Showing 20 results for Dalir
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
In the Persian language, which follows the SOV (Subject-Object-Verb) word order, the interrogative complement or prepositional object usually appears after the object in the focal position. However, it is possible to move this phrase to other positions within the sentence. The aim of this study is to investigate the processing of interrogative complement displacement in Persian using Event-Related Potentials (ERPs) based on Friederici's syntactic processing model. This study focuses on the central-parietal region of the brain, specifically the N400 and P600 components, which, according to Friederici's language processing model (1995), examine the filler-gap dependency structure and the mental representation of these phrases. Four different positions of the interrogative complement in Persian were examined, and 50 sentences were constructed for each condition.. The results indicate that the displacement of the interrogative complement leads to different brain responses, with an increase in N400 amplitude in the central-parietal region when the interrogative complement follows the subject, and an increase in P600 amplitude in the initial or focal position of the interrogative complement. These findings suggest that the displacement of the wh-complement in Persian, according to Friederici's model, has a neurophysiological basis and may represent a filler-gap dependency structure in mental representation.
Volume 2, Issue 1 (Issue 1 (Tome 2)- 2012)
Abstract
Nowadays the urban growth pattern of cities is growing dramatically; and current suburbs of cities will form the inseparable components of the main city in the near future. In all cities of world vertical and horizontal urban growth have been one of the most important factors noticed by urban managers and planners. Urban growth is a spatial - structural process that refers to the increased importance of towns and cities as a concentration of population within a particular economy and society. Increase in urban points as quantitative issue shows itself in the forms of increase in population of cities and development in built up area scale. The unorganized physical growth of cities is due to their physical discrete and separate development which is mostly in form of forming individual and separate parts. Hence, analysis of the current physical status, and prediction of the future development of cities due to its influence on the politics and management of city and human resources, is of great importance. Regarding the numerous factors affecting the inharmonic physical urban growth, the present article has investigated the rate of urban horizontal growth from two aspects of area and direction.The research method in this article is analytical- comparative and with respect to the evolution of the physical- spatial pattern of Tabriz metropolitan in the 1956-2006 period. Shannon’s Entropy model is utilized for evaluation of the rate of the urban horizontal growth diversity. In order to use this model first we draw the complete and detailed plan of Tabriz city in concentric buffers with width of one kilometer between years 1956-2006 using Auto Cad software and the physical gravity center of Tabriz city which is the same center of cultural- historical part has been considered as basis for buffering modulation, and Sectoral- Geographical model is used for specification of urban growth directions. . In the next phase center of city gravity has drawn in the form of circle with determined diameter and the center of this circle was considered as basis for modulation of geographical sectors and sectoral buffering in 12 geographic directions. The attained results of analyzing the research findings has shown that the sprawl growth and diversity of inharmonic development has occurred in Tabriz metropolitan. The maximum of this rate has happened on the year 1996 and directions of horizontal urban growth are completely coincided on the margins of main connection corridors of city.
Volume 3, Issue 1 (8-2011)
Abstract
This article tries to analyze the reasons and mechanism of the society’s effect on individual based on role theories. These theories believe that occupation of different positions by individuals is accompanied by specific expectations. An individual has two definite paths encountering the present expectations: to accept or not to accept followed by punishment and rejection. To desert from punishment, individuals always choose the first path that means to submit the social will. But social dominance over individuals through positions is not limited to the first path. Rather the society by allowing structural opportunities (rights, privileges, chances and role conditions), which are different for any position, dominates on individuals behavior and its qualities. It makes to establish in distinct ways. Role conflicts and type and quality of individual relations in positional sets have also the same results.
Volume 4, Issue 1 (10-2012)
Abstract
Before the Islamic Revolution in Iran, different groups and parties strived to overthrow the Pahlavi regime. To realign the people and elites in the society with them, they had to present their rationale behind thetheircertainaty about rom he objective conditions. Regime, however, rejection of the existing regime and the desirable condition following that as well as to show the way to achieve that promised society. Each active group or party at the time drew on their contemporary schools and theories for offering the reason of the rejection of the existent condition and the way to achieve the ideal one. Among them were some parties, who put their analysis of the socio-political conditions on the basis of Marxist ideology or campaigned against the Pahlavi regime building on this ideology. Such parties included the Tudeh Party, FadaeeKhalgh guerrillas and Mujahedeen-e-Khalgh guerrillas. The Tudeh Party labeled this regime as totalitarian and based on the American imperialism. Consequently, it requested the replacement of this regime with a national one. This party regarded revolution as the best way to overthrow the regime; however, they believed that preparing the population’s mentality for revolution required political and cultural actions. The Fadaee guerrillas used this same argument against the Pahlavi regime but they believed that the alternative government must be established under the leadership of a leading Labor Party. The Fadaee guerrillas too saw revolution as the only way to the ideal condition but, unlike the Tudeh Party, they believed in guerrilla war as a way to prepare the people. The Mujahedeen-e-Khalgh developed the same argument to oppose the Pahlavi regime but, unlike the two other they regarded the mindset as already prepared for revolution apart from their certainty about the objective conditions. According to the Mujahedeen organization, the only reason behind the defeat of the campaign was lack of organization to lead the populations, a vacuum that must be filled by the parties. For Mujahedeen, the ideal society was a classless and monotheist one.
Volume 7, Issue 4 (1-2008)
Abstract
Monetary and fiscal policies are the main macroeconomic instruments, so the most important step in programming for national development is to know how they affect economic variables. On the other side, agricultural sector is the main sector in economic growth and development and a strategic sector for supplying food for growing population, so this sector has a great importance in development programs. In this research, the effect of monetary and fiscal policies on the major factors of agricultural sector in Iran i.e. added value, price, and export are investigated by using Vector Auto-regressive Model (VAR). Results show that monetary and fiscal policies have positive effect on added value, price and export in agricultural sector but negative effect on investment in this sector. Furthermore, short-run effect of monetary policies on added value, export and investment is more than that of fiscal policies but long-run effect of fiscal policies on the added value, export and investment in agricultural sector is more than that of monetary policies. Furthermore, a one-S.D. liquidity innovation has a positive decreasing effect on the added value and price in agriculture sector but its effect on investment is positive in the first year and will be nearly consistent in the next years. In addition to that the effect on the export is positive in the first year and negative in the next years. Each government budget innovation has a positive effect on added value, export and price in agriculture sector but its effect on investment is positive in the first year and negative in the next years.
Volume 13, Issue 2 (3-2022)
Abstract
Numerous concepts have been created to justify governance. The system of knowledge-power, often produced by religious scholars, has sought to define and establish governance in accordance with historical contexts in relation to the Almighty God. The concept of the shadow of God (Zellul-lah) is one of these concepts that has been defined and used for the rulers in the form of a system of beliefs. This notion is often considered in conjunction with the notions of legitimacy, such as Farreh Izadi, as being a synonym in a sense, while its semantic discrepancies in the historical context has been ignored. Therefore, this study seeks to answer the question of how the philosophy of the notion of Zellul-lahi in the era of Nader Shah was defined in the system of knowledge-power inter-relationship, and its functionality. Using the theoretical discussions of Foucault's “knowledge-power” method, as well as the "history of concept" approach, this research will explain the theory of Zellul-lahi in the era of Nader Shah and its consequences. The results of this study show that in the Nader shah era, there was a breakup in the “knowledge-power” system. This is true by taking into consideration that official-historians as producers of knowledge tried to define a different position for it due to Nader Shah’s separation from the legitimizing system of the Safavid era. For this reason, the concept of Zullul-lah in this age, as an independent approach, and in direct connection with God in the system of knowledge and power, has been established and exclusively used for Nader. This new system of knowledge-power, which was formed in this era, later led to a great change in the history of Iran, and helped in the evolution of the socio-political order of our country.
Volume 13, Issue 3 (10-2024)
Abstract
The survey of the fish assemblage in the planned place to establish artificial reefs in the western and eastern bays of Jask was carried out in the winter and spring of 2024. Sampling was done by Gillnet and Trap methods in 4 stations located in the western bay and eastern bay of Jask at a depth of 10 to 30 meters. 68 aquatic species (60 fishes, 5 crabs, 2 oysters, and 1 shrimp) were sampled and recorded. Of these, Nemipterus japonicus (32.6 %) was the most abundant, Saurida tumbil (12.6 %), Anodontostoma chacunda (12.5 %), Ilisha megaloptera (9.8 %), Scomberoides tol (6.4 %), Sphyraena putnamae (4.1 %), Lactarius lactarius (2.6 %), Muraenesox bagio (2 %), Pomadasys kaakan (1.9 %), Otolithes ruber (1.6 %) located in the next rank. The average catch per unit of effort of gillnet was 45±10.2 kg/piece×hour and for Trap 7.3±4.2 kg/trap×day. In this research, it was found that the population of species related to artificial reefs, such as Epinephelus coioides , Lutjanus johnii , and Lethrinus nebulosus were relatively low, and mainly below the maturity size, it seems that the stocks of this group of fish need to be enhanced. Therefore, it is recommended to consider the target species in the design of the structure and arrangement of the artificial reefs, on the other hand, the shelter and protective aspects of the artificial reefs for the reef-dependent juvenile also be considered. |
Volume 13, Issue 4 (12-2013)
Abstract
The main aspect of this research study is investigation on scour phenomenon around marine pipelines with respect to submerged impermeable plates beneath the pipe. So far, numerous investigations have been done but the main difference of this study with them is installation an impermeable base plate under the pipelines. Installing these impermeable plates mainly causes that the developed streamlines under the bed, located under the pipeline, are lengthened and accordingly the pressure gradient reduces across the pipe. Reduction of the pressure gradient may be considered an important issue since one of the most important criteria of establishing and progressing of scour under pipelines is the formation of piping phenomenon under the pipelines. This phenomenon is due to dominance of the pressure gradient on floating weight of the bed materials. For this research study, firstly scour phenomena under the pipelines were investigated both for unprotected pipelines and protected pipelines with submerged impermeable plates, with the piping phenomenon under the pipelines were being considered for both cases. The experiments were carried out in a channel with 10m length, 0.25m width and 0.5m depth. P.V.C. pipes with four diameters (i.e., 2cm, 3cm, 4cm and 5cm) and 0.5cm thickness were investigated. The bed materials were consisted of sediment particles with median size of 0.50 mm and geometric standard deviation of 1.43. The specific gravity of bed materials was 2.65. All experiments were run at clear water conditions. For each test the steady approach flow was adjusted so that the ratio of velocity to critical velocity was equal to about 0.85 on the centerline of the flume. A number of rectangular galvanized iron plates with 25cm in length, 0.7mm thickness and various dimensions of breadths were selected as countermeasure tools for scouring phenomenon. Then, the scour depth beneath two parallel pipelines with side by side arrangements and their interaction on scouring process were investigated. Finally, with installing impermeable base plates under the pipelines, the effect of these plates on scour phenomenon were studied for any arrangements of the parallel pipelines. The experimental results showed that installation a plate under the pipeline could prevent the formation of scour hole to some degrees and protect them from scour hazards. For all test cases of unprotected pipelines, the maximum dimensionless scour depth beneath the pipelines decreased when the pipe diameter increased. For side by side arrangement of two parallel pipelines, the formed scour depth decreased when the distance of pipelines increased. Then, for practical purposes, in order to reduce the maximum scour depth it is recommended that the distance of two parallel pipelines increases as far as possible or a submerged base plate may be used beneath the under pipeline. For all test cases of pipelines with impermeable base plates, the scour process will not further occur unless due to wake vortices
Volume 13, Issue 4 (1-2011)
Abstract
Objective: Survey of molecular characterization of nucleoprotein gene of H9N2 avian influenza viruses and determination of the genetic relationship of Iranian H9N2 viruses and other Asian viruses.
Materials and Methods: The nucleoprotein (NP) genes from 4 isolates of H9N2 viruses isolated from commercial chickens in Iran during 2008-2009 were amplified by RT-PCR method and sequenced. Nucleotide sequences (orf) of the NP genes were used for phylogenetic tree construction.
Results: Nucleotide sequence analysis of the NP gene showed that the Iranian virus isolates did not exhibit insertions or deletions within nucleoprotein (NP) gene as compare with their prototype A/turkey/winconsin/66; however numerous point mutations were occurred in the gene length of these viruses similar to the previous Iranian strains. Nucleotide sequence analysis showed that these isolates are very closely related (96/7-99/6) and shared a homology of 91/9-92/3% and 91/5-92% with 2 human isolates A/HK/1073/99 and A/Hk/2108/2003, respectively. Phylogenetic analysis of the NP gene showed that all the NP genes of the Iranian H9N2 viruses fall into a single group within a G1-like sublineage which had contributed as donor of six internal genes to H5N1 a highly pathogenic avian influenza.
Conclusions: The current study indicated that the NP gene of H9N2 influenza viruses circulating in Iran during the past years were well conserved. It seems that the differences between these Iranian virus isolates are the result of accumulation of point mutations among them.
Volume 15, Issue 2 (summer 2015 2015)
Abstract
Historically, the mankind has benefited from social capital in his collective life course implicitly and unconsciously. Nowadays, the concept of social capital has been included in the center of economy and community. The communities need to identify the framework of social capital and its consequences in order to overcome recession and deterioration. The relationship among socioeconomic indicators and social capital is one of the most important effects and interactions of social capital. In this article we try to identify the interaction between social capital and human development in the provinces of Iran. To do this, we use vector autoregressive panel data for the period 2000-2009. The results show that social capital has a positive effect on human development in the Iran’s provinces. On the other side, human development will generate social capital strata in the country.
Volume 16, Issue 4 (1-2016)
Abstract
Abstract:
Modern horseshoe spillways are combination of external and internal weirs and determination of hydraulic parameters of this kind of spillways is essential. In this study, by making physical models of Modern horseshoe spillway in laboratory dimension, some hydraulic parameters of modern horseshoe spillways like discharge coefficient, discharge rate through the two weirs and water surface profiles in different parts of horseshoe weir are investigated. The results showed that by increasing the ratio of head (h) to external weir’s Length (Lw) for Lw≤100 cm, the discharge coefficient for internal weir (CO) increases linearly. By increasing ratio of internal weir discharge to external weir discharge Q1/Q2, the discharge coefficient has a decreasing trend between 0.65 to 0.3 . By increasing the external weir length, the discharge rate through external weir increases while it decreases in internal weir. The external weir with Lw=100 cm has better performance than other Lws and If we select it as the better length, on average 31 percent of the flow will pass from the internal weir. Classic and Modern horseshoe spillways are able to reduce the head above the weir respectively to 28 and 50% in comparison to rectangular weir head with the same width. Investigation of the water surface profiles shows that by creating an internal weir, rooster tail hydraulic jump that existed in Classic horseshoe spillway is removed.
Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.
Abstract:
Modern horseshoe spillways are combination of external and internal weirs and determination of hydraulic parameters of this kind of spillways is essential. In this study, by making physical models of Modern horseshoe spillway in laboratory dimension, some hydraulic parameters of modern horseshoe spillways like discharge coefficient, discharge rate through the two weirs and water surface profiles in different parts of horseshoe weir are investigated. The results showed that by increasing the ratio of head (h) to external weir’s Length (Lw) for Lw≤100 cm, the discharge coefficient for internal weir (CO) increases linearly. By increasing ratio of internal weir discharge to external weir discharge Q1/Q2, the discharge coefficient has a decreasing trend between 0.65 to 0.3 . By increasing the external weir length, the discharge rate through external weir increases while it decreases in internal weir. The external weir with Lw=100 cm is the optimum length and If we select it as the optimum length, on average 31 percent of the flow will pass from the internal weir. Classic and Modern horseshoe spillways are able to reduce the head above the weir respectively to 28 and 50% in comparison to rectangular weir head with the same width. Investigation of the water surface profiles shows that by creating an internal weir, rooster tail hydraulic jump that existed in Classic horseshoe spillway is removed.
Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.
Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.Keywords: Modern & Classic horseshoe spillway, Discharge coefficient, Internal weir, Physical model.
Volume 18, Issue 4 (winter 2018 2018)
Abstract
In recent years, declining fertility rate has been main problem in Iran. The theoretical framework shows that economic and social variables affect fertility rate. Household expected income is one of the most important variables influencing fertility rate. Expected income is directly related to the quality and quantity of future parents’ jobs. Using a panel data model, this research investigates the effect of labor market uncertainty on fertility rate in Iran's provinces during 2005-2013. Since there is no single index for labor market uncertainty, a proxy for job uncertainty was calculated for women and men. According to research findings, job uncertainty in both women and men is of important influence on fertility rate. Men's job uncertainty has a positive effect, but women's job uncertainty has a negative effect on fertility rate. As a result, the structure and expectations of the labor market among men and women are crucial factors in determining fertility rate. Hence, policymakers can increase fertility rates by improving the labor market structure
Volume 19, Issue 1 (7-2015)
Abstract
Many companies are dependent on purchasing the required professional services (such as managerial, marketing, accounting, legal, and IT services) from specialist contractors. The contract between such contractors and clients forms an agency relationship, so the agency theory may be used to regulate the relationship between them. However, since the abstract knowledge is the subject of exchange between the client and professional service provider and there is a knowledge asymmetry between these two parties, the application of agency theory as it is used for traditional owner-manager agency relationship is not possible for principal-professional agent relations. In this article, we expand the agency theory to be applicable in such agency relationships. We suggest that a combination of behavior-based and outcome-based contracts be employed in principal-professional agent relationships, if possible. Moreover, we discuss why it is very hard or even impossible to have a direct control over professional service contractor and to measure the outcomes of its services. We finally propose two alternative mechanisms (1-trust and self-control, and 2-indirect control) for reducing opportunistic behaviors and solving some agency problems occurring in principal-professional agent relations.
M. Dalir, N. Bigdeli,
Volume 20, Issue 7 (July 2020)
Abstract
Today, the magnetic levitation system is widely used in various industries. This system is inherently unstable and nonlinear, which is presented by nonlinear equations. On the other hand, the existence of a time delay in these systems also causes system instability or even chaos, which creates additional problems in their control, thus requiring the design of robust and optimal control. In this paper, a robust adaptive intelligent controller based on the backstepping-sliding mode is proposed for the stability and proper tracking of the magnetic levitation system in the presence of time delay, uncertainty, and external disturbances. Due to changes in the equilibrium point, comparative control is used to update the system's momentary information and intelligent controller to estimate uncertainties and disturbances and non-linearity of the system. A robust controller is used to asymptomatic stabilize the Maglev system. The Lyapunov stability theory is used to analyze the stability of the magnetic levitation system with the proposed controller. In the end, in order to demonstrate the performance of the proposed controller, numerical simulations have been used in MATLAB software. The simulation results show that good tracking has been performed and the controller is very good against noise and disturbance.
Volume 20, Issue 137 (July 2023)
Abstract
Frankincense is a resinous gum obtained from some species of the Boswellia genus. The use of frankincense for food and medicinal uses dates back to more than five thousand years ago, but despite its importance and application, only 27-35% of it is soluble in water. As most frankincense gum is insoluble, this research used the response surface method to study the effect of different chemical modification conditions (NaOH concentrations (X1), reaction temperatures (X2), and MCA concentrations (X3)) on increasing the solubility percentage. The results of the optimization process of the chemical modification of frankincense gum indicate that the conditions of maximum solubility are equal to 85.49, with a desirability rate of 0.97. Therefore, the concentration of NaOH and MCA equal to 0.048, 0.01 mol, and a temperature of 75 degrees Celsius chose as the best optimization conditions. In addition, the intrinsic viscosity and molecular weight of the native gum were higher than the modified gum under optimal conditions. There is a significant difference between the apparent viscosity of natural gum (18.02 ± 0.726 mPa.s) and modified (17.36 ± 0.681 mPa.s) (p>0.05). The results indicate that native and modified gum in optimal conditions show a shear thinning behavior with increasing shear rate, and their behavior is similar to pseudoplastic. The colorimetric test with image J software indicated that carboxymethylation of frankincense gum led to significant changes (P < 0.05) in the total color difference factor (ΔE) and whiteness index (WI), L*, a*, and b*factor.
Volume 21, Issue 2 (summer 2021 2021)
Abstract
The economic structure in oil-dependent countries is different from other countries. The human development index (HDI) may increase due to rising oil rents and subsequent increases in per capita income, but there may be no significant improvement in other indicators (literacy rate and life expectancy). The improper injection of oil rents into the country's budget without investing in manufacturing, agriculture and services, whether domestically or abroad, leads to the Dutch disease and “resource curse”. Bilateral official development assistance (BODA) from the members of the Development Assistance Committee (DAC) of the Organization for Economic Cooperation and Development (OECD) can have a positive impact on human development without having a negative impact on various economic and social aspects. In this regard, this study examines the impact of BODA on human development using a Panel-Fully Modified Ordinary Least Squares (Panal-FMOLS) model in selected countries (Iran, Iraq, Turkey, Yemen, Jordan, Azerbaijan and Georgia from Southwest Asia, and Indonesia, Philippines, Malaysia, Thailand, Vietnam and Myanmar from Southeast Asia) during 1999-2018. The results indicate that BODA and health expenditure have positive and significant effects on HDI. The findings also indicate a significant negative impact of oil rent, population growth rate and unemployment rate on HDI. The effect of personal remittances is different in the two samples, so that these funds have negative impact on HDI in the Southwest Asia and a positive effect on HDI in the Southeast Asia.
Volume 21, Issue 4 (winter 2021 2021)
Abstract
Establishing industrial free trade zones is one of the strategies of developing countries to take advantage of global trade, without the disadvantages of free trade expanding to the country. To take advantage of the free trade zones, Iran has so far established seven zones in different regions. But one of the important questions after the establishment of free trade zones is whether the established free industrial trade zones are able to improve economic growth and development. In this study, using the Synthetic Control Approach, the answer to the mentioned question is given for the Anzali Free Zone. In other words, the effect of establishing the Anzali free zone on the growth and development of Guilan province is estimated. The results of the study show that the Anzali Free Zone has not been able to have a positive and significant effect on the growth and development of Guilan province. Of the four variables under study, the establishment of the Anzali Free Zone has negative effect on the per capita industrial value-added in Guilan province compared to the control group. Also, it has not have significant effect on the amount of agricultural value-added, services value-added, the real GDP per capita in Guilan province compared to the control group.
Therefore, it can be concluded that the establishment of the Anzali Free Zone has not been able to achieve one of its main goals, which is the development and growth of the Guilan.
Volume 23, Issue 2 (Summer 2019)
Abstract
Introduction
Global warming and climate change are nowadays significant challenges for humankind. It is widely and generally accepted that the increase of greenhouse gases emissions (GHGs) in the atmosphere are caused by anthropogenic effects especially in modernized and industrialized countries. Consequently, cleaner energy generation is needed in order to reduce global GHGs emissions (Waewsak et al., 2014). Wind energy becomes today a promising option to complement the conventional energy source, especially in region where the existing power plants are not sufficient to match the increasing electricity demand. This success is principally due the rapid growth of the wind technology which led the wind power to be more competitive by reducing the cost of electricity produced (Djamai and Merzouk, 2011). Since there has no comprehensive wind potential study in Kermanshah province, it is necessary to pay this important subject to reply for increased demand of electricity. Thus this paper aimed to assess economical usage of wind power in Kermanshah province.
Methodology
In this study we assessed economic feasibility of wind energy usage at 13 sites in Kermanshah province. In order to carry out the research, 3-hour wind speed data in 2009 to 2013, topography, land cover and obstacle maps were used, and ten models of wind turbines with different rated power were investigated. It has been calculated Capacity Factor, Operating Probability of wind turbines, and Annual Energy Production for selected turbines in 0.03m surface roughness using WAsP and Windographer software. Economical evaluation was down by Net Present value method and benefit costs analysis (B/C) in 13 sits and 10 models of wind turbines. Also in this research it was used Extra Investment Analysis (EIA) method to choose the best project from the initial Selected Projects. After investigation of cost analysis, it was determined the most economical wind turbine and site for utilization wind energy in Kermanshah province.
Results and discussion
The maximum Capacity Factor of selected turbines has calculated in Gilanqarb (46.4%), Tazeabad (44.2%) and Somar (39.2%). This is because of different wind climatology of these sites in comparison with the other sites in the Kermanshah province. In the other words orography characteristics of these sites leads to more nocturnally mean wind speed.
The costs of the construction and maintenance of a wind farm include initial Capital Costs (turbine price and costs civil work), and also operation, maintenance and Repair costs. On the other hand, the proceeds from the sale of electricity generated should be borne by the costs incurred. The cheapest turbine is 500- kW machine with 707 thousand dollars and the most expensive is 2000- kW machine with 2900 thousand dollars.
Benefit costs analysis indicated wind power plant construction in Gilanqarb area is more economical than other areas with all turbines except for 1300- kW machines which is more economical in Tazeabad. Also the most economical machine is 2000- kW turbine in Gilanqarb area. The cost of wind power plant construction whit one 2000- kW turbine is 15.4 Billion toman right now, while the proceeds from the sale of electricity generated is 21.49 Billion toman in life time of machine. So this project is the most economical with benefit-cost ratio equal to 1.4 in comparison with other project in the study area. Obviously, the results of economic analysis will also be different if the prices used in economic analysis, such as the price of a turbine, the price of electricity or the exchange rate change.
Conclusion
The results showed 750- kW and 800- kW machines have maximum Operating Probability of wind turbines and also it was the highest in Tazeabad site with 80 to 89%. While Capacity Factor has the highest value for 500- kW machine in all sites. Of course this turbine has the highest value in Gilanqarb (46.4%), Tazeabad (44.2%) and Somar (39.2%) sites. The most Annual Energy Production (AEP) acquired for 2000- kW turbine which is due to its high rated capacity. Calculated AEP for selected turbines vary between about 2 GWh in Kangavar to 6.7 GWh in Gilanqarb in the year.
Benefit-Cost index showed that wind power plant construction in Gilanqarb area is more economical than other areas with more turbines, and also the most economical machine is 2000- kW turbine in this area. Finally Calculations showed that usage of wind energy is not economical with any turbine in Eslamabad-Qarb, Kangavar, Sarpol-zahab, Ravansar, Sonqor, Harsin, Javanrood and Qasre-Shirin.
Volume 23, Issue 2 (5-2023)
Abstract
Accelerated construction methods are extensively used worldwide to reduce the negative impacts of bridge construction on urban traffic. These methods usually require prefabricating parts of the bridge off-site, which reduces on-site construction time and improves the quality and safety of construction. While the use of precast elements for bridge decks is relatively common, using precast elements for bridge piers is a recent development, especially in high-seismicity regions. Prefabrication of bridge piers can further expedite the construction of bridges. Moreover, the use of precast elements can be combined with a self-centering capability, through which the earthquake-induced damage and cost of post-earthquake repairs are greatly reduced. Despite a number of previous numerical and experimental studies on the behavior of precast, self-centering bridge piers, limited information is available on the selection of design parameters for such piers, and important decisions such as the prestressing force needed to achieve suitable seismic behavior remains to a large extent uncertain. This study aims to investigate the seismic behavior of concrete bridges consisting of precast self-centering piers, in which unbonded, post-tensioned tendons are used for self-centering and reinforcing steel is used to dissipate earthquake energy. A two-dimensional numerical model was developed in OpenSees to simulate the behavior of concrete bridges consisting of precast self-centering piers. The model consisted of fiber elements to model concrete and mild steel, as well as truss elements to model unbonded post-tensioning steel. The model also involved the use of zero-length sections to model the bond-slip behavior of mild steel bars. The modeling approach was validated based on experimental results available in the literature on cyclic loading of four bridge piers. To evaluate the effects of various design parameters on the behavior of precast segmental bridge piers, 9 segmental piers with different percentages of prestressing force and reinforcing steel were designed according to 2017 AASHTO LRFD Bridge Design Specifications. All piers were designed to possess similar nominal flexural capacities. The piers were then subjected to monotonic, cyclic, and dynamic time history analyses. The results showed the positive effects of prestressing in delaying cracking and reducing the residual drifts of precast bridge piers. Increasing the prestressing force ratio up to 10 percent of compressive strength of the pier cross section was observed to improve the overall seismic behavior of the structure, above which a further increase in the prestressing level may result in a diminished performance. The optimal value for the prestressing force ratio, which resulted in the most desirable behavior for cyclic and dynamic loadings was therefore found between 0.1 and 0.15. In piers with a prestressing ratio above 0.15, a decrease was observed in the area of hysteresis loops, which was accompanied by negative stiffness of the base shear versus drift curve. Moreover, the residual drift of the pier increased when prestressing ratios greater than 0.15 were used. The maximum drift of the structure was found to be insensitive to the prestressing force ratio. The results of this study are of great value for optimal design of precast, self-centering bridge piers in high-seismicity regions.
Volume 26, Issue 3 (Summer 2023)
Abstract
Introduction:
This study aimed to detect H. pylori genome in dental plaque samples and determine the frequency of the dupA after bacterial culture and PCR assay.
Materials and Methods:
In this prospective study, the inclusion criteria were as: age greater and equal to 20; the need for dental examination performed by a clinician, and finally no record of antibiotic uptake against H. pylori 30 days before sampling. All demographic information of included subjects such as gender, age, history of smoking, and anti-H. pylori therapy was also recorded. DNA was extracted and bacterial culturing was performed within 4 hours of sample receipt. A patient was declared positive for H. pylori when the confirmatory glmM PCR result.
Results:
Of 40 symptomatic subjects, thirty-five were H. pylori positive (87.5%). Among the H. pylori-positive subjects, 28 (80%) were dupA positive. Meantime, for the subjects in the healthy group, 15 cases were H. pylori positive, and among this population 6 patients (40%) were dupA positive (P value <0.05). According to this study, it has been shown that in both groups with a periodontal pocket depth of 3-4 mm and without this depth H. pylori was detectable in the dental plaques, but this rate was significantly higher in the patient group (P=0.023).
Conclusions:
Conclusively, the study can be the initial step in the designation of a specific bacterial gene to track the H. pylori infection and chance of associated diseases in clinical samples while discarding the endoscopic examination as the invasive method is the highest priority.