bluuebunny/crossref_metadata_2025_split huggingface dataset:
ВЯЗКОСТЬ И ВНУТРЕННЕЕ ТРЕНИЕ В ЖИДКОСТЯХ
Authors: МИЗЕРОВСКИЙ ЛЕВ НИКОЛАЕВИЧ , СМИРНОВ ПАВЕЛ РОСТИСЛАВОВИЧ 
Published: November 2021

Обосновывается точка зрения, согласно которой термин «вязкость жидкости» относится к физическому параметру, характеризующему энергетические затраты на преодоление сил внутреннего (молекулярного) трения при поступательном и вращательном движении в жидкостях твердых тел и пространственном перемещении (течении) самих жидкостей. Показано, что в рамках такого подхода вязкость имеет размерность Дж⋅сек/м3, а ее численное значение зависит от трех параметров: теплоты испарения жидкости при температуре плавления, средней длительности межмолекулярных контактов при данной температуре и характерного для каждой жидкости критического значения этого параметра.
ЭКСПЕРТИЗА ВЫСКАЗЫВАНИЯ Д.И. МЕНДЕЛЕЕВА О БРИТАНСКОМ ЛИМИТЕ ДЛЯ БЕЗОПАСНОГО КЕРОСИНА
Authors: СМИРНОВ ВИТАЛИЙ ВЛАДИМИРОВИЧ , АЛЕКСЕЕВ СЕРГЕЙ ГЕННАДЬЕВИЧ , БАРБИН НИКОЛАЙ МИХАЙЛОВИЧ 
Published: November 2021

В работе проведена экспертиза высказывания Д.И. Менделеева о «надломе привычек» Британского парламента при установлении нового лимита для безопасного керосина в 1879 году. Формально оснований для этого высказывания Д.И. Менделеева нет, поскольку официальное уменьшение этого лимита было связано с переходом от стандартного английского прибора открытого типа к новому закрытому тестеру Абеля. Поскольку в научно-практической деятельности Д.И. Менделеева отсутствует, такая черта, как небрежность, поэтому возникает закономерный вопрос: кто прав? Для решения этой задачи реконструирована картина основных событий, связанных с появлением безопасных лимитов по температуре вспышке (воспламенения) для осветительных масел (керосинов) На основании анализа полученной картины событий выявлено, что при переходе на новый лимит 73 °F присутствовала заинтересованность со стороны Нефтяной комиссии, которая была ответственная за допуск импортных керосинов на внутренний рынок Британских островов. При сравнительном изучении методик определения температуры вспышки в стандартном английском приборе, аппарате Джона Тальябу и закрытом тестере Абеля установлено, что необходимости в прямой фальсификации результатов контрольных испытаний керосина не было. Несовершенство методики Нефтяного закона 1868 года, а также организация проведения этих испытаний позволяла без особых усилий достигнуть желаемого результата для Нефтяной комиссии при Британском парламенте. Таким образом утверждение Д.И. Менделеева о «надломе привычек» Британского парламента следует признать справедливым не в полной мере.
ТЕРМИЧЕСКОЕ РАЗЛОЖЕНИЕ КАТИОННЫХ, АНИОННЫХ И ДВОЙНЫХ КОМПЛЕКСНЫХ СОЕДИНЕНИЙ 3d-МЕТАЛЛОВ
Authors: ДОМОНОВ ДЕНИС ПЕТРОВИЧ , ПЕЧЕНЮК СОФИЯ ИВАНОВНА , ГОСТЕВА АЛЕВТИАНА НИКОЛАЕВНА 
Published: November 2021

Обзор посвящен рассмотрению термического поведения катионных, анионных и двойных комплексных соединений 3d металлов (Fe, Co, Ni, Cu, Mn , Cr) в сравнении с комплексами благородных металлов, с координированными аммиаком, органическими аминами, мочевиной, цианидом, тиоцианатом, оксалатом и нитритом. Показано, что в процессе термолиза, проводимого в неравновесных условиях, двойные комплексы выдерживают нагревание до 200–250 °С вне зависимости от их термодинамической устойчивости.
ЖИДКОСТНОЕ РАВНОВЕСИЕ
Authors: МИЗЕРОВСКИЙ ЛЕВ НИКОЛАЕВИЧ 
Published: November 2021

Показано, что химические потенциалы компонентов бинарных жидких смесей, образующих ветви бинодали жидкостного равновесия действительно численно равны, но имеют противоположные (+ и –) знаки и размерность Дж/моль, а условием этого равновесия является численное равенство температуре, при которой равновесие реализуется, отношений изменений энтальпии к изменениям энтропии сосуществующих пар бинарных смесей при их превращении из гетерогенных в гомогенные.
ВЛИЯНИЕ СОСТАВА ФТОРКАУЧУКОВ НА СВОЙСТВА ИХ ВУЛКАНИЗАТОВ
Authors: СИМОНОВ АЛЕКСАНДР СЕРГЕЕВИЧ , ТРИФОНОВА ИРИНА ПАВЛОВНА , РОДИЧЕВА ЮЛИЯ АЛЕКСАНДРОВНА , АЛЕКСАНДРИЙСКИЙ ВИКТОР ВЕНИАМИНОВИЧ , БУРМИСТРОВ ВЛАДИМИР АЛЕКСАНДРОВИЧ , КОЙФМАН ОСКАР ИОСИФОВИЧ 
Published: November 2021

Квантово-химическим методом проведена оценка молекулярной поляризуемости и дипольных моментов фрагментов сополимерных фторкаучуков. Показано, что полярность фторкаучуков обеспечивается присутствием винилиденфторидных звеньев. Методом динамического механического анализа получены частотные и температурные зависимости модуля упругости Е’ и тангенса угла механических потерь tgδ фторкаучуков и вулканизатов на их основе. Установлены особенности влияния состава каучуков и вулканизации на механические и теплофизические характеристики эластомеров. Получены значения прочности при растяжении и удлинения при разрыве вулканизатов исследованных фторкаучуков, а также вязкости по Муни и остаточной деформации при сжатии. Установлено, что решающее влияние на эти параметры оказывают полярность каучука и параметры вулканизационной сетки. Изучена кинетика набухания каучуков и резин на их основе в 1,2-дихлорэтане при 50оС. Проведена оценка степени ограничения сорбции растворителя при возникновении вулканизационной сетки, а также ее параметры. Установлено, что эластомеры по снижению их равновесной степени и скорости набухания в дихлорэтане располагаются в ряду: СКФ-26 >Элафтор 3061Р> Элафтор 7075> Элафтор 1000Р , симбатно уменьшению их полярности.
ПОТЕНЦИОМЕТРИЧЕСКОЕ ИССЛЕДОВАНИЕ УСТОЙЧИВОСТИ КОМПЛЕКСОВ ДИГЛИЦИНА С ИОНАМИ МЕДИ(II), НИКЕЛЯ(II) И КОБАЛЬТА(II) В ВОДНОМ РАСТВОРЕ
Authors: ГОРБОЛЕТОВА ГАЛИНА ГЕННАДЬЕВНА , БЫЧКОВА СВЕТЛАНА АЛЕКСАНДРОВНА , КРУТОВА ОЛЬГА НИКОЛАЕВНА , ФРОЛОВА КСЕНИЯ ОЛЕГОВНА 
Published: November 2021

Методом потенциометрического титрования были изучены комплексообразующие свойства глицил-глицина с ионами меди(II), кобальта(II) и никеля(II) на фоне нитрата калия (I = 0,2) при температуре 298,15 К. Исследования проводили с помощью прибора «Мультитест» ИПЛ-311. Температуру потенциометрической ячейки, титранта и электрода поддерживали с точностью ±0,1 °С с помощью термостата LOIP. Были определены состав и устойчивость комплексов диглицина c ионами Cu(II), Co(II) и Ni(II) в широком интервале концентрационных соотношений: 1:1, 1:2, 1:3, 1:5 (СM = 0,01 моль/л). Экспериментальные данные обрабатывали с помощью универсальной программы «PHMETR», предназначенной для расчета констант равновесия с произвольным числом реакций по измеренной равновесной концентрации одной из частиц. Установлено существование частиц состава: ML+, MH-1L, MH-2L-, MHL2+, ML2, MH-1L2-, MH-2L22- для системы медь(II) - диглицин, частиц состава: ML+, MH-1L, ML2, MH-2L22-, ML3-, MH-3L34- для систем никель(II) - диглицин и кобальт(II) - диглицин. Для подтверждения состава комплексов, образующихся в системе М2+ - диглицин, использовали спектрофотометрический метод. Были сняты спектры поглощения растворов М(NO3)2 в присутствии диглицина при соотношении М : L = 1 : 5 и различных значениях рН.
English Language Teachers’ Beliefs and Practices Concerning Continuous Assessment in Omani Cycle 1 Schools
Authors: Said Al-Harrasi Khalsa Khalaf , Gabarre Serge , Mirza Chaharazed 
Published: November 2021

Aims: In this study, the authors investigated English language teachers’ beliefs on continuous assessment, the relationship between their beliefs and continuous assessment practices, and factors influencing teachers’ continuous assessment practices in Cycle 1 schools in the South Batinah Governorate in the Sultanate of Oman.
Study Design: The authors used a mixed-methods approach employing an explanatory sequential design. In the first phase, a questionnaire investigating teachers’ beliefs and assessment practices was distributed to 154 teachers. In the second phase, interviews and artefact observation were conducted with three teachers. Principal components analysis was used to analyze questionnaire data, whereas interviews were analyzed using thematic analysis.
Results: The results indicate that teachers demonstrate positive beliefs towards the implementation of continuous assessment. They highlighted some aspects of the benefits of continuous assessment such as providing feedback to learners and parents and encouraging teachers to use a variety of methods, reflect on their assessment practices and adapt their techniques. However, discrepancies were found between teachers’ reported beliefs and their continuous assessment practices. These discrepancies resulted from large class size, lack of time, syllabus and timetable load, mixed learner abilities, lack of clarity of the assessment handbook, parents’ attitudes, and inadequate assessment training.
Conclusion: The study is significant because it helps clarify the relationship between teachers’ beliefs and their assessment practices. In addition, the study provides information for policymakers, assessment designers, and training program designers on the current implementation of continuous assessment in Cycle 1. The study significantly contributes to the existing literature since to the best of the authors’ knowledge it is the first study conducted in Oman investigating teachers’ beliefs on the practices of continuous assessment in Cycle 1 schools.
Knowledge of Rural Secondary School Students on First Aid Following Educational Intervention
Authors: Uddin A. F. M. Salah , Zahan Syeda Israt , Zinnah Fatema Binte , Rahman Md. Motiur , Sultana Hafiza , Mosiul Alom Foisal Mohammad , Ahshan Md. Amimul 
Published: November 2021

Introduction: School life is an important part of children’s lives, which has a direct impact on their physical and mental health. Knowledge of health promotion and prevention activities encourages initiating first aid activities in society.
Objective: To assess the level of knowledge of rural secondary school students following educational intervention on first aid.
Methodology: A quasi-experimental study was carried out among 320 secondary school students. Educational intervention on first aid was applied to compare the level of knowledge before and after the intervention. Data were collected by a self-administered structured questionnaire through randomly selected students.
Results: Findings showed that most of the respondents (84.2%) were between 12-15 years old and their mean age was 14.3 years. It was also found that the majority 159 (58.5%) of the respondents were male and the rest of them 113 (41.5%) were female. Regarding family type distribution, the majority 192 (70.6%) of the respondents lived in a nuclear family and 80 (29.4%) belong to joint family. In addition, 43 (15.8%) students' fathers were farmers, 74 (27.2%) were businessmen and 43 (15.8%) were day laborers. Regarding textbook knowledge on first aid 270 (99.3%) respondents knew the meaning of first aid, 232 (85.3%) students gave their opinion about cleaning the skin with Dettol or savlon in case of injury and 228 (83.8%) students answered that bleeding should be reduced by applying pressure with a clean cloth. The study found that 22 (8.1%) respondents had a good knowledge of first aid interventions before the intervention while after the intervention, a good level of knowledge was found amongst 189 (69.5%) students. The study revealed that the use of ice during injury management was not significantly (c2 =0.529, p˃ 0.05) associated with the level of first aid knowledge statistically before the intervention while after first aid intervention, there was a significant association (c2 =7.235, p˂ 0.05).
Conclusion: Educational intervention on first aid improves the level of knowledge among secondary school students. Necessary measures should be taken to encourage health promotion and prevention activities during practical life.
Exploration of Omani Cycle 1 English Teachers’ Continuous Assessment Practices and Perceptions
Authors: Ghafri Nawal Al , Gabarre Cécile , Mirza Chahrazed 
Published: November 2021

Aim: This article presents the findings from a qualitative exploratory study conducted in Oman that sought to uncover the factors leading to the identified gap between the SAH CA assessment standards and current grades 1 and 2 teachers’ practices. The research investigated Omani grade 1 and 2 English teachers' practices and perceptions regarding the implementation of continuous assessment (CA) in teaching English as a foreign language.
Study Design: A constructivist grounded theory method investigation was conducted to examine the influence of teachers’ beliefs, previous experience and contextual factors on their CA classroom practices and to discover the relationship between teachers’ stated beliefs and their actual classroom practices leading to the gap between CA standards and their practices. Three instruments were used namely classroom observations, semi-structured interviews, and artifact analysis. Six teachers from Al Dhahirah were observed and three teachers out of the six were interviewed to seek an in-depth understanding of their beliefs. A three-stage coding process and the constant comparative method were used to analyze the data and triangulate beliefs and practices.
Results: Even though results demonstrated that teachers believed in the importance of CA and expressed positive beliefs towards CA, the analysis showed a gap between the teachers’ actual practices and their stated beliefs regarding CA implementation in their practices. Moreover, findings highlighted the influence of the teachers’ previous experience and impeding contextual factors on the teachers’ CA practices.
Recommendations: Therefore, it is recommended to involve teachers in consistent in-service training as well as CA discussion sessions to support CA practices directing the teachers’ attention to the bright side of the assessment, its advantages, and its importance in the teaching learning process. Providing teachers with assistant teachers may help to alleviate overcrowded classes and heavy timetables. In addition, reducing the number of textbooks in the syllabus would provide more time for assessment in daily teaching.
Examining the Factors Affecting the Success of the Establishment of Village-Owned Enterprises
Authors: Solimun . , Yanti Indah , Kusumaningrumi Adi , Widodo Agus Wahyu 
Published: November 2021

Aims: This study aims to analyze the influence of Village Government Policies, Village Financial Institutions, Resources, and Community Factors on the Success of the Establishment of Village-Owned Enterprises (VOE) with Village Government Support as moderating variables.
Study Design: SEM WarpPLS.
Place: Sumberputih Village, East Java, Indonesia.
Methodology: This research is quantitative research. The research instrument used a questionnaire. The research was conducted in Sumberputih Village, East Java, Indonesia. The sampling process used a simple random sampling technique and obtained 100 respondents. Data analysis using SEM WarpPLS.
Results: The results showed that the Village Government Policy, Village Financial Institutions, Resources, and Community Factors had a significant effect on the success of the establishment of VOE (Y). Meanwhile, Village Government Support cannot moderate the influence of the four variables on the success of VOE establishment.
Blood Profile and Selected Organ Histopathology of Balami Sheep Fed Shea Cake (Vitellaria paradoxa) Meal
Authors: Okunlola D. O. , Shittu M. D. , Olatunji O. O. , Amuda A. J. , Olateju B. O. , Fasola A. A. , Alao A. J. 
Published: November 2021

The blood profile and histology of selected tissues (kidney, lungs, intestine, and epididymis) of Balami Sheep fed Shea Cake meal supplement was investigated. A total of thirty-two (32) sheep of the average weight range of 11.75-14.75kg comprising an equal number (16) of males and females were randomly allotted to four dietary treatments in a completely randomized experimental design with eight sheep per treatment for twelve weeks duration. Treatment 1 (T1) was a control diet and had zero inclusion level of Shea cake meal (SCM), while treatments 2,3, and 4 had 10%,15%, and 20% inclusion of SCM, respectively. At the twelfth week of the experiment, two blood samples of 5ml each were taken from each animal from the jugular vein. The first set was preserved in Ethylene Diamine Tetra Acetic Acid (EDTA) bottle for haematological parameters, while the second samples were preserved without EDTA for serum examination. Representative samples of tissues were randomly selected and slaughtered for gross microscopic examination. There was a significant difference (P<0.05) at various levels of inclusion for parameters investigated. The white blood cell (WBC), Red blood cell (RBC), and Packed cell volume (PCV) recorded the highest values at T3 (15% inclusion level) (13.42 x109/L), 2.92x1012/L, 3.75%, respectively). The serum parameters were significantly(p <0.05)different among the treatments. Total protein ranges from 54.78(mg/dl) (T1) - 60.51(mg/dl) (T2), Cholesterol70.15(mg/dl) (T1) - 78.00(mg/dl) (T4). Iron ranges from 58.15(ug/dl) (T1) - 62.88(ug/dl) (T3).The histopathology of tissues (kidney, lungs, intestine, and epididymis) showed no alteration across the treatments (P= .05) in the gross microscopic examinations. No lesion was observed in the lungs, kidney, epididymis, and intestine. The results showed that shea cake meal posed no health risk to Balami sheep and as such recommended as a good supplement in the diets of the sheep.
Cerebroplacental Ratio on Doppler as a Predictor of Fetuses at Risk of Perinatal Complications
Authors: Elraey Salwa Abdelmaged , Elnamoury Mohammed Mohsen , Othman Ahmed Mohammed , Awara Ahmed Mahmoud 
Published: November 2021

Background: Doppler velocimetry is the best method of surveillance for fetal hypoxemia during pregnancy. Cerebroplacental ratio (CPR), has been suggested as a useful clinical simplification. It is believed that the CPR better predicts adverse perinatal outcomes than its individual components and better than conventional anthropometric models. Therefore, the aim of this study is to evaluate the significance of the cerebroplacental 10th centile threshold measured weekly from 36 weeks of gestation till delivery as a screening test for prediction of need for Cesarean section for intrapartum fetal compromise and the adverse neonatal outcome in women with normally grown fetuses and uncomplicated pregnancy.
Methods: This study was carried out on 40 pregnant women uncomplicated, singleton pregnancy with appropriately grown fetuses on clinical assessment. The last Doppler indices including cerebroplacental ratio measurement obtained before labor was reported. CPR values below 1.1 were reported as abnormal. Various studies have variably defined the threshold of abnormal CPR ratio as <1.08.
Results: There was significant decrease in the Mean of CPR among patients who had anemia compared to those without anemia. In addition, there was no significant association seen between low CPR and having previous history of abortion or IUGR as well as being a smoker. There was no significant difference between cases who had normal and abnormal CPR regarding gestational age at delivery. There was no difference between cases who had normal and abnormal cerebroplacental ratio regarding mode of delivery. there was significant decrease in the prevalence of low birth weight among group who had CPR≥1.08. CPR <1.08 was significantly associated with neonatal complication like NICU admission, and neonatal death. There was no statistically significant relationship between cerebroplacental ratio and neonatal complication like IUFD, and neonatal sepsis. There was no statistically significant association between the mean cerebroplacental ratio and IUFD. There was statistically significant association between the mean cerebroplacental ratio and NICU. There was no statistically significant association between the mean cerebroplacental ratio and neonatal sepsis. The mean cerebroplacental ratio of 0.93± 0.22 has a significant association with neonatal death.
Conclusion: A low cerebroplacental ratio reflects redistribution of the cardiac output to the cerebral circulation and has been shown to improve accuracy in predicting adverse outcome compared with Middle cerebral artery (MCA) or Umbilical artery (UA) Doppler alone. Therefore, integrating CPR in clinical management may help to better identify fetuses at risk for adverse perinatal events, since abnormal CPR has been associated with an increased risk of perinatal complications.
Brazilian Version of the Dental Environment Stress Questionnaire
Authors: D. Presoto Cristina , Silva Ingrid Mertens , Wajngarten Danielle , Pimenta Filipa , A. D. B. Campos Juliana , M. Pazos Júlia , A. S. Domingos Patrícia , P. N. S. Garcia Patrícia 
Published: November 2021

Aims: To perform cross-cultural adaptation of the Dental Environment Stress Questionnaire (DES) for use in Portuguese-speaking populations, evaluate its psychometric properties, and determine the effects of gender and educational level in the perception of stress sources in dental students.
Methodology: An observational cross-sectional study design was implemented to examine face and content validity. 466 Brazilian students participated in the study in 2015 (UNESP students response rate=79.2%; UNIARA students response rate=82.4%). Construct validity was assessed via the determination of factorial, convergent, and discriminant validity. Reliability was estimated using Cronbach's α, and composite reliability. A model was designed using structural equation modeling, to verify the effects of gender and educational level on the perception of stress sources.
Results: The complete model purposed was not a good fit to the sample (λs=0.358–0.955, ꭙ2/df=3.36, CFI=0.881, TLI=0.870, RMSEA=0.071, r=0.426–0.664, AVE=0.366–0.856). After the removal of item 12 and insertion of a correlation between the errors for items 1 and 2 (LM=399.154) and Items 14 and 16 (LM=146.216) the model fitted the sample (λs=0.411–0.955, ꭙ2/df=2.54, CFI=0.926, TLI=0.919, RMSEA=0.058, AVE=0.363–0.850). Adequate content validity ratios were observed for 23 items. Gender affected all DES factors, and educational level influenced four factors.
Conclusion: Cross-cultural adaptation process provided an instrument that was easy to understand, with adequate idiomatic and cultural equivalence. The Portuguese version of the DES showed good psychometric properties and reliability in the study sample. Gender and educational level exerted significant effects on seven and four factors, respectively.
Long Term Behavior of Ultra High-Performance Concrete
Authors: A. Etman Zeinab , M. Soliman Noha , M. Abou Raia Mahmoud 
Published: November 2021

Ultra-High-Performance Concrete (UHPC) is one of the important types of concrete technology breakthroughs in the 21st century. It achieved high results of mechanical properties, durability (resistance fire) and bonding strength. The aim of paper is to evaluate the long-time behavior of UHPC. The main variables were finesse modulus of sand, crushed quartz powder, fly ash and metakaolin and methods of curing (water& hot).The sand with different fineness modulus(3.2, 2.36 and 1.9) were used, Crushed quartz powder with ratio (10%, 20% and 30%) as a replacement of sand was used. Fly ash and metakaolin, with of (10%, 20%, 30 and 40%) and (5%, 10% and 15%) as a replacement of cement; respectively. The effect of these variables on the mechanical properties (compressive, tensile, flexural strength) at different ages. Also, the drying shrinkage strain was evaluated. The results showed that using and with fineness modulus (1.9), 20% ratio of crushed quartz powder to fine sand (CQ/S), 20% of fly ash to cement (FA/C) and 5% of metakaolin to cement (MK/C) give the best proportions of UHPC. The compressive strength for this mix was 900 kg/ cm2 .