Showing 17 results for صراف
Volume 5, Issue 2 (Summer 2021)
Abstract
Research subject: In this study, the occurrence of flooding due to the accumulation of sediment in the downcomer area, which led to an excessive increase in liquid on the upper trays of the distillation column was investigated in a refinery.
Research approach: Vacuum pressure in the upper area of the column, boiler feed water flow from the inlet to the condenser and the discharge of the net product as three very important and effective operational parameters in controlling the severity of the flooding phenomena and the amount of coking value as an important laboratory parameter to reduce the volume of inlet sediments entering the distillation column. Data and results of changes made on each of these three operational parameters showed their effectiveness in controlling the severity of the flooding phenomena.
Main results: In order to control and reduce the problems caused by the simultaneous flooding phenomena around the vacuum pump, the boiler feed water flow of the inlet to the condenser and the flow of the net output product were proportionally increased until the operating conditions of the distillation column are normalized. In this study, how to control the flooding phenomena and reduce the adverse effects due to the accumulation of sediments in the downcomer area of tray No. 22 and above was investigated.
To overcome these problems, first the vacuum pump rotation speed was increased from 850 rpm to 1250 rpm and the boiler feed water inlet to the condenser from 1.95 m3/hr to 3.2 m3/hr was increased. On the other hand, in order to prevent contamination of the pure product, the net output product flow rate also increased from 925 kg/hr to 2300 kg/hr. Also, with regular and accurate control of the coking value index as a very important laboratory parameter, the volume of coke sediments in the coal tar feed entering the distillation column was reduced from 37.5% by weight to 18.4% in a 30-day period after centrifugation.
Volume 6, Issue 1 (9-2006)
Abstract
The friction materials are generally consisted of homogeneous dispersed friction materials in a metallic based which produced via a process of compaction and sintering of metallic powders, hard materials, and if necessary lubricant. The role of these materials in the components is transferring kinetic energy to heat and generating torque (brakes and clutches). This research is a property investigation of effected parameters in manufacturing of bronze based friction materials which is used in heavy automotive clutch plates, helicopter brakes, and etc. Four compositions were selected for bronze friction materials and different parameters such as compaction pressure, sintering time and temperature on density, porosity, and hardness were studied. The nearest results to imported samples are: compaction pressure of 5 t/cm2, sintering time and temperature of 30 min. and 820 DC respectively. The wear resistant in [mal sample containing 2% of hardened additives was determined by ASTM G-I05 standard and compared with foreign samples. The sample containing WC had the closest property and microstructure with imported samples.
Volume 10, Issue 0 (بهار 86- 2008)
Abstract
Objectives: The idiopathic minimal change nephritic syndrome (nephrosis) is responsible in 80% of nephritic syndromes in children. It is a clinical entity characterized by inter and outer renal parameters. Main factor in glomerolar damages is proteinuria and the role of IgE is possible. Aim: In this research, serum IgE concentrations were measured in children with nephrosis in three stages: Relapse, Remission in treatment with steroids, Remissions after treatment with steroids.
Materials and methods: Study was done on children under 16 years old that suffered from nephrosis. They treated with Prednisolone. Serum IgE concentrations were measured by ELISA technique.
Results: Average Concentration of serum IgE in the relapse phase was 274.8 Iu/ml (SD=14.6); It was in the remission with steroids treatments 179.59 Iu/ml (SD= 14.82) and it was 234. 9 Iu/ml (SD=14.58) in the remission phase after treatment with steroids.
Conclusion: In some cases IgE is significantly reduced after steroid treatment therefore it seems possible that allergic agents can trigger or increase the disease. Serum IgE concentration was not a main factor in nephritic syndrome.
Volume 10, Issue 1 (Spring & Summer 2006)
Abstract
Generally, planning theories are divided in two sections: first, they study process of planning (procedural planning), second, they study product of planning (substantive planning). This article is studying procedural planning in metro project of TEHRAN metropolis. Namely, steps of decision- making and planning, and their effects have been studied in this project. In this regard, the role of good governance which is included of participation, responsibility, citizenship, transparency, efficiency, rule of law and etc. is studied along with studying the role of people and interaction of government, people and public sector in planning process in this project. The manner of good governance that has been brought up in 1980s is a process that the government, people and public sectors interact with each other. Nowadays this manner is the only way in deliverance of poverty and undeveloped condition in international associations and local management oblige to execute it, because it is the most effective and the most sustainability management way that is following regional development and then national development.
Thus, first generalities has been presented in the field of metro short history (time and cause of metro bring up, designers and partners in planning and execution of this project), then an interview has been carried out with metro incumbents and residents of one of metro stations (Imam-E- Khomeini station of Tehran), in basis of people participation proportion in this project and consideration proportion of good governance principles from metro incumbents. Then these information have been analyzed using descriptive- analytical way and Spss software. Finally these information has been added up and some suggestions have been presented. Results of this research show that planning is carried out in top- down planning and not bottom- up planning, because people didn’t have any specific role in this project planning and execution (bureaucratic and top- down planning), and in this article, principles of good governance have not considered. Undoubtly, this condition is cause of undesirable effects. If metro incumbents aren’t attention for citizenship rights, people won't responsible for this project. And this condition will obstacle regional development and national development finally.
Volume 13, Issue 3 (5-2006)
Abstract
Pithos burial is a common burial method in Arsacids era. Various cemeteries of this era have been unearthed until now but there wasn’t any reference about historical and archaeological condition of Marivan’s region and the existence of pithos because of the lack of enquiry and archaeological studies. Fortunately, by with research effort, some pithos cemeteries with diverse burial from Arsacids era were discovered and excavated. The study attempts to describe some invaluable information regarding migrant Arsacids religious out look and their burial practices near Zaribar lake.
Volume 14, Issue 63 (6-2016)
Abstract
Using nutritionally valuable products is important as people taste is going toward varies foods. The use of pumpkin can provide nutritionally qualified and valuable product, diversity of products and higher customer choice because it contains helpful and therapeutic compounds. In the current research, different levels of modified starch (0.2, 0.15, 0.1 percentage) and micro-crystalline cellulose (1.5, 1, 0.5 percentage) were used in the production of fruit butter for improving the consistency and the texture properties including hardness, toughness, gummy, cohesiveness, chewiness,…. and color attributes including three factors of L, a and b were evaluated. The results showed that the cohesiveness, gummy and hardness decreased with increasing the micro-crystalline cellulose. Furthermore, with increasing the modified starch increased the hardness, toughness, cohesiveness, chewiness, L and b parameters, but it had no effect on gummy, significantly. The pumpkin can be used as a natural and also enrichment combination in the process of the productions such as fruit butter due to its functional properties.
Volume 15, Issue 2 (Summer 2011)
Abstract
Ratio (or reasoning) is the fundamental section of the analogical reasoning. According to Islamic jurisprudence, if the reason is known, the analogical reasoning is authorized. So they have tried to initiative the ways to obtaining the rules reason. Common law system is also based on definition of the judgment reason. According to common law thoughts, it is not enough to achieve similarities but it also should detect the ratio of decisions. Judges distinguish between the ratio of decisions and obiter dicta. It clearly shows that there are common concerns at both the of Islamic law and common law systems.
Volume 15, Issue 2 (7-2015)
Abstract
Most of dyes used in production processes caused serious environmental pollution when discharged into the environment. Azo dyes are the most used synthetic compounds in the textile, food, leather and cosmetic industries. Due to their toxicity and hard degradation, these kinds of compounds are classified as environmental hazardous materials that have to be treated before discharging to the environment. Acid orange 7 (AO7) is one of azo dyes that is resistant to aerobic degradation and under anaerobic condition is reduced to potential carcinogenic aromatic amines. Different physical methods such as adsorption, ultrafiltration, reverse osmosis, coagulation and electro coagulation are widely used for efficient dye removal but they just transport contaminants from water to sludge and generate secondary wastes which need more treatment. Advanced oxidation processes (AOPs) are suitable to mineralize dye wastewater. They are almost characterized by the efficient production of hydroxyl radicals. Radicals are highly reactive oxidant. Ozonation and photocatalytic treatment are often applied for decolorization of dye wastewaters. It is reported that ozone is an effective agent for reducing the color of wastewater especially azo dyes. TiO2 photocatalytic process is safe and does not require expensive oxidants, against ozonation. This process classified as an AOP method and can be carried out at mild temperature and pressure. The purpose of this study was to investigate hybrid photocatalytic and ozonation processes. Therefore, according to debarment of light penetration in dye wastewater, decoloration ability of ozone was used for improving photocatalytic process efficiency in a hybrid process. The effect of pH, dye and nano catalyst concentration, irradiation source power and ozone injection rate were investigated on removal efficiency in this process. Dye removal efficiencies decreased with increase in dye concentration and decrease in pH, ozone injection rate, catalyst concentration and irradiation source power. Optimum conditions of the process was occurred in pH of 9, UV-A lamp of 120 W, and nano material concentration of 128 mg/L with 50 mg/L of dye concentration and 20 mg/min of ozone injected (with 1 bar pressure and 1 lit/min of gas flow). In these conditions, dye removal was completed after 65 minutes. The result confirm the cleavage of the azo bonds, benzene and naphthalene rings as a result of treatment. The intensities of the absorbance peak at 485nm decrease rather fast than 230 and 310 nm. This shows that faster degradation of azo band in comparison with benzene and naphthalene rings. GC-MS analysis was performed to identify the intermediate products of process. According to GC-Mass test, 5-amino-1-naphthol, 1-naphthol and benzene compound (phenol, aniline and phthalic acid) were in decolorized solution. These compounds concentration increased in the first hour and then decreased. 3 and 7 hour were needed to reach optimum condition for removing naphthalene and benzene compounds, respectively. Reaction was followed by first order kinetic and was fitted to langmuir–hinshelwood model in optimum condition in all cases. First order reaction rate of decoloration (K) decreased with increase in dye concentration and decrease in pH, catalyst concentration and irradiation source power.
Volume 15, Issue 78 (8-2018)
Abstract
Volume 16, Issue 1 (8-2013)
Abstract
Objective: In recent decades, β-glucans have been used as important complementary and alternative medicines for numerous immunocompromised individuals and those with end stage of cancer terminal. The most active form of β-glucans is β(1,3)D-glucan and its most common source is cell wall of Candida albicans. Recently it has been introduced as a nano particle design to be used as a carrier for drug delivery. The current study researches a rapid method for the extraction of β(1,3)D-glucans. Methods: The present study was conducted atTarbiatModaresMedicalUniversity in 2012. Candida solubilized β-glucans were obtained by oxidation of the cell wall with sodium hypochlorite and sodium hydroxide. The particle part could be solubilized by treatment with dimethylsulfoxide (DMSO) and zymolyase digestion to extract β(1,3)D-glucan. The soluble fractions were lyophilized. We performed the Callose test to verify the presence of β(1,3)D-glucans. Solubilized fractions were dissolved in D2O and 1H-NMR spectra were measured. Results: The soluble β(1,3)D-glucan fraction which was derived from 1 g of dried Candida albicans germ tube weighed 190 mg. β(1,3)D-glucan was verified by the Callose test and 1H-NMR test compared with Curdlan (standard). 1H-NMR spectra verified the existence of β(1,3)D-glucan in the final product. Conclusion: In the present study, extraction of β(1,3)D-glucan by oxidation of the cell wall using sodium hypochlorite yielded more pure β(1,3)D-glucans in comparison with other extraction methods. Thus it might represent a rapid method of extraction.
Volume 17, Issue 100 (june 2020)
Abstract
Volume 19, Issue 1 (Spring 2015)
Abstract
Urban land management is one of the key areas to achieve sustainable development in the countries. Governments to achieve sustainable development goals have to take specific policies appropriate to conditions of the countries and their communities. In This paper the urban land management studies has been surveyed by using Grounded Theory method as a method of qualitative research(by Using Software of Atlas.Ti)and coding method of information. This research wants to investigate government intervention in the urban land management. The main research questions are: 1) what are the reasons for the ineffectiveness of the policies of government intervention in urban land management and why? 2) What is Suitable model for appropriate government intervention in the urban land management? To answer this question, a combination of quantitative methods - qualitative survey was used. The results indicate that the absence clear vision, and consequently uncoordinated policies and institutions, Centralized and non-participatory decision-making, And high incumbency without the necessary institutional capacity are reasons for the ineffectiveness of policy –making in urban land management. Therefore suitable model for appropriate government intervention in the urban land management is the integrated management of urban land based on ( Formulate a clear vision, and integrated strategic policy, and delegation of authority to the lowest level of local institutions along with the capacity building)
Volume 20, Issue 12 (December 2020)
Abstract
In this paper, the experimental study of partially premixed combustion of methane and oxygen in a 5 mm mesoscale quartz reactor with 1 mm wall thickness and 5, 10, and 15 cm lengths. The partially premixed for 25%, 50%, and 75% mixing ratios paid. Experimental results including the factor of affecting flame regimes, formation range, flame dynamics, the outer wall temperature distribution of the reactor had been analyzing and reporting. The above tests were performing in an asymmetrically centered cylinder combustion chamber and a laminar flow regime. In most partial pre-mixing combustion experiments, the oscillation regime, which had an optimal heat distribution throughout the reactor, had been observed. The flame dynamics were more effect by changes in mixing ratio, reactor length, oxygen flow rate, and finally fuel flow rate (equivalence ratio). Also observed that by increasing the reactor length due to the appropriate time for homogenization of the mixture, differences in the flame formation interval were reducing in the different ratios of the pre-mixes.
Volume 22, Issue 4 (April 2022)
Abstract
An experimental study on the effects of methane-oxygen partially-premixed input flow characteristics in a mesoscale reactor with constant length and geometry was investigated in the present work. For this research, two partially-premixed ratios of 25% and 50% are considered. The reactor is mounted horizontally, made from quartz material and its geometric characteristics are internal diameter: 5 mm, wall thickness: 1 mm, and length: 10 cm. In this research, we have tried to determine the factors affecting flame regimes. The range of flame regimes, flame dynamics, the outer wall temperature distribution of the reactor, frequency, and oscillation of oscillating flames, along with the intensity of the Repetitive Extinction and ReIgnition (RERI) extinguishing sound, were analyzed and reported. This flame's dynamics are more affected by changes in mixing ratio, oxygen volume flow rate, and fuel volume flow rate, causing changes in inlet flow velocity and equivalence ratio, respectively. Examination of the results of acoustic oscillations indicates an increase in oscillating flame velocity with increasing volumetric flow and mixing ratio. Loud extinguishing sound of flames when quenching is caused by converting a portion of the thermal energy of the flame into sound in the flame arrestor and the acoustic vibration waves resulting from the extinguishing of the flame and the difference in gas velocity.
Volume 23, Issue 0 (Special issue 2019)
Abstract
Volume 23, Issue 2 (Summer 2019)
Abstract
Currently, in Iran's legal system, the will of the endower has a crucial role in determining the custodian of the endowment, and the Articles 61 and 75 of the Civil Code assert that no one has the right to change or restrict the power of the explicitly determined custodian, and even in the case of treason the custodian, respecting the will of the endower, the legislator according to the Article 79 of the Civil Code foreseen to add a trustee to the custodian. However, in the legal system of Iraq, the expedient of the endowment and its beneficiaries is preferable to the will of the endower and, in accordance with the Article 19 of the Nezam Al-Motevallin if the actions of the custodian are in contradiction with the material of the endowment and its beneficiaries, due to breach of trust, the privilege of the endowment is dismissed. The results of the study of documents, laws and regulations, and the analysis of the text and content indicate that the approach of the Iraqi legal system that opts for the change of the explicitly determined custodian for the expedient of endowment and its beneficiaries has more positive effects compared with the legal system of Iran while emphasize on to keep the explicitly determined custodian for the respect of the will of the endower.
Volume 23, Issue 3 (Fall 2019)
Abstract
Introduction
Rural areas, as geographical space, have different dimensions that require decision making for spatial development. The spatial development as a rare resource (sarrafi,2015,16) requires strategic policy-making, planning and governance in the current and future situation, so the optimal allocation of the spatial development in territorial policymaking is important; (sarrafi,2015,16) the scope of territorial expansion Rural Settlements, Variety of Territorial Capabilities of Rural Areas in Different Dimensions of Natural-Ecological, Social, Economic and Spatial, Territorial Integration, sectoral and Organizational in Spatial Development (Kidd, 2007), Collaboration Between sectoral and Territorial (Dominic Acid, Ayurte Meijer, 2009), context orientation (Lewis Albert, 2006), integration and participation of development actors Disability (Paul Carynclas, Sophia Hatzpia Neely, 2010) and (F. Van Weillin (2012), Implementation and Policymaking systems, Attitudes toward Rural Development, Policy-Making Policies, Rural Development Laws and Regulations Framework (Dervishes & Partners , 1396) are among the key factors influencing the complexity of spatial organization and the design of spatial development scenarios in rural areas. In this regard, the present study seeks to answer the following questions:
1. What are the key driving forces and alternative futures of spatial development in rural areas?
2- Which scenarios are appropriate for spatial development in rural areas?
Methodology
The present research is applied in terms of targeted and analytical in nature. The method of data collection is based on the use of data collection techniques such as the questionnaire or Cross Impact Matiex, the techniques of reduction of data (factors) Delphi methodology and data analysis techniques are based on cross-impact analysis. According to the requirements of using expert-oriented method, 20 experts and managers of national levels were selected using stratified sampling method. Data analysis has been done using the scenario wizard software, so that after identifying strategic driving force and identifying the alternatives for each of them, in order to measure the effect of different situations on each other , A range of positive effects, ineffective and negative effects were identified. In this framework, based on three attributes, increasing, decreasing and decreasing, the effects of alternative futures were identified in a range of numbers between 3 and +3.
Results and Discussion
Identifying the main driveing for spatial development, mapping of the Cross Impact Matiex and compiling spatial development scenarios in rural areas based on strategic drivers are among the most important findings of the research.
In this regard, research findings have shown that the driving forces of the "policy framework and implementation of the programs", " attitude towards the development of rural areas", "rural development laws and regulations", "oil revenues and rural development" " inconsistency of policymaking-based policy making", " decision-making system (policy-making, planning and goodgovernance) in rural development" has been identified as the main (strategic) driving in the design process of spatial development scenarios. In addition, the propulsion has 19 possible modes (alternative futures).
Conclusion
Based on the results of the Cross-Impact Balance Analysis, 36 scenarios have been developed in scenario-driven software, in which 27 are weak scenarios, 6 are incompatible scenarios and 3 are highly adaptive scenarios. In the meantime, based on the criteria for assessing scenarios, three scenarios with a high degree of adaptability are possible. These scenarios include Zagros Spring, Spring Welcome, and Zagros Autumn, which are derived from a combination of a range of alternatives for six strategic driving forces strategic.
