bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Power Flow Capacity of Transmission Lines Using DPFC with a PEM Fuel Cell
Authors: Chakravorty J. , Saraswat J.
Published: November 2020

The electrical power system is one complex architecture integrating generation, transmission, distribution, and utilization sections. The exponential increase in power requirements made this system more complex and dynamic. Providing good quality and uninterrupted power has become a challenge. In this respect, FACTS devices are playing a vital role in improving power quality and also in increasing the transmission capacity of lines. In this paper. Distributed Power Flow Controller (DPFC), with a PEM fuel cell, has been used in an IEEE-14 bus system to improve system power flow capacity. The proposed IEEE-14 bus with DPFC has been simulated in MATLAB/SIMULINK. The effects are exhibited and analyzed.
Network Reconfiguration for an Electric Distribution System with Distributed Generators based on Symbiotic Organisms Search
Authors: Duong T. L. , Nguyen T. T.
Published: November 2020

This paper proposes a method of network reconfiguration based on symbiotic organisms search (SOS) algorithm for reducing power loss of the electric distribution system. The SOS is a recent developed meta-heuristic algorithm inspired from the symbiotic interaction strategies of organisms for surviving and propagating in the ecosystem. Compared to other algorithms, SOS does not need any control parameters during the searching process. The advantages of the proposed SOS method have been validated in two electric distribution systems. Three network cases have been considered for each system, consisting of performing network reconfiguration on the system without distributed generator (DG) placement, the system installed type-P DGs and the system installed type-PQ DGs. The comparison results with particle swarm optimization and other previous methods show that the proposed SOS can be a promising technique for the problem of electric network reconfiguration.
Current-mode CMOS Active Inductor with Applications to Low-Voltage Oscillators
Authors: Ma M. , Li Z. , Yao Z.
Published: November 2020

This paper investigates a current mode active inductor. In the proposed active inductor, three current mirrors have been connected to each other to realize the negative feedback. This active conductor has a two layer transistor structure. A 4.257 GHz, 1.2-V power supply non-inductive LC negative resistor oscillator, base on two of the proposed active inductors, is demonstrated.
Rotor Angle and Voltage Stability Analysis with Fault Location Identification on the IEEE 9 Bus System
Authors: Khan H. F. , Hanif A. H. , Anwar N.
Published: November 2020

Transient stability is very imperative in multi-machine interconnected power systems in order to scrutinize and analyze the system’s performance and response. Rotor angle stability and voltage stability are studied in this paper. By applying three-phase symmetrical faults, the transient stability of the IEEE 9 bus system is studied. A characteristic double hump is analyzed in the response of the generator, which is nearer to the fault location. By analyzing the characteristic double hump, the fault location in a large interconnected power system can be determined. It is shown that, as the fault is cleared, the system takes some finite time to return to its prior state. IEEE 9 bus system is chosen as a test system, which standard parameters. MATLAB Simpower System toolbox is used for load flow and transient stability analysis.
Numerical Simulations on Mixing Dynamics of Spherical and Non-Spherical Tablets in a Pan Coater
Authors: Chand R. , Hadj Lajimi R. , Uddin S. , Meghwar S. , Farooq U. , Rekik N.
Published: November 2020

Discrete element simulations provide valuable insight into the mixing dynamics of granular materials in industry. In this paper, numerical work is conducted in order to find the influence of pan rotational velocity and particle shape on mixing behavior. Four types of particles of different shapes were chosen: spherical, non-spherical type 1 (disk shape), non-spherical type 2 (capsule shape), and non-spherical type 3 (triangular shape). The pan mixer was filled with ~ 30 % volume of the same shape with the particles and was rotated at 15 RPM, 30 RPM, 45 RPM, and 60 RPM. The particles were colored as bottom-particles, middle-particles, and top-particles in order to visualize mixing efficiency. The homogeneity of the mixtures was determined by using contact dynamics of particles. The results show that fast-rotating pan (30-60 RPM) provides good mixing for all shapes of particles. However, non-spherical particles do not show as good mixing as spherical particles.
Parametric Analysis of an Embankment Dam’s Stability
Authors: Bhutto A. H. , Zardari S. , Bhurgri G. S. , Zardari M. A. , Bhanbhro R. , Babar M. M. , Memon B. A.
Published: November 2020

This paper presents a stability parametric analysis of a 59m high embankment dam. The analysis was performed in order to evaluate the minimum values of strength parameters that satisfy the stability requirements of the dam. The parametric analysis was conducted for three main zones of the dam: upstream shell, core, and downstream shell, which consisted of sandy gravel, clay, and random fill respectively. The friction angles of these materials were gradually decreased in order to represent different soil conditions. It was observed that stability requirements for the end of construction and after the filling of the reservoir could be satisfied if friction angle values of the sandy gravel and the random fill are 34º and 32º, instead of 37º and 34º. However, the value of the core’s cohesion could be utilized as 30º without any reduction so that the dam could be safe after the filling of the reservoir. The results of this study could be beneficial to practicing engineers for the design of safe and economical embankment dams.
Investigation of an Insulator Flashunder in an 150 kV OTL of the Power System of Crete
Authors: Pylarinos D. , Pellas I.
Published: November 2020

Overhead Transmission Lines (OTLs) are used in Power Systems to carry High Voltage between substations, usually over long distances. Faults in OTLs are bound to happen and thus locating and coping with them is an important aspect of OTL’s operation and maintenance. These faults may be of temporary or permanent nature, with certain types of faults progressing over time from the first category to the second. Local weather may also have a direct effect on the occurrence of faults resulting to puzzling events. A special category, often complex in nature, is insulator faults. Insulators are used in OTLs to support phase conductors while not allowing current to flow through the tower’s body to the ground. Traditional ceramic insulators used materials such as porcelain and glass as insulation, but in the last decades composite insulators with two insulating parts (a glass core/rod and a rubber housing), have also known great use mainly due to their low weight and their capability to withstand pollution. However, they are subjected to certain faults unique to them, such as flashunders. Flashunder is a term commonly used lately to describe faults that are related to the rod/housing interface of composite insulators. Such faults are rather difficult to locate as the electrical discharge does not create an easily visible trace (as in the case of flashovers) or a permanent mechanical fault (as in the case of brittle fractures). Such a fault occurred for the first time in the Transmission System of Crete in 2019 and this paper follows and discusses the incident and the experience gained.
The Impact of Digital Transformation on Business Performance: A Study of Pakistani SMEs
Authors: Mubarak M. F. , Shaikh F. A. , Mubarik M. , Samo K. A. , Mastoi S.
Published: November 2020

Business ecosystems are continuously evolving. In this hyper-competitive era, firms are increasingly transforming their business operations through advanced digital technologies. Gone are the days of mere testing and debating the influence of digital transformation and industry 4.0, yet the time has come for actionable steps. Therefore, this study has identified the role of industry 4.0 technologies including big data, cyber-physical systems, internet of things and interoperability, on the performance of Small and Medium-sized Enterprises (SMEs) in Pakistan. A relevant questionnaire was developed and distributed randomly in the cities of Karachi, Lahore, Peshawar, Islamabad, Gujrat, and Sialkot. After applying multiple regression techniques through SPSS, it was found that big data, cyber-physical systems, and interoperability have a significant positive impact to improve business performance, while the insignificant effect of internet of things was revealed. Since the research in the area of digital transformation and industry 4.0 is scant, the current study has contributed novel directions, insights and a framework for future researchers. Moreover, this study will help managers to justify the allocation of resources towards technological infrastructure development in the operations of their firms. Finally, policymakers will find it helpful in order to devise suitable strategies for developing human capital and to enhance their absorptive capacity.
A Comparative Study of 316L Stainless Steel and a Titanium Alloy in an Aggressive Biological Medium
Authors: Aroussi D. , Aour B. , Bouaziz A. S.
Published: November 2020

The electrochemical behavior of stainless steel and titanium alloys is affected after prolonged contact with basic or acidic solutions, indicating a change in their surface properties. The human body often rejects invasive devices that aim to alter the biological or chemical composition of blood or other body fluids. Stents, fixation plates and screws, spinal implant devices, aneurysm clips, intramedullary nails and stems, temporary fixation devices and surgical instruments, etc. have been made from stainless steel AISI 316L for several years. Although the mechanical performance of implants and devices may be governed by their bulk properties, their interaction with the environment is managed by the characteristics of their superficial layer. In the case of biomedical devices, resistance to corrosion and biocompatibility has paramount importance. This study compares the corrosion behavior of 316L stainless steel and a titanium alloy in a Hank solution. The obtained results show that the titanium alloy has a higher potential than 316L stainless steel and lower corrosion current.
Numerical Analysis of Rapid Drawdown of an Embankment Dam
Authors: Bhutto A. H. , Bhurgri G. S. , Zardari S. , Zardari M. A. , Bhanbhro R. , Memon B. A.
Published: November 2020

Numerical analysis for the safe rate determination of lowering of an embankment dam was performed in this study with the use of the finite element method. Coupled deformation and consolidation analysis were carried out for staged construction and drawdown of a 59m embankment dam for varying undrained shear strength of the clay core. The lowering of the reservoir was performed at different depths between two extreme scenarios, i.e. rapid lowering rate (1m/day) and slow lowering rate (0.1m/day). The reservoir of the dam was lowered to a depth from 10m to 55m in gradual increments. The results indicated that the safety of the dam was satisfactory when the reservoir was lowered at the quick rate for a depth of 10m, 20m, 30m respectively when the undrained shear strength of the clay core was taken as 20, 25 and 30kN/m2. Regarding the case of slow drawdown rate of the reservoir, it was found that the reservoir could be lowered up to a depth of 55m at a rate of 0.1m/day when the undrained strength of clay core was 25kN/m2. The stability of the dam was also found satisfactory even though the reservoir was lowered at a rate of 0.25m/day for a depth of 55m when the undrained shear strength of clay core was 30kN/m2.
A Review on Secure Group Key Management Schemes for Data Gathering in Wireless Sensor Networks
Authors: Apsara M. B. , Dayananda P. , Sowmyarani C. N.
Published: November 2020

Wireless Sensor Networks (WSNs) is a fast-emerging technology which has become an integral part of the research. WSNs have various applications covering military, environment monitoring, health care, surveillance, national security, etc. Due to the inherent nature of wireless communication, such types of networks are more vulnerable to security attacks, and the authentication and confidentiality of wireless networks are much more critical. WSNs needs include efficient clustering methods, data aggregation methods, data compression methods, data encryption and authentication methods, and data gathering methods. WSNs are more vulnerable to attacks due to their ad hoc nature, so the design of a good key management scheme to provide security is necessary. In this paper, different methods of clustering, data aggregation, data compression, data encryption and authentication, and data gathering are analyzed. A survey is conducted on the key management schemes of WSNs.
Experimental Study of the Lateral Spreading Pressure Acting on a Pile Foundation During Earthquakes
Authors: Nagao T. , Shibata D.
Published: November 2020

In the seismic design of pile foundations, the safety of the pile is assessed by considering the inertial force during an earthquake and subgrade reaction as external forces against the pile. The amount of deformation of the pile must be limited to a small value to maintain the safety of the pile. In the event of a large earthquake, quay walls and seawalls are subjected to lateral spreading because of the influence of biased seaward earth pressure. The amount of lateral spreading is considerably larger than what can be expected in a typical pile seismic design and may reach several meters. In this study, loading experiments that reproduced lateral spreading were conducted to evaluate the lateral spreading pressure acting on a pile when considerably large lateral spreading occurred. The experiment results showed that lateral spreading pressure depended on the ratio of pile spacing to pile diameter while the peak value of lateral spreading pressure was larger than the one assumed in practical design.
Impact of Right Bank Outfall Drain-I (RBOD-I) / Main Nara Valley Drain (MNVD) on Manchar Lake, Sindh, Pakistan
Authors: Mahessar A. A. , Ansari K. , Arain G. M. , Kori S. M. , Qureshi S. , Qureshi A. L.
Published: November 2020

The lakes of Sindh are in poor environmental condition due to the massive disposal of effluents. This paper presents the impact of water quality in Manchar Lake due to climate change and anthropogenic intervention. The lake is one of the biggest natural lakes in Sindh, Pakistan. The lake has three major sources of water supply: Indus River, hill torrents from the Khirthar Mountain range and the Right Bank Outfall Drain (RBOD-I)/Main Nara Valley Drain (MNVD). The water supply of the lake from the first two sources has been reduced due to morphological and climate changes. Hence, there is only one, and polluted, water supply to the lake, the RBOD-I/MNVD. At the same time, the use of poisonous materials for fishing has further contaminated the lake’s water. The RBOD system is connected with RBOD-III, RBOD-I/MNVD, Indus Link and RBOD-II on the right side of Indus River for safe disposal of wastewater into the Arabian Sea, which is still not functioning. Hence, more than 4500 cusecs of wastewater from the catchment area of RBOD have directly been discharged into the lake causing severe impact on flora, fauna and the livelihood of locals. In order to analyze the lake water quality impact, the water quality index (WQI) model was used. The results indicate that the water quality of four samples was very poor, while the fifth sample was unsuitable for drinking. The results of statistical analysis of parameters such as TDS, EC, SO4, Cl, Na, and hardness are higher to their permissible limits. Consequently, lake water possesses a high potential risk to local consumers and aquatic ecology.
Civil Aircraft Emissions Study and Pollutant Forecasting at a Brazilian Airport
Authors: Pamplona D. A. , Alves C. J. P.
Published: November 2020

In recent decades, the emissions of air transport industry pollutants and their impact on human health attract increased focus. The continued growth of air traffic and public awareness has transformed this field into one of the most important topics of commercial aviation. In the next 20 years, the estimated global demand for air transport will grow by an average of 5%. One of the direct consequences would be the increase in emissions, affecting significantly the communities around airports. The aim of this paper is to present an econometric model forecast of pollutant emissions generated by domestic flights in Salvador Airport. This model includes a derivative study of demand until the year 2020, considering the number of flights and emissions generated in the takeoff and landing cycles. Results present a predictive model for the number of pollutant emissions.
Nonlinear System Identification using Uncoupled State Multi-model Approach: Application to the PCB Soldering System
Authors: Khouni S. , Hemsas K. E.
Published: November 2020

Multi-model approach is an adapted tool of modeling nonlinear systems. The underlying idea is to simplify the complex nature of the system to be studied by decomposing it into simple (linear) sub-systems, in order to simplify the study (stability, control law, surveillance, etc.). This technique allows us to extend the application of linear systems methodology to nonlinear systems. This paper presents nonlinear system identification using an uncoupled state multi-model applied to a Printed Circuit Boards (PCB) soldering system. Precision, simplicity, and fidelity of the obtained results show the effectiveness of the used algorithm to identify, model, and write down as simple sub-systems, a complex black box system.
Horizontal Web Reinforcement Configuration Analysis of Deep Beam Capacity and Behavior using Finite Element Modeling
Authors: Pranata A. Y. , Tjitradi D. , Prasetia I.
Published: November 2020

A deep beam is a beam with a small ratio of its shear span to its effective depth. Deep beams at failure under shear mechanism behave as brittle in contrast to the normal beams which become ductile under the flexural mechanism. The shear failure of deeps beams can be prevented by providing a sufficient amount of web shear reinforcements. Providing horizontal web reinforcement to the RC deep beams is a way to increase their capacity to shear. Testing of the studied deep beams was performed by Finite Element Method (FEM) modeling with the aid of ANSYS software. To obtain valid parameters for modeling RC deep beams in FEM modeling, calibrating test have to be done through verification and validation processes. The study results of all studied RC deep beams show that by closing up the spacing between the horizontal web reinforcement results in increment in the ultimate load, while the ultimate deflection and the curvature ductility were found to be decreasing. For RC deep beams, the placing configuration of horizontal web reinforcement at 0.5h-0.7h was found to be efficient for gaining higher values of ultimate deflection and curvature ductility compared to the placing configuration at 0.3h-0.5h with similar values of ultimate load. It was also found that all the specimens’ crack patterns at the first crack state were caused by flexural-tension while at the ultimate state, they were caused by the shear mechanism.
SOGI-based Flexible Grid Connection of PV Power Three Phase Converters under Non-ideal Grid Conditions
Authors: Abbassi R.
Published: November 2020

This paper proposes a control strategy of improving the power quality of the energy exchanged between a photovoltaic generator (PVG) and an unbalanced grid. A voltage source inverter (VSI) allowing the control of the zero-sequence during unbalanced regimes is proposed. A Second-Order Generalized Integrators-Based Approach (SOGI-BA), which suitably fits with the network's imbalances while ensuring the perfect isolation of the PVG from the adverse effects of the imbalance, is investigated. The investigation will focus mainly on three control objectives: the generation of a balanced current system, the active and reactive power's dependent control, and the elimination of the second frequency DC bus voltage fluctuations. The performance of this new approach is approved by various tests via MATLAB environment simulations.
CMOS Compatible Plasmonic Refractive Index Sensor based on Heavily Doped Silicon Waveguide
Authors: Faruque M. O. , Al Mahmud R. , Sagor R. H.
Published: November 2020

In this study, a plasmonic refractive index (RI) sensor using heavily n-doped silicon waveguide is designed and numerically simulated using finite element method (FEM). The reported sensor is based on gratings inside a heavily doped silicon waveguide structure instead of a conventional metal-insulator-metal structure. This feature enables the device to overcome the limitations of conventional plasmonic devices like optical losses, polarization management, etc. Besides, it makes the device compatible with Complementary Metal Oxide Semiconductor (CMOS) technology and thus provides an easier way of practical fabrication and incorporation in integrated circuits. The presented sensor has a highest sensitivity of 1208.9nm/RIU and a resolution as small as 0.005 which is comparable with conventional plasmonic sensors reported to date. The main advantage of this plasmonic sensor is that it has a very simple structure and uses silicon instead of metal which provides an easier way of fabrication.
INMTD: Intent-based Moving Target Defense Framework using Software Defined Networks
Authors: Hyder M. F. , Ismail M. A.
Published: November 2020

Intent-Based Networking (IBN) is an emerging networking paradigm while Moving Target Defense (MTD) is an active security technique. In this paper, the Intent-based Moving Target Defense (INMTD) framework using Software Defined Networks is proposed. INMTD is the first effort in exploiting IBN for the design of an efficient Moving Target Defense (MTD) framework. INMTD uses the concept of shadow servers in order to counter the first stage of cyber-attacks, i.e. reconnaissance attacks targeted against servers running in SDN networks. INMTD comprises of an MTD application running on an SDN controller. The MTD application has reconnaissance detection, MTD movement, and MTD monitoring modules. The MTD application is integrated with the intent-based northbound API of SDN controller. INMTD not only provides protection against probing attacks, but it also provides high availability due to shadow servers. The proposed framework was implemented using Mininet and ONOS SDN controller. The proposed framework was assessed in terms of defender cost, attacker’s effort, and introduced complexity in the system. The results substantiate the efficient protection against reconnaissance attacks at lower computational cost.
Impact of the Effluents of Hyderabad City, Tando Muhammad Khan, and Matli on Phuleli Canal Water
Authors: Mahessar A. A. , Qureshi S. , Qureshi A. L. , Ansari K. , Dars G. H.
Published: November 2020

The demand and supply of safe water is a basic need. The consumption of clean water intensified with population growth and economic development which in turn cause degradation of available freshwater resources while creating huge volumes of wastewater, solid waste, and serious environmental problems. This paper presents the impact of disposing of domestic/industrial effluents into an irrigation canal. The subsequent contamination of the canal water becomes a public health risk. The non-perennial Phuleli canal with a discharge of 15,026 cusecs, takes in water from the left bank of Kotri Barrage, which is the last controlling hydraulic structure on the Indus River. This canal runs from the periphery of Hyderabad, Tando Muhammad Khan (TM Khan) and Matli cities and supplies water for domestic, agricultural, and industrial activities. The canal water is the only source of drinking water for millions of people because the groundwater in the command area of the canal is highly saline. The banks on both sides of the canal have encroached in cities’ areas. The huge volume of solid waste and municipal and industrial wastewater from these cities and from the occupied canal banks are dumped directly into the canal without any treatment. The collected samples’ were analyzed for pH, EC, TDS, Cl, SO4, HCO3, hardness, Na, K, Ca, and Mg. These results show higher than permissible limits as per NEQS and WHO. The Karl Pearson matrix correlation of parameters reveals strong relation among EC with TDS and CL with SO4, Mg with K and moderated relationship among the other parameters except for pH and DO. Water Quality Index (WQI) model indicates that the water quality of the canal is poor and unfit for drinking. Hence the consumption of canal water is a high potential health risk for locals.
A Study of Joint Cost Inclusion in Linear Programming Optimization
Authors: Armaos P.
Published: November 2020

The concept of Structural Optimization has been a topic or research over the past century. Linear Programming Optimization has proved being the most reliable method of structural optimization. Global advances in linear programming optimization have been recently powered by University of Sheffield researchers, to include joint cost, self-weight and buckling considerations. A joint cost inclusion scopes to reduce the number of joints existing in an optimized structural solution, transforming it to a practically viable solution. The topic of the current paper is to investigate the effects of joint cost inclusion, as this is currently implemented in the optimization code. An extended literature review on this subject was conducted prior to familiarization with small scale optimization software. Using IntelliFORM software, a structured series of problems were set and analyzed. The joint cost tests examined benchmark problems and their consequent changes in the member topology, as the design domain was expanding. The findings of the analyses were remarkable and are being commented further on. The distinct topologies of solutions created by optimization processes are also recognized. Finally an alternative strategy of penalizing joints is presented.
Prediction of Daily Global Solar Radiation using Resilient-propagation Artificial Neural Network and Historical Data: A Case Study of Hail, Saudi Arabia
Authors: Boubaker S. , Kamel S. , Kchaou M.
Published: November 2020

In this paper, several different Feed Forward Artificial Neural Networks (FFANNs) were used for forecasting the one-day-ahead Global Horizontal Irradiation (GHI) in Hail region, Saudi Arabia. The main motivation behind predicting GHI is that it is a critical parameter in sizing and planning photovoltaic water pumping systems. The novelty of the proposed approach is that it employs only the historical values of the GHI itself as explanatory variables and a fast training algorithm (resilient-propagation). In terms of performance metrics, the rp-trained FFANNs provided better results than Quasi-Newton (bfg) algorithm trained FFANNs for almost all the studied combinations of the FFANN structure. It has been also shown that increasing the number of neurons per layer didn’t improve the performance. Medium structures with fast training algorithms are recommended.
Risk Management in Engineering and Construction: A Case Study in Design-Build Projects in Vietnam
Authors: Nguyen P. T. , Nguyen P. C.
Published: November 2020

The constant demand for construction in developing countries like Vietnam causes more and more challenges and difficulties to Project Management Units (PMUs) in carrying projects to completion on schedule, with quality assurance and fewer costs. In order to do this, PMUs need to have better and tighter management tools and forms. However, in order to minimize risks during project implementation, the binding terms in contracts are also becoming stricter with more and more new forms of contracts. One of them is the design-build (DB) contract form. This paper presents the critical risk factors for design-build projects in the construction industry. Good identification and management of these risk factors will help projects succeed and will increase the confidence of owners and contractors who seek to use the design-build form.
Microstructural Analysis of Silica Fume Concrete with Scanning Electron Microscopy and X-Ray Diffraction
Authors: Uzbas B. , Aydin A. C.
Published: November 2020

The effects of using different ratios of silica fume on the mechanical and microstructural properties of hardened cement paste and concrete were investigated in this study. Portland cement was replaced with 5%, 10%, 15%, and 20% silica fume (SF) by weight. Microstructural properties of obtained samples were investigated by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD analysis showed that the ratio of calcium hydroxide (CH), which is produced by hydration, decreases depending on the concrete age and the amount of silica fume. The SEM analysis showed that the use of silica fume decreases gaps and calcium silicate hydrate (C-S-H) which is also a hydration production. Silica fume content of up to 15% improved the observed mechanical and microstructural properties of concrete. At the optimum value of 15%, improvement in the paste was observed due to the filler effect and the reaction between the silica fume and calcium hydroxide, leading to a reduction in calcium hydroxide in the concrete.
Impact Assessment of Groundwater Quality using WQI and Geospatial tools: A Case Study of Islamkot, Tharparkar, Pakistan
Authors: Kumar N. , Mahessar A. A. , Memon S. A. , Ansari K. , Qureshi A. L.
Published: November 2020

Groundwater is the only source of fresh water in the Thar Desert which is located in an arid region of Pakistan with dense population and spreads over 19,638km2. Low rainfall, low groundwater recharge, high evaporation and absence of perennial streams are the general reasons for water scarcity. Being the single water source for drinking, domestic and industrial uses, and livestock activities, this source is highly overexploited. Realizing the gravity of the situation, this paper presents a groundwater quality evaluation of Islamkot, Tharparkar, using Water Quality Index (WQI) and Geospatial tools. 40 samples were collected from dug wells. The TDS of 28 samples was found higher than 3000mg/L and 12 samples ranged from 1500 to 3000mg/L. Many (28) samples were not further analyzed due to their very high TDS which made the water unfit for drinking. Twelve samples with TDS ranging from 1500 to 3000 mg/L were further analyzed. The analyzed results revealed the average values of pH, EC, TDS, salinity, chloride, total alkalinity, fluoride, and arsenic. The results did not meet NEQS and WHO guidelines. Pearson correlation analysis was conducted among parameters. Further, groundwater quality was assessed by WQI and indicated that water quality varied from very poor to unsuitable for drinking. The consumption of polluted groundwater has been the main cause of prevalent waterborne diseases and poses a very high risk for public health
Parametric Study of Pile Response to Side-by-Side Twin Tunneling in Stiff Clay
Authors: Mangi N. , Bangwar D. K. , Karira H. , Kalhoro S. , Siddiqui G. R.
Published: November 2020

A three dimensional coupled-consolidation numerical parametric study was carried out in order to gain new insight of single pile response to side-by-side twin tunneling in saturated stiff clay. An advanced hypo plasticity (clay) constitutive model with small-strain stiffness was adopted. The effects of relative to the pile tunnel depths were investigated by simulating the twin tunnels near the pile at various depths of tunnels, namely near the pile shaft, adjacent to the pile toe, and below the pile toe. It was found that the second tunneling in each case resulted in a larger settlement than the one due to the first tunneling with a maximum percentage difference of 175% in the case of twin tunneling near the mid-depth of the shaft. This occurred due to the degradation of clay stiffness around the pile during the first tunneling. Conversely, the first tunneling-induced bending moment was reduced substantially during the second tunneling. The most critical location of twin tunnels relative to the pile was found to be below the pile toe.
A System Dynamics Modeling and Computer-based Simulation in Forecasting Long-term Sufficiency: A Philippine Chicken Meat Sector Case Study
Authors: Espino M. T. M. , Bellotindos L. M.
Published: November 2020

As the human population continues to grow, the global growth of the livestock sector will continue to rise as well. In the Philippines, the demand for chicken meat is projected to triple by 2050. In this study, the increasing consumption and long-term sufficiency were evaluated with the use of the system dynamics concept. With system modeling and computer-based simulation techniques, the available data on chicken meat supply chain were processed considering that factors behave dynamically. The simulated model facilitated the forecasting of key variables which may drop sufficiency from 87% in 2015 to 60% by 2050 if no proper actions take place in the areas of production and consumption. As a whole, this study developed and demonstrated preliminary system dynamics-based and computer based-approaches in order to understand the chicken meat sector. This showed that a dynamic systems-based paradigm shift in food and agricultural systems analysis can help address operational and strategic issues regarding food security.
Electrical Device Protection from Overvoltage in a DC Power Supply Network: Fast-acting Protection, Realized by an “Artificial” Short Circuit in the Input of the Protected Device
Authors: Filipova-Petrakieva S. K. , Shopov Y. M.
Published: November 2020

In the present paper a protective device based on the so-called “artificial” short circuit in the input of the network, is proposed. To ensure the necessary time for switching on the protection, the increased power supply voltage is delayed to reach in the input of the protected device by additional inductance L, which is connected in series to the power supply. As a result of this forced short circuit, the DC-power supply is switched off by a standard protective circuit-breaker. The short circuit is realized by a fast-acting semi-conductor device (e.g. diac + thyristor, etc.). The controlling signal is formed as a voltage across a capacitor that is a part of RC-circuits connected in parallel to the DC-power supply network. An analytical expression for this voltage, using a classical method for transient analysis, is obtained. The main aim is to determine the exact time of switching on the protection. The research is confirmed with simulations by OrCAD PSpice under the exact values of the elements in the RC-circuits considered. Two rapid increase cases in the power supply voltage are considered: positive jump and linear increase. The suggested solution is applicable for overvoltage protection of different electrical devices. The electrical scheme, based on the electronic components, ensures a fast-acting breaking, which guarantees secure protection. Based on the analytical expressions, the synthesis of the circuit for control and protection is made and the respective values of its elements are calculated.
Simple Implementation of a Fuzzy Logic Speed Controller for a PMDC Motor with a Low Cost Arduino Mega
Authors: Belkhir K. S.
Published: November 2020

Control of the permanent magnetic direct current PMDC motor is a common practice, hence the importance of the implementation of the PMDC motor speed controller. The results of a fuzzy logic speed controller for the PMDC motor rely on an appropriate base. As the dimension of the rules increases, its difficulty rises which affects computation time and memory requirements. Fuzzy Logic Controller (FLC) can be carried out by a low-cost Arduino Mega which has a small flash memory and a maximum clock speed of 16MHz. It is realized by three membership functions and each was divided into three memberships. The results of the FLC are satisfactory, revealing superior transient and steady-state performance. In addition, the controller is robust to speed mode variations.
Simulation Models For Three-Phase Grid Connected PV Inverters Enabling Current Limitation Under Unbalanced Faults
Authors: Lam L. H. , Phuc T. D. H. , Hieu N. H.
Published: November 2020

Normally unbalanced grid voltage dips may lead to unbalanced non-sinusoidal current injections, DC-link voltage oscillations, and active and/or reactive power oscillations with twice the grid fundamental frequency in three-phase grid-connected Photovoltaic (PV) systems. Double grid frequency oscillations at the DC-link of the conventional two-stage PV inverters can further deteriorate the DC-link capacitor, which is one of the most important limiting components in the system. Proper control of these converters may efficiently address this problem. In such solutions, Current Reference Calculation (CRC) is one of the most important issues that should be coped with the reliable operation of grid-connected converters under unbalanced grid faults. Therefore, this paper proposes and simulates CRC methods and presents the results in order to improve the quality of the grid-connected PV system under unbalanced grid voltage fault.
Dynamic Modeling and Simulation of a PEM Fuel Cell (PEMFC) during an Automotive Vehicle’s Driving Cycle
Authors: Biberci M. A. , Celik M. B.
Published: November 2020

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) are the most appropriate type of fuel cells for application in vehicles due to their low operational temperature and high-power density. In this paper, a zero-dimensional, steady state thermodynamic modeling for an automotive 90kW PEMFC system has been built up in order to investigate the effects of operating parameters such as vehicle acceleration and operating pressure on the size of the system elements, heat and water system constitution, fuel consumption, and efficiency. A dynamic model was formed for the fuel cell power system in MATLAB. Power output and power losses of the system were investigated at 3atm operation pressures.
Reinforcement and Restoration Studies of the Edremit Ataturk House
Authors: Bagbanci B. M.
Published: November 2020

Edremit Ataturk House has been restored under international restoration principles. Due to its importance, a systematic study was carried out to prevent the building from suffering damage. The current situation of the building was investigated by using slightly destructive and non-destructive test methods. Flat-jack and shear tests were used in order to identify the mechanical properties of masonry walls according to the ASTM standards. The operational modal analysis test method was used in order to understand its dynamic characteristics. After the diagnosis phase, a finite element model was prepared and calibrated according to the in-situ test results. The reinforcement studies were performed according to the finite element modal analysis results. Finally, the differences between the dynamic properties of the structure were evaluated by vibration tests before and after the restoration works.
A Low-cost Artificial Neural Network Model for Raspberry Pi
Authors: Truong S. N.
Published: November 2020

In this paper, a ternary neural network with complementary binary arrays is proposed for representing the signed synaptic weights. The proposed ternary neural network is deployed on a low-cost Raspberry Pi board embedded system for the application of speech and image recognition. In conventional neural networks, the signed synaptic weights of –1, 0, and 1 are represented by 8-bit integers. To reduce the amount of required memory for signed synaptic weights, the signed values were represented by a complementary binary array. For the binary inputs, the multiplication of two binary numbers is replaced by the bit-wise AND operation to speed up the performance of the neural network. Regarding image recognition, the MINST dataset was used for training and testing of the proposed neural network. The recognition rate was as high as 94%. The proposed ternary neural network was applied to real-time object recognition. The recognition rate for recognizing 10 simple objects captured from the camera was 89%. The proposed ternary neural network with the complementary binary array for representing the signed synaptic weights can reduce the required memory for storing the model’s parameters and internal parameters by 75%. The proposed ternary neural network is 4.2, 2.7, and 2.4 times faster than the conventional ternary neural network for MNIST image recognition, speech commands recognition, and real-time object recognition respectively.
Rice Husk Ash and Fly Ash Effects on the Mechanical Properties of Concrete
Authors: Bheel N. , Jokhio M. A. , Abbasi J. A. , Lashari H. B. , Qureshi M. I. , Qureshi A. S.
Published: November 2020

Cement production involves high amounts of energy consumption and carbon dioxide emissions. Pakistan is facing a serious energy crisis and cement’s cost is increasing. In addition, landfilling of potential concrete components can lead to environmental degradation. The use of waste as cement replacement not only reduces cement production cost by reducing energy consumption, but it is also environmentally friendly. The purpose of this study is to analyze the characteristics of concrete by partially replacing cement with Rice Husk Ash (RHA) and Fly Ash (FA). This study is mainly focused on the performance of concrete conducting a slump test, and investigating indirect tensile and compressive strength. Cement was replaced with RHA and FA by 5% (2.5% RHA + 2.5% FA), 10% (5% RHA + 5% FA), 15% (7.5% RHA + 7.5% FA) and 20% (10% RHA+10% FA) by weight. Ninety concrete samples were cast with mix proportions of 1:2:4 and 0.55 water/cement ratio. Cube and cylindrical samples were used for measuring compressive and split tensile strength respectively, after 7 and 28 days. The results showed that after 28 days, the 5% RHA+5% FA sample’s compressive strength was enhanced by 16.14% and its indirect tensile strength was improved by 15.20% compared to the conventional sample. Moreover, the sample’s slump value dropped as the content of RHA and FA increased.
Investigation of the Visible Light-Sensitive ZnO Photocatalytic Thin Films
Authors: Nadareishvili M. M. , Mamniashvili G. , Jishiashvili D. , Abramishvili G. , Ramana C. , Ramsden J.
Published: November 2020

ZnO photocatalytic thin films deposited on a glass substrate are obtained by chemical spraying technique, and they are active in the visible light spectrum. Optical studies have shown that ZnO thin films doped by nickel impurities absorb visible light at wavelengths from 400nm to 600nm. At the same time, this absorption rate increases with the increase of concentration of nickel impurities. At high concentration (5%), the absorption of light is reduced in the visible area, but after heat treatment at 6000C the light absorption in these samples improves, which allows us to conclude that the observed effect is caused by a violation of the homogeneity of the distribution of nickel impurities and the creation of agglomerates. Decoration of ZnO thin film surfaces by silver clusters improves light absorption, as it happens to the nanopowders, but in the case of thin films, this effect is much smaller. Experiments on methylene blue determine the significance of photocatalytic activity in the visible area of sun irradiation of ZnO thin films containing nickel impurities, which are obtained by chemical spraying technique.
Insulating Materials at Very Low Temperatures: A Short Review
Authors: Malelis P. , Danikas M.
Published: November 2020

In this paper, a short review is given on insulating materials at very low temperatures. Various insulating materials are investigated in terms of phenomena such as partial discharges. Some of the factors affecting the behavior of the insulating materials at very low temperatures, such as the quality of electrode surface, the stressed insulation volume and the existing bubbles, are also reported and commented upon. Proposals for future research are also discussed.
Reconfigurable Hardware Design for Automatic Epilepsy Seizure Detection using EEG Signals
Authors: Rafiammal S. S. , Jamal D. N. , Mohideen S. K.
Published: November 2020

Reconfigurable circuit designs for automatic seizure detection devices are essential to prevent epilepsy affected people from severe injuries and other health-related problems. In this proposed design, an automatic seizure detection algorithm based on the Linear binary Support Vector Machine learning algorithm (LSVM) is developed and implemented in a Field-Programmable Gate Array (FPGA). The experimental results showed that the mean detection accuracy is 86% and sensitivity is 97%. The resource utilization of the implemented design is less when compared to existing hardware implementations. The power consumption of the proposed design is 76mW at 100MHz. The experimental results assure that a physician can make use of this proposed design in detecting seizure events.
Classification of Volcanic Rocks based on Rough Set Theory
Authors: Shaaban S. M. , Tawfik S. Z.
Published: November 2020

Classification of volcanic rocks is a fundamental task in the geologic studies. Volcanic rocks are igneous rocks that cooled rapidly above the surface of the Earth's crust. They are classified according to their oxide chemical content. Furthermore, volcanic rocks can also be classified numerically by statistical means. But these methods are mostly dependent on human expert decision making and have a high cost. In this paper, a novel approach in the classification of volcanic rocks is proposed. This method is based on the rough set mathematical theory. The continuous data of the information system are firstly discretized using the information loss method. Secondly, the discretized decision table is reduced and the decision rule sets are extracted. The results are consistent with previous methods and show that the proposed method reduces time and calculation costs.
Model Reference Adaptive Controller for LTI Systems with Time-variant Delay
Authors: Keltoum G.
Published: November 2020

In this paper, a new Direct Model Reference Adaptive Control Procedure (DMRAC) for Linear Time-Invariant (LTI) delay systems is presented with the use of the concept of the command generator tracker which expands the class of processes that can now be controlled with zero output error. The stability of the error between the system and the model is guaranteed by the Lyapunov theory. The new algorithm is applied to control a perturbed delay system. Matlab simulation examples are given to demonstrate the usefulness of the algorithm.
Transient Stability Augmentation of the Algerian South-Eastern Power System including PV Systems and STATCOM
Authors: Bouhadouza B. , Bouktir T. , Bourenane A.
Published: November 2020

The transient stability of the 12-bus Algerian southeast power system is studied in this paper. This electrical system has abundant reactive power due to the long transmission lines and generators’ voltage. This capacitive power increases bus voltage which leads to network instability. The use of conventional compensators does not provide adequate and fast solutions. FACTS technology improves the efficiency of these compensators in solving the problem of power system instability efficiently. Among its elements, a synchronous compensator STATCOM control is proposed to decrease bus overvoltage and damping oscillations. Disturbance at bus B-1 is taken into consideration. This disturbance represents the photovoltaic (PV) array which exploits the abundantly available solar irradiation in the desert of Algeria. Various simulation tests have been carried out using NEPLAN software and the proposed design algorithms are proved in the relevant discussion.