Sharif Digital Repository

Optimizing the energy consumption of air conditioning systems has gained great importance in recent years. In addition, maintaining thermal comfort and air quality in buildings is important. The multi-evaporator air conditioning system, which is a direct expansion system, shows the complex and distributed structure of air conditioning systems due to the thermal connection between zones and its large scale. The modeling of these systems is associated with uncertainties. Therefore, designing a suitable control structure for multi-zone systems is very important to achieve optimal energy consumption and maintain comfort conditions in the presence of uncertainty. Model predictive control has been... 

Reliability analysis in engineering systems is one of important parts in design stage. Stress-Strength method is a method for reliability analysis in engineering systems. To obtain reliability, stress and strength distribution functions should be known, but these functions depend on design parameters and mostly these parameters are unknown. Usually obtaining exact stress and strength distributions is difficult and there is some uncertainty in distribution functions and their parameters. Also, weakness and uncertainty in data makes it difficult to calculate exact stress and strength distributions. In the case, when data is weak, results in point estimation methods (for example Maximum... 

The AASHTO Standard Specification defines diaphragms as a transverse member between girders in order to maintain sectional geometry. Some of the reasons in favor of using a diaphragm are that it prevents the girders from twisting during the process of construction and helps in distributing vertical live loads between girders and transfers lateral loads (wind or earthquake) to supports. It also provides restraint for the lateral-torsional buckling of the girders. While diaphragms at the ends of bridges are called end diaphragms, the diaphragms away from the bridge ends are called intermediate diaphragms. These members are usually made of steel or cast-in-place concrete. Based on their... 

In this study, catalyst-free hydrothiolation reactions of unactivated terminal alkynes by dithiocarbamic acids have been investigated via computational chemistry approach and by Gaussian 09, GaussVeiw 5.0, and Spartan '14 V1.1.4 software from the perspective of the reaction mechanism, transition state, and the distribution of products. The calculation results have shown that the various in situ produced dithiocarbamic acids addition to unactivated terminal alkynes in which the alkyl group attached to the carbon 2 is an aliphatic hydrocarbon alkyl is through Markovnikov type path and this product is thermodynamically more stable which is in agreement with the experimental results. The NBO... 

Dithiocarbamates have demonstrated extensive applications as synthetic intermediates in the synthesis of functional groups and heterocyclic rings. These compounds, due to their high nucleophilicity, are capable of reacting with a wide range of electrophiles, including aldehydes, alkyl halides, azo compounds, diazo compounds, and many others, yielding diverse and valuable products. This project aims to investigate the reaction of dithiocarbamate salts with fluorinating agents for the synthesis of thiocarbamoyl fluorides. Initially, dithiocarbamate salts were prepared via the reaction of amines with carbon disulfide and the presence of an inorganic base, followed by their conversion to target... 

In this study the behavior of buried pipes under permanent ground deformation (PGD) ef-fects caused by reverse faulting is investigated by means of both experimental and numeri-cal approaches. A total number of 7 full-scale experiments on buried steel pipes subjected to a fault offset of 0.6 m along the slip plane is carried out and the effects of different pa-rameters such as pipe diameter (114.3 mm (4ʺ) and 168.3 mm (6ʺ)), burial depth (0.25m, 0.5m, 1 m) and soil type (SW and SM) on the response of the buried pipes are studied. Ex-perimental results show that the pipe deformation shape changes with increasing burial depth from half-sine (for shallow depths) to an S-shape (for moderate to... 

At the first part of project, different kinds of monodithiocarbamates were synthesized.In order to prepare these compounds two methods have been used:Reactions of amines and carbon disulfide in water and finally addition of Michael acceptors.Reaction of amines and carbon disulfide, then addition of alkyl halides under solvent-free conditions.Dithiocarbamate salts are prepared in ether by using CF3SO3CH3 as the methylation agent with resulted monodithiocarbamates at the first part of the project. These salts are found to be ionic liquids, which is important class of organic compounds.At the second part of project, the Michael additions of amines with divinyl sulfone are investigated in... 

This project investigates on synthesis of β-amino carbonyl compounds with new approach to become closer to green chemistry principals.In this project, we investigated the synthesis of β-amino carbonyl compounds with aromatic amines and electron deficient alkenes in the Michael reaction using boric acid and glycerol in water as a green media. High yields of the products and easy handling are some advantages of this procedure. Also, we investigated the Michael reaction in different solvents and temperatures but gave better results in the aqueous media. Moreover, thiomorpholine derivatives were synthesized using this method to give excellent yield.
 

Development of strategically important processes which are environmentally benign with simple methodology and work-up by low toxic material is currently reciving considerable attention.In recent years, dithiocarbamates (DTCs) and their synthesis with a green procedure have received many attention because of their undeniable applications.These synthetic compounds play important roles either in academia and industry. Here a simple, efficient and regiospecific method for synthesis of dithiocarbamates is described by one-pot three-component reaction of an amine, CS2 and alkyl vinyl ether via Markovnikov addition reaction in poly ethylene glycol (PEG) under a mild and green procedure with... 

This research project contains two parts that investigating new approaches for becoming closer to green chemistry principals is clear in it. In the first part we tried to synthesis dithiocarbamate salts using aromatic amins and than Michael addition of them to prepare bifunctional dithiocarbamats. But we found ?-thiols as final product. In the second part of this project, we investigated the regioselective epoxide ring opening with aromatic amines by using boric acid and glycerol in water as a green media. Corresponding ?-amino alcohols were obtained with excellent yields and considerable regioselectivity. High yields of the products, mild reaction conditions, using green catalyst and water... 

Dithiocarbamates are a group of compounds that nowadays have been used extensively in pharmaceutical agents, organicsynthesis and as fungicides in agriculture.We haveshown, an efficient. regiospecific method for the synthesis of cyclic dithiocarbamates by one-pot three-component cascade reaction of an amine, CS2 and α,β-unsaturated aldehyde via Michael addition/hemiamination reaction in watre under a mild and green procedure with excellent yields and complete regioselectivity  

The reaction of α-haloketones with a variety of dithiocarbamate derivatives for the synthesis of various 2-alkylthiothiazole heterocyclic compounds was investigated in this thesis. To this end, different dithiocarbamates were initially synthesized through the reaction of amines, carbon disulfide and various alkyl halides; then, these dithiocarbamates were reacted with α-bromoketones (bromoacetophenone and chloroacetone) resulting in the formation of range of 2-alkyl thiothiazoles. To optimize the reaction conditions, ethanol and water were tested as solvents in the presence of ZrCl4 as catalyst. According to the data obtained, ethanol was selected as the optimum solvent using ZrCl4 as... 

In this study, a catalyst-free Mannich reaction is applied for synthesis of 1,3-oxazines as an important class of biologically active compounds. In order to consider environmental application a mixture of water and ethanol is selected as a solvent for the reaction of 2,7-dihydroxynaphthalene with formaldehyde and an amine. Primary consideration of substitution effect on the reaction revealed that aniline and its derivatives with electron-donating substituent and halogens, cause higher yield. Aliphatic amines are not good substrate for this reaction with the exception of benzyl amine  

Dithiocabamates are valuable compounds due to their wide application as herbicides, fungicides, antitumor and etc. Another aspect of dithiocarbamates is their application in coordination chemistry. In this project, 3-((pyridin-2-yl) methyl amino) propane nitrile was prepared via Michael addition reaction of 1-methyl¬amino¬pyridine and acrylonitrile in water. Then this compound was converted to its potassium dithiocarbamate salt via treatment with carbon disulfide in the presence of potassium hydroxide in tetrahydrofuran. The prepared ligand was used in complexation with metal salts of Zn, Hg, Ni and Sn to prepare their dithiocarbamate complexes. The structure of complexes was elucidated by... 

In the first section, for the first time, a reaction of dithiocarbamic acid salts with carbonyl compounds has been investigated in the presence of BF3.OEt2. The reaction is temperature dependent meaning that the reaction gives two different products at low and high temperatures. At 15-20 0C, the 2-iminium-1,3-dithietane is the main product.As the reaction temperature goes up, formation of gem-bis(dithiocarbamates) is dominant.In addition, deprotection of gem-bis(dithiocarbamates) was investigated by using of nitric acid as the only deprotecting agent. The structure of a 2-iminium-1,3-dithietane was confirmed by X-ray crystallographic analysis.
In the second and third sections, in our aim... 

Dithiocarbamate is one of the most useful components in the science of chemistry. They are used not only in agriculture as fungicides but also in photochemistry in order to determine and analyse NO in biological processes as well as in polymerization routes. Dithiocarbamates which are known as bidentate ligands with high yield are applied in many fields such as producing chemical drugs, functioning as intermediates in organic synthesis, protecting groups in peptide synthesis as well as highly chelating ligands. Regarding the high practically of dithiocarbamates and by focusing on their synthesis process, we have applied them as bidentate ligands. Cinnamaldehyde was condensed in ethanol with...