Search results for: Ebrahim Farahmand
86 Energy-Efficient Clustering Protocol in Wireless Sensor Networks for Healthcare Monitoring
Authors: Ebrahim Farahmand, Ali Mahani
Abstract:
Wireless sensor networks (WSNs) can facilitate continuous monitoring of patients and increase early detection of emergency conditions and diseases. High density WSNs helps us to accurately monitor a remote environment by intelligently combining the data from the individual nodes. Due to energy capacity limitation of sensors, enhancing the lifetime and the reliability of WSNs are important factors in designing of these networks. The clustering strategies are verified as effective and practical algorithms for reducing energy consumption in WSNs and can tackle WSNs limitations. In this paper, an Energy-efficient weight-based Clustering Protocol (EWCP) is presented. Artificial retina is selected as a case study of WSNs applied in body sensors. Cluster heads’ (CHs) selection is equipped with energy efficient parameters. Moreover, cluster members are selected based on their distance to the selected CHs. Comparing with the other benchmark protocols, the lifetime of EWCP is improved significantly.Keywords: WSN, healthcare monitoring, weighted based clustering, lifetime
Procedia PDF Downloads 30985 Renal Angiomyolipoma Rupture Following COVID-19 Infection: A Case Report
Authors: Mohammed Abdurabu, Akram Al-Warqi, Ebrahim M. A. Ebrahim, Jouhar Kollari, Salman Mirza
Abstract:
The novel coronavirus (COVID-19) is one of the most recent pandemics that invaded earth that left and still leaving hundreds of thousands of patients and ended with high morbidity and mortality rates with no clear cure till this moment. COVID-19 has been proven to be associated with pathologic changes in coagulation, characterized by either thromboembolic or bleeding events. We present this case of a 44-year-old male patient that presented to our Emergency Department with flank pain that later was found to have renal angiomyolipoma (AML) rupture during his COVID-19 infection, ultimately requiring admission for hemorrhage control via Interventional Radiology (IR) drainage. Here, we discuss the role of the front-line physicians and how they should keep a low threshold for the different presentations that could be associated with COVID-19 infection.Keywords: angiomyolipoma, COVID-19, renal, rupture
Procedia PDF Downloads 13184 Development of a New Polymeric Material with Controlled Surface Micro-Morphology Aimed for Biosensors Applications
Authors: Elham Farahmand, Fatimah Ibrahim, Samira Hosseini, Ivan Djordjevic, Leo. H. Koole
Abstract:
Compositions of different molar ratios of polymethylmethacrylate-co-methacrylic acid (PMMA-co-MAA) were synthesized via free- radical polymerization. Polymer coated surfaces have been produced on silicon wafers. Coated samples were analyzed by atomic force microscopy (AFM). The results have shown that the roughness of the surfaces have increased by increasing the molar ratio of monomer methacrylic acid (MAA). This study reveals that the gradual increase in surface roughness is due to the fact that carboxylic functional groups have been generated by MAA segments. Such surfaces can be desirable platforms for fabrication of the biosensors for detection of the viruses and diseases.Keywords: polymethylmethacrylate-co-methacrylic acid (PMMA-co-MAA), polymeric material, atomic force microscopy, roughness, carboxylic functional groups
Procedia PDF Downloads 59583 Supervisory Controller with Three-State Energy Saving Mode for Induction Motor in Fluid Transportation
Authors: O. S. Ebrahim, K. O. Shawky, M. O. S. Ebrahim, P. K. Jain
Abstract:
Induction Motor (IM) driving pump is the main consumer of electricity in a typical fluid transportation system (FTS). It was illustrated that changing the connection of the stator windings from delta to star at no load could achieve noticeable active and reactive energy savings. This paper proposes a supervisory hysteresis liquid-level control with three-state energy saving mode (ESM) for IM in FTS including storage tank. The IM pump drive comprises modified star/delta switch and hydromantic coupler. Three-state ESM is defined, along with the normal running, and named analog to computer ESMs as follows: Sleeping mode in which the motor runs at no load with delta stator connection, hibernate mode in which the motor runs at no load with a star connection, and motor shutdown is the third energy saver mode. A logic flow-chart is synthesized to select the motor state at no-load for best energetic cost reduction, considering the motor thermal capacity used. An artificial neural network (ANN) state estimator, based on the recurrent architecture, is constructed and learned in order to provide fault-tolerant capability for the supervisory controller. Sequential test of Wald is used for sensor fault detection. Theoretical analysis, preliminary experimental testing and, computer simulations are performed to show the effectiveness of the proposed control in terms of reliability, power quality and energy/coenergy cost reduction with the suggestion of power factor correction.Keywords: ANN, ESM, IM, star/delta switch, supervisory control, FT, reliability, power quality
Procedia PDF Downloads 19382 Dental Appointments and Related Fear and Anxiety among the General Population during the COVID-19 Pandemic
Authors: Paria Koraei, Meysam Ahmadzadeh, Reza Shahriarirad, Keivan Ranjbar, Farzane Farahmand
Abstract:
The rapid spread of the coronavirus disease 2019 (COVID-19) has enlisted dental offices in high-risk places. A cross-sectional survey was carried out among the general population aged 17 and above in Shiraz, Fars, Iran. The patients' demographic features were recorded and analyzed against questions regarding fear, anxiety, and attitude toward dental appointments. The Dental Anxiety Scale (DAS) questionnaire was used for the evaluation of anxiety levels. Among a total of 760 participants, the average age was 32.33±11.27 years, while 242 (31.8%) were male and 357 (47%) were single. Based on the anxiety scores, 336 (44.2%) participants had mild anxiety, 215 (28.3%) had moderate anxiety, 74 (9.7%) had high, and 135 (17.8%) had severe anxiety. The majority of participants used masks (93.8%) and disinfectants (79.9%) during dental visits, and the most emphasized policies during dental visits were using disposable face masks by the personnel (83.6%) and controlling the number of visitors in the office (81.8%). Only 226 (29.7%) reported that they hadn’t postponed their dental visits. Our findings demonstrated that anxiety in people increases toward dental treatments during the COVID-19 pandemic, resulting in decreased dental appointments. Dentally anxious people were more likely to be female and married couples. Being female and older age are possible risk factors for developing a fear of dental procedures.Keywords: Covid-19, anxiety, fear, dentistry, dental care
Procedia PDF Downloads 9281 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
Abstract:
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 8280 In-situ Raman Spectroscopy of Flexible Graphene Oxide Films Containing Pt Nanoparticles in The Presense of Atomic Hydrogen
Authors: Ali Moafi, Kourosh Kalantarzadeh, Richard Kaner, Parviz Parvin, Ebrahim Asl Soleimani, Dougal McCulloch
Abstract:
In-situ Raman spectroscopy of flexible graphene-oxide films examined upon exposure to hydrogen gas, air, and synthetic air. The changes in D and G peaks are attributed to defects responding to atomic hydrogen spilled over from the catalytic behavior of Pt nanoparticles distributed all over the film. High-resolution transmission electron microscopy images (HRTEM) as well as electron energy loss spectroscopy (EELS) were carried out to define the density of the samples.Keywords: in situ Raman Spectroscopy, EELS, TEM, graphene oxide, graphene, atomic hydrogen
Procedia PDF Downloads 44979 Cloud-Based Mobile-to-Mobile Computation Offloading
Authors: Ebrahim Alrashed, Yousef Rafique
Abstract:
Mobile devices have drastically changed the way we do things on the move. They are being extremely relied on to perform tasks that are analogous to desktop computer capability. There has been a rapid increase of computational power on these devices; however, battery technology is still the bottleneck of evolution. The primary modern approach day approach to tackle this issue is offloading computation to the cloud, proving to be latency expensive and requiring high network bandwidth. In this paper, we explore efforts to perform barter-based mobile-to-mobile offloading. We present define a protocol and present an architecture to facilitate the development of such a system. We further highlight the deployment and security challenges.Keywords: computational offloading, power conservation, cloud, sandboxing
Procedia PDF Downloads 38878 Postoperative Pain Management: Efficacy of Caudal Tramadol in Pediatric Lower Abdominal Surgery: A Randomized Clinical Study
Authors: Reza Farahmand Rad, Farnad Imani, Azadeh Emami, Reza Salehi, Ali Reza Ghavamy, Ali Nima Shariat
Abstract:
Background: One of the methods of pain control after pediatric surgical procedures is regional techniques, including caudal block, despite their limitations. Objectives: In this study, the pain score and complications of caudal tramadol were evaluated in pediatrics following lower abdom- inal surgery. Methods: In this study, 46 children aged 3 to 10 years were allocated into two equal groups (R and TR) for performing caudal anal- gesia after lower abdominal surgery. The injectate contained 0.2% ropivacaine 1 mL/kg in the R group (control group) and tramadol (2 mg/kg) and ropivacaine in the TR group. The pain score, duration of pain relief, amount of paracetamol consumption, hemody- namic alterations, and possible complications at specific times (1, 2, and 6 hours) were evaluated in both groups. Results: No considerable difference was observed in the pain score between the groups in the first and second hours (P > 0.05). However, in the sixth hour, the TR group had a significantly lower pain score than the R group (P < 0.05). Compared to the R group, the TR group had a longer period of analgesia and lower consumption of analgesic drugs (P < 0.05). Heart rate and blood pressure differences were not significant between the two groups (P > 0.05). Similarly, the duration of operation and recovery time were not remarkably different between the two groups (P > 0.05). Complications had no apparent differences between these two groups, as well (P > 0.05). Conclusions: In this study, the addition of tramadol to caudal ropivacaine in pediatric lower abdominal surgery promoted pain relief without complications.Keywords: tramadol, ropivacaine, caudal block, pediatric, lower abdominal surgery, postoperative pain
Procedia PDF Downloads 1477 Roof Material Detection Based on Object-Based Approach Using WorldView-2 Satellite Imagery
Authors: Ebrahim Taherzadeh, Helmi Z. M. Shafri, Kaveh Shahi
Abstract:
One of the most important tasks in urban area remote sensing is detection of impervious surface (IS), such as building roof and roads. However, detection of IS in heterogeneous areas still remains as one of the most challenging works. In this study, detection of concrete roof using an object-oriented approach was proposed. A new rule-based classification was developed to detect concrete roof tile. The proposed rule-based classification was applied to WorldView-2 image. Results showed that the proposed rule has good potential to predict concrete roof material from WorldView-2 images with 85% accuracy.Keywords: object-based, roof material, concrete tile, WorldView-2
Procedia PDF Downloads 42476 In Silico Study of Antiviral Drugs Against Three Important Proteins of Sars-Cov-2 Using Molecular Docking Method
Authors: Alireza Jalalvand, Maryam Saleh, Somayeh Behjat Khatouni, Zahra Bahri Najafi, Foroozan Fatahinia, Narges Ismailzadeh, Behrokh Farahmand
Abstract:
Object: In the last two decades, the recent outbreak of Coronavirus (SARS-CoV-2) imposed a global pandemic in the world. Despite the increasing prevalence of the disease, there are no effective drugs to treat it. A suitable and rapid way to afford an effective drug and treat the global pandemic is a computational drug study. This study used molecular docking methods to examine the potential inhibition of over 50 antiviral drugs against three fundamental proteins of SARS-CoV-2. METHODS: Through a literature review, three important proteins (a key protease, RNA-dependent RNA polymerase (RdRp), and spike) were selected as drug targets. Three-dimensional (3D) structures of protease, spike, and RdRP proteins were obtained from the Protein Data Bank. Protein had minimal energy. Over 50 antiviral drugs were considered candidates for protein inhibition and their 3D structures were obtained from drug banks. The Autodock 4.2 software was used to define the molecular docking settings and run the algorithm. RESULTS: Five drugs, including indinavir, lopinavir, saquinavir, nelfinavir, and remdesivir, exhibited the highest inhibitory potency against all three proteins based on the binding energies and drug binding positions deduced from docking and hydrogen-bonding analysis. Conclusions: According to the results, among the drugs mentioned, saquinavir and lopinavir showed the highest inhibitory potency against all three proteins compared to other drugs. It may enter laboratory phase studies as a dual-drug treatment to inhibit SARS-CoV-2.Keywords: covid-19, drug repositioning, molecular docking, lopinavir, saquinavir
Procedia PDF Downloads 8875 Reliable and Energy-Aware Data Forwarding under Sink-Hole Attack in Wireless Sensor Networks
Authors: Ebrahim Alrashed
Abstract:
Wireless sensor networks are vulnerable to attacks from adversaries attempting to disrupt their operations. Sink-hole attacks are a type of attack where an adversary node drops data forwarded through it and hence affecting the reliability and accuracy of the network. Since sensor nodes have limited battery power, it is essential that any solution to the sinkhole attack problem be very energy-aware. In this paper, we present a reliable and energy efficient scheme to forward data from source nodes to the base station while under sink-hole attack. The scheme also detects sink-hole attack nodes and avoid paths that includes them.Keywords: energy-aware routing, reliability, sink-hole attack, WSN
Procedia PDF Downloads 39674 A Novel Spectral Index for Automatic Shadow Detection in Urban Mapping Based on WorldView-2 Satellite Imagery
Authors: Kaveh Shahi, Helmi Z. M. Shafri, Ebrahim Taherzadeh
Abstract:
In remote sensing, shadow causes problems in many applications such as change detection and classification. It is caused by objects which are elevated, thus can directly affect the accuracy of information. For these reasons, it is very important to detect shadows particularly in urban high spatial resolution imagery which created a significant problem. This paper focuses on automatic shadow detection based on a new spectral index for multispectral imagery known as Shadow Detection Index (SDI). The new spectral index was tested on different areas of World-View 2 images and the results demonstrated that the new spectral index has a massive potential to extract shadows effectively and automatically.Keywords: spectral index, shadow detection, remote sensing images, World-View 2
Procedia PDF Downloads 53873 FEM Investigation of Inhomogeneous Wall Thickness Backward Extrusion for Aerosol Can Manufacturing
Authors: Jemal Ebrahim Dessie, Zsolt Lukacs
Abstract:
The wall of the aerosol can is extruded from the backward extrusion process. Necking is another forming process stage developed on the can shoulder after the backward extrusion process. Due to the thinner thickness of the wall, buckling is the critical challenge for current pure aluminum aerosol can industries. Design and investigation of extrusion with inhomogeneous wall thickness could be the best solution for reducing and optimization of neck retraction numbers. FEM simulation of inhomogeneous wall thickness has been simulated through this investigation. From axisymmetric Deform-2D backward extrusion, an aerosol can with a thickness of 0.4 mm at the top and 0.33 mm at the bottom of the aerosol can have been developed. As the result, it can optimize the number of retractions of the necking process and manufacture defect-free aerosol can shoulder due to the necking process.Keywords: aerosol can, backward extrusion, Deform-2D, necking
Procedia PDF Downloads 18872 Design and Performance Evaluation of Synchronous Reluctance Machine (SynRM)
Authors: Hadi Aghazadeh, Mohammadreza Naeimi, Seyed Ebrahim Afjei, Alireza Siadatan
Abstract:
Torque ripple, maximum torque and high efficiency are important issues in synchronous reluctance machine (SynRM). This paper presents a view on design of a high efficiency, low torque ripple and high torque density SynRM. To achieve this goal SynRM parameters is calculated (such as insulation ratios in the d-and q-axes and the rotor slot pitch), while the torque ripple can be minimized by determining the best rotor slot pitch in the d-axis. The presented analytical-finite element method (FEM) approach gives the optimum distribution of air gap and iron portion for the maximizing torque density with minimum torque ripple.Keywords: torque ripple, efficiency, insulation ratio, FEM, synchronous reluctance machine (SynRM), induction motor (IM)
Procedia PDF Downloads 22771 CMOS Solid-State Nanopore DNA System-Level Sequencing Techniques Enhancement
Authors: Syed Islam, Yiyun Huang, Sebastian Magierowski, Ebrahim Ghafar-Zadeh
Abstract:
This paper presents system level CMOS solid-state nanopore techniques enhancement for speedup next generation molecular recording and high throughput channels. This discussion also considers optimum number of base-pair (bp) measurements through channel as an important role to enhance potential read accuracy. Effective power consumption estimation offered suitable rangeof multi-channel configuration. Nanopore bp extraction model in statistical method could contribute higher read accuracy with longer read-length (200 < read-length). Nanopore ionic current switching with Time Multiplexing (TM) based multichannel readout system contributed hardware savings.Keywords: DNA, nanopore, amplifier, ADC, multichannel
Procedia PDF Downloads 45370 A Nonstandard Finite Difference Method for Weather Derivatives Pricing Model
Authors: Clarinda Vitorino Nhangumbe, Fredericks Ebrahim, Betuel Canhanga
Abstract:
The price of an option weather derivatives can be approximated as a solution of the two-dimensional convection-diffusion dominant partial differential equation derived from the Ornstein-Uhlenbeck process, where one variable represents the weather dynamics and the other variable represent the underlying weather index. With appropriate financial boundary conditions, the solution of the pricing equation is approximated using a nonstandard finite difference method. It is shown that the proposed numerical scheme preserves positivity as well as stability and consistency. In order to illustrate the accuracy of the method, the numerical results are compared with other methods. The model is tested for real weather data.Keywords: nonstandard finite differences, Ornstein-Uhlenbeck process, partial differential equations approach, weather derivatives
Procedia PDF Downloads 10969 The Effect of Acute Toxicity and Thyroid Hormone Treatments on Hormonal Changes during Embryogenesis of Acipenser persicus
Authors: Samaneh Nazeri, Bagher Mojazi Amiri, Hamid Farahmand
Abstract:
Production of high quality fish eggs with reasonable hatching rate makes a success in aquaculture industries. It is influenced by the environmental stimulators and inhibitors. Diazinon is a widely-used pesticide in Golestan province (Southern Caspian Sea, North of Iran) which is washed to the aquatic environment (3 mg/L in the river). It is little known about the effect of this pesticide on the embryogenesis of sturgeon fish, the valuable species of the Caspian Sea. Hormonal content of the egg is an important factor to guaranty the successful passes of embryonic stages. In this study, the fate of Persian sturgeon embryo to 24, 48, 72, and 96-hours exposure of diazinon (LC50 dose) was tested. Also, the effect of thyroid hormones (T3 and T4) on these embryos was tested concurrently or separately with diazinon LC 50 dose. Fertilized eggs are exposed to T3 (low dose: 1 ng/ml, high dose: 10 ng/ml), T4 (low dose: 1 ng/ml, high dose: 10 ng/ml). Six eggs were randomly selected from each treatment (with three replicates) in five developmental stages (two cell- division, neural, heart present, heart beaten, and hatched larvae). The possibility of changing T3, T4, and cortisol contents of the embryos were determined in all treated groups and in every mentioned embryonic stage. The hatching rate in treated groups was assayed at the end of the embryogenesis to clarify the effect of thyroid hormones and diazinon. The results indicated significant differences in thyroid hormone contents, but no significant differences were recognized in cortisol levels at various early life stages of embryos. There was also significant difference in thyroid hormones in (T3, T4) + diazinon treated embryos (P˂0.05), while no significant difference between control and treatments in cortisol levels was observed. The highest hatching rate was recorded in HT3 treatment, while the lowest hatching rate was recorded for diazinon LC50 treatment. The result confirmed that Persian sturgeon embryo is less sensitive to diazinon compared to teleost embryos, and thyroid hormones may increase hatching rate even in the presence of diazinon.Keywords: Persian sturgeon, diazinon, thyroid hormones, cortisol, embryo
Procedia PDF Downloads 30368 Integrating Deterministic and Probabilistic Safety Assessment to Decrease Risk & Energy Consumption in a Typical PWR
Authors: Ebrahim Ghanbari, Mohammad Reza Nematollahi
Abstract:
Integrating deterministic and probabilistic safety assessment (IDPSA) is one of the most commonly used issues in the field of safety analysis of power plant accident. It has also been recognized today that the role of human error in creating these accidents is not less than systemic errors, so the human interference and system errors in fault and event sequences are necessary. The integration of these analytical topics will be reflected in the frequency of core damage and also the study of the use of water resources in an accident such as the loss of all electrical power of the plant. In this regard, the SBO accident was simulated for the pressurized water reactor in the deterministic analysis issue, and by analyzing the operator's behavior in controlling the accident, the results of the combination of deterministic and probabilistic assessment were identified. The results showed that the best performance of the plant operator would reduce the risk of an accident by 10%, as well as a decrease of 6.82 liters/second of the water sources of the plant.Keywords: IDPSA, human error, SBO, risk
Procedia PDF Downloads 12967 An Intrusion Detection Systems Based on K-Means, K-Medoids and Support Vector Clustering Using Ensemble
Authors: A. Mohammadpour, Ebrahim Najafi Kajabad, Ghazale Ipakchi
Abstract:
Presently, computer networks’ security rise in importance and many studies have also been conducted in this field. By the penetration of the internet networks in different fields, many things need to be done to provide a secure industrial and non-industrial network. Fire walls, appropriate Intrusion Detection Systems (IDS), encryption protocols for information sending and receiving, and use of authentication certificated are among things, which should be considered for system security. The aim of the present study is to use the outcome of several algorithms, which cause decline in IDS errors, in the way that improves system security and prevents additional overload to the system. Finally, regarding the obtained result we can also detect the amount and percentage of more sub attacks. By running the proposed system, which is based on the use of multi-algorithmic outcome and comparing that by the proposed single algorithmic methods, we observed a 78.64% result in attack detection that is improved by 3.14% than the proposed algorithms.Keywords: intrusion detection systems, clustering, k-means, k-medoids, SV clustering, ensemble
Procedia PDF Downloads 22166 Preparation and Characterization of Hybrid Perovskite Enhanced with PVDF for Pressure Sensing
Authors: Mohamed E. Harb, Enas Moustafa, Shaker Ebrahim, Moataz Soliman
Abstract:
In this paper pressure detectors were synthesized and characterized using hybrid perovskite/PVDF composites as an active layer. Methylammonium lead iodide (MAPbI₃) was synthesized from methylammonium iodide (MAI) (CH₃NH₃I) and lead iodide (PbI₂). Composites of perovskite/PVDF using different weight ratio were prepared as the active material. PVDF with weights percentages of 6%, 8%, and 10% was used. All prepared materials were investigated by x-ray diffraction (XRD), Fourier transforms infrared spectrum (FTIR) and scanning electron microscopy (SEM). A Versastat 4 Potentiostat Galvanostat instrument was used to perform the current-voltage characteristics of the fabricated sensors. The pressure sensors exhibited a voltage increase with applying different forces. Also, the current-voltage characteristics (CV) showed different effects with applying forces. So, the results showed a good pressure sensing performance.Keywords: perovskite semiconductor, hybrid perovskite, PVDF, Pressure sensing
Procedia PDF Downloads 20765 Thixomixing as Novel Method for Fabrication Aluminum Composite with Carbon and Alumina Fibers
Authors: Ebrahim Akbarzadeh, Josep A. Picas Barrachina, Maite Baile Puig
Abstract:
This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.Keywords: aluminum, carbon fiber, alumina fiber, thixomixing, adhesion
Procedia PDF Downloads 55764 Does Level of Countries Corruption Affect Firms Working Capital Management?
Authors: Ebrahim Mansoori, Datin Joriah Muhammad
Abstract:
Recent studies in finance have focused on the effect of external variables on working capital management. This study investigates the effect of corruption indexes on firms' working capital management. A large data set that covers data from 2005 to 2013 from five ASEAN countries, namely, Malaysia, Indonesia, Singapore, Thailand, and the Philippines, was selected to investigate how the level of corruption in these countries affect working capital management. The results of panel data analysis include fixed effect estimations showed that a high level of countries' corruption indexes encourages managers to shorten the CCC length. Meanwhile, the managers reduce the level of investment in cash and cash equivalents when the levels of corruption indexes increase. Therefore, increasing the level of countries' corruption indexes encourages managers to select conservative working capital strategies by reducing the level of NLB.Keywords: ASEAN, corruption indexes, panel data analysis, working capital management
Procedia PDF Downloads 43863 In vitro Study of Laser Diode Radiation Effect on the Photo-Damage of MCF-7 and MCF-10A Cell Clusters
Authors: A. Dashti, M. Eskandari, L. Farahmand, P. Parvin, A. Jafargholi
Abstract:
Breast Cancer is one of the most considerable diseases in the United States and other countries and is the second leading cause of death in women. Common breast cancer treatments would lead to adverse side effects such as loss of hair, nausea, and weakness. These complications arise because these cancer treatments damage some healthy cells while eliminating the cancer cells. In an effort to address these complications, laser radiation was utilized and tested as a targeted cancer treatment for breast cancer. In this regard, tissue engineering approaches are being employed by using an electrospun scaffold in order to facilitate the growth of breast cancer cells. Polycaprolacton (PCL) was used as a material for scaffold fabricating because of its biocompatibility, biodegradability, and supporting cell growth. The specific breast cancer cells have the ability to create a three-dimensional cell cluster due to the spontaneous accumulation of cells in the porosity of the scaffold under some specific conditions. Therefore, we are looking for a higher density of porosity and larger pore size. Fibers showed uniform diameter distribution and final scaffold had optimum characteristics with approximately 40% porosity. The images were taken by SEM and the density and the size of the porosity were determined with the Image. After scaffold preparation, it has cross-linked by glutaraldehyde. Then, it has been washed with glycine and phosphate buffer saline (PBS), in order to neutralize the residual glutaraldehyde. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) results have represented approximately 91.13% viability of the scaffolds for cancer cells. In order to create a cluster, Michigan Cancer Foundation-7 (MCF-7, breast cancer cell line) and Michigan Cancer Foundation-10A (MCF-10A, human mammary epithelial cell line) cells were cultured on the scaffold in 24 well plate for five days. Then, we have exposed the cluster to the laser diode 808 nm radiation to investigate the effect of laser on the tumor with different power and time. Under the same conditions, cancer cells lost their viability more than the healthy ones. In conclusion, laser therapy is a viable method to destroy the target cells and has a minimum effect on the healthy tissues and cells and it can improve the other method of cancer treatments limitations.Keywords: breast cancer, electrospun scaffold, polycaprolacton, laser diode, cancer treatment
Procedia PDF Downloads 14362 Effect of Nitrogen Management on Nitrogen Uptake, Dry Matter Production and Some Yield Parameters
Authors: Mandana Tayefe, Ebrahim Amiri, Azin Nasrollah Zade
Abstract:
Effect of nitrogen (N) fertilizer levels on nitrogen uptake, dry matter production, yield and some yield components of rice (Hashemi, Kazemi, Khazar) was investigated in an experiment as factorial in RCBD with 3 replications in a paddy light soil at Guilan province, Iran, 2008-2009. In this experiment, four treatments including: N1-control (no N fertilizer); N2- 30 kgN/ha; N3- 60 kgN/ha; N4- 90 kgN/ha were compared. Results showed that total biomass (8386 kg/ha), grain yield (3662 kg/ha), panicles m-2 (235.8) and total grain per panicle (103.8) were reached the highest value at high nitrogen level. Among the varieties the highest total biomass (7734 kg/ha), grain yield (3414 kg/ha) and total grain per panicle (78.2) belonged to Khazar. Dry matter, total N uptake was varied in different cultivars significantly and Khazar variety had the highest contents. Total biomass and total N uptake was varied significantly with the increasement of the amount of nitrogen applied. As total biomass and total N uptake increased with increasing in N fertilizing.Keywords: rice, nitrogen, nitrogen uptake, dry matter
Procedia PDF Downloads 41561 Performance Investigation of UAV Attitude Control Based on Modified PI-D and Nonlinear Dynamic Inversion
Authors: Ebrahim Hassan Kapeel, Ahmed Mohsen Kamel, Hossan Hendy, Yehia Z. Elhalwagy
Abstract:
Interest in autopilot design has been raised intensely as a result of recent advancements in Unmanned Aerial vehicles (UAVs). Due to the enormous number of applications that UAVs can achieve, the number of applied control theories used for them has increased in recent years. These small fixed-wing UAVs are suffering high non-linearity, sensitivity to disturbances, and coupling effects between their channels. In this work, the nonlinear dynamic inversion (NDI) control lawisdesigned for a nonlinear small fixed-wing UAV model. The NDI is preferable for varied operating conditions, there is no need for a scheduling controller. Moreover, it’s applicable for high angles of attack. For the designed flight controller validation, a nonlinear Modified PI-D controller is performed with our model. A comparative study between both controllers is achieved to evaluate the NDI performance. Simulation results and analysis are proposed to illustrate the effectiveness of the designed controller based on NDI.Keywords: UAV dynamic model, attitude control, nonlinear PID, dynamic inversion
Procedia PDF Downloads 11060 Optimization of Floor Heating System in the Incompressible Turbulent Flow Using Constructal Theory
Authors: Karim Farahmandfar, Hamidolah Izadi, Mohammadreza Rezaei, Amin Ardali, Ebrahim Goshtasbi Rad, Khosro Jafarpoor
Abstract:
Statistics illustrates that the higher amount of annual energy consumption is related to surmounting the demand in buildings. Therefore, it is vital to economize the energy consumption and also find the solution with regard to this issue. One of the systems for the sake of heating the building is floor heating. As a matter of fact, floor heating performance is based on convection and radiation. Actually, in addition to creating a favorable heating condition, this method leads to energy saving. It is the goal of this article to outline the constructal theory and introduce the optimization method in branch networks for floor heating. There are several steps in order to gain this purpose. First of all, the pressure drop through the two points of the network is calculated. This pressure drop is as a function of pipes diameter and other parameters. After that, the amount of heat transfer is determined. Consequently, as a result of the combination of these two functions, the final function will be determined. It is necessary to mention that flow is laminar.Keywords: constructal theory, optimization, floor heating system, turbulent flow
Procedia PDF Downloads 31959 Adsorption of Cerium as One of the Rare Earth Elements Using Multiwall Carbon Nanotubes from Aqueous Solution: Modeling, Equilibrium and Kinetics
Authors: Saeb Ahmadi, Mohsen Vafaie Sefti, Mohammad Mahdi Shadman, Ebrahim Tangestani
Abstract:
Carbon nanotube has shown great potential for the removal of various inorganic and organic components due to properties such as large surface area and high adsorption capacity. Central composite design is widely used method for determining optimal conditions. Also due to the economic reasons and wide application, the rare earth elements are important components. The analyses of cerium (Ce(III)) adsorption as one of the Rare Earth Elements (REEs) adsorption on Multiwall Carbon Nanotubes (MWCNTs) have been studied. The optimization process was performed using Response Surface Methodology (RSM). The optimum amount conditions were pH of 4.5, initial Ce (III) concentration of 90 mg/l and MWCNTs dosage of 80 mg. Under this condition, the optimum adsorption percentage of Ce (III) was obtained about 96%. Next, at the obtained optimum conditions the kinetic and isotherm studied and result showed the pseudo-second order and Langmuir isotherm are more fitted with experimental data than other models.Keywords: cerium, rare earth element, MWCNTs, adsorption, optimization
Procedia PDF Downloads 16758 Performance Investigation of Unmanned Aerial Vehicles Attitude Control Based on Modified PI-D and Nonlinear Dynamic Inversion
Authors: Ebrahim H. Kapeel, Ahmed M. Kamel, Hossam Hendy, Yehia Z. Elhalwagy
Abstract:
Interest in autopilot design has been raised intensely as a result of recent advancements in Unmanned Aerial vehicles (UAVs). Due to the enormous number of applications that UAVs can achieve, the number of applied control theories used for them has increased in recent years. These small fixed-wing UAVs are suffering high non-linearity, sensitivity to disturbances, and coupling effects between their channels. In this work, the nonlinear dynamic inversion (NDI) control law is designed for a nonlinear small fixed-wing UAV model. The NDI is preferable for varied operating conditions, there is no need for a scheduling controller. Moreover, it’s applicable for high angles of attack. For the designed flight controller validation, a nonlinear Modified PI-D controller is performed with our model. A comparative study between both controllers is achieved to evaluate the NDI performance. Simulation results and analysis are proposed to illustrate the effectiveness of the designed controller based on NDI.Keywords: attitude control, nonlinear PID, dynamic inversion
Procedia PDF Downloads 11057 Design of Collection and Transportation System of Municipal Solid Waste in Meshkinshahr City
Authors: Ebrahim Fataei, Seyed Ali Hosseini, Zahra Arabi, Habib farhadi, Mehdi Aalipour Erdi, Seiied Taghi Seiied Safavian
Abstract:
Solid waste production is an integral part of human life and management of waste require full scientific approach and essential planning. The allocation of most management cost to collection and transportation and also the necessity of operational efficiency in this system, by limiting time consumption, and on the other hand optimum collection system and transportation is the base of waste design and management. This study was done to optimize the exits collection and transportation system of solid waste in Meshkinshahr city. So based on the analyzed data of municipal solid waste components in seven zones of Meshkinshahr city, and GIS software, applied to design storage place based on origin recycling and a route to collect and transport. It was attempted to represent an appropriate model to store, collect and transport municipal solid waste. The result shows that GIS can be applied to locate the waste container and determine a waste collection direction in an appropriate way.Keywords: municipal solid waste management, transportation, optimizing, GIS, Iran
Procedia PDF Downloads 534