bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of the effect of altitude on efficiency and emissions of a diesel engine
Authors: Li Zhipeng , Zhang Qiang , Zhang Fujun , Liang Hongbo
Published: October 2023

The Diesel engine is expected to be available for operation at high altitude. However, power loss and emission deterioration have been plaguing highland Diesel engines. Therefore, this study aimed to investigate the impact of altitude on the performance and combustion characteristics of Diesel engines that is limited discussed in existing studies. The research was conducted by varying the altitude from 0-4500 m using a research Diesel engine and analyzing the combustion characteristics at different combustion phases with the help of triple Wiebe function. The results indicated a noticeable drop in power output with increasing altitude, and the deterioration of performance and emissions became significant when the altitude exceeded 3000 m. Specifically, the indicated specific CO, unburned hydrocarbon, and soot emissions increased while nitrogen NOx showed a reverse trend. Additionally, it was found that the lower cylinder pressure at high altitude extended the ignition delay and caused a higher heat release rate in the premixed combustion stage. Moreover, the high altitude condition shortened the duration of combustion and reduced the energy release fraction in the diffusion phase. Furthermore, the late combustion phase occurred earlier and lasted longer at high altitude, which consequently reduced the combustion and thermal efficiency. The most important finding is that the engine performance, especially the combustion efficiency, shows an abrupt degradation with altitudes above 3000 m. As a result, engines operating at extremely high altitudes require multi-stage turbocharging to compensate for combustion deterioration.
Investigation of no emission characteristic of ammonia-hydrogen flame in a two-stage model combustor
Authors: Wang Ping , Liu Wenfeng , Qian Weijia , Cheng Kang , Wang Yongqian , Roy Subhajit
Published: October 2023

The laminar burning velocity and NO formation process of ammonia-hydrogen combustion within a two-stage combustion chamber were investigated numerically in the present study. A chemical reactor network method involving perfectly stirred reactor, plug flow reactor, and partially stirred reactor configurations with the 24-species Xiao mechanism was implemented to simulate the premixed ammonia-hydrogen-air combustion process. The effects of inlet temperature and pressure conditions on the laminar burning velocity were investigated. Results proved that elevated pressure condition decreased primary flame thickness leading to lower laminar burning velocity while inlet temperature increased flame temperature which in turn increased the laminar burning velocity. Investigation of the effect of humidification on the laminar burning velocity showed that humidification can counteract the effect of high inlet temperature. The NO emission studies indicated a twofold impact of pressure on NO formation processes: preventing NO formation in the primary combustion zone, and promoting thermal NO formation in the lean combustion zone. The minimum amounts of NO emission were obtained at total equivalence ratios of 0.4. Humidification prevented the NO formation in the lean combustion through the competitive effect of H2O on O, whilst temperature effect was comparatively small. Humidity and pressure were optimized in the two-stage configuration achieve both low emission and high efficiency.
Research on experimental parameter selection for measuring thermal diffusivity by laser flash method at room temperature
Authors: Sun Yan , Zhong Kai , Zhang Xia , Wang Yong , Wang Guofeng
Published: October 2023

Based on the laser flash method, the selection of experimental parameters on the accuracy of measurement results for measuring thermal diffusivity is investigated in this paper. High purity graphite is employed as the experimental material. Three experimental parameters are taken into consideration, including specimen thickness, laser pulse power, and laser pulse width. Firstly, the principle of the laser flash method is introduced. Then, a numerical simulation model is established and independence tests are performed. In order to investigate the impact of different experimental parameters to the precision of the measurement results using the laser flash method, six thicknesses of the specimens, five laser pulse powers, and five laser pulse widths are selected for numerical simulation and LFA 427 measurement experiments. Finally, an orthogonal design method with three-factor and three-level is constructed to investigate the influence degree of these three factors on the measurement results. It is found that the laser pulse width has the most significant influence, while the laser pulse power has the least impact. For high purity graphite specimens, it is required to choose a thicker specimen, a lower laser pulse power, and a smaller laser pulse width to ensure better measurement accuracy.
Heat transfer characteristics of oil-water two-phase in pipeline transportation during shutdown
Authors: Xu Ying , Li Zhenjia , Zhang Qiang , Liu Xiaoyan , Ma Chuan
Published: October 2023

Gathering and transportation pipelines often appear shutdown condition due to damage, leakage, and other reasons. The reasonable maintenance time should be controlled by closely combined with the change law of the oil-water temperature in the pipeline. This paper established a multi-field coupling 3-D heat transfer mathematical model of the oil-water pipeline environment based on the two-phase shutdown pipeline as the research object. According to the changing law of the oil-water temperature field and flow field under a typical pipe diameter, the evolution behavior of the gelation layer in the pipe and the transformation process of heat transfer mode were analyzed, and the heat transfer characteristics between oil-water phase and its interface in the pipe were defined. With the liquid phase ratio of the oil phase changing the rule, reasonable maintenance time suggestions were given for gathering and transporting pipelines with different water content.
Performance assessment of PTSC-driven organic Rankine cycle systems integrated with bottoming Kalina and absorption chiller cycles: A parametric study
Authors: Dehghan Masood , Akbari Ghasem , Montazerin Nader , Maroufi Arman
Published: October 2023

It is crucial to evaluate the impact of key parameters of multi-generation systems on their performance characteristics in order to develop efficient systems. The present study conducts parametric analysis of a PTSC-driven trigeneration system with a novel energy distribution based on directfed ORC and bottom-cycled arrangement of double-effect absorption refrigeration cycle and Kalina cycle system. Three different ORC structures (simple, regenerative, and ORC integrated with intermediate heat exchanger ? IHE) are proposed. Effect of key ORC parameters namely ORC evaporator pinch point temperature and pump inlet temperature is examined on the thermodynamic performance of systems. Decrease of pinch point temperature enhances overall efficiencies and heating power in all three configurations, and increases (decreases) the net electrical power for ORC and regenerative ORC (RORC) based systems. This also enhances the cooling power of the RORC based system, though it has no impact on the cooling power of the ORC and ORC-IHE based systems. Reduction of the ORC pump inlet temperature increases overall exergy efficiency in all hybrid systems and overall energy efficiency in the ORC and ORC-IHE based systems, whereas it slightly decreases for the RORC based system. Based on a comparative study, performance of the proposed systems is found to be higher than related solar-driven multi-generation systems in the literature.
Micro-channel topology optimization based on enhanced heat transfer mechanism
Authors: Liu Wenzhu , Yun Heming , Wang Baoxue , Hu Mingzhe , Zhong Chonglong
Published: October 2023

Topology optimization modifies the material distribution in the design domain to produce micro-channel structure with improved thermal performance. In this work, five heat dissipation micro-channel structures with various design domain aspect ratios are optimally designed based on the bi-objective topology optimization method. The optimal design variable fields, temperature fields, and pressure fields are subsequently obtained for each operating condition, and the flow heat transfer effect and the enhanced heat transfer mechanism are investigated under various working conditions. On this basis, the flow heat transfer impact of micro-channels under various operating situations is optimized and studied by combining the field synergy concept and entransy dissipation theory. The findings show that when the Reynolds number rises in the laminar flow region, the complexity of the topological flow channels also rises. The average temperature, Tave,decreases, Nusselt number rises, the inlet and outlet pressure drop, ?P, gradually increases, the integrated enhanced heat transfer factor PEC gradually decreases, the field synergy number, Fc, increases, the pressure drop synergy angle, ?, gradually increases, the entransy dissipation, Evh, increases, and the flow heat transfer performance of each heat dissipation channel is also enhanced due to the complex channels and high Reynolds number in the domain. The investigation of micro-channels with various topologies revealed that the micro-channels with the same boundary conditions and a design domain aspect ratio of 25/64 had the best synergy effects of velocity-pressure gradient and velocity-temperature gradient, the best heat transfer effect, and the best flow characteristics.
ELM–2084 MMR többfeladatú légtérellenőrző, légvédelmi és tüzérségi felderítőradar
Authors: Balajti István
Published: October 2023

Az a tény, hogy Magyarország a Kárpát-medence közepén helyezkedik el, sajátos elvárásokat támaszt a katonai légtérellenőrző rádiólokátorokkal szemben. A katonai radarokkal szembeni elvárásoknak alkalmazkodniuk kell ahhoz a tényhez, hogy a környező hegyláncok lehetővé teszik határaink rejtett megközelítését. A célfelderítést, útvonalképzést és -azonosítást nehezítő intenzív állócélképződés, a változatos időjárási jelenségek és a hullámterjedési sajátosságok tovább növelik a radarokkal szembeni elvárásokat. A tanulmány röviden áttekinti és értékeli az ELM–2084 MMR típusú multimissziós mobil radar néhány fontos performancia (teljesítőképesség) jellemzőjét, kiemelt figyelmet fordít az üzemi frekvencia miatt tapasztalható előnyök és kihívások bemutatására, valamint értékelésére. Ebből a típusból a Honvédelmi és Haderőfejlesztési Program (HHP) keretében Magyarország 11 darabot vásárol Izraeltől.
gázturbinás repülőgép-hajtóművek fejlesztési irányai 3. rész
Authors: Varga Béla
Published: October 2023

A szerző tanulmányában bemutatja a propulziós rendszerek működését, a tolóerő keletkezésének összefüggéseit, ezen belül részletesen foglalkozik a gázturbinás propulziós rendszerek típusaival és szerkezeti kialakításukkal. Tárgyalja a hajtóművek hatásfokát meghatározó tényezőket, a hatásfok növelésével kapcsolatban az azokban rejlő lehetőségeket és korlátokat, valamint a hatásfok és a klímaváltozás jelentősége miatt is fontos szén-dioxid-kibocsátás összefüggéseit. Ismerteti a nemzetközi légiforgalmat érintő, a szén-dioxid-kibocsátás csökkentésére irányuló intézkedéseket, és hogy azok milyen kihívásokat jelentenek a repülőgép-hajtóművek fejlesztése szempontjából. Vizsgálja az alternatív tüzelőanyagok alkalmazásának lehetőségét, valamint azok a hajtómű termikus hatásfokára, és fajlagos hasznos munkájára kifejtett hatását. Foglalkozik a gázturbinás hajtóművek égőtereinek kialakításával, kémiai, termodinamikai és gázdinamikai kérdéseivel, valaminta keletkező égéstermék összetételével.
Katonai műszaki-technikai újdonságok a MILENG COE 2022-es ipari napján 1. rész
Authors: Bakos Tamás
Published: October 2023

A németországi Ingolstadtban, a NATO Katonai Műszaki Kiválósági Központ minden esztendőben megrendezi a Katonai Műszaki Információs Szemináriumot. Az esemény keretén belül az „Ipar Napja” rendezvényen az érdeklődők megismerkedhetnek a különböző gyártók, fejlesztők legújabb katonai műszaki és mérnöki ágazathoz kapcsolódó termékeivel. A szerző célja, hogy néhány kiválasztott műszaki innováción keresztül felkeltse az érdeklődést mind a műszaki-technikai eszközök új generációja, mind a műszaki támogatás új lehetőségei iránt.
Agricultura 4.0: uso de tecnológicas de precisión y aplicación para pequeños productores
Authors: Tovar-Quiroz Ana Delfina
Published: October 2023

El concepto de agricultura 4.0 ha emergido como una evolución de la agricultura de precisión (AP) a través de la difusión del Internet de las cosas (IoT), la analítica de datos, y el machine learning, que han sido aplicados en toda la cadena de valor del sector agropecuario. Sin embargo, los desafíos que enfrenta la agricultura hoy en día van mucho más allá de los meramente tecnológicos. El logro de la meta Hambre Cero de aquí a 2030 exigirá que se utilicen aplicaciones de Ciencia, Tecnología e Innovación (CTI), primordiales para que el sector primario se convierta en impulsor del desarrollo económico y sostenible. En el presente artículo se presenta el concepto de agricultura 4.0, los contextos particulares de su uso, así como sus beneficios y principales tecnologías aplicadas en el sector, con el fin de evidenciar las tendencias de uso a nivel global. Para ello, se tomaron en cuenta artículos en idioma inglés, publicados en los últimos 5 años, tanto de revisión como de investigación. El Internet de las cosas, la analítica de datos, la inteligencia artificial y la computación en la nube, entre otras, han sido identificadas como las tecnologías más estudiadas en sistemas agrícolas. Se abre un abanico de oportunidades para seguir revisando innovaciones que sean específicas para las regiones y sus comunidades.
Influencia de aditivos en humectabilidad del bionematicida HeberNem-S obtenido mediante secado por atomización
Authors: Paneque-Díaz Yunier Luis , González-Fernández Nemecio , Crespo-Zafra Lourdes Mariana , Zamora-Sánchez Jesús , Segura-Silva Rutdali María , Pérez-Sánchez Amaury
Published: October 2023

Brevibacterium celere C-924 es un microorganismo cuya actividad nematicida ha sido demostrada, mediante el cual se ha obtenido formulaciones en polvo (HeberNem-S) para su aplicación en casas de cultivo protegidas. El objetivo de este trabajo consistió en realizar estudios de tamizado para determinar los factores y aditivos que más influencia tienen en la humectabilidad del producto HeberNem-S durante la operación de secado por atomización. Se realizó un experimento de superficie de respuesta dónde se evaluaron los siguientes factores: concentración de sacarosa, sólidos solubles del medio de fermentación agotado, velocidad sincrónica del disco atomizador y la materia seca de la crema formulada sobre la humectabilidad del producto HeberNem-S. Los resultados del experimento demostraron que la variable que más influye en la humectabilidad del polvo es la concentración de sólidos solubles del medio de fermentación agotado que se añade en la formulación. Con base en estos resultados obtenidos se evaluó la influencia de 16 aditivos, dentro de los cuales se encuentran azúcares, gomas, detergentes y agentes tensoactivos. Se determinó que los aditivos que más influyen en la humectabilidad son la lecitina de soya y el Glanapon, logrando una reducción del tiempo de humectabilidad de 19,18 veces y 17,5 veces, respectivamente. El resultado obtenido es de vital importancia para estudios posteriores de optimización de la composición del HeberNem-S, con el fin de garantizar las mejoras continuas del proceso de producción y las propiedades físicas del polvo.
Satisfaction and Reduction of Pain Following Tele-Physiotherapy of Patients with Musculoskeletal Disorders during the COVID- 19 Pandemic Disorders
Authors: K Otadi
Published: October 2023

Introduction: This study aimed to investigate the rate of satisfaction and pain reduction in musculoskeletal patients by using tele-physiotherapy during the COVID-19 pandemic infection disease. Methods: Eighteen patients with shoulder, knee, neck, and thoracic pain received some advice through video conferencing or video calls. All participants received different exercises based on the patient’s pathology or using some accessible modalities such as cold or hot packs. Interventions were followed by online platforms such as chat/massage and video conferencing by WhatsApp or Telegram program. Pain intensity was assessed by the Numeric Rating Scale, and satisfaction was evaluated by the Telehealth Satisfaction Questionnaire. Results: Statistical analysis showed a significant reduction of pain (p< 0.001), with a high effect size = 2.9. The rate of satisfaction of patients was detected high about all questions. Conclusion: This study suggests that tele-physiotherapy can effectively reduce pain and increase satisfaction during pandemic infected disease or for patients in remote areas.
The Utility of an Occupational Therapy Intervention Using Information and Communication Technology during the COVID-19 Infection: An Intervention Report of a University Student with Autism Spectrum Disorder
Authors: Fujii Hiromi
Published: October 2023

A client living with autism spectrum disorder (ASD) went to the university and lived alone for the first time. Given the coronavirus situation, he participated in on-demand classes from his apartment from the beginning of his enrollment, and as a result over time he became unable to sustain a distinction between his academic and personal time. As a consequence, he was no longer able to complete his class assignments and, therefore, asked us for help. We implemented remote occupational therapy (OT) using information and communication technology (ICT). We emphasized teaching instrumental daily activities, daily scheduling, communication, and mental health maintenance. We implemented an OT program that encouraged the client to re-establish his daily rhythms. The program improved the client’s daytime routine and allowed them to work on assignments for on-demand classes at the university. We show that using ICT to work on the study of this case (1) does not depend on physical distance, (2) can work when needed, (3) can work as many times as needed in a day, and (4) can provide continuous support in place of face-to-face contact. These findings suggest that regular remote OT visits may help students living with ASD to continue with their university life.
formación del profesorado de matemáticas en tiempos de crisis paradigmática
Authors: Gascón Josep
Published: October 2023

El punto de vista psicopedagógico se ha ido imponiendo progresivamente en la interpretación de los hechos educativos, especialmente (pero no únicamente) en las instituciones responsables de la enseñanza preuniversitaria. No existe, sin embargo, un acuerdo sobre el tipo de matemáticas que deben enseñarse en dichas instituciones, ni sobre el tipo de argumentos que es necesario utilizar en los correspondientes procesos de enseñanza ni, mucho menos, sobre cuáles son, en definitiva, los fines de la educación matemática en esas etapas educativas. Esta ausencia de un paradigma didáctico disciplinar (matemático) compartido, constituye un claro indicador de una crisis que tiene una larga historia y en la que permanece la educación matemática no universitaria desde, al menos, el fracaso de la matemática moderna a mediados del siglo pasado. En este artículo mostraremos que la formación del profesorado vigente en nuestras instituciones docentes continúa fuertemente condicionada por el paradigma psicopedagógico y por la cultura de la «posmodernidad» en la que este paradigma se sustenta. En el caso del profesorado de matemáticas, dada la ausencia de un paradigma didáctico disciplinar compartido, la formación está regida, complementariamente, por los paradigmas didácticos subdisciplinares vigentes en cada uno de los ámbitos de la matemática escolar y no siempre compatibles entre sí.
criação do Programa de Estudos Pós-Graduados em Educação Matemática e da Revista Educação Matemática Pesquisa da PUC-SP na visão de duas personagens centrais para esses acontecimentos
Authors: Lutaif Bianchini Barbara , Loureiro de Lima Gabriel
Published: October 2023

O objetivo deste artigo é investigar o processo de criação da Revista Educação Matemática Pesquisa e do Programa de Estudos Pós-Graduados em Educação Matemática da PUC-SP, por meio de dados coletados a partir de entrevistas com personagens importantes neste processo e que tiveram um papel decisivo nos contextos em análise: as professoras Silvia Dias Alcântara Machado e Sonia Barbosa Camargo Igliori. A pesquisa realizada de natureza qualitativa insere-se, do ponto de vista metodológico no campo da História Oral Temática. Dentre os nossos questionamentos às entrevistadas, estes contemplaram os seguintes aspectos: como se deu a transição de um Programa de Matemática para um de Educação Matemática, as contribuições do Programa para o cenário da Educação Matemática brasileira, a origem da Revista Educação Matemática Pesquisa, bem como a motivação para a sua criação, os principais desafios e as principais contribuições da Revista para a Educação Matemática, em contextos nacionais e internacionais, ao longo de seus 25 anos de existência. Como resultados desta investigação, podemos afirmar que a mudança de um Programa de Matemática para um de Educação Matemática, ocorrida em 1994, foi cuidadosamente pensada pelos que nela se engajaram, contou com a colaboração de pesquisadores de renome internacional e, por meio da criação, em 1999, da Revista a ele vinculada, além de ampliar o espaço para a divulgação de pesquisas nacionais na área, oportunizou trocas internacionais - 432 instituições diferentes de 40 países fazem-se presentes nos artigos – que fortaleceram o reconhecimento tanto do Programa quanto da Revista.
percurso de estudo e pesquisa para a educação financeira
Authors: Damasceno Alexandre Vinícios Campos , Nunes José Messildo Viana , Damasceno Cleonilda Batista
Published: October 2023

A Educação Financeira é um tema cada vez mais difundindo em pesquisas de âmbito nacional e internacional, mas ainda é pouco presente em escolas brasileiras, principalmente, públicas. Nesse sentido, busca-se, com este artigo, contribuir com indicativos de como lidar com a Educação Financeira, na formação de professores, com diretrizes estendidas à escola básica. A referida pesquisa fundamenta-se na Teoria das Situações Didáticas e na Teoria Antropológica do Didático, que fornece um quadro teórico-metodológigo articulado a um dispositivo de formação denominado Percurso de Estudo e Pesquisa. Tal dispositivo possibilita a construção de respostas coletivas a questões problemáticas da área da educação, nesse caso, a Educação Financeira Escolar. A pesquisa foi desenvolvida em um curso de formação de professores para os anos iniciais de escolarização. O objetivo foi traçar diretrizes para um modelo de letramento financeiro que atenda às necessidades sociais de letramento do cidadão e às exigências das leis educacionais brasileiras. A partir do processo de estudo, produziu-se uma resposta coletiva, com diretrizes de um modelo para desenvolver o letramento financeiro na formação de professores, com potencial para adaptação para a escola básica.
Construção da relação teoria/prática por meio de estratégias para a superação da dicotomia universidade/escola
Authors: Nogueira Neslei , Nascimento Silveira Denise
Published: October 2023

Este artigo visa apresentar as práticas realizadas na disciplina de Currículo em Educação Matemática para a inserção dos discentes da Licenciatura em Matemática da Universidade Federal de Pelotas nas escolas. Para tanto, parte-se é uma síntese histórica das políticas públicas brasileiras e o seu impacto na formação inicial de professores, juntamente com apontamentos acerca do que Nóvoa (2002) designa por dilemas da profissão docente, os quais alicerçaram a ideia de que o adoecimento docente também pode ser considerado um dilema do labor destes profissionais. Desta forma, reservamos um espaço do texto para expor a proposição de que o contexto sociopolítico e econômico e os mecanismos de funcionamento das escolas podem contribuir para o adoecimento dos professores, por intermédio das políticas educacionais, que são elaboradas sob influência dos organismos multilaterais disseminadores do modelo neoliberal. Após, apresentamos um exame das práticas realizadas pelos alunos da Licenciatura em Matemática nas instituições de ensino. Na sequência, expomos nosso entendimento de que a formação inicial docente deve permitir: a construção do conhecimento pedagógico; a compreensão do licenciando de que o seu ofício exige contínuo aperfeiçoamento devido as constantes mudanças sociais, políticas, econômicas, culturais e científicas; e ao desenvolvimento de práticas que proporcionem aos futuros professores interpretar, reinterpretar e sistematizar suas experiências, para a manutenção de um processo contínuo de edificação do seu ser professor.
Educação matemática em questão
Authors: Kroetz Ketlin , Henning Paula Correa , Ozelame Diego Machado
Published: October 2023

O presente artigo objetiva problematizar a sociologia proposta pela francesa Florence Weber em consonância com a Educação Matemática, tomando como eixo articulador, principalmente, seu conceito de cena social, bem como as teorizações defendidas pelo Segundo Wittgenstein, a de jogos de linguagem. A ideia é criar possibilidades para pensar a Educação Matemática de outro modo, criando linhas de fuga e considerando os diferentes significados que ela possui na contemporaneidade. A partir disso, o presente artigo explicita alguns elementos Modernos na fabricação da Matemática, mostrando como ela foi se instituindo como uma forma de conhecimento verdadeira na sociedade ocidental em diferentes tempos e espaços. Posteriormente, apresenta a matemática como um jogo de linguagem e como cena social. Por fim, são tecidas algumas considerações a respeito de um possível rumo para a educação matemática, sugerindo que ela passe a ser visualizada de outro modo, não como uma ciência dura, mas como algo que transcende os cálculos exatos e pode ser encontrado nos modos de saber e fazer de diferentes culturas. Assim, poderiam ser levadas em consideração estratégias que divergem das impostas pela escola, possibilitando a criação de outros modos de matematizar que podem estar silenciados.
algoritmo da divisão na formação inicial do professor de matemática
Authors: Melo Carlos Ian Bezerra de , Oliveira João Luzeilton de
Published: October 2023

Entre os estudos sobre os saberes e a formação matemática do professor, vimos, nos últimos anos, surgir o interesse sobre a formação em Teoria Elementar dos Números, área da Matemática cuja preocupação são os números inteiros e suas operações. Nesse contexto, a presente investigação teve como objetivo discutir questões relativas à divisão euclidiana, mais especificamente ao algoritmo da divisão, no âmbito da formação inicial, bem como identificar e debater dificuldades evidenciadas por licenciandos em Matemática de uma universidade pública cearense em relacionar esse tópico abordado na disciplina de Teoria dos Números com o ensino da operação matemática de divisão na Educação Básica. O referencial teórico adotado aponta à necessidade de rever a forma como a disciplina de Teoria dos Números vem sendo trabalhada na licenciatura, enquanto os resultados do questionário aplicado a 18 (dezoito) licenciandos em Matemática indicaram que ideias básicas relacionadas à divisão euclidiana, e mais especificamente ao algoritmo da divisão, ainda não estão bem assentadas e articuladas nesses estudantes, o que pode sinalizar possível fragilidade nas futuras práticas docentes. Conclui-se, assim, que uma abordagem mais voltada aos significados dos cálculos e suas implicações do que à memorização e execução dos algoritmos é necessária à qualificação da formação matemática em Teoria Elementar dos Números dos futuros professores de Matemática.
Comparison of Hydrodynamic Processes Modelling Results in Shallow Water Bodies Based on 3D Model and 2D Model Averaged by Depth
Authors: Protsenko S. V. , Protsenko E. A. , Kharchenko A. V.
Published: October 2023

Introduction. Two-dimensional hydrodynamic models have proven their ability to adequately describe the processes of runoff and transportation in rivers, lakes, estuaries, deltas and seas. Practice shows that even where significant three-dimensional effects are expected, for example, with wind flows, a two-dimensional approach can work effectively. However, in some cases, the two-dimensional model does not accurately reflect the actual flow structures. For example, in shallow waters with complex bathymetry, heterogeneous terrain and dynamics can lead to a non-uniform velocity profile. The aim of the study is to develop a basis for determining in which cases a two-dimensional model averaged in depth is sufficient for modelling hydrodynamic processes in shallow waters like the Azov Sea, and in which cases it is advisable to use a three-dimensional model to obtain accurate results.

Materials and Methods. Local analytical solutions have been obtained for the propagation of the predominant singular progressive wave in a shallow, well-mixed reservoir. Advective terms and Coriolis terms are neglected, the vortex viscosity is assumed to be constant, and the lower friction term is linearized. Special attention is paid to the latter, since the characteristics of the models significantly depend on the method of determining the coefficients of lower friction. The analytical method developed in the study shows that certain combinations of higher flow velocities (u ≈˃ 1 m/s) and water depths (d ˃ 50 m) can cause significant differences between the results of the depth-averaged model and the model containing vertical information.

Results. The results obtained are verified by numerical simulation of stationary and non-stationary periodic flows in a schematized rectangular basin. The results obtained as a result of three-dimensional modelling are compared with the results of two-dimensional modelling averaged in depth. Both simulations show good compliance with analytical solutions.

Discussion and Conclusions. Analytical solutions were found by linearization of the equations, which obviously has its limitations. A distinction is made between two types of nonlinear effects — nonlinearities caused by higher-order terms in the equations of motion, i.e. terms of advective acceleration and friction, and nonlinear effects caused by geometric nonlinearities, this is due, for example, to different water depths and reservoir widths, which will be important when modelling a real sea.
Semiinvariants, Senatov Moments and Density Decomposition
Authors: Kondratenko A. E. , Sobolev V. N.
Published: October 2023

It is proposed to introduce into Probability Theory courses such a new moment characteristic of random variable as Senatov moment. Naturalness of this proposal is confirmed by three views of appearance of Senatov moments. Introducing of them will answer the question about what is analogue of Taylor series of function for density.
Pengaruh Bentuk Interaksi Sosial Terhadap Sikap Solidaritas Peserta Didik SMK Negeri 1 Bumi Ratu Nuban Lampung Tengah Tahun Pelajaran 2019/2020
Authors:   Universitas Lampung, Fitri Sofa Mutiara
Published: October 2023

Tujuan penelitian ini untuk menjelaskan seberapa besar pengaruh bentuk interaksi sosial terhadap sikap solidaritas peserta didik SMK Negeri 1 Bumi Ratu Nuban Lampung Tengah Tahun Pelajaran 2019/2020. Metode yang digunakan yaitu deskriptif dengan pendekatan kuantitatif dengan subjek penelitian peserta didik kelas X SMK Negeri 1 Bumi Ratu Nuban Lampung Tengah. Sampel dalam penelitian ini berjumlah 28 responden. Teknik Pengumpulan data menggunakan teknik utama yaitu angket dan dokumentasi, sedangkan analisis data yang digunakan adalah Chi Kuadrat. Hasil penelitian menunjukkan bahwa terdapat pengaruh yang signifikan antara bentuk interaksi sosial terhadap sikap solidaritas peserta didik SMK Negeri 1 Bumi Ratu Nuban Lampung Tengah. Dalam bentuk interaksi sosial (X) dominan pada kategori cukup berpengaruh dengan persentase 75%. Dalam sikap solidaritas peserta didik (Y) dominan pada kategori cukup baik dengan persentase 68%, serta memiliki hasil uji keeratan pengaruh sebesar 0,80 yang menunjukkan keeratan pengaruh kategori sangat kuat antara pengaruh bentuk interaksi sosial terhadap sikap solidaritas peserta didik SMK Negeri 1 Bumi Ratu Nuban Lampung Tengah Tahun Pelajaran 2019/2020.
Peranan Nyai Dalam Transfer Budaya di Daerah Perkebunan Deli Tahun 1870-1942
Authors:   Universitas Lampung, Amandah Diskalia , Susanto Henry , Ekwandari Yustina Sri
Published: October 2023

Tujuan dalam penelitian ini adalah untuk mengetahui peranan Nyai dalam transfer budaya di daerah perkebunan Deli tahun 1870-1942. Metode yang digunakan dalam penelitian ini adalah metode penelitian sejarah (historis) yaitu prosedur pemecahan masalah dengan menggunakan data masa lalu atau peninggalan-peninggalan dengan langkah-langkah berupa heuristik, kritik, interpretasi, dan historiografi. Teknik penelitian yang digunakan dalam penelitian ini adalah teknik kepustakaan dan teknik dokumentasi. Teknik analisis data yang digunakan adalah teknik analisis data kualitatif. Berdasarkan hasil penelitian yang telah dilakukan, diperoleh data bahwa terjalinnya kehidupan bersama antara laki-laki Eropa dan perempuan pribumi dalam hubungan pernyaian menyebabkan saling terpengaruhnya kebiasaan di antara keduanya yang diperoleh dari adanya interaksi yang terus-menerus secara intensif. Hal ini tidak terlepas dengan adanya peranan dari kedua belah pihak antara nyai dan tuan Eropa-nya. Semua hal tersebut dapat dilihat dalam persoalan makan yang kontras antara nyai dan tuan-nya, busana yang saling mempengaruhi, adanya pembauran bahasa, dan gaya hidup yang berbeda antara orang Eropa dan pribumi. Kesimpulan dalam penelitian ini adalah transfer budaya tidak terlepas dari adanya peranan nyai dan Tuan Eropa-nya, transfer budaya yang terjadi meliputi persoalan dan kebiasaan makan yang akhirnya memunculkan suatu istilah yaitu rijsttafel. bahasa petjoek yang tercipta dari adanya pembauran Bahasa Belanda dan Bahasa Jawa, pakaian nyai yang disesuaikan dengan perubahan pada statusnya dan sang tuan yang juga diperkenalkan dengan pakaian pribumi oleh nyai, serta adanya gaya hidup yang saling mempengaruhi diantara nyai dan tuan-nya, dimana akhirnya mereka bisa saling belajar satu sama lain.
Pengaruh Softskill Terhadap Kesiapan Menjadi Calon Guru Pada Mahasiswa Jurusan PIPS FKIP Universitas Lampung
Authors:   Universitas Lampung, Rahmanto Andi Adam , Winatha I Komang , Pujiati Pujiati , Rizal Yon
Published: October 2023

Penelitian ini bertujuan untuk mengidentifikasi pengaruh softskill terhadap kesiapan menjadi calon guru. Metode yang digunakan dalam penelitian ini adalah metode deskriptif verifikatif, objek penelitian adalah mahasiswa pendidikan IPS angkatan 2018-2021 FKIP UNILA. Teknik pengumpulan data menggunakan teknik kuisioner atau angket dan dokumentasi. Hasil penelitian ini yaitu t hitung > t tabel 3,885 > 1,967 dengan Tingkat signifikansi0,000 < 0,05. Dengan demikian dapat disimpulkan bahwa terdapat pengaruh positif dan signifikan soft skill terhadap kesiapan menjadi calon guru pada mahasiswa jurusan pendidikan ilmu pengetahuan sosial FKIP Universitas Lampung.
Dynamics of Existential Space in Educational Societies
Authors: Makhamatov Tair , Bahodirjon Ganiyev , Pulatova Dildor Akmalovna , Makhamatov Timour
Published: October 2023

This article presents a philosophic analysis of existentiality of the space of society. The authors base their research on an analysis of the works of J.-P. Sartre, A. Camus, K. Jaspers, C. Jung, L, Vygotsky, E. Fromm, J. Salinger, S. Beckett, and other recent representatives of existential philosophy, psychology, and existential fiction. The main goal of the present study is to define the existential space and discuss the main determinants of existentialization of social ontology. The results of this study are as follows: definition of the existential social space as a space of society where negative socio-psychological tensions, the dominance of “the war of all against all”, and indifference of the society towards its members engender and intensify the existential tension in its representatives; discussion of a special feature of the social time existence, which is formed under the influence of space existence and manifested as slowing down, stopping, or acceleration of time in the perception of an existential subject; description of the main levels of the existential space and time of society; suggestion of possible methods of dialectical “relief” mitigating the existence of the society and its actors.
An Evidence-based Practice Project: Using Cryotherapy for Headaches
Authors: Cosher Raeanne
Published: October 2023

This evidence-based practice project addresses the use of cryotherapy as an intervention in reducing the symptom of pain in patients with headaches. A literature review was conducted using PubMed, ProQuest Nursing and Allied Health, Cochrane Reviews, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). The articles identified were evaluated to determine evidence level and quality. Seven articles were determined to be eligible to answer the following PICO question: In patients with headaches (P), how does cryotherapy (I) compare to standard care (C) with pain (O)? A total of seven articles were used in the review. Level I, II, IV, and V articles were identified ranging from high quality (A) to good quality (B). Each article focused on using cryotherapy in treating pain during headaches, either in conjunction with other analgesia or on its own. Each article identified an overall positive effect on pain. There is compelling evidence to treat a headache with cryotherapy. The recommendation includes using an ice or cool gel pack in conjunction with the standard treatment of headache to relieve headache pain.
Surgical Treatment for Branched Endograft Thrombosis of the Abdominal Aorta
Authors: Gilemkhanov A. R. , Plechev V. V. , Bakirov A. A. , Safin R. F. , Abdrakhmanov R. E. , Blagodarov S. I. , Ibragimov T. R. , Gilemkhanova I. M.
Published: October 2023

Introduction. Endovascular intervention was firstly introduced for repairing aortic aneurysms in the early 1990s. The greatest advantage of endovascular aneurysm repair (EVAR) is its minimally-invasive character, thus implying shorter post-operative period. The operative mortality rate comprises 3.3 % (95 % CI 2.9–3.6); however, according to recent studies, the rate has declined to 1.4 % due to a rapid improvement in outcomes. According to the DREAM-trial, the incidence of a branched endograft thrombosis accounts for 6.4% within the first 30 days. The EVAR trial reports an incidence of 2.6% after the first year of follow-up. Stent bending and small distal aortic diameters (less than 20 mm) are believed to be the most common causes of endograft thrombosis.Aim. To identify the causes of complications following the abdominal aortic stent-graft repair and to determine the optimal treatment strategy.Materials and methods. The paper presents a case of 71-year-old patient with late complication after endovascular abdominal aortic repair of an infrarenal aortic aneurysm. The patient was admitted to the hospital on January 05, 2020 as an emergency due to the pain in the left lower limb. On December 03, 2019 the patient underwent endovascular abdominal aortic repair. Angiography of January 06, 2020 revealed thrombosis of the left branch of the stent graft. Thrombectomy of the brunched left stent graft, left iliac artery and balloon dilatation of the brunched left stent-graft were performed.Results and discussion. Endovascular abdominal aortic repair stands as the first choice for patients with appropriate aortic anatomy and those with significant comorbidity. Despite the significant progress in endovascular abdominal aortic repairing, the EVAR procedure is followed by a nearly fivefold increase in the 30-day reintervention rate as compared to open surgery which comprises 9.8 % according to the EVAR-I, and 18 %, according to the EVAR-II trials.Conclusion. Our multidisciplinary team consisted of vascular and endovascular surgeons managed to perform hybrid surgery, thus eliminating the EVAR-associated complication together with its cause.
The Impact of Using Memsource Termbase System on Developing Terminological Competence for Saudi Freelance Technical Translators
Authors: Safar Alqahtani Asrar
Published: October 2023

The current qualitative study aimed at assessing the impact of using the Memsource termbase system on developing terminological competence for 10 Saudi freelance technical translators registered in the Saudi freelance platform Bahr and the two social media websites Twitter and Telegram. As Arabic specialized translations often contain inconsistent and inaccurate use of terminology, this study focused on developing terminological competence using the terminology tool. To assess the impact of the terminology tool on the participants’ terminological competence, the participants in this study were divided into two groups: one group was assisted with the terminology tool—referred to as tool-assisted—and the other was not—referred to as non-tool-assisted—. Both groups completed a translation task and an open-ended questionnaire. As developing terminological competence assists in dealing with terms effectively, the terminology tool used by the participants in this study allowed the participants to create their termbases before translating the assigned technical text. These termbases were then incorporated into the tool, and when the participants started translating the text, the tool suggested the previously translated terms. To analyze the obtained data, descriptive content analysis and thematic analysis were used: the former was used to analyze the translations, and the latter was used to analyze the questionnaires’ responses. The study concluded that the terminology tool assisted in developing the tool-assisted participants’ terminological competence regarding identifying terms, creating term bases, and managing terminology during the translation process.
A Study of Player Behavior And Social Influences to Purchase Intention Mobile Legends: Bang Bang In-Game Item
Authors: Subarkah Windu Praditiyo , Santoso Adi , Widhianingrum Wahna
Published: October 2023

Purpose: This quantitative study aims to analyze the interest in buying items and skins in the online game Mobile Legends in Indonesia, especially in East Java Province by looking at the psychological and social factors of game players. Player behavior is a psychological factor and social factors are social influence variables.

Design/methodology/approach: The number of samples in this study was 310, the sampling method used purposive sampling. Respondents are active Mobile Legends game players who have participated in answering our research questionnaire. The data collection method uses online questionnaire distribution using Google Forms. Measurement of data using answers with a Likert scale of 1 to 10 with 1 point strongly disagree and 10 points strongly agree. Data were analyzed using the PLS-SEM method using Smart PLS 3.0 software.

Findings: Player behavior includes achievement, challenge, escapism, and social interaction. Social influences consist of network externality and community involvement. The results of our research show that player behavior consists of achievement, challenge, escapism, and social influences such as network externality, and community involvement have a significant positive effect on Purchase Intention.

Originality/value: This study explores the purchase intention of virtual item in the mobile legends game using the uses and gratifications theory (U&G). The application of U&G theory is seen from the behavior of the players. Social influences is also applied to see the influence from outside the players.
THE NDVI INDEX CHANGE OF THE CARPATHIAN REGION OF UKRAINE DURING 2000-2022
Authors: Glukh O.S. , Symkanych O.I. , Kachaiev V.M. , Hliudzyk E.I.
Published: October 2023

Systematic monitoring of the Carpathian region is necessary to preserve its unique natural resource potential. The NDVI index, or - Normalized Differential Vegetation Index, - is a convenient and informative indicator of the state of the vegetation cover, and is calculated on the basis of satellite data on the absorption and reflection of red and near-infrared radiation by the studied surface.

To study the dynamics of vegetation index values and the state of the vegetation cover of the Carpathian region, images from the space projects Landsat 7 and 8 for the years 2000, 2013, 2020, 2021 and 2022 were downloaded and processed. The best indicator for analyzing changes in the state of vegetation cover in space and time is the integral index NDVImean. For 12 out of 15 processed images, the highest value of the integral index NDVImean=0.40-0.42 was found for polygon 1, which covers part of the Transcarpathian region. The lowest values of 0.13-0.16 were found for polygon 3, which covers parts of the Lviv, Ivano-Frankivsk, and Ternopil regions. The values of the areas covered with healthy or dense vegetation, for which NDVI˃0.33, were calculated. The maximum value of this indicator was 81.54% for polygon 1 in 2021, and the minimum was - 52.89% - for the polygon 3 in 2013.

Keywords: Carpathian region; vegetation cover; vegetation index; multispectral analysis; raster; extent.
Investigation on the Physicochemical Properties of Blended Algae-Diesel Fuel with Nanoparticles Additive Using Mixture Design Method
Authors: Sharudin Hazim , Ismail Noor Iswadi , Che Mat Sharzali , Khairul Salleh Nurul Nabilah , Abdol Rahim Abdul Hadi
Published: October 2023

Biodiesel from algae sources is one of the most promising alternative fuels to substitute fossil fuels in the future as it has relatively high oil content, besides rapid biomass production. However, in terms of exhaust emissions, the nitrogen (NOx) emission stemming from algae-diesel blends is higher due to the presence of oxygen content. As a solution, one of the approaches is by using the addition of fuel additives, such as nanoparticles as it plays a major role in increasing biodiesel performance and improving the properties of the biodiesel blends. Therefore, this study directly focuses on improving algae-diesel blends by adding cerium oxide as the fuel additive. The main phases involved in this research are the extraction of algae oil, blending process of algae-diesel with cerium oxide and data collection of dynamic viscosity with calorific value. Then, the data collected were used as an input for Design of Expert (DOE) software to obtain the optimum blends for algae-diesel blends with cerium oxide addition. Analysis of variance (ANOVA) was applied to evaluate the properties of the blends and provides equations for the model, wherein the equations involved in this research were dynamic viscosity and calorific value. The equations generated through the software were used to obtain the theoretical value of dynamic viscosity and calorific value. Finally, the theoretical value was further validated by comparing it with the experimental data for each of the blends. The results of experimental and theoretical (predicted) for each blend model showed the percentage errors between the experimental and the calculated values was between 0.19% and 9.51%. Hence, numerically derived equations are considered valid and reliable. In conclusion, the results showed that the optimum blend obtained by the software was significant and complied with the biodiesel standard of EN14213.