Sharif Digital Repository

Modification by crumb rubber is a useful means of improving the resistance of asphalt binders and mixtures against rutting, fatigue cracking, and low temperature cracking. Increase binder viscosity and decrease stability at high temperatures are accompanied by most modifiers, and crumb rubber is no exception. Recent research efforts have shown that development of cross bonds across polymer chains and sulfur can improve the storage stability of modified binders. Also, WMA additives can considerably decrease the binder viscosity. This research showed that addition of small amount of sulfur during the crumb rubber modification can improve the workability and storage stability of this binder.... 

A concern in the production sour oil and gas is the corrosion caused by the acid gas H2S. Even though corrosion resistant alloys (CRA) have long been available as a material selection option that mitigates H2S corrosion, the carbon steel is in general more cost-effective for oil and gas facilities. The aim of this study is to investigate the mechanical properties of 410NiMo cladding on a low alloy steel substrate. In this investigation, two successive layers of ER410NiMo were clad on low alloy steel substrates. To reduce the likelihood of Hydrogen Induced Cracking (HIC) and producing stable hydrogen traps, Post Weld Heat Treatment (PWHT) was used. To characterize the mechanical properties of... 

In this thesis, combustion of liquid fuel spray under the condition of hot and diluted oxidizer, has been investigated. To this end, a novel type laboratory-scale test rig was designed to study the physics governing the MILD-Spray combustion conditions with an applied approach. The underlined test rig eliminates the operational problems of its predecessor test stands and is used for a heavier fuel with much more complex chemical composition (kerosene). The test section is axially symmetrical, in which the fuel is injected by a pressure-swirl atomizer in the direction of hot and diluted co-flowing air. With the use of the aforesaid test rig, the effect of variables such as oxygen... 

Gini coefficient is the most prevalent index for the measurement of inequality and is usually extracted by means of nominal variables based on income or expenditures of households. In this study we have extracted more accurate Gini coefficients. By using the raw data of Households Budget Survey (HBS) and STATA software, a special CPI for each household of the sample is extracted. Subsequently nominal expenditures are deflated by these special CPIs, and at last, Gini coefficients are extracted from real expenditures. Our findings indicate that in recent years, extracted Gini coefficients are remarkably higher than prevailing ones.
 

To reduce construction costs selecting the optimal route for water conveyance line entails ample observation and considering all effective parameters. Some part of Aidoghmoush dam project of water conveyance line located in Azerbijan the east has been investigated in this research. First, by investigating, effective factors in determining the optimal route have been identified and then categorized into two groups of quantitative criteria(technical-economical) and qualitative criteria(environmental). Quantitative objectives include: slope, transportation system, infrastructures, fault and soil type. Qualitative objectives include: environmental considerations, land use and land cover. Because... 

Nanotechnology requires a number of infrastructures for reaching its sustainable development. For each step of its development , various infrastructures should be studied and prepared in advance.In this direction, by introducing and recognizing the priority of Iran Nanotechnology R&D indexes ,the present research is going to propose an effective help. In this case, after studying the related literature and gathering the needed data , 27 indexes were recognized. Then , the indexes were divided in 7 criteria.In order to find the priority of the applied indexes , Fuzzy Multiple Criteria Decision Making (FMCDM) was applied. As the weighting of 7 criteria had been found by FANP , the... 

As you know in lean supply chains, it is tried to: reduce the wastes of resources and achieve more production with lower consumption of resources. This system is very well suited for many supply chains in which the final determinant factors are price and quality. In contrast, recently, the concept of agile supply chain has been introduced, insisting on flexibility and high service level. Opposite to lean supply chain, agile supply chain needs safety stock to be able to respond to market’s changes.
Regarding the dissimilarities of these models –including the disagreement in the allocation of safety stock to nodes– In this thesis, in addition to studying and comparing these two approaches,... 

One of the security issues in database outsourcing scenario is the correctness of the query results. Correctness verification includes integrity, completeness and freshness of the results. Most of the proposed approaches for correctness verification impose high overhead on the components of the scenario which prevents the scenario to implemented in practical applications. In this thesis, we have proposed a probabilistic approach which imposes acceptable overhead for correctness verification of returned results of service provider. The approach uses the previous behavior of the service provider to calculate a trust value toward it which is used to adjust the imposed overhead. In other words,... 

The fascinating subject of heavy fermion physics in rare-earth and actinide systems has been a challenge for theoretical and experimental investigations for decades. Kondo Necklace model is one of the promising models in the study of strongly-correlated heavy fermion compounds, which is studied in this project.One of the methods to diagonalize a Hamiltonian properly, regardless of system size, is the continuous unitary transformation. In this approach, the Hamiltonian is considered as a function of a flow parameter. The Hamiltonian is transformed to a simpler form (diagonal or band-block diagonal) under a flow equation which is based on applying infinite numbers of infinitesimal unitary... 

Due to the negative effects of conventional plastics on the environment, especially in the packaging sector, extensive efforts have been put to replace these polymers with biodegradable polymers. Starch is one of the biodegradable polymers which has attracted a lot of attentions because of low cost and good process ability. Native starch has the form of granule and can be processed to a continuous phase after gelatinization in the presence of a plasticizer. The resulting material is a biodegradable plastic-like material called thermoplastic starch (TPS) which is processed using conventional technologies, but suffers from low mechanical properties and high hydrophilicity. Addition of... 

Lean Management is a set of modern procedures that uplifted Japanese manufacturers' status in global markets. The core principle of lean management is to eliminate every process or operation which creates no value, directly and indirectly. To this day, lean has been more focused on production. But eliminating the wastes in service organizations in crucial, due to nature of service. In this thesis, first the lean concept and the Middle East bank is discussed and a literature review on lean studies is presented. Then a vision for the future is envisioned and a questionnaire for conducting a Corporate Diagnosis is developed. In the next step, a lean management system for the bank is implemented... 

The development of embedded systems in safety critical applications leads to using fault tolerant methods to improve their dependability. Among the various fault tolerant methods, recently, software based methods are more appealing during to the following reasons: 1) They are applicable to the Commercial-Off-The Shelf (COTS) processors and lead to reduction in cost and time to market, 2) Unlike the traditional hardware based internal error detection methods, software based methods fault coverage are more promising, and 3)Software-based methods are cheaper, quicker and do not require any hardware modifications. The technology scaling trend in recent years, made system more vulnerable to...