bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of Variant Adaptable LSTM Trained With Metaheuristic Algorithms for Healthcare Analysis
Authors: Rashid Tarik A. , Hassan Mohammad K. , Mohammadi Mokhtar , Fraser Kym
Published: January 2021

Recently, the population of the world has increased along with health problems. Diabetes mellitus disease as an example causes issues to the health of many patients globally. The task of this chapter is to develop a dynamic and intelligent decision support system for patients with different diseases, and it aims at examining machine-learning techniques supported by optimization techniques. Artificial neural networks have been used in healthcare for several decades. Most research works utilize multilayer layer perceptron (MLP) trained with back propagation (BP) learning algorithm to achieve diabetes mellitus classification. Nonetheless, MLP has some drawbacks, such as, convergence, which can be slow; local minima can affect the training process. It is hard to scale and cannot be used with time series data sets. To overcome these drawbacks, long short-term memory (LSTM) is suggested, which is a more advanced form of recurrent neural networks. In this chapter, adaptable LSTM trained with two optimizing algorithms instead of the back propagation learning algorithm is presented. The optimization algorithms are biogeography-based optimization (BBO) and genetic algorithm (GA). Dataset is collected locally and another benchmark dataset is used as well. Finally, the datasets fed into adaptable models; LSTM with BBO (LSTMBBO) and LSTM with GA (LSTMGA) for classification purposes. The experimental and testing results are compared and they are promising. This system helps physicians and doctors to provide proper health treatment for patients with diabetes mellitus. Details of source code and implementation of our system can be obtained in the following link “https://github.com/hamakamal/LSTM.”
Applications of Machine Learning in Disease Pre-screening
Authors: Kumar Upendra
Published: January 2021

Computers in disease prescreening are utilized to interpret medical information. This is known as computer-aided pre-screening tool (CAPST). CAPST helps in improving the accuracy of diagnosis in medicine. The medical experts usually take the outcome of the CAPST as a second opinion to make the final diagnostic decisions. Fast and accurate prediction of disease risk and diagnosis is crucial step for the successful treatment of an individual. The AI-based machine learning technology has undergone significant developments over the past few years and is successfully used in many intelligent applications covering problems of variety of domains. One of the most stimulating questions is whether these techniques can be successfully applied to medicine in disease pre-screening and diagnosis and what kind of data it requires to be trained and learned. There are so many real-time examples of the problems where machine learning methods are applied successfully, especially in medicine. Many of them showed significant improvement in classification accuracy.
Cybersecurity Standardisation for SMEs
Authors: Ozkan Bilge Yigit , Spruit Marco
Published: January 2021

There are various challenges regarding the development and use of cybersecurity standards for SMEs. In particular, SMEs need guidance in interpreting and implementing cybersecurity practices and adopting the standards to their specific needs. As an empirical study, the workshop Cybersecurity Standards: What Impacts and Gaps for SMEs was co-organized by the StandICT.eu and SMESEC Horizon 2020 projects with the aim of identifying cybersecurity standardisation needs and gaps for SMEs. The workshop participants were from key stakeholder groups that include policymakers, standards developing organisations, SME alliances, and cybersecurity organisations. This paper highlights the key discussions and outcomes of the workshop and presents the themes, current initiatives, and plans towards cybersecurity standardisation for SMEs. The findings from the workshop and multivocal literature searches were used to formulate an agenda for future research.
Measuring Security
Authors: Jaiswal Shruti , Gupta Daya
Published: January 2021

The researchers have been focusing on embedding security from the early phases of software development lifecycle. They have researched and innovated a field of Security Engineering where security concerns are embedded during requirement, design, and testing phases of software development. Efforts were made in developing methods, methodologies, and tools to handle security issues. Various methods are present in the literature for eliciting, analyzing and prioritizing the security requirements. During the design phase based on prioritized requirements, environment parameters and attribute a suitable security algorithm mainly cryptography algorithms are identified. Then a question arises how to test the effectiveness of chosen algorithm? Therefore, as an answer to the issue in this paper, a process for Security Testing is presented that evaluates the selected security algorithms. Evaluation is done by generating the test scenarios for functionalities using sequence diagram representing the threats at vulnerable points. Then, checking the mitigation of potential threats at identified vulnerable points. A security index is generated which shows the effectiveness of deployed/ chosen security algorithm. The process ends with the generation of a test report depicting the testing summary. For a clear understanding of the process, the proposal is illustrated with a case study of the cloud storage as a service model.
Analysis of Color Image Encryption Using Multidimensional Bogdanov Map
Authors: Parida R. N. Ramakant , Singh Swapnil , Pradhan Chittaranjan
Published: January 2021

Image encryption is a main concern in digital transmission of data over communication network. As encryption and decryption of image has got considerable attention in the past decades, its effectiveness and compatibility need to be taken care of. The work reported in this chapter is mainly concerned with enhancement of dimension in image encryption technique. The work mainly deals with pixels shuffling of an image using Bogdanov chaotic map for both gray and color image, where encryption and decryption process are associated with the key. In color image, the image is divided into all three planes (RGB) individually. Scrambling is done with all three planes individually. All the three planes are summed up into a single plane which gives us the final result. In Bogdanov map, old pixel position is replaced with new pixel position. Further, the authors analyzed security of image encryption techniques with two parameters called NPCR and UACI. The efficacy of the encryption process can be seen in experimental results.
Deep Reinforcement Learning for Optimization
Authors: Hasan Md Mahmudul , Rahman Md Shahinur , Bell Adrian
Published: January 2021

Deep reinforcement learning (DRL) has transformed the field of artificial intelligence (AI) especially after the success of Google DeepMind. This branch of machine learning epitomizes a step toward building autonomous systems by understanding of the visual world. Deep reinforcement learning (RL) is currently applied to different sorts of problems that were previously obstinate. In this chapter, at first, the authors started with an introduction of the general field of RL and Markov decision process (MDP). Then, they clarified the common DRL framework and the necessary components RL settings. Moreover, they analyzed the stochastic gradient descent (SGD)-based optimizers such as ADAM and a non-specific multi-policy selection mechanism in a multi-objective Markov decision process. In this chapter, the authors also included the comparison for different Deep Q networks. In conclusion, they describe several challenges and trends in research within the deep reinforcement learning field.
Strengthening Cybersecurity in Singapore
Authors: Luk Ching Yuen
Published: January 2021

This chapter uses a historical perspective to examine the development trajectory of e-government in Singapore, the trends and patterns of cybercrimes and cyber-attacks, and the measures taken by the government to combat cybercrimes and cyber-attacks. It shows that the government has adopted a proactive, holistic, and cooperative approach to cybersecurity in order to tackle the ever-increasing cybersecurity challenges. It has regularly reviewed and improved cybersecurity measures to ensure their effectiveness and strengthened its defense capabilities over time through coordinating national efforts with public and private sectors and cooperating with regional and international counterparts. The chase for a perfect cybersecurity system or strategy is both impossible and unnecessary. However, it is important and necessary to establish a cybersecurity system or formulate a cybersecurity strategy that can monitor, detect, respond to, recover from, and prevent cyber-attacks in a timely manner, and make the nation stronger, safer, and more secure.
Artificial Intelligence and Big Data Analytics in Support of Cyber Defense
Authors: Leenen Louise , Meyer Thomas
Published: January 2021

Cybersecurity analysts rely on vast volumes of security event data to predict, identify, characterize, and deal with security threats. These analysts must understand and make sense of these huge datasets in order to discover patterns which lead to intelligent decision making and advance warnings of possible threats, and this ability requires automation. Big data analytics and artificial intelligence can improve cyber defense. Big data analytics methods are applied to large data sets that contain different data types. The purpose is to detect patterns, correlations, trends, and other useful information. Artificial intelligence provides algorithms that can reason or learn and improve their behavior, and includes semantic technologies. A large number of automated systems are currently based on syntactic rules which are generally not sophisticated enough to deal with the level of complexity in this domain. An overview of artificial intelligence and big data technologies in cyber defense is provided, and important areas for future research are identified and discussed.
Risk and Security of Information Systems in the Portuguese Financial Sector
Authors: Fernandes da Anunciação Pedro , Rodrigues Alexandre Miguel Barão
Published: January 2021

This work follows the need of safety standards, update ISO27002:2013, in the major central banks of several European countries. This need has been studied by establishing a focus group that integrated European experts from major central banks. The analysis carried out was supported in the current methodology of information risk management, used by central banks in the safety management of information systems. This methodology is used to analyze and evaluate the adequacy of practices to risk management in the financial activity. The main objective was to present a proposal, sufficiently comprehensive and consistent, to a new risk management process of Information Systems within the European System of Central Banks. And a definition of a practical guide to risk management throughout the different stages of the Information Systems Life Cycle. The proposed model provides a higher degree of protection systems, technologies and information, especially in Central Banks, taking as reference the Portuguese Central Bank.
The Role of Artificial Intelligence in Cyber Security
Authors: Bhatele Kirti Raj , Shrivastava Harsh , Kumari Neha
Published: January 2021

Cyber security has become a major concern in the digital era. Data breaches, ID theft, cracking the captcha, and other such stories abound, affecting millions of individuals as well as organizations. The challenges have always been endless in inventing right controls and procedures and implementing them with acute perfection for tackling with cyber attacks and crimes. The ever-increasing risk of cyber attacks and crimes grew exponentially with recent advancements in artificial intelligence. It has been applied in almost every field of sciences and engineering. From healthcare to robotics, AI has created a revolution. This ball of fire couldn't be kept away from cyber criminals, and thus, the “usual” cyber attacks have now become “intelligent” cyber attacks. In this chapter, the authors discuss specific techniques in artificial intelligence that are promising. They cover the applications of those techniques in cyber security. They end the discussion talking about the future scope of artificial intelligence and cyber security.
Strategic Data and Cyber Security Management in the Arab World
Authors: Al Issa Ayman
Published: January 2021

The chapter discusses strategic technological advancements such as automation, digitalization, digital transformation, data science, data analytics, real-time data acquisition, artificial intelligence, and predictive intelligence, and how all these aspects are affecting the lives of people in the Arab world. In particular, the study highlights the sheer importance for Arab governments and business organization to answer the emerging cyber challenge and how Arab businesses and people can utilize these technology advancements in a safe and secure way.
Challenges Facing Technology Standardization in the Age of Digital Transformation
Authors: McAuliffe Brian
Published: January 2021

It is widely recognized that we are in rapid transition to the so-called fourth industrial revolution, a world of digitalization and mass interconnectedness enabled by a plethora of emergent powerful technologies including artificial intelligence (AI), internet of things (IoT), and distributed ledgers (DLT). A key element of this “revolution” is the move to digital manufacturing. While undoubtedly exciting, this transition presents challenges to policymakers, industry, and societal stakeholders alike. One such challenge is defining an optimum level for any market intervention measure(s), such that a balance is struck between ensuring a pro-industrial and economic innovation-friendly approach and guaranteeing adequate levels of consumer-focused protection. Standardization can be leveraged as one element of interventionary policy designed to help strike the required balance, both in its well-proven bottom-up and industry-led voluntary application and as a tool to support implementation of regulations. With a focus on digital transformation, this chapter will analyze the readiness of the current standardization system to support this significant transition focusing on strengths and challenges to be addressed from the perspective of industry, policymakers, and standards-setting organizations.
Security in Context of the Internet of Things
Authors: Banday Mohammad Tariq
Published: January 2021

The chapter discusses various security challenges in the design of the internet of things and their possible solutions. After presenting a precise introduction to the internet of things, its applications, and technologies enabling it, the chapter discusses its various architectures and models which follow with an introduction of development kits, boards, platforms, hardware, software, and devices used in the internet of things. A concise explanation and discussion on the internet of things standards and protocols with emphasis on their security is presented. Next, various possible security threats and attacks to the internet of things are presented. The subsequent sections of the chapter discuss identified security challenges at individual layers of various models along with their possible solutions. It further presents cryptographic and lightweight cryptographic primitives for the internet of things, existing use of cryptography in the internet of things protocols, security challenges, and its prospectus.
Effects of Team Collaboration on Sharing Information Security Advice
Authors: Dang-Pham Duy , Nkhoma Mathews
Published: January 2021

Active sharing of information security advice among the employees has undeniable implications for developing a sustainable security environment. This research examines this topic from the network perspective, and focuses on the work relationships that promote sharing security advice. Exponential random graph modeling technique was employed to evaluate the relationship between team collaborative activities and sharing security advice. The findings revealed that those who share security advice also tend to give work- and IT-related knowledge. Moreover, employees who have similar tenure tend to exchange security advice with each other more. Furthermore, the network of sharing security advice is transitive and has a tendency to form separate clusters. Security managers are suggested to take into account the research findings to identify key employees who frequently share security advice in the workplace and devise appropriate strategies to manage them.
Machine Learning in Wireless Communication
Authors: Sharma Neha Vaishnavi , Yadav Narendra Singh
Published: January 2021

As the circumstances are changing, mankind has turned out to be more inclined to snappy and speedier correspondence and access to information. The correspondence happens in numerous structures (e.g., presently, this correspondence is all the more a virtual substance than a physical one). So as to keep up fast correspondence, the coming age will depend on exceptionally tried and true, canny and self-learning/self-modifying correspondence organizers. In this context, this chapter reviews the most important machine learning techniques with the direct applicability in wireless ad-hoc systems. A guide of machine learning methods and their relevance is also provided. Different applications of ad-hoc wireless networks are discussed in terms of energy-aware communications, optimal node deployment and localization, resource allocation, and scheduling.
The Big Data Research Ecosystem
Authors: Strydom Moses John , Buckley Sheryl
Published: January 2021

Big data is the emerging field where innovative technology offers new ways to extract value from an unequivocal plethora of available information. By its fundamental characteristic, the big data ecosystem is highly conjectural and is susceptible to continuous and rapid evolution in line with developments in technology and opportunities, a situation that predisposes the field to research in very brief time spans. Against this background, both academics and practitioners oddly have a limited understanding of how organizations translate potential into actual social and economic value. This chapter conducts an in-depth systematic review of existing penchants in the rapidly developing field of big data research and, thereafter, systematically reviewed these studies to identify some of their weaknesses and challenges. The authors argue that, in practice, most of big data surveys do not focus on technologies, and instead present algorithms and approaches employed to process big data.
A Literature Review on Image Encryption Techniques
Authors: Geetha S , Punithavathi P , Infanteena A Magnus , Sindhu S Siva Sivatha
Published: January 2021

Encryption is one of the techniques that ensure the security of images used in various domains like military intelligence, secure medical imaging services, intranet and internet communication, e-banking, social networking image communication like Facebook, WhatsApp, Twitter etc. All these images travel in a free and open network either during storage or communication; hence their security turns out to be a crucial necessity in the grounds of personal privacy and confidentiality. This article reviews and summarizes various image encryption techniques so as to promote development of advanced image encryption methods that facilitate increased versatility and security.
Novel Cryptography Technique via Chaos Synchronization of Fractional-Order Derivative Systems
Authors: Tene Alain Giresse , Kofane Timoleon Crépin
Published: January 2021

Synchronization of fractional-order-derivative systems for cryptography purpose is still exploratory and despite an increase in cryptography research, several challenges remain in designing a powerful cryptosystem. This chapter addresses the problem of synchronization of fractional-order-derivative chaotic systems using random numbers generator for a novel technique to key distribution in cryptography. However, there is evidence that researchers have approached the problem using integer order derivative chaotic systems. Consequently, the aim of the chapter lies in coding and decoding a text via chaos synchronization of fractional-order derivative, the performance analysis and the key establishment scheme following an application on a text encryption using the chaotic Mathieu-Van Der Pol fractional system. In order to improve the level of the key security, the Fibonacci Q-matrix is used in the key generation process and the initial condition; the order of the derivative of the responder system secretly shared between the responder and the receiver are also involved. It followed from this study that compared to the existing cryptography techniques, this proposed method is found to be very efficient due to the fact that, it improves the key security.
Between the Devil and the Deep Blue Sea
Authors: Joshua Segun , Samuel Sunday Idowu  , Olanrewaju Faith Osasumwen
Published: January 2021

The world is currently faced with the problem of refugees and internally displaced persons (IDPs). Africa and Middle East has the highest figure of IDPs. Nigeria tops the list of countries with largest population of IDPs in Africa. The Boko Haram insurgency has made Nigeria one of the flash points of high concentration of IDPs. Anchored on forced /involuntary migration theory, using primary and secondary data gathering techniques, the study examines insurgency and conditions of IDPs camps in Nigeria, focusing on NYSC camp in Girei Local Government, Adamawa State. The study finds that the condition in NYSC IDP camp is deplorable as IDPs lack access to basic essentials of life. The study recommends among others the need for the government to be more committed to the welfare of IDPs and also curb corruption of government officials in the camp as this has worsen the already deplorable condition of IDPs.
Dimensional Entrepreneurial Deployment of Information and Communication Technology for Economic Empowerment in Nigeria
Authors: Adesokan Okanlade , Adebowale Lawal , Oyekunle Olalekan
Published: January 2021

The success of entrepreneurship practice largely depends on the opportunities provided by an environment and the intuition and innovativeness of the enterprising individuals to leverage on the opportunities. The emerging information and communication technologies (ICT) in Nigeria brought about arrays of opportunities for ICT entrepreneurship practice in the country. Conscientious examination of the dimensional exploration of the information-driven technologies for economic activities among the enterprising individuals revealed extensive exploitation for fast-tracking online businesses and merchandising of ICT resources. Socioeconomic impacts of the ICT entrepreneurship thus range through increased employment opportunity in the informal sector to satisfaction of basic needs of such employees. The need to strengthen the ICT sector through enabling policy for economic growth of the micro, small and medium entrepreneurs is recommended.
Dual-Factor Approach to Consumer Acceptance of Mobile Banking
Authors: Amoroso Donald , Sato Osam , Ackaradejruangsri Pajaree
Published: January 2021

This study builds on relationship marketing literature and extends existing continuance intention theories by applying dual-factor model to understand the complex behaviors of Japanese consumers and continuance intention of using mobile financial applications, such as mobile banking and/or mobile wallet. The research model, originally developed by Amoroso and Chen, has been adopted and data collected with a sample of 513 Japanese mobile banking app consumers. A predictive structural equation model was derived from the covariance matrix and was produced to analyze the path coefficients. The results show a general support for continuance intention to use mobile banking technologies among Japanese consumers. The results show Japanese consumer satisfaction is found to be a strong predictor of loyalty and continuance intention, directly affected by perceived value, perceived enjoyment, and inertia/habit. While loyalty is found to be a key construct to directly affect continuance intention, a very strong predictor of continuance intention among Japanese mobile banking apps users.
Issues and Adoption Barriers in Wearable Technologies
Authors: Padyab Ali , Habibipour Abdolrasoul
Published: January 2021

The rapid growth of the Internet of Things (IoT) has given rise to many wearable devices integrated into daily life. However, achieving end-users' long-term adoption is still an issue. While wearables' technological implementation is advancing rapidly, their consequences need to be scrutinized to alleviate the concerns that threaten a strong civil and sustainable society. The purpose of this article is to investigate issues (social, ethical, and ecological) and adoption barriers related to wearable technologies from end-users' perspectives. The authors undertook a systematic literature review combined with two rounds of interviews with domain experts as well as end-users of IoT wearable devices to find relevant issues and adoption barriers. This article summarizes social, ethical, and ecological issues as well as adoption barriers of wearable technologies. These issues and adoption barriers have important implications that need to be addressed to increase the adoption and diffusion of wearable technologies.
Numerical Investigation of Orifice Shape Effect on the Flow Behavior of the Jet-Cavity Interaction
Authors: Boualem Khadidja
Published: January 2021

The aim of the present work is to analyze the effect of orifice shape on wall jet development to enhance the impingement heat transfer in confined cavity with the validated model of hot and cold jet using computing code ANSYS.CFX. Circular, elliptic, square and rectangular are the investigated orifice shapes, that they have the same hydraulic diameter Dh = 0.12m. Another objective of this paper is to investigate the influence of Reynolds number based on the mean jet splay and diffuser hydraulic diameter. The validation of results shows qualitatively good agreement and almost all flow structures are well reproduced by the computation. The results show that the orifice shape affects the flow and the heat transfer coefficient in the cavity. The elliptical shape gives an accelerated flow, which provides better heat transfer enhancement of 7% than that the circular diffuser.
Numerical Assessment of Turbulent Flow Driving in a Two-Sided Lid-Driven Cavity with Antiparallel Wall Motion
Authors: Azzouz El Amin , Houat Samir , Dellil Ahmed Zineddine
Published: January 2021

In this paper, the case of the steady two-dimensional flow in a two-sided lid-driven square cavity is numerically investigated by the finite volume method (FVM). The flow motion is due to the top and bottom horizontal walls sliding symmetrically in the opposite direction with equal velocities, UT and UB, obtained through three respective Reynolds numbers, Re1,2=10000, 15000, and 20000. Due to the lack of availability of experimental results in this Reynolds number margin for this type of flow, the problem is first examined by considering that the flow is turbulent with the inclusion of four commonly used RANS turbulence models: Omega RSM, SST k-ω, RNG k-ε and Spalart-Allmaras (SA). Next, the regime is considered being laminar in the same range of Reynolds numbers. A systematic evaluation of the flow characteristics is performed in terms of stream-function contour, velocity profiles, and secondary vortices depth. Examination of the calculation results reveals the existence of a great similarity of the predicted flow structures between the Omega RSM model and those from the laminar flow assumption. On the other hand, the computed flow with the SST k-ω model, the RNG k-ε model, and the SA model reveals a remarkable under-prediction which appears clearly in the size and number of secondary vortices in the near-wall regions. Various benchmarking results are presented in this study.
Electrodeposited Ni-Co Films from Electrolytes with Different Co Contents
Authors: Herzallah Ouahiba , Temam Hachemi Ben , Ababsa Asma , Gana Abderrahmane
Published: January 2021

Ni–Co alloy coatings were electrodeposited at various cobalt amounts on pretreated steel substrates. The co-deposition phenomenon of Ni-Co alloys was described as anomalous behaviour. Different techniques including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD) and potentiodynamic polarization were used to characterize the alloy coatings. EDX results showed that the Co content increase with the enhancing of Co amount. SEM images have shown that the increase of Co amount leads grain developing from large grain to branched grain form and that goes through spherical and pyramidal, this implies that the grain size of these alloy coatings is greatly affected by Co amount in the electrolyte baths. XRD patterns revealed that the phase structure of Ni–Co coatings is dramatically changed from fcc into hcp structure with the increase of Co amount. The electrochemical properties of Ni-Co alloy coatings evaluated in 3.5% NaCl solution reveal that Ni–34.32 wt.% Co alloy exhibits better corrosion resistance compared to pure Ni and other Ni–Co alloy coatings.
Propolis Extract as Corrosion Inhibitor of Iron Alloy Immersed in an Ethylene Glycol / Water, 0.1 M NaCl Solution
Authors: Hachelef Hakima , Khelifa Abdallah , Benmoussat Abderrahim
Published: January 2021

The behaviour of a corrosion inhibitor based on proplolis extract via an iron alloy immersed in an electrolyte containing ethylene glycol water in NaCl 0.1 M was evaluated by a stationary technique not destructive which is the technique of electrochemical impedance. The diameter of the Nyquist curves increases with the increase of the concentration of propolis extract and it reaches an optimum concentration at 1.25 g / L, the maximum surface coverage percent at this concentration is 71.98% .The activation parameters reveal that the inhibitor molecules on iron surface are absorbed by physisorption and a chimisorption and obey Langmuir isotherm adsorption. These results were supplemented by Scanning electron microscopy (SEM) and (EDX) spectrum of chemical composition. The metal solution interface is simulated as a physical model by using electrochemical impedance spectroscopy (EIS). Keywords: Iron Alloy, Propolis extract, ethylene glycol;, Lamgmuir isotherm, Electrochemical impedance Spectroscopy (EIS).
Optical, Structural and Spectroscopic Characterization of ZnS Nanocrystals Embedded in KBr Single Crystal Matrix Grown by Czochralski Method
Authors: Zeroual Soria , Mahboub Mohammed Sadok , Rihia Ghani , Mimouni Mourad , Mebrouk Ghougali , Sebais Miloud
Published: January 2021

ZnS nanocrystals were embedded in a KBr single crystal matrix using the Czochralski growth technique. The X-ray diffraction, FT-IR and optical spectroscopy revealed the incorporation of ZnS nanocrystals. A blue shift of the absorption edge of the obtained samples has been observed, indicating the quantum confinement effect. The optical band-gap is estimated to be about 4.67 eV. Two excitonic peaks appeared at 300.4 nm and 271 nm. The average nanocrystal size was derived from the optical spectra. Annealing led to a shift in the absorption edge towards longer wavelengths and an increasing of the emissions intensity. Raman lines of the nanoparticles are broader and frequency-shifted compared to those of the bulk crystals. These results show that KBr is a good matrix-host of ZnS nanocrystals, and that the elaborated samples can be used for important technological applications.
Optimization of Automatic TIG Welding Parameters of AISI 304L ASS Welds Using Response Surface Methodology
Authors: Saadi Tahar , Benlamnouar Mohamed Farid , Bensaid Nabil , Boutaghane Amar , Soualili Mohamed Amine , Hachemi Hania
Published: January 2021

The present study, aims to investigate, under welding parameters of current, voltage and gas flow, the effects of welding parameters on tensile strength of AISI 304L ASS welds using response surface methodology (RSM). The RSM and variance analysis (ANOVA) were used to check the validity of quadratic regression model and to determine the significant parameter affecting tensile strength of welds. Hence, ANOVA clearly revealed that the contribution of each factor is 71.40% of voltage, 19.2% of current and 8.30% of gas flow. It was found that combined contributions of welding parameters contributes significantly to the metallurgical changes by varying fractions, morphology and grain size of metallic compounds. Furthermore, the optimum automatic welding conditions lead to produce the best possible weld quality in the range of our experiment using desirability function approach for single response of RSM optimization factors, in which it concluded that tensile strength components are influenced principally by voltage. Finally, the ranges for best welding conditions are proposed for serial industrial production.
Improving Microhardness of AISI 316L Stainless Steel by Ball Burnishing- Optimization by BOX-BEHNKEN Model
Authors: Attabi Selma , Laouar Lakhdar , Mokhtari Madjda , Himour Abdelaziz , Elmsellem Hicham
Published: January 2021

In the field of mechanics and biomaterials, particular attention is directed to the finishing step of pieces because it conditions several properties of materials, namely surface quality and microhardness. The mechanical surface treatment (TMS) by burnishing is one among the most competent finishing operations aimed toward improving the characteristics of surface and also the lifetime of components. Although this treatment is extremely effective, but it is very necessary to choose the appropriate combination of process parameters to realize better results. This work aims to improve, by ball burnishing, the microhardness of 316L stainless steel used for the manufacture of biomedical hip prostheses. This property is vital because it directly influences other final properties such as tensile strength, wear resistance and fatigue life. The response surface method based on Box-Behnken model is followed for experiments and an empirical model expressing the relationship between microhardness and process parameters (burnishing force, feed rate, and ball diameter ) is developed. The optimal regime for maximum hardening is also established. The results show that burnishing treatment, carried out on a flat surface, makes it possible to significantly hardening the surface of 316L stainless steel by obtaining a greater value by up to 67% compared to the untreated surface. Scanning electron micrographs show a very thin surface layer containing grains deformed plastically in the burnishing direction.
Characterization of Concrete by Using Bulk Longitudinal Ultrasonic Waves at Low Frequencies- Correlation with Compressive Strength Testing
Authors: Slimani Hana , Cheniti Nesrine , Abdelli Kamal , Boutkedjirt Tarek
Published: January 2021

Concrete is a complex porous material. This porosity comes from the air trapped during mixing and also from the free water that did not react with the cement. In this work, we varied the porosity rate in concrete specimens, in order to evaluate its effect on the acoustic and mechanical properties of the material during its maturation age. These test pieces were made according to EN 196-1: 2016 of different dimensions and with three mass ratios Water/Cement (W/C=0.45, W/C=0.50 and W/C=0.65). The ultrasonic measurements were done in the direct transmission mode, using 54 kHz nominal frequency transducers, transmitting in the longitudinal mode. The results showed an increase in the propagation velocity with the age of maturation for all W/C ratios and an overall decrease in its value with this ratio. On the other hand, the attenuation coefficient increased slightly with the frequency in a quasi-linear manner, while its overall value decreased with the age of maturity of the concrete. For comparison, a destructive method was used. This consisted of crushing tests to determine the compressive strength. This latter increased with the age of maturation of the concrete for all W/C ratios, but decreased when these ratios increased. These results showed the same trend as those obtained for the ultrasonic group velocity. This allowed us to deduce a correlation law between the acoustical and mechanical parameters for all ratios with a high determination coefficient. These investigations confirm the effectiveness of ultrasonic methods in evaluating the quality of concrete.
Effect of Heat Treatment on the Structure, Wear and Corrosion of AISI L6 Tool Steel
Authors: Ghelloudj Oualid , Gharbi Amel , Zelmati Djamel , Bouhamla Khedidja , Ramoul Chems Eddine , Berdjane Djamel
Published: January 2021

This work is a contribution in analyzing structure, tribological behavior and corrosion of AISI L6 hardened tool steel. Structural characterization and tribological behavior of steel were investigated using Optical Microscopy (OM), Scanning electron microscopy (SEM), wear testing by friction on a pin-on-disc Tribometer and corrosion by potentiodynamic polarization. Comparing to the as-received steel, hardening has generated a fine martensitic microstructure causing a 1.5 times hardness increase. Hardening has contributed to improvement of wear resistance as the coefficient of friction has decreased from 0.86 to 0.67μ. An increase in corrosion resistance was observed after hardening treatment.
Contribution of the Tribal Study to the Effectiveness of the Wool Fiber Composite Compared to Fiberglass Composite Materials
Authors: Kacimi Noureddine , Tafraoui Ahmed
Published: January 2021

In the field of economic and ecological material research which can replace the composite material currently used in several fields such as glass wool, research leads to a comparison of the mechanical properties and the quality of plates made from recycled materials with those of glass wool, in particular in terms of surface condition and geometric precision thus. In this study, we recycled and used damaged wool fibers in a composite material; the results showed that the new product has mechanical characteristics similar to those of fiberglass composite materials. The recycling of wool fiber reduces the cost of a product made of composite materials, with the possibility of a later study of the machinability of the plates made from this material and its use in various sectors.
Effect of Fibers Orientation on the Fracture of Polymer Concrete Based on Quartz, Polyester and Jute Fabrics
Authors: Benkharbeche Houria , Rokbi Mansour , Rahmouni Zine El Abidine , Ghebouli Moustapha , Grine Madani , Baali Brahim
Published: January 2021

The main objective of this work is to highlight the influence of jute woven layer orientation on fracture parameters (energy release rate and stress intensity factor) of a polymer concrete laminate. The use of plant fibers, jute in this study, as reinforcements outside the polymer concrete, acquires mechanical properties, traction, and flexion, more than appreciable, however, other characteristics must be studied to ensure better integration on the market. The addition of plant fibers with different orientations is not without consequences on the mechanical behavior, in this case, on the resistance to cracking and its propagation. Fibered concretes have a very different behavior compared to non-fiber concretes, especially after the first cracking, where the fibers make their contribution by trying to stop the evolution and the propagation of micro-cracks within the matrix by making the concrete more ductile.
Experimental Study on Impact Resistance of Concrete Containing Steel Fibers
Authors: Younis Khaleel H. , Jirjees Firas F. , Yaba Hozan K. , Maruf Shelan M.
Published: January 2021

This study is an experimental study aims to examine the effect of utilization of straight, and low cost steel fibers on the impact resistance of concrete. The impact resistance of steel fiber reinforced concrete (SFRC) was assessed using drop weight test as per ACI committee 544. The steel fibers were randomly dispersed in concrete during mixing. Five mixes made with steel fibers dosages of 0% (control mix), 0.5%, 1%, 1.25% and 1.5% by volume of concrete were examined in the study. The results show that mixes containing steel fibers show better impact resistance than plain concrete (control Mix). The results also indicate that increasing the dosage of fiber increases the impact resistance of concrete but up to a certain content of fibers. The maximum increase was recorded at steel fiber dosage of 1.25% by volume of concrete. Also the patterns of failure of the concrete specimens show that fibers are very effective in increasing the concrete toughness which enhance the ductility of concrete and delays the crack initiation.
Identifying the Weight of Factors Affecting Creep of Concrete Using Factorial ANOVA
Authors: Daou Hikmat , Raphael Wassim
Published: January 2021

Creep may affect structural behavior by violating service limit states, redistributing stress or losing prestress forces. For that, knowing the significance of factors that influence creep is a must to accurately predict it. This paper uses the Northwestern university (NU) database to investigate the factors that most affect long-term creep of concrete. Factorial ANOVA was applied to identify the significance of factors affecting creep of concrete at 3000 days using R software. The factorial ANOVA results showed that the sustained load and the relative humidity have the major effect on the value of concrete creep at 3000 days.
Effects of Tungsten Doping on the Electrical Properties of Hydrothermally Synthesized Aluminum Niobate
Authors: Shimanouchi Rie , Matsumoto Yuhei
Published: January 2021

The conditions for the synthesis of aluminum tungstate Al2(WO4)3 and aluminum niobate AlNbO4 were clarified using hydrothermal treatment and post-heating. Single-phase Al2(WO4)3 can be synthesized through the hydrothermal treatment of the starting materials at a mixing ratio of Al:W = 5:5 at 250 °C for 5 h and post-heating at 840 °C for 6 h. The AlNbO4 was synthesized using the same method, under a hydrothermal treatment of Al:Nb = 2:8 and post-heating. As a result of investigating the products under various mixing conditions based on the synthesis of pure Al2(WO4)3 and AlNbO4, Nb could not be doped into Al2(WO4)3, but W-doped AlNbO4 was synthesized. The electric conductivity was measured for several samples of sintered W-doped AlNbO4, and the results showed that the electrical conductivity was improved within a higher temperature region by doping with W.
Biosynthesis of Silver Nanoparticles Using Banana Raja (Musa paradisiaca var. raja) Peel Extract: Effect of Different Concentrations of the AgNO3 Solution
Authors: Pratikno Hidayat , Anggya Pramita Basuki , Fadhila Febrianti , Chafidz Achmad , Wara Dyah Pita Rengga
Published: January 2021

This study focuses on the biosynthesis of silver nanoparticles using Banana Raja (Musa Paradisiaca Var. Raja) peel extract. The aim is to determine the effect of concentration differences of silver nitrate (AgNO3) as the precursor on the production of silver nanoparticles. In this study, banana peel extract (BPE) was reacted with AgNO3 solution at several concentrations of silver nitrate solution i.e. 0.125; 0.1; 0.075 and 0.05 M at temperature of 50 °C. The ratio of banana peel extract and AgNO3 solution used was 5:500 (v/v). The stirring was done by using a magnetic stirrer. The reaction took place when the color of the mixture (extract and AgNO3) changed until the color of the mixture became constant. The results of the colloidal silver nanoparticles were characterized using UV-Vis Spectrometer, while the functional groups of the banana extract was analyzed using a Fourier Transform Infra-Red (FT-IR) apparatus. Whereas, the morphology of the silver nanoparticles was studied using a Scanning Electron Microscopy (SEM). The UV-Vis Spectrometer result show that the concentration of AgNO3 which gave the highest absorbance value was at 0.1 M. The SEM micrographs could not clearly show the difference in the morphology of silver nanoparticles samples at different concentrations of AgNO3 solution.
Extraction of Essential Oil from Sedap malam Flower (Polianthes tuberosa) Using Methanol Solvent
Authors: Rusdi Suharno , Imtiyaz Farida , Wulandari Nopia Denvil , Chafidz Achmad
Published: January 2021

The objectives of this study are to obtain essential oil from Sedap Malam (Tuberose) flower via extraction method and to characterize the physical and chemical properties of the essential oil produced, such as density, rendement, and chemical composition. The extraction process was carried out by using methanol solvent. The ratio between Sedap Malam flower and the methanol solvent was 1:5. After the extraction process of the essential oil finished, the essential oil and the solvent were separated via a simple distillation process. The collected essential oil was then characterized using Gas Chromatography-Mass Spectrophotometry (GC-MS) apparatus and Fourier Transform Infra-Red (FT-IR) analysis to investigate the content of the essential oil extracted from Sedap Malam flower. The physical characterization results showed that the essential oil has average rendement value of 12.605 % and density value of 1.0905 g/mL. Additionally, organoleptic test was carried to test the response of respondents toward the color and odor/fragrance of the essential oil extracted from Sedap Malam flower. Most of the responses were included in categories of “Like” and “Really like”. Additionally, for the fragrance, most of response of the respondents for all the four samples of essential oil were in category of “Really like”.
Investigation of a Steel Local Corrosion in Chloride-Containing Media
Authors: Rumyantseva Varvara , Konovalova Viktoriya
Published: January 2021

Aspects of the development of local corrosion on the metal surface under the influence of aggressive media containing chloride ions are presented. The main mechanisms leading to the formation and development of local damage of the surface of metals are described. The process of electrochemical corrosion of steel under the influence of chloride-containing medium is experimentally investigated. By constructing corrosion diagrams, the main indicators of steel corrosion in a 10% sodium chloride solution were determined, which allows one to judge the rate of development of corrosion processes with local damage to the protective coating and the degree of steel resistance depending on the aggressiveness of the medium. It is shown that protective coatings, such as modified phosphate and oxide-phosphate films, prevent the penetration of an aggressive medium to the surface of the protected metal and, accordingly, the anodic dissolution of the metal.
Rheological Behavior of Self-Compacting Geopolymer Concrete Containing Recycled Aggregates: Effect of Na2SiO3/NaOH and Molarity of NAOH
Authors: Salihi Koran , Younis Khaleel H.
Published: January 2021

To develop a sustainable concrete and to minimize the depletion of the natural resources, an attempt was made to develop sustainable concrete mixtures benefiting from the geopolymer technology and the use of recycled aggregate in self-compacting geopolymer concrete (SCGC). This study aim to examine the effects of sodium hydroxide (SH) molarity and sodium silicate (Na2SiO3)/ sodium hydroxide (SS/SH) ration the fresh properties of SCGC mixtures containing recycled coarse aggregates (RCA) Mixes were prepared with three different molarity (8M, 10M and 12M) of) and four SS/SH ratios (1.5, 2.0, 2.5 and 3.0). Six mixes were examined in this study. The results were compared with the EFNARC limits for self-compacting concrete (SCC). It was found that the SS/SH ratio and the molarity of SH affect the fresh properties of (SCGC). However, the results showed that, SCGC mixtures containing RCA can be developed and satisfy the requirements of EFNARC for fresh state of SCC.