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Search Results: 1 - 10 of 735 matches for " Arash Mirabzadeh "
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Preterm Delivery and Psycho–Social Determinants of Health Based on World Health Organization Model in Iran: A Narrative Review
Mahrokh Dolatian,Arash Mirabzadeh,Ameneh Setareh Forouzan,Homeira Sajjadi
Global Journal of Health Science , 2012, DOI: 10.5539/gjhs.v5n1p52
Abstract: Background: Preterm delivery is still the primary cause of mortality and morbidity in infants, which shows a problematic condition in the care of pregnant women all over the world. This review study describes prevalence and psycho - socio-demographic as well as obstetrical risk factors related to live preterm delivery (PTD) in the recent decade in Iran. Methods: A narrative review was performed in Persian and international databases including PubMed, SID, Google Scholar, Iran Medex, Magiran and Irandoc from 2001 to 2010 with following keywords: preterm delivery and pregnancy outcomes with (prevalence, socioeconomic condition, structural determinant, Intermediary determinants, Psychosocial factor, Behavioral factor and Maternal circumstance, Health system) All of article was reviewed then categorized based on WHO model. Results: Totally 52 article were reviewed and 35 articles were selected, of which 26 were cross-sectional or longitudinal, 9 were analytical (cohort or case-control). The prevalence rates of preterm delivery in different cities of Iran were reported between 5.6% in Quom to 39.4% in Kerman. The most common social factors in structural determinant were educational level of mother, and in intermediary determinants were Psychosocial factor (maternal anxiety and stress during pregnancy), Behavioral factor and Maternal circumstance (violation and trauma) and in Health system, lack of prenatal care. Conclusion: The prevalence rate of preterm delivery is a matter of concern. Since many psycho-social factors may affect on the condition and its high rate in poor communities might reveals a causal relationship among biological and psychosocial factors, performing etiological investigations is recommended.
Evaluation of Prevalence and Effective Factors on Changing the Diagnosis from Mood Disorders to Schizophrenia after Six Years
Arash Mirabzadeh,Parisa Pakdel,Katayoun Khoushabi,Mohammad Reza Khodaei
Iranian Journal of Psychiatry , 2008,
Abstract: "n "nObjective: The purpose of this study was to assess the prevalence and possible variables on changing the diagnosis of mood disorder patients to schizophrenia. "n Method: "n "nThis study was a retrospective and comparative analytic research that was performed in 2006 in Razi psychiatric hospital. The sample consisted of all the 176 patients who were hospitalized in 2000 with the diagnosis of mood disorder. The patients were divided into two subgroups: the stable group with a persistent mood disorder diagnosis and the changed group with a changed mood disorder diagnosis to schizophrenia. Data were analyzed between these groups using chi-square and t student test. "nResults: Findings showed that 31.3% of all the patients shifted towards chizophrenia; 23.3% and 32.9% of the patients with major depressive disorder and bipolar disorders shifted towards schizophrenia respectively. No statistical difference was observed between the groups in demographic variables but there was a statistical difference in some of the clinical variables such as psychotic features (p<0.01), severe clinical features (p<0.05), and the gradual onset of disorder (p<0.05) with changing the diagnosis to schizophrenia. "nConclusion: Recognition of clinical variables associated with changing the diagnosis to schizophrenia such as psychotic features, severe clinical features and the gradual onset of disorder will help clinicians to manage these patients better than the past.
An Ultra Low-Voltage and Low-Power OTA Using Bulk-Input Technique and Its Application in Active-RC Filters  [PDF]
Arash Ahmadpour
Circuits and Systems (CS) , 2011, DOI: 10.4236/cs.2011.23026
Abstract: This paper presents the design of a two-stage bulk-input pseudo-differential operational transconductance amplifier (OTA) and its application in active-RC filters. The OTA was designed in 90 nm CMOS process and operates at a single supply voltage of 0.5 V. Using a two-path bulk-driven OTA by the combination of two different amplifiers the DC gain and speed of the OTA is increased. Rail-to-rail input is made possible using the transistor’s bulk terminal as in input. Also a Miller-Feed-forward (MFF) compensation is utilized which is improved the gain bandwidth (GBW) and phase margin of the OTA. In addition, a new merged cross-coupled self-cascode pair is used that can provide higher gain. Also, a novel cost-effective bulk-input common-mode feedback (CMFB) circuit has been designed. Simplicity and ability of using this new merged CMFB circuit is superior compared with state-of-the-art CMFBs. The OTA has a 70.2 dB DC gain, a 2.5 MHz GBW and a 70.8o phase margin for a 20 PF capacitive load whereas consumes only 25 µw. Finally, an 8th order Butterworth active Biquadrate RC filter has been designed and this OTA was checked by a typical switched-capacitor (SC) integrator with a 1 MHz clock-frequency.
Investigation of Phosphorous Leaching to Soil Depth by Irrigation with Raw and Treated Domestic Wastewater Obtained from Ekbatan Treatment Plant
A. Hassanoghli,A. Liaghat,M. Mirabzadeh
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: Increased chemical compounds in soil are the most important results of irrigation with domestic wastewater and treated effluents which contain some nutrients such as phosphorous (P). This process could increase the soil fertility, leading to the decrease of chemical nutrient consumption and consequently the cost of agricultural production. A research project was carried out in Tehran region for two years in order to investigate the capabilities of soil and plant in absorption and storage of wastewater contaminants, namely, phosphorous, and also the transmission of them to drain depth as a result of irrigation practice. To do the research, a series of lysimeters based on a statistical factorial experiment in the form of randomized complete design (3x3x3) were used. Raw and treated domestic wastewater, obtained from Ekbatan Housing Complex, and well water (control) were used to irrigate raw edible vegetables including parsley, carrot and tomato. The results showed that the amount of phosphorous leaching through soil to drain depth was between 0.90% and 3.56%, and between 1.03% and 4.15% of the phosphorous concentration in raw wastewater and treated one entered into the soil, respectively. Also, mass balance analyses showed the average phosphorous reduction ranged from 97.2% to 99.9% of the phosphorous entered with wastewater. During two years of study, the maximum concentration of PO4 measured in drained water was about 0.21 mg/L obtained from lysimeters irrigated with raw wastewater. This was much lower than the permissible PO4 amount for discharging the effluents to the surface water resources (6 mg/L PO4 is permitted by Iranian Environmental Protection Organization).
Proposing a New Metric for Collaborative Filtering  [PDF]
Arash Bahrehmand, Reza Rafeh
Journal of Software Engineering and Applications (JSEA) , 2011, DOI: 10.4236/jsea.2011.47047
Abstract: The aim of a recommender system is filtering the enormous quantity of information to obtain useful information based on the user’s interest. Collaborative filtering is a technique which improves the efficiency of recommendation systems by considering the similarity between users. The similarity is based on the given rating to data by similar users. However, user’s interest may change over time. In this paper we propose an adaptive metric which considers the time in measuring the similarity of users. The experimental results show that our approach is more accurate than the traditional collaborative filtering algorithm.
An Enhanced Bulk-Driven Folded-Cascode Amplifier in 0.18 µm CMOS Technology  [PDF]
Arash Ahmadpour, Pooya Torkzadeh
Circuits and Systems (CS) , 2012, DOI: 10.4236/cs.2012.32025
Abstract: A new configuration of Bulk-Driven Folded-Cascode (BDFC) amplifier is presented in this paper. Due to this modifying, significant improvement in differential DC-Gain (more than 11 dB) is achieved in compare to the conventional structure. Settling behavior of proposed amplifier is also improved and accuracy more than 8 bit for 500 mV voltage swing is obtained. Simulation results using HSPICE Environment are included which validate the theoretical analysis. The amplifier is designed using standard 0.18 μm CMOS triple-well (level 49) process with supply voltage of 1.2 V. The correct functionality of this configuration is verified from –50℃ to 100℃.
Power Quality Consideration for Off-Grid Renewable Energy Systems  [PDF]
Mojgan Hojabri, Arash Toudeshki
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.55039
Abstract:

Necessity of electricity access in remote area is the main reason for expanding decentralized energy system such as stand-alone power systems. The best electrical power supply must provide a constant magnitude and frequency voltage. Therefore, good power quality is an important factor for the reliable operation of electrical loads in a power system. However, the current drawn by most of electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, especially in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide often struggle with system failures and equipment damage due to poor power quality. In this paper, MAT- LAB/Simulink is used to model and analyses power quality in an off-grid renewable energy system. The results show high voltage transient when the inductive loads were switched OFF. The voltage and current harmonics are also determined and compared for various types of loads.

Elevated Ferrite Film Circulator with Different Permittivities for Layers: An Analytical Expression for the Input Conductance Employing Perturbation Method  [PDF]
Arash Rashidi, Ali Banai
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.29069
Abstract: The main idea of this paper is to find an analytical formula for the input conductance of an elevated ferrite film circu-lator to match it systematically to the desired matching network. For solving the ferrite loaded dielectric resonator included in stripline elevated ferrite film circulator, the off diagonal components of the permeability tensor are taken as the perturbation. The electromagnetic fields computations are done for unperturbed structure. The dipolar resonant frequencies corresponding to harmonics of the resonant modes are then calculated using the perturbation integrals. The quality factor of the circulator is derived in terms of these dipolar resonant frequencies. Energy integrals are calculated to find the energy stored in the ferrite and dielectic layers. An analytical expression for the input conductance of the elevated ferrite film circulators is derived by using the quality factor and energy integrals. In this expression the ferrite and dielectric layers can have different permittivities. Some discussions about the effect of ferrite film thickness and permittivity mismatch on the bandwidth of the circulator are investigated by HFSS commercial software.
Hydrological Analysis and Ability Assessing of Flood Gating of Karaj Watershed According to the Form of the Watershed  [PDF]
Arash Talari, Roya Gholizadeh
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.66029
Abstract: The numeral trait of aquiferous zones in flowage studies and estimations is under most parts of nation. In this study Karaj aquiferous zone in Alborz province was surveyed from the view point of form, the agglomeration of drainage net length of channel and space. The orientation of hillside was specified as the affective factor on creating and streaming the flowage. A flow aggregating hydrological model for the studied zone was prepared and amount of the flow is mostly in which parts of the zone the delay and centralization time in the zone was evaluated and the related diagrams were derived. Finally, the zone was divided into 4 main subzones and their drainage nets were ranked and by 4 factors namely, space, length of canal, drainage aggregation and branch ratio affecting on performance of the zone from the view of from and appearance was surveyed. The factors interfering in SPSS software and their correlations were specified and specific coefficients stand in their related charts. By considering in the zone width and charts it is specified which of the sub zones has the most flowage potential from the view of the zones physical and numeral qualifications. All plots were prepared using GIS and WMS software and the studied zone’s hydrograph was depicted.
Investigation and Comparison of the DIBL Parameter and Thermal Effects of SOD Transistors and SOI Transistors and Improving Them with the Change of Their BOX Thicknesses  [PDF]
Nooshien Laderian, Arash Daghighi
Journal of Electronics Cooling and Thermal Control (JECTC) , 2018, DOI: 10.4236/jectc.2018.82002
Abstract: In this paper, thermal effects and Drain Induced barrier lowering (DIBL) of silicon-on-insulator (SOI) and silicon-on-diamond (SOD) transistors with 22 nm channel lengths using hydrodynamic simulations have been investigated. Thermal conductivity of diamond in contrast to thermal conductivity of silicon dioxide is significantly higher. Hence, the heat transfers faster in silicon-on-diamond transistors. Lattice temperature of SODs is lower than that of similar SOIs. By using SODs in Integrated circuits with the first transistor turning on and active, neighboring transistors will have the same level of heat as the active transistor. As a result, the DIBL factor will be increased; this is an undesired phenomenon in CMOS applications. To resolve this issue, we propose a new method which is the thickness reduction of buried diamond layers inside of transistors. Due to this change, DIBL of active transistor will be improved, the exceeding lattice heat of side transistors will be evacuated through the devices and their temperatures will be deduced in large scale.
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