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Background: The role of the hospital environment as a source of dissemination of pathogens is critical. Environmental surfaces in the Intensive Care Units (ICUs) are suitable for the growth of Gram-negative bacteria that normally circulate between the environment and patients and can cause outbreaks of nosocomial infections. In this study, the prevalence of Gram-negative bacilli in the environment of the ICUs and neonatal ICU (NICU) of hospitals in the city of Qom was evaluated. Materials and Methods: During a 6 month period from November 2012 to April 2013, samples were collected from environmental surfaces of ICUs of four hospitals and NICU of one hospital located in the city of Qom. Sampling was done from equipment, fluids, and surfaces and identification was carried out based on culture and biochemical tests for Gram-negative bacilli. Results: A total of 230 swab samples was collected and 50 colonies of Gram-negative bacilli were isolated from environmental surfaces. Overall, 64% of the isolates belonged to non-fermentative bacteria and 36% of the isolates belonged to Enterobacteriaceae family.  Strains of Pseudomonas aeruginosa and Acinetobacter baumannii complex accounted for the highest rates of environmental isolates. In addition, Klebsiella pneumoniae was isolated from NICU. Conclusion: The high frequency of genus Acinetobacter among Gram negative bacteria isolated from environmental surfaces has a public health impact and Acinetobacter spp. should be considered in the infection control programs in hospitals. Isolation of K. pneumoniae should be regarded as a risk factor for fatal neonatal infections.

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  In this article, formation of the first modern state in Iran has been studied within the framework of sociological analysis of agency and structure. Each structure is formed of joint actions,which will be the basis for future actions. Each action, on the other hand, also happens within a structure that can cause its contiouity or discontiniouity. In this article,the aforesaid dialectical effects have been reviewed in a way that social structures on the eve of the conflicts of modernity process in the Constitutional history of Iran will be the reason of social tensions and they eventually turn in to authoritarian political structure to overcome the crises by social forces. The theory construction of this study has been formed by the using of the theory state of "Bertrand Badie" and "Pierre Birnbaum", and the research hypothesis has been extracted based on the relationship between social crises and essence of state. Data collection has been done by documentary method, and data analysis by historical method. The results showed that social crises accumulation in Iran and attitude of social forces towards centralism to overcome the crises of society have paved the way for a weak society and a maximal state in Iran.    

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Considering frictional, inertial and machining forces, the authors have presented an enhanced analysis of a hexapod table as used in milling machines. The Newton-Euler analysis of hexapod’s components has been implemented by a simulation program developed by the authors in MATLAB environment and the results have been verified by those of others. The impact of various loads involved in machining operation carried out on a milling machine equipped with hexapod table has been presented in the paper. This provides a potential machine tool designer with guidelines on the importance of these loads and helps him give appropriate weights to them.

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Abstract Due to various deficiencies, inadequate lateral stiffness, weak design and weak construction, many reinforced concrete buildings are highly damaged during the major earthquakes. One way to retrofit these buildings is to improve the behavior and to prevent the total collapse of the reinforce masonry infilled walls in order to make them behave such as structural walls with composite materials. In this study, the concept of equivalent strut is investigated by finite element modeling and behavior of the compression strut and tension tie is presented to model unretrofit and retrofit masonry infilled walls. Analytical pushover results show great accordance with experimental results.

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During the last decades, many researches have been carried out on development of supplemental passive energy absorption devices especially hysteretic metallic dampers and different types of them with different capacities and potentials have been developed. The idea of buckling of thin-walled tubes and the use of this property was led to develop an accordion metallic damper (AMD) [Motamedi, Nateghi-Alahi-2007]. This damper utilizes the capability of accordion thin-walled tube for excitation of axisymmetric concertina buckling mode as a damping mechanism which in turn increases the amount of dissipated energy. In this paper filled accordion metallic damper (FAMD) is suggested and analytically and experimentally the behavior of AMD's and FAMD's under axial cyclic loading are investigated and compared. For this purpose, Firstly analytical studies based on Finite element method and nonlinear dynamic analysis was performed on FAMD's for the determination of the approximate preliminary specifications of different polymers for potential use. After specifying the preliminary material properties, 4 specimens include 2 FAMD's filled by polymeric foam and 2 AMD's were subjected to dynamic tension and compression actuator and the effect of filling AMD's by this polymeric foam on the some of important specifications of damper studied and try to use this method for improving and developing of AMD's. Based on the results obtained using the appropriate filling inside the AMD's is a suitable technique for the purpose of improvement the some of important specifications such as the number of cycles before failure, amount of dissipated energy and plastic capacity. The effect of interaction between foam and accordion thin walled tubes play an important role for this purpose especially in low capacity AMD's.

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The aim of present study is to investigate the kinematics of tool-workpiece’s relative movement in conventional and ultrasonic-vibration assisted turning (UAT). The kinematic analysis of UAT shows that the movement of cutting tool edge relative to the workpiece resulted from the cutting speed, feed speed and tool’s vibration affects the lateral machined surface of workepiece and leaves a repeating pattern of crushed and toothed regions on it. This results in an increase in the surface hardness of the lateral machined surface in comparison with conventional turning (CT). A model of the tool-workpiece’s relative movement has first been developed in the present study. This model predicts a surface hardening effect for the lateral surface in UAT in comparison with CT. Several experiments were subsequently carried out employing a surface micro-hardness testing machine and an optical microscope to verify the predicted results.

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The spring-back of a work-piece during machining operation causes dimensional error of the work-piece. In the present study, the spring-back of work-piece in ultrasonic-vibration assisted turning and conventional turning has been modeled. It is illustrated that the reaction of the work-piece in high frequency vibration cutting is similar to a static behavior, whereas the spring-back in this process is theoretically and experimentally smaller than the conventional cutting leading to smaller error. A method has also been proposed to obtain the errors caused by rigid assumption of the spindle assembly used for correction of the results.

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One directional and elliptical vibration cutting of IN738 at ultrasonic frequency has been investigated both experimentally and by FEM in the present study. The influence of each process on the cutting force was studied. The FEM modeling was carried out by using MSC-MARC. The results were compared with the experimental findings of the conventional cutting. The ultrasonic vibration was applied to a rigid cutting tool along the cutting velocity in one directional vibration cutting. In elliptical vibration cutting the vibration was applied both along the cutting velocity and in the chip flow direction. The experiments were carried out on an ultra precision CNC lathe with single crystal diamond tools. The same effects were confirmed in the machining practice and by FEM. It was quite feasible when machining IN738 to obtain the advantages of elliptical vibration cutting already reported for some other materials such as copper, aluminum, tungsten and super alloys.

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Objective: As we are approaching the global eradication of wild poliovirus, laboratory surveillance of poliovirus by the gold standard cell culture method becomes increasingly important. As there is a lot of concern about accurate and sensitive detection of imported wild and Vaccine Derived Polioviruses (VDPVs) in Polio-Free countries, in this study we assessed and compared the sensitivity of the cell lines used in polio laboratory simultaneously to standard poliovirus and Oral Polio Vaccine (OPV) polioviruses, to ensure the accurate detection of circulating and imported polioviruses in the society. Materials and Methods: Cell sensitivity test was performed according to the World Health Organization (WHO), Polio Laboratory Manual for RD, L20B and Hep2 cell lines using 3 serotypes of standard monovalent and OPV polioviruses. The test was repeated every four passages for all cell lines. Results: The sensitivity of L20B and Hep2 cell lines for standard poliovirus type 1 and 2 is more than sensitivity for the same types of OPV virus but for poliovirus type 3 it is vice versa. Also RD cell line is more sensitive to all 3 types of OPV virus. In addition, the test showed that increasing the passage number will decrease the sensitivity of all cell lines. Conclusion: Using RD & L20B cell lines simultaneously (with low passage number) will assure us of sensitivity and accuracy of the cell lines for detection of circulating and imported polioviruses.

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      The doctrine of “Loss of Chance” recovers damages that occur as a result of destruction of prospect for achieving a favorable outcome. The outcome might have been acquiring benefits or preventing harms. There is no consensus among jurisdictions about the entitlement of the losers of such chances (chances to acquire benefits or to prevent harms) for compensation. Some European countries, such as France, have strongly supported the doctrine, whereas some other jurisdictions in the North American region, such as South Dakota State, have prevented the doctrine from any further expansion using statutory interventions. This article reviews the current application of the doctrine of “Loss of Chance” in the European and the American jurisdictions. It also examines the applicability of this doctrine in the Iranian legal system. Although neither relevant statutes nor jurisprudences have recognized the doctrine of “Loss of Chance” in Iran, the underlying principles of the Iran’s tort law and Sharia may imply its applicability. However, regardless of the legal grounds, some procedural and enforcement barriers may prevent this doctrine from being invoked in Iran.           

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In this article microhexapod robot is introduced as a micromanipulator. First hexapod which is a parallel mechanism is investigated and also modifications that is needed for the improvement of positioning accuracy and eliminating factors such as clearance and friction in the conventional joints. Doing this, spherical and universal joints are replaced with flexural beam type joints after scaling down the hexapod. Then the degrees of freedom of flexure joints are achieved and after that the instantaneous center of rotation of flexure joints is derived for every finite twist of moving platform and it is shown that the kinematic chain of each pod of microhexapod consists of two spherical joints and a prismatic actuator; but it differs from hexapod in a way the location of the instantaneous center changes with the change of the finite twist of moving platform. Thereafter the velocity kinematics of microhexapod is solved using screw theory. In addition, using the analytical formula, the velocity of actuators was calculated for some case studies; linear motion of moving platform with constant velocity and also constant acceleration and also movement with constant velocity in a circular path. The results are verified with the finite element analysis and shown good agreement.

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Computer-aided process planning (CAPP) is a bridge for integrating computer-aided design (CAD) and computer-aided manufacturing (CAM). One of the basic computer-aided process planning tasks is sequencing of machining features. Sequencing of machining features is determined based on technical and geometrical rules. In this paper, the technical rules, geometrical rules and sequencing of machining features method were discussed. At first, some of the technical rules were pointed. Then, the geometrical interactions were studied and two new geometrical rules were introduced for sequencing the machining features having geometrical interaction. These rules can yield unique results and they are identified easily by the computer systems. Also, an algorithm was introduced for automated application of these geometrical rules in computer systems. The conflict between the technical and geometrical rules that may occur in some cases was studied. This conflict must be considered in the sequencing of machining features methods. Finally, an algorithm was introduced for sequencing of machining features based on permutation. In this algorithm the technical and geometric rules were applied separately and step by step. If there is any conflict between technical and geometrical rules, this conflict could detect automatically in this algorithm. Algorithms were programmed and verified in PythonOCC.

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In multi-pass groove welding, residual stress distribution, value and associated distortion are dependent on several factors, including the welding process-dependent parameters, mechanical properties of materials and fixtures. In present study, temperature distribution of three welding processes with different geometric designs are registered by the K type thermocouple. Each of the samples contains the same thickness of stainless steel plate A316 that was welded based on welding procedure specification with gas tungsten arc welding method with groove corner joints single bevel without gap and bevel face, single and double bevel with gap and bevel face. Created residual stress on a sample was initially measured by nondestructive ultrasonic transverse waves method. After cutting the vertical part (plate without Groove), for hole drilling device installation purposes, aforementioned stress was measured by the semi-destructive hole drilling method. While for two other geometrical designs only ultrasonic method has been used to prevent parts destruction. All three aformentioned designs were modeled in Simufact.welding finite element code (FE) and results were compared with experimental temperature and residual stress measurements. The comparison shows that experimental measurements and numerical values match well with each other highlighting a reasonable validation of finite element models resutls. Current research results show that changing the geometry of the weld configuration have a significant effect on changes in the distribution and maximum value of transvers residual stress, but trivial influence on maximum longitudinal residual stress.

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