Search results for: Mohammad Jafarian
1387 Necessary Condition to Utilize Adaptive Control in Wind Turbine Systems to Improve Power System Stability
Authors: Javad Taherahmadi, Mohammad Jafarian, Mohammad Naser Asefi
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The global capacity of wind power has dramatically increased in recent years. Therefore, improving the technology of wind turbines to take different advantages of this enormous potential in the power grid, could be interesting subject for scientists. The doubly-fed induction generator (DFIG) wind turbine is a popular system due to its many advantages such as the improved power quality, high energy efficiency and controllability, etc. With an increase in wind power penetration in the network and with regard to the flexible control of wind turbines, the use of wind turbine systems to improve the dynamic stability of power systems has been of significance importance for researchers. Subsynchronous oscillations are one of the important issues in the stability of power systems. Damping subsynchronous oscillations by using wind turbines has been studied in various research efforts, mainly by adding an auxiliary control loop to the control structure of the wind turbine. In most of the studies, this control loop is composed of linear blocks. In this paper, simple adaptive control is used for this purpose. In order to use an adaptive controller, the convergence of the controller should be verified. Since adaptive control parameters tend to optimum values in order to obtain optimum control performance, using this controller will help the wind turbines to have positive contribution in damping the network subsynchronous oscillations at different wind speeds and system operating points. In this paper, the application of simple adaptive control in DFIG wind turbine systems to improve the dynamic stability of power systems is studied and the essential condition for using this controller is considered. It is also shown that this controller has an insignificant effect on the dynamic stability of the wind turbine, itself.Keywords: almost strictly positive real (ASPR), doubly-fed induction generator (DIFG), simple adaptive control (SAC), subsynchronous oscillations, wind turbine
Procedia PDF Downloads 3771386 Investigating the Post-Liver Transplant Complications and Their Management in Children Referred to the Children’s Medical Center
Authors: Hosein Alimadadi, Fatemeh Farahmand, Ali Jafarian, Nasir Fakhar, Mohammad Hassan Sohouli, Neda Raeesi
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Backgroundsː Regarding the important role of liver transplantation as the only treatment in many cases of end-stage liver disease in children, the aim of this study is to investigate the complications of liver transplantation and their management in children referred to the Children's Medical Center. Methods: This study is a cross-sectional study on pediatric patients who have undergone liver transplants in the years 2016 to 2021. The indication for liver transplantation in this population was confirmed by a pediatric gastroenterologist, and a liver transplant was performed by a transplant surgeon. Finally, information about the patient before and after the transplantation was collected and recorded. Results: A total of 53 patients participated in this study, including 25 (47.2%) boys and 28 (52.8%) girls. The most common causes of liver transplantation were cholestatic and metabolic diseases. The most common early complication of liver transplantation in children was acute cellular rejection (ACR) and anastomotic biliary stricture. The most common late complication in these patients was an infection which was observed in 56.6% of patients. Among the drug side effects, neurotoxicity (convulsions) was seen more in patients, and 15.1% of the transplanted patients died. Conclusion: In this study, the most common early complication of liver transplantation in children was ACR and biliary stricture, and the most common late complication was infection. Neurotoxicity (convulsions) was the most common side effect of drugs.Keywords: liver transplantation, complication, infection, survival rate
Procedia PDF Downloads 831385 The English Translation of Arabic Metaphors in the Holy Qura’n
Authors: Mohammad Hamzah Alshehab
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Metaphor is a substitute expression in everyday life in languages, thoughts and actions. It has an original value in language use with different conceptual, grammatical and properties. In addition, it is a central concept in literary studies. The present paper aims at investigating metaphor’s types imbedded in some Holy Verses (HV). For achieving the objectives of this paper, two English versions were chosen , the first is the Translation of the Meanings of the Noble Qura’n in the English Language by Mohammad AlHilali and Mohammad Khan, and the second version is the English Translation of the Holy Qura’n by Mohammad Ali were used. The researcher selected (20) Holy Verses include metaphors to be analyzed and investigated. Metaphor types were categorized by an assessment of the two translations followed by a discussion between the two versions of translation.Keywords: metaphor, metaphor’s types, Holy Qura’n, Holy Verses
Procedia PDF Downloads 6531384 The Generation of Insulin Producing Cells from Human Mesenchymal Stem Cells by miR-375 and Anti-miR-9
Authors: Arefeh Jafarian, Mohammad Taghikani, Saied Abroun, Amir Allahverdi, Masoud Soleimani
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Introduction: The miRNAs have key roles in control of pancreatic islet development and insulin secretion. In this regards, current study investigated the pancreatic differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) by up-regulation of miR-375 and down-regulation of miR-9 by lentiviruses containing miR-375 and anti-miR-9. Findings: After 21 days of induction, islet-like clusters containing insulin producing cells (IPCs) were confirmed by dithizone (DTZ) staining. The IPCs and β cell specific related genes and proteins were detected using qRT-PCR and immunofluorescence on days 7, 14 and 21 of differentiation. Glucose challenge test was performed at different concentrations of glucose as well as extracellular and intracellular insulin and C-peptide were assayed using ELISA kit. In derived IPCs by miR-375 alone are capable to express insulin and other endocrine specific transcription factors, the cells lack the machinery to respond to glucose. The differentiated hMSCs by miR-375 and anti-miR-9 lentiviruses could secrete insulin and c-peptide in a glucose-regulated manner. Conclusion: It was found that over-expression of miR-375 led to a reduction in levels of Mtpn protein in derived IPCs, while treatment with anti-miR-9 following miR-375 over-expression had synergistic effects on MSCs differentiation and insulin secretion in a glucose-regulated manner. The researchers reported that silencing of miR-9 increased OC-2 protein in IPCs that may contribute to the observed glucose-regulated insulin secretion. These findings highlight miRNAs functions in stem cells differentiation and suggest that they could be used as therapeutic tools for gene-based therapy in diabetes mellitus.Keywords: diabetes, differentiation, MSCs, insulin producing cells, miR-375, miR-9
Procedia PDF Downloads 3171383 Experimental Study of Different Types of Concrete in Uniaxial Compression Test
Authors: Khashayar Jafari, Mostafa Jafarian Abyaneh, Vahab Toufigh
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Polymer concrete (PC) is a distinct concrete with superior characteristics in comparison to ordinary cement concrete. It has become well-known for its applications in thin overlays, floors and precast components. In this investigation, the mechanical properties of PC with different epoxy resin contents, ordinary cement concrete (OCC) and lightweight concrete (LC) have been studied under uniaxial compression test. The study involves five types of concrete, with each type being tested four times. Their complete elastic-plastic behavior was compared with each other through the measurement of volumetric strain during the tests. According to the results, PC showed higher strength, ductility and energy absorption with respect to OCC and LC.Keywords: polymer concrete, ordinary cement concrete, lightweight concrete, uniaxial compression test, volumetric strain
Procedia PDF Downloads 3941382 Refinery Sulfur as an Alternative Agent to Decrease Pesticide Exposure in Pistachio Orchards and Common Pistachio Psylla’s Control
Authors: Mehdi Basirat, Mohammad Rouhani, Shahla Borzouei, Majid Zarangi, Asma Abolghasemi, Mohammad Fazel Soltani, Mohammad Gorji, Mohammad Amin Samih
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The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae), as one of the most detrimental pests in all pistachio producing regions, causes great economic damages to pistachio trees. Nowadays, various pesticides are used to control the common pistachio psylla and robust pesticide exposure has occurred in orchards. In this study, field experiments were conducted during 2018–2021 to assess the effects of sulfur on A. pistaciae. This study compared sulfur with asafoetida extract and pesticide (acetamiprid) on A. pistaciae based on complete randomized blocks with three replications. The analysis results of variance showed that the effect of treatments on egg (F2,24 = 17.61, P = 0.00) and nymphs (F2,24 = 18.29, P = 0.00) had a significant difference at a 1% level. The results demonstrated that sulfur had the highest measure of control on eggs and nymphs significantly compared to the plant extract and pesticide (negative control). These results provide support to the potential use of sulfur as an alternative pest management tool against A. pistaciae. The results clearly indicated that sulfur could control the common pistachio psylla population for six weeks at least.Keywords: Agonoscena pistaciae, pesticide exposure, pistachio, sulfur
Procedia PDF Downloads 1651381 Hybrid Dynamic Approach to Optimize the Impact of Shading Design and Control on Electrical Energy Demand
Authors: T. Parhizkar, H. Jafarian, F. Aramoun, Y. Saboohi
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Applying motorized shades have substantial effect on reducing energy consumption in building sector. Moreover, the combination of motorized shades with lighting systems and PV panels can lead to considerable reduction in the energy demand of buildings. In this paper, a model is developed to assess and find an optimum combination from shade designs, lighting control systems (dimming and on/off) and implementing PV panels in shades point of view. It is worth mentioning that annual saving for all designs is obtained during hourly simulation of lighting, solar heat flux and electricity generation with the use of PV panel. From 12 designs in general, three designs, two lighting control systems and PV panel option is implemented for a case study. The results illustrate that the optimum combination causes a saving potential of 792kW.hr per year.Keywords: motorized shades, daylight, cooling load, shade control, hourly simulation
Procedia PDF Downloads 1711380 Model Updating-Based Approach for Damage Prognosis in Frames via Modal Residual Force
Authors: Gholamreza Ghodrati Amiri, Mojtaba Jafarian Abyaneh, Ali Zare Hosseinzadeh
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This paper presents an effective model updating strategy for damage localization and quantification in frames by defining damage detection problem as an optimization issue. A generalized version of the Modal Residual Force (MRF) is employed for presenting a new damage-sensitive cost function. Then, Grey Wolf Optimization (GWO) algorithm is utilized for solving suggested inverse problem and the global extremums are reported as damage detection results. The applicability of the presented method is investigated by studying different damage patterns on the benchmark problem of the IASC-ASCE, as well as a planar shear frame structure. The obtained results emphasize good performance of the method not only in free-noise cases, but also when the input data are contaminated with different levels of noises.Keywords: frame, grey wolf optimization algorithm, modal residual force, structural damage detection
Procedia PDF Downloads 3891379 Risk Based on Computer Auditing and Measures of Prevention
Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori
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The technology of computer audit played a major role in the progress and prospects of a proper application to improve the quality and efficiency of audit work. But due to the technical complexity and the specific risks of computer audit, it should be shown effective in audit and preventive action. Mainly through research in this paper, we propose the causes of audit risk in a computer environment and the risk of further proposals for measures to control, to some extent reduce the risk of computer audit and improve the audit quality.Keywords: computer auditing, risk, measures to prevent, information management
Procedia PDF Downloads 5261378 Risk-Based Computer Auditing and Measures of Prevention
Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori
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the technology of Computer audit played a major role in the progress and prospects of a proper application to improve the quality and efficiency of audit work. But due to the technical complexity and the specific risks of computer audit, it should be shown effective in audit and preventive action. Mainly through research in this paper, we proposes the causes of audit risk in a computer environment and the risk of further proposals for measures to control, to some extent reduce the risk of computer audit and improve the audit quality.Keywords: computer auditing, risk, measures to prevent, information technology
Procedia PDF Downloads 4891377 Evaluate the Changes in Stress Level Using Facial Thermal Imaging
Authors: Amin Derakhshan, Mohammad Mikaili, Mohammad Ali Khalilzadeh, Amin Mohammadian
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This paper proposes a stress recognition system from multi-modal bio-potential signals. For stress recognition, Support Vector Machines (SVM) and LDA are applied to design the stress classifiers and its characteristics are investigated. Using gathered data under psychological polygraph experiments, the classifiers are trained and tested. The pattern recognition method classifies stressful from non-stressful subjects based on labels which come from polygraph data. The successful classification rate is 96% for 12 subjects. It means that facial thermal imaging due to its non-contact advantage could be a remarkable alternative for psycho-physiological methods.Keywords: stress, thermal imaging, face, SVM, polygraph
Procedia PDF Downloads 4871376 Flood Scenarios for Hydrological and Hydrodynamic Modelling
Authors: M. Sharif Imam Ibne Amir, Mohammad Masud Kamal Khan, Mohammad Golam Rasul, Raj H. Sharma, Fatema Akram
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Future flood can be predicted using the probable maximum flood (PMF). PMF is calculated using the historical discharge or rainfall data considering the other climatic parameter stationary. However, climate is changing globally and the key climatic variables are temperature, evaporation, rainfall and sea level rise (SLR). To develop scenarios to a basin or catchment scale these important climatic variables should be considered. Nowadays scenario based on climatic variables is more suitable than PMF. Six scenarios were developed for a large Fitzroy basin and presented in this paper.Keywords: climate change, rainfall, potential evaporation, scenario, sea level rise (SLR), sub-catchment
Procedia PDF Downloads 5311375 Modern Literary Authors and Samuel Beckett's Trace of Lost Self in Modernity
Authors: Mohammad Mehdi Mazaheri, Mohammad Motiee Lahromi
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In a depression after world wars, Beckett's plays presented a picture of the world fragmented and disrupted. Among other modern literary works, Beckett's path-breakingly innovative literature presented the parodies of pointlessness of human actions and thoughts in the world. This new dramatic style catapulted Beckett to the centre stage of modern drama, though it should be mentioned that he may not have been influenced in this without the prevailing climate of ideas. The prevailing literary attitude of Modernism indicates that the modern world is irrational and incoherent. The present study explores Samuel Beckett's literary approach to modern drama and shows how the author could create the characters stuck in a lifelong suspicious about the Self.Keywords: modern drama, absurdity, the theatre of the absurd, existentialism, self searching
Procedia PDF Downloads 5291374 Secrecy Analysis in Downlink Cellular Networks in the Presence of D2D Pairs and Hardware Impairment
Authors: Mahdi Rahimi, Mohammad Mahdi Mojahedian, Mohammad Reza Aref
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In this paper, a cellular communication scenario with a transmitter and an authorized user is considered to analyze its secrecy in the face of eavesdroppers and the interferences propagated unintentionally through the communication network. It is also assumed that some D2D pairs and eavesdroppers are randomly located in the cell. Assuming hardware impairment, perfect connection probability is analytically calculated, and upper bound is provided for the secrecy outage probability. In addition, a method based on random activation of D2Ds is proposed to improve network security. Finally, the analytical results are verified by simulations.Keywords: physical layer security, stochastic geometry, device-to-device, hardware impairment
Procedia PDF Downloads 1831373 Constitutive Modeling of Different Types of Concrete under Uniaxial Compression
Authors: Mostafa Jafarian Abyaneh, Khashayar Jafari, Vahab Toufigh
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The cost of experiments on different types of concrete has raised the demand for prediction of their behavior with numerical analysis. In this research, an advanced numerical model has been presented to predict the complete elastic-plastic behavior of polymer concrete (PC), high-strength concrete (HSC), high performance concrete (HPC) along with different steel fiber contents under uniaxial compression. The accuracy of the numerical response was satisfactory as compared to other conventional simple models such as Mohr-Coulomb and Drucker-Prager. In order to predict the complete elastic-plastic behavior of specimens including softening behavior, disturbed state concept (DSC) was implemented by nonlinear finite element analysis (NFEA) and hierarchical single surface (HISS) failure criterion, which is a failure surface without any singularity.Keywords: disturbed state concept (DSC), hierarchical single surface (HISS) failure criterion, high performance concrete (HPC), high-strength concrete (HSC), nonlinear finite element analysis (NFEA), polymer concrete (PC), steel fibers, uniaxial compression test
Procedia PDF Downloads 3111372 Micropropagation of Pelargonium odoratissimum (L.) L’Her., Using Petiole and Leaf Explants
Authors: Mohammad Ali Aazami Mavaloo, Mohammad Bagher Hassanpouraghdam
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Intact leaves, leaf segments and petiole sections derived from nodal explants in vitro were employed for the optimization of Pelargonium odoratissimum micropropagation. MS and ½ MS media enriched with BAP (1, 1.5, 2 and 4.5 mg/l) and NAA (0.1, 1 and 1.5 mg/l) were the treatment combinations used for. With leaf segments, the lowest browning incidence, the greatest callogenesis and the highest number of shoots were obtained with the media containing 1.5 mg/L BAP and 1 mg/L NAA. Two mg/L BAP + 0.1 mg/L NAA hold the same results for petiole explants. Intact leaves showed the best results for the three before-mentioned traits with 1 mg/L BAP + 1 mg/L NAA. 0.2 mg/L NAA caused the highest rooting percentage and the greatest mean data for the number and length of the roots. Rooted plantlets were transferred to the pots containing 1:1 peat-moss and perlite. Acclimatization of the plantlets was followed by 90 percent of survival rate in the greenhouse.Keywords: Pelargonium odoratissimum, micropropagation, BAP, NAA
Procedia PDF Downloads 3971371 Development Framework Based on Mobile Augmented Reality for Pre-Literacy Kit
Authors: Nazatul Aini Abd Majid, Faridah Yunus, Haslina Arshad, Mohammad Farhan Mohammad Johari
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Mobile technology, augmented reality, and game-based learning are some of the key learning technologies that can be fully optimized to promote pre-literacy skills. The problem is how to design an effective pre-literacy kit that utilizes some of the learning technologies. This paper presents a framework based on mobile augmented reality for the development of pre-literacy kit. This pre-literacy kit incorporates three main components which are contents, design, and tools. A prototype of a mobile app based on the three main components was developed for promoting pre-literacy. The results show that the children and teachers gave positive feedbacks after using the mobile app for the pre-literacy.Keywords: framework, mobile technology, augmented reality, pre-literacy skills
Procedia PDF Downloads 5951370 Investigating and Comparing the Performance of Baseboard and Panel Radiators by Calculating the Thermal Comfort Coefficient
Authors: Mohammad Erfan Doraki, Mohammad Salehi
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In this study, to evaluate the performance of Baseboard and Panel radiators with thermal comfort coefficient, A room with specific dimensions was modeled with Ansys fluent and DesignBuilder, then calculated the speed and temperature parameters in different parts of the room in two modes of using Panel and Baseboard radiators and it turned out that use of Baseboard radiators has a more uniform temperature and speed distribution, but in a Panel radiator, the room is warmer. Then, by calculating the thermal comfort indices, It was shown that using a Panel radiator is a more favorable environment and using a Baseboard radiator is a more uniform environment in terms of thermal comfort.Keywords: Radiator, Baseboard, optimal, comfort coefficient, heat
Procedia PDF Downloads 1681369 Peat Soil Stabilization Methods: A Review
Authors: Mohammad Saberian, Mohammad Ali Rahgozar, Reza Porhoseini
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Peat soil is formed naturally through the accumulation of organic matter under water and it consists of more than 75% organic substances. Peat is considered to be in the category of problematic soil, which is not suitable for construction, due to its high compressibility, high moisture content, low shear strength, and low bearing capacity. Since this kind of soil is generally found in many countries and different regions, finding desirable techniques for stabilization of peat is absolutely essential. The purpose of this paper is to review the various techniques applied for stabilizing peat soil and discuss outcomes of its improved mechanical parameters and strength properties. Recognizing characterization of stabilized peat is one of the most significant factors for architectural structures; as a consequence, various strategies for stabilization of this susceptible soil have been examined based on the depth of peat deposit.Keywords: peat soil, stabilization, depth, strength, unconfined compressive strength (USC)
Procedia PDF Downloads 5731368 Modeling and Control of a 4DoF Robotic Assistive Device for Hand Rehabilitation
Authors: Christopher Spiewak, M. R. Islam, Mohammad Arifur Rahaman, Mohammad H. Rahman, Roger Smith, Maarouf Saad
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For those who have lost the ability to move their hand, going through repetitious motions with the assistance of a therapist is the main method of recovery. We have been developed a robotic assistive device to rehabilitate the hand motions in place of the traditional therapy. The developed assistive device (RAD-HR) is comprised of four degrees of freedom enabling basic movements, hand function, and assists in supporting the hand during rehabilitation. We used a nonlinear computed torque control technique to control the RAD-HR. The accuracy of the controller was evaluated in simulations (MATLAB/Simulink environment). To see the robustness of the controller external disturbance as modelling uncertainty (±10% of joint torques) were added in each joints.Keywords: biorobotics, rehabilitation, robotic assistive device, exoskeleton, nonlinear control
Procedia PDF Downloads 4791367 Structure and Optical Properties of Potassium Doped Zinc Oxide
Authors: Lila A. Alkhattaby, Norah A. Alsayegh, Mohammad S. Ansari, Mohammad O. Ansari
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In this work, we doped zinc oxide ZnO with potassium K we have synthesized using the sol-gel method. Structural properties were depicted by X-ray diffractometer (XRD) and energy distribution spectroscopy, X-ray diffraction studies confirm the nanosized of the particles and favored orientations along the (100), (002), (101), (102), (110), (103), (200), and (112) planes confirm the hexagonal wurtzite structure of ZnO NPs. The optical properties study using the UV-Vis spectroscopy. The band gap decreases from 4.05 eV to 3.88 eV, the lowest band gap at 10% doped concentration. The photoluminescence (PL) spectroscopy results show two main peaks, a sharp peak at ≈ 384 nm in the UV region and a broad peak around 479 nm in the visible region. The highest intensity of the band-edge luminescence was for 2% doped concentration because of the combined effect of the decreased probability of nonradiative recombination and has better crystallinity.Keywords: K doped ZnO, photoluminescence spectroscopy, UV-Vis spectroscopy, x-ray spectroscopy
Procedia PDF Downloads 2401366 An investigation of Leading Edge and Trailing Edge Corrugation for Low Reynolds Number Application
Authors: Syed Hassan Raza Shah, Mohammad Mohammad Ali
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The flow over a smoothly profiled airfoil at a low Reynolds number is highly susceptible to separate even at a very low angle of attack. An investigation was made to study the effect of leading-edge and trailing-edge corrugation with the spanwise change in the ridges resulted due to the change in the chord length for an infinite wing. The wind tunnel results using NACA0018 wings revealed that leading and trailing edge corrugation did not have any benefit in terms of aerodynamic efficiency or delayed stall. The leading edge and trailing edge corrugation didn't change the lift curve slope, with the leading edge corrugation wing stalling first in the range of Reynolds number of 50,000 to 125,000.Keywords: leading and trailing edge corrugations, low reynolds number, wind tunnel testing, NACA0018
Procedia PDF Downloads 2911365 Synthesizing and Fabrication of Pani-(SnO₂, ZnO)/rGO by Sol-Gel Method to Develop a Biosensor Thin-Films on Top Glass Substrate
Authors: Mohammad Arifin, Huda Abdullah, Norshafadzila Mohammad Naim
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The fabricated PANI-(SnO₂, ZnO)/rGO nanocomposite thin films for the E. coli bacteria sensor were investigated. The nanocomposite thin films were prepared by the sol-gel method and deposited on the glass substrate using the spin-coating technique. The internal structure and surface morphology of the thin films have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The optical properties of the films were investigated by UV-Vis spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The sensitivity performance was identified by measuring the changing conductivity before and after the incubation of E. coli bacteria using current-voltage (I-V) and cyclic voltammetry (C-V) measurements.Keywords: PANI-(SnO₂, ZnO)/rGO, nanocomposite, bacteria sensor, thin films
Procedia PDF Downloads 1181364 Values That Should Be Taken into Account in the Arts: The Tension between Economic Influences and Cultural Values
Authors: Mohammad Mehdi Mazaheri, Mohammad Motiee Lahromi
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Recently the two matters of how to evaluate art and what the influencing economic effects on cultural values are have attracted many researchers to investigate them. Therefore, in the present article the researcher made an attempt to answer the above questions. However, the fundamental distinction between this article and the other ones is in comparing the economic value (shown by monetary phrases) with cultural values (that reflects the aesthetic values and the importance of the artist). This article shows a different and trivial distinction that has a very clearly pivotal significance in the process of cultural policy making. The economic activities would be influenced when there are cultural values. The increase of commercial activities is measured by impact assessment. In other words, the value of culture is reflected in the satisfaction of the users of cultural activities. This kind of value is measured by “willingness to pay” researches. The researcher believes that these two values are dominant in the cultural policy but they include many aspects and are presented by different kinds of communities.Keywords: economic influence, cultural values, monetary phrases, aesthetic values
Procedia PDF Downloads 4831363 Failure Detection in an Edge Cracked Tapered Pipe Conveying Fluid Using Finite Element Method
Authors: Mohamed Gaith, Zaid Haddadin, Abdulah Wahbe, Mahmoud Hamam, Mahmoud Qunees, Mohammad Al Khatib, Mohammad Bsaileh, Abd Al-Aziz Jaber, Ahmad Aqra’a
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The crack is one of the most common types of failure in pipelines that convey fluid, and early detection of the crack may assist to avoid the piping system from experiencing catastrophic damage, which would otherwise be fatal. The influence of flow velocity and the presence of a crack on the performance of a tapered simply supported pipe containing moving fluid is explored using the finite element approach in this study. ANSYS software is used to simulate the pipe as Bernoulli's beam theory. In this paper, the fluctuation of natural frequencies and matching mode shapes for various scenarios owing to changes in fluid speed and the presence of damage is discussed in detail.Keywords: damage detection, finite element, tapered pipe, vibration characteristics
Procedia PDF Downloads 1701362 In Vitro Micropropagation of Rosa damascena Mill
Authors: Asghar Ebrahimzadeh, Sattar Malekian, Mohammad Ali Aazami, Mohammad Bagher Hassanpouraghdam
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Roses are of main ornamental flowers worldwide. Rosa damascena Mill., besides being an ornamental plant, has major pharmaceutical, cosmetic and fragrance applications. Traditional propagation methods of the plant are using suckers, cutting and grafting. In the present experiment, we used the different explants (leaf section, petioles and nodal cutting) for the optimization of this high-valued ornamental from a native clonal plant. Diverse explants were acquired from mature plants during the growing season and were planted on MS medium supplemented with different hormonal combinations. 70% alcohol and sodium hypochloride were utilized for the surface sterilization. For proliferation, BAP and BA (1-5 mg L-1) and NAA (1-2 mg L-1) were tested. The highest proliferation rate was afforded from MS medium supplemented with 1.5 mg L-1 BA and 5 mg L-1 BAP. Callogenesis from leaf samples and petioles was the best with 1/2 MS medium enriched with 1mg L-1 BAP and 4 mg L-1 2,4-D. Rooting was occurred with the highest frequency in a medium containing 0.1 mg L-1 IBA.Keywords: Rosa damascene, micropropagation, petiole, IBA, BAP
Procedia PDF Downloads 5821361 A Comparative Study of Afghan Traditional and Contemporary Courtyard Housing Regarding Affordable Planning and Sustainability
Authors: Mohammad Saraj Sharifzai, Keisuke Kitagawa, Mohammad Kamil Halimee, Javid Habib, Daishi Sakaguchi
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The purpose of this research is to upgrade a pleasing, sustainable and safe shelter in the Afghan urban community. It also aims to maintain traditional housing, which is fitted to its environment, while attempting to upgrade it with new, traditional standards. The three main objectives of this study are to upgrade the traditional courtyard house to become safe and sustainable today and tomorrow; to fit the contemporary house environmentally and culturally, and to suppress or reduce the broad gap between traditional and contemporary housing. The paper tries to exhibit and analyze the sustainably best practices available in both traditional and contemporary courtyard housing in Afghanistan. For instance, the use of thick walls and Tawa-Khana (floor heating system) shows the best sustainable practice in that context.Keywords: Afghan Traditional Courtyard Housing (ATCH), Afghan Contemporary Courtyard Housing (ACCH), suitability planning, affordable and thermal comfort
Procedia PDF Downloads 4721360 Influence of Flame-Holder on Existence Important Parameters in a Duct Combustion Simulator
Authors: Mohammad Mahdi Doustdar, Mohammad Mojtahedpoor
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The effects of flame-holder position, the ratio of flame holder diameter to combustion chamber diameter and injection angle on fuel propulsive droplets sizing and effective mass fraction have been studied by a cold flow. We named the mass of fuel vapor inside the flammability limit as the effective mass fraction. An empty cylinder as well as a flame-holder which are as a simulator for duct combustion has been considered. The airflow comes into the cylinder from one side and injection operation will be done by four nozzles which are located on the entrance of cylinder. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multi phase, multi component code for the analysis of chemically reacting flows with sprays, is used.Keywords: KIVA-3V, flame-holder, duct combustion, effective mass fraction, mean diameter of droplets
Procedia PDF Downloads 6201359 Investigation on the Effect of Sugarcane Bagasse/HDPE Composition on the Screw Withdrawal Resistance of Injection Molded Parts
Authors: Seyed Abdol Mohammad Rezavand, Mohammad Nikbakhsh
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Withdrawal resistance of screws driven into HDPE/Sugarcane Bagasse injection molded parts was investigated. After chemical treatment and drying, SCB was pre-mixed with HDPE using twin extruder. The resulting granules are used in producing samples in injection molding machine. SCB with the quantity of %10, %20, and %30 was used. By using a suitable fixture, screw heads can take with tensile test machine grips. Parts with screws in the center and edge were fasten together. Then, withdrawal resistance was measured with tensile test machine. Injection gate is at the one edge of the part. The results show that by increasing SCB content in composite, the withdrawal resistance is decreased. Furthermore, the withdrawal resistance at the edges (near injection gate and the end of the filling path of mold cavity) is more than that of the center.Keywords: polyethylene, sugarcane bagasse, wood plastic, screw, withdrawal resistance
Procedia PDF Downloads 5831358 An Approach for Determination of Shotcrete Thickness in Underground Structures
Authors: Mohammad Mohammadi, Mojtaba Askari, Mohammad Farouq Hossaini
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An intrinsic property of rock mass known as rock bolt supporting factor (RSF) or rock bolting capability of rock mass was developed and used for explanation of the mechanism of rock bolting practice. Based on the theory of RSF, numeral values can be assigned to each given rock mass to show the capability of that rock mass to be reinforced by rock bolting. For determination of shotcrete thickness, both safety and cost must be taken into account. The present paper introduces a scientific approach for determination of the necessary shotcrete thickness in underground structures for support purposes using the concept of rock bolt supporting factor (RSF). The proposed approach makes the outcome of shotcrete design one step more accurate than before. The actual dataset of 500 meters of Alborz Tunnel length is used as an example of the application of the approach.Keywords: rock bolt supporting factor (RSF), shotcrete design, underground excavation, Alborz Tunnel
Procedia PDF Downloads 320