Search results for: Seyyed Hamid Ahmadi

Authors: Parisa Ahmadi Oliaei, Seyed Abolhassan Naeini

Abstract:

The knowledge of soil–reinforcement interaction parameters is particularly important in the design of reinforced soil structures. The pull-out test is one of the most widely used tests in this regard. The results of tensile tests may be very sensitive to boundary conditions, and more research is needed for a better understanding of the Pull-out response of reinforcement, so numerical analysis using the finite element method can be a useful tool for the understanding of the Pull-out response of soil-geogrid interaction. The main objective of the present study is to compare the numerical and experimental results of Pull- out a test on geogrid-reinforced sandy soils interactions. Plaxis 2D finite element software is used for simulation. In the present study, the pull-out test modeling has been done on sandy soil. The effect of geogrid hardness was also investigated by considering two different types of geogrids. The numerical results curve had a good agreement with the pull-out laboratory results.

Keywords: plaxis, pull-out test, sand, soil- geogrid interaction

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Authors: Salah Al-Din I. Badran, Samad Ahmadi, Ismail Shahin

Abstract:

A blind source separation method is proposed; in this method we use a non-uniform filter bank and a novel normalisation. This method provides a reduced computational complexity and increased convergence speed comparing to the full-band algorithm. Recently, adaptive sub-band scheme has been recommended to solve two problems: reduction of computational complexity and increase the convergence speed of the adaptive algorithm for correlated input signals. In this work the reduction in computational complexity is achieved with the use of adaptive filters of orders less than the full-band adaptive filters, which operate at a sampling rate lower than the sampling rate of the input signal. The decomposed signals by analysis bank filter are less correlated in each sub-band than the input signal at full bandwidth, and can promote better rates of convergence.

Keywords: blind source separation, computational complexity, subband, convergence speed, mixture

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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

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Authors: Amin Chegenizadeh, Mahdi Keramatikerman, Hamid Nikraz

Abstract:

Pavement engineering plays a significant role to develop cost effective and efficient highway and road networks. In general, pavement regarding structure is categorized in two core group namely flexible and rigid pavements. There are various benefits in application of rigid pavement. For instance, they have a longer life and lower maintenance costs in compare with the flexible pavement. In rigid pavement designs, temperature and thickness are two effective parameters that could widely affect the total cost of the project. In this study, a numerical modeling using Kenpave-Kenslab was performed to investigate the effect of these two important parameters in the rigid pavement.   

Keywords: rigid pavement, Kenpave, Kenslab, thickness, temperature

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Authors: Saeedeh Ahmadi Basir, Mohammad Mahdavi Mazdeh, Mohammad Namakshenas

Abstract:

Manufacturers often dispatch jobs in batches to reduce delivery costs. However, sending several jobs in batches can have a negative effect on other scheduling-related objective functions such as minimizing the number of tardy jobs which is often used to rate managers’ performance in many manufacturing environments. This paper aims to minimize the number of weighted tardy jobs and the sum of delivery costs of a two-stage assembly flow-shop problem in a batch delivery system. We present a mixed-integer linear programming (MILP) model to solve the problem. As this is an MILP model, the commercial solver (the CPLEX solver) is not guaranteed to find the optimal solution for large-size problems at a reasonable amount of time. We present several numerical examples to confirm the accuracy of the model.

Keywords: scheduling, two-stage assembly flow-shop, tardy jobs, batched delivery system

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Authors: Naser Ahmadi Sani, Karim Solaimani, Lida Razaghnia, Jalal Zandi

Abstract:

In recent decades, rapid and incorrect changes in land-use have been associated with consequences such as natural resources degradation and environmental pollution. Detecting changes in land-use is one of the tools for natural resource management and assessment of changes in ecosystems. The target of this research is studying the land-use changes in Haraz basin with an area of 677000 hectares in a 15 years period (1996 to 2011) using LANDSAT data. Therefore, the quality of the images was first evaluated. Various enhancement methods for creating synthetic bonds were used in the analysis. Separate training sites were selected for each image. Then the images of each period were classified in 9 classes using supervised classification method and the maximum likelihood algorithm. Finally, the changes were extracted in GIS environment. The results showed that these changes are an alarm for the HARAZ basin status in future. The reason is that 27% of the area has been changed, which is related to changing the range lands to bare land and dry farming and also changing the dense forest to sparse forest, horticulture, farming land and residential area.

Keywords: Haraz basin, change detection, land-use, satellite data

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Authors: Seyyed Mohammad Amin Mousavi Sagharchi, Alireza Mahmoudi Nasab, Tim Bakker

Abstract:

Introduction: Mycobacterium tuberculosis (MTB) is the most intelligent bacterium that existed in the world to our best knowledge. This bacterium can cause tuberculosis (TB) which is responsible for its spread speed and murder of millions of people around the world. MTB has the practical function to escape from anti-tuberculosis drugs (AT), for this purpose, it handles some mutations in the main genes and creates new patterns for inhibited genes. Method and materials: Researchers have their best tries to safely isolate MTB from the sputum specimens of 35 patients in some hospitals in the Tehran province and detect MTB by culture on Löwenstein-Jensen (LJ) medium and microscopic examination. DNA was extracted from the established bacterial colony by enzymatic extraction method. It was amplified by the polymerase chain reaction (PCR) method, reverse hybridization, and evaluation for detection of resistance genes; generally, researchers apply GenoType MTBDRplus assay. Results: Investigations of results declare us that 21 of the isolated specimens (about 60%) have mutation in rpoB gene, which resisted to rifampicin (most prevalence), and 8 of them (about 22.8%) have mutation in katG or inhA genes which resisted to isoniazid. Also, 4 of them (about 11.4%) don't have any mutation, and 2 of them (about 5.7%) have mutation in every three genes, which makes them resistant to the two drugs mentioned above. Conclusion: Rifampicin and isoniazid are two essential AT that using in the first line of treatment. Resistance in rpoB, and katG, and inhA genes related to mentioned drugs lead to ineffective treatment.

Keywords: mycobacterium tuberculosis, tuberculosis, drug resistance, isoniazid, rifampicin

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Authors: R. Rajabpour, N. Talebbeydokhti, M. H. Ahmadi

Abstract:

In recent years, new techniques for solving complex problems in engineering are proposed. One of these techniques is JPSO algorithm. With innovative changes in the nature of the jump algorithm JPSO, it is possible to construct a graph-based solution with a new algorithm called G-JPSO. In this paper, a new algorithm to solve the optimal control problem Fletcher-Powell and optimal control of pumps in water distribution network was evaluated. Optimal control of pumps comprise of optimum timetable operation (status on and off) for each of the pumps at the desired time interval. Maximum number of status on and off for each pumps imposed to the objective function as another constraint. To determine the optimal operation of pumps, a model-based optimization-simulation algorithm was developed based on G-JPSO and JPSO algorithms. The proposed algorithm results were compared well with the ant colony algorithm, genetic and JPSO results. This shows the robustness of proposed algorithm in finding near optimum solutions with reasonable computational cost.

Keywords: G-JPSO, operation, optimization, pumping station, water distribution networks

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Authors: Fatemeh Ansarniya, Fatemeh Mirjalili, Hamid Reza Abedini, Shabnam Salari, M. Horasht

Abstract:

The study of this research is the effect of using Fe₂O₃ and sum of alkalis elements in the floor tile production. At first, raw materials of floor tile with the same formulation of original sample was prepared and sintered for 39 minutes at 1130˚C in roller kiln and finally, physical properties of the sintered bodies based on floor tile standard process was investigated. The results showed that there was the possibility of production of floor tile containing different percentages of Fe₂O₃ and sum of Na₂O+ K₂O. With increasing the Fe₂O₃ and sum of Na₂O+ K₂O elements, the percentages of water absorption and raw, dry and sintered strengths were decreased, but the percentages of shrinkage were increased which caused the decreasing the percentages of expansion.

Keywords: floor tile, physical properties, Na2O+ K2O, Fe2O3

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Authors: Hamid Chaikhy, Mouna Essaadi, Aziz El Afia

Abstract:

This paper presents an experimental implementation of a new direct torque control strategy of induction machine called twelve sectors direct torque control strategy (12_DTC) using DSPACE TMS 320F2812.The aim of this work is to give an experimental performance analysis of 12_DTC in term of torque, currents distortions and stator flux, to validate simulation results obtained in previous works.

Keywords: 12_DTC, DSPACE TMS 320F2812 torque, stator flux, currents distortions, experimental performance analysis

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Authors: Mahdi Momeni

Abstract:

The arrival of Mysticism to the subcontinent can be generally divided into two periods. The first period, was the Sporadic arrival of Sufis whom were traveling to the subcontinent according to the tradition of disquisition and the second period was; when the Sufi dynasties were sending missionaries and caliphs to guide and promote people from different direction to that land. Among the Sufi dynasty that entered to India in the thirteenth century, two dynasties of Chishti and Suhrawardîya were more successful than other Sufi dynasties. And thus they are very important in the spread of Islam and Mysticism to the subcontinent. Suhrawardiyya dynasty was founded by Sheikh Ziauddin Abu Najib Suhrawardi and was developed and spread by his nephew Sheikh Shahabuddin Suhrawardi Abo hafs Omar. Sheikh Shahabuddin sent many Caliphs and missionaries to India. Among these missionaries were People like Sultan Sakhi Sarwar, Seyyed Noureddin Mobarak Ghaznavi, Sheikh Jalal al-din Tabrizi and Sheikh Zakariya Multani. Since Suhrawardiyya doctrine relies on Asceticism and Sharia, so one of the important elements among Suhrawardiyya missionaries was inviting people to Islam. Accordingly Sheikh Shahab Caliphs had a great role in the spread of Islam and Mysticism in different territories, especially India. Such that it can be pointed out is the the role of Sheikh Baha-ud-din Zakariya Multani, the founder of Suhrawardiyya Dynasty in India. Sheikh Zakaria Multani after working in three areas, establishing monasteries, training managers, having numerous trips to different places, participating to social affairs provided the spread of Islam and Mysticism in subcontinent. This paper studies his role and actions in the subcontinent.

Keywords: islam, sufism, Suhrawardiyya, subcontinent, Multan

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Authors: Mohammad Reza Boroumand Devlagh, Seyed Mohammad Hosein Razavi, Fatemeh Ahmadi, Azam Fazli Darzi

Abstract:

The issue of female presence in Iran stadiums has long been considered and debated by governmental experts and authorities, however, no conclusion is yielded yet. Thus, the present study has been done with the aim of investigating the approach of male and female spectators about the presence of female spectators in Iranian stadiums. The statistical population of the study includes all male and female spectators who have not experienced the live watching of male championship matches in stadiums. 224 subjects from the statistical population have selected through stratified random sampling as the sample of the study. For data collection, researcher-made questionnaire has been used whose validity has been confirmed by the university professors and its reliability has been studied and confirmed through an preliminary study. (r= 0.81). Data analysis has been done using descriptive and referential statistics in P< 0.05. The results of the study showed that male and female were meaningfully agreed with the female presence in stadiums and there is no meaningful difference between male and female approaches concerning the female spectators’ presence in sport stadiums of Iran (sig= 0.867).

Keywords: male, female spectators, Iran, sport stadiums, population

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Authors: Bita Mashayekhi, Hamid Kalhornia

Abstract:

One of the most important roles of financial reporting is improving the firms’ investment decisions; however, there is not much supporting evidence for this claim in emerging markets like Iran. In this study, the effect of financial reporting transparency in investment efficiency of Iranian firms has been investigated. In order to do this, 336 listed companies on Tehran Stock Exchange (TSE) has been selected for time period 2012 to 2015 as research sample. For testing our main hypothesis, we classified sample firms into two groups based on their deviation from expected investment: under-investment and over-investment cases. The results indicate that there is positive significant relationship between financial transparency and investment efficiency. In the other words, transparency can mitigate both underinvestment and overinvestment situations.

Keywords: corporate governance, disclosure, investment decisions, investment efficiency, transparency

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Authors: Hamid Mohammadi, S. H. Eftekhar Afzali

Abstract:

The irregular usage of chemical fertilizer cause different types of water and soil pollution and problems in health of human in past decades and organic fertilizer has been considered more and more. Mycorrhizal fungi have symbiosis with plant families and significantly effect on plant growth. Proper management of these symbiosis causes to reduce the usage of chemical fertilizers and absorb nutrition especially phosphor. Pistacia vera is endemic in Iran and is one of the most important products for this country. Considering special circumstances of pistachio orchards according to increasing salinity of water and soil and mismanagement of fertilizer reveals the necessity of the usage of Mycorrhizal fungi in these orchards.

Keywords: pistachio, mycorhiza, nutrition, salinity

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Authors: Abdul Rashid Ahmadi, Samiullah Paracha, Hamidullah Sokout, Mohammad Hanif Gharana

Abstract:

Conventional educational practices, do not offer all the required skills for teachers to successfully survive in today’s workplace. Due to poor professional training, a big gap exists across the curriculum plan and the teacher practices in the classroom. As such, raising the quality of teaching through ICT-enabled training and professional development of teachers should be an urgent priority. ‘Mobile Learning’, in that vein, is an increasingly growing field of educational research and practice across schools and work places. In this paper, we propose a novel Mobile learning system that allows the users to learn through an intelligent mobile learning in cooperatively every-time and every-where. The system will reduce the training cost and increase consistency, efficiency, and data reliability. To establish that our system will display neither functional nor performance failure, the evaluation strategy is based on formal observation of users interacting with system followed by questionnaires and structured interviews.

Keywords: computer assisted learning, intelligent tutoring system, learner centered design, mobile mediated learning and teacher education

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Authors: Seyyed Javad Ziaolhagh

Abstract:

Background: The purpose of present study was to investigate, the effects of anabolic steroid Boldenone (BOL) with eight weeks of resistance training on structural changes in rat liver. Method: 21 Male adult Wistar rats, 12 weeks old and 228/53±7/94 g initial body weight were randomly assigned to three groups: group1: Control+ Placebo (C), group2: training+ Placebo (T), group3: Boldenone intramuscular injections 5mg/kg (B). The endurance training protocol consisted three exercise sessions weekly started by a 30-minute run with the speed of 12 m/min and lasted by 60min run with the speed of 30 m/min in 8 weeks. At the end of the experiment, for light microscopic study Slides were prepared. Results: Sections stained of rat's livers showed no any cell degeneration and cytoplasmic lipid vacuoles in all groups, but few samples were seen. Indeed, congested blood sinusoids, cell infiltration and degeneration were seen in the Boldenone-treated group. Hepatotoxic effects were severe in group treatment received 5 mg/kg and directly depended on the doses. Indeed, training group was no any hepatocyte degeneration, inflammation and congestion. Conclusion: The present results showed that BOL has a marked adverse effect on the liver tissue, even with low– dose and endurance training. As a result, athletes should aware of Boldenone dosage consumption.

Keywords: anabolic androgenic steroids, Boldenone, blood congestion, cellular inflammation, cellular degeneration, lipid vocuolations, endurance training

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Authors: Ahmed Khalil

Abstract:

The discoveries in material sciences create an impulse in renewable energy transmission. Application techniques become more accessible by applied sciences. Variety of materials, application methods, and performance analyzing techniques can convert daily life functions to energy sources. These functions not only include natural sources like sun, wind, or water but also comprise the motion of tools used by human beings. In line with this, vehicles' motion, speed and weights come to the scene as energy sources together with piezoelectric nano-generators beneath the roads. Numerous application examples are put forward with repeated average performance, versus the differentiating challenges depending on geography and project conditions. Such holistic approach provides way for feed backs on research and improvement process of nano-generators beneath asphalt roads. This paper introduces the specific application methods of piezoelectric nano-generator beneath asphalt roads of Ahmadi Township in Kuwait.

Keywords: nano-generator pavements, piezoelectric, renewable energy, transducer

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Authors: Hamid Gholami

Abstract:

During the years, the language teaching methods have been the offshoots of schools of thought in psychology. The methods were mainly influenced by their contemporary psychological approaches, as Audiolingualism was based on behaviorism and Communicative Language Teaching on constructivism. In 1950s, the text books were full of repetition exercises which were encouraged by Behaviorism. In 1980s they got filled with communicative exercises as suggested by constructivism. The trend went on to nowadays that sees no specific method as prevalent since none of the schools of thought seem to be illustrative of the complexity in human being learning. But some changes can be notable; some textbooks are giving more and more space to repetition exercises at least to enhance some aspects of language proficiency, namely collocations, rhythm and intonation, and conversation models. These changes may mark the reemergence of one of the once widely accepted schools of thought in psychology; behaviorism.

Keywords: language teaching methods, psychology, schools of thought, Behaviorism

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Authors: Salah Al-Din I. Badran, Samad Ahmadi, Ismail Shahin

Abstract:

A blind source separation method is proposed; in this method, we use a non-uniform filter bank and a novel normalisation. This method provides a reduced computational complexity and increased convergence speed comparing to the full-band algorithm. Recently, adaptive sub-band scheme has been recommended to solve two problems: reduction of computational complexity and increase the convergence speed of the adaptive algorithm for correlated input signals. In this work, the reduction in computational complexity is achieved with the use of adaptive filters of orders less than the full-band adaptive filters, which operate at a sampling rate lower than the sampling rate of the input signal. The decomposed signals by analysis bank filter are less correlated in each subband than the input signal at full bandwidth, and can promote better rates of convergence.

Keywords: blind source separation, computational complexity, subband, convergence speed, mixture

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Authors: Hamid Khachab, Yamani Abdelkafi, Mouna Barhmi

Abstract:

The epitaxial growth has great important in the fabricate of the new semi-conductors devices and upgrading many factors, such as the quality of crystallization and efficiency with their deferent types and the most effective epitaxial technique is the molecular beam epitaxial. The MBE growth modeling allows to confirm the experiments results out by atomic beam and to analyze the microscopic phenomena. In of our work, we determined the growth processes specially the ZnSe epitaxial technique by Kinetic Monte Carlo method and we also give observations that are made in real time at the growth temperature using reflection high energy electron diffraction (RHEED) and photoemission current.

Keywords: molecular beam epitaxy, II-VI, morpholy, photoemission, RHEED, simulation, kinetic Monte Carlo, ZnSe

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Authors: Muhammad Faisal Khilji, Rana Shoaib Hamid

Abstract:

Subdural hematoma (SDH) is an extremely rare complication of immune thrombocytopenic purpura (ITP). We present a case of a 34 years old female who presented to the Emergency department of a tertiary care hospital with complaints of headache, on and off gums bleeding and upper respiratory tract symptoms for the last two weeks. Examination was unremarkable except some purpura over limbs. Investigations revealed zero platelets and peripheral film suggestive of ITP. Computerized tomography (CT) brain revealed bilateral SDH in the frontal areas extending into Falx cerebri. Impression of ITP with SDH was made. Patient was treated with intravenous immunoglobulin (IVIg), methyl prednisolone and initial Platelets transfusion. Patient recovered uneventfully with platelets reaching normal levels within a few days and resolution of SDH without surgery.

Keywords: headache, immune thrombocytopenia, purpura, subdural hematoma

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Authors: Laskri Yamina, Rehouma Abdel Hamid

Abstract:

In this paper we present a new class named polar of monic orthogonal polynomials with respect to the area measure supported on G, where G is a bounded simply-connected domain in the complex planeℂ. We analyze some open questions and discuss some ideas properties related to solving asymptotic behavior of polar Bergman polynomials over domains with corners and asymptotic behavior of modified Bergman polynomials by affine transforms in variable and polar modified Bergman polynomials by affine transforms in variable. We show that uniform asymptotic of Bergman polynomials over domains with corners and by Pritsker's theorem imply uniform asymptotic for all their derivatives.

Keywords: Bergman orthogonal polynomials, polar rthogonal polynomials, asymptotic behavior, Faber polynomials

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Authors: Abderrahmane Hemmani, Hamid Khachab, Dennai Benmoussa, Hassane Benslimane, Abderrachid Helmaoui

Abstract:

Back surface field GaAs with n -p-p+ structures are found to have better characteristics than the conventional solar cells. A theory, based on the transport of both minority carriers under the charge neutrality condition, has been developed in the present paper which explains behavior of the back surface field solar cells. That is reported with an efficiency of 25,05% (Jsc=33.5mA/cm2, Vco=0.87v and fill factor 86% under AM1.5 global conditions). We present the effect of technological parameters of the p+ layer on the conversion efficiency on the solar cell. Good agreement is achieved between our results and the simulation results given the variation of the equivalent recombination velocity to p+ layer as a function of BSF thickness and BSF doping.

Keywords: back surface field, GaAs, solar cell, technological parameters

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Authors: N. F. M. Mokhtar, N. Z. A. Hamid

Abstract:

This paper reports an analytical investigation of the stability and thermal convection in a horizontal anisotropic porous medium in the presence of Coriolis force and magnetic field. The Darcy model is used in the momentum equation and Boussinesq approximation is considered for the density variation of the porous medium. The upper and lower boundaries of the porous medium are assumed to be conducting to temperature perturbation and we used first order Chebyshev polynomial Tau method to solve the resulting eigenvalue problem. Analytical solution is obtained for the case of stationary convection. It is found that the porous layer system becomes unstable when the mechanical anisotropy parameter elevated and increasing the Coriolis force and magnetic field help to stabilize the anisotropy porous medium.

Keywords: anisotropic, Chebyshev tau method, Coriolis force, Magnetic field

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Authors: Hamid Vahidkia

Abstract:

The origins of the Universal Declaration of Human Rights (UDHR) are not widely understood, leading to misconceptions that need to be examined. Recent research disputes the idea that the UDHR was exclusively backed and endorsed by Western countries and even raised doubts about powerful nations backing the creation of global human rights norms. This article examines four political misconceptions regarding the Universal Declaration, with each one having some truth to it but also being misleading. The significance of small states in promoting human rights norms has been underestimated, just as the importance of large states has been exaggerated in history. The Universal Declaration was created through negotiations with the involvement of numerous states. All states have a stake in small states reclaiming their portion of history due to the legitimacy it gained from the political process that formed it.

Keywords: declaration. law, rights, humanity, UDHR

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Authors: Ahmad Sharif Ahmadi, Yoshitaka Kajita

Abstract:

Kabul city is experiencing urban land expansion in an unprecedented scale, especially since the last decade. With massive population expansion and fast economic development, urban land has increasingly expanded and encroached upon agriculture land during the urbanization history of the city. This paper evaluates the integrated urban land expansion impact on agriculture land in Kabul city since the formation of the basic structure of the city between 1962-1964. The paper studies the temporal and spatial characteristic of agriculture land and agriculture land loss in Kabul city using geographic information system (GIS) and remote sensing till 2008. Many temporal Landsat Thematic Mapper (TM) imageries were interpreted to detect the temporal and spatial characteristics of agriculture land loss. Different interval study periods, however, had vast difference in the agriculture land loss which is due to the urban land expansion trends in the city. the high number of Agriculture land adjacent to the city center and urban fringe have been converted into urban land during the study period in the city, as the agriculture land is highly correlated with the urban land.

Keywords: agriculture land, agriculture land loss, Kabul city, urban land expansion, urbanization

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Authors: Reza Fazaeli, Reza Eslami-Farsani, Hamid Targhagh

Abstract:

Low density polyethylene (LDPE) nanocomposites with 3, 5 and 7 wt. % cobalt ferrite (CoFe2O4) nanopowder fabricated with extrusion mixing and followed up by hot press to reach compact samples. The transmission/reflection measurements were carried out with a network analyzer in the frequency range of 8-12 GHz. By increasing the percent of CoFe2O4 nanopowder, reflection loss (S11) increases, while transferring loss (S21) decreases. Reflectivity (R) calculations made using S11 and S21. Increase in percent of CoFe2O4 nanopowder up to 7 wt. % in composite leaded to higher reflectivity amount, and revealed that increasing the percent of CoFe2O4 nanopowder up to 7 wt. % leads to further microwave absorption in 8-12 GHz range.

Keywords: nanocomposite, cobalt ferrite, low density polyethylene, microwave absorption

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Authors: Atefeh Ahmadi, Mohamed Sharif Mustaffa

Abstract:

Mental health problems that children introspect them are hardly identified. The internalizing nature of Anxiety Disorders as the most prevalent psychological diseases, make them been under recognized by parents and teachers and so become under attended by school counsellors and subsequently under referred to clinicians. The aim of this study is to investigate the level of Anxiety Disorders to clarify if it is necessary to run screening programs in rural educational settings. Spence children anxiety scale-malay-child for the first time in Malaysia distributed among 640 Malay rural primary school students aged from 9-11 years old. Cut-off score was considered one standard deviation more than the mean of all students’ scores. The results of descriptive analyses revealed the mean for scores of SCAS was 32.84 and 15.6% of students had high level of anxiety. In addition, the level and prevalence of six types of anxiety disorders based on SCAS were described. In regards to the study outcomes, screening for anxiety disorders in academic settings could prevent and reduce their side effects by early identification.

Keywords: anxiety disorders, primary schools, SCAS, screening

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Authors: Abdelkarim Ait Brik, Abdelaziz Khoukh, Mustapha Jammali, Hamid Chaikhy

Abstract:

The energy audit is the essential initial step to ensure a good definition of energy control actions. The in-depth study of the various energy-consuming equipments makes it possible to determine the actions and investments with best cost for the company. The analysis focuses on the energy consumption of production equipment and utilities (lighting, heating, air conditioning, ventilation, transport). Successful implementation of this approach requires, however, to take into account a number of prerequisites. This paper proposes a number of useful recommendations concerning the energy audit in order to achieve better results, and a case study concerning the lighting audit of a Moroccan company by showing the gains that can be made through this audit.

Keywords: energy audit, energy diagnosis, consumption, electricity, energy efficiency, lighting audit

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Authors: Hassan Athari, Alireza Ruhi Sales, Amin Pourafshar, Seyyed Mehdi Pestei, Marc. A. Rosen

Abstract:

In order to achieve high efficiency and high specific work with lower emissions, the use of advanced gas turbine cycles for power generation is useful and advantageous. Here, evaporative inlet air cooling is analyzed thermodynamically in the form of air film blade cooling of gas turbines. As the ambient temperature increases during summer months, the performance of gas turbines particularly the output power and energy efficiency are significantly decreased. The utilization of evaporative inlet cooling in gas turbine cycles increases gas turbine performance, which can assist to solve the problem in meeting the increasing demands for electrical power and offsetting shortages during peak load times. In the present research, because of the importance of turbine blade cooling, the turbine is investigated with cold compressed air used for cooling the turbine blades. The investigation of the basic and modified cycles shows that, by adding an evaporative cooler to a simple gas turbine cycle, for a turbine inlet temperature of 1400 °C, an ambient temperature of 45 °C and a relative humidity of 15%, the specific work can reach 331 (kJ/kg air), while the maximum specific work of a simple cycle for the same conditions is 273.7 (kJ/kg air). The exergy results reveal that the highest exergy destruction occurs in the combustion chamber, where the large temperature differences and highly exothermic chemical reactions are the main sources of the irreversibility.

Keywords: energy, exergy, wet compression, air-film cooling blade, gas turbine

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