Sharif Digital Repository

In this dissertation, we are considering the following question: can the Rigidity Thesis (RT) be reduced to the Wide Scope Thesis (WT). According to the RT, proper names of natural language are rigid designators and most of the definite descriptions of natural language are not rigid designators. Thus, the Descriptive Theory of Proper Names (DTPN), according to which the semantic content of a proper name is a (set of) definite description(s), is false. According to WT, the semantic content of a sentence containing a proper name is given by a (set of) definite description(s) with wide scope (over intensional operators, modal operators included). Such a semantic content can explain the... 

The direct reference theory about proper names considers the references of proper names as their contents. This view is persuasive for many philosophers. However, it encounter with some difficulties. Some of these difficulties are related to nonrefering names, called empty names sometimes. If natural language contains such names, the direct refernce theory shall propose some solutions to solve mistakes raised by them. In this project, in chapter one, I will assess the direct reference theory. In chapter two, I will argue that at least some names from natural language are empty. And finally, in chapter three and four, I will put forward some ways to take out of difficulties raised by empty... 

In this paper we seek to find the contribution of groundwater in irrigation agriculture in Iran. We use nationwide panel data of agricultural production in the period of 1993-2013. The results show us differences in productivity of agricultural outputs due to availability of groundwater. Panel data allows us to control regional factors like soil fertility affecting the productivity. We are looking for the main contributors to groundwater usage. Population growth in demand side and groundwater availability in supply side seem to be the most important factors  

Suppose the edges of a graph G are assigned 3-element lists of real weights. Is it possible to choose a weight for each edge from its list so that the sums of weights around adjacent vertices were different?
A graph G = (V;E) is called (k; k′)-total weight choosable if the following holds: For any total list assignment L which assigns to each vertex x a set L(x) of k real numbers, and assigns to each edge e a set L(e) of k′ real numbers, there is a mapping f : V [ E ! R such that f(y) 2 L(y) for any y 2 V [ E and for any two adjacent vertices x; x′
Σ e2E(x) f(e) + f(x) ̸=Σ e2E(x′) f(e) + f(x′)
Is it possible every graph is (2, 2)-total weight choosable and every... 

Masonry infills are vastly used as surrounding walls and partitions. Presence of infill in a building causes some change in strength, stiffness, period and generally seismic behavior of the structure.Mainly there are 5 modes of failure including 1- interface cracking 2- sliding along bed joint 3- diagonal cracking 4- corner crushing and 5- ultimate failure. According to these failures, three stages of strength as shear strength, corner strength and ultimate strength can be defined.Diagonal crack can be calculated by slip surface method grown in Sharif university of Technology. Based on this method the strength of infill wall falls down as the cohesive strength of mortar loses and so the slip... 

The purpose of this research is evaluating of how the concrete filled composite tube column performs. Nowadays in the construction industry, a new kind of composite column called concrete filled composite tube (CFCT) columns, have become very common. Concrete and composite tubes posses’ complementary performance. Because on one hand, the composite tube makes proper confinement for concrete, on the other hand the concrete prevents internal and local buckling of the composite tube. One of the major advantages of the concrete filled composite tube columns compare to the reinforced concrete column is that there is no further need for reinforcement and molding, which results in swifter... 

In 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 investigationson claim management, 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... 

In this research, modelling of pyrolysis in small-scale and a method for calculation of kinetic parameters; activation energy, pre-exponential factor, and model function, have been presented. Calculation of activation energy and frequency factor without any assumption on model function heve been done by presented method. Because, incorrect assumption on model function can be cause to error in estimated values of activation energy and frequency factor.For a bench-scale sample, the heat transfer and mass conservations equations influence the pyrolysis process. In this research for the investigation of kinetic parameter effects, a simple pyrolysis model was presented to predicting the mass flux... 

The use of microorganisms to remove or produce a substace is a fundamental part of biotechnology. An example is the bioreactors for phenol removal in wastewater. Biological processes are commonly done in batch reactors in which suspended cells grow in the liquid phase. The batch process needs alternate reactor washes and alternate cell cultivation, which leades to a longer time constant for for each batch. If these reactors operate in continuous conditions, the cells will leave the reactor in liquid flow, and high cell concentrations will be impossible. The biofilm layer makes a batch phase, so the liquid phase flows in and out continuously, but the cells in the biofilm layer stay in the... 

Cancer has been known as one of the main reasons for disease-related deaths in the last decades. Early diagnosis could significantly reduce the level of fatality chances. Among the known cancer types, lung cancer is one of the most malignant ones. The common diagnosticmethods are expensive and using high-technology methods; therefore, the introduction of simple and cheap methods is very urgent to detect it. In this project, surface and interfacial tension measurement of cancerous and normal lung cells have been investigated as an easy detection technique. Among the common measurement methods, Pendant Drop and Capillary height techniques have been utilized in this research work. The obtained... 

The formation of gas hydrates in oil and gas industries has been the subject of long-standing problems. For example, the hydrate formation may occur and block gas pipelines which can lead to safety hazards. All of these will result in catastrophic economic losses and ecological risks. Therefore, various methods were developed to mitigate the formation of gas hydrate. In many cases, the hydrate inhibition by adding kinetic and thermodynamic inhibitors to the system is the only viable option. But recently using ionic liquids as novel hydrate inhibitors and the discovery of dual function thermo-kinetic inhibitors have been studied. In this project the performance of six imidazolium-based ionic...