bluuebunny/crossref_metadata_2025 huggingface dataset:
Pyrolysis yields of tobacco crop residue as a potential alternative fuel source
Authors:   Department of Mechanical Engineering, Energy Conversion, Brawijaya University, Malang, Indonesia, Wijayanti Widya , Sasongko Mega Nur ,   Department of Mechanical Engineering, Energy Conversion, Brawijaya University, Malang, Indonesia, Musyaroh Musyaroh ,   Department of Mechanical Engineering, Energy Conversion, Brawijaya University, Malang, Indonesia
Published: May 2021

This study aims to utilize the tobacco crop residue to generate a high economic value for the energy sector. In general notion, tobacco crop is burned as a conventional fuel at low prices; however, in this research, tobacco crop residue was processed through pyrolysis in the form of pyrolysis products (liquid and solid yields) providing a promising alternative fuel fulfilling the standardized fuel properties. The pyrolysis was conducted at a laboratory-scale real pilot plant experiment at a fixed bed reactor and was operated at temperature of around 350 °C to 650 °C for 2 hours to navigate the most optimum product. Further, the products comprising char (solid yield) and tar (liquid yield) were investigated by measuring their properties, which include heating value, flash point, viscosity, density, and char yields’ morphology. The measurement results indicated that the heating value of tobacco crop residue from pyrolysis process significantly escalated to 300% compared to that of tobacco crop residue before pyrolysis process. Similarly, several tar properties indicated the liquid fuel standard such as kerosene. Additionally, another product in the form of solid yields is proved to be utilized as a smart material besides having a higher heating value over coal, due to the high-quality carbon specifications. However, further processing is encouraged to navigate the possibility of solid yields into activated carbon.
Optimal forecasting of thermal conductivity and storage in parabolic trough collector using phase change materials
Authors:   Associate Professor Department of Mechanical Engineering, Saintgits College of Engineering Kottukulam Hills, Pathamuttom, Kottayam, Kerala, Muruganantham P. , Dhanapal Balaji ,   Professor, Department of Mechanical Engineering, Hindustan Institute of Technology & Science, Padur, Kelambakam, Chennai, Tamil Nadu
Published: May 2021

Renewable energy is one of the cleaner energy generation strategies practiced all over the world to reduce environmental impacts and waste based on current sustainability in economic practices. Solar energy is one kind of renewable sources of energy practiced for different application. The thermal storage system in solar energy is one of the least practiced methods in research, and the utilization of solar energy in the thermal application is attaining higher responses and is quite possible. In this paper, solar heat generation is attained by solar parabolic trough collector using phase change materials. The ideology behind this research is to develop a thermal energy storage system using solar collectors and phase change materials. A composition mixture of MgCl2. 6H2O phase change materials used as the fluid medium in trough collector and thermal efficiency of the material is evaluated. For effective optimization, an imperialist competitive algorithm is used for optimizing the thermal efficiency of the solar collectors. The thermal efficiency of the collector is numerically experimented in the running platform of Mat Lab and executed in terms of heat gain, heat loss, and thermal efficiency of the parabolic trough collector, respectively. The efficiency of the proposed framework is 85%, and the current framework just has 80% efficiency. The heat loss in the proposed framework is lower than that of the current system, distinguished as 4200 W and 4520 W, respectively. It is shown from the research study that the proposed PCM composition is an optimal method for generating heat energy in solar parabolic trough collectors.
Half-hour global solar radiation forecasting based on static and dynamic multivariate neural networks
Authors:   Department of Physics, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco, Jallal Mohammed Ali , Chabaa Samira ,   Industrial Engineering Department, National School of Applied Sciences, Ibn Zohr University, Agadir, Morocco, Zeroual Abdelouhab ,   Department of Physics, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
Published: May 2021

Precise global solar radiation (GSR) measurements in a given location are very essential for designing and supervising solar energy systems. In the case of rarity or absence of these measurements, it is important to have a theoretical or empirical model to compute the GSR values. Therefore, the main goal of this work is to offer, to designers and engineers of solar energy systems, an appropriate and accurate way to predict the half-hour global solar radiation (HHGSR) time series from some available meteorological parameters (relative humidity, air temperature, wind speed, precipitation, and acquisition time vector in half-hour scale). For that purpose, two intelligent models are developed: the first one is a multivariate dynamic neural network with feedback connection, and the second is a multivariate static neural network. The database used to build these models was recorded in Agdal’s meteorological station in Marrakesh, Morocco, during the years of 2013 and 2014, and it was divided into two subsets. The first subset is used for training and validating the models, and the second subset is used for testing the efficiency and the robustness of the developed models. The obtained results, in terms of the statistical performance indicators, demonstrate the efficiency of the developed forecasting models to accurately predict the HHGSR parameter in the city of Marrakesh, Morocco.
Mechanical behavior of a lower limb prosthetic socket made of natural fiber reinforced composite
Authors:   Al Ahsa College of Technology, Technical and Vocational Training Corporation, Saudi Arabia, Mankai Wahbi , Brahim Sami Ben ,   Laboratory of Materials, Optimization and Energy for Sustainability, National Engineering School of Tunis, University of Tunis, El Manar, BP 37, Le Belvedere 1002 Tunis, Tunisia, Smida Brahim Ben ,   Laboratory of Civil Engineering, National Engineering School of Tunis, University of Tunis, El Manar, BP 37, Le Belvedere 1002 Tunis, Tunisia, Cheikh Ridha Ben ,   Laboratory of Materials, Optimization and Energy for Sustainability, National Engineering School of Tunis, University of Tunis, El Manar, BP 37, Le Belvedere 1002 Tunis, Tunisia, Chafra Moez ,   Applied Mechanics and Systems Research Laboratory, Tunisia Polytechnic School, University of Carthage, BP 743, La Marsa 2078, Tunisia
Published: May 2021

Transtibial sockets are commonly made of composites reinforced with expensive synthetic fibers such as carbon or glass fibers. It would be very beneficial to replace conventional fibers with the natural ones produced locally using an abundant wild plant like alfa (Stipa tenacissima) fiber that is economically sustainable and environmentally friendly. This work is aimed at studying the static and dynamic behavior of transtibial sockets produced from alfa and carbon fibers. The ultimate strength obtained during the static test on the carbon fiber socket and the alfa fiber socket is 3,400 and 2,900 N, respectively. Fatigue testing on the alfa fiber socket yielded a fatigue life of about 2,325,000 cycles. Locally produced alfa fibers could be used as reinforcement of composite materials in orthopedic applications such as transtibial sockets. This could make prosthesis more affordable and serve as basis for design of new standard sockets as a result of fatigue and strength data. Further mechanical viability study should be performed to ensure the feasibility of using alfa fibers in sockets.
A new mathematical model to cover crew pairing and rostering problems simultaneously
Authors:   Dep. of Industrial Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran, Saemi Saeed , Komijan Alireza Rashidi ,   Dep. of Industrial Engineering, Firoozkooh Branch, Islamic Azad University, Firoozkooh, Iran, Tavakkoli-Moghaddam Reza ,   School of Industrial Engineering, College of Engineering, University of Tehran, Tehran, Iran, Fallah Mohammad ,   Dep. of Industrial Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
Published: May 2021

Crew scheduling problem includes two separate subproblems, namely, crew pairing and crew rostering problems. Solving these two subproblems in a sequential order may not lead to an optimal solution. This study includes two main novelties. It combines these two subproblems and presents them in a single model. On the other hand, despite previous researches that considered a pairing continuously, the proposed model benefits from the capability of considering one or more days off in a pairing assigned to a crew member. This is extremely useful as it enables the crew to participate in required courses, doing medical checks, etc. Two solution approaches, namely, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), are used to solve the model. Eventually, the performance of the proposed algorithms is evaluated. Both ended to satisfactory results; however, PSO relatively outperformed GA in terms of solution optimality and computational time.
Expert solution for effects of input parameters on multiphase flow correlations
Authors:   Amal Petroleum Company, Cairo, Egypt, El-Moniem Mohamed A. Abd , El-Banbi Ahmed H. ,   The American University in Cairo, Cairo, Egypt
Published: May 2021

Oil and gas production represents an essential source of energy. Optimization of oil and gas production systems requires accurate calculation of pressure drop in tubing and flowlines. Many empirical correlations and mechanistic models exist to calculate pressure drop in tubing and flowlines. Previous work has shown that some correlations provide more accurate results under certain flow conditions, PVT data, and well configurations than others. However, the effects of errors in input data on the selection of which correlations to use have not been investigated. This paper studies different multiphase flow correlations to determine the effects of their input parameters on (1) the accuracy of calculated pressure drop and (2) the selection of best correlation. A database consisting of 33 oil wells and 32 gas wells was selected, and a commercial software was used to build different well models. A total of 715 well models were constructed and used to investigate the effects of errors in correlations inputs on both the calculated bottomhole pressure and the selection of best correlation(s). The methodology was based on perturbing the values of the selected input parameters and calculating the new predicted bottomhole flowing pressure. Then, the effects of error in input parameters on how the calculated bottomhole pressure was different from observed data were quantified. The effect of this error in input parameters was also checked against the algorithm that selects the best correlation(s). It was found that errors in input GOR have the greatest effects for oil wells, while gas specific gravity and the tubing roughness are the most effective parameters for gas wells. The results were integrated into a rule-based expert system. A new set of data, consisting of 220 cases from 10 new oil wells and 10 new gas wells, was used to validate the expert system. The expert system was found to predict the best correlation(s) with a success rate of 80%, and it also identifies the input parameters whose error would affect the value of calculated bottomhole pressure significantly. Finally, the rules of the expert system were programmed into a VBA-Code to ease its use.
Optimal design of tricept parallel manipulator with particle swarm optimization using performance parameters
Authors:   Mechanical Engineering, Khwaja Fareed University of Engineering and Information Technology Rahim Yar khan, Farooq Syed Saad , Baqai Aamer Ahmed ,   Mechanical Engineering, National University of Sciences and Technology Rawalpindi, 46000, Pakistan, Shah Muhammad Faizan ,   Mechanical Engineering, Khwaja Fareed University of Engineering and Information Technology Rahim Yar khan
Published: May 2021

The parallel manipulators are skilled for their precision manufacturing but need optimized design to get maximum dexterity that will lead towards better industrial production rates. The 3-DOF tricept is chosen to utilize its maximum capabilities for its functionality. Three performance parameters conditioning index, workspace volume, and global conditioning index are used to obtain optimum design variables of tricept mechanism. With a view to compare them in terms of processing effort, particle swarm optimization (PSO) is applied here. Finally, multiobjective optimization with two strategies weighted and epsilon constraint is performed to control the different parameters simultaneously and also to give validation of previously obtained GA based optimum design values of tricept mechanism.
Quantification label for mobile apps
Authors:   Department of Computer Engineering, Kuwait University, Kuwait, Habib Sami J. , Marimuthu Paulvanna N. ,   Department of Computer Engineering, Kuwait University, Kuwait
Published: May 2021

Nowadays every product we purchase has a tag informing its users how much an automobile or an appliance will cost to run and how much energy a food product will provide on consumption, for example. With the advent of Internet, purchasing Apps becomes habitual, as Apps facilitate easy way of trading and generate money according to App online stores. Currently, Apps provide label that contains a combination of developer info, memory size, category, operating system compatibility, user ratings and reviews, and privacy policy. However, the product label information is asymmetrical and it varies with the developer. It is challenging to develop common standards explicit to users, as their needs are dynamic; moreover, the App undergoes a series of state changes during execution, according to the usage pattern. We propose a quantification label framework to assess the mobile/web App using a set of quantifiers, such as functionality, degree and domain of connectivity, battery consumption, and its vulnerability index for generating a set of standard labels. The corresponding labels in the label frame are: features, popularity, energy consumption and security. Further, we utilized principal component analysis (PCA), a statistical technique to assist the customers in selecting the prominent features from the dataset and to compare related apps, which analyzes the quantifiers in the given datasets and distinguish them according to the variances. The experimental results in quantifying a real time traffic data of an internet based App validated the proposed label by revealing the key features to the users; moreover, PCA carried out on four sets of traffic data enabled the selection of prominent data, and the results also revealed the possible embedding of the framework within an App for dynamic monitoring.
Investigation of the impact of injection timing and pressure on emissions characteristics and smoke/soot emissions in diesel engine fuelling with soybean fuel
Authors:   Energy and Renewable Energies Technology Center, University of Technology-Iraq, Baghdad, Iraq, Fayad Mohammed A.
Published: May 2021

Engine injection strategy and renewable fuel both can improve nitrogen oxides (NOX) and smoke/soot emissions in a common-rail compression ignition (CI) diesel engine. The effects of different postinjection (PI) timings (15, 30, and 45) after top dead center (aTDC) and injection pressures (550 and 650 bar) on pollutant emissions and smoke/soot emissions were investigated for combustion of a renewable fuel (soybean biodiesel). The results showed that the levels of carbon monoxide (CO), hydrocarbons (HCs), and NOX are reduced from the combustion of soybean biodiesel compared to the diesel fuel combustion for different injection strategy. Besides, NOX emission is clearly reduced with retarded PI timing, especially at 45°. It is found that the increasing injection pressure reduced gaseous emissions for both fuels. The combination between biodiesel fuel and injection strategy can provide meaningful improvements in pollutant emissions, as well as enhance the exhaust temperature compared to the diesel fuel. With biodiesel fueling, smoke/soot emissions were reduced from biodiesel combustion (by 19.7%) under different fuel injection timings and pressures rather than from the diesel fuel combustion (by 12.2%).
Sensorless rotor position estimation of PMSM for low and high rotor speed
Authors:   Electrical Engineering Department, Majmaah University, Almajmaah 11952, Kingdom of Saudi Arabia, Abo-Khalil Ahmed G. ,   Electrical Engineering Department, Assiut University, Assiut, 71515, Egypt
Published: May 2021

In this paper, a sensorless permanent magnet synchronous motor (PMSM) drive was presented based on calculating the back EMF using the reference stator voltages, which are the output of the d-axis current controller, which includes information about the rotor position. Sensorless control estimates the position information necessary for vector control of the motor without using position sensor or encoder. This can provide effects such as increased system reliability and cost and volume reduction. The back EMFs are calculated in a new coordinate based on the estimated speed to minimize the rotor speed estimation error. The estimated rotor position and rotor speed may fail to track the real rotor position and real rotor speed in extremely low speed since the position error can be amplified from the current controller output voltage, and this may cause the instability problems of tracking controller. So, a compensator has been added to the detector to overcome this disadvantage. In order to verify the validity of the proposed sensorless control technique, an experiment was performed on the PMSM, and the results showed fast-dynamic response, low ripples in motor’s currents, and good performance in tracking speed and power references.
Multilevel converter integration for low voltage ride through controlling renewable wind energy conversion systems
Authors:   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Ahmed Mahrous , Alamri Bassem ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Metwally Mohamed ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Alharthi Mosleh ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Alzaed Ali ,   Architectural Eng. Dept., College of Engineering, Taif University, Taif 21944, Saudi Arabia, Elkalashy Nagy ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Salem Farhan ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia, Mekhilef Saad ,   Department of Electrical Engineering, University of Malaya, Kuala Lumpur, Malaysia, Orabi Mohamed ,   APEARC, Faculty of Engineering, Aswan University, 81542, Aswan, Egypt, Ghoneim Sherif ,   Electrical Engineering Department, College of Engineering, Taif University, Taif 21944, Saudi Arabia
Published: May 2021

In this study, a new control of grid-connected doubly-fed induction generators (DFIGs) is introduced to attain lowvoltage ride-through capability. The grid-side converter is proposed to be a multilevel converter (MLC) controlled by conventional DC-link voltage controller. The MLC is designed and integrated into the grid-connected DFIG. The rotor-side converter is considered a two-level conventional converter controlled by the proposed virtual voltage strategy. The virtual strategy is to use the designed input control signal rather than the actual measured one during system disturbance. The system disturbance in this study is the voltage dip. The proposed virtual controller is designed to use busbar voltage during normal operation, whereas it utilizes the designed virtual voltage during wide range conditions of low grid voltages. The energy conversion system currents are increased due to voltage dip disturbances. The use of designed virtual voltage values is proposed as inputs to the controller to limit these currents at the rating values. These virtual voltages are extracted using direct-quadrature machine representation and fixed machine currents at the rated values or lower. On the basis of the proposed control concerning the virtual voltage concept, the generator currents are limited to the rated values, thereby protecting the energy conversion system during low grid voltages. Simulation results prove the validity of the proposed control scheme during extreme low voltages.
Lugar de saída e lugar de chegada: uma análise dos fluxos migratórios em uma comunidade rural no litoral norte do estado da Bahia
Authors: Anunciação Diana
Published: May 2021

The aim of this work is to understand how the rural community Curralinho, located in Mata de São João – North Coast of Bahia, uses migratory movement as a means of social reproduction, identifying the motivations of migrant individuals and the meanings ascribed to this movement for their families and their group. The analysis was based on the influence of State interventions, carried out since 1970, which aimed to promote local economic and touristic development. Methodologically, it was based on qualitative analysis, using oral history, open response interviews and participant observation. It is concluded that the restructuring of migratory flows marked this community as a place of arrival and a place of departure, marking the differences in identity between the “inside” and the “outside”, strengthening the feeling of belonging and impelling structural changes in the socioeconomic and cultural order.
Frente Parlamentar da Agropecuária (FPA): campo de disputa entre ruralistas e petistas no Congresso Nacional brasileiro
Authors: Bruno Regina
Published: May 2021

The purpose of this paper is to ponder over dynamics within the relationships between political opponents in the Brazilian National Congress, specifically when debatingon rural development. I aim to analyse the political dispute between Ruralistas and Petistas in The Parliamentary Agricultural Front (FPA). I intend to display this feud as a broad and complex net of social, political, cultural, and symbolic relationships. Being on the opponent’s ground is part of the dispute.
Regional Analysis of Capital Market in the Czech Republic
Authors: Blažek Jiří
Published: May 2021

The article deals with the issue of interregional differentiation of companies shares quotations on Prague stock exchange which has been up to now neglected. It is argued that data from stock exchange can reveal important features of behaviour of key players (investment funds) on capital market. The results are supporting the argument about emerging regional segmentation of capital market in the Czech Republic.
Environmental History in the United States and Geography
Authors: Jeleček Leoš
Published: May 2021

This article examines the emergence, development, methodology and some results of environmental history as a new historical discipline in the U.S.A. Broader historical, social and ecological connections of this field development and practice are considered. Special attention is focused on some mutual methodological impacts and contributions among environmental history, geography, historical geography and ecology.
LEVEL OF ENERGY SUPPLY OF ANIMAL FARMS FROM USING BIOGAS
Authors: Stadnik Mykola , Shtuts Andrii , Pylypenko Oleksandr
Published: May 2021

Ukraine has untapped potential for the production of own energy from renewable sources - processing of livestock waste (animal manure and bird droppings) with the formation of biogas, which can then be used to produce electricity, heat or fuel - analogues of natural gas (methane) (in particular, for own needs of farms).
Currently in Ukraine, the generation of large amounts of waste on industrial farms is an environmental problem that needs to be addressed. Recycling livestock waste to generate biogas will partially solve environmental problems, as well as benefit from decentralized renewable energy production or fuel production.
The role of renewable energy sources in energy production is constantly growing and now the issue of increasing the share of renewable sources in the energy balance of each country is relevant. In the supply of primary energy, the share of renewable energy accounts for 13% worldwide. Of these, biomass accounts for 10%, or 258 million tons per year, ie in the world biomass provides the largest share of energy supply from renewable sources.
Domestic agricultural enterprises are significant consumers of fuel and energy resources, so they face the objective need to use alternative energy sources, including biofuels and the introduction of innovative energy-saving technologies. Biogas production is an efficient and attractive investment technology, due to the presence of significant raw material potential, favorable climatic and other. However, the level of introduction of this type of energy in the agro-industrial complex is insufficient, which is due to a number of issues, including insufficient level of practical recommendations for choosing power generators, their number, modes of operation taking into account daily energy consumption schedule, load and optimal efficiency. installations while providing autonomous power supply of the enterprise.
This paper determines the level of energy supply of livestock farms through the use of biogas plants as a source of energy used for livestock waste.
1. Ritualized Relief and the Misapplication of Dewey in Service-Learning
Authors: Bailey Megan
Published: May 2021

Abstract: This article investigates the way that service-learning educators make use of John Dewey’s philosophy of education. A hermeneutical analysis of service-learning literature demonstrates that in establishing Dewey as a theoretical framework, service-learning
educators separate learning from service in their thinking, teaching, and writing. Thus, this article considers the effect of distancing learning from service on students’ assumptions of community and the communities served via service-learning. When service-learning educators ignore
the bedrock of their theoretical foundation, service-learning practices have the potential to perpetuate ritualized relief, or a routinization of response to community need that harms communities served and students’ server mindsets.
Yoga Pranayama dan Aromaterapi sebagai Alternatif Penanggulangan Rheumatoid Arthritis pada Lansia
Authors: Maulana Nova
Published: May 2021

Proses menua mengakibatkan perubahan struktur dan fungsi tubuh. Manifestasi klinisnya adalah para lanjut usia akan menngalami nyeri pada lutut dan sendi lain jika berjalan, merupakan kelainan dari rheumatoid arthritis. Nyeri hampir tidak terpisahkan dari rheumatoid arthritis, dimana diketahui penyakit terbanyak yang diderita lansia adalah penyakit sendi (52,3%) dan kasus penderita rheumatoid arthritis di Yogyakarta dan Semarang 5,4%-5,8%, hal ini berarti ketergantungan terhadap obat diusahakan seminimal mungkin. Cara-cara pengobatan non-farmakologi seperti Terapi Yoga “Pranayama” dan Aromatherapy dapat dipakai untuk menurunkan nyeri. Tujuan dari kegiatan ini untuk mengetahui pengaruh Yoga Pranayama terhadap penanggulangan nyeri. Metode kegiatannya yaitu dengan melakukan pelatihan yoga pranayama dengan aromaterapi kepada 20 lansia dipandu oleh instruktur yoga. Pengumpulan data menggunakan kuesioner pretest-posttest tentang keluhan nyeri lansia sebelum dan sesudah dilakukan pelatihan. Hasil kegiatannya ada pengaruh yang signifikan antara sebelum dan setelah dilakukan pelatihan Yoga Pranayama pada kelompok Lansia di Panti ditandai dengan hasil rata – rata penurunan tingkat nyeri sebelum dan  setelah pemeriksaan.
PROPERTIES OF REGULAR FUNCTIONS OF A QUATERNION VARIABLE MODIFIED WITH TRI-COMPLEX QUATERNION
Authors: Kim Ji Eun
Published: May 2021

In a quaternion structure composed of four real dimensions, we derive a form wherein three complex numbers are combined. Thereafter, we examined whether this form includes the algebraic properties of complex numbers and whether transformations were necessary for its application to the system. In addition, we defined a regular function in quaternions, expressed as a combination of complex numbers. Furthermore, we derived the Cauchy-Riemann equation to investigate the properties of the regular function in the quaternions coupled with the complex number.
COVID-19: PSYCHOLOGICAL TIPS FOR ALL
Authors: Naveed Shibli  , Tariq Rashid  , Ali Sher
Published: May 2021

BACKGROUND & OBJECTIVE:  The world is facing a COVID-19 pandemic. The cure for the disease is yet to be established. This situation has created a severe stress-producing challenge for humankind.  It has been reported in few studies that human health and adaptability are dependent on and are related to hope level. How this connection could help humanity to face the COVID-19 challenge was the main focus of the present work.

METHODOLOGY: A library research was conducted to explore the individual potential to increase 'hope’ and to evolve specialized instructions (tips) that could help to improve pandemic stress coping: It was convincing that increase in level of hope with due watchfulness is possible, that could contribute towards improving coping in the prevailing challenging, stressful situation.

RESULTS: To exercise ‘tips’ to improve hope was found psychologically possible. It was also convincing that ‘tips’ by improving the ‘hope’ level would add to the surviving spirit and subsequent coping.

CONCLUSION: Exercising ‘tips’ would improve pandemic stress coping.
STUDENTS PERSPECTIVE ON ONLINE MEDICAL EDUCATION DURNG LOCKDOWN AS A RESULT OF COVID-19 PANDEMIC
Authors: Muhammad Sajid Mehmood  , Wajahat Sultan Baig  , Baig Sadia Azam Khan , Fauzia Khan  , Shakil Ahmad Awan  , Ayesha Babar
Published: May 2021

ABSTRACT:

Objective: In this study the perceptive of undergraduate medical students regarding e-learning were explored in the MBBS students across various medical colleges in Pakistan during COVID pandemic.

Study type, settings and duration: It was descriptive study conducted as multisite survey in medical students of Pakistan. The study was conducted from 1st October to 30th October 2020.

Methodology: A questionnaire was developed and disseminated via what’s app to MBBS students of medical institutes in Pakistan. The data was cleaned and study sample was selected from ten medical colleges with maximum response rates. The responses of 10 students from each professional year were selected randomly for even distribution of students in the MBBS course. Out of 500 students, 492 students’ replied with valid data. The percentages of the responses were calculated and data was analyzed graphically.

Results: The mean age of respondents was 22± 2.1. 64.4% of respondents were female and 43.6% male. Only 5 % of total students were of the opinion that online teaching was good substitute for learning than face to face sessions. 43% students responded that ZOOM software was major platform used for e-learning during lockdown. Internet connectivity was the major hurdle in e-learning and health issues in family (27%) was major stress factor. 31% students responded that online classes were not effective and 29 % responded that they were about 25 % effective while 21% were of the opinion that these were 50% effective as compared to face to face campus learning.

Conclusion: The perception of medical students regarding online teaching was not promising in our study. Most of the indicators were negative.
Derivations on the module extension Banach algebras
Authors: Bodaghi A. , Teymouri A. , Ebrahimi Bagha D.
Published: May 2021

UDC 517.986
We correct some results presented in [M. Eshaghi Gordji, F. Habibian, A. Rejali,  Ideal amenability of module extension Banach algebras, Int. J. Contemp. Math. Sci.,  2, No. 5, 213–219 (2007)] and, using the obtained consequences, we find necessary and sufficient conditions for the module extension to be -weakly amenable, where is a closed ideal of the Banach algebra and is a closed -submodule of the Banach -bimodule We apply this result to the module extension where are two Banach -bimodules.
Про взаємозв'язок точних констант в нерівностях типу Колмогорова і Колмогорова-Ремеза.
Authors: Kofanov V. A.
Published: May 2021

УДК 517.5
Доведено теорему про взаємозв'язок точних констант у нерівностях типу Колмогороваі Колмогорова–Ремеза для диференційовних періодичних функцій. Як наслідок встановлено новi точнi нерiвностi типу Колмогорова–Ремеза на класах таких функцій. Крім того, отримано новi точнi нерiвностi типу Бернштейна–Ремеза для тригонометричних поліномів і поліноміальних сплайнів.
Characterizations of additive -Lie derivations on unital algebras
Authors: Ashraf M. , Jabeen A.
Published: May 2021

UDC 512.5
Let be a commutative ring with unity and be a unital algebra over (or field ).An -linear map is called a Lie derivation on if holds for all For scalar an additive map is called an additive -Lie derivation on if where holds for all In the present paper, under certain assumptions on it is shown that every Lie derivation (resp., additive -Lie derivation) on is of standard form, i.e., where is an additive derivation on and is a mapping vanishing at with in Moreover, we also characterize the additive -Lie derivation for by its action at zero product in a unital algebra over
Aspects of Atlas Mapping for Analysis of Energy Infrastructure in Different Regions
Authors: Trofimov I. , Trofimov L.
Published: May 2021

he paper addresses the visualization and systematization of cartographic material for analyzing energy infrastructure in various world regions. It discusses the technology (architecture) for building maps based on the concept of atlas mapping. An interface was developed for the construction of interactive maps and navigation in any section of the world atlas - from the level of world continents to a detailed map of any region within the country. We have constructed and stored contour maps of all countries of the world in the database of the computing geo-information system (СGIS). CGIS allows constructing hybrid maps, which contain vector and raster map layers with the energy infrastructure overlaid on them in the selected territory. An algorithm was constructed to search for energy objects and administrative entities in any country or region of the world. The atlases built by CGIS are used at Melentiev Energy Systems Institute (MESI) of the Siberian Branch of the Russian Academy of Sciences to plot the solutions obtained with the optimization model ORIRES (which reflects the optimal operation of the interconnected power systems in different scenarios) on a map of a selected area or region.
TREATMENT OF VENOUS INSUFFICIENCY EMERGING AFTER COVID-19 DISEASE
Authors: EKİM Meral , EKİM Hasan
Published: May 2021

COVID-19 disease caused by the virus called severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious disease leading to hyperinflammation. Lockdown measures implemented due to COVID-19 can lead to weakness in the calf muscles of the elderly individuals who stay at home for a long time and in those receiving COVID-19 treatment in intensive care unit. Thus, venous insufficiency may develop in these circumstances. It is important to treat these patients without delay, as it may prevent the progression to chronic venous insufficiency. Our study includes eight patients who were diagnosed with COVID-19 and were discharged after being treated in various centers, but later developed venous insufficiency. Two of the patients were women and six were men. Their ages ranged from 43 to 70, and the mean age was 56.87 ± 9.70 years. The main complaints of the patients were pain, swelling, itching, tingling, burning, edema, cramping, feeling of heaviness and discoloration in the legs. All patients were hypertensive and five patients were using tobacco products. In addition, two patients had diabetes and one patient had concomitant coronary artery disease. All patients had weak calf muscles and high D-dimer levels. Venous insufficiency was diagnosed because reflux was detected in the deep veins of both lower extremities in the color venous Doppler ultrasonographic examination of the patients. Considering that venous insufficiency may be seen after recovery in COVID-19 patients, intermittent control of these patients should be done after discharge. It is important to closely monitor patients who develop venous insufficiency after COVID-19 treatment, and to strengthen the weakened calf muscles with exercises in addition to medical treatment with venoactive drugs. Since venous insufficiency may regress as a result of the strengthening of calf muscles, it should not be rushed for invasive procedures.
Les décors d’Intolérance
Authors: Berthomé Jean-Pierre
Published: May 2021

À partir de l’historique de la production du film de Griffith, cet article met en perspective la prise en considération de ses décors dans les années 1970 à travers, en particulier, les souvenirs publiés alors par divers participants à l’entreprise et les premiers essais critiques sur le sujet. Il développe ensuite une analyse des divers décors d’Intolérance et détaille leurs sources d’inspiration. Il développe encore une réflexion nouvelle sur le recours qui y est fait aux effets spéciaux et propose l’hypothèse que l’enjeu des décors n’est pas leur exactitude historique mais leur démesure spectaculaire. S’attachant pour finir au décor emblématique du grand parvis de Babylone, il montre que les stratégies mises en œuvre y sont empruntées, comme ailleurs dans le film, aux usages de la scène théâtrale du début du siècle.
Agnaldo Manoel dos Santos ou la subversion de la modernité consentie
Authors: Bevilacqua Juliana Ribeiro da Silva
Published: May 2021

Cet article examine comment les critiques, les conservateurs et les artistes élaborèrent un récit biaisé de la vie et de l’œuvre du sculpteur bahianais Agnaldo Manoel dos Santos (1926-1962) réduisant leur interprétation à un lien inconscient et atavique avec le continent africain. À la lumière de ce que j’appellerai ici une « modernité consentie », il est possible de montrer comment cet artiste noir, qui ne reçut pas d’éducation académique, subvertit le monde des arts en occupant une place qui ne lui était pas réservée.
A Mão do Povo : Appropriations du populaire dans l’art des femmes brésiliennes des années 1970
Authors: Sneed Gillian
Published: May 2021

Cet article examine les œuvres d’art des années 1970 de Regina Vater, Lygia Pape et Anna Bella Geiger, qui ont adopté des formes culturelles « populaires », notamment l’art populaire, l’artisanat et les rituels et coutumes autochtones et afro-brésiliens. Comment ces femmes blanches, urbaines et issues de la classe moyenne ont-elles déployé des références au populaire et au « féminin » dans leurs œuvres de manière ambivalente et comment ont-elles renégocié les frontières complexes entre le primitivisme, l’appropriation culturelle et l’anthropophagie, termes que cet essai déploie en s’appuyant sur les théorisations de la race et de l’identité formulées par Denise Ferreira da Silva et Suely Rolnik.
Du miracle au miraculeux : une déconstruction derridienne du miracle
Authors: de Rochechouart Alice
Published: May 2021

Bien que le motif du miracle n’apparaisse que très rarement dans la philosophie derridienne, il est possible d’en proposer une caractérisation, évidemment bien éloignée de sa traditionnelle acception théologique. Ainsi, sous la plume de Derrida, le miracle devient la structure même de la croyance, impliquée dans toute adresse à autrui. Cette reconfiguration de la notion de croyance conduit alors à penser le miracle comme la foi nue, c’est-à-dire comme l’irréductibilité du religieux. De ce fait, le miracle n’est plus conçu comme ce qui déroge à la probabilité naturaliste : à l’inverse, la structure du miraculeux devient l’un des noms de l’éthique de l’impossible, sous les traits d’une structure aporétique de l’événementialité.
Management of a ruptured and unruptured pial arteriovenous fistula during and after pregnancy
Authors: Gerndt Clayton H. , Goodrich Dylan J. , Ramanathan Dinesh , Dahlin Brian C. , Waldau Ben
Published: May 2021

We present the case of a 16-week pregnant 19-year-old female who presented with hemiplegia due to a ruptured right frontal pial arteriovenous fistula (PAVF). She was also found to have an unruptured right temporal PAVF and a family history of brain hemorrhage. The patient was managed with Onyx embolization of the ruptured fistula, followed by surgical excision and hematoma evacuation. At 35 weeks gestation, she underwent cesarean section to prevent rupture of the second fistula in the setting of peripartum hypervolemia and increasing headaches. The child was delivered healthy. Subsequently, the right temporal AV fistula, supplied by a middle cerebral artery and posterior cerebral artery branch, underwent staged embolization resulting in complete occlusion. The patient recovered to a modified Rankin score of two, with a left foot drop as only persistent significant motor deficit.
Dual-center study comparing transradial and transfemoral approaches for flow diversion treatment of intracranial aneurysms
Authors: Khandelwal Priyank , Majmundar Neil , Rodriguez Gustavo J. , Patel Pratit , Dodson Vincent , Singla Amit , Khatri Rakesh , Gupta Vikas , Sheriff Faheem , Vellipuram Anantha , Cruz-Flores Salvador , Maud Alberto
Published: May 2021

BACKGROUND:

The transfemoral approach (TFA) has been the traditional approach for neurointerventional cases. While the TFA allows for triaxial support in flow diverting stent cases, it is associated with access site complications. Recently, the transradial approach (TRA) has emerged as a safer alternative to the TFA. To the best of our knowledge, there have only been single-center studies comparing outcomes in flow diverter cases for these approaches. We demonstrate the safety and feasibility of the TRA for placement of flow diverting stents in the treatment of unruptured intracranial aneurysms at two high-volume centers.

MATERIALS AND METHODS:

We performed a retrospective review of prospectively collected institutional databases at two high-volume neuroendovascular centers. Cases from 2016 to 2018 of unruptured intracranial aneurysms treated by flow diverting stenting accessed through either the TRA or the TFA were compared. Patient demographics, procedural and radiographic metrics including location and size of the aneurysm, size, and length of the flow diverter implant, and fluoroscopic time were recorded. Puncture site complications and length of hospital stay were also included in the data analysis.

RESULTS:

There were three out of 29 TRA cases which were converted to the TFA. None of the TRA patients experienced site complications, whereas three TFA patients experienced site complications. While TRA and TFA patients did not differ significantly in their exposure to radiation, TRA patients experienced shorter hospital stays.

CONCLUSIONS:

While long-term studies are still lacking regarding this approach, we demonstrate that the TRA is a safe and feasible approach for flow diverter stent placement.
Pipeline embolization of ruptured, previously coiled cerebral aneurysms
Authors: Cooper Jared B. , Li Boyi , Kaur Gurmeen , Gandhi Chirag D. , Santarelli Justin G.
Published: May 2021

PURPOSE:

Aneurysmal recurrence represents a significant drawback of endovascular coiling, particularly in aneurysms that have previously ruptured. Given the high recurrence rate of coiled aneurysms and particularly the risk of posttreatment rupture in previously ruptured aneurysms that have been treated by coiling, the question of how best to treat ruptured aneurysms that recur postcoiling remains.

MATERIALS AND METHODS:

We conducted a retrospective analysis of twenty patients who underwent pipeline embolization of previously ruptured, coiled cerebral aneurysms.

RESULTS:

Pipeline embolization device (PED) treatment resulted in complete aneurysmal occlusion in 10 patients (62.5%) at first angiographic follow-up, and 11 patients (68.75%) at last follow-up. No PED-related complications were encountered and there were no peri-procedural or postprocedural hemorrhages, or symptomatic ischemic events following flow diversion.

CONCLUSIONS:

PED as a second-line treatment is a safe and effective modality for achieving aneurysmal occlusion in recurrent, previously ruptured, primarily coiled aneurysms. Additionally, a staged coil-to-PED approach may be considered for the management of acutely ruptured aneurysms to achieve aneurysmal obliteration in an effort to mitigate recurrence, and reduce the amount of postprocedural studies.
Shared Decision-Making, Advance Care Planning for Chronic Kidney Disease Patients
Authors: Deodhar Jayita , Nagaraju Shankar Prasad , Kirpalani Ashok L. , Nayak Ajith M
Published: May 2021

Advance care planning (ACP) is a process by which clinicians together with patients and families reflect on and outline care goals to inform current and future care. ACP or shared decision-making is not only about key medical decisions, such as decision about continuing dialysis, or agreement for “not for resuscitation” order when in hospital. The importance of its role in chronic kidney disease (CKD) patients is less known and not being well practiced in our country. When done well, it involves enhancement of final days, weeks, and months with positive decisions about family relationships, resolution of conflict, and living well until end of life, improved quality of life, decreased anxiety and depression among family members, reduced hospitalizations, increased uptake of hospice and palliative care services, and care that concurs with patient preferences. It lays out a set of relationships, values, and processes for approaching end-of-life decisions for the patient. It also includes attention to ethical, psychosocial, and spiritual issues relating to starting, continuing, withholding, and stopping dialysis. This workshop was done to sensitize ACP as a standard of care intervention in the management of CKD in our country.