There are some comments and examples on the qualities that make a panegyric apt-transition a good-one or a bad-one in Arabic and Persian rhetoric books. But a deeper look on the principles of rhetoric and the study of panegyric masters’ poems would lead us to get some more information about this subject. Analyzing some Persian panegyric poems and criticizing the opinions of the Persian and Arabic rhetoricians, this article focuses on the principles of a well-made apt-transition and, for the first time, analyses about thirty examples of weak apt-transitions and reveals their verbal faults.

Condensation is an important heat transfer regime, with vast applications in industries such as power generation and cooling systems. In the present study, the changes in the coating thickness and geometry of hydrophobic areas were investigated on hydrophobic-hydrophilic plates and totally hydrophobic ones, and a no-coating plate was also studied experimentally for the condensation phenomenon. Considering the use of aluminium as the base material, tests such as lithography with positive photoresist was conducted to study the photoresist adhesion to the aluminium surface and its impact on heat transfer, as well as testing the lift-off process to remove the remaining photoresist at the final stage of producing the plates, to improve their surfaces and optimize the major parameters in the production stage. For this study, one type of totally hydrophobic surface and two types of hybrid hydrophobic-hydrophilic surfaces with different widths of hydrophobic and hydrophilic areas were produced, each type in three thicknesses of 200, 450 and 900 nm. Considering the different values of coating thicknesses, the width of the hydrophobic and hydrophilic areas, the heat transfer coefficient and heat flux were calculated for each plate, and the optimal conditions for each plate were determined. Compared to the uncoated plates, the heat transfer coefficient and heat flux for each plate with hybrid hydrophobic-hydrophilic surfaces (width of 860 μm for hydrophilic area and 970 μm for the hydrophobic, and thickness of 450 nm) registered increase by 1.44-2.01 and 1.43-1.81 times, respectively, which were the highest among the plates in the present study.

Explaining the theory of social gap in the Iranian society of the Umayyad transition period, and the subsequent emergence of asociality as a phenomenon in this society from the center of the caliphate can be examined by functionalist analysis. After the Islamic conquest of Iran, the new Arab-Islamic society failed to absorb Iranians. Iranians’ expectations about the improvement in their general situation did not become materialized and their former social gaps not only did not disappear but with the expansion of the tribal system and their status as Mawalis in the lowest stratum, they became an underprivileged society. Using the historical method and an analytical interdisciplinary approach to the theories of social gap and asociality in sociology, the present research aims to explain the role of the social gap within Iranian society in the asociality of the first century A.H.. According to the findings of the research, the existing social gaps in the Umayyad society and asociality within Iranian social strata were caused by the Umayyad political structure. Furthermore, Umayyad discriminatory policies and the existence of social gaps within Iranian society initiated asociality and paved the way for the Abbasid reception in the hope of a better future.

The impact of corporate disclosure quality on macroeconomic issues, including tax noncompliance, is so important to know. According to the growing importance of tax as one of the governmental major financial resources and revenues, it is very important to identify strategies for decrease of tax noncompliance which reduces tax revenues. High quality disclosure of information can be viewed as a regulatory factor that controls the behavior of corporate management and reduces incentives for tax noncompliance, so it is expected that enhancement of corporate disclosure quality will reduce the corporate tax noncompliance. This study, using Panel Data Analysis, examines the impact of corporate disclosure quality on reducing tax noncompliance in Iran. To achieve this, we investigated 40 firms listed in TSE for a period from 2007 to 2011. This study uses timeliness and reliability as two different criteria of disclosure quality and uses a criterion based on the difference between decided and declared tax for measuring tax noncompliance. The results indicate a positive effect of corporate disclosure quality on corporate tax noncompliance reductio.

Nucleos(t)ide analogues, such as lamivudine and adefovir, are effective drugs for treatment of hepatitis B patients. However, long-term treatment with these drugs leads to the emergence of the nucleos(t)ide analogue resistant strains. The impact of nucleos(t)ide analogues on the emergence of HBsAg escape mutations is not clarified. Hence, the aim of this study was to determine HBsAg escape mutations in chronic hepatitis B patients treated with nucleos(t)ide analogues. A cross-sectional study was performed on 50 patients with chronic hepatitis B under treatment with nucleos(t)ide analogues (lamivudine and/or adefovir) and 50 naive chronic hepatitis B patients. HBV DNA was extracted from plasma and S gene of virus was amplified by Nested-PCR followed by direct sequencing. HBsAg gene sequence of the samples was evaluated for detection of HBsAg escape mutations. Among the 100 patients, the following HBsAg escape mutations were identified: sQ101H, sG119R, sP120S, sP127S, sA128V, sG130N, sG130R, sT131I, sM133I, and sY134N. The frequency of HBsAg escape mutations in patients under treatment of nucleos(t)ide analogues was 16% and in naïve patients was 6% (p=0.2, OR=2.98). According to the obtained results, there seems to be no association between using nucleos(t)ide analogues and emergence of HBsAg escape mutations.

The existence of social divisions in Sassanid society has always increased segregation as well as the passive movement of the lower strata of society and the emergence of an escape problem, which caused the fall of the Sassanids in one of the most sensitive regions of Southwest Asia. In this research, which is done using historical method and analysis of the theory of gap and escape in sociology, by asking the question, what was the role of social gaps in the event of escape from the Sassanid government and then its fall by examining the role of Iranian society? And in response to that; The research hypothesis is that the social gaps in the Sassanid government caused the escape of various layer 05s of society in society and due to the Sassanids did not follow the political custom of the Iranian government theory based on adherence to different ethnicities and religions, the grounds for internal and structural collapse. Findings The research shows that the natural existence of social gaps in Sassanid society with the behavior of the government has led to the beginning of their activities and then accelerated the process of escape. From the theoretical study of the gap and escape, it was obtained that the contradictions in the Sassanid society became gaps in the long run, and because the lower layers of this society had the lowest position; As the life of this dynasty increased, they became more and more interested in escapism; In a way, each components of the Sassanid society turned to its local and trade union interests without regard to the previous society and the external powers paid attention.

Increasing the flame propagation speed with aid of centrifugal force proposed by Lewis is a new challenge that can reduce the length of the combustion chamber and thus increase the thrust to weight ratio. In this study, large eddy simulation of premixed combustion of air-propane mixture in a two-dimensional tube with closed ends have been implemented in OpenFoam Software to investigate the effect of centrifugal force on the flame propagation speed. Comparison of numerical solution results with experimental data showed about 8% error in the most critical centrifugal acceleration (3000g). To investigate the effect of the turbulence model, the combustion simulation using the k turbulence model for 3000g, was compared with the LES model and it was observed that the LES model, investigate propagation speed and flame wrinkling with higher accuracy. Considering the flame surface wrinkling parameter, it was observed that at a centrifugal acceleration equal to 4000g, the flame surface wrinkling, suddenly increased and then decreased rapidly that indicates the extinction of the flame. Then, the effect of pipe length on flame propagation speed and flame wrinkling at 2000g was investigated and it was observed that increasing pipe length and distance from the origin of rotation, the induced centrifugal force increased and as a result, propagation speed and wrinkling Increases.

Cavitations phenomenon is one of the sources of inefficiently operation in a centrifugal pump and also cause reduction in capacity of the pump, decrease in head, blade erosion and corrosion, structure vibration and noise. This paper presents a method for cavitation monitoring of pumps using vibration signal analysis of a centrifugal pump. In this study, cavitation phenomena in centrifugal pump have been simulated by an experimental setup. Vibration signals of the pump have been measured during cavity inception and propagation. Finally, the cavitation effects on the parameters extracted from vibration signals using conventional and advanced signal processing methods in time, frequency and time-frequency domain have been investigated. The results indicate sensitive parameters to cavitation in pump which can be used to design a cavitation condition monitoring system based on vibration signals.

The manner of spray the fuel has an important effect on stability and convenient mixture of fuel and oxidizer. Swirl injectors because of formation of uniform spray cone and proper distribution of the fuel have been used in many rocket engines at aerospace industries. Formation and development of air core in the interior stream of swirl injectors and simulation of them is complicated. Double base-swirl injectors have better atomization and have more effective and uniform mixture and combustion. Inner stream has an important effect on spray characteristics. In this article we want to simulate liquid film، air core and spray angle in double base swirl injector. Inner stream of swirl injector simulate with two-phase method and we use air for gas-phase and water for liquid-phase and validate our results with experimental results. Because this way is very cheaper and faster rather than experimental studies.

Functionally graded aluminum matrix composites to the advantage of lightness as same as high hardness and good wear resistance can have many applications in the aerospace and automotive industry, which with more investigations can be reached to the optimum condition by centrifugal cast method. A390 hypereutectic alloy was cast cylindrically as the base alloy with rotational speed of , 1200, 1400, 1600 & 2000rpm by vertical centrifugal cast method. The Microstructures of samples were investigated by optical microscope. Also the volume fraction of reinforcement particles and their hardness from inner wall through outer wall were investigated. It was found because of smaller density of primary Si particles than molten Al, These particles were moved to the inner wall of the samples due to centrifugal force and were distributed from inner layer through middle layer as gradient. The rotational speed of 1400 rpm was chosen as optimum speed and therefore the centrifugal sample with rotational speed of 1400 rpm was chosen as optimum sample.