fecundity in
first lambing ewes from the Sythetic population Bulgarian milk, (F=2.727, P<0.01). The average fecundity of
all studied sheep at the first lambing was 126.90%, and at the second lambing - 122.81%. Ewes that at the first
lambing realize a significant higher fecundity at the second lambing also realize a higher fecundity.