In fixed bed reactors, velocity distributions have a direct effect on heat transfer properties. Therefore, in this study we first examined different flow models and solved the modified Brinkman flow model numerically where cannot be tackled analytically. Then, from a heat transfer point of view, plug and non-plug flow models with respect to velocities obtained from the modified Brinkman model have been solved and its effect on Biot number have been examined. In this paper, it has been shown that the correct choice of flow model can have a great impact on the heat transfer properties of such systems.    

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Considering reservoir sedimentation phenomenon and turbidity current as the major factor of happening problems (such as reducing water storage capacity, water passages and gates clogging, depositing in water conveyance channels, reducing water resources quality and etc. ) which cause environmental and financial damages, it is essential to study the various aspects of turbidity currents in creating sustainable management of reservoirs as the main source of water and energy supply. Almost all of the research studies, so far, have been conducted under experimental conditions on rigid beds. In this study, in order to achieve more realistic results regarding to natural conditions in rivers and reservoirs, the experiments were conducted on a mobile bed. Since the body velocity profile of turbidity current has an important effect on generation and destruction of different types of bed forms, characteristics of the body velocity profiles were analyzed on a rigid and erodible bed for different effective hydraulic conditions. In this study, at first according to Special Specifications of turbidity current (very low velocity in small experimental flumes), comprehensive study had been conducted on bed material properties and its required pre-experiments. Finally, the properties of the material used in this study were 450 µ m of average diameter (d50), 1070 kg/m3 specific gravity (ρ s) and 1. 45 of standard deviation (σ g). In order to simulate the turbidity current, an experimental model consisting of an inclined flume with length of 780 cm, height of 70 cm and width of 35 cm, was used. Bed material was situated at the bottom space of bed with height of 8 cm and length of 4. 5 m. velocity profiles were determined in four cross sections (at the certain distances of 1. 5, 2. 5, 3. 5 and 4. 5 m from the gate) using acoustic Doppler velocity profiler (DOP 2000). Overall 48 experiments were conducted which included 36 main experiments on mobile bed changing flow discharge (1, 1. 5, 2. 5 and 3. 5 l/s), bed slope (0, 1. 5%, 2. 5% and 3. 5%) and volumetric concentration of sediment (15%, 20% and 25%) and 12 control experiments on rigid bed at flow discharge of 1. 5 l/s. According to the results, with increasing in the flow concentration, due to increase in flow momentum, in both rigid and mobile bed condition, flow velocity was increased. It is considerable that the percent increase in velocity with change of concentration, was less in mobile than rigid bed condition (about 50%) which could be due to the resistance of the bed material particle and especially bed forms roughness against the flow as long as the bed form is generated. Exactly in experiment condition with bed slope of 2. 5 and 3. 5%, in which the bed forms were washed out and destructed due to increase in bed shear stress, the increasing trend of flow velocity got improved. Also, in all the experiments, the values of maximum velocity in the mobile bed condition decreased specifically and the percent of decrease increased with increasing in the bed slope. Since the bed material particle are active in mobile bed condition, therefore the bed roughness and resistance increases so that acts as resistant force against the flow and results in decrease in flow velocity (up to about 30%). Comparison of dimensionless body velocity profiles in all experiments showed that the maximum ratio of z/h (the boundary between clear water and a concentrated flow) was more in rigid bed condition (with average value of 2) than the mobile bed condition (with average value of 1. 5). This decrease of z/h ratio in the mobile bed condition (about 25%) was due to decrease in average body velocity profile which caused increase in the elevation corresponding to the same velocity of rigid bed condition. The value of z/h ratio was more in the experiments without bed form which were in accordance with results. In addition, the maximum value of u/U in mobile bed condition was less than rigid bed condition. This confirmed the body velocity decrease in mobile bed condition which was more in the experiments with bed forms. The research data, especially dimensionless velocity profiles in supercritical flows, also were in good agreement with the results. In the present study generation of bed forms leaded to about 40% decrease in z/h ratio and 15% increase in elevation of the maximum of u/U location. Consequently by the results, erodible bed and especially generation of bed forms leaded to decrease the body velocity of turbidity current up to about 30% and also to decrease the rate of increasing velocity, due to increase of current density up to about 50%. Finally, comparison of dimensionless velocity profiles showed that the relative position of the interface of turbidity current was decreased about 25% on erodible bed and even up to 40%, where the bed forms generated.

In some point of view, neither Michel Foucault nor Ibn Khaldun are considered philosophers in the conventional classifications, but both are very  important in intellectual and, of course, in philosophical contexts, especially for those who are interested in the deep study of human life from the perspective of political thought.The main concern of two thinkers, one in the 14th century, the other in the 20th century, is the issue  of power, although neither of them provided a precise definition of it. In this article, an attempt has been made to show the place of power and domination in the political thought of both thinkers by examining the thoughts of two thinkers. And in search of an answer to this question, how did Asabiyyah and industry of religion in Ibn Khaldun's thought and social control through self-technology and discipline in Foucault's thought lead to the expansion of the domination of power? This article is written by analytically comparing the opinions of two thinkers based on Ibn Khaldun's most important book called Muqaddimah and Foucault's late works

In this study, variations in water surface profile and bed topography along a meandering path were examined under different experiment durations. Although several studies have been conducted on sediment and scour in open channels, addressing temporal variations in meandering channels requires independent, merely experimental research. In this regard, a meandering laboratory flume consisting of two consecutive 180-degree bends was used in this study. The test was conducted under clear water conditions and in 6 different durations equal to 0.2, 0.4, 0.5, 0.6, 0.8, and 1 times the equilibrium time (240 minutes). Results indicated that at the downstream bend, lengthening the test time from 0.2 to 0.4, 0.5, 0.6, 0.8, and 1 times the equilibrium time added to the maximum scour by 70, 100, 115, 120, and 165%, and also increased the maximum sedimentation by 30, 25, 45, 45, and 45%, respectively. Moreover, with a comparison made between the average transversal water surface profile for 0, 120, and 240-minute duration tests, it was observed that when these transversal profiles were displaced from 45 degrees to 90, 135, and 180 degrees, the water surface at the inner bank was lowered by 2, 5, and 7% and that at the outer bank decreased by 2, 6, and 12%, respectively.

Study on the reduction of flow energy intensity in order to reduce damage of the downstream hydraulic structures, always has been one of the potential interesting issues. One of the most important topics in this field is the study on hydraulic jump and its control method. Like other structures, in energy dissipaters considering economic and ease of construction is an essential issue. Therefore, in this study, the effects of the roughness and negative bed slope on water level and velocity profiles of hydraulic jumps for upstream flow in Froude numbers ranges of 4.9-7.8, with three different bed roughnesses and slopes of 0%, 3.1%, 60%, and % 2 were studied. The results indicated some similarities between the measured velocity profiles and some differences between the profiles of water jets as compared with those on smooth beds. Also, the thickness of the dimensionless boundary layer was calculated to be 0.66, which was significantly different in comparison with its value for the flat bed (0.16). Moreover, the bed shear stress on the rough negative sloping bed was at least 10 times greater than the shear stress on the smooth flat bed. Also, the energy and momentum correction coefficients were higher relative to the classic mode.

One of the most frequent rules in various areas of demonstrative jurisprudence of Two Major Sects of Islam religion is a rule that is known among Shīʿa as “tolerance in the evidence of traditions” (Arabic: التسامح فی أدلّة السنن) and in Sunnī as “latitudinarianism in documents” (Arabic: التساهل فی أسانید). Believers in the general application of this rule have based it for reasons such as consensus (Arabic: إجماع), tradition famous through practice (Arabic: الشهرة العملیّة), and rational judgement (intellectual judgement) and a group of aḥādīth (Arabic: أحادیث, plural form for ḥadīth, literally “talk” or “discourse”) called “Akhbar-e- Man Balagh” (Arabic: أخبار من بلغ). The understanding of the aforementioned narrations and the extent of application of this rule has caused a conflict of opinions among scholars. The narrations containing the excellences of suras of the Holy Book of Quran is one of the fields of application of the rule of tolerance. The present research has explained the types of exposure to this group of narrations based on the rule of tolerance by using descriptive-exploratory method and using library sources and seeks to find a suitable approach about narrations of the excellences of suras (chapters) of the Holy Book of Quran. The interaction with these narrations is organized based on a special reading of the rule of tolerance in the selected approach, which is based on a rational interpretation of the contents of Man-Balagh (Arabic: من بلغ)’s narrations and is compatible with the indications of some verses and traditions. The use of weak narrations containing the excellences of suras (chapters) will be permissible based on this approach considering three conditions and without any certainty of attributing these narrations to Sharʿ (Islamic rules).

How to profoundly change the beliefs of the polytheists during the age of revelation from the denial of the Prophet (pbuh) to the certainty of his Message and the acceptance of his full guardianship is a question worthy of attention. The order of verses about prophecy based on the order of revelation is the reason to lead a transformative process and a special Quranic method in institutionalizing the belief of prophecy in the lives of Arabs. In the first stage, the Holy Quran in the first Makkī (Arabic: المکّیّ, suras revealed in Mecca) chapters has prepared the community from the motivational side to accept the truth of the Prophet’s (pbuh) prophecy and briefly stating the key issues surrounding it. The Holy Book of Quran at the time of the emergence of oppositions and doubts (the second stage) destroyed the arguments of the polytheists and explained the prophecy and proved its authenticity from a cognitive perspective in the second stage by presenting clear arguments. and the Holy Book of Quran in the third stage after Madanī (Arabic: المدنیّ, suras revealed in Medina) period has undertaken measures in order to fulfill the goals of the Massage by explaining the true position of the Prophet (pbuh) to deepen and operationalize the Prophetic belief through explaining practical duties for the Prophet (pbuh) and behavior based on the acceptance of Walaya (Arabic: ولایة, meaning “guardianship” or “governance”).

The current research was conducted with the aim of identifying the employment competencies of educational graduates from the perspective of view of employers. This research was applied in terms of purpose and was among the qualitative researches of Grounded Theory type. The participants of this research included 24 employers in the field of educational (interviewers for the Education recruitment exam, directors of non-state educational institutes, directors and recruitment officers of non-state schools, directors of kindergartens and preschools) in Birjand city. Data were collected using semi-structured interview and analyzed by Strauss and Corbin method and using MAXQDA-2020 software. In order to validate the research, two methods of member control and peer review or feedback were used. Consecutive review and comparison of data resulted in the extraction of 28 categories and 6 themes. Data analysis led to the formation of a sub-theory. The model shows that the focal variable is the process of education and teaching skills. The focal variable, under the influence of contextual and intermediate conditions, leads to the formation of the strategies of "being a lifelong learner", "research skills", "planning skills", "classroom skills and classroom management", "purposefulness" and "problem solving skills". became Finally, "increasing employability" was the consequence of this process.

Considering the fact that the words in the intra-religious attitude are considered in two ways, the first is towards jurisprudential words and the second is a rational and conceptual view focusing on their meanings. we have tried to deal with one of the most important issues of intra-religious attitude with a rational approach by descriptive and analytical method, which is the category of "hermeneutic interpretation" of words, especially the most influential idea of interpretation & that is the view of the "spirit of meaning" of Ghazali. After Ghazali, Ibn Arabi used this theory of Ghazali regarding the development of meaning in creating his new idea, and by re-reading Ghazali's idea with a mystical approach, he presented his own theory regarding the expansion of meaning. While accepting the argument of the focal point of the theory of the spirit of meaning, he removes it from the exclusivity to the "linear", and for this purpose, he brought up arguments as well as the Conditions of Hermeneutic Interpretation in this regard. Ibn Arabi's arguments on transversal interpretation include new formulations in the argument, which after him, this theory was favored and accepted by Mulla Sadra, and then it was accepted by his students.