فهرست مطالب محمدباقر اسدی

The aim of this research was to produce a diet beverage based on aloe vera and investigate its physicochemical, microbiological, antioxidant, and sensory properties. To achieve this goal, aloe vera gel at concentrations of 5%, 5.7%, and 10% underwent heat treatment at 80°C for 30 minutes (Treatment A) and 90°C for 3 minutes (Treatment B). Aspartame was added at concentrations of 100, 150, and 200 ppm, and the beverages were stored for a period of 31 days. The study was conducted using a fractional factorial design with 34 samples under investigation. Optimization was performed based on a maximum amount of 10 gr of aloe vera, 200 ppm of aspartame, and a minimum amount of 5 gr of aloe vera and 100 ppm of aspartame. The use of the sweetener aspartame was highly effective in improving the taste of the beverage, as it provides a much sweeter sensation compared to saccharide sugars and is beneficial for diabetic patients. Based on the microbiological test results, the heat treatment (pasteurization) was successful. Furthermore, sensory evaluation showed improvements in taste, aroma, texture, and mouthfeel with the addition of aloe vera gel to the samples with no undesirable characteristics observed. After determining the models and variable combinations using the Design Expert software, an optimized sample was introduced, containing 200 ppm of aspartame, 10 gr of aloe vera, and the optimized pasteurization process, which was Treatment B for 30 minutes. The results of this study indicate that a vegetable-based diet beverage containing aloe vera can be successfully produced as a beneficial product with desirable sensory characteristics that are acceptable to consumers.

In this note, considering the main properties of closed ideals of C*-algebras, we will determine the structure of closed ideals of the C*-algebra C(X, A), the space of all continuous functions from compact Hausdorff space X to C*_algebra A. Indeed, we will show that for every closed ideal of C(X, A), there is some closed subset F of topological space X × prim(A), such that {f ∈ C(X, A) : ∀ (x, P )∈F , f(x) ∈ P}=I.

In this paper, we study the theory of dilation in operator algebras by introducing theorems that have the same theme. We propose some important theorems and point out the existence of the same proof idea for such theorems.

In this paper, while reviewing the concept of quantum operator systems and their representation theorems, we study the quantum C*- envelope of a quantum operator system.

By supplying energy for many activities, electricity is one of the most important drivers of industrial development. But, electricity industry is one of the largest producers of polluting gases due to combustion of fossil fuels. This has raised serious concerns about the externalities of pollutant emissions in power generation processes. This paper aims at modeling and estimating the health effects and costs of electricity generation in thermal power plants in Iran based on the Impact Pathway Approach using SimPacts software. Based on our results, the health costs of electricity generation in Iran in year 2014 are more than 110 trillion Rials, which accounts for about 1 percent of GDP in this year. Also, the research results show that combined cycle and gas turbine power plants respectively impose the lowest and highest social health costs per kilowatt-hour of electricity generation. Ultimately, by modifying the fuel mix and only using natural gas as the fuel for power plants, the health costs of electricity generation will be reduced by more than 53 percent.

The optimal design of a tax system has inevitably been deemed as the overriding task for policy makers and economic theorists. In recent years, the significant advancement in economic theory has led to recommendation of more specific policy prescription for taxation. Nevertheless, the policy advices derived from economic theories are partially manifested in the tax policies. This paper, presents a succinct summary of eight key lessons delivered by economists about optimal taxation. It also explores the interplay between tax theories and the adopted taxation policies, per se.

This paper examines the impacts of fuel price reform on the technology mix of power plants and other outputs of the Iran electricity market. In this regard, Iran electricity market has been simulated by using an agent-based model for a long-term period. Then, as a result of fuel price reform, the changes in the outputs of the electricity market, including the average price, average efficiency, capacity and technology mix of generation has been studied and analyzed. The results show that, the current situation of technology mix of power plants is far from optimum conditions. Accordingly, the reform of fuel prices may change the returns and incentives of investment in different technologies so that, technology mix of power plants would face major changes, and by increasing share of more efficient power plants like combined cycle power plants, the average efficiency of electricity production increase from current 36% to more than 55%.

In this essay an attempt is made to provide a brief history of macroeconomics, along with an evaluation of present understanding towards this discipline. However one may assume that the field has envolved viz-a-viz two kinds of macroeconomists, and sinequanon two versions of macroeconomics. Those who consider it an engineering field, and those who construe it as a science. Engineers are aimed at problem solving. By contrast, the goal of scientists is to expound the very meaning of the world and its underpinnig functions per se. As a result, the macroeconomic research is varing between these two fields. In this context, one can observe that the macroeconomists of past decates were more inclined to constructing the analytic apparatus, propounding the theoretical principles, but on the contrary, the so called early macroeconomists were interested to act as engineers to solve the genuine problems of human beings in practice. Nonetheless, these apparatuses and essentials have been lethargic in their responses and impacts on pertaining issues of actual life. Thus, the dynamic and productive interaction between the two contesting views are required for the very existence of macroeconomics, to deal with various layers of human society. But despite the wide range of disparity between the two fields of the same discipline with different exegesis, in toto, one may presume that the smooth flourishing of macroeconomics could basically depends on pari passu with acceptance of its dualism in roles and functions.

On one hand, oil is the greatest energy resource in the world and, on the other hand, because of the role of oil revenue in the economic of oil producer countries, such as Iran,it is vital for these countries. So it is necessary to recognize different affective parameters on oil market for these countries. In this research, we try to forecast oil price as an important variable in world wide oil market by using neural networks and ARIMA model. The results of dynamic forecasts have shown that in all cases neural network has better results than ARIMA model. In addition, the results of this research have shown that by use of OECD inventories as an added input in model and doing a bivariate forecasting (for the first time in Iran) the error of oil prices forecasts will reduce.