Search results for: Amir Hossein Mohammadi
584 Geometric Continuity in the Form of Iranian Domes, Study of Prominent Safavid and Sasanian Domes
Authors: Nima Valibeig, Haniyeh Mohammadi, Neda Sadat Abdelahi
Abstract:
Persian domes follow different forms depending on the materials used to construct and other factors. One of the factors that shape the form of a dome is the geometric proportion used in the drawing and construction of the dome. Some commonly used proportions are revealed by analysing the shapes and geometric ratio of the monuments’ domes. The proportions are achieved by the proficiency of the skilled architects of the buildings. These proportions can be used to reconstruct damaged parts of the historical monuments. Most of the research on domes is about the historical or stability features of domes, and less attention is made to the geometric system in domes. Therefore, in this study, we study the explicit and implicit geometric proportions in Iranian dome structures for the first time. The study is done based on a literature review and field survey. This research reveals that the permanent geometric rules are perfectly used in the design and construction of the prominent domes.Keywords: geometry in architecture, architectural proportions, prominent domes, iranian golden ratio, geometric proportion
Procedia PDF Downloads 286583 Optimal Voltage and Frequency Control of a Microgrid Using the Harmony Search Algorithm
Authors: Hossein Abbasi
Abstract:
The stability is an important topic to plan and manage the energy in the microgrids as the same as the conventional power systems. The voltage and frequency stability is one of the most important issues recently studied in microgrids. The objectives of this paper are the modelling and designing of the components and optimal controllers for the voltage and frequency control of the AC/DC hybrid microgrid under the different disturbances. Since the PI controllers have the advantages of simple structure and easy implementation, so they are designed and modeled in this paper. The harmony search (HS) algorithm is used to optimize the controllers’ parameters. According to the achieved results, the PI controllers have a good performance in voltage and frequency control of the microgrid.Keywords: frequency control, HS algorithm, microgrid, PI controller, voltage control
Procedia PDF Downloads 391582 Utilization of Bauxite Residue in Construction Materials: An Experimental Study
Authors: Ryan Masoodi, Hossein Rostami
Abstract:
Aluminum has been credited for the massive advancement of many industrial products, from aerospace and automotive to electronics and even household appliances. These developments have come with a cost, which is a toxic by-product. The rise of aluminum production has been accompanied by the rise of a waste material called Bauxite Residue or Red Mud. This toxic material has been proved to be harmful to the environment, yet, there is no proper way to dispose or recycle it. Herewith, a new experimental method to utilize this waste in the building material is proposed. A method to mix red mud, fly ash, and some other ingredients is explored to create a new construction material that can satisfy the minimum required strength for bricks. It concludes that it is possible to produce bricks with enough strength that is suitable for constriction in environments with low to moderate weather conditions.Keywords: bauxite residue, brick, red mud, recycling
Procedia PDF Downloads 169581 Output Voltage Analysis of CMOS Colpitts Oscillator with Short Channel Device
Authors: Maryam Ebrahimpour, Amir Ebrahimi
Abstract:
This paper presents the steady-state amplitude analysis of MOS Colpitts oscillator with short channel device. The proposed method is based on a large signal analysis and the nonlinear differential equations that govern the oscillator circuit behaviour. Also, the short channel effects are considered in the proposed analysis and analytical equations for finding the steady-state oscillation amplitude are derived. The output voltage calculated from this analysis is in excellent agreement with simulations for a wide range of circuit parameters.Keywords: colpitts oscillator, CMOS, electronics, circuits
Procedia PDF Downloads 352580 Consensus-Oriented Analysis Model for Knowledge Management Failure Evaluation in Uncertain Environment
Authors: Amir Ghasem Norouzi, Mahdi Zowghi
Abstract:
This study propose a framework based on the fuzzy T-Norms, T-conorm, a novel operator, and multi-expert approach to help organizations build awareness of the critical influential factors on the success of knowledge management (KM) implementation, analysis the failure of knowledge management. This study considers the complex uncertainty concept that is in knowledge management implementing capability (KMIC) and it is used by fuzzy logic for this reason. The contribution of our paper is shown with an empirical study in a nonprofit educational organization evaluation.Keywords: fuzzy logic, knowledge management, multi expert analysis, consensus oriented average operator
Procedia PDF Downloads 628579 Check Factors Contributing to the Increase or Decrease in Labor Productivity in Employees Applied Science Center Municipal Andimeshk
Authors: Hossein Boromandfar, Ahmad Ghalavandi
Abstract:
This paper examines the importance of human resources as a strategic resource and the factors that lead to increased Labor productivity in Applied Science Center Andimeshk pay. First, the concepts and definitions of productivity and factors affecting it, and then determine the center Recommendations for improving the productivity of the university at a high level its improvement. What leads to increased productivity of labor is worth. The most competent human resources infrastructure is set, because by moving towards the development and promotion. The use of qualified employees in the university with a focus on specific objectives can be effective on its promotion.Keywords: productivity, manage, human resources, center for applied science
Procedia PDF Downloads 418578 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
Abstract:
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 533577 Normal or Abnormal: A Case Study of Jihadi Salafism in the Middle East
Authors: Yusef Karimi, Masoomeh Esmaeily, Razgar Mohammadi
Abstract:
Following the events of September 11th, one of the most important concerns of governments, politicians and, researchers has been to answer the question that why does an ordinary person become fundamentalism? One of the major controversies in past researches was about as to whether a fundamentalist person is normal or abnormal. In this regard, the purpose of this research is to investigate whether a Salafi-jihadi individual is normal or abnormal. The participants included 6 Jihadi Salafism individuals who were living in the Middle East and had been purposefully selected. This research is a qualitative study which examines these people′s retrospective experience of their lives. The data were collected through collaborative observation and interview. This continued till data saturation. Unlike the introduced concepts of fundamentalist personality in the previous studies such as self-fascination, aggression, paranoid personality and psychopathic, participants in this study had no abnormal symptoms of mental disorders. Hence, in the context of recognizing the fundamentalist personality, we must seek other personality and positional variables.Keywords: abnormal, fundamentalism, normal, personality, Salafi
Procedia PDF Downloads 156576 Optimal Temperature and Time for Lactic Coagulation of Milk Containing Antibiotic: Evaluation of Yogurt Fermentation Parameters
Authors: Arezoo Ghadi, Adonis Pishdadian, Ehsan Zahedi, Vahideh Rashedi, Mozhgan Mohammadi
Abstract:
The presence of antibiotics in milk is one of the problems of dairy production units, especially yogurt and cheese, which leads to a decrease in lactic coagulation. Here, to assess the incubation conditions for the fermentation of milk containing antibiotics, concentrations of 50, 75, 100, and 200 ppb of tetracycline were added to each liter of milk. Inoculation process with starter culture performed at three temperatures of 35°C, 45°C, and 50°C. Afterward, pH, acidity, oxidation-reduction potential, and lactic coagulation of yogurt were evaluated. The results showed the existence of antibiotics in milk affects the quality and physicochemical properties of yogurt. However, antibiotic concentration and change in incubation temperature play a crucial role in the lactic coagulation of yogurt, such that the best lactic coagulation was observed at 50°C and a concentration of 50ppb. Hence, for tetracycline concentrations less than 75ppb, a process temperature of 50°C and incubation time of ~10 h recommend for fermentation of milk containing antibiotics.Keywords: antibiotics residues, yogurt, fermentation parameters, incubation temperature
Procedia PDF Downloads 101575 Effect of Deep Mixing Columns and Geogrid on Embankment Settlement on the Soft Soil
Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi
Abstract:
Embankment settlement on soft clays has always been problematic due to the high compaction and low shear strength of the soil. Deep soil mixing and geosynthetics are two soil improvement methods in such fields. Here, a numerical study is conducted on the embankment performance on the soft ground improved by deep soil mixing columns and geosynthetics based on the data of a real project. For this purpose, the finite element method is used in the Plaxis 2D software. The Soft Soil Creep model considers the creep phenomenon in the soft clay layer while the Mohr-Columb model simulates other soil layers. Results are verified using the data of an experimental embankment built on deep mixing columns. The effect of depth and diameter of deep mixing columns and the stiffness of geogrid on the vertical and horizontal movements of embankment on clay subsoil will be investigated in the following.Keywords: PLAXIS 2D, embankment settlement, horizontal movement, deep soil mixing column, geogrid
Procedia PDF Downloads 175574 Micro-CT Imaging Of Hard Tissues
Authors: Amir Davood Elmi
Abstract:
From the earliest light microscope to the most innovative X-ray imaging techniques, all of them have refined and improved our knowledge about the organization and composition of living tissues. The old techniques are time consuming and ultimately destructive to the tissues under the examination. In recent few decades, thanks to the boost of technology, non-destructive visualization techniques, such as X-ray computed tomography (CT), magnetic resonance imaging (MRI), selective plane illumination microscopy (SPIM), and optical projection tomography (OPT), have come to the forefront. Among these techniques, CT is excellent for mineralized tissues such as bone or dentine. In addition, CT it is faster than other aforementioned techniques and the sample remains intact. In this article, applications, advantages, and limitations of micro-CT is discussed, in addition to some information about micro-CT of soft tissue.Keywords: Micro-CT, hard tissue, bone, attenuation coefficient, rapid prototyping
Procedia PDF Downloads 143573 Phytoremediation Potential of Tomato for Cd and Cr Removal from Polluted Soils
Authors: Jahanshah Saleh, Hossein Ghasemi, Ali Shahriari, Faezeh Alizadeh, Yaaghoob Hosseini
Abstract:
Cadmium and chromium are toxic to most organisms and different mechanisms have been developed for overcoming with the toxic effects of these heavy metals. We studied the uptake and distribution of cadmium and chromium in different organs of tomato (Lycopersicon esculentum L.) plants in nine heavy metal polluted soils in western Hormozgan province, Iran. The accumulation of chromium was in increasing pattern of fruit peelKeywords: cadmium, chromium, phytoextraction, phytostabilization, tomato
Procedia PDF Downloads 349572 Physical and Psychosocial Risk Factors Associated with Occupational Lower Back/Neck Pain among Industrial Workers
Authors: Ghorbanali Mohammadi
Abstract:
Background: The objectives of this study were the association between physical and psychological risk factors for occupational lower back and neck pain among industrial workers. Methods: We conducted a cross-sectional study among 400 male workers of an industrial company over the previous 7days and 12 months. Data were collected using Nordic and third version of COPSOO questionnaires and QEC method for assessment of postures during the work. Results: The prevalence of LB and NP in the last 12 months is 58% and 52% respectively. The relationship between risk factors and low back/ neck pain in the last 12 months were cognitive demands (OR 995% CI 1.65) and (OR 995% CI 1.75); Influence at work (OR 995% CI 2.21) and (OR 995% CI 1.85); quality of leadership (OR 995% CI 2.42) and (OR 995% CI 2.09) was strongly correlated with complaints of low back and neck pains. Conclusion: Data of this study showed a higher prevalence of LBP and NP in the subjects. The results revealed that workers with work experience of more than 12 yrs. and who work more than 8 hrs. days with smoking habits had more probability to develop both LBP and NP.Keywords: low back pain, neck pain, physical risk factors, psychological risk factors, QEC, COPSOQ III
Procedia PDF Downloads 92571 A Hyperexponential Approximation to Finite-Time and Infinite-Time Ruin Probabilities of Compound Poisson Processes
Authors: Amir T. Payandeh Najafabadi
Abstract:
This article considers the problem of evaluating infinite-time (or finite-time) ruin probability under a given compound Poisson surplus process by approximating the claim size distribution by a finite mixture exponential, say Hyperexponential, distribution. It restates the infinite-time (or finite-time) ruin probability as a solvable ordinary differential equation (or a partial differential equation). Application of our findings has been given through a simulation study.Keywords: ruin probability, compound poisson processes, mixture exponential (hyperexponential) distribution, heavy-tailed distributions
Procedia PDF Downloads 341570 Tree Species Classification Using Effective Features of Polarimetric SAR and Hyperspectral Images
Authors: Milad Vahidi, Mahmod R. Sahebi, Mehrnoosh Omati, Reza Mohammadi
Abstract:
Forest management organizations need information to perform their work effectively. Remote sensing is an effective method to acquire information from the Earth. Two datasets of remote sensing images were used to classify forested regions. Firstly, all of extractable features from hyperspectral and PolSAR images were extracted. The optical features were spectral indexes related to the chemical, water contents, structural indexes, effective bands and absorption features. Also, PolSAR features were the original data, target decomposition components, and SAR discriminators features. Secondly, the particle swarm optimization (PSO) and the genetic algorithms (GA) were applied to select optimization features. Furthermore, the support vector machine (SVM) classifier was used to classify the image. The results showed that the combination of PSO and SVM had higher overall accuracy than the other cases. This combination provided overall accuracy about 90.56%. The effective features were the spectral index, the bands in shortwave infrared (SWIR) and the visible ranges and certain PolSAR features.Keywords: hyperspectral, PolSAR, feature selection, SVM
Procedia PDF Downloads 419569 Facile Synthesis of Copper Based Nanowires Suitable for Lithium Ion Battery Application
Authors: Zeinab Sanaee, Hossein Jafaripour
Abstract:
Copper is an excellent conductive material that is widely used in the energy devices such as Lithium-ion batteries and supercapacitors as the current collector. On the other hand, copper oxide nanowires have been used in these applications as potential electrode material. In this paper, nanowires of Copper and Copper oxide have been synthesized through a simple and time and cost-effective approach. The thermally grown Copper oxide nanowires have been converted into Copper nanowires through annealing in the Hydrogen atmosphere in a DC-PECVD system. To have a proper Copper nanostructure formation, an Au nanolayer was coated on the surface of Copper oxide nanowires. The results show the successful achievement of Copper nanowires without deformation or cracking. These structures have a great potential for Lithium-ion batteries and supercapacitors.Keywords: Copper, Copper oxide, nanowires, Hydrogen annealing, Lithium ion battery
Procedia PDF Downloads 87568 Investigation of the Aerodynamic Characteristics of a Vertical Take-Off and Landing Mini Unmanned Aerial Vehicle Configuration
Authors: Amir Abdelqodus, Mario Shehata
Abstract:
The purpose of the paper is to model and evaluate the aerodynamic coefficients and stability derivatives of a Vertical, Take-off and Landing Unmanned Aerial Vehicle configuration (VTOL UAV), which is a fixed wing UAV and a quad-copter hybrid capable of both vertical and conventional take-off and/or landing. The aerodynamic analysis of this configuration was carried out using CFD commercial package Ansys Fluent. Also, the aerodynamic coefficients for the case of the UAV without the quad-copter is carried out analytically using MATLAB programmed codes, and the resulting data is verified using Lifting Line Theory and potential method programs. The two results are then compared to understand the effect of adding the quad-copter on the aerodynamic performance of the UAV.Keywords: aerodynamics, CFD, potential flow, UAV, VTOL
Procedia PDF Downloads 446567 Effect of Cloud Computing on Enterprises
Authors: Amir Rashid
Abstract:
Today is the world of innovations where everyone is looking for a change. Organizations are now looking toward virtualization in order to minimize their computing cost. Cloud Computing has also introduced itself by the means of reducing computing cost. It offers different approach to make computing better by improving utilization and reducing infrastructure and administrative costs. Cloud Computing is basically the amalgamation of Utility Computing and SaaS (Software as a Service). Cloud Computing is quite new to organizations as it is still at its deploying stage. Due to this reason, organizations are not confident whether to adopt it or not. This thesis investigates the problem for organization concerning the security and cost issues. Benefits and drawbacks are being highlighted which organizations can have or suffer in order to adopt Cloud Computing. In Conclusion, Cloud Computing is a better option available for small and medium organizations with a comparison to large companies both in terms of data security and cost.Keywords: cloud computing, security, cost, elasticity, PaaS, IaaS, SaaS
Procedia PDF Downloads 342566 The Necessity and Methods of Abolishing Discrimination and Religious Violence
Authors: Hossein Boroujerdi, Mohammad R. Sadeghi, Maryam Moazen Zadeh
Abstract:
During the recent decades, the result of religious prophets has lost its attraction, and theology has become disfigured, so it has been made ugly. Undoubtedly, some of existing non-peaceful and harsh rules and measures within the religious books and contexts have been considered as the reasons and excuses for defamation of religions. Based on library sources and also extensive research in Quran and Islamic narratives, this study has aimed to find some alternative solutions and options to abolish and disregard those religious rules which are in contrary of human right charters and standards. The results have demonstrated that some of inhuman religious punishments such as execution, stoning, whipping as well as religious discriminations and warlike behaviors are in contrary of some other religious contexts and concepts. This finding have proved inadaptability between some religious contexts and religious records.Keywords: adjustment and abolishment, discrimination, religious commands and laws, tolerance, violence
Procedia PDF Downloads 215565 The Indo-European and Old Iranian Fire and Its Relations with the Lur Fire
Authors: Behzad Moeini Sam, Sara Mohammadi Avandi
Abstract:
The rituals of fire among the Iranians go back to the general Proto-Indo-European and Indo-Iranian eras when they lived in regions known as the Pontic-Caspian (Indo-Europeans) and Kazakhstan (the Andronovo culture belonging to the Indo-Iranian tribes), and we can get to know about their vulgar heritage despite their separation from each other during several millennia. The early Aryan settlers of Iran had brought their cults to their new home and were bequeathed to them by their Indo-Iranian ancestors. Tradition speaks of several great sacred Iranian fires consecrated by the pre-Zoroastrian kings. Ātar or fire corresponds to the Vedic Agni Atar's functions are elaborately delineated in the Later Avesta. This paper aims to show the fire cults among the Iranian Lur tribes that originate in the past. Therefore, it will be searched for rituals in equally Indo-European and Indo-Iranian Periods and Old Iranian Texts and their frequency among the Lur tribes. In addition to the library books, we tried to interview the chiefs of Lur tribes. Finally, we concluded that the fire among the Lur Tribes is a sequence of beliefs of the Proto-Indo-European and Indo-Iranian Periods reflected in Old and Middle Iranian texts.Keywords: Indo-European, ancient Iran, fire, Lur, Zoroastrian
Procedia PDF Downloads 86564 Neutronic Calculations for Central Test Loop in Heavy Water Research Reactor
Authors: Hadi Shamoradifar, Behzad Teimuri, Parviz Parvaresh, Saeed Mohammadi
Abstract:
One of the experimental facilities of the heavy water research reactor is the central test loop (C.T.L). It is located along the central axial line of the vessel, and therefore will highly affect the neutronic parameters of the reactor, so from the neutronics point of view, C.T.L is the most important facility. It is mainly designed for fuel testing, thought other applications such as radioisotope production and neutron activation, can be imagine for it. All of the simulations were performed by MCNPX2.6. As a first step towards C.T.L analysis, the effect of D2O-filled, H2O-filled, and He-filled C.T.L on the effective multiplication factor (Keff.), have been evaluated. According to results, H2O-filled C.T.L has a higher thermal neutron, while He-filled C.T.L includes more resonance neutrons. In the next step thermal and total axial neutron fluxes, were calculated and used as the comparison parameters. The core without C.T.L (C.T.L replaced by heavy water) is selected as the reference case, and the effect of all other cases is calculated according to that.Keywords: heavy water reactor, neutronic calculations, central test loop, neutron activation
Procedia PDF Downloads 364563 Investigation of the Effect of Nickel Electrodes as a Stainless Steel Buffer Layer on the Shielded Metal Arc Welding
Authors: Meisam Akbari, Seyed Hossein Elahi, Mohammad Mashadgarmeh
Abstract:
In this study, the effect of nickel-electrode as a stainless steel buffer layer is considered. Then, the effect of dilution of the last layer of welding on two samples of steel plate A516 Gr70 (C-Mn-Si) with SMAW welding process was investigated. Then, in a sample, the ENI-cl nickel electrode was welded as the buffer layer and the E316L-16 electrode as the last layer of welding and another sample with an E316L-16 electrode in two layers. The chemical composition of the latter layer was determined by spectrophotometry method. The results indicate that the chemical composition of the latter layer is different and the lowest dilution rate is obtained using the nickel electrode.Keywords: degree of dilution, C-Mn-Si, spectrometry, nickel electrode, stainless steel
Procedia PDF Downloads 220562 Membranes for Direct Lithium Extraction (DLE)
Authors: Amir Razmjou, Elika Karbassi Yazdi
Abstract:
Several direct lithium extraction (DLE) technologies have been developed for Li extraction from different brines. Although laboratory studies showed that they can technically recover Li to 90%, challenges still remain in developing a sustainable process that can serve as a foundation for the lithium dependent low-carbon economy. There is a continuing quest for DLE technologies that do not need extensive pre-treatments, fewer materials, and have simplified extraction processes with high Li selectivity. Here, an overview of DLE technologies will be provided with an emphasis on the basic principles of the materials’ design for the development of membranes with nanochannels and nanopores with Li ion selectivity. We have used a variety of building blocks such as nano-clay, organic frameworks, Graphene/oxide, MXene, etc., to fabricate the membranes. Molecular dynamic simulation (MD) and density functional theory (DFT) were used to reveal new mechanisms by which high Li selectivity was obtained.Keywords: lithium recovery, membrane, lithium selectivity, decarbonization
Procedia PDF Downloads 112561 Soil Mass Loss Reduction during Rainfalls by Reinforcing the Slopes with the Surficial Confinement
Authors: Ramli Nazir, Hossein Moayedi
Abstract:
Soil confinement systems serve as effective solutions to any erosion control project. Various confinements systems, namely triangular, circular and rectangular with the size of 50, 100, and 150 mm, and with a depth of 10 mm, were embedded in soil samples at slope angle of 60°. The observed soil mass losses for the confined soil systems were much smaller than those from unconfined system. As a result, the size of confinement and rainfall intensity have a direct effect on the soil mass loss. The triangular and rectangular confinement systems showed the lowest and highest soil loss masses, respectively. The slopes also failed much faster in the unconfined system than in the confined slope.Keywords: erosion control, soil confinement, soil erosion, slope stability
Procedia PDF Downloads 842560 Designing a Tool for Software Maintenance
Authors: Amir Ngah, Masita Abdul Jalil, Zailani Abdullah
Abstract:
The aim of software maintenance is to maintain the software system in accordance with advancement in software and hardware technology. One of the early works on software maintenance is to extract information at higher level of abstraction. In this paper, we present the process of how to design an information extraction tool for software maintenance. The tool can extract the basic information from old program such as about variables, based classes, derived classes, objects of classes, and functions. The tool have two main part; the lexical analyzer module that can read the input file character by character, and the searching module which is user can get the basic information from existing program. We implemented this tool for a patterned sub-C++ language as an input file.Keywords: extraction tool, software maintenance, reverse engineering, C++
Procedia PDF Downloads 492559 Defining Affecting Factors on Rate of Car E-Customers' Satisfaction – a Case Study of Iran Khodro Co.
Authors: Majid Mohammadi, Mohammad Yosef Zadeh, Vahid Naderi Darshori
Abstract:
The main purpose of this research is concreting of satisfaction literature for obtain index with online content in carmaker industry. The study measures customer satisfaction of online and collect from similar studies with reference to a model of online satisfaction, they are attempting to complete. Statistical communities of research are online customers' carmaker Iran Khodro has been buying the company's products in the last six months. One of the innovative measures in this study is that, customer reviews are obtained through an Internet site. Reliability of the data collected in this study, the Cronbach's alpha coefficient was approved. The coefficient of 0.828 was calculated for the questionnaire. To test the hypothesis, the Pearson correlation coefficient was used. To ensure the correctness of initial theoretical model, we used regression analyzes and structural equation weight and finally, the results obtained with little change to the basic model of research, are improved and completed. At last obtain the perceived value has most direct effect on online car customers satisfaction.Keywords: customer satisfaction, online satisfaction, online customer, car
Procedia PDF Downloads 405558 Numerical Study of Natural Convection of a Localized Heat Source at the up of a Nanofluid-Filled Enclosure
Authors: Marziyeh Heydari, Hossein Shokouhmand
Abstract:
This article presents a numerical study of natural convection of a heat source embedded on the up wall of an enclosure filled with nanofluid. The bottom and vertical walls of the enclosure are maintained at a relatively low temperature. The type of nanofluid and solid volume fraction of nanoparticle on the heat transfer performance is studied. The results indicated that adding nanoparticle into pure paraffin improves heat transfer. The results are presented over a wide range of Rayleigh numbers(Ra=〖10〗^3 〖-10〗^5), the volume fraction of nanoparticles (0≤ɸ≤0.4%). For an enclosure, the Nusselt number of a cu-paraffin nanofluid was reduced by increasing the volume fraction of nanoparticles above 0.2%.Keywords: nanofluid, heat transfer, heat source, enclosure
Procedia PDF Downloads 310557 Seismic Investigation on the Effect of Surface Structures and Twin Tunnel on the Site Response in Urban Areas
Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi
Abstract:
Site response has a profound effect on earthquake damages. Seismic interaction of urban tunnels with surface structures could also affect seismic site response. Here, we use FLAC 2D to investigate the interaction of a single tunnel and twin tunnels-surface structures on the site response. Soil stratification and properties are selected based on Line. No 7 of the Tehran subway. The effect of surface structure is considered in two ways: Equivalent surcharge and geometrical modeling of the structure. Comparison of the results shows that consideration of the structure geometry is vital in dynamic analysis and leads to the changes in the magnitude of displacements, accelerations and response spectrum. Therefore it is necessary for the surface structures to be wholly modeled and not just considered as a surcharge in dynamic analysis. The use of twin tunnel also leads to the reduction of dynamic residual settlement.Keywords: superstructure, tunnel, site response, surcharge, interaction
Procedia PDF Downloads 166556 Effect of IGF-I on Ovine Oocytes Maturation and Subsequent Embryo Development following in Vitro Fertilization (IVF)
Authors: Babak Qasemi-Panahi, Gholamali Moghaddam, Seyed-Abbas Rafat, Hossein Daghigh Kia, Mansoureh Movahedin, Reza Hadavi
Abstract:
The objective of this study was to determine the effects of IGF-I on ovine oocytes maturation and subsequent development of embryos derived from in vitro fertilization (IVF). In vitro maturation (IVM) of oocytes and in vitro culture (IVC) of embryos was conducted with or without 100 ng/mL IGF-1. In the IGF-I treated group, mean percentage of oocyte maturation was significantly higher than the control group (57.67 ± 3.04 versus 49.81 ± 3.04%, respectively, P < 0.05). However, in comparison with control group, there was no significant effect of IGF-1 on rates of cleavage, morula, and blastocyst formation (85% versus 84%; 63% versus 65%, and 40% to 39%, respectively). These data demonstrate that IGF-I has a positive effect on ovine oocyte maturation rate, but it has not the significant outcome on embryo development.Keywords: ovine, IGF-I, IVM, ICSI
Procedia PDF Downloads 689555 Investigating the Effects of Hydrogen on Wet Cement for Underground Hydrogen Storage Applications in Oil and Gas Wells
Authors: Hamoud Al-Hadrami, Hossein Emadi, Athar Hussain
Abstract:
Green hydrogen is quickly emerging as a new source of renewable energy for the world. Hydrogen production using water electrolysis is deemed as an environmentally friendly and safe source of energy for transportation and other industries. However, storing a high volume of hydrogen seems to be a significant challenge. Abandoned hydrocarbon reservoirs are considered as viable hydrogen storage options because of the availability of the required infrastructure such as wells and surface facilities. However, long-term wellbore integrity in these wells could be a serious challenge. Hydrogen reduces the compressive strength of a set cement if it gets in contact with the cement slurry. Also, mixing hydrogen with cement slurry slightly increases its density and rheological properties, which need to be considered to have a successful primary cementing operation.Keywords: hydrogen, well bore integrity, clean energy, cementing
Procedia PDF Downloads 216