bluuebunny/crossref_metadata_2025 huggingface dataset:
Whither Bir Zeit University?
Authors: Sabella Anton
Published: February 2021

Since its founding under the Israeli occupation, Bir Zeit University has been the catalyst for educating the Palestinian ‘generations of occupation'. Its mission was to empower those who were bereft of their basic human rights and to reclaim and develop the Palestinian national identity by resisting the stultification of Palestinian youth. Following the Oslo Accords, Bir Zeit University has experienced several important developments, namely exponential growth in enrolment, unnecessary programmatic expansion, introduction of super-size classes, and irresponsible staffing decisions. Against this background and a growing financial crisis, this case study examined how managerialism has succeeded in subduing Bir Zeit University to its syllabus, specifically how cultural and structural changes have led to compromising the work conditions and relationships of faculty members. Hence, this case study bids the question—Whither Bir Zeit University?—to those who care to question the present state of affairs as well as anyone ready to search for answers.
Bipolar Tension and Employee Relations Challenge at a Higher Education Institution
Authors: Eid Niveen Labib , Dahadha Mays
Published: February 2021

This is a case of employee relations challenge at ASE, a Palestinian higher education institution (HEI). It reflects on real narratives and experiences of an accumulative and an endured conflict between ASE's labor union and its top management due to rigid administrative policies and pitfalls while transitioning through a strategic reform. The case urges readers to revert to the roots, envisage, and analyze 'internal employee relations under crises' from a dialogical and a sociopolitical perspective based on ideas drawn from the Habermas's 'Theory of Communicative Action' (TCA). HEIs are envisaged as sovereign workplaces that function on pluralistic values generating positive dialogue communication between all stakeholders and subsequently healthy employee relations. This case examines different episodes where ASE's management utilized autocratic leadership for utilitarian drivers causing employee exclusion and mounting tensions on campus. Consequently, several forms of overt resistance prevailed including strikes, apathy, and work interruptions.
Assessing the Existing Vegetation Around Abandoned Mining Areas With Potentially Toxic Heavy Metals
Authors: Naranjo Gómez José Manuel , Cabezas Fernández José , Castanho Rui Alexandre , Pinto Gomes Carlos José
Published: February 2021

In abandoned mining areas, heavy metals may exist. Those heavy metals can cause physical consequences and death. Through the use of geographic information systems (GIS), the environmental diagnosis of vegetation potentially affected by the presence of very toxic heavy metals in abandoned mining areas in Extremadura was conducted. Initially, graphic and alphanumeric information was obtained from numerous sources, and the geospatial database generated was analyzed, allowing the location of abandoned mines. Subsequently, the mines were classified according to the degree of toxicity of the heavy metals that had been exploited. Then, taking into account the mines whose heavy metals were considered very toxic, a geospatial analysis was performed using concentric buffers at 1, 5, 10, 20, 40, and 60 kilometres. The results obtained made it possible to obtain thematic cartography representative of the areas potentially affected. The proportion of vegetation potentially affected, has been classified according to the existing vegetation series and climatic belts.
Governance, Planning, and Territorial Management
Authors: Jurado Almonte José Manuel , Pazos-García Francisco José , Felicidades García Jesús
Published: February 2021

In the European Union, there have been significant developments in recent decades in cross-border cooperation and the removal of borders. Thirty years have passed since the launch of the Interreg funds, which finance territorial cooperation policies between Spain and Portugal. Despite these developments, which have encouraged economic and social flows between the two states, the border effect persists in many aspects, especially in terms of governance and shared territorial management. This study, therefore, focuses on how to address the border issue in the different spatial, sectoral, and urban planning instruments. This has involved analysing the different governance, planning, and territorial management systems in Spain and Portugal using the cross-border area of the Baixo Guadiana as a case study. As a preview of the results, following a comparative diagnosis, a number of obstacles and differences in spatial planning, and other territorial actions in this area have been revealed that are a hindrance to the integrated planning and co-management of the Spanish-Portuguese border area.
The Use of Quantitative Methods in Investment Decisions
Authors: Eti Serkan
Published: February 2021

Quantitative methods are mainly preferred in the literature. The main purpose of this chapter is to evaluate the usage of quantitative methods in the subject of the investment decision. Within this framework, the studies related to the investment decision in which quantitative methods are taken into consideration. As for the quantitative methods, probit, logit, decision tree algorithms, artificial neural networks methods, Monte Carlo simulation, and MARS approaches are taken into consideration. The findings show that MARS methodology provides a more accurate results in comparison with other techniques. In addition to this situation, it is also concluded that probit and logit methodologies were less preferred in comparison with decision tree algorithms, artificial neural networks methods, and Monte Carlo simulation analysis, especially in the last studies. Therefore, it is recommended that a new evaluation for investment analysis can be performed with MARS method because it is understood that this approach provides better results.
Global Trends in Domestic savings and Longevity- Implications for India
Authors: Venkatesan Thilak , Venkataraman R
Published: February 2021

Demographic dividend and the lowest median age among the earning population propels consumption and growth in India. Among the emerging economies, China had the leverage for growth through exports until 2008. India benefited by demographic dividend and this translates to providing income and thereby increases savings. On the other hand, the developed countries are experiencing problems of an aging economy, a deflationary scenario, and a pension burden. India, with its major workforce in the unorganized and private sector, needs to recognize the need for forward-looking policies that stimulate savings for a better lifestyle post-retirement. The study was focussed on the relationship between longevity (life expectancy), and domestic savings. The research observed divergence between the developed nations and India. A more futuristic policy action is suggested to motivate savings as the increase in population and higher levels of economic growth can be achieved with more domestic savings.
The Effect of e-Finance Service Quality on Bank Customers' Fintech e-Loyalty
Authors: Jerene Wondwossen , Sharma Dhiraj
Published: February 2021

The expansion of information communication technology (ICT) significantly influences organizations service delivering culture. The financial institutions, particularly the banking industry are one of the major sectors that invests large amount of capital for introducing new technologies. E-finance is one of the technology channels that bankers introduced to their customers to access financial services. Therefore, this study was aimed to study the effect of e-finance service quality on bank customers' fintech loyalty of using the e-finance services in future. Primary data was collected from 412 bank customers and it was analyzed using the structural equation model (SEM) through AMOS. The result revealed that both in normal operations of e-finance service and recovery services, the quality of service positively influences bank customers' satisfaction and their e-loyalty.
Financial Literacy
Authors: Valencia Álvarez Adriana Berenice , Valenzuela González Jaime Ricardo
Published: February 2021

Financial literacy is a combination of financial knowledge, attitudes and behaviors, key for making informed decisions and for solving financial problems. This descriptive study explored the applied, conceptual and procedural financial knowledge of 243 Mexican students via three financial knowledge tests. In addition, these students were surveyed about their financial behavior, their attitudes towards money, and their experience with money using a self-report questionnaire. The study aims to identify financial-education needs and gaps between school levels and systems. Therefore, the analysis focuses on the differences and similarities between two subgroups: (1) students in public and in private education, and between (2) middle school (ages 12 to 15) and high school students (ages 15 to 18). Middle school and high school students differed significantly only in their conceptual knowledge and in their financial experience, while public and private students showed statistical significant differences on their financial knowledge, behavior, attitudes and experience.
Measuring Financial Literacy of the Housewife to Generate Marketing Strategies
Authors: Eti Serkan , Temizel Ece Nur
Published: February 2021

This chapter evaluates the financial literacy of the housewife by analyzing a survey of a minimum of 204 housewives in Turkey. Findings from the 25 questions of the survey show housewives in Turkey generally have Turkish Lira deposits but also have a low tendency to spend. It was found that the financial literacy of housewives was low. In this context, it will be appropriate to increase this literacy through general education. In this way, housewives will be able to better evaluate their savings and the financial system of the country will work more effectively.
Traffic Congestion Reduction and Accident Circumvention System via Incorporation of CAV and VANET
Authors: Khan Mohsin , Arora Bhavna
Published: February 2021

Connected automated vehicle (CAV) technology is the core for the new age vehicles in research phase to communicate with one another and assimilation of vehicular ad-hoc network (VANET) for the transference of data between vehicles at a quantified place and time. This manuscript is an enactment of the algorithms associated to the maintenance of secure distance amongst vehicles, lane shifting, and overtaking, which will diminish the occurrence of collisions and congestions especially phantom jams. Those implementations are centered over CAV and VANET technology for the interconnection of the vehicles and the data transmission. The data is associated to the aspects of a vehicle such as speed, position, acceleration, and acknowledgements, which acts as the fundamentals for the computation of variables. In accordance with the environment of a particular vehicle (i.e., its surrounding vehicles), real-time decisions are taken based on the real-time computation of the variables in a discrete system.
Artificially Intelligent Physiotherapy
Authors: Godse Sachin Pandurang , Singh Shalini , Khule Sonal , Wakhare Shubham Chandrakant , Yadav Vedant
Published: February 2021

Physiotherapy is the trending medication for curing bone-related injuries and pain. In many cases, due to sudden jerks or accidents, the patient might suffer from severe pain. Therefore, it is the miracle medication for curing patients. The aim here is to build a framework using artificial intelligence and machine learning for providing patients with a digitalized system for physiotherapy. Even though various computer-aided assessment of physiotherapy rehabilitation exist, recent approaches for computer-aided monitoring and performance lack versatility and robustness. In the authors' approach is to come up with proposition of an application which will record patient physiotherapy exercises and also provide personalized advice based on user performance for refinement of therapy. By using OpenPose Library, the system will detect angle between the joints, and depending upon the range of motion, it will guide patients in accomplishing physiotherapy at home. It will also suggest to patients different physio-exercises. With the help of OpenPose, it is possible to render patient images or real-time video.
Characterization and Predictive Analysis of Volatile Financial Markets Using Detrended Fluctuation Analysis, Wavelet Decomposition, and Machine Learning
Authors: Sanyal Manas K. , Ghosh Indranil , Jana R. K.
Published: February 2021

This paper proposes a granular framework for examining the dynamics of stock indexes that exhibit nonparametric and highly volatile behavior, and subsequently carries out the predictive analytics task by integrating detrended fluctuation analysis (DFA), maximal overlap discrete wavelet transformation (MODWT), and machine learning algorithms. DFA test ascertains the key temporal characteristics of the daily closing prices. MODWT decomposes the time series into granular components. Four pattern recognition algorithms—adaptive neuro fuzzy inference system (ANFIS), dynamic evolving neural-fuzzy inference system (DENFIS), bagging and deep belief network (DBN)—are then used on the decomposed components to obtain granular level forecasts. The entire exercise is performed on daily closing prices of Dow Jones Industrial Average (DJIA), National Stock Exchange of India (NIFTY), Karachi Stock Exchange (KSE), Taiwan Stock Exchange (TWSE), Financial Times Stock Exchange (FTSE), and German Stock Exchange (DAX). MODWT-Bagging and MODWT-DBN appear as superior forecasting models.
View Materialization Over Big Data
Authors: Kumar Akshay , Kumar T. V. Vijay
Published: February 2021

Advances in technology have resulted in the generation of a large volume of heterogeneous big data for large enterprises engaged in e-commerce, healthcare, education, etc. This is being created at a rapid rate but is low in its veracity. This big data includes large sets of semi-structured and unstructured data and is stored over a distributed file system (DFS). This data can be processed in a fault tolerant manner using several frameworks, tools, and advanced database technologies. Big data can provide important information, which can be used for business decision making. View materialization, which has been widely studied for structured databases or data warehouse, has been extended to big data to enhance efficiency of big data query processing. This paper focuses on the selection of big data views for materialization. The big data views can be identified by extracting a set of query attributes from the set of query workload of an enterprise. The query attributes are interrelated resulting in the creation of alternate access paths for query evaluation. The cost of query processing using big data views involves the integrity of different data types of heterogeneous big data, frequency of queries, change in the size of big data, selected sets of big data materialized views, and updates on big data and these sets of materialized views. The cost of query processing is computed using the stored size of big data views on the DFS system, which is a consistent processing framework of DFS. A big data view selection algorithm that is capable of selecting views from structured, semi-structured, and unstructured data has been proposed in this paper. The proposed algorithm would select big data views that would result in faster processing of most user queries resulting in efficient decision making.
OCL Constraints Checking on NoSQL Systems Through an MDA-Based Approach
Authors: Abdelhedi Fatma , Brahim Amal Ait , Zurfluh Gilles
Published: February 2021

Big data have received a great deal of attention in recent years. Not only is the amount of data on a completely different level than before, but also the authors have different type of data including factors such as format, structure, and sources. This has definitely changed the tools one needs to handle big data, giving rise to NoSQL systems. While NoSQL systems have proven their efficiency to handle big data, it's still an unsolved problem how the automatic storage of big data in NoSQL systems could be done. This paper proposes an automatic approach for implementing UML conceptual models in NoSQL systems, including the mapping of the associated OCL constraints to the code required for checking them. In order to demonstrate the practical applicability of the work, this paper has realized it in a tool supporting four fundamental OCL expressions: iterate-based expressions, OCL predefined operations, If expression, and Let expression.
Image Retrieval Using Intensity Gradients and Texture Chromatic Pattern
Authors: Jacob I.Jeena , Paulraj Betty , Darney P. Ebby , Long Hoang Viet , Tuan Tran Manh , Yesudhas Harold Robinson , Shanmuganathan Vimal , Eanoch Golden Julie
Published: February 2021

Methods to retrieve images involve retrieving images from the database by using features of it. They are colour, shape, and texture. These features are used to find the similarity for the query image with that of images in the database. The images are sorted in the order with this similarity. The article uses intra- and inter-texture chrominance and its intensity. Here inter-chromatic texture feature is extracted by LOCTP (local oppugnant colored texture pattern). Local binary pattern (LBP) gives the intra-texture information. Histogram of oriented gradient (HoG) is used to get the shape information from the satellite images. The performance analysis is land-cover remote sensing database, NWPU-VHR-10 dataset, and satellite optical land cover database gives better results than the previous works.
Complex Events Processing on Live News Events Using Apache Kafka and Clustering Techniques
Authors: Lakkad Aditya Kamleshbhai , Bhadaniya Rushit Dharmendrabhai , Shah Vraj Nareshkumar , Lavanya K. (cb1dcf24-9f08-4fc8-b04b-47bbc153bc8e
Published: February 2021

The explosive growth of news and news content generated worldwide, coupled with the expansion through online media and rapid access to data, has made trouble and screening of news tedious. An expanding need for a model that can reprocess, break down, and order main content to extract interpretable information, explicitly recognizing subjects and content-driven groupings of articles. This paper proposed automated analyzing heterogeneous news through complex event processing (CEP) and machine learning (ML) algorithms. Initially, news content streamed using Apache Kafka, stored in Apache Druid, and further processed by a blend of natural language processing (NLP) and unsupervised machine learning (ML) techniques.
Programmable Implementation and Blockchain Security Scheme Based on Edge Computing Firework Model
Authors: Qin Bao Yi , Hao Zheng , Qiang Zhao
Published: February 2021

In cloud computing, since the program runs in cloud, it can be written in programming language and maintained only in the cloud after compilation. Due to the heterogeneous nature of the edge node platform, many tasks are migrated from the cloud to the edge terminal. It is not easy to realize the programming under the edge computing, and the maintenance cost is also high. At the same time, because the programmable is a high-risk activity, it has high security requirements. In order to solve this problem, this paper designs a programmable and blockchain security scheme based on the edge computing firework model, realizes the programming of the internet of things (IoT) gateway firework node under the edge computing, and appreciates the safe transmission and storage of programmable data through the blockchain system. The experimental results show that this scheme not only facilitates the user's programming, enhances the real-time performance, and saves the data transmission cost, but also ensures the security and reliability of the system.
A New Pedestrian Feature Description Method Named Neighborhood Descriptor of Oriented Gradients
Authors: Liu Qian , Yang Feng , Tang XiaoFen
Published: February 2021

In view of the issue of the mechanism for enhancing the neighbourhood relationship of blocks of HOG, this paper proposes neighborhood descriptor of oriented gradients (NDOG), an improved feature descriptor based on HOG, for pedestrian detection. To obtain the NDOG feature vector, the algorithm calculates the local weight vector of the HOG feature descriptor, while integrating spatial correlation among blocks, concatenates this weight vector to the tail of the HOG feature descriptor, and uses the gradient norm to normalize this new feature vector. With the proposed NDOG feature vector along with a linear SVM classifier, this paper develops a complete pedestrian detection approach. Experimental results for the INRIA, Caltech-USA, and ETH pedestrian datasets show that the approach achieves a lower miss rate and a higher average precision compared with HOG and other advanced methods for pedestrian detection especially in the case of insufficient training samples.
Eyeblink Robot Control Using Brain-Computer Interface for Healthcare Applications
Authors: Ramakuri Sravanth K. , Chithaluru Premkumar , Kumar Sunil
Published: February 2021

The human brain is the central organ of the human system. Many people in the world cannot move on their own and can't control things on their own. A person whose brain is active can control things using the neuro-controlled robot car. It is interesting to all types of people to measure their concentration and piece level of mind with the neuro sky mind wave device. One can easily control the robot's movements by simply blinking eyes; the robot's speed will be according to the subject's attention levels. The neuro sky mind wave device digitizes brain wave signals to power the user-interface of the computers, game, and health application. The neuro sky mind wave device will measure brain waves from the forehead. The paper aims to control a robot using the brain-computer interface concept without any muscular activity controlling healthcare applications directions. The brain activity is recorded with the neuro sky mind wave device's help, and the attention values are sent to the Arduino with the help of the HC-05 Bluetooth module. Arduino is programmed so that if the attention values between 0-29 and the person are relaxed, the green light will glow for the feedback.
QSAR Study of α-Glucosidase Inhibitors for Benzimidazole Bearing Bis-Schiff Bases Using CoMFA, CoMSIA, and Molecular Docking
Authors: Khaldan Ayoub , Bouamrane Soukaina , El-Mernissi Reda , El Khatabi Khalil , Aanouz Ilham , Aggoram Abderrahmane , Sbai Abdelouahid , Bouachrine Mohammed , Lakhlifi Tahar
Published: February 2021

A new class of benzimidazoles bearing bis-Schiff bases as α-glucosidase inhibitory was studied based on the combination of two computational techniques such as 3D-QSAR and molecular docking. The CoMFA and CoMSIA QSAR models were developed from fifteen compounds in the training set and four compounds in the test set giving Q2 values of 0.587 and 0.597 respectively, and R2 values of 0.970 and 0.990 respectively. The adapted alignment method with the suitable parameters resulted in reliable models. The CoMFA and CoMSIA contour maps allowed the authors to recognize regions where the activity can be increased or decreased by suitable substitutions. According to these contour maps they have proposed three new compounds with high predicted activities. Moreover, to confirm the stability of these newly designed molecules in the receptor with PDB: 3A4A, a Surflex-docking was applied.
In silico Predictive Phytotoxicity Modeling of lactuca sativa of Personal Care Product Ingredients
Authors: Vishvkarma Aadarsh , Banjare Purusottam , Singh Jagadish , Roy Partha Pratim
Published: February 2021

Detection and evaluation of environmental toxicity of emerging contaminants like personal care product (PCP) additives are the thrust area in the recent day risk assessment of chemical hazards. The phytotoxicity assay is usually performed to identify and quantify the environmental impact of pollutants. In this background, the authors have developed in silico predictive phytotoxicity models for 36 PCP ingredients using 2D molecular descriptors using multiple linear regression as a chemometric tool. The statistical validation parameters assured the robustness of the developed models according to OECD guidelines. The mechanistic output of the models indicated the importance of the partition coefficient (CrippenLogP) and molecular hydrophilicity. The applicability domain explicitly defines the reliability of the application of the developed models for the unknown PCP ingredients in a consensus manner. The first reported predictive phytotoxicity models for PCP ingredients can help depict the environmental impacts of these classes of emerging pollutants.
Six-Assurance Case Patterns by Strengthening/Weakening Argument
Authors: Koshiyama Tsutomu , Takahashi Sei
Published: February 2021

Goal structuring notation (GSN) is widely used in safety cases and other methods for assuring reliability. Demonstrating the fulfillment of a claim in the GSN requires that its achievement be interpreted logically and structurally by the reader. This study proposes a typical pattern of interpreting these structural interpretations. Furthermore, the proposed patterns were verified for their application to actual GSN samples, and the applicability of these patterns was validated. In addition, these patterns were compared with the existing use of the so-called multi-legged arguments, and the differences between them were shown. Moreover, some of the proposed patterns show that there is a difference in the degree of certainty in the achievement of the converted claim, which indicates achievement of the claim from which it is derived.
Optimization Trends for Wireless Network On-Chip
Authors: Lakhdari Saliha , Fateh Boutekkouk
Published: February 2021

Designing sustainable and high-performance wireless multi-core chips requires a matchless tradeoff between many aspects including scalable and reliable architectures implementation which in its turn implies aware-wideband energy-efficient wireless interfaces and adopting innovative straightforward optimization approaches to achieve the optimal configuration with a minimal cost. This paper focuses on investigating various existing designs and methodologies for wireless network on chip (WiNoC) architectures, as well as the different emerging technologies and optimization tools for the design of a robust and reliable WiNoC infrastructure with a special focus on combinatorial optimization meta-heuristics.
EXPANSÃO DA CADEIA DA SOJA NA AMAZÔNIA SETENTRIONAL: OS CASOS DE RORAIMA E AMAPÁ
Authors: De Lima Maria do Socorro Bezerra
Published: February 2021

A expansão do cultivo da soja em direção à Amazônia alcançou destaque na última década. Estimulada pela demanda internacional do mercado, esta cultura tornou-se um elemento-chave na estratégia brasileira de geração de superávit, bem como das estratégias de localização das corporações agroalimentares dada à importância da produção de soja no Brasil e no Cone Sul. A expansão do cultivo na Amazônia gerou um novo desenho com a criação de novos espaços produtivos, com a criação de novas rotas de logística e de transporte. Nesse novo desenho, esta dinâmica alterou o arranjo territorial e produtivo da economia regional imprimindo uma nova lógica na gestão do território, conduzida em parte pelas grandes corporações. Este artigo visa contribuir com a discussão sobre as dinâmicas e os processos de expansão do cultivo da soja nas denominadas “últimas fronteiras agrícolas” do país. O estudo considera como casos empíricos a expansão da soja nos estados de Roraima e Amapá, localizados na Amazônia setentrional brasileira. A pesquisa de caráter qualitativo consiste no mapeamento dos atores sociais e suas redes de políticas. Também se empregam dados da pesquisa de Produção Agrícola Municipal (PAM), do Instituto Brasileiro de Geografia e Estatística (IBGE), para os municípios selecionados no período de 2010-2016. Os resultados evidenciam que a dinâmica de expansão da fronteira agrícola setentrional é mobilizada tanto pelo corredor logístico do Arco Norte (Eixos Central e Oeste) como pelas estratégias espaciais das grandes corporações do setor agroalimentar e de grupos a ela vinculados. Os cultivos se expandem sob trechos do centro-norte roraimense e sul amapaense, sobretudo nas áreas dos lavrados/cerrados, mas as áreas de florestas também vêm sendo utilizadas. Esse cenário resulta numa maior reestruturação produtiva e seletiva desses territórios, acompanhada de uma geração de renda cada vez mais concentrada, o que, não raro, origina passivos sociais e ambientais crescentes.
Friction Coefficient and Wear of PEEK-PTFE Hybrid Radial Ball Bearings under Dry Conditions
Authors: Hiraki Kazutoshi , Mizobe Koshiro , Matsueda Takahiro , Kashima Yuji , Kida Katsuyuki
Published: February 2021

In this paper, in order to investigate friction coefficient and wear of PEEK-PTFE hybrid radial bearings, rolling contact fatigue tests were performed under radial loads ranging from 93N to 387N at 600rpm in dry conditions. It was found that friction coefficients were 0.013 to 0.032 throughout the tests. Operation temperature followed the change in the friction coefficient, and PEEK-PTFE radial ball bearings exhibited stable performance even though the temperature locally approached 100 °C due to frictional heat. Moreover, wear loss of bearing components excluding alumina balls increased exponentially with increase of load.
Computational Analysis of Laser Cladding of Preset MCrAlY Coating Based on ANSYS I-Temperature Field
Authors: Wang Dong Sheng , Yue Li Ye , Yang Hao , Zhang Pei Pei
Published: February 2021

A finite element model of temperature field for plasma spraying preset MCrAlY coating during laser cladding was constructed using ANSYS parametric design language (APDL) in accordance to characteristics of preset laser cladding. Influencing laws of laser cladding parameters on temperature field were analyzed. Results show that laser power influences temperature field of cladding samples more than laser scanning speed. Experimental results agree well with simulation results, which prove the accuracy and reliability of the constructed calculation model of temperature field. Heating and cooling laws in the laser cladding process could be mastered through this calculation model. Research conclusions provide some references to optimization parameters in preparing high-performance laser cladding coatings.
Effect of Different Carbon Materials on the Conductivity of Epoxy Resin Conductive Coatings
Authors: Li Guang Zhao , Feng La Jun , Zhai Zhe , Wang Fang Fang
Published: February 2021

In this work, the conductive coating was prepared by electrostatic spraying with graphene and Multi-walled carbon nanotube (MWCNTs) as conductive medium and epoxy resin powder as film-forming material, in order to solve the pro·blem of high content and uneven dispersity of conductive particles in conductive coatings prepared by brushing method. The resistance of the coating was measured by four probe method, the dispersity of conductive particles in the coating was analyzed by scanning electron microscope (SEM), and the conductive mechanism of the coating was analyzed by percolation theory model. The results show that the conductive particles can be dispersed evenly in the whole coating by electrostatic force. Meanwhile, the electrostatic force can also stretch the conductive particles in the coating along the direction of the thickness of that. The flake graphene is vertically arranged in the coating, and the curled MWCNTs forms the conductive network of "island-bridge" structure. The conductive particles laped each other to form a conductive path, which greatly reduced the content of conductive particles. The seepage threshold of graphene conductive coating was only 1.5 wt.%, which lower than that of the MWCNTs conductive coating, which is 3 wt.%. The resistance of epoxy coating containing with 0.5 wt.% graphene is 3397 Ω·m, and that of epoxy coating containing with 0.5 wt.% MWCNTs is 1049 Ω·m.
Effect of Variation of Injection Molding Parameters on Static, Dynamic and Thermo-Mechanical Material Properties of Filled Polymer Materials
Authors: Contos Vaclav
Published: February 2021

A material (polymer + glass fibers) is characterized by its inhomogeneity and anisotropy. This material is subjected an injection molding simulation at first (generally unnewton type of fluid). Then the material is cooled and common structural analysis (static, dynamic and thermal) is performed. The cooled material has dissimilar mechanical properties for each of discrete element. Thus the mechanical properties (after simulation of load) will completely have different values when influence of injection molding is included.
Water Sorption and Solubility of Vanillin-Incorporated Self-Curing Orthodontic Polymethylmethacrylate Resin
Authors: Poonpiriya Thongchai , Sawaengkit Pornrachanee , Churnjitapirom Pornkiat , Thaweboon Sroisiri
Published: February 2021

Polymethylmethacrylate (PMMA) resin is one of the most commonly used materials for fabricating the base of removable orthodontic appliances. It is known that PMMA resin can promote the adhesion of microbes due to its surface porosity and from long-term use. Vanillin-incorporated PMMA resin has been reported to have antimicrobial effects against Candida albicans. However, the influence of vanillin incorporation on the water sorption and solubility of self-curing orthodontic PMMA resin has not been studied. Objective: To determine the water sorption and solubility of self-curing orthodontic PMMA resin incorporated with different concentrations of vanillin. Materials and methods: Three groups of self-curing orthodontic PMMA resin incorporated with 0.1% and 0.5% vanillin as well as PMMA without vanillin as a control were prepared with ten specimens per group. Water sorption and solubility tests were performed according to ISO 20795-2:2013 specifications. One-way ANOVA and Tukey’s multiple comparison tests at a p<0.05 significance level were used to analyse the data. Results: All three groups met ISO standard requirements. The means of water sorption values showed insignificant differences among the three groups even though the value of the 0.5% vanillin group tended to decrease. Water solubility of the 0.1% vanillin-incorporated group was not significantly different when compared with the control group whereas that of the 0.5% vanillin-incorporated group exhibited a significant lower value when compared with both control and 0.1% vanillin-incorporated groups. This suggests that increasing concentrations of vanillin would decrease the water solubility of PMMA resin. Conclusion: The incorporation of 0.5% vanillin into self-curing orthodontic PMMA resin could significantly reduce its water solubility and showed a trend of less water sorption property. Even with different vanillin concentrations, the water sorption and water solubility properties of PMMA resin were within the ISO standards. Nevertheless, further studies are recommended to determine the amount of residual monomer present in different concentrations of vanillin-incorporated PMMA resin.
Impact of Repetitive Recycling on Optical Properties of Virgin and Recycled Polypropylene Blends Based on Material Value Conservation Paradigm
Authors: Gabriel Djoko Sihono , Saragih Roben Hotdysah Putra
Published: February 2021

Implementation of material value conservation (MVC) needs to be proven through research to determine impact upon plastic properties such as optical properties of virgin plastic and recycled plastic blends. Optical properties such as colour, transparency and gloss are important parameters for appropriate quality of plastic packaging. Degradation of optical properties occurs during recycling processes of plastic materials and the declining properties of recycled products could be improved by blending them with virgin materials. This research aims to reveal the impact of repetitive recycling on optical properties of virgin and recycled polypropylene (PP) blends based on MVC paradigm. The first step of this research was to determine composition of virgin PP and recycled PP blends. Proportion of 70% virgin PP and 30% recycled PP was selected as a blend composition. The next step of this research was repetitive recycling of virgin PP and recycled PP blends with implementation of MVC up to the 8th recycling stage. The specimens of plastic blends were made from the 1st, 2nd, 4th and the 8th recycling stage and then their optical properties were tested with the American Society for Testing Materials (ASTM) methods. Generally, degradation level of optical properties will increase during the recycling processes. Testing results show a slightly change of colour properties. Degradation level of gloss properties is gradually increased by a maximum degradation level at the 8th recycling stage as 17.46%. However, transparency had a maximum degradation level at the 4th recycling stage as 20.93%. It means that the plastic blends can be used as viable raw materials based on their optical properties with more attention to the gloss. Furthermore, the implementation of MVC will provide more benefits through extending the life cycle of recycled products, reducing virgin plastic consumption, optimizing the use of plastic waste and reducing plastic waste generation.
A Mechanical Model for Polyhedral Oligomeric Silsesquioxane (POSS) Reinforced Amorphous Polyethylene
Authors: Li Yu Feng , Xiong Yan Yi , Fan Chen Yang , Wang Zhi Jun , Xiao You Cai
Published: February 2021

The mechanical behavior of polyethylene (PE) co-polymerized with polyhedral oligomeric silsesquioxane (POSS) was studied by using molecular simulations. Simulation configurations consisted of aligned PE chains with POSS attached to the central chain and amorphous PE chains with different content POSS. From the simulations with aligned PE chains with POSS, it was found that the method for reinforcement was due to dislocation pile-up at POSS, and above a critical stress the dislocations traverse the POSS causing a sawtooth variation in the load-displacement curve. The stress-strain curves for amorphous PE-POSS bulk showed distinct elastic and plastic straining stages. Plastic straining consisted of hardening and slipping segments attributed to dislocation pile-up and chain sliding. Computational results were used to develop a reinforcement model to describe the mechanical response of PE-POSS bulk under uniaxial tension.
Numerical Analysis of Microstructure Development during Laser Welding Nickel-Based Single-Crystal Superalloy Part I: Stray Grain Formation
Authors: Gao Zhi Guo
Published: February 2021

The mathematical modeling of microstructure development is further extended through coupling of heat transfer model and columnar/equiaxed transition (CET) model during nickel-based single-crystal superalloy weld pool solidification with different welding conditions (laser power, welding speed and welding configuration). It is indicated that crystallographic orientation plays an important role in stray grain formation ahead of the solid/liquid interface on the basis of constitutional undercooling mechanism. (001) and [100] welding configuration promotes symmetrical distribution of microstructure morphology about the weld pool centerline that is favored for reduction of stray grain formation, while detrimental (001) and [110] welding configuration induces asymmetrical distribution of microstructure morphology with more stray grain formation and deteriorates the weldability. The mechanism of increasing stray grain formation due to misorientation of dendrite growth crystallography is proposed. Appropriate low heat inputs (low laser power or high welding speed) of solidification conditions prevents stray grain formation and vice versa, and suppress the size of vulnerable [100] dendrite growth region. Weld pool geometry, θ-φ of solid/liquid interface, morphology transition and stray grain formation on either side of weld are closely correlated. In order to eliminate stray grain formation through microstructure control, it is imperative to optimize the welding configurations for defect-free weld through useful welding configuration-microstructure map. The theoretical predictions are verified by the experiment results in a consistent way. In addition, the model is also applicable to other single-crystal superalloys with similar metallurgical properties by feasible laser welding or laser cladding.
The original description of Sylvia melanocephala (Aves: Sylviidae), with notes on David Piesch’s birds of Sardinia (1784)
Authors: Mlíkovský Jiří
Published: February 2021

The name of the Sardinian Warbler Sylvia melanocephala is usually attributed to Gmelin (1789), but it dates from Piesch (1784). The correct name of the Sardinian Warbler is thus Sylvia melanocephala (Piesch, 1784). Comments are added on other bird species described by Piesch (1784) from Sardinia.
A Novel Therapy for Influenza-Induced Pneumonia
Authors: Cuttler Jerry M. , Calabrese Edward J.
Published: February 2021

This article recommends incorporating low-dose, lung radiation therapy into the treatment strategy for patients hospitalized with pneumonia due to influenza. This proposal is based on the history of 863 patients with severe bacterial or viral pneumonia. The lives of 717 of these patients were saved by the application of one X-ray treatment to their lungs. Since many tens of thousands of people die every year from influenza, complementary treatments that are safe and effective are needed. Low-dose radiation should become a life-saving component to the overall clinical patient management for this condition.
Real-World Clinical Outcomes and Prognostic Factors for Patients with Advanced Angiosarcoma who Received Systemic Treatment
Authors: Park Changhee , Kim Miso , Kwak Yoonjin , Moon Kyung Chul , Kim Se Hyun , Keam Bhumsuk , Kim Yu Jung , Kim Tae Min , Kim Dong-Wan
Published: February 2021

PurposeAngiosarcoma is a highly aggressive mesenchymal tumor. Although systemic chemotherapy is often considered for the inoperable or metastatic angiosarcoma, the outcome of such treatment is unsatisfactory and poorly delineated. Materials and MethodsWe reviewed electronic medical records of 75 patients with angiosarcoma who were treated with systemic chemotherapy for inoperable or metastatic disease. Patients were classified as having liver involvement if they had either primary or metastatic hepatic lesions. ResultsAmong the patients evaluated, 51 patients were male (68%) and 24 patients (32%) had primary cutaneous angiosarcoma. Liver involvement was present in 28 patients (37.3%). A total of 59 patients received first-line weekly paclitaxel (wPac) and showed an objective response rate (ORR) of 23.7% (n=14), a median progression free survival (mPFS) of 4.0 months (95% confidence interval [CI] 3.0–6.1), and a median overall survival (mOS) of 10.2 months (95% CI 7.0–14.6). Among patients without liver involvement, patients receiving wPac (n=35) had significantly prolonged mPFS (5.8 vs. 3.2 months, respectively, p=0.014) with a tendency for prolonged mOS (13.8 vs. 11.6 months, respectively, p=0.13) than those receiving other regimens (n=12). A total of 24 patients received second- or later-line pazopanib monotherapy and showed an ORR of 16.7% (n=4), a mPFS of 2.4 months (95% CI 1.8–4.3) and a mOS of 5.4 months (95% CI 3.5–NA). ConclusionTreatment with first-line wPac and later-line pazopanib seems to provide survival benefit, especially for patients with advanced angiosarcoma without liver involvement.
Chagas Disease in the United States: A Perspective on Diagnostic Testing Limitations and Next Steps
Authors: Hochberg Natasha S. , Wheelock Alyse , Hamer Davidson H. , Marcus Rachel , Nolan Melissa S. , Meymandi Sheba , Gilman Robert H.
Published: February 2021

Chagas disease is a neglected tropical disease that affects an estimated 300,000 people in the United States. This perspective piece reviews diagnostic challenges and proposes next steps to address these shortfalls.
Reforma educativa 2019: retos y perspectivas.
Authors: González Ortega Braulio
Published: February 2021

Once han sido las reformas constitucionales en materia educativa formalizadas a nivel constitucional en materia educativa desde la aprobación de nuestra carta magna por el Congreso Constituyente de 1917, de las cuales seis se han efectuado en el presente siglo. Lo anterior significa que durante 83 años se modificó el artículo tercero, cinco veces, y en tan sólo veinte años del presente siglo seis reformas. En medio de este proceso de derecho positivo sostenemos que en lo concreto del aula es el maestro el actor principal que reforma a las reformas. De ahí, la urgente necesidad de capacitación por parte de la autoridad educativa para que los principios, postulados, alcances, y metodologías puedan permear el quehacer docente.
Toma de decisiones durante la pandemia de COVID 19 desde el modelo de la teoría prospectiva en una muestra de colombianos.
Authors: Pérez Rivero Paula Fernanda
Published: February 2021

La teoría prospectiva ha sido un marco de referencia para la comprensión de la toma de decisiones humanas diferentes contextos. Esta investigación describe las preferencias de riesgo de un grupo de colombianos durante la pandemia por COVID 19 basándose en los postulados de la teoría prospectiva. Se evaluó en participantes anónimos las preferencias de riesgo mediante una encuesta en línea. Se encontró, que contrario a la teoría prospectiva, las preferencias de riesgo se distribuyen de forma equiparable en buscadores y aversos. Se hallaron diferencias entre hombres y mujeres que mostraron que las mujeres no sólo son más aversas que los hombres, sino que sus preferencias de riesgo se modifican en condiciones de pérdida en comparación con situaciones de ganancia.
La Nueva Realidad de la Educación Superior como derecho humano ante el COVID-19.
Authors: Contreras Hernández Helen , Cortina Saint André Marco Antonio
Published: February 2021

Hasta el año 2019, podíamos optar por un sistema de educación superior escolarizada o a distancia de acuerdo con nuestras necesidades. Sin embargo, a fines de marzo del año 2020, de una manera drástica se transformó el modo de impartir Educación Superior, implementándose como medida urgente un modelo de enseñanza híbrido preponderando la educación virtual, para la que no existía suficiente preparación. Ésta fue la solución a una problemática que persiste, a fin de dar continuidad y cumplir con el derecho humano de acceso a la educación, colocándose la instrucción al alcance de todos los universitarios. En el presente estudio nos interesa destacar específicamente, la nueva realidad de la Educación Superior como derecho humano ante el COVID-19.
Depresión, afrontamiento y rendimiento académico en estudiantes de Psicología.
Authors: Cuamba Osorio Nehemías , Zazueta Sanchez Nitzia Astrid
Published: February 2021

Partiendo del objetivo general: Identificar la presencia de indicadores de depresión y habilidades de afrontamiento analizando las diferencias de las variables entre grupos de rendimiento académico en estudiantes de psicología, se estructuró una investigación cuantitativa y transversal. A una muestra de 181 estudiantes se aplicó la escala BDI-II y CSI analizando los datos con estadísticos como T de Student. Resultados: se observó que el nivel de prevalencia de depresión en los estudiantes es alto, y las habilidades de afrontamiento bajo; además, la hipótesis de diferencias entre las variables por grupo de rendimiento académico fue nula, lo cual es probable que el rendimiento sea un factor protector como forma de distraerse de una realidad que los estudiantes perciben como molesta.