39 research outputs found

    Generalized Super Efficiency Model for Ranking Efficient Decision Making Units in Data Envelopment Analysis

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    Abstract: In evaluating decision making units (DMU's) by using Data Envelopment Analysis (DEA) technique, we encounter the situation in which more than one unit takes efficiency score of one. In such a case, some criteria should be considered to rank the DMU's. Some efficient techniques such as AP, MAJ,etc may be used in this way. For some sets of data, with special structure in models that above mentioned, may be infeasible and unstable. In this paper, a new model is developed that all the existing drawbacks of previously applied models remove. Some numerical examples are put forward

    Trace metal distribution in the bed, bank and suspended sediment of the Ravensbourne River and its implication for sediment monitoring in an urban river

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    Purpose This study aims to identify a suitable sediment compartment for sediment quality monitoring by: (a) studying the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the bed, bank and suspended sediment compartments of the Ravensbourne River to establish any differences in trace metal concentrations with compartment; (b) determining the influence of sediment particle size fractions ( 0.05) in the concentrations of metals between the suspended sediment and the < 63 μm bed sediment fraction, but there was a significant difference (p < 0.05) between the suspended sediment and the < 63 μm bank sediment fraction. There were also significant differences between the concentrations of metals in the < 63 μm and the 63 μm–2 mm fractions. Generally, the Ravensbourne River did not comply with the draft UK sediment quality guidelines for the metals analysed. Conclusions This study shows the importance of identifying a suitable sediment compartment to sample for compliance with sediment quality standards. The bed and suspended sediments are the most widely used sediment compartments for sediment monitoring, but collecting sufficient mass of the < 63 μm sediment fraction for monitoring presents a challenge for urban gravel bed rivers like the Ravensbourne River. It seems appropriate to establish individual monitoring regimes for different rivers

    Effect of GnRH on guinea pig endometrium at preimplantation stage

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    242-246Endometrium of GnRH treated group resembled with pregnant group and endometrial thickness in these groups significantly increased in comparison with non-pregnant group. In GnRH treated animals, most of histomorphological changes in epithelial cells, glands and stroma of uterus was similar to pregnant group. The results revealed that mammalian form of GnRH exerted endometrial change in guinea pig almost similar to those occur in normal pregnant animals and its administration prior to implantation may improve pregnancy rate following embryo transfer

    Late Holocene relative sea-level fluctuations and crustal mobility at Bataneh (Najirum) archaeological site, Persian Gulf, Iran

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    The impacts of relative sea-level (RSL) variations and crust mobility on the development of ancient harbours in the northern Persian Gulf are poorly understood. Many unanswered questions remain with regard to the main reasons for a shift in the location of the most important ancient harbours in the northern part of the Persian Gulf coastal since 50 BC. Furthermore, some important early Islamic harbours, such as Siraf, have ancient city quarters that are today below the present sea level. The aim of this study is to evaluate the relationship between halokinesis and RSL changes using geophysical models and multidisciplinary geoarchaeological methods at the ancient Sassanid–Islamic site of Bataneh (presently known as Najirum) located at the foothill of an active Darang salt diapir. The results reveal that&nbsp;after the mid-Holocene highstand, RSL regression was not continuous. The studied facies have recorded three RSL oscillations. The oscillations are correlated with the eustatic sea-level position. During the first lowstand, important Sassanid harbours shifted from Rishar to Apologus. The second lowstand is consistent with the transition of maritime trade from Apologus to Siraf, during the Abbasid dynasty. Uplift of the Bataneh coastal zone exposed the city to risks from flooding and fluvial debris flows. With a modification of the local watershed, runoff water originating from the salt anticlinal was controlled and used for the extraction of gypsum in evaporation ponds. The economic expansion of Siraf led to Bataneh being abandoned with a shift in trade to Kish Island
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