Sound is one of the forms of mechanical energy and the two main characteristics of sound are intensity or power and frequency or wavelength of sound.their performance against the incoming sound wave, industrial silencers can be divided into two general groups of resonating and absorption silencers, the main difference between these silencers is the release of sound energy from the channeling system, which is one of the common examples of the use of resonating type silencers, their use in It is the Internal combustion engines that distinguish absorption silencers from the resonator type based on the fact that the main and visible part of the act of muting the sound is achieved by changing sound energy to heat energy.The goal of this article is to design a muffler based on the breaking of sound frequencies resulting from the movement of fluid in the exhaust output of vehicles, which leads to a reduction of at least 50 db of sound and gives the operator enough peace and concentration. In this article, after examining three types of mufflers, absorbent mufflers that use the properties of porous absorbent material to absorb passing sound and are the simplest form of mufflers, have been selected, analyzed and reviewed and are suitable for the OM457 engine of Idem Industrial Company. It designed for maximum inlet exhaust temperature is 520 and for the maximum kW power is 315 with the maximum discharge relative pressure of 185 mbar for homogenization with the standard atmosphere.

Preventing from and fighting against speculation, fraud and financial mismanagement are as bases of a resistance economy system. Internal audit is a mechanism that can play an important role in paving the way for preventing fraud and financial mismanagement, through ensuring the Internal controls effectiveness. Such a mechanism itself must work effectively to handle this role. According to Internal auditing standards, infrastructure performance assessment helps Internal auditing management to improve the performance quality. This study adopts a classic basic theory approach to extract the model of Internal audit executives' view from performance assessment of Internal audit in Islamic Republic of Iran. The model shows that legitimacy is the main concern of Internal audit managers, which is extracted from interview data using classic basic theory method. It is the first time that this concept presented in the field of assessing Internal audit performance studies.

By prediction of Majlis as a legislatory organ and guardian council as a monitoring organ, it is imagined that securing legitimacy (necessary condition) and efficiency (sufficient condition) of the legislation is occurred simultaneously, but in considering to establishment of Expediency Council and confirmation of Majlis opinions in the matter of differences with guardian council observations the main legitimacy of in laws. The present analytical method in research in the first part, after introduction proposal of issue and reviewing of historical facts which leads to formation of expediency council, we will pay attention to concept of expedience in shi'ite jurisprudence then on this basis it is focused on present ideas in showing of these in laws legal nature.

Islamic history researchers are always eager to know the reasons of decline and fall of Islamic dynasties. Surely the political causes are considered as the most important ones in such context, as they are the base for other factors in decline of the governments. This paper is aimed to survey the political reasons of Mamlukes state using an analytical approach. The findings reveal that lack of national and religious legitimacy had played the most important roles for such a decline. Conflicts among Mamlukes trobes like Boorji and Joolban in addition to heuristic conflict of political power structure have been decisive. The uprisings, which were mainly due to succession crises, expedited their collapse. Finally, decline of their position among Islamic world and Osmanids invasion led to their fall. This paper tries to study the reasons of this issue using desk study method and first hand references, by means of an analytical-critical approach.

Murabaha is an Islamic contract and one of the means of Islamic banks advance. In two ways, Murabaha will be signed: murabaha that a person purchase a commodity and sell with some profit; Murabaha that in addition to the buyer and seller, the bank participates in contract. The bank purchase the commodity from the seller, on the basis of purchase order, then under the murabaha contract, sell to customer with some profit. In this type, bank may sign agent contract with customer. Also it is possible that, the bank issue credit card. In fact, murabaha referred to "Inah'' that was expressed in the Islamic jurisprudence. In this type, the contract is made by combination of purchase order and customer’ s obligation to purchase from the bank, the bank’ s obligation to give agent to customer, payment on the basis of credit card and selling commodity to customer. In this contract, the bank acquires ownership of the commodity, and then sells to the customer. In this agreement, customer’ s obligation to purchase from the bank, is legitimate and takes its binding power from mutual consent. In our law, Article 10 of the Civil Code can be documented for the legitimacy of this agreement. But agency granted by the bank to the customer and payment by credit card, is objectionable and drawback.

This brief commentary seeks to develop the analysis of Daniels, Porteny and Urrutia of the implications of expansion of the scope of health technology assessment (HTA) beyond issues of safety, efficacy, and cost-effectiveness. Drawing in particular on experience in the United Kingdom, it suggests that such expansion can be understood not only as a response to the problem of insufficiency of evidence, but also to that of legitimacy. However, as expansion of HTA also renders it more visibly political in character, it is plausible that its legitimacy may be undermined, rather than enhanced by, independence from the policy process.

The concept of legitimacy is considered a key concept of the modern political thought. The discussion about it has always entailed warning about impending crisis within the political system. legitimacy is a social prerequisite for stability and an efficiency of the political system, when once lost, the political system will no longer be able to perpetuate itself. Political legitimacy has been defined as the emotional and rational acceptance of the fundamental rules of power by the citizens. The acceptance of emotional aspect is identified by the commitment of the citizens to the political system and the rational aspect is identified by people"s acceptance which the rules are in their own interest. An analysis of political legitimacy emphasizes the influence of the two factors (characteristics of the political system and citizenry) on the political legitimacy citizenry characteristics which include the political confidence variable, political participation, a sense of political justice and value orientations. The characteristics of the political system include accountability, performance, procedural fairness, distributional fairness. The proposed model introduces the citizenry characteristics as the untrammeled variables and the political system characteristics as the extra model variable which set the structural ground for political legitimacy. The proposed model of legitimacy was used as a basis of empirical research in surveys in three Iranian cities. Predicted relations between variables in the proposed model were empirically tested and evaluated by the path analysis. The results of path analysis of the legitimacy indicate that empirical data support the proposed mode significantly.

Purpose: To compare the anatomical and functional results of deep vitrectomy with and without ILM peeling for full thickness macular hole.Materials & Methods: 37 eyes of 37 patients with full thickness macular hole (FTMH), confirmed by clinical examination and optical coherence tomography (OCT), enrolled in this clinical trial. Based on the stage of FTMH (stage 2, 3, 4) as described by Gass and the techniques of surgery (with or without ILM peeling) the patients were randomized into two different groups. All patients underwent preoperative Act and at least one OCT image was obtained during the postoperative follow up.After obtaining informed consent, deep vitrectomy and 20% SF6 injection was performed. The patients were unaware of their allocation status. Patients data & surgical outcome were collected and statistically analyzed. Anatomical success was defined as hole closure at postoperative OCT and functional success was referred to any improvement in visual acuity. Macular hole index (MHI) was defined as a ratio of the greatest height to the base diameter of the hole on cross-sectional OCT images.Results: 37 eyes of 37 patients (15 men & 22 women) were enrolled. The mean age of the patients was 56.4±21.94 years and FTMH were traumatic in 13 cases (35%) and Idiopathic in 24 (65%) cases. Twenty cases underwent deep vitrectomy with ILM peeling (ILM group) and the remaining cases underwent vitrectomy without ILM peeling (no ILM group).The mean preoperative 10gMAR visual acuity was 1.38±1 in the ILM group and 1.22±0.13 in the no ILM group, these improved to 0.95±1 and 0.77±0.31 postoperatively in the ILM and no ILM group, respectively (P=0.871). The overall anatomical success rate was 64%. The hole was closed in 70% of ILM peeling and 47% in the no ILM group (Chi-square test, P=0.15). In anatomically successful cases the mean of postoperative VA was significantly improved (P=0.001).In traumatic subgroup, ILM peeling seems did not affect the anatomical (P=0.2) and visual Success rates (P=0.5). There was no significant differences in hole closure rates between the traumatic and idiopathic FTMH (P=0.968). Visual acuity significantly improved after operation In MHI ³ 0.5 group compared with the MHk 0.5 group. The stage of the hole did not affect the anatomical success rate (P=0.52) or visual acuity improvement (P=0.741). Macular hole index ³ 0.5 had a prognostic value for postoperative visual acuity improvement. The hole duration was not related to anatomical success rate but there is an inverse relation between duration of the symptoms and improvement in VA.Conclusion: Deep vitrectomy and SF6 injection was a safe & effective surgical technique for full thickness macular hole and peeling of the ILM seems did not affect the anatomical or functional success rates. The hole duration, stage and origin of the hole (traumatic or idiopathic) does not related to the anatomical success or visual acuity improvement. MHI  ³ 0.5 seems to be a prognostic factor for postoperative visual improvement but not for closure rate.

In order to acquire acceptability and the right to practice sovereignty over people, every rule needs a social logic and/or any other uniting factor for justifying its power. Neither religion nor any other factor alone can play this role in Iran; rather, a collection of factors combined, play this role together. That is to say, rules’ legitimacy in Iran is based on multi-foundations, which we call them as combined legitimacy and it is for this reason that the ruler in Iran is in principle a religious and political representative and in addition to that an administrative, military, cultural representative, and a manifestation of the history and the past of this country. With the descriptive-analytical method and with the help of first hand books and texts related to each period, we intend to analyze these foundations to prove the viewpoint that, in terms of legitimacy, the rules of Iran after Islam until the fall of the Khwarizm-Shahs have a combined or multiple legitimacy.