Search results for: Ali Reza Tahavvor‚ Saeed Hosseini
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 872

Search results for: Ali Reza Tahavvor‚ Saeed Hosseini

782 A Single Switch High Step-Up DC/DC Converter with Zero Current Switching Condition

Authors: Rahil Samani, Saeed Soleimani, Ehsan Adib, Majid Pahlevani

Abstract:

This paper presents an inverting high step-up DC/DC converter. Basically, this high step-up DC/DC converter is an appealing interface for solar applications. The proposed topology takes advantage of using coupled inductors. Due to the leakage inductances of these coupled inductors, the power MOSFET has the zero current switching (ZCS) condition, which results in decreased switching losses. This will substantially improve the overall efficiency of the power converter. Furthermore, employing coupled inductors has led to a higher voltage gain. Theoretical analysis and experimental results of a 100W 20V/220V prototype are presented to verify the superior performance of the proposed DC/DC converter.

Keywords: coupled inductors, high step-up DC/DC converter, zero-current switching, Cuk converter, SEPIC converter

Procedia PDF Downloads 683
781 Effects of Carbon Dioxide on the Organoleptic Properties of Hazelnut

Authors: Reza Sadeghi

Abstract:

Carbon dioxide treatment is one of the new methods for storage pest control. It can be used to replace chemical approaches for postharvest. Hazelnut has a considerable share in the annual exports of Iran. In the present study, hazelnut was studied after being exposed to different CO2 pressures (0.1-0.5bar) within 24 hours. Changes in organoleptic properties (colour, firmness, aroma, crispness, and overall acceptability) during fumigation were studied. The results showed that the sensory evaluation showed that carbon dioxide had no effect on the qualitative characteristics of hazelnut.

Keywords: carbon dioxide, hazelnut, qualitative characteristics, organoleptic

Procedia PDF Downloads 52
780 Chaotic Behavior in Monetary Systems: Comparison among Different Types of Taylor Rule

Authors: Reza Moosavi Mohseni, Wenjun Zhang, Jiling Cao

Abstract:

The aim of the present study is to detect the chaotic behavior in monetary economic relevant dynamical system. The study employs three different forms of Taylor rules: current, forward, and backward looking. The result suggests the existence of the chaotic behavior in all three systems. In addition, the results strongly represent that using expectations especially rational expectation hypothesis can increase complexity of the system and leads to more chaotic behavior.

Keywords: taylor rule, monetary system, chaos theory, lyapunov exponent, GMM estimator

Procedia PDF Downloads 490
779 Relationship between Quality Education and Organizational Culture at College Level in Punjab

Authors: Anam Noshaba, Mahr Muhammad Saeed Akhtar

Abstract:

The aim of this study was to find out the relationship between quality education and organizational culture. The population of this study was all the teachers of Public Degree Colleges located in Punjab. A sample of 400 teachers was selected by using a simple random sampling technique. Quality Education Assessment Questionnaire (QEAQ) and Organizational Culture Assessment Instrument (OCAI) were used for data collection. Out of all, 90% of teachers responded. Findings showed that quality education and organizational culture are positively correlated. Results indicated that there is no difference in quality education and organizational culture by demographic variables of teachers. Future research is needed to study the viewpoint of other stakeholders of education regarding quality education and organizational culture.

Keywords: quality education, minimum quality standards, organizational culture, college level

Procedia PDF Downloads 101
778 Benefits of Therapeutic Climbing on Multiple Components of Attention in Attention Deficit Hyperactivity Disorder Children

Authors: Elaheh Hosseini, Otmar Bock, Monika Thomas

Abstract:

The purpose of the present study was to determine the effect of climbing therapy on the components of attention of children with attention-deficit hyperactivity disorder (ADHD). Forty children with ADHD were assigned to either an intervention group or a control group. The exercise group participated in a climbing therapy program for ten weeks, whereas no intervention was administered to the control group. All two groups were then assessed with the same battery of attention tests used in our earlier study. We found that compared to the ‘intervention’ group, performance was higher in the ‘control’ group on tests of sustained, divided and distributed attention, on all four tests. The intervention group showed a significant improvement in components of attention after ten weeks. From this we conclude that climbing therapy can improve the attention of children with ADHD and can be considered as a promising intervention and a standalone treatment for children with ADHD.

Keywords: ADHD, climbing therapy, distributed attention, divided attention, selective attention, sustained attention

Procedia PDF Downloads 134
777 Green and Facile Fabrication and Characterization of Fe/ZnO Hollow Spheres and Photodegradation of Azo Dyes

Authors: Seyed Mohsen Mousavi, Ali Reza Mahjoub, Bahjat Afshari Razani

Abstract:

In this work, Fe/ZnO hollow spherical structures with high surface area using the template glucose was prepared by the hydrothermal method using an ultrasonic bath at room temperature was produced and were identified by FT-IR, XRD, FE-SEM and BET. The photocatalytic activity of synthesized spherical Fe/ZnO hollow sphere were studied in the destruction of Congo Red and Methylene Blue as Azo dyes. The results showed that the photocatalytic activity of Fe/ZnO hollow spherical structures is improved compared with ZnO hollow sphere and other morphologys.

Keywords: azo dyes, Fe/ZnO hollow sphere, hollow sphere nanostructures, photocatalyst

Procedia PDF Downloads 327
776 The Lubrication Regimes Recognition of a Pressure-Fed Journal Bearing by Time and Frequency Domain Analysis of Acoustic Emission Signals

Authors: S. Hosseini, M. Ahmadi Najafabadi, M. Akhlaghi

Abstract:

The health of the journal bearings is very important in preventing unforeseen breakdowns in rotary machines, and poor lubrication is one of the most important factors for producing the bearing failures. Hydrodynamic lubrication (HL), mixed lubrication (ML), and boundary lubrication (BL) are three regimes of a journal bearing lubrication. This paper uses acoustic emission (AE) measurement technique to correlate features of the AE signals to the three lubrication regimes. The transitions from HL to ML based on operating factors such as rotating speed, load, inlet oil pressure by time domain and time-frequency domain signal analysis techniques are detected, and then metal-to-metal contacts between sliding surfaces of the journal and bearing are identified. It is found that there is a significant difference between theoretical and experimental operating values that are obtained for defining the lubrication regions.

Keywords: acoustic emission technique, pressure fed journal bearing, time and frequency signal analysis, metal-to-metal contact

Procedia PDF Downloads 126
775 Subtidal Crabs of Oman Sea: New Collections and Biogeographic Considerations

Authors: Negar Ghotbeddin, Seied Mohammad Reza Fatemi, Tooraj Valinassab

Abstract:

The samplings were carried out at 8 stations (Govatr, Pasabandar, Beriss, Ramin, Chabahar, Pozm, Gordim, and Meidani) in subtidal zones of Oman Sea during the year 2009-2010. The specimens were collected by trawl net and preserved in 70% alcohol. A total of 23 species belonged to 9 families and 15 genera were caught. The results of the present study revealed that families Portunidae had the highest species enriched with 9 species. Most of the species had high distribution in the west Indian Ocean (69.56%) and 8.69% of species were endemic. Almost species were similar to those found in the Persian Gulf.

Keywords: Brachyura, biogeography, subtidal, Oman Sea

Procedia PDF Downloads 557
774 Carbon Credits in Voluntary Carbon Markets: A Proposal for Iran

Authors: Saeed Mohammadirad

Abstract:

During the first commitment period of the Kyoto Protocol, many developed countries were forced to restrict carbon emissions. Although Iran was one of the countries of Kyoto protocol, due to some special conditions, it was not required to restrict its carbon emissions. Flexible mechanisms were developed to assist countries responsible for reducing their carbon emissions, and regulated carbon markets were introduced. Carbon credits which are provided by organizations in countries with no responsibility to restrict their carbon emissions are traded in voluntary markets. This study focuses on how to measure and report the carbon allowances and carbon credits from accounting view point under both regulated and voluntary markets.

Keywords: carbon credits, carbon markets, accounting, flexible mechanisms

Procedia PDF Downloads 369
773 Static Properties of Ge and Sr Isotopes in the Cluster Model

Authors: Mohammad Reza Shojaei, Mahdeih Mirzaeinia

Abstract:

We have studied the cluster structure of even-even stable isotopes of Ge and Sr. The Schrodinger equation has been solved using the generalized parametric Nikiforov-Uvarov method with a phenomenological potential. This potential is the sum of the attractive Yukawa-like potential, a Manning-Rosen-type potential, and the repulsive Yukawa potential for interaction between the cluster and the core. We have shown that the available experimental data of the first rotational band energies can be well described by assuming a binary system of the α cluster and the core and using an analytical solution. Our results were consistent with experimental values. Hence, this model can be applied to study the other even-even isotopes

Keywords: cluser model, NU method, ge and Sr, potential central

Procedia PDF Downloads 40
772 Optimization of Processing Parameters of Acrylonitrile–Butadiene–Styrene Sheets Integrated by Taguchi Method

Authors: Fatemeh Sadat Miri, Morteza Ehsani, Seyed Farshid Hosseini

Abstract:

The present research is concerned with the optimization of extrusion parameters of ABS sheets by the Taguchi experimental design method. In this design method, three parameters of % recycling ABS, processing temperature and degassing time on mechanical properties, hardness, HDT, and color matching of ABS sheets were investigated. The variations of this research are the dosage of recycling ABS, processing temperature, and degassing time. According to experimental test data, the highest level of tensile strength and HDT belongs to the sample with 5% recycling ABS, processing temperature of 230°C, and degassing time of 3 hours. Additionally, the minimum level of MFI and color matching belongs to this sample, too. The present results are in good agreement with the Taguchi method. Based on the outcomes of the Taguchi design method, degassing time has the most effect on the mechanical properties of ABS sheets.

Keywords: ABS, process optimization, Taguchi, mechanical properties

Procedia PDF Downloads 41
771 Evaluation of Dynamic Behavior of a Rotor-Bearing System in Operating Conditions

Authors: Mohammad Hadi Jalali, Behrooz Shahriari, Mostafa Ghayour, Saeed Ziaei-Rad, Shahram Yousefi

Abstract:

Most flexible rotors can be considered as beam-like structures. In many cases, rotors are modeled as one-dimensional bodies, made basically of beam-like shafts with rigid bodies attached to them. This approach is typical of rotor dynamics, both analytical and numerical, and several rotor dynamic codes, based on the finite element method, follow this trend. In this paper, a finite element model based on Timoshenko beam elements is utilized to analyze the lateral dynamic behavior of a certain rotor-bearing system in operating conditions.

Keywords: finite element method, Timoshenko beam elements, operational deflection shape, unbalance response

Procedia PDF Downloads 389
770 Corporate Law and Its View Point of Locking in Capital

Authors: Saad Saeed Althiabi

Abstract:

This paper discusses the corporate positioning and how it became popular as a way to systematize production because of the unique manner in which incorporation legalized organizers to secure financial capital through locking it in. The power to lock in capital comes from the fact that a corporate exists as a separate legal entity, whose survival and governance are separated from any of its participants. The law essentially creates a different legal person when a corporation is created. Although this idea has been played down in the legal learning of the last decades in favor of the view that a corporation is purely something through which natural persons interrelate, recent legal research has begun to reassess the importance of entity status. Entity status, under the law and the related separation of governance from input of financial capital through the configuration of a corporation, sanctioned corporate participants to do somewhat more than connect in a series of business transactions.

Keywords: corporate law, entity status, locking in capital, financial capital

Procedia PDF Downloads 523
769 Approximation Algorithms for Peak-Demand Reduction

Authors: Zaid Jamal Saeed Almahmoud

Abstract:

Smart grid is emerging as the future power grid, with smart techniques to optimize power consumption and electricity generation. Minimizing peak power consumption under a fixed delay requirement is a significant problem in the smart grid.For this problem, all appliances must be scheduled within a given finite time duration. We consider the problem of minimizing the peak demand under appliances constraints by scheduling power jobs with uniform release dates and deadlines. As the problem is known to be NP-hard, we analyze the performance of a version of the natural greedy heuristic for solving this problem. Our theoretical analysis and experimental results show that the proposed heuristic outperforms existing methods by providing a better approximation to the optimal solution.

Keywords: peak demand scheduling, approximation algorithms, smart grid, heuristics

Procedia PDF Downloads 65
768 Finite Element Analysis of Debonding Propagation in FM73 Joint under Static Loading

Authors: Reza Hedayati, Meysam Jahanbakhshi

Abstract:

In this work, Fracture Mechanics is used to predict crack propagation in the adhesive joining aluminum and composite plates. Three types of loadings and two types of glass-epoxy composite sequences: [0/90]2s and [0/45/-45/90]s are considered for the composite plate. Therefore, 2*3=6 cases are considered and their results are compared. The debonding initiation load, complete debonding load, crack face profile and load-displacement diagram have been compared for the six cases.

Keywords: adhesive joint, debonding, fracture, LEFM, APDL

Procedia PDF Downloads 562
767 Imami Shia and Democracy

Authors: Hamid Reza Shariatmadari

Abstract:

The Muslims who believe in twelve Imams and believe that their twelfth Imam is now hidden, because of their kind of consideration of immune Imam as their unique canonical authority for interpretation of Islam, are subject of these important questions; how can you be democratic? And can you speak of democracy as the best model of governing? Answering this question, we can talk firstly about the nature of democracy and realize it as a way and mechanism not as a philosophy of identity and secondly we can refer to the nature and functions of Imam in Shiism and thirdly we will focus on the age of Ghaybah (Or concealment of Imam). In such a time we can or have to combine domination of Islamic Faqis (Islamic Jurists) and democracy which is known in Shiite Iran for instance as religious democracy.

Keywords: Shiism, concealment of Imam, Islamic Jurists, Democracy

Procedia PDF Downloads 456
766 Algorithm Optimization to Sort in Parallel by Decreasing the Number of the Processors in SIMD (Single Instruction Multiple Data) Systems

Authors: Ali Hosseini

Abstract:

Paralleling is a mechanism to decrease the time necessary to execute the programs. Sorting is one of the important operations to be used in different systems in a way that the proper function of many algorithms and operations depend on sorted data. CRCW_SORT algorithm executes ‘N’ elements sorting in O(1) time on SIMD (Single Instruction Multiple Data) computers with n^2/2-n/2 number of processors. In this article having presented a mechanism by dividing the input string by the hinge element into two less strings the number of the processors to be used in sorting ‘N’ elements in O(1) time has decreased to n^2/8-n/4 in the best state; by this mechanism the best state is when the hinge element is the middle one and the worst state is when it is minimum. The findings from assessing the proposed algorithm by other methods on data collection and number of the processors indicate that the proposed algorithm uses less processors to sort during execution than other methods.

Keywords: CRCW, SIMD (Single Instruction Multiple Data) computers, parallel computers, number of the processors

Procedia PDF Downloads 284
765 Prediction of Crack Propagation in Bonded Joints Using Fracture Mechanics

Authors: Reza Hedayati, Meysam Jahanbakhshi

Abstract:

In this work, Fracture Mechanics is used to predict crack propagation in the adhesive jointing aluminum and composite plates. Three types of loadings and two types of glass-epoxy composite sequences: [0/90]2s and [0/45/-45/90]s are considered for the composite plate. Therefore 2*3=6 cases are considered and their results are compared. The debonding initiation load, complete debonding load, crack face profile and load-displacement diagram have been compared for the six cases.

Keywords: fracture, adhesive joint, debonding, APDL, LEFM

Procedia PDF Downloads 386
764 The Awareness of Cardiovascular Diseases among General Population in Western Regions of Saudi Arabia

Authors: Ali Saeed Alghamdi, Basel Mazen Alsolami, Basel Saeed Alghamdi, Muhanad Saleh Alzahrani Alamri, Salman Anwar Thabet, Abdulhalim J. Kinsara

Abstract:

Objectives: This study measures the knowledge of the cardiovascular disease among the general population in western regions of Saudi Arabia, and it aimed to increase the level of awareness about cardiovascular diseases among the general population by providing an awareness lecture that included information about the risk factors, major symptoms, and prevention of cardiovascular diseases. The lecture has been attached at the end of the questionnaire. Setting: This study was conducted through an online questionnaire that included our aim and main objectives that targeted the general population in the Western regions of Saudi Arabia (Makkah and Madinah regions). Participants: This study participants were 460 collected through an online questionnaire. Methods: All Saudi citizens and residents who live in the western region of Saudi Arabia aged 18 years and above will be invited to participate voluntarily. A pre-structured questionnaire was designed to collect data on age, gender, marital status, education level, occupation, lifestyle habits, and history of heart diseases, with cardiac symptoms and risk factors sections. Results: The majority of respondents were females (74.8%) and Saudis. The knowledge about cardiovascular disease risk factors was weak. Only (18.5%) scores an excellent response regarding risk factors awareness. Lack of exercise, stress, and obesity were the most known risk factors. Regarding cardiovascular disease symptoms, chest pain scores the highest symptom (87.6%) among other symptoms like dyspnea, syncope, and excessive sweating. Participants revealed a poor awareness regarding cardiovascular disease symptoms also (0.9%). However, preventable factors for cardiovascular diseases were more knowledgeable than others categories in this study (60% fall into excellent knowledge). Smoking cessation, normal cholesterol level, and normal blood pressure score the highest preventable methods (92.2%), (88.6%), and (78.7%) respectively. 83.7% of the participant have attended the awareness lecture, and 99 of the attendees reported that the lecture increased their knowledge about cardiovascular disease. Conclusion: This study discussed the level of community awareness of cardiovascular disease in terms of symptoms, risk factors, and protective factors. We found a huge lack of the participant's level of knowledge about the disease and how to prevent it. Moreover, we measure the prevalence of the comorbidities among our participants (diabetes, hypertension, hypercholesterolemia/ hypertriglyceridemia) and their extent of adherence to their medication. In conclusion, this study not only demonstrates awareness of cardiovascular disease risk factors, symptoms, management, and the association between each domain but also provides educational material. Further educational material and campaigns are required to increase awareness and knowledge about cardiovascular diseases.

Keywords: awareness, cardiovascular diseases, education, prevention, risk factors

Procedia PDF Downloads 102
763 Acylated Ghrelin in Response to Aerobic Training Induced Weight Loss in Obese Men

Authors: Masoumeh Hosseini

Abstract:

Obesity is known to be associated with cardiovascular diseases and metabolic syndrome. This study aimed to assess the effect of a long term aerobic training program on serum ghrelin in obese men. For this purpose, twenty four sedentary adult obese men aged 30-40 years and body mass index 30-36 kg/m2 were participated in this study and divided randomly into exercise (3 months aerobic training, 3 times/weekly) or control (no training) groups. Serum ghrelin and cardiovascular risk factor (TG, TC, LDL, and HDL) were measured before and after treatment. Anthropometrical markers were measured at two occasions. Data were analyzed by independent-paired T-test. Significance was accepted at P < 0.05. Aerobic training resulted in significant decrease in serum ghrelin and TG in exercise group. All anthropometrical markers decreased significantly in exercise group but not in control subjects. Based on these data, it is concluded that weight loss by aerobic training can be affect serum ghrelin in obese subject, although some cardiovascular risk factor remained without changed.

Keywords: aerobic training, homeostasis, lipid profile, obesity

Procedia PDF Downloads 436
762 Risk Based on Computer Auditing and Measures of ‎Prevention

Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori

Abstract:

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 484
761 Addressing Security and Privacy Issues in a Smart Environment by Using Block-Chain as a Preemptive Technique

Authors: Shahbaz Pervez, Aljawharah Almuhana, Zahida Parveen, Samina Naz, Hira Tariq, Seyed Hosseini, Muhammad Awais Azam

Abstract:

With the latest development in the field of cutting-edge technologies, there is a rapid increase in the use of technology-oriented gadgets. In a recent scenario of the tech era, there is increasing demand to fulfill our day-to-day routine tasks with the help of technological gadgets. We are living in an era of technology where trends have been changing, and a race to introduce a new technology gadget has already begun. Smart cities are getting more popular with every passing day; city councils and governments are under enormous pressure to provide the latest services for their citizens and equip them with all the latest facilities. Thus, ultimately, they are going more into smart cities infrastructure building, providing services to their inhabitants with a single click from their smart devices. This trend is very exciting, but on the other hand, if some incident of security breach happens due to any weaker link, the results would be catastrophic. This paper addresses potential security and privacy breaches with a possible solution by using Blockchain technology in IoT enabled environment.

Keywords: blockchain, cybersecurity, DDOS, intrusion detection, IoT, RFID, smart devices security, smart services

Procedia PDF Downloads 83
760 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 501
759 Optimization of FGM Sandwich Beams Using Imperialist Competitive Algorithm

Authors: Saeed Kamarian, Mahmoud Shakeri

Abstract:

Sandwich structures are used in a variety of engineering applications including aircraft, construction and transportation where strong, stiff and light structures are required. In this paper, frequency maximization of Functionally Graded Sandwich (FGS) beams resting on Pasternak foundations is investigated. A generalized power-law distribution with four parameters is considered for material distribution through the thicknesses of face layers. Since the search space is large, the optimization processes becomes so complicated and too much time consuming. Thus a novel meta–heuristic called Imperialist Competitive Algorithm (ICA) which is a socio-politically motivated global search strategy is implemented to improve the speed of optimization process. Results show the success of applying ICA for engineering problems especially for design optimization of FGM sandwich beams.

Keywords: sandwich beam, functionally graded materials, optimization, imperialist competitive algorithm

Procedia PDF Downloads 542
758 Synchronization of Chaotic T-System via Optimal Control as an Adaptive Controller

Authors: Hossein Kheiri, Bashir Naderi, Mohamad Reza Niknam

Abstract:

In this paper we study the optimal synchronization of chaotic T-system with complete uncertain parameter. Optimal control laws and parameter estimation rules are obtained by using Hamilton-Jacobi-Bellman (HJB) technique and Lyapunov stability theorem. The derived control laws are optimal adaptive control and make the states of drive and response systems asymptotically synchronized. Numerical simulation shows the effectiveness and feasibility of the proposed method.

Keywords: Lyapunov stability, synchronization, chaos, optimal control, adaptive control

Procedia PDF Downloads 447
757 Risk-Based Computer Auditing and Measures of Prevention

Authors: Mohammad Hadi Khorashadi Zadeh, Amin Karkon, Seyd Mohammad Reza Mashhoori ‎

Abstract:

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 453
756 Reliability-Based Life-Cycle Cost Model for Engineering Systems

Authors: Reza Lotfalian, Sudarshan Martins, Peter Radziszewski

Abstract:

The effect of reliability on life-cycle cost, including initial and maintenance cost of a system is studied. The failure probability of a component is used to calculate the average maintenance cost during the operation cycle of the component. The standard deviation of the life-cycle cost is also calculated as an error measure for the average life-cycle cost. As a numerical example, the model is used to study the average life cycle cost of an electric motor.

Keywords: initial cost, life-cycle cost, maintenance cost, reliability

Procedia PDF Downloads 564
755 The Lateral and Torsional Vibration Analysis of a Rotor-Bearing System Using Transfer Matrix Method

Authors: Mohammad Hadi Jalali, Mostafa Ghayour, Saeed Ziaei-Rad, Behrooz Shahriari

Abstract:

The vibration problems that can be occurred in the operational conditions of rotating machines may cause damage to the machine or even failure of the machine completely. Therefore, dynamic analysis of rotors is vital in the design and development stages of the rotating machines. In this study, the uncoupled torsional and lateral vibration analysis of a rotor-bearing system is carried out using transfer matrix method. The Campbell diagram, critical speed and the mode shape corresponding to the critical speed are obtained in order to evaluate the dynamic behavior of the rotor.

Keywords: transfer matrix method, rotor-bearing system, campbell diagram, critical speed

Procedia PDF Downloads 466
754 Eye Diagram for a System of Highly Mode Coupled PMD/PDL Fiber

Authors: Suad M. Abuzariba, Liang Chen, Saeed Hadjifaradji

Abstract:

To evaluate the optical eye diagram due to polarization-mode dispersion (PMD), polarization-dependent loss (PDL), and chromatic dispersion (CD) for a system of highly mode coupled fiber with lumped section at any given optical pulse sequence we present an analytical modle. We found that with considering PDL and the polarization direction correlation between PMD and PDL, a system with highly mode coupled fiber with lumped section can have either higher or lower Q-factor than a highly mode coupled system with same root mean square PDL/PMD values. Also we noticed that a system of two highly mode coupled fibers connected together is not equivalent to a system of highly mode coupled fiber when fluctuation is considered

Keywords: polarization mode dispersion, polarization dependent loss, chromatic dispersion, optical eye diagram

Procedia PDF Downloads 834
753 Assessment of Body Mass Index among Children of Primary School in Behbahan City

Authors: Hosseini Siahi Zohreh, Sana Mohammad Jafar

Abstract:

With increase in fat and over weight in children and its undesirable effects on different organisms of the body and since many of the sicknesses are due to over weight and with losing weight these sicknesses disappear, and on the other hand with mal nutrition and under weight in children other kind of sicknesses such as derogation of body's security system, frequent infection, insufficient growth, shortness, and delay in maturity etc. are some of the signs of being under weight. Therefore recognition of signs of over weight and under weight and their prevalence in children are important. To determine this difficulty we have used the body mass index as screening tool since it is very prevalent and a good and important guide and has very good relation with body fat in children. In this study 2321 students from primary schools in Behbahan have been chosen randomly and evaluated by height and weight and their body mass index have been calculated and then recorded on the BMI percentile diagram which is for age and gender. The following results obtained: The amount of total fat, over weight and slimness are 9.3, 12.1 and 12.32 percent respectively. Therefore 21.4% of the children were over weighted. It did not show any meaningful statistical relation in fat conditions among boys and girls, but there has been a meaningful statistical relation in slimness among boys and girls.

Keywords: assessment, students, Behbahan, Body Mass Index

Procedia PDF Downloads 490