Sharif Digital Repository

The daily increase of fuel prices, decrease of fuel resources and the need for controlling environmental pollution, reflect the importance of optimizing the heat recovery in different industries. In the past 20 years, Pinch technology has been considered as a powerful tool used for, recovering wasted energies, optimizing the energy transfer between hot and cold streams and reducing the need for additional services. In this thesis, Pinch technology is used to optimize the process of wafer and chocolate production in one of the KitKat’s factories and different retrofits for the increase of the heat recovery are proposed. urthermore, the data collected at this factory is used to investigate the... 

Nowadays, methods based on deep learning networks are the most effective artificial in­ telligence methods. Although they have achieved success in various fields (such as machine vision and object recognition), practical and experimental cases show the fragility of deep learning networks against perturbations and unwanted changes of the input pattern. All these perturbations must be in a way that the main class of the perturbed input pattern can be rec­ ognized by human, but the network makes a mistake in recognizing its correct class. This thesis seeks a more accurate evaluation by designing adversarial attacks such that the main class of the adversarial pattern is detectable by human... 

This report models the electricity supply network by means of the ESM software. In this model, the distribution company obtains its final users’ electricity demand from three sources: distributed generation plants owned by private sector, distributed generation plants owned by the distribution company and buying from electricity market (Over distribution network). According to the model, the optimum point of operating the network is a point with maximum profit, minimum waste and environmental effects. The optimum point of supply minimizes the network wastes to an optimum extent. In this model, the distribution company can supply the extra electricity to the electricity market, provided that... 

One of the most important concerns in food industry is decreasing the contamination of food and increasing their shelf life. Antimicrobial/antioxidant packaging, an active packaging concept, can be considered an extremely challenging technology that could have a significant impact on shelf-life extension and food safety of meat and meat products. Due to harmfulness of chemical preservatives, their use has been limited and therefore natural antimicrobial/antioxidant agents have become more popular. Propolis is a natural resinous substance, with a high polyphenol content, produced by honeybees and characterized by antimicrobial, anti-inflammatory and antioxidant properties, which make it... 

Enzyme immobilization/drying operations are among the important operations of many biotechnological industrial units. The enzyme used in this study is bacterial alpha-amylase, which is widely used in various industries, including detergents. The production of alpha-amylase enzyme contains a large percentage of water in its composition; therefore, a wet wall tower was designed to conduct the experiments to evaporate the water present in the enzyme liquor, analyze its effects on activity, and also to validate the device. The results showed that in a flow of air around 240m3/hr and ambient temperature of 20◦C, enzyme liquor has a 250% increase in biological activity, which indicates the... 

In this research, we have studied optimization of culture medium and process factors for high alkaline protease production from Bacillus subtilis ATCC 6633 for detergent usage. Five parameter soy bean meal, initial pH, agitation rate, MgSO4, CaCl2 were selected for more studies. At first, one-factor-at-a-time method was applied to investigate effect of each factor separately. Then, optimum condition for maximum protease production was achieved using Minitab software Box-benhnken procedure. According to results, high protease production was seen in soy bean meal, 35 (g/L); MgSO4, 1 (g/L); CaCl2 , 1.5 (g/L); initial pH, 7; agitation rate, 150; inoculum ratio, 12% (v/v). The activity of the... 

The phenomenon of oil drop detachment from solid surface has great importance in many different industries, such as coating, print, membrane emulsification, detergency, and oil enhancement recovery. In our study, we tried to explore this phenomenon. Therefore, we attempted to employ Young equation as force balance for the discussed system which is comprised of n-Decane as oil droplet, aqueous solution (brine) with SDS (Sodium Dodecyl Sulfate), and glass. Also, in order to find governing factors regarding oil detachment process -such as interfacial tension, contact angle, and line friction coefficient- we used an advanced apparatus equipped with horizontal microscope and digital video camera.... 

Biosorption capacity of zinc (II) by biomasses produced from four species of microorganism including two kinds of bacteria (Pseudomonas putida and Streptomyces rimosus) and two kinds of fungi ( Aspergillus niger and Phanerochate chrysosporium) in batch case were investigated and compared. In all cases dried original bio mass and dried pretreated bio mass with NaOH were used. In all cases biosorption capacity of pretreated biomasses were much higher than non-treated biuomasses to the ratio of 3.8 – 1.4 times. Freundlich and Langmuir equilibrium isotherms were used to match with experimental results of this research. Except S.rimosus, all others were completely matched with Langmuir... 

This project related to gas purification according to difference in the deposition point in the fludized bed.The reason for choosing fluidized bed is increasing erosion on wall of bed & increasing on heat transfer compared to other heat exchangers.Separation process, by cooling the wall causes the self- deposition gas phase shifts to solid phase. Solid formed on the wall, act as an insulating layer and greatly reduces the heat transfer therefore part of vessel not used. To solve this problem, the fluidized bed system is offered because the fluid particles can remove the insulating layer beside improving convection heat transfer coefficient. In this work we studied the quantative of erosion... 

In this research, the optimization of culture medium and process conditions for the production of alkaline protease enzyme from Bacillus subtilis ATCC6633 strain for use in the detergent industry has been discussed. Among all the conditions affecting the growth and production of enzymes, the stirrer cycle in the fermenter, which causes different shear rates and is one of the most important factors in the amount of mixing and aeration, was chosen for further study. At first, the results obtained from the incubator shaker were carefully examined, and then different checks were made to adjust the fermenter stirrer speed through diagrams in three flow states: 1-laminar, 2-transitional, and...