Search results for: Mostafa Ghasemi

Authors: E. Ghasemi Ardi, K. J. Dong, A. B. Yu, R. Y. Yang

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In current work, a numerical model based on the discrete element method (DEM) was developed which provided information about particle dynamic and impact event condition inside a laboratory scale impact mill (Fritsch). It showed that each particle mostly experiences three impacts inside the mill. While the first impact frequently happens at front surface of the rotor’s rib, the frequent location of the second impact is side surfaces of the rotor’s rib. It was also showed that while the first impact happens at small impact angle mostly varying around 35º, the second impact happens at around 70º which is close to normal impact condition. Also analyzing impact energy revealed that varying mill speed from 6000 to 14000 rpm, the ratio of first impact’s average impact energy and minimum required energy to break particle (Wₘᵢₙ) increased from 0.30 to 0.85. Moreover, it was seen that second impact poses intense impact energy on particle which can be considered as the main cause of particle splitting. Finally, obtained information from DEM simulation along with obtained data from conducted experiments was implemented in semi-empirical equations in order to find selection and breakage functions. Then, using a back-calculation approach, those parameters were used to predict the PSDs of ground particles under different impact energies. Results were compared with experiment results and showed reasonable accuracy and prediction ability.

Keywords: single particle breakage, particle dynamic, population balance model, particle size distribution, discrete element method

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Authors: M. R. Ghasemi, R. Ghiasi, H. Varaee

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Surrogate model has received increasing attention for use in detecting damage of structures based on vibration modal parameters. However, uncertainties existing in the measured vibration data may lead to false or unreliable output result from such model. In this study, an efficient approach based on Monte Carlo simulation is proposed to take into account the effect of uncertainties in developing a surrogate model. The probability of damage existence (PDE) is calculated based on the probability density function of the existence of undamaged and damaged states. The kriging technique allows one to genuinely quantify the surrogate error, therefore it is chosen as metamodeling technique. Enhanced version of ideal gas molecular movement (EIGMM) algorithm is used as main algorithm for model updating. The developed approach is applied to detect simulated damage in numerical models of 72-bar space truss and 120-bar dome truss. The simulation results show the proposed method can perform well in probability-based damage detection of structures with less computational effort compared to direct finite element model.

Keywords: probability-based damage detection (PBDD), Kriging, surrogate modeling, uncertainty quantification, artificial intelligence, enhanced ideal gas molecular movement (EIGMM)

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Authors: Hagar Ezzat, Mostafa Attia, Ahmed Bedeir, Abdelrazek Elnagger, Matija Strlic

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Ethnographic Museum in Cairo- Egypt is a place of valuable collections (manuscripts, paintings, textiles and other ethnographic materials), the museum experiences serious neglecting with unacceptable display and storage conditions, the museum is located in Tahrir sq., which consider a high traffic area where pollution levels exceed the acceptable levels in museums. The materials used in manufacturing the display cases are expected to be source of many pollutants which affecting the sensitive oil paintings objects in the galleries. 24 diffusion tubes (12 No2, So2 & 12 O3) have been used in "winter 2014 and spring 2014" for monitoring museum environment with three cases "outdoor & indoor and in the gallery display". A series of analytical techniques with scientific tools: Ion Chromatography have been used to assess measurements and effects of gas pollutants on the museum which help us to make good assessment for the damage of oil paintings objects and the condition of the museum and understand the effect of the museum environment on the deterioration of the sensitive oil paintings.

Keywords: environment, museum, paintings, ethnographic, conservation

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Authors: Alaa Mostafa, Samuel Dagogo-Jack, Vivian Thieu, Maria Yu, Nan Zhang, Dara Schuster, Luis-Emilio Garcia-Perez

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Dulaglutide (DU), a once-weekly glucagon-like peptide-1 receptor agonist, was studied in the AWARD clinical trial program in adult patients with type 2 diabetes (T2D) and demonstrated significant hemoglobin A1c (A1c) reduction and potential for weight loss. To evaluate the efficacy and safety of DU 1.5 mg and DU 0.75 mg in patients with T2D by baseline A1c <8.5% or ≥8.5%, a post-hoc analysis was conducted on AWARD-1 to -6 and -8 at 6 months. Across 7 studies, 55% to 82% of the DU-treated patients had a baseline A1c <8.5%, and 18% to 45% had a baseline A1c ≥8.5%. The ranges of A1c reductions with baseline A1c <8.5% and ≥8.5%, respectively, were: DU 1.5 mg: -0.67% to -1.25% and -1.22% to -2.37%; DU 0.75 mg: -0.53% to -1.07% and -1.37% to -2.19%. The A1c reduction from the pooled analysis was greater in patients with baseline A1c ≥8.5% than patients with baseline A1c <8.5%, respectively: DU 1.5 mg: -1.86% and -1.02%; DU 0.75 mg: -1.75% and -0.83%. DU treatments were well tolerated among baseline A1c subgroups. Across the AWARD program, DU 1.5 mg and DU 0.75 mg demonstrated significant A1c reduction in both subgroups with an acceptable safety profile. Compared to patients with baseline A1c <8.5%, patients with baseline A1c ≥8.5% had greater A1c reduction. Disclosures: This study was supported and conducted by Eli Lilly and Company, Indianapolis, IN, USA.

Keywords: A1c reduction, dulaglutide, type 2 diabetes, weight loss

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Authors: Mostafa Makrahy, Nouby Ghazaly, Ahmad Moaaz

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Brakes are one of the most important safety and performance components in automobiles and airplanes. Development of brakes has mainly focused on increasing braking power and stability. Nowadays, brake noise, vibration and harshness (NVH) together with brake dust emission and pad life are very important to vehicle drivers. The main objective of this research is to define the relationship between compressibility of friction materials and their tendency to generate vibration. An experimental study of the friction-induced vibration obtained by the disc brake system of a passenger car is conducted. Three commercial brake pad materials from different manufacturers are tested and evaluated under various brake conditions against cast iron disc brake. First of all, compressibility test for the brake friction material are measured for each pad. Then, brake dynamometer is used to simulate and reproduce actual vehicle braking conditions. Finally, a comparison between the three pad specimens is conducted. The results showed that compressibility have a very significant effect on reduction the vibration occurrence.

Keywords: automotive brake, friction material, brake dynamometer, compressibility test

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Authors: Babak Dizangian, Mohammad Reza Ghasemi, Akram Ghalandari

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Moment frames have considerable ductility against cyclic lateral loads and displacements; however, if this feature causes the relative displacement to exceed the permissible limit, it can impose unfavorable hysteretic behavior on the frame. Therefore, adding a bracing system with the capability of preserving the capacity of high energy absorption and controlling displacements without a considerable increase in the stiffness is quite important. This paper investigates the retrofitting of a single storey steel moment frame through a delayed wire-rope bracing system using a middle steel plate. In this model, the steel plate lies where the wire ropes meet, and the model geometry is such that the cables are continuously under tension so that they can take the most advantage of the inherent potential they have in tolerating tensile stress. Using the steel plate also reduces the system stiffness considerably compared to cross bracing systems and preserves the ductile frame’s energy absorption capacity. In this research, the software models of delayed wire-rope bracing system have been studied, validated, and compared with other researchers’ laboratory test results.

Keywords: cyclic loading, delayed wire rope bracing, ductile moment frame, energy absorption, hysteresis curve

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Authors: Mostafa Solati

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Objectives: Considering the gap of information regarding the optimal antimicrobial efficacy of metronidazole for application in the implant screw hole, this study aimed to compare the antimicrobial efficacy of 0.75% metronidazole and 2% chlorhexidine (CHX) gel applied in the implant screw hole. Materials and Methods: This randomized controlled clinical trial evaluated 60 implants (20 patients, each requiring three implants) in three groups (n=20). In group 1, 0.75% metronidazole gel was applied to the implant screw hole. In group 2, 2% CHX gel was applied, and in group 3, no material was used. Microbial samples were collected from the screw holes after three months, and the microbial colonies were counted. Data were analyzed using ANOVA. Results: The number of bacteria in the control group was significantly higher than that in 0.75% metronidazole gel and 2% CHX groups (P<0.05). The CHX group caused the maximum reduction in colony count with no significant difference from the metronidazole group (P>0.05). Conclusion: The application of 0.75% metronidazole gel and 2% CHX can effectively decrease the colony count in the implant screw hole and can probably play a role in the preservation of peri-implant tissue health.

Keywords: dental implant, metronidazole, CHX, screw hole

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Authors: Mohamed Mokhtar, Mostafa F. Shaaban

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Among the challenges facing solar photovoltaic (PV) systems in the United Arab Emirates (UAE), dust accumulation on solar panels is considered the most severe problem that faces the growth of solar power plants. The accumulation of dust on the solar panels significantly degrades output from these panels. Hence, solar PV panels have to be cleaned manually or using costly automated cleaning methods. This paper focuses on initiating cleaning actions when required to reduce maintenance costs. The cleaning actions are triggered only when the dust level exceeds a threshold value. The amount of dust accumulated on the PV panels is estimated using an artificial neural network (ANN). Experiments are conducted to collect the required data, which are used in the training of the ANN model. Then, this ANN model will be fed by the output power from solar panels, ambient temperature, and solar irradiance, and thus, it will be able to estimate the amount of dust accumulated on solar panels at these conditions. The model was tested on different case studies to confirm the accuracy of the developed model.

Keywords: machine learning, dust, PV panels, renewable energy

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Authors: Mostafa M. Rady, Majed M. Howladar, Saad M. Howladar

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A field trial was conducted during two successive seasons (2013 and 2014) in Southeast Fayoum, Egypt (29º 17'N; 30º 53'E) to investigate the improving effect of ascorbic acid (Vit C) foliar spray at the rates of 0, 1, 2 or 3 mM on the growth, seed and oil yields, and some chemical constituents of sunflower plants grown on a reclaimed saline soil (EC = 7.98–7.83). Vit C application at all rates (1, 2 and 3 mM) was significantly increased growth traits, seed and oil yields, and the concentrations of endogenous Vit C, leaf photosynthetic pigments, total soluble sugars, free proline and nutrient elements as well as K/Na ratio. In contrast, Na concentration was significantly reduced with the application of all Vit C levels. Vit C foliar spray at the rate of 2 mM was found to be the best treatment, alleviating the inhibitory effects of salinity on sunflower plants grown on a reclaimed saline soil.

Keywords: Helianthus annuus L., Vit C, salinity, growth, seed and oil yields, osmoprotectants

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Authors: Ehsan Etesami, Mostafa Noroozi

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Thalassiosira weissflogii with proper size and nutrition value specially PUFA n-3 has been widely used in bivalve shellfish larviculture and shrimp industries. This diatom was isolated from Caspian Sea and identified with morphology and molecular characters. T. weissflogii was cultivated in normal and nitrogen deficiency F2 medium during 18 to 30 days, in addition, the growth indices, total lipid, and EPA-DHA content were elucidated. The growth indices of the cells decreased during the stress experiments while the total lipid levels increased during prolonged culturing (30 days). The maximum level of C20:5 was calculated as 8.8 (%TFA) in normal condition during 30 days; however, the combination of N- deficiency condition with prolonged culturing led to the increase of the level of C22:6 from 3.5 to 12.63 (%TFA). The concept of N-deficiency along with prolonged culturing of Thalassiosira weissflogii can improve PUFA n-3 content in order to use in shellfish and shrimp industries.

Keywords: DHA, Thalassiosira weissflogii, nitrogen deficiency, EPA, fatty acids, aquafeed

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Authors: Hamed Saremi, Suzan Taghavy, Seyed Mohammad Hanif Sanjari, Mostafa Kahali

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One of the challenges in manufacturing and service companies to provide a product or service is recognized Brand to consumers in target markets. They provide most of their processes under the same capacity. But the constant threat of devastating internal and external resources to prevent a rise Brands and more companies are recognizing the stages are bankrupt. This paper has tried to identify and analyze effective indicators of brand equity and focuses on indicators and presents a model of intelligent create a model to prevent possible damage. In this study, the identified indicators of brand equity are based on literature study and according to expert opinions, set of indicators By techniques DEMATEL Then to used Multi-Step Adaptive Neural-Fuzzy Inference system (ANFIS) to design a multi-stage intelligent system for assessment of brand equity.

Keywords: brand, cosmetic product, ANFIS, DEMATEL

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Authors: M. Gholinjad Kordan, M. Ghasemi, S. Fazelifar

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Aim: liver plays a role in an astounding number of bodily functions: it helps with blood sugar regulation; metabolizes hormones; and traps and breaks down bacteria and toxins. Unfortunately, bodily demands can overwhelm your liver. Massage therapy can help by restoring healthy circulation and speeding the elimination of toxins. Apium graveolens has antioxidant property because of its flavonoid compounds. The purpose of this study was to determine Effect of massage and graveolens consumption on liver markers in women. Methodology: forty non-athlete male students were randomly divided into four groups: 1-control, 2-massage, 3-massage and graveolens and 4-graveolens. Amount of 5cc Blood sampling were obtained pre-test and post-test (after 12 weeks). Subjects received Russian massage for 8 weeks and 3 days a week for 20 minutes. Also, Complementary groups received the capsule supplement of graveolens after eating for twelve weeks and three times a day. Data was analyzed with One way ANOVA and tukey in p < 0/05. Results: Based on research findings, twelve weeks massage and graveolens consumption lead to a significant decrease in enzymes activity of ALT, AST and ALP in sedentary women. Conclusion: Results of This study shows that massage or graveolens consumption and especially combination of both can be used as desirable threpatic method in order to reduce or improve symptoms caused by excess weight, especially the liver damage.

Keywords: massage, graveolens, liver markers, sedentary women

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Authors: Mostafa ‘Neo’ Mohsenvand, Mohammad Rasool Izadi, Pattie Maes

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EEG-based biometrics (user identification) has been explored on small datasets of no more than 157 subjects. Here we show that the accuracy of modern supervised methods falls rapidly as the number of users increases to a few thousand. Moreover, supervised methods require a large amount of labeled data for training which limits their applications in real-world scenarios where acquiring data for training should not take more than a few minutes. We show that using contrastive learning for pre-training, it is possible to maintain high accuracy on a dataset of 2130 subjects while only using a fraction of labels. We compare 5 different self-supervised tasks for pre-training of the encoder where our proposed method achieves the accuracy of 96.4%, improving the baseline supervised models by 22.75% and the competing self-supervised model by 3.93%. We also study the effects of the length of the signal and the number of channels on the accuracy of the user-identification models. Our results reveal that signals from temporal and frontal channels contain more identifying features compared to other channels.

Keywords: brainprint, contrastive learning, electroencephalo-gram, self-supervised learning, user identification

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Authors: A. Mostafa

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This paper presents a numerical study on determination of ballistic limit velocity (V₅₀) of stainless steel 304 (SS 304) used in manufacturing security screens. The simulated ballistic impact tests were conducted on clamped sheets with different thicknesses using ABAQUS/Explicit nonlinear finite element (FE) package. The ballistic limit velocity was determined using three approaches, namely: numerical tests based on material properties, FE calculated residual velocities and FE calculated residual energies. Johnson-Cook plasticity and failure criterion were utilized to simulate the dynamic behaviour of the SS 304 under various strain rates, while the well-known Lambert-Jonas equation was used for the data regression for the residual velocity and energy model. Good agreement between the investigated numerical methods was achieved. Additionally, the dependence of the ballistic limit velocity on the sheet thickness was observed. The proposed approaches present viable and cost-effective assessment methods of the ballistic performance of SS 304, which will support the development of robust security screen systems.

Keywords: ballistic velocity, stainless steel, numerical approaches, security screen

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Authors: Sayed Kifayat Shah, Tang Zhongjun, Mohammad Ahmad, Sohaib Mostafa

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This article investigates consumer’s intention to shift to 5G in the light of disruptive technology innovation. To switch from 4G (Existing) technology to 5G (Disruptive) technology requires not just economic benefits and costs but involves other values too, which aren't yet experienced in the framework of technology innovation. This study extended the valued adaptation (VAM) model by proposing the sustainability values (SVs) construct. The model was examined on data from 361 Chinese consumers using the partial least squares-based structural equation modelling (PLS-SEM) technique. The outcomes prove the significant correlation of sustainability values (SVs) which influences consumer’s switching intentions toward 5G disruptive technology. The findings of this research will be helpful to telecoms firms in developing consumer retention strategies. Some limitations and the importance of the research for scholars and managers are also discussed.

Keywords: value adaptation model (VAM), sustainability values (SVs), disruptive 5G technology, switching intentions (SI), partial least squares-based structural equation modelling (PLS-SEM)

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Authors: Sahar B. Ahmed, M. Mostafa Said, Mona I. Mohamed

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Streptozotocin (STZ) caused a significant increase in blood glucose and malondialdehyde (MDA) levels in serum accompanied by a significant decrease in blood reduced glutathione (GSH) and superoxide dismutase (SOD) activities. Also, ALT, AST, albumin and urea were markedly affected by STZ injection. The oral administration of Mango leaves extract (MLE) one hour before STZ injection was significantly improved the blood glucose level, ALT, AST activities, albumin and urea that associated with the regulation of MDA, GSH and SOD levels. The antimicrobial activity of MLE showed a significant inhibitory activity against multidrug resistant gram positive and gram negative bacteria isolated from patients in Egyptian hospitals especially Salmonella typhi and typhimurium. In conclusion, results revealed the antioxidant, hypoglycemic effect and antimicrobial potentials of MLE under investigation. Further studies will be needed to investigate the prolonged period of MLE administration and its possible side effects.

Keywords: aqueous extract of mango leaves, STZ, antioxidant, hypoglycemic effect, antimicrobial potentials.

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Authors: Amir Mohammad Fathollahi Fard, Mostafa Hajiaghaei-Keshteli, Mohammad Mahdi Paydar

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With increasing life expectancy in developed countries, the role of home care services is highlighted by both academia and industrial contributors in Home Health Care Supply Chain (HHCSC) companies. The main decisions in such supply chain systems are the location of pharmacies, the allocation of patients to these pharmacies and also the routing and scheduling decisions of nurses to visit their patients. In this study, for the first time, an integrated model is proposed to consist of all preliminary and necessary decisions in these companies, namely, location-allocation-routing model. This model is a type of NP-hard one. Therefore, an Imperialist Competitive Algorithm (ICA) is utilized to solve the model, especially in large sizes. Results confirm the efficiency of the developed model for HHCSC companies as well as the performance of employed ICA.

Keywords: home health care supply chain, location-allocation-routing problem, imperialist competitive algorithm, optimization

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Authors: Yasin Ghasemi-Zadeh, Yousef Kavian

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Wireless body area networks (WBANs) technology has achieved lots of popularity over the last decade with a wide range of medical applications. This paper presents an asynchronous media access control (MAC) protocol based on B-MAC protocol by giving an application for medical issues. In WBAN applications, there are some serious problems such as energy, latency, link reliability (quality of wireless link) and throughput which are mainly due to size of sensor networks and human body specifications. To overcome these problems and improving link reliability, we concentrated on MAC layer that supports mobility models for medical applications. In the presented protocol, preamble frames are divided into some sub-frames considering the threshold level. Actually, the main reason for creating shorter preambles is the link reliability where due to some reasons such as water, the body signals are affected on some frequency bands and causes fading and shadowing on signals, therefore by increasing the link reliability, these effects are reduced. In case of mobility model, we use MoBAN model and modify that for some more areas. The presented asynchronous MAC protocol is modeled by OMNeT++ simulator. The results demonstrate increasing the link reliability comparing to B-MAC protocol where the packet reception ratio (PRR) is 92% also covers more mobility areas than MoBAN protocol.

Keywords: wireless body area networks (WBANs), MAC protocol, link reliability, mobility, biomedical

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Authors: Hamida Y. Mostafa, Ghada E. Khedr, Dina M. Abd El-Aty

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Sulfur compound removal from petroleum fractions is a critical component of environmental protection demands. Solvent extraction, oxidative desulfurization, or hydro-treatment techniques have traditionally been used as the removal processes. While all methods were capable of eliminating sulfur compounds at moderate rates, they had some limitations. A major problem with these routes is their high running expenses, which are caused by their prolonged operation times and high energy consumption. Therefore, new methods for removing sulfur are still necessary. In the current study, a simple assisted desulfurization system for gas oil fraction has been successfully developed using acetonitrile and methanol as a solvent under microwave irradiation. The key variables affecting sulfur removal have been studied, including microwave power, irradiation time, and solvent to gas oil volume ratio. At the conclusion of the research that is being presented, promising results have been found. The results show that a microwave-assisted extractive desulfurization method had remove sulfur with a high degree of efficiency under the suitable conditions.

Keywords: extractive desulfurization, microwave assisted extraction, petroleum fractions, acetonitrile and methanol

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Authors: Borzou Faramarzi, Farideh Azimi, Azam Gohardoust, Abbas Ghasemi Ghasemvand, Maryam Mirzaei, Mandana Amani

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In this study, attempts were made to examine and analyze the trend for rainfall changes in Kangan City, Booshehr Province, during the time span 1964 to 2003, using seven rainfall threshold indices based on 50 climate extremes indices approved by WMO–CCL/CLIVAR. These indices include days with heavy precipitations, days with rainfalls, frequency of rainfall threshold values, intensity of rainfall threshold values, percentage of rainfall threshold values, successive days of rainfall, and successive days with no precipitation. Results are indicative of the fact that Kangan City climatic conditions have become more dried than before. Indices days with heavy precipitations and days with rainfalls do not show a certain trend in Kangan City. Frequency, intensity, and percentage of rainfall threshold values in the station under investigation do not indicate a certain trend. In analysis of time series of rainfall extreme indices, generally, it was revealed that Kangan City is influenced by general factors of global warming. Calculation of values for the next 10 years based on ARIMA models demonstrates a continuation of warming trends in Kangan City. On the whole, rainfall conditions in Kangan City have experienced more dry periods compared to the past, the trend which is also observable for next 10 years.

Keywords: climatic indices, climate change, extreme temperature and precipitation, time series

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Authors: Khaled A. Madi, Rema A. Mousbahi, Mostafa B. Abuitbel, Abdualhakim O. Nagi

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Antenna perhaps is the most important part of any communication system, it determines the overall efficiency and the direction of radiation of the system. Antennas vary in shape and size on a very wide range. For fast moving vehicles, the antenna should offer as litter aerodynamic resistance as possible. Slot antenna is best suited for this purpose. It offers very little aerodynamic resistance, compact, easy to feed and fabricate. This work presented in this paper deals with the investigation of a half wave slot antenna. The antenna has been studied, analyzed, designed, simulated, fabrication, and tested at the X-band. The field of antenna study is an extremely vast one, and to grasp the fundamentals, two pronged approaches have been used, and the focus was on the fabrication and testing of a slot waveguide directional antenna. Focuses on the design and simulation of slot antennas with an emphasis on optimization of a 9.1 GHz a rectangular waveguide have been used to feed slot antenna. A microwave fed slot antenna used in the communication lab was also simulated. The results have been presented and compared with the expected values, where a good agreement was achieved between the simulation and experimental results.

Keywords: microwave, slot antenna, simulation, fabrication

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Authors: Mostafa M. Makrahy, Nouby M. Ghazaly, G. T. Abd el-Jaber

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This paper presents the experimental study of vibration generated by friction materials of an automotive disc brake system using brake test rig. Effects of silica sand particles which are available on the road surface as an environmental condition with a size varied from 150 μm to 600 μm are evaluated. Also, the vibration of the brake disc is examined against the friction material in humidity environment conditions under variable rotational speed. The experimental results showed that the silica sand particles have significant contribution on the value of vibration amplitude which enhances with increasing the size of silica sand particles at different speed conditions. Also, it is noticed that the friction material is sensitive to humidity and the vibration magnitude increases under wet testing conditions. Moreover, it can be reported that with increasing the applied pressure and rotational speed of the braking system, the vibration amplitudes decrease for all cases.

Keywords: disc brake vibration, friction-induced vibration, silica sand particles, brake operational and environmental conditions

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Authors: Mehrji Khosravan, Mostafa Fathali-Sianib, Davood Soudbar, Sasan Talebnezhad, Mohammad-Reza Ebrahimi

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The late transition metal catalyst of the end group of transition metals in the periodic table as Ni, Fe, Co, and Pd was grown up rapidly in polyolefin industries recently. These metals with suitable ligands exhibited special characteristic properties and appropriate activities in the production of polyolefins. The ligand 1,4-bis (2,6-diisopropyl phenyl) acenaphthene was synthesized by reaction of 2,6-diisopropyl aniline and acenaphthenequinone. The ligand was added to nickel (II) dibromide salt for synthesis the 1,4-bis (2,6 diisopropylphenyl) acenaphthene nickel (II) dibromide catalyst. The structure of the ligand characterized by IR technique. The catalyst then deposited on graphene and graphene oxide by vander walss-attachment for use in Ethylene slurry polymerization process in the presence of catalyst activator such as methylaluminoxane (MAO) in hexane solvent. The structure of the catalyst characterized by IR and TEM techniques and some of the polymers were characterized by DSC. The highest activity was achieved at 600 C for catalyst.

Keywords: α-diimine nickel (II) complex, graphene as supported catalyst, late transition metal, ethylene polymerization

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Authors: Mohammed Amraouy, Mostafa Bellafkih, Abdellah Bennane, Aziza Benomar

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Distance education has become popular due to their ability to provide learning from almost anywhere and anytime. COVID-19 forced educational institutions to urgently introduce distance education to ensure pedagogical continuity, so all stakeholders were invited to adapt to this new paradigm. In order to identify strengths and weaknesses, the research focuses on the need to create an effective mechanism for evaluating distance education. The aims of this research were to explore and evaluate the use of digital media in general and official platforms in particular in distance education practices. To this end, we have developed and validated a questionnaire before administering it to a sample of 431 teachers in Morocco. Teachers reported lower knowledge and skills in the didactic use of ICT in the distance education process. In addition, although age and educative experience of the teachers continue to modulate the level of instrumental skills. Therefore, resources (digital resources and infrastructure) and the teachers’ ICT training present serious limitations, which require a training more focused on the distance educational paradigm and educational environments that allow teachers to create educational activities able to promote and facilitate the distance learning process.

Keywords: distance education, e-learning, teachers’ perceptions, assessment

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Authors: Sahar Heidary, Ramin Ghasemi Shayan

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The overall goal Monte Carlo N-atom radioactivity transference PC program (MCNP4C) was done for the regeneration of x-ray groups in diagnostic radiology and mammography. The electrons were transported till they slow down and stopover in the target. Both bremsstrahlung and characteristic x-ray creation were measured in this study. In this issue, the x-ray spectra forecast by several computational models recycled in the diagnostic radiology and mammography energy kind have been calculated by appraisal with dignified spectra and their outcome on the scheming of absorbed dose and effective dose (ED) told to the adult ORNL hermaphroditic phantom quantified. This comprises practical models (TASMIP and MASMIP), semi-practical models (X-rayb&m, X-raytbc, XCOMP, IPEM, Tucker et al., and Blough et al.), and Monte Carlo modeling (EGS4, ITS3.0, and MCNP4C). Images got consuming synchrotron radiation (SR) and both screen-film and the CR system were related with images of the similar trials attained with digital mammography equipment. In sight of the worthy feature of the effects gained, the CR system was used in two mammographic inspections with SR. For separately mammography unit, the capability acquiesced bilateral mediolateral oblique (MLO) and craniocaudal(CC) mammograms attained in a woman with fatty breasts and a woman with dense breasts. Referees planned the common groups and definite absences that managed to a choice to miscarry the part that formed the scientific imaginings.

Keywords: mammography, monte carlo, effective dose, radiology

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Authors: Mostafa Amirjan

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In the present study, the properties of Al-Al2O3 nanocomposite hollow sphere structures were investigated. For this reason, the Al-based nanocomposite hollow spheres with different amounts of nano alumina reinforcement (0-10wt %) and different ratio of thickness to diameter (t/D: 0.06-0.3) were prepared via a powder metallurgy method. Then, the effect of mentioned parameters was studied on physical and quasi static mechanical properties of their related prepared structures (open/closed cell) such as density, hardness, strength and energy absorption. It was found that as the t/D ratio increases the relative density, compressive strength and energy absorption increase. The highest values of strength and energy absorption were obtained from the specimen with 5 wt. % of nanoparticle reinforcement, t/D of 0.3 (t=1 mm, D=400µm) as 22.88 MPa and 13.24 MJ/m3, respectively. The moderate specific strength of prepared composites in the present study showed the good consistency with the properties of others low carbon steel composite with similar structure.

Keywords: hollow sphere structure foam, nanocomposite, thickness and diameter (t/D ), powder metallurgy

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Authors: Mostafa Jafari

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How the people continually create and recreate the six dimensional inter- sub-cultural relationships from the strategic point of view? Can they engineer and direct it toward creating a set of peaceful subcultures? This paper answers to these questions. Our mental images shape the quantity and quality of our relationships. The six dimensions of mental images are: my mental image about myself, your mental image about yourself, my mental image about you, your mental image about me, my imagination about your image about me and your imagination about my mental image about you. Strategic engineering is dynamically shaping these images and imaginations.Methodology: This survey, which is based on object and the relation between the variables, is explanatory, correlative and quantitative. The target community members are 90 educated people from universities. The data has been collected through questionnaire and interview and has been analyzed by descriptive statistical techniques and qualitative method. Results: Our findings show that engineering and deliberatly managing the process of inter- sub-cultural transactions in the national and global level can enable us to continually reform a peaceful set of learner sub-culturals toward recreate a peaceful unit global Home.

Keywords: strategic engineering, mental image, six dimensional mental images strategy , cultural literacy, radar technique

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Authors: Shirin Jalili, Ramin Ghasemi

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Lumbar microdiscectomy is the most commonly performed spinal surgery strategy; it is regularly performed to lighten the indications and signs of sciatica within the lower back and leg caused by a lumbar disc herniation. This surgery aims to progress leg pain, reestablish function, and enable a return to ordinary day-by-day exercises. Rates of lumbar disc surgery show critical geographic varieties recommending changing treatment criteria among working specialists. Few population-based considers have investigated the hazard of reoperation after disc surgery, and regional or inter specialty varieties within the reoperations are obscure. The conventional approach to recouping from lumbar microdiscectomy has been to restrain bending, lifting, or turning for a least 6 weeks in arrange to anticipate the disc from herniating once more. Traditionally, patients were exhorted to limit post-operative action, which was accepted to decrease the hazard of disc herniation and progressive insecurity. In modern hone, numerous specialists don't limit understanding of postoperative action due to the discernment this practice is pointless. There's a need of thinks about highlighting the result by distinctive scores or parameters after surgery for repetitive circle herniations of the lumbar spine at the starting herniation location. This study will evaluate the quality of life after surgical treatment of recurrent herniations with distinctive standardized approved result instruments.

Keywords: post-operative activity, disc, quality of life, treatment, movements

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Authors: Mostafa Kazemi, Zahra N. Farkhani

Abstract:

This paper proposes an integrated Data Envelopment Analysis (DEA) and Variance Inflation Factor (VIF) model for measuring the technical efficiency of decision making units. The model is validated using a set of 69% sales representatives’ dairy products. The analysis is done in two stages, in the first stage, VIF technique is used to distinguish independent effective factors of resellers, and in the second stage we used DEA for measuring efficiency for both constant and variable return to scales status. Further DEA is used to examine the utilization of environmental factors on efficiency. Results of this paper indicated an average managerial efficiency of 83% in the whole sales representatives’ dairy products. In addition, technical and scale efficiency were counted 96% and 80% respectively. 38% of sales representative have the technical efficiency of 100% and 72% of the sales representative in terms of managerial efficiency are quite efficient.High levels of relative efficiency indicate a good condition for sales representative efficiency.

Keywords: data envelopment analysis (DEA), relative efficiency, sales representatives’ dairy products, variance inflation factor (VIF)

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Authors: Elnaz Lalezari, Ramin Ghasemi Shaya

Abstract:

The birth way is influenced by a fracture within the quiet care handle, making a brokenness of this final one. The pregnant lady has got to interface with numerous experts, both amid the pregnancy, the childbirth, and the puerperium. Be that as it may, amid the final ten a long time, there has been an expanding of the pregnancy care worked by the midwife, who is considered to be the administrator with the correct competences, who can beware of each pregnancy and may profit herself of other professionals' commitments in arrange to make strides the results of maternal and neonatal health. To confirm whether there are proofs of viability that bolster the caseload birthing assistance care show, and in case it is conceivable to apply this show within the birth way in Italy. A amendment of writing has been done utilizing a few look motor (Google, Bing) and particular databases (MEDLINE, CINAHL, Embase, Domestic - ClinicalTrials.gov). There has, too, been a discussion of the Italian directions, the national rules, and the proposals of WHO. Results: The look string, legitimately adjusted to the three databases, has given the taking after comes about: MEDLINE 64 articles, CINAHL 94 articles, Embase 88 articles. From this choice, 14 articles have been extricated: 1 orderly survey, 3 controlled arbitrary trial, 7 observational ponders, 3 subjective studies. The caseload maternity care appears to be an successful and dependable organisational/caring strategy. It reacts to the criterions of quality and security, to the requirements of ladies not as it were amid the pregnancy but moreover amid the post-partum stage. For these reasons, it appears exceptionally valuable also for the birth way within the Italian reality.

Keywords: midwifery, care, caseload, maternity

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