bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of a Frame-Shear Wall Concrete Structure by Using Base Isolation and Evaluation of Structure-Soil Interaction
Authors: Polat H. I.
Published: November 2020

A base isolation system is a type of earthquake-resistant structure design approach based on the principle of reducing a structure’s earthquake response rather than increasing the structure’s earthquake resistance capacity. Seismic base isolated structures have the ability to make large displacements relative to the level of insulation elements. This means that a large structure performs very small displacements between floors during an earthquake and exhibits a rigid body behavior. At this point, the earthquake forces acting on the structure decrease along with the floors. In this article a school building composed of frame-shear wall is resolved primarily with the traditional fixed base structure system, mode shapes are found and periods are obtained. For earthquake response analysis, earthquake loads are distributed to the floors using the equivalent seismic load method and structural elements experiencing capacity problems are found. Then, using the earthquake record, larger failure of cross sections and capacity problems are obtained compared to the first method. In the second stage, the same structure is dissolved again by placing the lead core rubber base isolators between the base and the vertical structural members. The periods of structures under earthquake load have increased significantly by utilizing base isolation, as a result of that spectral accelerations decreased. Thus, large decreases in the shear forces acting to the structure are determined and failures of cross sections are removed.
An Assessment of the Impact of Information Technology on Marketing and Advertising
Authors: Hosseini Z. , Mohammadi S. , Safari H.
Published: November 2020

The present study aimed to evaluate the impact of Technology on Marketing and Advertising by using structural equations modeling. To do this, 200 marketing and information technology (IT) experts participated in the study. They answered questionnaires regarding IT, marketing mix and advertising. For data analysis, structural equations modeling using SMARTPLS were used. The results showed that the effect of IT on marketing mix and advertising was positive and significant. The effect of marketing mix on advertising was positive and significant. The indirect effect of IT on advertising via marketing mix was therefore positive and significant. Totally, the results emphasized the effect of technology on marketing mix and advertising.
Enhancement of Edge-based Image Quality Measures Using Entropy for Histogram Equalization-based Contrast Enhancement Techniques
Authors: Kurmasha H. T. R. , Alharan A. F. H. , Der C. S. , Azami N. H.
Published: November 2020

An Edge-based image quality measure (IQM) technique for the assessment of histogram equalization (HE)-based contrast enhancement techniques has been proposed that outperforms the Absolute Mean Brightness Error (AMBE) and Entropy which are the most commonly used IQMs to evaluate Histogram Equalization based techniques, and also the two prominent fidelity-based IQMs which are Multi-Scale Structural Similarity (MSSIM) and Information Fidelity Criterion-based (IFC) measures. The statistical evaluation results show that the Edge-based IQM, which was designed for detecting noise artifacts distortion, has a Person Correlation Coefficient (PCC) > 0.86 while the others have poor or fair correlation to human opinion, considering the Human Visual Perception (HVP). Based on HVP, this paper propose an enhancement to classic Edge-based IQM by taking into account the brightness saturation distortion which is the most prominent distortion in HE-based contrast enhancement techniques. It is tested and found to have significantly well correlation (PCC > 0.87, Spearman rank order correlation coefficient (SROCC) > 0.92, Root Mean Squared Error (RMSE) < 0.1054, and Outlier Ratio (OR) = 0%).
Design of Multi-Layer Optical Fibers with Ring Refractive Index to Reduce Dispersion and Increase Bandwidth in Broadband Optical Networks
Authors: Seifouri M. , Karkhanehchi M. M. , Rohani S.
Published: November 2020

The main goal in this paper is to design single-mode optical fibers for DWDM networks, which are used today in rapid communications. These networks require low dispersion in a wide range of wavelengths.  So, in this paper, multi-layer optical fibers with low dispersion value and flat dispersion slope in wavelength range of 1.5-1.6µm) are designed, using optimization algorithms.
Study of Water Droplets Behavior on Electrical Machine Insulation Under the Influence of Uniform Electric Fields: the Influence of Some Parameters on Mica Sheets
Authors: Danikas M. , Maslougkas S.
Published: November 2020

Mica sheets are a vital component of electrical machine insulation. Although great attention has been paid to partial discharges and their deteriorating effect on such insulation, relatively little attention has been given to surface discharges. This paper investigates the effect of water droplets, their volume, their conductivity, their positioning as well as their number on the flashover voltage of mica sheets. It is indicated that all the above mentioned parameters influence the flashover voltage
3D Numerical Analysis of the Effects of an Advancing Tunnel on an Existing Loaded Pile Group
Authors: Soomro M. A. , Bangwar D. K. , Soomro M. A. , Keerio M. A.
Published: November 2020

Tunnels are often preferred for underground transportation in densely populated areas. In these areas, it is almost inevitable for tunnels to run close to some existing pile foundations. Since tunnelling activities induce stress relief and soil movement in the ground, existing piles may suffer from additional axial and lateral forces, bending moments, settlements and lateral deflections. Most of the previous researches on the responses of pile foundations due to tunnel construction were carried out under the plane strain condition. In this paper, a three-dimensional, elasto-plastic and coupled-consolidation finite element parametric study has been carried out to investigate the effects of a 6 m open-face advancing tunnel on a two by two pile group in saturated stiff clay. The influence of different cover-to-diameter (C/D) tunnel ratios (namely 2.0, 2.5 & 3.0) was studied. The objectives of this study are to determine the changes in axial load distribution, changes in shaft resistance along the shaft of pile group and settlement of pile cap due to an advancing open-face tunnel.
Security Analysis of Zipper Hash Against Multicollisions Attacks
Authors: Bagheri N.
Published: November 2020

In this paper,  the existence of multicollisions in Zipper Hash structure, a new Hash structure which was introduced to strengthen the iterated Hash structures, is presented. This study shows that finding multicollisions, i.e. 2k-way collision, in this Hash structure is not much harder than finding such  multicollisions in ordinary Merkle  - Damgard (MD)  structure. In fact, the complexity of the attacks is approximately n/2 times harder than what has been found for MD structures. Then, these large multicollisions are used as a tool to find D-way preimage for this structure. The complexity of finding 2K-way multicollisions and 2k-way preimages are  (eq) and (eq) respectively. Similar to what has been proved by Joux for MD, it is shown in this paper that this structure could not be used to create a Hash function with 2n-bit length by concatenating this structure with any other Hash structure by Hash’s output length of n-bite. It is also shown that time complexity of finding a collision for this concatenated structure is (eq)  which is much smaller than what was expected from generic-birthday attack which would be (eq) . In addition, it is shown that increasing the number of rounds of this Hash function can not improve its security against this attack significantly and the attacker can find multicollisions on this Hash function which means that this Hash function has a structural flaw.
A Stable TORA Based for Routing in Mobile Ad Ηoc Networks
Authors: Jahanbakhsh Gudakahriz S. , Jamali S. , Vajed Khiavi M. , Soleimany A.
Published: November 2020

A mobile ad hoc network (MANET) is defined as a set of mobile nodes which communicate through wireless links with no central infrastructure. In these networks nodes are always moving and could enter to or exit from the network at any time. Therefore, network topology is completely dynamic. Another characteristic of these networks is the low node energy level, resulting from inherent node limitations. Stable routing is one method to face routing challenges in mobile ad hoc networks. The objective of this study is to stabilize TORA protocol which is a distributed routing protocol, with high adaptation, efficiency, and suitability for large and dense mobile ad hoc networks and thus to provide a new high efficiency protocol. The proposed protocol introduced as Stable-TORA has been compared with base protocol TORA in different scenarios via NS-2 simulator environment and its efficiency is evaluated.
On Polymers Nanocomposites: Electrical Treeing, Breakdown models and Related Simulations
Authors: Melissinos G. , Danikas M.
Published: November 2020

This paper deals with polymer nanocomposites and their related breakdown mechanisms. Polymer nanocomposites seem to be a very promising alternative to conventional polymers regarding high voltage applications. Some developed breakdown models are discussed as well as the mechanism of treeing in such materials. Treeing simulation results are presented.
Alkali-Aggregate Reaction: A study of the influence of the petrographic characteristics of volcanic rocks
Authors: Tiecher F. , Gomes M. B. , Dal Molin D. C. C.
Published: November 2020

When the rock involved in the alkali-aggregate reaction (AAR) is volcanic, the matter present in the interstices of the grains, called mesostasis is considered responsible for the expansions. Mesostasis is a residue which consists of mineral phases rich in silica and alkalis (K and Na) and in optical microscopy looks like amorphous matter. By means of scanning electron microscopy (SEM) and with the aid of energy dispersive spectroscopy (EDS), the presence of well-crystallized mineral phases in mesostasis can be observed. The objective of this study was to evaluate the amount, the chemical composition and the degree of crystallinity of mesostasis on the reactive potentiality of volcanic rocks.
A Novel Structure for Vector Control of Symmetrical Six-Phase Induction Machines with Three Current Sensors
Authors: Nabi H. P. , Dadashi P. , Shoulaie A.
Published: November 2020

Vector control is one of the most popular multiphase induction machine drive methods due to its dynamic performance. Since all phase currents are needed in vector control drive, by increasing phase numbers, the number of required current sensors increases which is one of the disadvantages of vector control in multiphase machine drives. In this paper vector control of a symmetrical six-phase induction machine with a novel configuration is presented. The aforementioned configuration is designed in a simple way that only three current sensors will be needed. Analytical equations are extracted in this paper to show that some of current components which do not contribute in torque production will be eliminated due to the proposed scheme. Simulation and experimental results are provided to verify the benefits of the proposed configuration.
Modeling a Distributed Power Flow Controller with a PEM Fuel Cell for Power Quality Improvement
Authors: Chakravorty J. , Saraswat J. , Bhatia V.
Published: November 2020

Electrical power demand is increasing at a relatively fast rate over the last years. Because of this increasing demand the power system is becoming very complex. Both electric utilities and end users of electric power are becoming increasingly concerned about power quality. This paper presents a new concept of distributed power flow controller (DPFC), which has been implemented with a proton exchange membrane (PEM) fuel cell. In this paper, a PEM fuel cell has been simulated in Simulink/MATLAB and then has been used in the proposed DPFC model. The new proposed DPFC model has been tested on a IEEE 30 bus system.
MANETS and Internet of Things: The Development of a Data Routing Algorithm
Authors: Alameri I. A.
Published: November 2020

Internet of things (IoT), is an innovative technology which allows the connection of physical things with the digital world through the use of heterogeneous networks and communication technologies. IoT in smart environments interacts with wireless sensor network (WSN) and mobile ad‐hoc network (MANET), becoming even more attractive and economically successful. Interaction between wireless sensor and mobile ad‐hoc networks with the internet of things allows the creation of a new MANET‐IoT systems and IT‐based networks. Such systems give the user greater mobility and reduce costs. At the same time new challenging issues are opened in networking aspects. In this work, author proposed a routing solution for the IoT system using a combination of MANET protocols and WSN routing principles. The presented results of solution's investigation provide an effective approach to efficient energy consumption in the global MANET‐IoT system. That is a step forward to a reliable provision of services over global future internet infrastructure.
Interface Structure and Elements Diffusion of As-Cast and Annealed Ductile Iron/Stainless Steel Bimetal Castings
Authors: Ramadan M.
Published: November 2020

Bimetal casting is considered to a promising technique for the production of high performance function materials. Heat treatment process for bimetal castings became an essential tool for improving interface structure and metallurgical diffusion bond. Molten iron alloy with carbon equivalent of 4.40 is poured into sand mold cavities containing solid 304 stainless steel strips insert. Specimens are heated to 7200C in an electrical heating furnace and holded at 720 0C for 60min and 180min. For as-cast specimens, a good coherent interface structure of ductile cast iron/304 stainless bimetal with four layers interfacial microstructure are obtained. Low temperature annealing at 720oC has a significat effect on the interface layers structure, where, three layers of interface structure are obtained after 180min annealing time because of the complete dissolving of thin layer of ferrite and multi carbides (Layer 2). Low temperature annealing shows a significant effect on the diffusion of C and otherwise shows slightly effect on the diffusion of Cr and Ni. Plearlite phase of Layer 3 is trsformed to spheroidal shape instead of lamallar shape in as-cast bimetals by low tempeature annealing at 720oC. The percent of the performed spheroidal cementit increases by increasing anneaaling time. Hardness of interface layers is changed by low temperauture annealing due to the significant carbon deffussion.
Effect of River Indus Sand on Concrete Tensile Strength
Authors: Lakhiar M. T. , Mohamad N. , Shaikh M. A. B. , Vighio A. A. , Jhatial A. A. , Abdul Samad A. A.
Published: November 2020

In the development of Pakistan construction industry, the utilization of River Indus sand in concrete as fine aggregate has expanded tremendously. The aim of this research is to study the effect of Indus River sand on the tensile strength of various grades of concrete when it is utilized as fine aggregate. Concrete Samples of M15, M20 and M25 grade concrete were cured for 7, 14, 21 and 28 days. Based on the results, it is found that concrete became less workable when Indus river sand was utilized. It is recorded that tensile strength of concrete is decreased from 5% up to 20% in comparison with hill sand. The results were derived from various concrete grades.
Comparison of Mechanical Properties of Lightweight and Normal Weight Concretes Reinforced with Steel Fibers
Authors: Ali A. , Soomro Z. , Iqbal S. , Bhatti N. , Abro A. F.
Published: November 2020

Compared to conventional concrete, lightweight concrete is more brittle in nature however, in many situations its application is advantageous due to its lower weight. The associated brittleness issue can be, to some extent, addressed by incorporation of discrete fibers. It is now established that fibers modify some fresh and hardened concrete properties. However, evaluation of those properties for lightweight fiber-reinforced concrete (LWFC) against conventional/normal weight concrete of similar strength class has not been done before. Current study not only discusses the change in these properties for lightweight concrete after the addition of steel fibers, but also presents a comparison of these properties with conventional concrete with and without fibers. Both the lightweight and conventional concrete were reinforced with similar types and quantity of fibers. Hooked end steel fibers were added in the quantities of 0, 20, 40 and 60kg/m3. For similar compressive strength class, results indicate that compared to normal weight fiber-reinforced concrete (NWFC), lightweight fiber-reinforced concrete (LWFC) has better fresh concrete properties, but performs poorly when tested for hardened concrete properties.
Mobile Phone Brand Categorization vs. Users' Security Practices
Authors: Androulidakis I. , Kandus G.
Published: November 2020

In the present paper, we correlated the brand of mobile phone to users’ security practices, statistically processing a large pool of the responses of 7172 students in 17 Universities of 10 Eastern and Southern Europe countries. Users show different behavior in an array of characteristics, according to the brand of the mobile phone they are using. As such, there is a categorization of areas, different for each brand, where users are clearly lacking security mind, possibly due to lack of awareness. Such a categorization can help phone manufacturers enhance their mobile phones in regards to security, preferably transparently for the user.
Block Milne’s Implementation For Solving Fourth Order Ordinary Differential Equations
Authors: Oghonyon J. G. , Okunuga S. A. , Eke K. S. , Odetunmibi O. A.
Published: November 2020

Block predictor-corrector method for solving non-stiff ordinary differential equations (ODEs) started with Milne’s device. Milne’s device is an extension of the block predictor-corrector method providing further benefits and better results. This study considers Milne’s devise for solving fourth order ODEs. A combination of Newton’s backward difference interpolation polynomial and numerical integration method are applied and integrated at some selected grid points to formulate the block predictor-corrector method. Moreover, Milne’s devise advances the computational efficiency by applying the principal local truncation error (PLTE) of the block predictor-corrector method after establishing the order. The numerical results were exhibited to attest the functioning of Milne’s devise in solving fourth order ODEs. The complete results were obtained with the aid of Mathematica 9 kernel for Microsoft Windows. Numerical results showcase that Milne’s device is more effective than existent methods in terms of design new step size, determining the convergence criteria and maximizing errors at all examined convergence levels.
Experimental Evaluation of a Flat Plate Solar Collector Under Hail City Climate
Authors: Ben Khedher N.
Published: November 2020

Flat plate solar water heaters are widely used for water heating in low-temperature residential applications. In this paper the thermal performance of a solar flat plate water heater under Hail weather conditions (latitude 27°52΄N longitude ‎41°69΄E) was experimentally investigated. Fluid was circulated through the imbedded copper tubes in the flat plate collector and inlet and outlet temperatures of the fluid were noted at five minute intervals. The experimental-time was between 9:00AM-15:00PM. A study was carried out experimentally to present the efficiency curves of a flat plate solar collector at different flow rates. ASHRAE standard 93-2003 was followed for calculation of instantaneous efficiency of solar collector. Result shows that the flow rate of the circulating fluid highly influence the thermal efficiency of the solar collector. Optimum flow rate of 2.5L/min leads to maximum collector efficiency.
Synthesis and Mechanical Characterization of High Density Polyethylene/Graphene Nanocomposites
Authors: Alghamdi A. S.
Published: November 2020

The purpose of this work is to investigate the effects of graphene nanosheets (GNSs) addition on the mechanical and thermal properties of high density polyethylene (HDPE). The HDPE/Graphene nanocomposites were synthesized using solution blending approach. HDPE was incorporated with graphene nanosheets in a solvent at various weights of fractions (0.1, 0.2, 0.4 and 0.5 wt%), and then the micro-hardness, elastic modulus, tensile strength, strain at break and thermal properties of the nanocomposites were measured and compared. The results showed that the use of Xylene solvent at high temperature combined with mechanical stirring can fully dissolve HDPE pellets. Scanning electron microscope (SEM) showed that GNSs were homogenously dispersed in the polyethylene matrix at low weights of fractions. The addition of just 0.2 wt% GNSs resulted in 100% increase in the micro-hardness value. The elastic modulus and tensile strength properties are proportionally increased with increasing GNSs content up to 0.4 wt%. However, at higher weight of fraction, a reduction in these properties is observed. The crystallinity and strain at break properties are reduced with the addition of GNSs.
ANN and ANFIS for Short Term Load Forecasting
Authors: Chakravorty J. , Shah S. , Nagraja H. N.
Published: November 2020

Load forecasting has become one of the major areas of research in electrical engineering. Short term load forecasting (STLF) is essential for power system planning and economic load dispatch. A variety of mathematical methods has been developed for load forecasting. This paper discusses the influencing factors of STLF and an artificial intelligence (AI) based STLF model for MGVCL load. It also includes comparison of various AI models. Our main objective is to develop the best suited model for MGVCL, by critically evaluating the ways in which the AI techniques proposed are designed and tested.
Precise Generators Synchronization a Small HPP with an Excitation System
Authors: Tsolov A.
Published: November 2020

The main problem in the process of synchronization of small synchronous generators in HPPs is the maintenance of a constant difference in the angular velocities of the generator and the system (sliding). This is necessary for the correct operation of any automatic accurate synchronization algorithm. This article proposes a method based on the combined action of the excitation system and the speed regulator of synchronous generators. The results provide a basis for the practical implementation of the proposed algorithm relevant for mathematical and physical research.
Effect of Time, Solvent-Solid Ratio, Ethanol Concentration and Temperature on Extraction Yield of Phenolic Compounds From Olive Leaves
Authors: Elboughdiri N.
Published: November 2020

This study aims to determine the factors affecting the process of extraction of phenolic compounds from olive leaves. Two methods of extraction were used in this work and different tests were implemented with the aim of optimizing the recovery of phenolic compounds from olive leaves. The factors considered were the extraction time, temperature, solvent-solid ratio and the ethanol concentration. Obtained results show that the recommended optimal conditions for the extraction of the total phenolic compounds from olive leaves were found at 40°C with a solvent/solid ratio of 30:1 and ethanol concentration of 80% (v/v) when the dried olive leaves are stored at -21°C at the beginning of the experiments.
Effect of Maximum Aggregate Size on the Bond Strength of Reinforcements in Concrete
Authors: Iqbal S. , Ullah N. , Ali A.
Published: November 2020

The bond between reinforcements and concrete is the only mechanism that transfers the tensile stresses from concrete to reinforcements. Several factors including chemical adhesion, roughness and reinforcement interface and bar bearing affect the bond strength of reinforcements with concrete. This work was carried out considering another varying factor which is maximum aggregate size. Four mixes of concrete with similar compressive strengths but different maximum aggregate sizes of 25.4mm, 19.05mm, 12.7mm and 9.53mm were used with the same bar size of 16mm. Compressive strength, splitting tensile strength and bond strength for each concrete mix were studied. Test results depict a slight increase in compressive and splitting tensile strength with decrease in maximum aggregate size. The bond strength remained at the same level with decrease in maximum aggregate size except at maximum aggregate size of 9.53mm when there was a drop in bond strength, despite better compressive and splitting tensile strengths. ACI-318 and FIB-2010 codes equation for bond strength calculation work well only when the maximum aggregate size is 12.7mm and above. Therefore, maximum aggregate size is critical for bond strength when smaller size aggregates are used.
Using Association Rules to Enrich Arabic Ontology
Authors: Ksiksi A. , Amiri H.
Published: November 2020

In this article, we propose the use of a minimal generic base of associative rules between term association rules, to automatically enrich an existing domain ontology. Initially, non-redundant association rules between terms are extracted from an Arabic corpus. Then, the matching of the candidate terms is done through the matching between the concepts of the initial ontology and the premises of the association rules, with three distance measures that we define.
Process Capability and Average Roughness in Abrasive Water Jet Cutting Process of Stainless Steel
Authors: Boujelbene M.
Published: November 2020

Process capability analysis is frequently employed to evaluate if a product or a process can meet the customer’s requirement. In general, process capability analysis can be represented by using the process capability index. Until now, the process capability index was frequently used for manufacturing processes with quantitative characteristics. However, for a process with qualitative characteristic like cutting surface, the data’s type and single specification caused limitations of using the process capability index. Taguchi developed a surface quality by abrasive water jet cutting or quadratic quality loss function to address such issues. In this study, we intend to construct a measurable index which incorporates the process capability index philosophy concept to analyze the process capability with the consideration of the qualitative surface roughness. The manufacturers can employ the proposed index to self-assess the process capability. The objective of this study was to examine the effects of abrasive water jet machining variables like cutting speed of the stainless steel material. The roughness of the varied surface through the cut depth was also measured and determined as a process capability index of 3 zones machined surface.
Flexural Performance of Concrete Reinforced by Plastic Fibers
Authors: Lakhiar M. T. , Sohu S. , Bhatti I. A. , Bhatti N. , Abbasi S. A. , Tarique M.
Published: November 2020

For sustainable development construction, recycle or reuse of waste materials is utilized. Many researchers conducted tried to create an innovative green concrete, utilizing waste materials. The aim of this research is to contribute and promote the use of plastic waste in concrete. The concrete’s flexural and workability were investigated by using different percentages of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1% of plastic fibers in concrete. In this study, M15 grade concrete beams were casted and cured for 7 and 28 days to analyze the flexural performance and workability. The outcomes demonstrated that the workability was slightly reduced by the utilizing plastic fibers where flexural strength improved by 16.5% at 0.6% addition of plastic fibers in concrete.
Using Wave Equation to Extract Digital Signal Features
Authors: Al-Rawashdeh A. Y. , Al-Qadi Z.
Published: November 2020

Voice signals are one of the most popular data types. They are used in various applications like security systems. In the current study a method based on wave equation was proposed, implemented and tested. This method was used for correct feature array generation. The feature array can be used as a key to identify the voice signal without any dependence on the voice signal type or size. Results indicated that the proposed method can produce a unique feature array for each voice signal. They also showed that the proposed method can be faster than other feature extraction methods.
Effect of Single Oxide Fluxes on Morphology and Mechanical Properties of ATIG on 316 L Austenitic Stainless Steel Welds
Authors: Hdhibi A. , Touileb K. , Djoudjou R. , Ouis A. , Bouazizi M. L. , Chakhari J.
Published: November 2020

Tungsten inert gas (TIG) is a wide common process used in fabrication due to its low cost equipment, high quality and accuracy welds but has low productivity related to the low penetration depth in single pass. A new perspective, the Activated Tungsten Inert Gas (ATIG), in which the same equipment as TIG is used, except that a thin layer of activated flux is deposited on a workpiece surface. In this work, eight kinds of oxides were tested on 316L austenitic stainless steel. Three levels of welding current were used to study the effect of different activating fluxes on weld bead geometry and mechanical properties. X-ray Photoelectron Spectroscopy (XPS) was used for the first and the second level energy for different ATIG welds to analyze the relationship between the weld shape and oxygen content in welds. The experimental results showed that the weld profile is related to the thermodynamic stability of selected oxides and in relation to the energy provided. ATIG with TiO2, SiO2, MnO2 oxides presented the deepest welds followed by Cr2O3, Fe2O3, and ZnO. Finally ZrO2, CaO oxides had no effect on the weld depth. The ATIG welded joint showed better tensile strength than TIG. The ATIG hardness measurements carried out showed also better if not the same as TIG weld except for the Silicon oxide weld. Results of the impact test showed that, except for the titanium dioxide TiO2 which has a good benefit, the weldment using the other oxide fluxes exhibits worse withstanding to sudden shock than TIG welding.
Performance Analysis of Water Filtration Units for Reduction of pH, Turbidity, Solids and Electricity Conductivity
Authors: Laghari A. N. , Walasai G. D. , Jatoi A. R. , Shaikh F. A. , Siyal Z. A.
Published: November 2020

The main objective of this study was to analyze the performance of different filtration units that reduce turbidity, pH, total dissolved solids (TDS) and electrical conductivity (EC) of canal water. For that, three different types of filtration units, namely, slow sand, rapid sand and dual media were fabricated. Typical parameters of canal and filtered water, like pH, turbidity, TDS and EC were examined, and then the filtered water quality was compared with World Health Organizations (WHO) standards. Maximum pH reduction was noted with dual media and less by the rapid system, while more turbidity was reduced with the slow sand and less with the dual media filtration system. In contrary to the pH and turbidity results, increment in both TDS and EC values were noted in filtered samples compared to that of raw water samples due to the transfer of dissolved minerals present in the sand into the filtered water during the contact period with media in the bed. However, all examined parameters of filtered water were within WHO standards.
Aging Time Effects on the Mechanical Properties of Al 6061-T6 Alloy
Authors: Rajaa S. M. , Abdulhadi H. A. , Jabur K. S. , Mohammed G. R.
Published: November 2020

This work investigates the influence of artificial aging and solution heat treatment on the hardness and tensile strength (mechanical properties) of Al 6061-T6 alloy. For this investigation, several aluminum 6061-T6 alloy specimens were prepared following the ASTM 176000 recommendations. The prepared specimens were heated for 1 hour at 500ºC before being water-quenched. The procedure for artificial aging was performed for 1, 2, 3, and 4 hours at 190ºC before being slowly cooled in air. Several mechanical and characterization studies were performed on the treated specimens, including an investigation on their microstructure, tensile strength, hardness, and X-ray diffraction pattern. From the results, the strength and hardness properties of the specimens were found to be generally improved, even as the best features were obtained after 2 hours of artificial aging.
Event Based Clustering Localized Energy Efficient Ant Colony Optimization (EBC_LEE-ACO) for Performance Enhancement of Wireless Sensor Network
Authors: Chavan S. D. , Kulkarni A. V.
Published: November 2020

The main challenge of a wireless sensor network (WSN) in disaster situations is to discover efficient routing, to improve quality of service (QoS) and to reduce energy consumption. Location awareness of nodes is also useful or even necessary. Without knowing the position of sensor nodes, collected data is insignificant. Ant colony optimization (ACO) is a unique form of optimization method, which is highly suitable for adaptive routing and guaranteed packet delivery. The primary drawbacks of ACO are data flooding, huge overhead of control messages and long convergence time. These drawbacks are overcome by considering location information of sensor nodes. An event-based clustering localized energy efficient ant colony optimization (EBC_LEE-ACO) algorithm is proposed to enhance the performance of WSN. The main focus of the proposed algorithm is to improve QoS and minimize the network energy consumption by cluster formation and selecting the optimal path based on the biological inspired routing-ACO and location information of nodes. In clustering, data is aggregated and sent to the sink (base station) through cluster head (CH) which reduces overheads. EBC_LEE-ACO is a scalable and energy efficient reactive routing algorithm which improves QoS, lifetime and minimizes energy consummation of WSN as compared to other routing algorithms like AODV, ACO, ACO using RSSI. The proposed algorithm reduces energy consumption by approximately 7%, in addition to improvement in throughput, packet delivery ratio and increase in packet drop which has been observed in comparison with other algorithms, i.e. autonomous localization based eligible energetic Path_with_Ant Colony optimization (ALEEP with ACO) of the network. Use of IEEE 802.11 standard in proposed work increased packet drop.
Industrial Bearing Fault Detection Using Time-Frequency Analysis
Authors: Bella Y. , Oulmane A. , Mostefai M.
Published: November 2020

Time-frequency fault detection techniques were applied in this study, for monitoring real life industrial bearing. For this aim, an experimental test bench was developed to emulate the bearing rotating motion and to measure the induced vibration signals. Dedicated software was used to analyze the acquired measurements in the time-frequency domain using several distributions with varying resolution. Results showed that each fault type exhibits a specific behavior in the time-frequency domain, which is exploited in the localization of the faulty component.
Delignification of Rice Husk by Microwave Assisted Chemical Pretreatment
Authors: Laghari S. M. , Tunio M. M. , Laghari A. Q. , Laghari A. J. , Ali A. M.
Published: November 2020

Rice husk has the potential to be used as a source of alternative energy e.g. as biofuel. Its high lignin content, however, poses difficulty to this use. This study investigates the use of microwave assisted acidic and alkaline pretreatment methods to improve the characteristics of rice husk for energy production. The use of microwave assisted 3.5% NaOH provided optimum pretreatment of rice husk; the lignin content was reduced from 17.8 to 10.2%, the cellulose content increased from 38.6 to 59.3% and the C/N ratio was within the optimum range of 25-35. The results showed enhanced potential of biofuel production from rice husk by this pretreatment.
An IoT Based Real-Time Environmental Monitoring System Using Arduino and Cloud Service
Authors: Zafar S. , Miraj G. , Baloch R. , Murtaza D. , Arshad K.
Published: November 2020

Internet of Things (IoT) is expected to play a major role in our lives through pervasive systems of sensor networks encompassing our environment. These systems are designed to monitor vital physical phenomena generating data which can be transmitted and saved at cloud from where this information can be accessed through applications and further actions can be taken. This paper presents the implementation and results of an environmental monitoring system which employs sensors for temperature and humidity of the surrounding area. This data can be used to trigger short term actions such as remotely controlling heating or cooling devices or long term statistics. The sensed data is uploaded to cloud storage and an Android application accesses the cloud and presents the results to the end users. The system employs Arduino UNO board, DHT11 sensor, ESP8266 Wi-Fi module, which transmits data to open IoT API service ThingSpeak where it is analyzed and stored. An Android application is developed which accesses the cloud and displays results for end users via REST API Web service. The experimental results show the usefulness of the system.
Uterine EMG Signals Spectral Analysis for Pre-Term Birth Prediction
Authors: Tsipouras M. G.
Published: November 2020

A methodology for prediction of pre-term births is presented in this paper. The methodology is based on the analysis of EHG signals and data mining techniques. Initially, spectral and non-linear characteristics of the EHG are extracted, forming a pattern that is used to train a classifier to discriminate between term and pre-term cases. The method has been tested using a benchmark EHG database, and the obtained results indicate its effectiveness in accurate pre-term/term labour prediction.
Web Information System for the Governance of University Research
Authors: Benmoussa K. , Khoulji S. , Laaziri M. , Larbi K. M.
Published: November 2020

Technology development has proved crucial in analyzing and processing the volume of scientific information that is generated today. Governments are developing scientific and technical information systems that, beyond a database, are a real tool for supporting research management and decision-making in the field of science and technology policy. For the development of higher education in Morocco, the ministry has focused on projects for the management and development of university research. For this purpose, Abdelmalek Essaadi University developed an efficient application dedicated to the management of collaborative extranet called SIMarech (Moroccan Information System of Scientific Research), in order to support, organize and structure all academic activities. It will enable all university stakeholders to use a digital workspace specific to their roles, to access and share information, and interact and engage in national scientific research. This article presents an overview of research management systems and the design and development of SIMarech, which is designed as a tool for monitoring research conducted by a university or other institutions.
Risk Attributes, Influencing the Time and Cost Overrun in Joint Venture Construction Projects of Pakistan
Authors: Akhund M. A. , Khoso A. R. , Pathan A. A. , Imad H. U. , Siddiqui F.
Published: November 2020

Business collaborations formed by construction contractors to enhance their abilities and effectiveness in large construction projects are known as construction joint ventures (CJVs). It is widely used as a way of merging assets, capitals, funds, resources and expertise of different organizations. It helps business to grow faster, increase efficiency and generate greater profits without borrowing money. Though it is useful and beneficent for the vendors, it may contain several types of risk. It is both beneficial and stimulating due to differing technical skills, economic and political atmospheres, and cultural and legal backgrounds. Recent development and modernization in Pakistan have led it towards a new construction phase, which involves national and multinational joint venture projects. Global and local CJVs have become gradually prevalent to produce mega construction projects. Current research aims to investigate and to identify the communal, ecological, political, legal, economic and other external risks associated with CJV projects in Pakistan. The study was carried out by literature review and a few national and international guidelines. Interviews were conducted with relevant professionals, experts, and owners of the organizations working on CJV projects. Data was collected in the form of a questionnaire from relevant professionals. The descriptive analysis was performed through SPSS using average index (A.I) technique. This study is helpful for the Government of Pakistan, public and private construction firms working under JV to reduce the emerging risks of construction projects.
Frequency Speed Control of Rotary Travelling Wave Ultrasonic Motor Using Fuzzy Controller
Authors: Kebbab F. Z. , Belkhiat D. E. C. , Jabri D. , Belkhiat S.
Published: November 2020

This paper proposes frequency speed control of rotary travelling wave ultrasonic motor (TWUSM), type Daimler Benz AWM90-X motor. The control characteristics of TWUSM are complicated, highly nonlinear and varying in time. This can lead to deterioration of the performance of conventional controller such as proportional integral (PI). In order to achieve high control performance of the TWUSM, fuzzy logic controller (FLC) has been designed and compared to the conventional PI controller. To validate the performance of the proposed FLC, simulation of the speed response has been performed and analyzed for a varying load. The simulation results show that the FLC has smaller settling time, smaller rising time and minimum error in steady state. Furthermore, the fuzzy controller provides good results for large load variations. The frequency output of the controller has been validated with experimental measurements of AWM90-X.
Performance Analysis of OFDM and OFDM-MIMO Systems under Fading Channels
Authors: Elsanousi A. , Oztürk S.
Published: November 2020

Fourth-generation (4G) wireless communication system is mainly based on MIMO (multiple input and multiple output) and OFDM (orthogonal frequency division multiplexing). The combination of these two techniques leads to a better system, known as OFDM-MIMO system, providing higher capacity and data rate. This paper demonstrates the BER (bit error rate) performance of OFDM and OFDM-MIMO system using convolution code to encrypt the data stream that can be sent over communication channels. Simulation is made on Matlab using three different channels (AWGN, Rician and Rayleigh). The simulation results show that the combined system has better performance compared to OFDM system. The practical part of this study was conducted by using two USRPs B210 (universal software radio peripheral) for transmitting and receiving, two antennas were used during transmission for both sides. The transmitted signal is successfully recovered.
Analysis of Device-to-Device Communication over Double-Generalized Gamma Channels
Authors: Hussain Z. , Khan A. ur R. , Mehdi H. , Saleem S. M. A.
Published: November 2020

In this paper, performance of a device-to-device (D2D) communication system is analyzed over double-generalized Gamma (dGG) fading channels. The dGG is a generic distribution for modeling double-scattering fading conditions. Co-channel interference (CCI) caused by various wireless devices in the system is also considered. The CCI fading channel is assumed to be Nakagami distributed. Analytical expressions for important statistical metrics, i.e. probability density function (PDF) and cumulative distribution function (CDF) of signal-to-interference ratio (SIR), are presented. Based on these statistical parameters, expressions for the outage probability, channel capacity and symbol error rate (SER) of the D2D communication system are presented. The performance of D2D system is then discussed and analyzed with the help of numerical results with arbitrary channel fading, path-loss and interference conditions.
Synthesis and Characterization of Poly(styrene)-block-Poly(acrylic acid) and Organoclay Based Hybrid Composite Materials
Authors: Soomro S. H. , Sanaullah M. , Zaman N. , Laghari A. Q. , Jalbani N. B. , Mirza K. , Abbasi E. A.
Published: November 2020

Abstract—Polystyrene (PS) and polyacrylic acid (PAA) are organic and synthetic polymers. Generally, a composite needs a matrix and reinforcement. Montmorillonite (MMT) is used as reinforcement to form a hybrid matrix by ultra-sonication. Block polymers of PS and PAA were first synthesized and then hybrid nanocomposite material of synthesized block polymeric matrix was fabricated by incorporating organoclay as reinforcement through 6 and 12 hours of ultra-sonication. The characterizations of the hybrid nanocomposite material were done by UV-visible and infrared (IR) spectroscopy, which confirm the successful synthesis of PS and PAA block polymer. The UV-visible spectroscopic measurements revealed that hybrid composite material is different from PS-block-PAA and that absorbance increases on increasing concentration. After successful ultra-sonication the hybrid composite is analyzed through scan electron microscopy (SEM) regarding surface morphology, distribution, uniformity, porosity, matrix compatibility, and matrix reinforcements. Sonication (for 6 hours) demonstrates a heterogeneous porous surface and an increase in roughness and porosity of surface morphology at different optical zooms.
Contributing Factors of Time Overrun in Public Sector Construction Projects
Authors: Akhund M. A. , Imad H. U. , Memon N. A. , Siddiqui F. , Khoso A. R. , Panhwar A. A.
Published: November 2020

Time overrun is a major issue in construction projects. Its causes vary, depending upon the nature and size of the project. Developing countries are more susceptible to this problem due to limited resources and lack of managerial skills. This paper focuses on the identification and classification of time overrun factors in public sector projects in Pakistan. Data was collected by the use of a questionnaire given to different professionals in the construction field. Average index (AI) was used to determine each factor’s relative importance. Results indicate that financial difficulties faced by constructor, inadequate planning and scheduling, financial difficulties faced by client, delays in payment by the client, delays in decision making by the client, design mistakes, frequent design changes, material shortage, incompetent sub-constructor assigned by the constructor, poor site management and supervision and inadequate constructor’s experience are the most significant factors of time overrun in public sector construction projects in Pakistan. This study aims to be useful in addressing the issue of time overrun in the construction industry.