Showing papers in "The Journal of Engineering Research in 2018"

Investigation of nickel removal using poly(amidoamine) generation 4 dendrimer (PAMAM G4) from aqueous solutions

Abstract: Dendrimers are branched molecules that have medical, pharmaceutical, and environmental applications. Dendrimers of polyamidoamine (PAMAM) with functional groups of hydroxyl and amine are useful for making complex of heavy metals. The aim of this experimental study is to utilize dendrimer PAMAM G4 in removing nickel. FTIR and DLS analyses were conducted for determining the structure of the dendrimer. The efficiency of the process was examined under different conditions including different pHs (3, 7, 11), the concentration of the dendrimer adsorbent (0.5-2.5 g/L), the nickel concentration (5-25 mg/L), and different reaction times (5-60 min). The data analysis were carried out using with SPSS. With the increase in the reaction time at constant values of the dendrimer (1g/L), the nickel removal (C= 20 mg/L), at the pHs of 3, 7, and 11 increased from 7 to 18.5, from 45 to 69, and from 54 to 73, respectively. With the increase in the concentration of nickel from 5 to 25 mg/L, the removal efficiency at pH=11 decreased from 97 to 59%. The optimal value of the dendrimer for removing nickel was obtained as 1.5 g/L. The adsorption reaction followed Freundlich isotherm (R 2 =0.95). Through optimizing different conditions it is possible to use this adsorbent as a method with suitable effectiveness in removing heavy metals including nickel from industrial wastewaters.

SNT Algorithm and DCS Protocols coalesced a Contemporary Hasty File Sharing with Network Coding Influence

Abstract: Network coding has presently drawn marvelous attention and gifted enrichment of routing to improve network throughput. In this paper, we propose a swift network transfer (SNT) algorithm and deduplication, caching, and security (DCS) protocols to enhance the performance of peer-topeer fast file sharing with network coding that can attain 10% to 15% privileged throughput when compared to that of other P2P multicast networks. Initially, it is proposed to find peer nearness on the network using swift network transfer (SNT) algorithm. Secondly, the functions of protocols used in the proposed concept are analyzed, where, in the first protocol, there is deduplication to abolish replica photocopy of files for maintaining the database storage space effectively. The second protocol network caching enables us to find file request node in data flow. The last protocol is command and control performances to provide security for checking IP address and mismatch of uplink and downlink transmission nodes.

Renewable energy for rural development in Turkey

Abstract: In last three decades, Turkey’s rural energy development has achieved some success. The average cooking efficiencies increased from 25% in 1980 to 60% in 2010, more than 99% of townships and villages have electric connection, remarkable progress in biomass, hydropower and other renewable energy also has been made. Since the late 1980s, both the rural economy and rural energy consumption have changed dramatically. In order to reduce dependency on imported expensive fossil fuels, Turkey should be used the renewable energy sources, because they are domestic and abundant. However considering the total cost of renewable energy production, these sources can be used not to replace the fossil fuels, but to supply energy requirement in the country. Renewable energy is being pointed as a potentially significant new source of jobs and climate change mitigation. This paper discusses the status, features, and trends, as well as technical potentials of renewable energy for rural development in Turkey. The present study also shows that there is enough renewable potential for meeting the country energy and electricity demand.

Sound quality evaluation for vehicle door opening sound using psychoacoustic parameters

Abstract: The sound of a door opening on a vehicle has a main influence on psychological comfort and affective satisfaction for the vehicle. This study aims to evaluate the auditory pleasantness of the door opening sound and to derive the sound parameters, which can optimize that pleasantness. Fourteen different door opening sounds were selected and recorded. Participants evaluated each recorded door opening sound with the designed questionnaire. Three main results were obtained. First, the questionnaire was developed to evaluate the auditory pleasantness of door opening sound based on five affective attributes: ‘loud’, ‘sharp’, ‘rough’, ‘clear’, and ‘satisfy’. These were selected through previous literature review and expert interviews. Second, ‘Loudness’, ‘sharpness’, ‘roughness’, ‘fluctuation strength’, and ‘tonality’ were selected as the psychoacoustic parameters. These parameters were found to be the important dimensions for the perception of door opening sound. Each affective attribute was related to psychoacoustic parameters by correlation analysis. Finally, the authors developed a model to predict subjective response to the door opening sound through regression analysis. In the incidence of ‘loud’, ‘sharp’, and ‘rough’, high R2 values were shown. Multiple regression was used to create a model to predict auditory pleasantness. The psychoacoustic parameter ‘loudness’ was shown to have a major effect on auditory pleasantness. The parameters ‘loudness’, ‘sharpness’, and ‘roughness’ were shown to affect the attributes of the door opening sound. The result of this study was an optimal model, created through psychoacoustic parameters, to predict the auditory pleasantness of door opening sounds.

Renewable energy potential, utilization and policies in Turkey for environmental friendly sustainable development

Abstract: Renewable energy technologies such as wind, biomass, hydropower, geothermal and solar are finally showing maturity. Turkey’s carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for sustainable energy development in Turkey. Turkey’s geographical location has several advantages for extensive use of most of these renewable energy sources. This study shows that there is enough renewable energy potential in Turkey for heat and electricity generation. Especially hydropower, biomass, solar and wind are very well.

Robust trajectory tracking control of robotic manipulators based on model-free PID-SMC approach

Abstract: In this paper, a robust controller based on proportional-derivative control and sliding mode control for trajectory tracking problem of a nonlinear robotic manipulator is presented. Actuator dynamics is taken into account in tracking control simulations for verification of good precision trajectory tracking. A low pass filter is employed for the elimination of chattering, high frequency components, and noises. The proposed control scheme combines the simplicity feature of the proportional-integral-derivative (PID) controller and the robustness feature of the sliding mode control (SMC). There is no need to know the dynamic model of controlled systems, unlike most robust controllers, and only the upper bound of the dynamic system is required in the proposed method. Lyapunov’s stability method is used to prove robustness of the proposed controller for the robot manipulator subjected to system uncertainties and external disturbance. The performance of the proposed controller is simulated by MATLAB-Simulink environment and is compared with other control schemes to verify its efficiency with various control methods commonly preferred in robotic manipulators. Robustness tests of the proposed controller against uncertainties in robot and actuator dynamics and external disturbance are illustrated.

Design and analysis of high speed optical routers for next generation data centre network

Abstract: Advanced optical switching systems are required for connecting next generation high performance data center system. It provides scaling of thousands of ports and at the same time it achieves low communication latency and reduced power consumption. For providing fast optical switching the arrayed waveguide grating (AWG) routers are used in the core of many switches. The AWG is preferred because of its inherent ability to perform wavelength routing of many wavelengths parallelly. The AWG is an energy efficient device and due to high bandwidth switching capabilities, simple design and low cost features this is most preferable device in optical switching technology. The physical and network layer analysis of two AWG based switch architecture are presented in the paper and a comparison is performed between switches through this analysis. The simulation results discussed in this paper show that the design of our proposed switch is far better than a recently published design. The cost analysis of each switch is also considered in the paper that shows our proposed switch design is relatively more cost efficient.

Landscape Architecture and The Saudi Arabia Quality of Life Program

Abstract: Saudi Arabia has for decades felt the effects of the declining condition of its urban, social and natural environments. The government has set out a long-term vision to address these issues through 12 major programs, one of which is the Quality of Life Program 2020. The Program mainly focuses on making Saudi Arabia a top living destination by improving individuals’ lifestyles and enhancing their quality of life. This paper considers the importance of landscape architecture to the Program by way of a literature review to clarify the role of the landscape architecture profession and an analysis of the projects that underlie the Program to highlight the profession’s potential to contribute to these projects.

Evaluation of 3D printers used in additive manufacturing by using interval type-2 fuzzy TOPSIS method

Abstract: Recently, additive manufacturing technology, which is used in production and especially in prototyping, provides facilities to manufacturers in terms of speed and cost. 3D (three-dimensional) printer technologies used in additive manufacturing make itself felt in almost every sector. There are many functional 3D printers in the market and many criteria are considered in the purchase process. Because the selection of an incorrect printer can cause problems to manufacturers in terms of production and time. For this, multi-criteria decision-making methods can be used to select the suitable 3D printer. In this study, it is aimed to select the most suitable 3D printer that will buy for use in prototyping operations of a company operating in production sector. According to the defined criteria (max printing volume, layer resolution, price, positioning precision), the interval type-2 fuzzy TOPSIS method is used to evaluate the alternatives. At the end of the study, sensitivity analysis is performed, alternatives are evaluated, and finally the most suitable 3D printer is determined.

mechanical engineering in ancient Egypt, Part 63: Palettes industry

Abstract: The objective of this paper is to investigate the development of mechanical engineering in ancient Egypt through the production of palettes during the Predynastic to Late Periods. This study covers the different applications of palettes in the ancient Egyptian society during a time span of about 4000 years. The material, dimensions, use and location of each palette are highlighted. The features and mechanical engineering tradition in each palette are investigated.

Race classification using gaussian-based weight K-nn algorithm for face recognition

Abstract: One of the greatest challenges in facial recognition systems is to recognize faces around different race and illuminations. Chromaticity is an essential factor in facial recognition and shows the intensity of the color in a pixel, it can greatly vary depending on the lighting conditions. The race classification scheme proposed which is Gaussian based-weighted K-Nearest Neighbor classifier in this paper, has very sensitive to illumination intensity. The main idea is first to identify the minority class instances in the training data and then generalize them to Gaussian function as concept for the minority class. By using combination of K-NN algorithm with Gaussian formula for race classification. In this paper, image processing is divided into two phases. The first is preprocessing phase. There are three preprocessing comprises of auto contrast balance, noise reduction and auto-color balancing. The second phase is face processing which contains six steps; face detection, illumination normalization, feature extraction, skin segmentation, race classification and face recognition. There are two type of dataset are being used; first FERET dataset where images inside this dataset involve of illumination variations. The second is Caltech dataset which images side this dataset contains noises.

Performance Optimization of Centrifugal Pump for Crude Oil Delivery

Abstract: Crude oil transport is an essential task in oil and gas industries, where centrifugal pumps are extensively used. The design of a centrifugal pump involves a number of independent parameters which affect the pump performance. Altering some of the parameters within a realistic range improves pump performance and saves a significant amount of energy. The present research investigated the pump characteristics by modifying the number of blades and the exit blade-angles. Reynolds-Averaged Navier-Stokes equations with standard k - e two-equation turbulence closure were used for steady and incompressible flow of crude oil through the pump. The experimental set-up was installed and the pump performance calculated numerically was compared with the experiments. The investigations showed that the number of blades and the exit blade-angles have a significant influence on the head, shaft power, and efficiency. The vortical flow structures, recirculation and reverse flow characteristics around the impeller were investigated to explain the flow dynamics of impeller and casing. A larger number of blades on the rotor showed dominant streamlined flow without any wake phenomena. The combined effect of the number of blades and exit blade angle has led to an increase in head and efficiency through the parametric optimization.

Investigation of energy saving potentials of a food factory by energy audit

Abstract: There is no doubt that energy efficiency is the best solution for the challenges of modern society such as global warming, environmental impact assessment, industrial ecology, improved energy management and new energy sources Within this scope, energy efficiency policy has been developed by the many countries to minimize the energy consumption of unit products and to recover the industrial waste heat This paper presents a case study for determining whole energy saving potentials arising from the main selected equipments in a biscuit factory For this purpose, several instruments were used to measure heat losses, surface temperatures, properties of stack gas, flow rate of stack gas and luminous intensity, etc From the analysis results, it reveals that total energy saving amount based on natural gas and electricity is 5096 TOE/year after various remedies, which corresponds to 8% total energy consumption of the investigated equipment in the factory Thus, energy efficiency applications result in a profit of about 24766 $/year and a reduction of 8991 tons CO2 emission per year This study has shown that with the simple applications in food factories, efficient use of energy can be increased and therefore energy intensity can be improved We hope that this study will be a reference for energy managers in food factories to provide more energy savings

Rotary ultrasonic machining of alumina ceramic: Experimental study and optimization of machining responses

Abstract: In the present competitive structure of manufacturing and industrial applications, alumina ceramic has been well observed as one of the highly demanded advanced ceramics owing to its excellent and superior properties. The objective of this article is to experimentally investigate the influence of several process variables namely; spindle speed, feed rate, coolant pressure, and ultrasonic power on different machining performances i.e. surface roughness, and chipping thickness. Response surface methodology has been employed to design the experiments. Microstructure of the machined samples has been evaluated and analyzed through scanning electron microscope. The existence of plastic deformation has also been observed along with the dominated brittle fracture in rotary ultrasonic machining of alumina ceramic. Feed rate and spindle speed have been observed as most influential parameters that govern the deformation mode in alumina ceramic. The optimization of machining responses has also been conducted by employing desirability theory, and at optimized parametric setting, the obtained experimental values for surface roughness and chipping thickness are, 0.134 µm and 0.073 mm, respectively.

Allocation of distributed generation and battery switching stations for electric vehicle using whale optimiser algorithm

Abstract: With the increasing demand for electrical vehicles (EVs) in the existing distribution system due to road traffic sustainability, fuel costs reduction, and environmental improvement by the promotion of low carbons in transportation, system planners need to minimise energy losses and improve voltage profile of the grid. Few studies resolved these issues via optimum placement of distributed generation (DG) and battery switching station (BSS) units in distribution system; however, these techniques considered only active power loss minimisation with various methodological limitations. Therefore, a new application of whale optimiser algorithm (WOA) is proposed to solve these limitations. The simultaneous placement based approach of the units has been adopted to minimise active and reactive energy losses of 33- and 69-bus distribution systems. System performance has been analyzed based on multiple technical criteria, such as system loading factor, voltage profile improvement, and active and reactive power loss reduction indices. The results of WOA have been proven to be superior to those of artificial bee colony and gravitational search algorithms. Therefore, the proposed methodology can guide energy planners in determining optimal allocation of multiple DG and BSS units in their systems,; in addition to the expected energy loss reduction within the system, BSS, and DG planning and operational constraints.

Phase I monitoring of within-profile autocorrelated multivariate linear profiles

Abstract: As one of the most important subareas of statistical process monitoring (SPM), multivariate profile monitoring has attracted attention in recent years. Most researches on multivariate profile analysis have been carried out under the independency assumption of response values. However, the independency assumption is violated in many real applications, such as when the observations are gathered in short time intervals. In this paper, we focus on Phase I monitoring of multivariate profiles when the consecutive response values within each profile are autocorrelated and follow the autoregressive-moving average (ARMA(1,1)) model. First, a transformation method is applied to eliminate the effect of autocorrelation. Then, two approaches, T2 and Wilks’ lambda, are used to check the stability of the process under different magnitudes of shifts and different parameters of the ARMA(1,1) model. A numerical example based on simulation studies is applied to evaluate the performance of the applied control charts in the presence of within-profile autocorrelation in terms of signal probability criterion. The results show that Wilks’ lambda outperforms the T2 chart in almost all out-of-control situations.

Review of cogeneration and trigeneration systems

Abstract: There is an increasing concern about the need for energy security and impact of greenhouse gas emission all over the world. Energy efficiency has been identified as part of the solution to ensure the energy supply as well as lower the greenhouse gas emissions. CHP (Combined Heating and Power generation) and CCHP (Combined Cooling, Heating and Power generation) systems can contribute to the reduction of primary energy consumption and greenhouse gas emissions in residential and tertiary sectors, by reducing fossil fuels demand and grid losses with respect to conventional systems. The trigeneration systems are characterized by very high energy efficiency (80 to 90%) as well as a less polluting aspect compared to the conventional energy production since the waste heat is recovered from the engine cooling system and exhaust gases to use it for process heating, excess heat is also used to drive an absorption cooling system. In this paper, we will show a review on the studies of the trigeneration power plants in terms of components, modeling, optimization and decision-making techniques. For each section of the paper, a survey of previous studies with CHP/CCHP implementation is presented, along with a survey of the methods used in their modeling, optimization, and decision-making. New topics are discussed concerning the cogeneration and trigeneration systems specially in the modeling, optimization and decision-making techniques. In almost all reviewed works, CCHP systems are found to have positive technical and performance impacts.

A novel method of parameter identification based on nonlinear empirical model for vortex- induced vibration

Abstract: The paper deals with the identification of the parameters of Scanlan’s nonlinear model for the vortex-induced vibrations (VIV) of bridge decks. Although genetic algorithm (GA) has a good search ability, it has difficulties in optimizing the multi-parameter problem to obtain acceptable results. Levenberg-Marquardt algorithm (LMA), a widely used optimization algorithm, is strongly influenced by the initial condition. A novel identification method (GALMA) based on GA and LMA has been proposed. GA is adopted to achieve an initial condition, which is successively used by LMA to optimize the identification. In order to verify the validity of the identified parameters, the reconstructed data is compared with the measured data with respect to the time history of vortex-induced vertical force (VIVF), the frequency components of VIVF, and the time history of displacement response. The result shows that GALMA is effective. Furthermore, compared with other identified methods, GALMA is more precise in identification parameters, especially many parameters of equation.

Optimal allocation of distributed solar photovoltaic generation on electrical distribution system under uncertainties

Abstract: This paper proposes a new method to select the optimal setting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/ generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as an optimization problem with a network loss based objective function under various equality and inequality constraints in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation. This approach reduces the requirement of statistical load/ generation data for uncertainty consideration. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulting optimization problem is solved by a new dynamic harmony search algorithm (DHSA). Dynamic bandwidth (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. The proposed approach is demonstrated with two standard IEEE radial distribution systems under different scenarios.

Shear lag and effective flange width of T-shaped short leg shear walls

Abstract: Short leg shear wall structure is a new-type residential structure, which is widely used in China, and T-shaped short leg shear wall is a commonly used member in this type structure. In order to research shear lag and effective flange width of T-shaped short leg shear walls, firstly, the longitudinal displacements were simplified as the combination of shear lag warping displacement, plane section bending displacement and longitudinal displacement induced by axial force. The additional deflection caused by shear lag effect was chosen as the generalized displacement, and quadratic parabola function was assumed as shear lag warping displacement. The principle of minimum potential energy was used to establish the computational theory of normal stress and deflection, meanwhile, the corresponding computational theories whose shear lag warping displacements were cubic and quartic parabola functions were both proposed respectively. Then, with numerical examples, the calculated values and FEM values of the flange normal stresses and deflections were compared. At last, based on the computational theory of normal stress, the computational theory of effective flange width was proposed. Moreover, the effective flange width was used to establish the computational theory of cracking load, and its accuracy was validated by the relevant experiments. Studies indicate that as for the flange normal stresses and deflections of each numerical example, the calculated values have a good agreement with FEM values; as for the cracking loads, the calculated values and the experiment values are in a good agreement.

Characterization of the dynamic heterogeneity during polymer flooding in reservoirs with stratified non-communicating layers

Abstract: Heterogeneity affects the development performance greatly and, therefore, is an important property of the reservoir. The conventional method mainly takes permeability, which often does not change during the production process as the characterization parameter of heterogeneity. However, in polymer flooding, the injected polymer is more likely to enter the high-permeability zone with low resistance, which leads to the decrease of the resistance difference between the high and lowpermeability zones. This non-uniform resistance due to the unbalanced distribution of polymer solution changes the heterogeneity of the reservoir dynamically, and it cannot be reflected by the current representation method. In this paper, a new parameter called “motivation coefficient” (IP ) is proposed, in which not only is the static permeability included, but also the dynamic parameters related with polymer property are taken into consideration, and the Gini coefficient of IP (GCIP ) is selected to represent the dynamic heterogeneity during polymer flooding. Then physical experiment and numerical simulations are done to study the variation law of dynamic heterogeneity during the polymer flooding. The results show that the dynamic heterogeneity is greatly improved after polymer injection. However, at the subsequent water flooding stage, the dynamic heterogeneity is more intensified when the whole polymer flooding process is over. Comprehensively considering the dynamic heterogeneity and development performance, the most favorable value of Gini coefficient of permeability is 0.6, and the best range of polymer concentration is from 0.1% to 0.15%. As for the slug size, large sizes are preferred if they are economically viable.

Spacecraft Chaotic Attitude Control with Certain Actuator Failure Based on Integral Sliding Mode

Abstract: This paper investigates the control problem of spacecraft chaotic attitude motion with certain actuator failure and control input constraint. First, the spacecraft chaotic attitude system is written in nonlinear equation form of three input. When failure of one actuator or failures of two actuators exist, it can be transformed into nonlinear equation form of double input or single input, respectively. To satisfy task-requirement, trajectory planning is performed in advance, and the dynamics equation of angular velocity error can be obtained. Then, integral sliding mode ideas are incorporated into the controller, which consists of equivalent control term and switching control term. Finally, simulations are performed to assess the performance of the proposed controller. The simulation results indicate that the controller has the following characteristics: (a) elimination of chaotic attitude motion, (b) explicit consideration of control input constraint, (c) presupposition of attitude stabilization time, (d) track reference angular velocity trajectory designed in advance, (e) consideration of certain actuator failure, (f) robustness to bigger external disturbance torque.

Pedestrian Traffic Light Detection in Complex Scene Using Adaboost with Multi-layer Features

Abstract: In order to improve the accuracy of the pedestrian traffic light detection in complex scene, an image detection method using AdaBoost with multi-layer features is proposed. In the proposed method, the multi-layer features are adopted to characterize the pedestrian traffic lights, and the AdaBoost algorithm is used to extract the discriminative multi-layer features automatically. The multi-layer features consist of luminance and chrominance components, in which the luminancelayer features are to grasp the shape information, and the chrominance-layer features are to acquire color information. Based on the numerous features, hundreds of efficient weak classifiers are selected by the AdaBoost algorithm to construct a strong classifier. With the strong classifier, images are scanned in test procedure for detection of pedestrian traffic light. Testing results show that the proposed multi-layer features in the CIELAB color space greatly improve the accuracy of the pedestrian traffic light detection, and the proposed methods result in much better performance than the state-of-the-art machine learning methods.

Thermal processing technologies for biomass conversion to clean fuels

Abstract: Uncertain supplies of oil, climate change and attempts to increase the nation's fossil fuel independence are concerns that have evoked a renewed interest in alternative sources of energy. Biomass is one of the most important of these renewable energy sources. Biomass can be converted to energy in a variety of ways. In the thermochemical conversion technologies, gasification and pyrolysis have attracted compared to combustion, because of high efficiency and high yields. In this paper, we will be discussing substantial techniques and recent progress in combustion, pyrolysis and gasification techniques for the conversion of bioenergy into a effective way of energy, fuel and chemicals.

Performance evaluation of fuzzy DE based node placement in WMN

Abstract: Wireless Mesh Networks (WMNs) have received a greater attention in wireless communication field. The conventional node deployment allows random distribution of mesh routers, which increases the number of mesh routers, and hence the design cost also increases. In order to have an optimal placement of mesh nodes, the node placement problem is considered as an optimization problem. Here, the problem is formulated as a facility location problem. A Fuzzy Differential Evolution (FDE) approach is proposed along with a traffic weight (TW) assignment method for optimal placement of mesh nodes and allotting gateways. Design Cost (DC) and Transmission Cost (TC) are the two minimization objectives, which are solved using the proposed method. The simulation results show that, on average, the DC using FDE approach is minimized 10% compared to TW algorithm, 2.8% less than SA, and 1.2% less than DE methods. A network performance metric called failure rate (FR) and the TC objective are considerably reduced using the FDE based placement. The performance of the network is evaluated with multiple CBR flows, and the simulation results show 10% to 5% increase in the throughput and packet delivery rate compared to the existing approaches.

A brief review of the extraction technologies of azadirachtin, a plant-derived bio-pesticide

Abstract: Due to the increasingly strict requirements of sustainable development and environmental protection, chemical pesticides have been gradually questioned for its damage to the environment and human health; therefore environment-friendly and pollution-free plant-derived pesticides are being paid more and more attention to. Azadirachtin (Azt) is a tetracyclic triterpene compound, which is extracted from the seeds, leaves and bark of plant neem (Meliaceae). As the most potential insect antifeedant and growth disturbance agent, it can be used to innovate different biological pesticides. In this article, the present status and progress of Azt extraction were reviewed and some new technologies were described in detail. The research orientation and prospect of Azt extraction techniques were also discussed.

Constructing a multi-microgrid with the inclusion of renewable energy in Oman's rural power system

Abstract: This paper investigates the possibility of constructing multi-microgrids by interlinking the rural area systems in the Al Wusta governorate of the Sultanate of Oman, which are currently being supplied by diesel generators. It is proposed to enhance the rural system under study by switching off small diesel stations and replacing them with wind turbines. The microgrids formed in this way are then interlinked together to create multi-microgrids. The paper studies the interlinked multi-microgrids under different scenarios; in terms of voltage profiles and power flow using the ETAP software package. This study contributes to the feasibility study of retiring some diesel power plants and using renewable energy resources in rural Oman.

Flexural strength estimation of basalt fiber reinforced fly-ash added gypsum based composites

Abstract: Gypsum and fiber reinforced gypsum-based composites are widely used in many construction projects. Many researches have been conducted on these types of composites; however, there are very limited literature studies focused on the estimation of flexural strength of the fiber reinforced gypsum-based composites. And there is no current study on the mechanical strength estimation of these types of composites. An extensive experimental data covering 275 flexural strength test results with five input parameters (fly-ash, basalt, superplasticizer contents, water to binder ratio and slump values) were utilized for the artificial neural network (ANN) model designation. Effect of each parameters on the flexural strength were carefully analyzed. An empirical formula was developed with the generalization capabilities of the proposed ANN system, as well. Analysis results showed a good agreement between the site and field data. And these highly efficient numerical data can make it possible to predict flexural strength of gypsum-based composites.

Determination of the molecular weight of a novel hydroxy-terminated cyclohexene oxide and epichlorohydrin copolyether

Abstract: Cyclohexene oxide (CHO)-epichlorohydrin (ECH) copolyether is one of the raw materials to synthesize transparent polyurethane. In order to control the performance of product, it requires the determination of molecular weight. But at present, the molecular weight of CHO-ECH copolyether has not been reported. Therefore, in this paper, the molecular weight and constant K and α of the solution system was determinated by viscosity method based on Mark-Houwink empirical equation and intrinsic viscosity. This method provides a theoretical basis for the determination of molecular weight of polyether polyols.