59 research outputs found

    A perspective analysis about the effects of dams - Evidence from Iran

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    The construction of dams is one of the main mechanisms undertaken by policy makers for managing the challenge of water scarcity in recent decades, but this strategy can lead to negative social, economic and environmental consequences. The purpose of this study was to investigate a perspective analysis about the effects of construction of the dam on the Sirvan River in Iran. A sample of 273 rural households was selected using Cochran’s formula by use of multi stage sampling technique. In the mentioned villages, 36 key-informants were selected and interviewed. The results showed that the residents of rural areas were dissatisfied with the construction of the dam. Daryan dam construction in the region, in the social dimension, reduced the components of social capital by nearly 20%; in the economic dimension, reduced the economic components by nearly 24%; but in the infrastructure dimension, has improved the infrastructure of rural areas by only 4%. The results of t-test also show that the effect of dam construction in both economic and social dimensions was significant from the viewpoint of villagers and key-informants. The research results show significant negative effects of dam construction on social capital, trust and social participation. The viewpoint of villagers and key informants Daryan dam construction reduced the area under cultivation and production of the villagers of the region. However, in terms of infrastructure indicators, it has not been able to create positive and significant effects on the well-being of the villagers in the region

    Relationship Between Air-Blowing Duration and Bond Strengths of Three Adhesive Systems to Dentin After Thermal Aging

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    The purpose was to evaluate the effect of air-blowing duration of three different adhesive systems on immediate or thermal aged resin-dentin shear bond strength (SBS). Human dentin surfaces were bonded with: one-step (Bond Force, BF), two-step (FL-Bond II, FLB) and three-step (Scotch Bond Multi-Purpose, SBMP) adhesive systems. Bonded surfaces from each group were air-blown for 0, 5, or 10 s and cured. Composite cylinders were built on the treated surfaces and cured. Half of the specimens from each group were tested immediately and the other halves were tested after thermal aging. Statistical analysis showed signifcant decrease in SBS after thermal aging compared to immediate testing in all groups, except BF after 5 s air-blowing or FLB and SBMP with no air-blowing (p\u3e0.05). The results suggested that 5 s air-blowing is necessary to obtain a stable SBS for BF. However, extended airblowing duration of FLB and SBMP decreased the SBS significantly after thermal aging

    Contradiction of Opportunity/Challenge Development: Sustainable Management of Water Resources in Kurdistan Province in Institutional and Public Conflicts

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    The present research, by problematizing the water crisis in Iran and Kurdistan province, has tried to analyze the situation of institutional and public water transfer disputes as a solution to this crisis. In this regard,  the question of whether the transfer of water in the province has provided an opportunity for its development or if it has led to development bottlenecks, analyzing the debates and controversies of two institutional perspectives in the form of experts and managers of the regional water company of the province has been raised. Kurdistan and civil and environmental activists are concerned about the transfer of water from the west to the east of the province. Therefore, the sustainable development approach, which seeks the connection and interaction of the three spheres of society, economy and environment, has formed the theoretical basis of this research. The methodology is based on theoretical and experimental goals and position, while institutional ethnography is based on the experiences, knowledge, views of the interviewees [31 semi-structured interviews], and the review of statistics and documents related to the discussion of water, and its leading crisis has been water transfer in Kurdistan province. According to the analysis of 6 secondary categories, the results show that managers and experts consider climate change and natural obstacles to water exploitation as the basis of many conditions and obstacles to sustainable management of water resources, while activists focus on the weakness of sustainable management of water resources. They also emphasize, managers and institutional experts highlight the lack of integrated water management and the lack of funds as the basis of institutional weakness and the indifference of the academic elite and provincial representatives to the water issue, and the lack of bargaining power in allocating water to the province. They consider political issues and lack of public participation as the reason for this. And finally, it can be concluded that water transfer is not considered an opportunity but a bottleneck and challenge for the province's development

    The Role of N-Acetylcysteine in Platelet Aggregation and Reperfusion Injury in Recent Years

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    Introduction: N-acetylcysteine (NAC) is an amino acid that contains a cysteine group and is currently used widely in various fields of medical research especially in cardiology. In this review, potential benefits of NAC in the aggregation of platelet and reperfusion injury are evaluated. Methods and Results: The available evidence was collected by searching Scopus, Pub-Med, Medline, Cochrane central register of controlled trials, and Cochrane database systematic reviews. Our searching was performed without time limitation and only English language articles were included in this review. Key words used as search terms included “N-acetylcysteine”, “platelet aggregation”, “reperfusion injury”. Over the past decade, several investigations were carried out to ascertain reperfusion injury and antiplatelet properties of NAC, and in this article the results of investigations in both models (human and animal) were addressed in details. The results revealed that NAC has an important antiplatelet property in animal models while this effect is not very significant in human models and needs more investigations. However, its reperfusion injury in both models is worth noticing. Conclusions: Due to the limited data about effectiveness of NAC in both human and animal as antiplatelet agent, more investigation is needed to evaluate NAC efficacy in platelet aggregation and reperfusion injury especially in human studies in the future

    Deciphering the binding mode of dinitramine herbicide to ct-DNA, a thermodynamic discussion

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    Dinitramine is a herbicide that has been used to control annual grasses and broadleaf weeds in cotton and soybeans in Iran. In this study, the electrochemical behavior of dinitramine was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The interaction of dinitramine with ct-DNA was evaluated by CV, competitive fluorescence, UV-Vis spectroscopy, FT-IR spectroscopy, and viscosity titration. In addition, the thermodynamic parameters of DIN�DNA complex were calculated by spectrophotometric titration. The values of �Hbin., �Sbin., and �Gbin. (T = 290.65 K) of the DIN�DNA complex were +39.25 kJ mol�1, +215.71 J mol�1, and �23.45 KJ mol�1, respectively. These data revealed that the endothermic binding has its origin in the hydrophobic interactions. Also the high positive �Sbin was explained according to the DIN structure that optimized by mechanical quantum calculations. However, all data showed that the major groove binding between DIN and ct-DNA is more predominant than other binding modes. © 2015 Taylor & Francis

    Study on Free Vibration and Wave Power Reflection in Functionally Graded Rectangular Plates using Wave Propagation Approach

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    In this paper, the wave propagation approach is presented to analyze the vibration and wave power reflection in FG rectangular plates based on the first order shear deformation plate theory. The wave propagation is one of the useful methods for analyzing the vibration of structures. This method gives the reflection and propagation matrices that are valuable for the analysis of mechanical energy transmission in devices.  It is assumed that the plate has two opposite edges simply supported while the other two edges may be simply supported or clamped. It is the first time that the wave propagation method is used for functionally graded plates. In this study, firstly, the matrices of reflection and propagation are derived. Second, these matrices are combined to provide an exact method for obtaining the natural frequencies. It is observed that the obtained results of the wave propagation method are in a good agreement with the obtained values in literature. At the end, the behavior of reflection coefficients for FG plates are studied for the first time

    A finite element model for the thermo-elastic analysis of functionally graded porous nanobeams

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    In this study, for the first time, a nonlocal finite element model is proposed to analyse thermo-elastic behaviour of imperfect functionally graded porous nanobeams (P-FG) on the basis of nonlocal elasticity theory and employing a double-parameter elastic foundation. Temperature-dependent material properties are considered for the P-FG nanobeam, which are assumed to change continuously through the thickness based on the power-law form. The size effects are incorporated in the framework of the nonlocal elasticity theory of Eringen. The equations of motion are achieved based on first-order shear deformation beam theory through Hamilton's principle. Based on the obtained numerical results, it is observed that the proposed beam element can provide accurate buckling and frequency results for the P-FG nanobeams as compared with some benchmark results in the literature. The detailed variational and finite element procedure are presented and numerical examinations are performed. A parametric study is performed to investigate the influence of several parameters such as porosity volume fraction, porosity distribution, thermal loading, material graduation, nonlocal parameter, slenderness ratio and elastic foundation stiffness on the critical buckling temperature and the nondimensional fundamental frequencies of the P-FG nanobeams. Based on the results of this study, a porous FG nanobeam has a higher thermal buckling resistance and natural frequency compared to a perfect FG nanobeam. Also, uniform distributions of porosity result in greater critical buckling temperatures and vibration frequencies, in comparison with functional distributions of porosities

    Application of chaotic attractor analysis in crack assessment of plates

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    Part-through crack presence with limited length is one of the prevalent defects in plate structures. However, this type of damage has only a slight effect on the dynamic response of the structures. In this paper the modified line spring method (MLSM) is used to develop a nonlinear multi-degree of freedom model of part through cracked rectangular plate and chaotic interrogation is implemented to assess crack-induced degradation in the nonlinear model. After a convergence study of the proposed model in time series domain in which the plate subjected to Lorenz-type chaotic excitation, the tuning of interrogation is conducted by crossing the Lyapunov exponents’ spectrums of the nonlinear model of the plate and chaotic signal. In this research nonlinear prediction error (NPE) is proposed as a damage sensitive feature which deals with the chaotic attractor of the excited system response. It is found that there are ranges of tuning parameter that result in higher damage sensitivity of the NPE. Damage characteristics such as: length, angle, location and depth of crack are considered as parameters to be varied to scrutinize the response of the plates. Results show that NPE generally has significantly higher sensitivity in comparison with conventional frequency-based methods; however this property has different levels for various boundary conditions. Keywords: Crack, Chaotic, Nonlinear dynamics, Plate, Prediction error, Structural health monitorin

    Providing evidence for use of Echinacea supplements in Hajj pilgrims for management of respiratory tract infections

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    Objective: To evaluate potential applicability of Echinacea use for management of respiratory tract infections in Hajj travelers. Method: The PubMed database was explored with Mesh terms "Echinacea" and "Respiratory Tract Infections". Results: A hundred journal articles were yielded but only 66 most relevant ones used for the review. Conclusion: There is a considerable amount of evidence that shows effectiveness of Echinacea products in prevention and treatment of respiratory tract infections in this setting. Although there are some controversial findings, utilization of standardized products with adequate dose or combinations with other immune-stimulants in controlled and well-designed trials will be highly encouraging. © 2016 Elsevier Ltd

    Critical ethnography of Self-governing policy in Rural Production Cooperatives (Case Study: Rural Production Cooperatives in Kurdistan Province)

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    In the last few decades, along with the wave of structural adjustment and privatization of neoliberal policies of the ninth government in Iran, one of the policies and strategies in the field of agricultural development and its related cooperatives was self-regulation. The purpose of these policies has been announced in the institutional texts, statutes and organizational rules and regulations, reducing the government's role, increasing the participation and decision-making power of the local community, and empowering the production cooperatives. The purpose of this research is to study the consequences of this policy in rural production cooperatives in Kurdistan province. On this issue, the present study deals with theoretical and conceptual support of neoliberalism in the field of economics and management and the methodology of the Institute of Ethnography of Dorothy Smith to discuss the present subject. In this research, a critique of the autonomy of the production cooperatives is discussed in order to identify the policy of self-regulation. Then, using the temporal analysis, the interviewed interviewer's experience (the components of production co-operatives: CEO, board and member farmers) is discussed. The number of interviewees in this study was based on the theoretical saturation technique of 34 people, with all of them having a deep and semi-structured interview. The results of this research indicate that rural production cooperatives in Kurdistan province, in addition to social, cultural and managerial problems and after the implementation of self-regulation policy, have been involved with other problems caused by self-regulation shock, self-governing autonomy and abolition of state support
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