2,415 research outputs found

    Multi-objective green supply chain optimization with a new hybrid memetic algorithm using the Taguchi method

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    AbstractThe aim of most supply chain optimization problems is to minimize the total cost of the supply chain. However, since environmental protection is of concern to the public, a green supply chain, because of its minimum effect on nature, has been seriously considered as a solution to this concern. This paper addresses the modeling and solving of a supply chain design for annual cost minimization, while considering environmental effects. This paper considers the cost elements of the supply chain, such as transportation, holding and backorder costs, and also, the environmental effect components of the supply chain, such as the amount of NO2, CO and volatile organic particles produced by facilities and transportation in the supply chain. Considering these two components (cost and environmental effects), we propose a multi-objective optimization problem. In this model, the facilities and transportation options have a capacity constraint and, at each level of the chain, we have several transportation options with different costs. We utilize a memetic algorithm in combination with the Taguchi method to solve this complex model. We also propose a novel decoding method and priority based algorithm for coding the solution chromosome. The performance of the proposed solution method has been examined against the hybrid genetic Taguchi algorithm (GATA) on a set of numeric instances, and results indicate that the proposed method can effectively provide better results than previous solution procedures

    DC-SIMD: dynamic communication for SIMD processors

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    SIMD (single instruction multiple data)-type processors have been found very efficient in image processing applications, because their repetitive structure is able to exploit the huge amount of data-level parallelism in pixel-type operations, operating at a relatively low energy consumption rate. However, current SIMD architectures lack support for dynamic communication between processing elements, which is needed to efficiently map a set of non-linear algorithms. An architecture for dynamic communication support has been proposed, but this architecture needs large amounts of buffering to function properly. In this paper, three architectures supporting dynamic communication without the need of large amounts of buffering are presented, requiring 98% less buffer space. Cycle-true communication architecture simulators have been developed to accurately predict the performance of the different architectures. Simulations with several test algorithms have shown a performance improvement of up to 5x compared to a locally connected SIMD-processor. Also, detailed area models have been developed, estimating the three proposed architectures to have an area overhead of 30-70% compared to a locally connected SIMD architecture (like the IMAP). When memory is taken into account as well, the overhead is estimated to be 13-28%

    Reproductive biology of Indian squid, Uroteuthis duvauceli (Orbigny, 1835), in the northern Gulf of Oman

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    Some aspects of the reproductive biology of the Indian squid, Uroteuthis duvauceli, were studied from June 2006 to May 2007. A total of 1200 specimens were collected from approximately 30-80m depths by trawling in 50 stations, of which 360 samples were studied for sex determination and fecundity. The minimum and maximum total and mantle length, and body weight were recorded in December and June, respectively. The highest range of total length (410-420mm), mantle length (150-160mm) and body weight (90-100g) were encountered in September. The specimens were composed of 34% male and 66% female (M:F=1:2). This species was found to be more abundant in summer. The minimum and maximum ovary weights were 2.1g and 7.9g with an average of 4.9g, respectively. These values for nidamental gland weight were 0.70 and 2.61g with an average of 1.6g. The minimum and maximum absolute fecundity were 25510 (in August) and 375600 (in April), respectively. These values for relative fecundity were 5207 (in April) and 867 (in August), respectively. The highest gonadosomatic index (GSI) was in April (14.38) and the lowest was in July (8.63). This squid is, therefore, assumed to be a spring spawner. Minimum and maximum egg diameter were 0.72mm (in August) and 2.5mm (in April), respectively

    Evaluation of ecological status of the Persian Gulf inshore waters (Hormozgan rocky bottoms) using macrophytic communities and a macroalgae biological index, EEI

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    Marine benthic macrophytes (seaweed and seagrasses) are key structural and functional components of some of the most productive ecosystems of the world. They absorb nutrients through their surface directly from the marine environment and thus they are very important biological elements for the estimation of ecological status, representing reliable indicators of coastal waters. The aim of this study was to assess the ecological status and trophic level of Hormozgan rocky bottoms according to Ecological Evaluation Index (EEI). Sampling was done bi-monthly at seven stations at the intertidal rocky shores, west of Hormozgan Province. In this study a total of 63 species were identified, of which 15 species from seven genera belonged to green algae; 16 species from five genera belonged to brown algae; and 32 species from nine genera belonged to red algae. Coverage data of macroalgae and EEI indicate a high level of eutrophication for Saieh khosh, and Bostaneh. They are classified as zones with bad and poor ecological status, respectively. Also it has been proved that concentrations of biogenic elements and phytoplankton blooming are higher in these zones. The best values of the estimated metrics at Tahooneh and Michaeil could be explained with the good ecological conditions in those zones and the absence of pollution sources close to those transects. The values of abundance of macroalgae and EEI indicate moderate ecological conditions for Koohin, Lengeh and Chirooieh

    Hydrogel nanoparticle encapsulated plasmid as a suitable gene delivery system

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    To facilitate the delivery of genetic material, the use of appropriate carriers such as polymers is necessary. Nanoparticles comprising of chitosan-alginate polymers were formed through pregel preparation method. Chi/Alg nanoparticles had a mean Z-Average diameter of 161.8 nm and mean zeta 29.3 mV, respectively. The ability of plasmid-complex in preventing DNA migration showed Chi/Alg nanoparticles have great capacity to maintain plasmid. The efficiency of nanoparticles for transfection of pEGFP-N1 plasmid in the cultured HEK 293 cells was measured by flow cytometry. Cell viability assays indicated that nanoparticles had no toxic effect on HEK 293 cells after 4 or 24 h. Our suitable candidate for gene delivery would be alg/chi nanoparticles.Для облегчения доставки генетического материала необходимо использование подходящих носителей, таких как полимеры. Наночастицы, состоящие из хитозан-альгинатных полимеров, были получены методом подготовки прегеля. Chi/Alg наночастицы имели средний диаметр 161.8 нм (Z-Average) и средний zeta-потенциал 29.3 mV. Отсутствие миграции ДНК во время электрофореза комплексов плазмиды с наночастицами показало, что Chi/Alg наночастицы могут удерживать плазмидную ДНК внутри комплекса. Эффективность наночастиц для трансфекции плазмиды pEGFP-N1 в культивируемые клетки HEK 293 была измерена с помощью жидкостной цитометрии. Тесты на жизнеспособ-ность клеток показали, что наночастицы не имели токсичного эффекта на клетки HEK 293 через 4 ч или 24 ч. Наночастицы Alg/Chi являются подходящим кандидатом для доставки генов

    Immunization with Bivalent Flagellin Protects Mice against Fatal Pseudomonas aeruginosa Pneumonia

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    Pseudomonas aeruginosa lung infections present a major challenge to healthcare systems worldwide because they are commonly associated with high morbidity and mortality. Here, we demonstrate the protective efficacy of type a and b flagellins (bivalent flagellin) against acute fatal pneumonia in mice. Mice immunized intranasally with a bivalent flagellin vaccine were challenged by different flagellated strains of P. aeruginosa in an acute pneumonia model. Besides the protective effect of the vaccine, we further measured the host innate and cellular immunity responses. The immunized mice in our study were protected against both strains. Remarkably, active immunization with type a or b flagellin significantly improved survival of mice against heterologous strain compared to flagellin a or b antisera. We also showed that after an intranasal challenge by P. aeruginosa strain, neutrophils are recruited to the airways of vaccinated mice, and that the bivalent flagellin vaccine was proved to be protective by the generated CD4+IL-17+ Th17 cells. In conclusion, bivalent flagellin vaccine can confer protection against different strains of P. aeruginosa in an acute pneumonia mouse model by eliciting effective cellular and humoral immune responses, including increased IL-17 production and improved opsonophagocytic killing

    Microstructure, texture and tensile properties of ultrafine/nano grained magnesium alloy processed by accumulative back extrusion

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    An AZ31 wrought magnesium alloy was processed by employing multipass accumulative back extrusion process. The obtained microstructure, texture and room temperature tensile properties were characterized and discussed. Ultrafine grained microstructure including nano grains were developed, where the obtained mean grain size was decreased from 8 to 0.5 µm by applying consecutive passes. The frequency of both low angle and high angle boundaries increased after processing. Strength of the experimental alloy was decreased after processing, which was attributed to the obtained texture involving the major component lying inclined to the deformation axis. Both the uniform and post uniform elongations of the processed materials were increased after processing, where a total elongation of 68 pct was obtained after six-pass deformation. The contribution of different twinning and slip mechanism was described by calculating corresponding Schmid factors. The operation of prismatic slip was considered as the major deformation contributor. The significant increase in post uniform deformation of the processed material was discussed relying on the occurrence of grain boundary sliding associated with the operation of prismatic slip.Postprint (author's final draft

    Accessing the Longitudinally Polarized Photon Content of the Proton

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    We investigate the QED Compton process (QEDCS) in longitudinally polarized lepton-proton scattering both in the elastic and inelastic channels and show that the cross section can be expressed in terms of the polarized equivalent photon distribution of the proton. We provide the necessary kinematical constraints to extract the polarized photon content of the proton using this process at HERMES, COMPASS and eRHIC. We also discuss the suppression of the major background process coming from virtual Compton scattering. We point out that such an experiment can give valuable information on g1(xB,Q2)g_1(x_B, Q^2) in the small xBx_B, broad Q2Q^2 region at the future polarized collider eRHIC and especially in the lower Q2Q^2, medium xBx_B region in fixed target experiments.Comment: Version to appear in PR
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