574 research outputs found

    Recognizing greenway network for quantifying students experience on campus-based universities : assessing the campus outdoor spaces at San Diego State University

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    This paper evaluates the potential of creating a green infrastructure – more specifically, an urban greenway – and its contribution the students’ campus experience, with emphasis on the outdoor university activities. To achieve best value for money – particularly in the current financial climate, with severe budget cuts constraining universities – justifying investments on campus outdoor spaces such as greenways, relies on a clear demonstration of their link to the overall success of the campus. Attempts of quantify the benefits from investments on such spaces are challenged by the scarcity of studies on the relationship between students’ experience and design (and related cost) of different types of campus landscape settings. This paper fills this gap by offering a thorough examination of a variety of extant campus developments and by measuring the performance of some selected open spaces against a ‘price-tag’ mechanism. The case study of the San Diego State University has been chosen as core case study and supplemented by 16 sub-cases across California State. The assessment has been conducted through three steps. First, a site inventory of the physical characteristics and landscape features has been conducted, focusing on 7 typologies of campus outdoor spaces (COS). Second, four main use patterns (Individual-customized, Group-social, Programmed-scheduled, and Active experiences) have been assessed by calculating the intensity of use (function of the frequency and duration of use) for each of them. The data collected was based on syntax observation methods with photos and maps of COS as prompts. Third, a Campus-Experience-Score (C-E-C) has been calculated and normalized to the size and population of the university, matching it against the actual development costs of each COS setting. The C-E-C allows measuring the link between types and features of COS and related students’ experience. Findings were discussed and verified through six in-depth interviews with local and international academics and developers/practitioners. This paper offers valuable benchmark to designers and planners seeking to maximize the value for money of investments on COS such as greenways

    Nonlinear Seismic Analysis of Building - Foundation Soil Systems

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    This paper deals with the problem of nonlinear seismic analysis of building - foundation soil systems. The building considered is modeled as a shear - type building supported on the surface of homogeneous isotropic elastic half-space. The governing nonlinear equations of motion for the structure - soil system are solved in the time domain using the step-by-step linear acceleration method of analysis with Wilson-e modification. Different nonlinear models to simulate the behaviour of reinforced concrete under cyclic loading are used. A parametric study has been performed on a single story shear-type building with different natural frequencies supported on the surface of different soils to show the effect of different parameters on the behaviour of such structures under seismic excitation. These parameters include the type of soil, the soil conditions, the structure flexibility, and the type of analysis (elastic or inelastic). The results show that the soil rigidity, the soil layer depth, and the structure period have great influence on the response of such structures

    True Integer Valued Autoregressive Model with Skellam Distribution

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    In the present article, we introduce a new true integer valued autoregressive model of order one TPDINAR(1) for data sets on Z and either positive or negative correlations based on the Poisson difference (Skellam) marginal distribution and using a random walk variable (It). Properties of the model are derived. We consider several methods for estimating the unknown parameters of the model, and their properties are discussed. Simulations are carried out for the performance of these estimators for illustrative purposes. Finally, the analysis of real life time series data is presented, and its performance is compared to two different INAR(1) models that may also be used over the observed data

    Application of energy management coupled with fuel switching on a hydrotreater unit

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    AbstractIn the last decades, saving energy and protecting environment became the most important topics for search and survey. The energy engineer for any chemical process is obliged by restrictions of “Kyoto Protocol” for limitation of carbon dioxide emissions from fuel combustion, so he does his best to reduce utility consumption and thus reduce gas emission. Proper designing of the heat exchanger network (HEN) for any process is an effective and successful method to minimize utility consumption and therefore minimize gas emission (mainly carbon gases (CO2) and sulfur gases (SOx)). Fuel switching coupled with energy targeting achieved the least gas emission. In this work we choose a hydrotreater unit of a petroleum refinery as a case study due to its effective role and its obvious consumption of utility. We applied the methodology of energy targeting through HEN design (using pinch technology) at several values of mean temperature difference (ΔTmin); where the maximum percentage of energy saving was 37% for hot and cold utility which directly leads to percentage reduction of gas emission by 29% for CO2 and 17% for SOx. Switching fuel oil to other types of fuel realized gas emission reduction percentage where the maximum reduction established was through natural gas fuel type and reached 54% for CO2 and 90% for SOx. Comparison between existing design and the optimum ΔTmin HEN led to few modifications with the least added capital cost for the hydrotreater existing design to revamp it through four scenarios; the first one depended on fuel switching to natural gas while the second one switched fuel to diesel oil, in the third scenario we applied heat integration only and the fourth one used both of heat integration and fuel switching in a parallel way

    Acute pancreatitis in children: an experience with 50 cases

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    Background/purpose Acute pancreatitis in childhood is not common. It can be associated with severe morbidity and mortality. The role of clinical evaluation is vital as it can be misdiagnosed easily. The objective of this study was to review the etiology, presentation, diagnosis, management, and prognosis of acute pancreatitis in children and to assess the relevance of currently available prognostic criteria.Patients and methods Fifty children with acute pancreatitis admitted to the Pediatric Surgery Unit at the Al-Azhar University Hospitals, within the period January 1998 to December 2008 were retrospectively reviewed. They were diagnosed by clinical examination, laboratory, and radiological investigations, as well as by abdominal exploration.Results There were 25 boys and 25 girls. The median age was 9 years (range: 2–17 years). In the majority of cases, the main cause of acute pancreatic was idiopathic (17 patients), followed by trauma (10 patients). Most of the patients presented with abdominal pain (10 cases), vomiting (nine cases), jaundice (five cases), and an abdominal mass in computed tomography (48 cases).Conclusion Trauma is a major cause of pancreatitis in children. Early diagnosis, close monitoring, and proper intervention are mandatory to reduce the potential morbidity and mortality.Keywords: acute pancreatitis, children, morbidity, traum

    Discovery of a Histidine‐Based Scaffold as an Inhibitor of Gut Microbial Choline Trimethylamine‐Lyase

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    This is the peer reviewed version of the following article: Discovery of a Histidine‐Based Scaffold as an Inhibitor of Gut Microbial Choline Trimethylamine‐Lyase, which has been published in final form at https://doi.org/10.1002/cmdc.202000571. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Anaerobic choline metabolism by human gut microbiota to produce trimethylamine (TMA) has recently evolved as a potential therapeutic target because of its association with chronic kidney disease and increased cardiovascular risks. Limited examples of choline analogues have been reported as inhibitors of bacterial enzyme choline TMA‐lyase (CutC), a key enzyme regulating choline anaerobic metabolism. We used a new workflow to discover CutC inhibitors based on focused screening of a diversified library of small molecules for intestinal metabolic stability followed by in vitro CutC inhibitory assay. This workflow identified a histidine‐based scaffold as a CutC inhibitor with an IC50 value of 1.9±0.2 ΌM. Remarkably, the identified CutC inhibitor was able to reduce the production of TMA in whole‐cell assays using various bacterial strains as well as in complex gut microbiota environment. The improved efficiency of the new scaffold identified in this study in comparison to previously reported CutC inhibitors would enable optimization of potential leads for in vivo screening and clinical translation. Finally, docking studies and molecular‐dynamic simulations were used to predict putative interactions created between inhibitor and CutC

    Progressive Magnetic Resonance Image Reconstruction Based on Iterative Solution of a Sparse Linear System

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    Image reconstruction from nonuniformly sampled spatial frequency domain data is an important problem that arises in computed imaging. Current reconstruction techniques suffer from limitations in their model and implementation. In this paper, we present a new reconstruction method that is based on solving a system of linear equations using an efficient iterative approach. Image pixel intensities are related to the measured frequency domain data through a set of linear equations. Although the system matrix is too dense and large to solve by direct inversion in practice, a simple orthogonal transformation to the rows of this matrix is applied to convert the matrix into a sparse one up to a certain chosen level of energy preservation. The transformed system is subsequently solved using the conjugate gradient method. This method is applied to reconstruct images of a numerical phantom as well as magnetic resonance images from experimental spiral imaging data. The results support the theory and demonstrate that the computational load of this method is similar to that of standard gridding, illustrating its practical utility

    Formulation, evaluation and optimization of miconazole nitrate tablet prepared by foam granulation technique

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    The aim of our study was to utilize novel foam granulation technique in formulation of miconazole nitrate; a model hydrophobic drug as oral disintegrating tablets "ODT" particularly to enhance its bioavailability. Foam granulation technique has additional advantages over the other traditional granulation technique since; it enhances the granulation process and produce acceptable tablets. Fractional factorial design was used to investigate the effect of formulation and processing variables on the prepared miconazole ODT. The prepared granules were evaluated by measuring their density, flowability, granules size and shape, and granules wetting time. The quality attributes of the prepared tablets; drug content, tablet thickness, uniformity of weight, tablet tensile strength, friability, disintegration, and dissolution were also evaluated. The results indicated that, the prepared granules showed acceptable characteristics and is significantly affected by the disintegrant type, urea concentration, and the lubricant type. The quality attributes of the tablets were not affected by the processing parameters. From the prepared formulas; F20, F19, F12, and F20 displayed 18, 35, 35, and 40 seconds disintegration time respectively and the percent of dissolution after 15 minutes ranged from 94.4-100%. These results ascertained that foam granulation technique fulfill the requirement in preparation of miconazole ODT. Key words: miconazole nitrate, foam granulation, oral disintegrating tablet

    Microwave-assisted synthesis and antitumor evaluation of a new series of thiazolylcoumarin derivatives

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    A new series of thiazolylcoumarin derivatives was synthesized. The designed strategy embraced a molecular hybridization approach which involves the combination of the thiazole and coumarin pharmacophores together. The new hybrid compounds were tested for in vitro antitumor efficacy over cervical (Hela) and kidney fibroblast (COS-7) cancer cells. Compounds 5f, 5h, 5m and 5r displayed promising efficacy toward Hela cell line. In addition, 5h and 5r were found to be the most active candidates toward COS-7 cell line. The four active analogs, 5f, 5h, 5m and 5r were screened for in vivo antitumor activity over EAC cells in mice, as well as in vitro cytotoxicity toward W138 normal cells. Results illustrated that 5r has the highest in vivo activity, and that the four analogs are less cytotoxic than 5-FU toward W138 normal cells. In this study, 3D pharmacophore analysis was performed to investigate the matching pharmacophoric features of the synthesized compounds with trichostatin A. In silico studies showed that the investigated compounds meet the optimal needs for good oral absorption with no expected toxicity hazards
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