Sharif Digital Repository

Over recent years, frequent involvements in claims have been inevitable due to unpredictable economic changes and increasing complexities in construction industry. Therefore, even appropriately made contracts are not exempted from claims. On the other hand, construction contract claims are time-consuming, expense-involving and most likely leading to unsatisfactory results. However, there may be some positive outcomes, such as time extension or compensation of damages. To launch investigations, a list of important and frequent claims in oil and gas industry projects of Iran was extracted after a succinct documents review. Further, the most important claim causes were identified through... 

Public participation is counted as one of the main indexes in sustainable urban management. Based on their nature, metropolitan cities has several and complex problems. For this purpose Tehran metropolitan area is selected. Quantitative Strategic Planning Matrix (QSPM) weighted through a made-byresearcher questionnaire. The reliability of the model was verified by Cronbach’s alpha coefficient. Evaluation matrix for internal and external factors was equal to 1.944 and 3.413, respectively. The strategies were classified and prioritize by quantitative matrix. Suitable strategies for Tehran city are as follows: developing a strategic plan in field of social control participatory management for... 

In advanced combined-cycle power plants, significant improvements in the thermodynamic performance are mainly achieved by the development of more efficient gas-turbine systems. This paper evaluates the effect of selected decision variables in the steam system for optimization of Thermal Combined Cycle Gas Turbine (TCCGT) power plant using an iterative exergoeconomic. The design variables were the thermodynamic parameters that establish the configuration both of the steam and gas systems. The design data of an existing plant (Damavand power plant in Tehran-Iran) is used. Two different objective functions are proposed: one minimizes the total cost of production per unit of output, and the... 

Bibliometric, and scientometric approaches are used to provide appropriate tools for evaluating scientific products at local, national, and international levels. Iran, the same as other countries, has many universities and research centers in the field of engineering that Iran's most of the scientific products account for the field of engineering. This study is a descriptive approach using scientometric methods. is The present paper mainly focuses on visualizing the structure of the Iranian scientific publications in the field of engineering indexed in Thomson Reuters (ISI) accessible via WoS during 1939-2011. To draw the historiographical map of Iranian scientific outputs in the field of... 

Based on International Energy Agency studies, achievement of 450 ppm CO2-equivalent emission target in global emission means that the CO2 emissions in 2050 must be reduced to %50 of 2005 level, and this implies that a portfolio of emission reduction policies and strategies need to be exploited through current century. At the present time, Carbon Capture and Storage (CCS) Technology is a dominant strategy among all the long-term carbon abatement strategies in many countries. Nevertheless, its potential as a climate mitigating option will be proved, only if it is implemented in the countries which are developing at a great pace and taking advantage of fossil fuels in order to afford their... 

Trip destination and mode choice are highly influenced by travelers' perceptions and behaviors; selecting a destination and a vehicle for a trip are two interdependent problems. This paper presents and applies a disaggregate joint model for traveler destination and mode choice. The choice model uses fuzzy set and probability theory to deal with the uncertainty embedded in travelers' perceptions and behaviors. The model is structured as a decision tree in which the fuzzy and non-fuzzy classification of influential variables regarding destination selection and mode choice expand the tree. The most influential explanatory variables among all the variables categorized for travelers' household,... 

The present paper focuses on medium-term effects of alternative windfall management strategies for a resource abundant country where the resource revenues are expected to last over a prolonged period. In particular, the trade-off between spending and saving is analyzed within the framework of a recursive dynamic computable general equilibrium model. The model is further validated against historical data available for 2001-2010. The total factor productivity is calculated endogenously in the model based on a function that reflects the changes in factor productivity. The results suggest that saving oil revenues, whether in an oil fund or through physical investment in domestic sectors, leads... 

This study investigated Iranian language students' perception of and familiarity with plagiarism, their attitudes toward their professors regarding this issue, and their reasons for doing so. The participants were 122 undergraduate and graduate language students in Translation, Literature, TEFL, and Linguistics who filled out a validated and piloted questionnaire. Overall, the results indicated that students had different views about the definition of plagiarism and plagiarism was mostly perceived by students as using someone else's words as if they were their own rather than taking someone's ideas without permission. It was also found that in their academic career, students mostly consider... 

Today, managing an organization is concerned with many problems. Adopting proper strategies can promote an organization's survival. This study aimed at developing an appropriate HSSE Strategy for regional operation associated companies of Iran National Gas Company (INGS) using SWOT analysis. The analysis of the strengths, weaknesses, opportunities, and threats of HSSE was carried out and according to the results suitable strategies were recommended. In this regard, senior and junior managers, supervisors, and experts active in regional operation associated companies of Iran National Gas Company participated in SWOT analysis from HSSE angle. Then, they selected the most applicable SWOT... 

Knowing the rate of evaporation from surface water resources such as channels and reservoirs is essential for precise management of the water balance. Few detailed evaporation studies exist for small lakes or reservoirs in arid regions of the world. In this study, monthly evaporation was determined by Bowen Ratio Energy Budget technique (BREB) for Alghadir reservoir (Saveh, Iran) from 1995-2007 and compared with class-A pan. Daily data were obtained from IMO (Iran Meteorological Organization) weather station, located near the reservoir, for all of these years. Some variations have been observed on the estimated evaporation of the energy budget at different years, ranging from 151 cm for 1997... 

This paper examines the role of transportation demand management (TDM) policies on commuters' mode choice in the city of Tehran. The analysis is based on the results of a stated preferences survey developed through the design of experiments approach. Five policies covering increasing parking cost, increasing fuel cost, cordon pricing, transit time reduction, and transit access improvement are assessed in order to study their impact on commuters' consideration of six modes of transportation to travel to work. A multinomial logit model was developed for the 366 commuters who regularly commute to their workplace in the center of the city. In addition to a number of commuting and contextual... 

Vigorous debates have taken place within and between many countries about regulatory policy regimes covering the assessment and approval of genetically modified (GM) crops. In Iran, a very vigorous and hotly contested policy debate concerning legislation covering GM crops occurred between 2004 and 2009, but it was confined within government circles with almost no public discussion. This paper analyses the Iranian policy-making process in the period 2006-9. It explains how and why a stalemate arose in disputes between ministries and departments. The chosen analytical framework draws mainly on the regulation of technological risks and the analysis of public policy-making. It deploys the... 

The purpose of this study is providing a framework for the evaluation of process and content of development programs and evaluating the fourth and fifth law development program of Iran. Policy evaluation is one the most important measures in the policy cycle and is implemented with the purpose of learning from the results of stage. Given the wide dimensions of policy making, achieving a model for evaluating policy is faced with many complexities. In this study with reviewing previous experiences in the field of policy evaluation, an integrated model for evaluating policy, is presented from two main aspects of the process and the content and then with using this model, the Fourth Program and... 

Background: New technologies using hazardous materials usually have certain risks. It is more serious when the technology is supposed to be applied in a large scale and become widely used by many people. The objective of this paper was to evaluate the risk of vapor cloud explosion in a hydrogen production process. Methods: Potential hazards were identified using the conventional hazard identification method (HAZID). The frequency of the proposed scenarios was estimated from statistical data and existing records. The PHAST professional software was applied for consequence modeling. Both individual and societal risks were evaluated. This cross-sectional study was conducted from June 2010 to... 

A number of challenges including instability, nonconvergence, nonuniqueness, nonoptimality, and lack of a general guideline for inverse modelling have limited the application of automatic calibration by generic inversion codes in solving the saltwater intrusion problem in real-world cases. A systematic parameter selection procedure for the selection of a small number of independent parameters is applied to a real case of saltwater intrusion in a small island aquifer system in the semiarid region of the Persian Gulf. The methodology aims at reducing parameter nonuniqueness and uncertainty and the time spent on inverse modelling computations. Subsequent to the automatic calibration of the... 

This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are... 

Remote sensing is an effective tool for capturing spatial and temporal variations of water surface temperature (WST) in large lakes. The WST of Urmia Lake in northwestern Iran was examined from 2007 to 2010, using MODIS land surface temperature (LST) products. Spatial and temporal (diurnal, monthly, seasonal and inter-annual) variations of Urmia Lake WST were also investigated. Results indicate that the MODIS-derived WSTs are in a good agreement with the in situ data (R2=0.92 and bias=-0.27). Spatial analysis of WST revealed that there are three thermal zones along the lake: the shallow region in barriers of the causeway, islands and the shoreline; the south part; and the deep north parts.... 

The main objective of the current study is to investigate the impacts of environmental evolutions at global scale on Iran's environmental planning. Thereby, all political movements towards solving environmental issues in Iran were accurately reviewed to find out the impressibility of the events by the global environmental evolutions. The findings indicated that Iran has joined the conventions and protocols with a time lag. During the period 1948-1993, the mean time lag between holding an international convention until its approval in Iran was eleven years while from 1994 to 2007, the average lag time was shortened to four years. As the results show, attention to environmental issues was... 

The present study was conducted to investigate the impacts of retrofitted CNG vehicles on air pollutant emissions in Tehran over a 20 years period using available statistical data, precise automobile tests, data analysis, and LEAP Software. The obtained results revealed an increase in air pollutant emissions including CO (equal to 1030.77 thousand tons), NOx (equal to 1030.77 thousand tons), THC (269.02 thousand tons) and CO2 (equal to 38.43 thousand tons) resulting from utilizing retrofitted CNG vehicles within the studied period. Considering the obtained results, if the current trend of producing retrofitted CNG vehicles continues, a total cost of 435 million USD will impose on the... 

The origins and evolution of the Middle Eastern dust storms which frequently impact the residents of this arid region were studied. A methodology was adapted and developed to identify the desert regions of potential dust sources and determine their contributions to PM10 concentrations in the highly-populated receptor city of Tehran, Iran. Initially, the episodes of regional dust intrusion and the resulting amounts of increase in the particulate concentrations during these episodes were determined using a statistical analyzing methodology. The dust episodes were also inspected with the aerosol index information from the Ozone Monitoring Instrument (OMI). The Hybrid Single-Particle Lagrangian...