فهرست مطالب محمدرضا داودی

Characterized by its Shiite background and the interdependence of religion and politics in governance, the Safavid government bear some significant similarities to the Islamic Republic of Iran and played an important role in shaping Iran's political and social history. The aim of the present research is to examine the causes of the decline and fall of the Safavid government and to investigate the strategies that could have served as a solution to this decline for the Safavids To this end, after a historical investigation, Resaale-ye Teb-ol Mamaalek (the Treatise on State Medicine) written by Qutb al-Din Nayrizi has been chosen as the textual reference to analyze and achieve the research goal. This selection is of great importance due to Qutb al-Din Nayrizi's religious status and his contemporaneity with the reign of Shah Sultan Hussein Safavid (during whose period the fall of the Safavids occurred), and it can significantly reflect the political and social conditions of that era and elucidate Nayrizi's prescriptions for strengthening the political and social foundations of Safavid Iran and overcoming the state of weakness.

Due to the text-oriented nature of the current research, the authors will use the thematic analysis, which is more applicable to written sources. Accordingly, the materials related to the topic were extracted, categorized and coded. Relying on the stated methodological steps, in order to discover the existing topics of the text of  Resaale-ye Teb-ol Mamaalek (the Treatise on State Medicine), the extraction and coding process of the topics in each section has been done by the researchers. Therefore, using MaxQDA software, categories related to the factors of decline and the strategies to prevent it were marked with the symbols Fa and So, and the coding process was carried out.

In the end, the extracted themes were categorized under two main headings: causes of decline and strategies for overcoming the crisis. Through this process, the influential factors in each of these two headings were identified from Qutb al-Din Nayrizi's perspective, and the position of various factors in his thought was recognized. According to the author of this treatise, if the scholars, as one of the important social groups, are weak-willed, worldly, hypocritical, followers of the Sultan, and inactive, the groundwork for societal decline is laid. Nayrizi also mentions "environmental factors," including widespread famine and foreign territorial expansionism, and "divine trials and traditions" as causes of societal decline. 

According to the findings, it can be concluded that this religious thinker classified the factors of degeneration into the following five categories: factors related to the  public, factors related to scholars, factors related to governance, environmental factors, and also divine traditions; he also classified the solutions to deal with it under four categories: solutions related to the  public, solutions related to the scholars, solutions related to governance, and finally, transcendental solutions or divine aid.

One of the most important parts of the safety of each rail network is the fleet cruise control system. All break application processes are carried out in today's modern systems with the help of a system called ATP. This system consists of several units. One of the most important parts of this system is vital digital input and output unit for brake control, which is called VDX. We analyze the automatic train protection system of the made by the Bombardier Company, which is used in the Tehran Metros. Since the VDX unit in this system is responsible for controlling the emergency brakes and the right and left train doors, after examining the unit in this system, a design is presented that, while simplicity all safety and reliability    considerations are observed. as well as the proposed design consists of two processors, four brakes, two controllers for the right and left doors, six relays, six drivers, three flow sensors, a pressure pipe for the brake system and a switch for each door. In addition, the proposed design consists of two processors; four break control circuits, two door controllers, six relays, six drivers, three current sensors, a pressure Cylinder pipe for the brake system, and one switch for each door. Initially, the status of the switches on the right and left doors is checked if the doors are closed, the brakes are released, and if the doors are open, the brakes are engaged. The door status is checked once several milliseconds and opening the doors are considered as an error. The designed system has two units, which act as processor and controller, a fault detection unit, brake interface circuits, and right and left door interface circuits. Fault detection and troubleshooting are performed alternatively within milliseconds. This unit monitors the processors based on high/low signals received from controllers of them. This system monitors the drivers, brake interface & relays via some dedicated sensors as well. Current of the switches help monitoring left and right sides door.

A significant number of engineering structures around the world are exposed to fire on a daily basis. The most important effect of fire on the structure is elevated temperatures, which may reach more than 1000 degrees Celsius and cause not only thermal stresses and deformations but also diminished mechanical properties of materials comprising the structure. Fire-related collapses have been observed in numerous structural fires. However, many reinforced concrete structures exposed to fire do not demonstrate notable apparent damage and survive despite having experienced elevated temperatures before the fire is put out. Estimating the residual strength of such structures is of critical importance when deciding whether such structures can be safely used after fire. Moreover, in many industrial applications, there is a need to concrete that can withstand repeated long-term cycles of elevated temperatures without diminished mechanical properties. The objective of this paper is to investigate the effects of silica fume and fly ash as two widely used supplementary cementitious materials on the residual strength of concrete exposed to elevated temperatures and evaluate while such materials can be of benefit in improving the strength retention in case of heat exposure. Using 19 mix designs, a series of 570 concrete cylinders was fabricated using different water to cement ratios (0.35, 0.5, and 0.65), silica fume replacement ratios (0, 10, and 15 percent), and fly ash replacement ratios (0, 10, 20, and 30 percent). The specimens were cured in water for 56 days, after which they were placed in a rate-controlled large-scale electrical furnace, and their residual compressive and tensile strengths were measured before heat, and after heat exposure for 2-, 12-, and 24-hour heating cycles with temperatures reaching 200, 400, and 600 degrees Celsius. To eliminate the risk of explosive spalling, all specimens were preheated at a temperature of 100 degrees for 24 hours before the main heating cycle. Results showed that the compressive and tensile strengths did not reduce noticeably after exposure to 200 degrees but demonstrated a significant drop after exposure to 400- and 600-degree cycles. In many cases, the residual compressive and tensile strengths of specimens were found to be smaller than those predicted in previous studies. The square root equation widely used in the literature was found to provide a reasonable lower-bound estimate of the residual splitting tensile strength of concrete from the residual compressive strength; however, a linear trend was identified to provide a more accurate estimate for the results of this study. Moreover, due to less scatter, the splitting tensile strength was found to be a better indicator of heat damage in the structure than the compressive strength. The use of silica fume did not result in a meaningful trend in the residual compressive strength but reduced the residual tensile strength of specimens. Fly ash, on the other hand, could increase the residual compressive strength of the specimens but reduces the residual tensile strength. The results suggest that generally, and with few exceptions, these two supplementary cementitious materials are not recommendable choices for improving the strength retention of concrete in case of heat exposure.

One way to diagnose damage in structures is to use their modal strain energy change index. Since occurrence of damage in parts of a structure, in addition to changing the modal strain energy of the damaged parts, also changes the modal strain energy of the healthy parts, in the vicinity of the main damaged elements, false damaged elements will appear, which makes it difficult to identify the main damaged elements. To solve this problem, in the present work a two-step method has been used to determine the location of the damage on the deck of a concrete bridge. In the first step, by finite element modelling and performing the modal analysis, the initial damage index of different parts of the bridge deck is determined based on modal strain energy changes, using a few vibration mode shapes. In the second step, using weight coefficients, the modified damage index for each element is calculated separately, minimizing the number of false damaged elements. The proposed method for calculating weight coefficients is simple and at the same time accurate. The efficiency of this method was investigated in several damage scenarios with an intensity of only 5% in different parts of the deck of bridge. The results showed that, while the initial damage index could not distinguish even 3 damaged elements in the bridge deck from the healthy elements, the modified damage index was able to identify up to 7 damaged elements in different parts of the bridge deck with good accuracy using only 2 mode shapes.

The world has recently faced COVID-19 pandemic. Phobia or panic has been considered as one of the most common mental disorders during various infectious pandemics. Therefore, the present study aimed to determine the psychometric properties of the Covid-19 phobic scale in an Iranian population.

The present study was a descriptive cross-sectional correlational research which was performed on 402 Iranian participants in Tehran (191 females, 211 males). The participants were selected through convenience sampling method by an online survey form. They completed a battery of scales, including the Corona Anxiety Scale (CDAS), the Corona Phobia Scale (C19P-S) and the Corona Virus Anxiety Scale by online Google Form. The data were analyzed using SPSS-25 and LISREL software with descriptive statistics, Cronbachchr('39')s alpha, Pearson correlation coefficient, and confirmatory factor analysis to describe the data, internal consistency, validity, and construct validity, respectively.

The results showed that Cronbachchr('39')s alpha methodchr('39')s internal consistency for the Corona phobia scale was 0.91. Cronbachchr('39')s alpha was reported for psychological, psychosomatic, economic, and social subscales repeated 0.85, 0.83, 0.79 and 0.8, respectively. In order to evaluate the validity, the correlation between the C19P-S questionnaire and its subscales with CDAS and Corona Virus Anxiety Scale was evaluated. The results showed that all correlations were positive and significant (P-value <0.05). The confirmatory factor analysis (CFA) results showed that the four-factor model has a good fit.

COVID-19 Phobia Scale can be used to assess levels of panic in therapeutic settings and identify candidates in need of clinical intervention.

Although natural frequencies and mode shapes can be accurately measured by dynamic tests, error bounds in values of damping estimation can be large. Since damping strongly influences the design and control of structures, efforts are made to find the damping that has the least error. The random and bias errors are the two important types of error in damping estimation of structures via frequency domain methods. These errors can be reduced by choosing appropriate frequency spacing. In this study, the frequency spacing leading to the least bias and random errors for estimation of modal damping is determined. The complexity of the damping phenomenon on the one hand and complexity of the structural behavior of a double layer grid, on the other hand, led to this study. For this purpose, a double layer grid constructed from ball joint system was tested. the modal damping ratios related to the first 6 modes of a double layer grid with the ball jointed system were identified for different frequency spacing via two output only modal identification techniques; namely enhanced frequency domain decomposition (EFDD), curve fit frequency domain decomposition (CFDD). The modal damping ratio estimations identified through the two methods were then compared with the results of the input output identification method of Ibrahim time domain (ITD) as the reference value. The results showed that there is an almost linear relationship between the modal damping ratio estimations and the frequency spacing in each mode. At the frequency spacing of 0.0625 Hz, the modal damping ratios obtained from the output only methods showed the least difference (between 0 to 21.43%) with the reference values. At this frequency spacing, the root mean square deviation of modal damping estimations between enhanced frequency domain decomposition (EFDD) and curve-fit frequency domain decomposition (CFDD) with the corresponding reference values was 0.02.

Neuropathic pain is a common complication of diabetic patients. In these people, the pain reduces the work and social adjustment.

The aim of this study was to evaluate the effectiveness of acceptance and commitment therapy on chronic pain acceptance and the work and social adjustment in patients with painful diabetic neuropathy.

This study was a quasi-experimental study in which patients were randomly divided into intervention and control groups. Participants were all patients with a diagnosis of diabetic neuropathy referred to the neurology department of Farabi Hospital in Kermanshah in 2019. Instruments included Chronic Pain Acceptance Questionnaire (CPAQ) and the Work and Social Adjustment Scale (WSAS). The results of three phases of pre-test, post-test and follow-up were evaluated. Data were analyzed by descriptive statistics, the repeated measures ANOVA, and chi-square tests using SPSS version 22.

The results demonstrate that in the post-test and follow-up phases, acceptance and commitment therapy could improve pain acceptance and the work and social adjustment in the intervention group as compared to controls. In the acceptance variable, the test results within the group showed that the effect of time (P=0.003, F=6.48) and the interactive effect of time and group (P=0.001, F=12.49) were significant. Also in the variables of work and social adjustment, the effect of time (P=0.046, F=3.21) and the interactive effect of time and group (P=0.028, F=3.74) were reported (p>0.001).

Acceptance and commitment therapy can be used as a psychological intervention along with drug therapy to improve the work and social adjustment and acceptance symptoms in patients with painful diabetic neuropathy (PDN).

One of the most effective ways to achieve the desired foreign policy coordinates in the light of Islamic teachings is to refer to a set of views and opinions of influential elites who are familiar with the theoretical frameworks of Islamic politics and have valuable experience in practical politics. In view of this, the present article seeks to answer the question that "politics, while focusing on the field of foreign policy - as one of the most important areas influencing the maximum provision of national interests - from the perspective of Ayatollah Mahdavi Kani. "From the perspective of Ayatollah Mahdavi Kani, the desirable foreigner of the Islamic Republic of Iran is drawn on the basis of what principles."

‌ In order to answer the written question, the method of thematic content analysis and reference to library resources has been used.

After extracting the related concepts, the principles of foreign policy of the Islamic Republic of Iran were categorized from his point of view and it was found that he divided these principles under the three axes of "justice and oppression", "protection of the oppressed" and "priority of legalism and peace". »Explained.

Finally, the fruits of research show that Ayatollah Mahdavi Kani (RA) in the field of politics, especially foreign policy, with a virtuous approach and realism-oriented idealism looks at this field and the above three principles, respectively, the most importance in his political thought. Has had.

Changes in modal strain energy of elements before and after damage is a robust damage detection index. However, in structures like double layer grids which have large number of elements, this method has some problems. First, In large structures this method needs more mode shapes to detect damage through modal strain energy method which in practice is difficult to determine. Second, this method introduce some healthy elements as damaged element. To overcome these problems, in this paper a two stage damage detection technique based on modal strain energy method is presented for detecting damage in double layer grids. First, the Modal Strain Energy Based Index (MSEBI) for each mode shape is determined. Then a data fusion technique based on Bayesian theory is used to combine MSEBI values obtained from each mode shape to find damaged elements. Then Charged System Search (CSS) optimization method which is a powerful optimization method is employed to optimize an objective function based on natural frequency to determine damage severity of damaged elements. To demonstrate the performance of the proposed method, a large double layer grid with 1536 elements and different single and multiple damage cases is considered. Numerical results show that the proposed method can successfully find damaged elements and their severities using only few first numbers of mode shapes and frequencies.

Output-only structural identification is conducted by output data of the structure. These data usually include structural response together with some noise. Success of output-only methods in determining the vibration parameters of a structure depends on the signal to noise ratio (SNR) of the output data. In this paper, the vibration parameters (Natural frequency and Mode shape) of a contilever beam have been obtained using output data which have different signal to noise ratios. The vibration parameters of the beam were determined using modal analysis of finite element model and considered as reference parameters. Then, appropriate input was applied to the beam and the acceleration signal was obtained. To generate noisy data, noise with different powers compared to signal powers were added to acceleration signal. The modal parameters of the beam were obtained using two output-only methods, Peak Picking (PP) and Stochastic Subspace Identification (SSI). The vibration parameters having signal-to-noise ratios greater than 25 (lower noise level) for all considered modes were identified properly. At a signal-to-noise ratio of 0.25 to 25 (higher noise level), it was not possible to identify the modal parameters of the first mode of the beam, but the parameters of the higher modes were identified with good accuracy.

examining the functions of the “Majlis” as one of the components of the political system of the Islamic Republic of Iran-in the intellectual system of Imam Khomeini has special role, "What is the position of the supervisory function among the various functions of the Islamic Consultative Assembly?" To answer this question, the content analysis method and library reference to the collection of Imam Khomeini's Speeches (in “Sahifeh-ye Noor” as the official reference of his statements have been used. Therefore, after extracting the concepts related to the subject, the functions of the Islamic Consultative Assembly have been classified and defined in two pivots of regulation and supervision. By this, the importance of each of these functions is determined and the status of parliamentary oversight is Qualified in different ways. Finally, the results of the research show that, against to the common beliefs that see the legislating as the main function of the Islamic Consultative Assembly, and also the function of this institution in different periods reflects a focus on this task, the founder of the Islamic Revolution of Iran has emphasized on the parliamentary oversight of the affairs and see this status as the main function of the Islamic Consultative Assembly

Space grids are highly modular structures assembled from components that are almost exclusively factory fabricated. The components therefore, are usually produced with high dimensional accuracy, with a high quality of surface finish and they are generally easily transportable, requiring little further work except assembly on site. Because of their modular nature, space grids may be extended without difficulty and even taken down and reassembled elsewhere. One of the most popular types of connectors that are widely used in the construction of double layer grids is the MERO system. The Mero KK space truss system, the first commercially available, is still considered to be one of the most elegant solutions for the construction of space grid structures. The elegance and simplicity of the Mero system means that it is not only used in buildings but also for shop displays and exhibition stands using lightweight materials. Circular tube members are connected to cast ‘ball’ joints at the nodes by a single concealed bolt for each tube. A double layer grid is combination of prefabricated tetrahedral, octahedral or skeleton pyramids or inverted pyramids having triangular, square or hexagonal basis with top and bottom members normally not lying in the same vertical plane. The connector is an extremely important part of a grid design. The type of connector depends primarily on the connecting technique, whether it is bolting, welding, or applying special mechanical connectors. It is also affected by the shape of the members. This system is multidirectional system allowing up to fourteen tubular members together at various angles. The system consists of tubular elements that are connected together by means of a MERO connector. The ball is located at the intersection of the longitudinal axes of tubular elements. The longitudinal axis of tabular element and all the constituent parts of its end connectors are along together. This axis is referred to as axis of member. The MERO system had only one type of standard joint, a sphere with 18 threaded holes and machined bearing surfaces at angles of 45, 60 and 90° to each other. A model of MERO connector is presented in this paper for double layer grid structure. The internal forces in the members of double layer grid are found using SAP software. These forces are applied as pressures on the MERO connector. The deflection and rotation patterns of the connector are studied under different loading conditions using the ABAQUS software. The forces to be applied on the connector are calculated using of displacementg control.
In order to take into account the connector effects in structural analysis, their behavior under combined load should be predicted. In double-layer grids that are an important family of space structures, the main internal forces are axial forces. In the present study, to determine the force-displacement relationship of MERO jointing system, some tensile, compressive and bending simulation tests were carried out on a connector of this type using 3D finite element method. The obtained force-displacement and moment- rotation relationship were used under different load. The results of the finite element simulation with experimental results have a good match. It was also found that in both compressive and tensile loading, the ball came to the plastic stage. Compressive axial force increases the flexural stiffness of the connection and with increasing compressive force decreases the elastic bending moment.

Several studies have shown the dangers of cigarette smoking among daily smokers. However, another group that has recently been investigated is a nondaily smoking group. The nondaily smokers experience the adverse health effects of smoking more than nonsmokers. This study aimed to evaluate the prevalence of depression and anxiety among daily and nondaily smokers.
In this cross-sectional study with snowball sampling, 385 male residents of Kashan were selected and divided into three groups of daily smokers (118), nondaily smokers (114) and nonsmokers (135). Depression and anxiety were measured by the Beck depression inventory and beck anxiety inventory.
The results of the current study showed no significant difference in the prevalence of depression and anxiety in both daily and nondaily smokers (P The prevalence of depression and anxiety among nondaily smokers is the same as the daily smokers. Thus, in both groups, in addition to smoking, special attention should be paid to anxiety and depression disorders.

Effect of soil-structure interaction (SSI) and site condition on elastic and inelastic seismic demands of structure is investigated in this research. More emphasis is on Effect of soil-structure interaction and site condition is assessed by using earthquakes recorded on different site classes C, D and E (NEHRP [1]) where SSI has a significant effect on the structural demands because of noticeable difference between the stiffness of soil and the structure. In order to develop a comprehensive statistical parametric study, the structure is modeled as an elastic-plastic single degree of freedom (SDOF) system and the soil beneath the foundation is supposed as a homogeneous half space and is idealized by fundamental lumped mass parameters based on the concepts of the cone model (Wolf, 1994[17]). To consider the frequency dependency of soil’s dynamic stiffness in this model, the soil is represented with a three-DOF system that introducing an internal DOF in the soil can represent this effect. Then the whole of soil-structure model is analyzed under 45 earthquakes recorded on previously mentioned site classes. A parametric study is done for a wide range of non-dimensional parameters controlling the SSI effects on structural demands. It is concluded that SSI affects on structural seismic demands such as elastic and inelastic strength, strength reduction factor, ductility demand, and inelastic displacement ratio especially for structures located on site class E. Results exhibit remarkable differences in comparison to fixed base one. Consequently, in some cases, using parameters derived for fixed base case, lead to non-conservative results in design and assessment parameters of structures located on soft soils.

Due to the some uncertainties during manufacture and assembly of double layer grids with ball joint system, the behavior of this jointing system in the structure is different from the behavior of individual and discrete joints. In the present work, the behavior of a ball joint system has been determined in true conditions of its operation in a double layer grid by the general framework of inverse problem. A full scale double layer grid was constructed using ball joint system. A series of modal testing were performed on the double layer grid in free-free support conditions and its FRFs (Frequency Response Functions) were measured in appropriate degrees of freedom. Using the measured FRFs, natural frequencies of the eight vibration modes of the grid were extracted. A beam element was used at each end of members in the finite element model of the grid in order to simulate the ball joint behavior. Through modal analysis of the finite element model, natural frequencies of the eight vibration modes of the grid were calculated for different section properties of the joint beam element. With the finite element model updating of the grid through reduction of difference between its experimental and analytical natural frequencies, section properties of the beam element representing behavior of the ball joint system in the model were obtained. Whilst the updated model resulted in a very good approximation of the natural frequencies of the double layer grid, a flexible behavior in different degrees of freedom was obtained for the ball joint system. Also, the analytical frequency response functions that were calculated using the obtained section properties for the joint beam element, had a good correlation with the experimental ones.