bluuebunny/crossref_metadata_2025 huggingface dataset:
Teaching and Assessment through Online Platforms during the COVID-19 Pandemic: Benefits and Challenges
Authors: Aina Adebunmi Yetunde , Ogegbo Ayodele Abosede
Published: December 2021

The outbreak of the COVID-19 pandemic has compelled education systems across the globe to fully embrace online learning as an alternative to face-to-face classes. This has resulted in a paradigm shift, in which online teaching and assessment practices continue to gain prominence at the tertiary level. Hence, this study explores lecturers' teaching and assessment strategies for teaching university students through online platforms during the COVID-19 pandemic. This study has used a framework of SWOT (strength, weakness, opportunities, and threats) analysis as its theoretical base. Data was collected through semi-structured interviews with five lecturers from three universities in Gauteng Province, South Africa. The collected data was analysed using content analysis. This study found that lecturers were able to manage the teaching and assessment processes during the COVID-19 school restrictions, using a combination of platforms such as Blackboard-collaborate, WhatsApp, Kahoot, and Google Classroom. The findings also revealed that a wide variety of teaching and assessment methodologies, including small group work, collaborative learning, case methods, discussion posts, multiple choice quizzes, chats, game activities, open-ended questions, and essays were utilized on these platforms. Although the methodologies used for teaching and assessing on these platforms require additional preparation time, they also help increase interaction between students and enable immediate grading of scripts and student feedback. Further findings revealed that online assessment is highly susceptible to test/examination malpractices. This study provided recommendations helpful to policymakers, lecturers, and students regarding online teaching and assessment strategies.
Evaluación de la microfiltración en restauraciones con resina Clase I
Authors: Cáceres Díaz Laura María , Núñez Heriberto , Perdomo Mirtha
Published: December 2021

Objetivo: Comparar la profundidad de microfiltración en restauraciones con resina en cavidades Clase I, variando el método de restauración y el sistema adhesivo. Material y Métodos: se realizó un estudio experimental ex vivo, en el que se incluyeron 128 molares sin alteraciones morfológicas en la estructura coronaria, en los cuales se tallaron cavidades en la cara oclusal en forma estandarizada (4x4x3mm) y posteriormente distribuidos en forma aleatoria en dos grupos según el sistema adhesivo aplicado (Grupo I, grabado ácido previo al adhesivo; Grupo II, adhesivo autograbado), subdividiendose a su vez cada grupo en dos subgrupos según el método de restauración, A: resina compuesta; B: base de resina fluida, restauración con resina compuesta y sellador superficial. Todos los cuerpos de prueba fueron sellados en el ápice y en toda la superficie externa con dos capas de esmalte de uñas hasta 1 mm de la interfase diente-restauración, termociclados entre 5 °C y 55 °C, sumergidos en azul de metileno al 2% durante 24 horas y cortados transversalmente en sentido vestíbulo palatino/lingual para realizar la medición en milímetros. Resultados: Los datos fueron analizados estadísticamente con IBM SPSS stadicts versión 2.0, aplicando ANOVA de doble clasificación; se observó diferencia estadísticamente significativa (p<0,05) entre los subgrupos según el método de restauración. Conclusiones: la utilización de base y sellador superficial en combinación con la restauración de resina compuesta disminuyeron la microfiltración aplicando tanto el sistema adhesivo con grabado ácido previo como el sistema adhesivo autograbado, mientras que la mayor microfiltración se obtuvo con resina compuesta (sin base ni sellador superficial) y la utilización del sistema adhesivo autograbado.
Métodos para determinar el biotipo periodontal: Una revisión de la literatura
Authors: Tello Damián , Flores Carlos , Cañar Gabriela , Morocho Ángel
Published: December 2021

Para realizar varias intervenciones odontológicas es necesario una correcta evaluación del biotipo periodontal por la cual es necesario conocer los diferentes métodos de evaluación del biotipo periodontal. Se conocen 8 métodos para determinar el biotipo periodontal entre los que tenemos: visual, transparencia de sonda, evaluación transgingival, ultrasonido, tomografía computarizada, calibrador modificado, análisis fotográfico y tomografía computarizada de haz cónico. Hay varios métodos ampliamente usados para determinar el biotipo periodontal, sin embargo, entre los métodos analizados la tomografía computarizada de haz cónico posee una alta precisión y desviación mínima si lo comparamos con los métodos convencionales como la transparencia de sonda, evaluación transgingival o método visual para determinar con precisión el biotipo periodontal.
Rama del canalis sinuosus imitando una reabsorcion intrarradicular: reporte de caso
Authors: Ahumada-Tordecilla Daniela
Published: December 2021

El objetivo de este estudio es potenciar la importancia del conocimiento anatómico clínico de las estructuras que conforman el maxilar anterior, particularmente el canalis sinuoso y sus ramas accesorias y como dichas estructuras se presentan en los exámenes imagenológicos complementarios bi y tridimensionales como la radiografía periapical y la Tomografía Computarizada de Haz Cónico (CBCT). Se presenta un caso clínico de superposición de una rama accesoria del canalis sinousus que simula una reabsorción radicular interna. El análisis minucioso de cada caso clínico, junto al uso de las herramientas imagenológicas actuales nos permite establecer diagnósticos clínicos certeros y evitar tratamientos innecesarios.
Encuesta para valorar la percepción de los estudiantes de medicina veterinaria sobre las estrategias didácticas recibidas en su formación profesional en una universidad particular de Lima - Perú.
Authors: Rondón Herz Rodrigo , Echaiz Rodas Carlos-Augusto
Published: December 2021

El objetivo del estudio fue construir y validar una encuesta piloto, para medir la percepción de los estudiantes de medicina veterinaria acerca de las estrategias didácticas recibidas en su formación profesional, en la Universidad Peruana de Ciencias Aplicadas de Lima-Perú. El tipo de estudio fue observacional, descriptivo, y correlacional. El instrumento evaluó las dimensiones de la variable estrategias didácticas (percepción docente, cognitivos, procedimental y actitudinal). Asimismo, este cuestionario recibió la validación de contenido por medio del juicio de tres expertos, y se aplicó a 30 estudiantes, para verificar la redacción de los ítems. Luego se aplicó a una muestra de 137 estudiantes. La confiabilidad interna se definió a través de la determinación del Coeficiente de Alfa de Cronbach (CAC) Global (0,87) y para cada ítem. Además, se determinó la pertinencia de la aplicación del Análisis Factorial Exploratorio (AFE), por medio de la determinación del Indice kaiser Meyer Olkin (KMO= 0,65). Se realizó el Análisis de Componentes Principal y la gráfica de sedimentación, para determinar el número de factores a extraer. El AFE determinó que hay preguntas específicas que están correlacionadas tanto para cada indicador de cada una de las dimensiones de la variable estrategias didácticas como para cada uno de los cinco factores extraídos. Además, el CAC determinado por factor mostró un nivel de consistencia interna entre aceptable (0,66) y elevado (0,88), y la organización de la estructura factorial con rotación varimax, permitió identificar los indicadores por dimensión que pueden ser medidos para cada uno de los factores. De esta forma, las dimensiones que se miden por factor son:1) Percepción docente y procedimental; 2) Percepción docente, cognitivos y actitudinal; 3) Percepción docente y actitudinal; y 4) Cognitivo y procedimental.
Medición ultrasonográfica transversal del tendón flexor digital superficial (tendón perforante), flexor digital profundo (tendón perforado) y ligamento suspensorio (entrecuerda), del miembro torácico, en el Caballo Peruano de Paso, Lima-Perú
Authors: Craff Alexandra , Jimenez Eduardo
Published: December 2021

El objetivo del estudio fue describir las mediciones ultrasonográficas transversales del tendón flexor digital superficial (tendón perforante), tendón flexor digital profundo (tendón perforado) y ligamento suspensorio (entrecuerda), del miembro torácico, en el caballo Peruano de Paso, en Lima-Perú. Se evaluaron 30 ejemplares, hembras y machos, sin historial de lesiones tendinosas y/o ligamentosas. Se utilizó un ecógrafo marca Sono Scape ®, con un transductor lineal de 5-7 MHz para la evaluación ultrasonográfica. Se tomaron medidas del corte transversal en diferentes zonas de la región metacarpiana a una distancia determinada del hueso carpo accesorio. Se realizó la evaluación estadística de las medidas obtenidas para determinar una medida promedio de la raza. Se encontró que el caballo Peruano de Paso presenta tendones flexores y ligamento suspensorio del miembro toráxico más delgados que los caballos Anglosajones, caballos pesados no entrenados, caballos Pura Sangre Inglés entrenados, y Ponies. Se espera que estos resultados aporten información de referencia para la evaluación ultrasonográfica de las estructuras anatómicas en estudio del caballo Peruano de Paso, facilitando la evaluación objetiva de las lesiones a este nivel por parte de los médicos veterinarios.
ЕКОНОМІЧНА ТА ГУМАНІТАРНА СПІВПРАЦЯ УКРАЇНИ І ШВЕЙЦАРІЇ НАПРИКІНЦІ XVIII — У ПЕРШІЙ ЧВЕРТІ XX СТ.
Authors: Малюта О. В.
Published: December 2021

У статті вивчено еміграцію швейцарців наприкінці XVIII ст. — в першій чверті XX ст. в українські землі й те, як вони налагоджували там соціальне підприємництво, співпрацю у розвитку економіки, господарства, промисловості, військовій, медико-санітарній галузях. Зроблено висновок, що швейцарська еміграція в українські землі в досліджуваний період була системною, сприяла розвитку економіки, інфраструктури, формуванню нових населених пунктів, фермерських господарств, прискорювала модернізацію та індустріалізацію.

Ключові слова: Україна, Швейцарія, економічна співпраця, гуманітарна співпраця, українська державність, соборність.
НАУКОВО-ДОСЛІДНА ДІЯЛЬНІСТЬ ВИКЛАДАЦЬКОГО СКЛАДУ УНІВЕРСИТЕТІВ НАДДНІПРЯНСЬКОЇ УКРАЇНИ У ПЕРЕДРЕФОРМЕНИЙ ПЕРІОД ХІХ СТ.
Authors: Перегуда Є. В. , Пилипенко О. Є. , Лихолат А. О.
Published: December 2021

У статті досліджено зародження і становлення української науки в Київському та Харківському університетах. Всебічно розглянуто науково-дослідну діяльність професорсько-викладацького складу вищих навчальних закладів Наддніпрянської України першої половини ХІХ ст., різноманітних факторів, які сприяли цьому процесу. Доведено, що українські учені першої половини ХІХ ст. працювали у складних умовах занепаду та розкладання феодальної системи Російської імперії, реакційної політики уряду і царату. Професорсько-викладацький склад зазначених університетів зробив ґрунтовний внесок у становлення та розвиток математики, хімії, фізики, геології, палеонтології, анатомії, ботаніки, історії, лінгвістики та інших наук. Сформувалися наукові школи для підготовки висококваліфікованих фахівців з наведених галузей знань.

Ключові слова: університет, професорсько-викладацький склад, гуманітарні й технічні науки, наукове товариство, Університетські статути, наукове дослідження та розробка, Наддніпрянська Україна.
ВСТАНОВЛЕННЯ ВЛАДИ ДИРЕКТОРІЇ УКРАЇНСЬКОЇ НАРОДНОЇ РЕСПУБЛІКИ У ВІННИЦІ 19 ЛИСТОПАДА 1918 Р.
Authors: Кравчук О. М. , Кузьмінець Н. П.
Published: December 2021

У статті проаналізовано обставини встановлення влади Директорії Української Народної Республіки у Вінниці в контексті розгортання протигетьманського повстання 1918 р. Показано передумови, перебіг і наслідки повстання у Вінниці, що стала першим містом Поділля, де було встановлено владу Директорії УНР. Завдяки своєму значенню Вінниця перетворилася у важливий центр боротьби з гетьманатом, до міста прибула Директорія УНР і звідти керувала повстанням до успішного завершення.

Ключові слова: протигетьманське повстання, Поділля, Вінниця, Директорія УНР, Вінницька філія Українського національного союзу.
ЄВРОПЕЙСЬКИЙ ВЕКТОР У ЗМІНАХ В СИСТЕМІ ОХОРОНИ ЗДОРОВ’Я УКРАЇНИ 1991–2001 РР.
Authors: Дудник О. , Шауренко А. В.
Published: December 2021

У статті проаналізовано особливості розвитку охорони здоров’я в Україні у 1991–2001 рр. Показано, що економічна криза початку 1990-х рр. негативно вплинула на систему охорони здоров’я. В другій половині 1990-х рр. в медичній галузі намітилися позитивні зрушення, але значної динаміки не було досягнуто. Обґрунтовується висновок, що за окреслений у статті період в Україні не відбулося кардинального реформування системи охорони здоров’я.

Ключові слова: охорона здоров’я, медицина, медична допомога, державна політика, реформа.
Changes of Cognitive Ability and Circulatory Physiological Parameters Among Adolescents Moving From Altitudes of 3600 m to 500 m in China: A 50-Day Follow up Study
Authors: - Cirenyangzong , Gong Jianhong , - Dejiquzong , - Puzhen , - Luobuzhandui , - Awangdanzeng , - Danzengdunzhu , Chongsuvivatwong Virasakdi
Published: December 2021

Background: Travelling across altitude is increasing these days. The effects of travelling from high to low altitude on cognitive and physiological parameters of native highlander adolescents is not clear. The present study aimed to measure the changes of cognitive ability and circulatory physiological parameters when Tibetan adolescents move from high to low altitude, and to test the association between cognitive function change and changes in circulatory parameters.Method: General fluid intelligence, oxygen saturation, hemoglobin concentration, heart rate and blood pressure of 71 Tibetan adolescents were measured twice, initially at Lhasa city (altitude 3600 m) and again 50 days after arriving at Chengdu (altitude 500 m).Results: The mean intelligence scores remained unchanged when students moved from high to low altitude. However, the mean hemoglobin concentration, diastolic blood pressure and heart rate decreased while mean oxygen saturation and systolic blood pressure increased. No associations between change of intelligence and changes of circulatory physiological parameters were detected.Conclusions: Travelling from high to low altitude altered the mean value of circulatory physiological parameters but not cognition of Tibetan adolescents. Change of cognitive function was not associated with changes in physiological parameters.
Investigation Report on Influencial Factors of College Students' Innovation and Entrepreneurial Ability ---Taking Taizhou College of Nanjing Normal University as an Example
Authors: Gao Tianjing
Published: December 2021

Strengthening the cultivation of college students' innovation and entrepreneurial ability is not only the urgent need of the construction of national innovation system, but also the need to adapt to social development, alleviate employment pressure and cultivate innovative talents. Taking Taizhou College of Nanjing Normal University as an example, through the investigation of the influencing factors of College students' innovation and entrepreneurial ability and the situation of College students' innovation and entrepreneurial ability, the research group understands the current situation of College students' innovation and entrepreneurship education, and analyzes the key factors affecting college students' innovation and entrepreneurial ability, Finally, it puts forward some suggestions and measures to improve the innovation and entrepreneurial ability of college students.
Influence of Different Modified Gears on the Vibration and Noise of Electric Vehicle Reducer
Authors: Xu Bo , Qiu Yu , Yin Bifeng , Hua Xijun , Du Hang
Published: December 2021

The tooth profile crowning modification was applied onto paired gears for reducing the noise of an electric vehicle reducer. The simulated gear contact spots are compared before and after modification, and are validated by a contact spot experiment. Based on the rigid-flexible coupling model of the gear transmission system, the time-varying meshing stiffness, time-varying meshing force, and the vibration and noise of the gear pairs with different modified gears obtained by simulating calculation are analyzed. The results showed that the selection of modified gear has a great influence on the modification effect. In the way of tooth profile crowning, it is not advisable to modify the pinion independently, as it may increase the frequency and degree of meshing impact between the helical gear pair, making the transmission become less smooth; while modifying the wheel and pinion at the same time can effectively reduce the time-varying meshing stiffness and force, and the vibration and noise. Also, the optimized gear modification scheme is verified by the noise test.
COMPUTATIONAL ASSISTANCE: newsbot development for financial organizations
Authors: Marques Alberto , Barroso Suélem S. P.
Published: December 2021

This research aims to develop the Minimum Viable Product (MVP) of a cloud platform that transforms structured data into automated text, to enhance the production of content in Brazilian stock brokerage companies. It  is based on applied research that combines different techniques for the development of MVP. As a theoretical path to support product development, it permeates strategic communication in corporations, as well as the adoption of algorithms and content automation in journalistic production. Among the results achieved, the work presents the logic of infrastructure of macro operation for the newsbot and the main elements for the many layers of development that an application of this nature needs.
A AUTONOMIA CIENTÍFICA DO CONTROLE ABSTRATO DE CONSTITUCIONALIDADE E SUA APLICAÇÃO PELO SUPREMO TRIBUNAL FEDERAL
Authors: Nunes Danilo Henrique , Silvestrini João Pedro , Ferreira Olavo Augusto Vianna Alves
Published: December 2021

Este trabalho consiste em uma pesquisa acerca da autonomia do controle abstrato, em virtude de sua natureza objetiva. Nesse sentido, o objetivo pretendido é a discussão referente à subsistência da autonomia científica do controle abstrato de constitucionalidade e investigar sua aplicação pelo Supremo Tribunal Federal. A fiscalização normativa abstrata visa a tutela da ordem constitucional, não se vinculando a uma situação jurídica de caráter individual ou concreto. Assim, não se mostra conveniente o emprego de normas subjetivas a um processo objetivo, pois ocasionaria na utilização de normas processuais impertinentes e, consequentemente, impróprias. Portanto, em decorrência da especificidade e da consequente independência do processo objetivo, constata-se a existência da autonomia científica da fiscalização abstrata de constitucionalidade. Esse é o entendimento adotado pelo Supremo Tribunal Federal, conforme o julgado nas Ações Direitas de Inconstitucionalidade nº 1.254/RJ, nº 3.345/DF e nº 2.422/DF. Logo, mediante uma pesquisa dedutiva, baseada em estudos na jurisprudência do Supremo Tribunal Federal, na doutrina e ao anteprojeto de Código de Processo Constitucional (assumido pela Ordem dos Advogados do Brasil), o presente trabalho sustentará a tese referente à emancipação do direito processual constitucional abstrato.
Key Rate and Loan Market in Russia
Authors: Borodachev S. M.
Published: December 2021

The paper proposes a mechanism for the impact of changes in the key rate on the volume of newly issued loans. The volume depends on the price (interest rates on loans), and the price depends on the key rate and the actual consumption of loans in the previous period (generalized cobweb cycle). The model was estimated by a Kalman filter, adequacy was confirmed by simulation. It is possible to forecast the average rate on loans for a month in advance according to the information published by the Central Bank of the Russian Federation (CB). By playing various scenarios for changing the key rate, it was found that in quiet periods of economic development, the usual laws of supply and demand operate in the loan market and by raising the key rate, you can reduce inflation. In the turbulent (overheated) state of the economy, an increase in the key rate can, on the contrary, provoke an increase in the issuance of loans and unconventional manipulations with the key rate are required.
Atypical Roles of the Chemokine Receptor ACKR3/CXCR7 in Platelet Pathophysiology
Authors: Chatterjee Madhumita
Published: December 2021

The manifold actions of the pro-inflammatory and regenerative chemokine CXCL12/SDF-1α are executed through the canonical GProteinCoupledReceptor CXCR4, and the non-canonical ACKR3/CXCR7. Platelets express CXCR4, ACKR3/CXCR7, and are a vital source of CXCL12/SDF-1α themselves. In recent years, a regulatory impact of the CXCL12-CXCR4-CXCR7 axis on platelet biogenesis i.e. megakaryopoiesis, thrombotic and thrombo-inflammatory ac-tions have been revealed through experimental and clinical studies. Platelet surface expression of ACKR3/CXCR7 is significantly enhanced following myocardial infarction (MI) in acute coro-nary syndrome (ACS) patients, also associated with improved functional recovery and progno-sis. The therapeutic implications of ACKR3/CXCR7 in myocardial regeneration and improved recovery following an ischemic episode, are well documented. Cardiomyocytes, cardi-ac-fibroblasts, endothelial lining of the blood vessels perfusing the heart, besides infiltrating platelets and monocytes, all express ACKR3/CXCR7. This review recapitulates ligand induced differential trafficking of platelet CXCR4-ACKR3/CXCR7 affecting their surface availability, and in regulating thrombo-inflammatory platelet functions and survival through CXCR4 or ACKR3/CXCR7. It emphasizes the pro-thrombotic influence of CXCL12/SDF-1α exerted through CXCR4, as opposed to the anti-thrombotic impact of ACKR3/CXCR7. Offering an innovative translational perspective, this review also discusses the advantages and challenges of utilizing ACKR3/CXCR7 as a potential anti-thrombotic strategy in platelet associated cardiovascular dis-orders, particularly in coronary artery disease (CAD) patients post-MI.
An Integrated Epigenomic and Genomic View on Phyllodes and Phyllodes-Like Breast Tumors
Authors: Hench Juergen , Vlajnic Tatjana , Soysal Savas Deniz , Obermann Ellen C , Frank Stephan , Muenst Simone
Published: December 2021

Fibroepithelial lesions (FL) of the breast, in particular Phyllodes tumors (PT) and fibroadenomas, pose a significant diagnostic challenge. There are no generally accepted criteria that distinguish benign, borderline, malignant PT, and FA. Combined genome-wide DNA methylation and copy number variant (CNV) profiling is an emerging strategy to classify tumors. We compiled a series of patient-derived archival biopsy specimens reflecting the FL spectrum and histological mimickers including clinical follow-up data. DNA methylation and CNVs were determined by well-established microarrays. Comparison of the patterns with a pan-cancer dataset assembled from public resources including "The Cancer Genome Atlas" (TCGA) and "Gene Expression Omnibus" (GEO) suggests that FLs form a methylation class distinct from both control breast tissue as well as common breast cancers. Complex CNVs were enriched in clinically aggressive FLs. Subsequent fluorescence in situ hybridization (FISH) analysis detected respective aberrations in the neoplastic mesenchymal component of FLs only, confirming that the epithelial component is non-neoplastic. Of note, our approach could lead to the elimination of the diagnostically problematic category of borderline PT and allow for optimized prognostic patient stratification. Furthermore, the identified recurrent genomic aberrations such as 1q gains (including MDM4), CDKN2a/b deletions and EGFR amplifications may inform therapeutic decision-making.
EXPERIMENTAL METHODS FOR STUDYING THE RESOURCE VALUE OF DUMP BLAST FURNACE SLAGS
Authors: Datsenko Vita , Shulichenko Olena , Khobotova Elina
Published: December 2021

The study of the properties of blast-furnace slags requires an integrated approach, including various research methods. The purpose of the work is to substantiate the resource value of the Zaporizhstal dump blast furnace slag. The research methods were used: X-ray phase, petrographic, gamma-spectrometric analysis and electron probe microanalysis. The slag is dispersed into fractions, since the slag minerals have different hardness. Fractions (mm) were investigated in the work: >20 2.5–5, <0.63. X-ray phase analysis made it possible to reveal in the crystalline part of blast-furnace slag minerals that are technically valuable in the production of binders: 3CaO∙2SiO2, SiO2, 2CaO∙Al2O3∙SiO2, α-2CaO∙SiO2, 2CaO∙MgO∙2SiO2, α-CaO∙SiO2. Minerals akermanite, bredigite, pseudo-wollastonite have hydraulic activity. It is shown that the mass fraction of the amorphous component is half the mass of the blast furnace slag. The high content of substances in the amorphous state confirms the possibility of sorption of extraneous ions and compounds. The found elements Potassium, Sodium, Sulfur, Chlorine, Cuprum and Titanium are not part of the minerals. Slag contains less than 1% of the total amount of Fe, Ti and Cu, belonging to the 3rd class of hazardous substances. The maximum content of Potassium, Sodium and Titanium is typical for the fraction 2.5–5 mm. The most basic is the fraction <0.63 mm (pH 9.7), for the 2.5–5  mm fraction pH 9.1, the most acidic fraction >20 (pH 8.2). By the value of the toxicity index (4.3–5.4) and the III hazard class, dump blast furnace slag «Zaporizhstal» as a moderately hazardous waste can be used as a secondary raw material in the construction industry. The database on the content of natural radionuclides in technogenic raw materials has been updated. It has been proven that slag and its individual fractions contain natural radionuclides 40К, 226Ra, 232Th. The main contribution to the value of Сef is made by the 226Ra radionuclide, then by 232Th. The excess of specific activity is expressed for the 2.5–5 mm fraction. The I class of radiation hazard is defined, which allows the use of slag in construction without restrictions. Dump blast furnace slag «Zaporizhstal can be recommended in the production of inorganic binders « by the totality of chemical indicators.
SEARCH FOR WAYS OF CONTROLLED MODIFICATION OF CHARACTERISTICS OF FUNCTIONAL UNITS OF ADAPTIVE AIR PURIFICATION SYSTEMS
Authors: Dryuchko Oleksandr , Bunyakina Natalia , Korobko Bogdan , Shefer Oleksandr , Kytaihora Kateryna , Ivanytska Iryna
Published: December 2021

Information on alkaline coordination nitrates of rare-earth elements of the cerium subgroup - precursors of promising modern multifunctional materials - on the conditions of their formation and existence, the nature of the chemical bond, the composition, structure, shape of the Ln coordination polyhedra, the type of ligand coordination, and the existence of isotypic series in stoichiometry are generalized. composition, structure, characteristic properties. The data obtained (as primary information) is the basis for the detection, identification, and control of the phase state of processing objects in the preparatory stages, the choice of criteria for the compatibility of the components in the formation of single-layer and layered nanostructured oxide composite systems of lanthanides and transition elements for general purposes, with catalytic and photocatalytic activity, coatings self-cleaning with hydrophilic properties; development of various combined methods for their activation and identification of technological functional dependencies; controlled modification of the properties of the obtained target products. To increase the photocatalytic activity of coating samples based on highly dispersed anatase TiO2, a methodology for chemical modification of oxidation centers in their surface layer with heat treatment in contact with thermolysis products of alkaline coordination lanthanide nitrate melts is proposed. An effective test photocatalytic destruction of organic substrates vapors has been discovered using ethanol as an example.Effective activation of the functioning of functional units in the composition of self-adjusting air purification complexes using new photocatalytically active three-layer perovskite-like oxide materials M2Ln2Ti3O10 (M - Li, Na, K; Ln - La, Nd) has been proven. The variability of such methods for creating and modifying the characteristics of polyfunctional coatings is determined by the number and individual properties of representatives of the natural series of lanthanides, alkali metals of the periodic system, the peculiarities of their cooperative behavior in the preparatory technological stages, conditions and methods of activation of formation processes, the nature of the substrate, and other factors.
DEVELOPMENT OF RESOURCE-SAVING TECHNOLOGY OF POROUS-HOLLOW CERAMIC STONES
Authors: Shchukina Liudmyla , Hamova Olha , Herasev Maksym
Published: December 2021

A resource-saving technology of porous ceramic materials using low-quality non-sintering sandy loam as a basic raw material has been developed. Based on the analysis of the plastic properties of two- and three-component ceramic masses, including sandy loam, expanded clay and fuel slag in various ratios, it was found that the required level of their plasticity provides the content of the main raw material in the following range (wt%): fuel slag – 15 – 20; sandy loam – 50 – 65; expanded clay – 20 – 30. By the method of planning the experiment, the rational composition of the three-component ceramic mass was substantiated. This which contains: 62.5 wt.  % sandy loam, 20 wt. % medium-sintering plastic clay as a plasticizer and 17.5 wt. % fuel slag of TPP as a porous agent. For the developed mass, the main technological properties were investigated, which made it possible to recommend the drying mode of the raw material – 60 hours, the optimal firing temperature – 950 °С. Such conditions ensure that samples are obtained without drying cracks and signs of deformation. Оn the results of dilatometric analysis of mass  the rational mode of firing high-hollow semifinished products was designed. The firing mode provides for a 44-hour firing and a decrease in the heating rates in the areas of dehydration of clay minerals, direct quartz transition and intensive sintering of the mass, as well as a decrease in the cooling rate in the area of the reverse quartz transition. The proposed firing mode provides the degree of sintering and their properties necessary for ceramic materials. Based on the developed mass under the recommended drying and firing modes, porous ceramic materials with an apparent density of 1.48 g/cm3, a compressive strength of 18.2 MPa and frost resistance of 30 cycles were obtained. The developed materials belong to the group of conditionally effective, and if 50% of the voids are organized, they can be classified as effective.
ANTIMICROBIAL SCREENING OF HETEROPHRAGMA ADENOPHYLLUM EXTRACTS AND EFFECTS OF LIGHT IRRADIATION
Authors:   Sajid Bashir, Shoaib Akhtar Muhammad
Published: December 2021

Medicinal plants have considerable widespread use as crude drugs in the primary health care of communities. Various plants have already been tested for their antimicrobial activity to discover new antimicrobial agents. In this investigation antimicrobial activities of aqueous and methanolic extracts of Heterophragma adenophyllum leaves and seeds were screened as these have been used since centuries in traditional medicine for the treatment of skin and urinary tract infections and also as antidiarrheol and antidiabetic agents
THE DOMESTICATED DONKEY:II -TYPES AND BREEDS
Authors:   Saim Boztepe, Yilmaz Orhan
Published: December 2021

In this study many types and breeds were revised including wild donkeys and domestic breeds from various countries of the world.The donkey, or ass, is the smallest species in the family Equidae. Itis known for its exceptionally long ears. The word â€˜donkey' refers to the domesticated Equus asinus. The wild ancestor of donkey is equally deemed to be Equus asinus, the African Wild Ass.
Structural‑phase composition of a gas‑thermal coating of Fe‑Cr‑Ni‑Al pseudo alloy subjected to annealing
Authors: Belotserkovsky М. A. , Kukareko V. A. , Korobov Yu. S. , Astrashab E. V. , Grigorchik I. I.
Published: December 2021

The structural‑phase state of the gas‑thermal coating made of Fe‑Cr‑Ni‑Al pseudo‑alloy in the initial state, as well as after annealing in the temperature range 550–650 °C for 20–60 minutes, has been investigated. It has been established that the phase composition of the Fe‑Cr‑Ni‑Al pseudo‑alloy in the initial state includes mainly Al and α‑Fe, and its porosity does not exceed 3–5 vol.%. Annealing of a thermal spray coating from a pseudo‑alloy at temperatures of 550–650˚C for 20–60 minutes leads to the release of iron‑aluminum intermetallic compounds Fe3Al, Al13Fe4 and Al5Fe2, an increase in hardness and porosity.
Selection of the chemical composition of steels and their thermal hardening mode using a computer program
Authors: Berdiev D. M. , Uмаrоvа M. A. , Yusupov A. A.
Published: December 2021

The relationships between the parameters of the structure of heat‑treated steels and their abrasive wear resistance are established. At all temperatures of the final tempering of hardened steel, there is a direct relationship between its structure parameters (the number of elements in a solid solution, the density of dislocations, the size of cementite particles and the intercementite distance) and wear resistance when sliding friction against loose abrasive particles. A computer program has been developed to select the chemical composition of the steel grade and methods of thermal hardening in order to ensure the required wear resistance.
Compositionally Disordered Doped with Cerium Crystalline Garnet Type Materials for Brighter and Faster Scintillations
Authors: Korzhik M. V.
Published: December 2021

Ce-doped tetracationic garnets (Gd, M)3Al2Ga3O12(M = Y, Lu) form a family of new multipurpose promising scintillation materials. The aim of this work was to evaluate the scintillation yield in the materials of quaternary garnets activated by cerium ions with partial isovalent substitution of the matrix-forming gadolinium ions by yttrium or lutetium ions.Materials were obtained in the form of polycrystalline ceramic samples, and the best results were shown by samples obtained from the raw materials produced by the coprecipitation method. It was found that ceramics obtained from coprecipitated raw materials ensure a uniform distribution of activator ions in the multi-cationic matrices, which enables the high light yield and fast scintillation kinetics of the scintillation. It was demonstrated that the superstoichiometric content of lutetium/gadolinium in the material is an effective method to suppress phosphorescence accompanied scintillation. For ceramics with the composition (Gd, Lu)3Al2Ga3O12 , a scintillation yield of more than 50.000 ph/MeV was achieved. The scintillation kinetics was measured to be close to the kinetics with a decay constant of 50 ns.In terms of the set of the parameters, the developed scintillation materials are close to the recently developed alkali halide materials LaBr3:Ce, GdBr3:Ce. Moreover, they have high mechanical hardness, are characterized by the absence of hygroscopicity, and are better adapted to the manufacture of pixel detectors used in modern devices for medical diagnostics.
Shell Rounds the Corner on a Whale of a Task
Authors: Wright Blake
Published: December 2021

Shell had a problem. It had just spent billions to bring its Appomattox find on line in the deepwater Gulf of Mexico (GOM). That development featured the oil giant’s eighth and largest floating platform in the region. The host semisubmersible weighed 125,000 metric tons—more than the largest aircraft carrier.

Shell lauded its ability to reduce project cost by 40%, based on experience gained from the development of its previous four-column production platforms in the US Gulf, including the Olympus tension-leg platform. It would transfer these learnings to its next project—the Vito find in about 4,000 ft of water, 150 miles southeast of New Orleans. The field could hold up to 300 million BOE.

At the same time the plans for Vito were being laid out, shale projects leapt to the forefront in the competition for capex dollars, and due to the comparative investment, they were winning. Industry success across the nation’s shale plays helped flood the market with oil, forcing the price per barrel down. Suddenly, spending big money on megaprojects offshore had lost much of its luster. For the US Gulf to reclaim at least some of its competitive advantage, fields could no longer be developed with massive, high-dollar facilities. A management mandate dictated that a new minimal, repeatable solution be found. After several years of study, a favorite emerged.

“The original concept of Vito was much larger,” said Kurt Shallenberger, Vito project manager for Shell. “The development was probably similar in size to the Appomattox project that Shell recently completed—a 40,000-ton topsides, and a 50-year field life with a sizable gas-reinjection component to it.”

Shell’s method for arriving at the new development scheme was dubbed “Minimal Technical Scoping”—the company would start with the absolute minimum scope and then justify additions upward. The project mantra was “Simpler is safer.” The results were a simplified topsides design as well as streamlined mooring systems for the host facility.

“The redesign took it down to what I call the sweet spot of semisubmersibles—around a 10,000-ton deck,” said Shallenberger. “You had seen examples of that with LLOG’s Delta House, Independence Hub, and others like that. That was the sweet spot to where multiple fabricators can build it, multiple yards can integrate it, multiple companies can install it—and you can generally get 100,000 bbl a day through it. Now you’re in a competitive environment for all the vendors rather than just the one guy in the world who can do this. That’s what really created the opportunity for Vito. We shrunk the size and scope down to a point where it could get to a breakeven price that is competitive with the onshore folks.”

According to Shell, the breakeven price for their minimal floater design is less than $35/bbl.

Shell locked up key vendors for Vito. Jacobs Engineering Group carried out the detailed engineering and front-end engineering design studies for the Vito topsides. Sembcorp would build the host and integrate the topsides and hull at its Tuas Boulevard yard in Singapore.
A New Recipe for Friction-Reducer Suppliers: Polymer Plus Frac Water, Minus the Cost
Authors: Rassenfoss Stephen
Published: December 2021

The argument for making friction reducer on site is simple: only one truck is required to deliver dry polymer vs. three loads required for the same amount of liquid additive.

For Downhole Chemical Solutions (DCS), reducing the number of trips and the amount of chemicals needed to create a stable liquid by mixing it as needed on site reduces the average cost of a gallon of friction reducer by around 30%, said Mark Van Domelen, vice president of technology for DCS.

“The business is very cutthroat and competitive on the pricing of polyacrylamide. We can reduce the cost further on friction reducer,” using dry polymer, he said.

Polyacrylamide is generally described as the key component in friction reducers. Suppliers also add some ingredients to create a stable liquid and others that are supposed to improve performance. When DCS delivers dry polymer to a well pad to mix it on-site, the only other ingredient is water provided by the customer.

It has been a winning strategy change for the private company; it has grown rapidly, even during last year’s slump. DCS increased the number of mixing units from one to 16, and dry polymer sales have grown from 10% to 90%, Van Domelen said.

One of the company’s customers is John Blevins, the chief operating officer for Houston-based Hibernia Resources III and an early adopter who was a lead author of a paper on making friction reducer on site while fracturing (SPE 204176).

Blevin, who uses the words “friction reducer” and “polymer” interchangeably, is the rare C-level executive who likes to manage operations from a frac van at a company that normally completes one pad at a time.

The polymer is polyacrylamide. When Blevin works with DCS on a well, he purchases it directly from one of the few chemical companies that will produce the polymer based on his specifications. The price on the DCS invoice will be a price per pound that covers the cost of the polymer and the service.

At Hibernia, a small private-equity and employee-owned company, there is a powerful incentive to pay close attention to the details.

“When we spend a nickel, that nickel is divided among us at some point in time. If we are efficiently frugal, we are going to be better off in the long run,” Blevins said.

The paper, which was presented at the Unconventional Resources Technology Conference (URTeC), included a chart showing stage-by-stage costs, with the average cost for dry stages ranging from 27% to 31% lower than similar stages that were fractured using liquids.

The simplicity of the mix is a plus for Blevins whose company is especially focused on how chemicals are likely to react downhole.

“We did a 6-month study before we pumped anything in the ground to make sure we had the right combination” of fracturing additives, he said. “We do study nearly every well and every landing zone to ensure the chemicals used are compatible.”
Integrated Work Flow Delivers Precise Properties Input for Unconventional Simulation
Authors: Carpenter Chris
Published: December 2021

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203374, “Is My Completions Engineer Provided With the Correct Petrophysical and Geomechanical Properties Inputs?” by Philippe Gaillot, Brian Crawford, and Yueming Liang, SPE, ExxonMobil, et al., prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed.

To simulate the performance of unconventional wells effectively, incorporating sufficient geological complexity is essential to allow for realistic variability in the petrophysical and mechanical properties controlling the productivity of the effective stimulated rock volume (ESRV). The complete paper presents an integrated work flow to model mechanical properties at sufficiently high resolution (centimeter scale) to accurately honor rock fabric and its height and complexity effects on hydraulic fracturing and, therefore, on production. Once upscaled, outputs of this work flow enable a more-realistic borehole view of reservoir quality, fluid-flow units, and geomechanical stratigraphy, all information key to optimal asset development.

Introduction

Simulating hydraulic fractures with pre-existing natural mechanical discontinuities remains an important challenge. In most cases, the trend is to include more details in the simulations and apply more computational power to solve the problem. While these complex numerical simulations allow simultaneous interaction between multiple phenomena, the validity of the predicted hydraulic fractures, and thus ESRV productivity, may be questionable if inputs to the hydraulic-fracturing and production models do not capture the effective fine-scale complexity of the formation properties, namely the minimum in-situ horizontal stress contrast between layers, the changing layer properties, and the mechanical and flow properties of the interfaces.

The complete paper presents a seven-step work flow wherein core poroelastic anisotropies derived from quantitative mineralogy and well-established micro-mechanical theory are integrated into a high-vertical-resolution multiphysics petrophysical model able to capture the centimeter-scale level of heterogeneity observed from cores. The resulting high-vertical-resolution well frame-work enables a detailed well-scale calibration and recognition of facies and stacking patterns; an accurate and core-calibrated geochemical, petrophysical, and geomechanical characterization of individual beds; and an identification and characterization of the interfaces between beds.
Association Between Chinese Herbal Medicine (CHM) Treatment and Depression Among Cancer Patients in a Cross-sectional Study
Authors: Lin Huiyue , Zhang Xueting , Zhang Yi , Cui Wenjing , Jia Fang , Wang Juyong
Published: December 2021

Aim: This study was undertaken to investigate the relationship between Chinese Herbal Medicine treatment and depression in cancer patients. Methods: A cross-sectional study was conducted among cancer outpatients at Longhua Hosiptal Shanghai University of Traditional Chinese Medicine from June 2020 to April 2021; Ethical approval number:2020LCSY057). All patients signed informed consent and completed The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. Hamilton depression scale was evaluated depression by psychiatrists. The software packages R and EmpowerStats were used for statistical analysis.Results: 374 was enrolled in Received Chinese Herbal Medicine treatment group and 435 was enrolled in Non-received Chinese Herbal Medicine treatment group. The assessment results of Hamilton depression scale and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire in Received Chinese Herbal Medicine treatment group were better than Non-received Chinese Herbal Medicine treatment group. After adjusting potential confounders (gender, medical insurance, cancer stage, et al), Chinese Herbal Medicine treatment indicated negative correlation with depression (OR=0.7, 95% confidence interval (CI): 0.5 to 0.9). The interactions in each subgroup were no significantly effect on the relationship between Chinese Herbal Medicine treatment and depression.Conclusion: Chinese Herbal Medicine treatment was an independent protective factor for depression in cancer patients, and lead to better quality of life for cancer patients.