690 research outputs found

    Quality measurement indicators for Iranian Health Centers

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    Background: Recently, quality is a serious concern in development of organizations. There are various indicators to assess quality and the purpose of this study was to identify the main indicators for quality measurement of Iranian health centers. Methods: This qualitative study was conducted in three stages: first, review of the literature was performed to identify different indicators for quality measurement in health centers; second, a two-round Delphi process was used with participation of 18 experts in both rounds; third, Analytical Hierarchy Process (AHP) method was applied to give weights to each indicator. Results: Twenty-seven indicators were identified from the literature review stage. The Delphi method reduced the list to 4 indicators. Developing a quality plan in the health center had the highest weight (38) and percentage of followed complaints the lowest (12). The consistency rate was 7.2 indicating appropriateness of the data. Conclusion: This list of indicators can be used as a template for measuring quality of health centers in Iran and possibly in other developing countries

    Common Ownership: Do Managers Really Compete Less?

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    This Article addresses an important question in modern antitrust: when large investment funds have holdings across an industry, is competition depressed? The question of the impact of common ownership on competition has gained much attention as the role of institutional shareholding has grown, with the funds of the three largest management companies holding in aggregate approximately 21% of the shares of a typical S&P 500 firm. It is a source of acute disagreement among scholars and policymakers, with some who believe common ownership does depress competition seeking antitrust law reforms that would significantly constrain how investment funds operate. Neglected in this vigorous debate, however, is a careful analysis of how the persons who in the first instance actually make the decisions that determine an industry’s competitiveness – firm managers – would act differently in the presence of common ownership. In essence, even if the common owners were to pressure firms to compete less, how, if at all, would that change the structure of incentives within which these managers work? The forces that shape managerial decision-making at publicly traded firms have been the object of intense study by scholars of corporate governance for decades, primarily through use of managerial agency cost analysis. The question of how the dynamics among firms in a concentrated industry affect its level of competition has been subject to similarly intense scrutiny by industrial organization economists. We use learning from both of these fields to conclude that, at current levels, common ownership is unlikely to have a meaningful effect on the managerial structure of incentives in ways that the industrial organization theories suggest would affect competition. This conclusion thus cautions against the proposed antitrust reforms, which would solve a non-problem while adding to the costs of the investment vehicles of choice for tens of millions of ordinary Americans

    Thermodynamic evaluation of a combined-cycle power plant with MSF and MED desalination

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    Rising water scarcity and abundant brine water resources, especially in desert locations, call for the wider adaptation of desalination techniques. Furthermore, the interdependency of water and energy has gained more attention in recent years and it is expected to play an important role in the near future. The present study deals with both topics in that it presents the coupling of a power plant with desalination units for the simultaneous generation of energy and water in Iran. The power plant used in the analysis is the Qom combined-cycle power plant. The plant is integrated, first, with a multi-stage flash (MSF) unit and, then, with a multi-effect desalination (MED) unit, and it is evaluated using energy and exergy analyses. We find that the generated power of the integrated systems is decreased by 9.7% and 8.5% with the MED and the MSF units, respectively. Lastly, the freshwater production in the plant using MED is significantly higher than in the plant with MSF (1,000 versus 1,521 kg/s).Fontina Petrakopoulou would like to thank the Universidad Carlos III de Madrid and the Ministerio de Economía, Industria y Competitividad (Ramón y Cajal Programme RYC-2016-20971) for their financial support of this study

    Exergoeconomic modeling and evaluation of a combined-cycle plant with MSF and MED desalination

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    In the coming years, numerous regions are expected to suffer from water scarcity. One of the technologies of great interest in facing this challenge has been the generation of freshwater through water desalination, a process that reduces the amount of salt and minerals to a standard level, making the water suitable for drinking or agricultural/industrial use. The efficiency of each desalination process depends on the concentration of salts in the raw water and the end-use of the produced water. The present study presents the exergetic and exergoeconomic analyses of the coupling of a power plant with desalination units for the simultaneous generation of energy and water in Iran. The plant is integrated, first, with a multi-stage flash (MSF) unit and, then, with a multi-effect desalination (MED) unit. We find that the cost of exergy destruction of the MED and MSF integrated plants is lower when compared to the standalone power plant by about 0.1% and 9.2%, respectively. Lastly, the freshwater production in the plant using MED is significantly higher than that in the plant with MSF (1,000 versus 1,521 kg/s).Khoshgoftar Manesh, M. H., Kabiri, S., Yazdi, M., & Petrakopoulou, F. (2020a). Exergoeconomic modeling and evaluation of a combined-cycle plant with MSF and MED desalination. Journal of Water Reuse and Desalination, 10(2), 158-172

    Influence of Al2O3 reinforcement on precipitation kinetic of Cu-Cr nanocomposite

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    In this paper, the kinetic of precipitation process in mechanically alloyed Cu-1 wt.% Cr and Cu-1 wt.% Cr/3 wt.% Al2O3 solid solution was compared using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The ageing kinetics in Cu¿Cr and Cu¿Cr/Al2O3 can be described using Johnson¿Mehl¿Avrami (JMA) and Sestak¿Berggren (SB) models, respectively. These different behaviors have been discussed in details. It was found that in presence of Al2O3 reinforcement, the ageing activation energy is decreased and the overall ageing process is accelerated. This behavior is probably due to higher dislocation density previously obtained during ball milling and Al2O3¿Cu interface. TEM observations confirm that Al2O3¿Cu interface and structural defects act as a primary and secondary nucleation sites, respectively.Gobierno de España ENE 2007-67926-C02-0

    Marine energy extraction of waves and tidal currents in Chabahar Bay

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    Development of modern energies is one of the most important issues that all countries have focused on and have tried to find a new model in that respect. This study investigates various methods of estimating energies that are produced by wave and then it concludes that the best method is spectrum analysis using Fourier analysis. Using available data of year 1998 in Chabahar and applying a program which is produced in MATLAB environment, rate of producible energy in year 1998 is equal to 6.9 Kwh/m² and producible power of waves has been estimated to be 3.9 Kw/m² with the lowest rate of energy observed in winter and the highest rate of wave energy in summer. Probable cause of this phenomenon could be seasonal winds that blow in summer. According to the flowmetry report done by Ports and Maritime Organization in Chabahar, in Aw1 Station has divided its 9-meter distance below water surface into 7 cells, therefore, with considering 1×1m channels and assuming that flow in each channel has been changed steadily, tide flow energy has been estimated and average energy of Chabahar station has been obtained equal to 0.12 w/m^2 within two weeks. In the second way, using program written in MATLAB environment and calculating the surface under the chart, tide energy has been calculated equal to 0.19w/ m^2. According to the obtained results, producible energy of tidal current in Chabahar Gulf is very low and it is not economical

    Golpayegan metamorphic complex (Sanandaj–Sirjan Zone, Iran) as evidence for Cadomian back-arc magmatism: structure, geochemistry and isotopic data

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    The Golpayegan metamorphic complex is located in the Sanandaj-Sirjan Zone, Iran. This complex consists of various metamorphic rocks including schists, marbles, slates, gneisses, and amphibolites, most of them have Neoproterozoic age. The presence of structures such as sigma fabrics, boudinage, folded boudinage and interfering fold patterns indicates the occurrence of more than two deformation phases in the Golpayegan metamorphic complex. The measurement of strain intensity in the folds indicated deep immersion of structures and old Precambrian settings that had been influenced by orogenic events in the Neoproterozoic. These deformed rocks were exposed during extensional movements and, subsequently, sheared. The results based on field works shown geochemical relations and initial εNd(600 Ma) values of amphibolites in three sampling points located in Golpayegan region manifested that the protolith of the first (a') and second (b') sampling points had mantle origin (ortho-amphibolite), whilst protolith of the third (c') sampling point had sedimentary origin (para-amphibolite). Geochemically, the Golpayegan ortho-amphibolites showed subalkaline basalt-basaltic andesite compositions of tholeiitic affinity. The negative anomalies of Nb and Ti relative to Pb, La, and Ce in the primitive mantle-normalized spider-diagram and εNd(600 Ma) values revealed the subduction environment for ortho-amphibolites. The ortho-amphibolites exhibited the intermediate chemistry between the normal mid-ocean ridge basalt and island-arc tholeiitic basalt. Enrichment in large ion lithophile elements (LILE), light rare earth elements (LREE), and relative depletion in high field strength elements (HFSE) suggest the back-arc basin setting for the Golpayegan ortho-amphibolites. The primitive magma of the ortho-amphibolites was produced by 8–20% melting of spinel lherzolite. According to the Neoproterozoic age of the Golpayegan ortho-amphibolites and their relationship with the Golpayegan granitic gneiss (596‒578 Ma), it shows that they can be related to the Cadomian back-arc basin in the north of Peri-Gondwana at the Neoproterozoic. The high values of 87Sr/86Sr (0.708450‒0.714986) interpreted as result of seawater hydrothermal alteration.publishe
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