Background & Objective: Carotid baroreflex is the most important system of moment-by-moment control of blood pressure. In the past, in order to test carotid baroreflex, invasive methods were incorporated. In 1975 Eckberg introduced a non-invasive apparatus for testing carotid baroreflex sensitivity. The main objective of the present research was to design and construct a more progressive version of the Eckbergs model apparatus. This apparatus would be able to stimulate cervical baroreceptors through sucking the neck. This device will enable physiologists and pharmacologists to perform many researches about carotid baroreceptors.Methods: In this apparatus advanced electronic and mechanical ciruits apply negative controlled pressure on the carotid sinus and increase the blood pressure. By application of negative pressure in front of neck, it stretches the soft cervical tissues including carotid sinus. One of the major modifications included was using resistant rubber instead of lead sheets for making the neck chamber. The whole system was controlled by a computer, which made our system more advanced as compared to the original model suggested by Eckberg. In order to test the apparatus, 12 young male volunteers received a -30mmHg to -90mmHg neck chamber pressure for 10 seconds. Any changes in cardiac cycles during the suction were being recorded using cardiopen II. So the charges could be evaluated.Results: The findings showed that stimulation of carotid baroreceptors increased the length of cardiac cycles abruptly. This increase is significantly different from the baseline( p<0.003) and shows the correct functioning of the equipment. Conclusions: The final tests confirmed the capability of the apparatus in stimulating carotid baroreceptors. This device can be used in other universities and research centers.

A new simple shear apparatus which is capable of applying monotonic and cyclic load on soil specimens is fabricated. Cylindrical specimens are placed in a special triaxial type cell where confining pressure, pore air and pore water pressures can be controlled. The apparatus consists of an inner part and an outer portion. The inner portion that is inside the triaxial cell consists of a pedestal attached to a movable base. The movable base is mounted on a pair of horizontal rolling tables, which makes the inner portion capable of moving back and forth, horizontally. The outer portion consists of a cylindrical frame that holds the top cap and prevents its lateral movement. A high air entry ceramic disk is sealed into the pedestal using an epoxy resin. The specimen is sheared in a simple shear mode. The horizontal load required to shear the specimen, divided by the nominal area of the specimen gives the shear stress. Soil suction can be measured using the so-called axis-translation technique [1] by increasing the pore air pressure through the top low air entry disk and recording the pore water pressure through the high air entry ceramic disk. Using the fabricated apparatus it is possible to measure and control the vertical normal stress as well as the all-around confining pressure applied to the soil specimen. Hence, testing the soil under initial isotropic or anisotropic confining pressure could be easily achieved. In this paper, the main features of the apparatus are discussed via some test results carried out on unsaturated soil specimens.

Background: The vertebral column is the second most common fracture site in individuals with high-grade osteoporosis (30– 50%). Most of these fractures are caused by falls. This information reveals the importance of considering impact loading conditions of spinal motion segments, while no commercial apparatus is available for this purpose. Therefore, the goal was set to fabricate an impact testing device for the measurement of impact behavior of the biological tissues. Methods: In the present study, first, a drop-weight impact testing apparatus was designed and fabricated to record both force and displacement at a sample rate of 100 kHz. A load cell was placed under the sample, and an accelerometer was located on the impactor. Previous devices have mostly measured the force and not the deformation. Thereafter, the effect of high axial compression load was investigated on a biological sample, i. e., the lumbar motion segment, was investigated. To this end, nine ovine segments subjected to vertical impact load were examined using the fabricated device, and the mechanical properties of the lumbar segments were extracted and later compared with quasi-static loading results. Results: The results indicated that the specimen stiffness and failure energy in impact loading were higher than those in the quasi-static loading. In terms of the damage site, fracture mainly occurred in the body of the vertebra during impact loading; although, during quasi-static loading, the fracture took place in the endplates. Conclusion: The present study introduces an inexpensive drop-test device capable of recording both the force and the deformation of the biological specimens when subjected to high-speed impacts. The mechanical properties of the spinal segments have also been extracted and compared with quasi-static loading results.

Summary: In this paper، an automated and servo-controlled apparatus is introduced which is capable of accurately conducting shear tests under different boundary conditions including constant normal load and constant normal stiffness. Introduction: Precise and accurate measurement of shear strength of rock joints is of great importance in various projects related to rock engineering such as tunnels، dams، surface and underground mining، and oil shafts. In the laboratory، mechanical behavior of rock joints is studied by direct shear testing equipment. Manually controlled devices of direct shear testing are not adequately accurate. In this paper، development of an automated and servo-controlled device for direct shear testing of rock joints has been described. Methodology and Approaches: The developed apparatus performs monotonic and cyclic shear tests with different rates. It also allows the correction of the involved area with shear displacement and adjusting the normal load accordingly. In addition to the possibility of terminating the experiment manually، conditions can be set in terms of the test duration، shear displacement، shear stress drop، or their combination to stop the experiment automatically. The data acquired by the displacement and load sensors are constantly transmitted to a personal computer connected to the device، and online graphs can be monitored during the experiment. Furthermore، some measures have been considered to remove sample clearance inside the shear box. Results and Conclusions: Finally، the results of a number of direct shear tests carried out by the apparatus on the joints of known surface morphological characteristics are presented.

The basic characteristics of the flow-through cell apparatus (USP apparatus IV) including the assembly and open/closed configuration of the apparatus have been described. The relative advantages of the flow-through cell apparatus over other release setups have been summarized. Finally, potential applications of this setup are presented.      

In order to conduct impact loading test on agricultural materials, a frictionless instrumented pendulum was developed. The apparatus consists of a heavy anvil, with minimum vibration, a pendulum arm with impact weight, graduated plate (scale), a potentibmeter and an electronic data acquisition unit. Technical specifications and dimensions of the apparatus are suitable for testing of various agricultural commodities, including small grains, by impact loading. This apparatus can be utilized to determine: strain energy, kinetic energy to rupture, coefficient of restitution and specific energy. In order to investigate the capacity and technical specifications of the instrumented pendulum, single kernels of five wheat varieties at two levels of moisture content (6.5 and 15%), w.b) were tested. The pendulum was used successfully for rupture energy measurement and related parameters. According to the results, wheat moisture content had a significant effect in coefficient of restitution and strain energy. However, taking into account the grain dimensions (in the form of specific energy), its effect was reduced. The minimum kinetic energy required for causing failure in the dry and moist samples was determined to de 33 and 72 mJ, respectively. Results indicate that it is possible to distinguish wheat varieties based on strength properties extracted from pendulum impact loading test and that obtained data scatter is less than observed in static compression tests.

In any political system or government, there are conflicting forces composed of a multitude of actors (e.g., politicians, activists and other stakeholders) with diverse ideologies that are vying for power to influence the public policy process at all stages from policy formulation and policy execution to policy assessment. Certainly, one of the most significant government policy areas is in the field of education. Contrary to the positivist approach, education policies and strategies are not formed in a vacuum. Outside all political systems, there are individuals and institutions that expectedly endeavor to set the agenda for national education policies. These external actors are often powerful enough to have a determining impact on education policies based on their worldviews and rigid ideological thinking about education.  Even though they might not necessarily oppose policies aimed at improving the quality of education in order to confront both the traditional and emerging challenges of building and maintaining efficient, equitable and forward-looking education systems.The authors try to find suitable answers to the following research questions: 1. Which actors greatly influence Iran’s decision-making and policymaking process in the field of education? 2. What are the ideological thinking and typical demands of each major group of actors influencing Iran’s education policies? In the hypothesis, it is claimed that the weaknesses of competitive mechanism by which political parties, labor unions and non-governmental organizations often crucially influence policymaking in the public sphere have led to a situation in the existing political arena that the demands of stakeholders and actors who are aligned with the dominant political ideology are predominantly considered by the policymakers’ agenda-setting efforts in the field of education. For the purpose of hypothesis testing, the authors use a composite theoretical framework based on Habermas’ theory of public space, Althusser's theory of ideology (and ideological state apparatuses), and Bourdieu's field theory. They relied on the works of these prominent scholars because Habermas's theory of the public sphere offers valuable lenses through which one might be able to examine the intricate interplay between the external actors and the broader public domain. Althusser's concept of ideological apparatus serves as a critical tool for understanding how ideologies are disseminated and mobilized in the education policy arena. Furthermore, Bourdieu's theory of the field provides valuable insights into the power dynamics that shape the education policy landscape.Using the method of critical analysis, the demands related to the material interest, socio-economic needs, and politico-cultural preferences of the key activists and stakeholders (e.g., the Ministry of Education, administrative authorities, professional associations for teachers, student councils, parent–teacher association, seminaries and theological institutions, etc.) as the factors influencing the education policymaking process will be examined. By subjecting these demands to a careful scrutiny within their chosen theoretical framework, the authors attempt to reveal the ideological forces that underlie Iran's education policies. In the hope of overcoming the shortcomings of the country’s education policymaking efforts, a few policy recommendations are ultimately presented in the concluding section, for instance, the necessity to base the education policymaking on an inclusive participatory approach, strengthening the role of all relevant governmental and non-governmental actors working cooperatively in the public sphere, and optimally using the capacity of all major stakeholders’ scientific associations, organizations and labor unions in the field of education in Iran.

Internal erosion refers to the seepage-induced movement of a fraction of soil particles in such a way that the initial state of the soil structure changes. Accordingly, severity and mechanism of the particle movement depend upon the geometric, mechanical, and hydraulic conditions, which is of a higher probability in the case of concave upward and gap-graded soils. Internal erosion is one of the long-lasting challenges in the design of earth dams and engineering fills to which considerable attention has been given. To date, extensive studies have been conducted on the four regular types of internal erosion such as concentrated leak erosion, contact erosion, backward erosion, and suffusion; subsequently, various techniques and criteria have been proposed for identification and assessment of this phenomenon. Hence, the previous studies are mainly focused on the geometric parameters (e. g., gradation, void ratio, etc. ), whereas the mechanical and hydraulic factors have gained less attention. However, most of the studies and experimental apparatuses for evaluating the occurrence of these phenomena in susceptible soils have been in terms of one-dimensional (upward or downward) flow applied perpendicular to the soil layers. There is also no mention of the effect of flow direction and direction of the layers in the existing criteria for evaluating internal stability, whereas natural deposits and even engineering fills are not necessarily perpendicular to the direction of the layers. Also, flow direction towards gravity is not necessarily zero or 180 degrees and may be present in any case Therefore, in this study, a special physical model was designed and developed to study samples of gravel size and different directions of layers and inflow. The results of experiments carried out on gap-graded soils show that the critical gradients are more in soils with perpendicular layers than those with parallel layers. Also, as the angle of flow relative to the direction of gravity increases, the critical gradients generally increase; in addition, the direction of the layers relative to the inlet flow to the soil specimen completely affects the shape of eroded pipes in the soil.