60 research outputs found

    Simulation of Hydrodesulphurization (HDS) Unit of Kaduna Refining and Petrochemical Company Limited

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    This research was carried out to simulate the Hydrodesulphurization unit using ASPEN HYSYS with the aim of removing impurities such as Sulphur, Nitrogen and Oxygen in raw Kerosene. The simulation is based on conditions and parameters (mass flow rates, temperature and pressure readings) obtained from the Linear Alkyl Benzene (LAB) plant of the Kaduna Refining and Petrochemical Company (KRPC). After the successful completion of the simulation, total removal of impurities was achieved as the concentration of sulphur, nitrogen and oxygen in mole fraction present in the treated Kerosene stream was approximately zero. The treated Kerosene composition indicated 0.0021, 0.3342, 0.3322 and 0.3315 mole fractions of n-C13, n-C14, n-C15 and n-C16 respectively. Key words: Simulation, Hydrodesulphurization, Aspen Hysys, Impurities

    Area-level deprivation and adiposity in children: is the relationship linear?

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    OBJECTIVE: It has been suggested that childhood obesity is inversely associated with deprivation, such that the prevalence is higher in more deprived groups. However, comparatively few studies actually use an area-level measure of deprivation, limiting the scope to assess trends in the association with obesity for this indicator. Furthermore, most assume a linear relationship. Therefore, the aim of this study was to investigate associations between area-level deprivation and three measures of adiposity in children: body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). DESIGN: This is a cross-sectional study in which data were collected on three occasions a year apart (2005-2007). SUBJECTS: Data were available for 13,333 children, typically aged 11-12 years, from 37 schools and 542 lower super-output areas (LSOAs). MEASURES: Stature, mass and WC. Obesity was defined as a BMI and WC exceeding the 95th centile according to British reference data. WHtR exceeding 0.5 defined obesity. The Index of Multiple Deprivation affecting children (IDACI) was used to determine area-level deprivation. RESULTS: Considerable differences in the prevalence of obesity exist between the three different measures. However, for all measures of adiposity the highest probability of being classified as obese is in the middle of the IDACI range. This relationship is more marked in girls, such that the probability of being obese for girls living in areas at the two extremes of deprivation is around half that at the peak, occurring in the middle. CONCLUSION: These data confirm the high prevalence of obesity in children and suggest that the relationship between obesity and residential area-level deprivation is not linear. This is contrary to the 'deprivation theory' and questions the current understanding and interpretation of the relationship between obesity and deprivation in children. These results could help make informed decisions at the local level

    Strategic crossing of biomass and harvest index—source and sink—achieves genetic gains in wheat

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    To accelerate genetic gains in breeding, physiological trait (PT) characterization of candidate parents can help make more strategic crosses, increasing the probability of accumulating favorable alleles compared to crossing relatively uncharacterized lines. In this study, crosses were designed to complement “source” with “sink” traits, where at least one parent was selected for favorable expression of biomass and/or radiation use efficiency—source—and the other for sink-related traits like harvest-index, kernel weight and grains per spike. Female parents were selected from among genetic resources—including landraces and products of wide-crossing (i.e. synthetic wheat)—that had been evaluated in Mexico at high yield potential or under heat stress, while elite lines were used as males. Progeny of crosses were advanced to the F4 generation within Mexico, and F4-derived F5 and F6 generations were yield tested to populate four international nurseries, targeted to high yield environments (2nd and 3rd WYCYT) for yield potential, and heat stressed environments (2nd and 4th SATYN) for climate resilience, respectively. Each nursery was grown as multi-location yield trials. Genetic gains were achieved in both temperate and hot environments, with most new PT-derived lines expressing superior yield and biomass compared to local checks at almost all international sites. Furthermore, the tendency across all four nurseries indicated either the superiority of the best new PT lines compared with the CIMMYT elite checks, or the superiority of all new PT lines as a group compared with all checks, and in some cases, both. Results support—in a realistic breeding context—the hypothesis that yield and radiation use efficiency can be increased by improving source:sink balance, and validate the feasibility of incorporating exotic germplasm into mainstream breeding efforts to accelerate genetic gains for yield potential and climate resilience

    Transcriptional profile of breast muscle in heat stressed layers is similar to that of broiler chickens at control temperature

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    Abstract Background In recent years, the commercial importance of changes in muscle function of broiler chickens and of the corresponding effects on meat quality has increased. Furthermore, broilers are more sensitive to heat stress during transport and at high ambient temperatures than smaller egg-laying chickens. We hypothesised that heat stress would amplify muscle damage and expression of genes that are involved in such changes and, thus, lead to the identification of pathways and networks associated with broiler muscle and meat quality traits. Broiler and layer chickens were exposed to control or high ambient temperatures to characterise differences in gene expression between the two genotypes and the two environments. Results Whole-genome expression studies in breast muscles of broiler and layer chickens were conducted before and after heat stress; 2213 differentially-expressed genes were detected based on a significant (P < 0.05) genotype × treatment interaction. This gene set was analysed with the BioLayout Express3D and Ingenuity Pathway Analysis software and relevant biological pathways and networks were identified. Genes involved in functions related to inflammatory reactions, cell death, oxidative stress and tissue damage were upregulated in control broilers compared with control and heat-stressed layers. Expression of these genes was further increased in heat-stressed broilers. Conclusions Differences in gene expression between broiler and layer chickens under control and heat stress conditions suggest that damage of breast muscles in broilers at normal ambient temperatures is similar to that in heat-stressed layers and is amplified when broilers are exposed to heat stress. The patterns of gene expression of the two genotypes under heat stress were almost the polar opposite of each other, which is consistent with the conclusion that broiler chickens were not able to cope with heat stress by dissipating their body heat. The differentially expressed gene networks and pathways were consistent with the pathological changes that are observed in the breast muscle of heat-stressed broilers

    Studi Otomasi Dasar pada Sistem Miniplant Boiler dan Heat Exchanger Serta Pengamatan Sistem melalui HMI dan Database

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    Pada miniplant Boiler dan Heat Exchanger, dibutuhkan sistem untuk mengamati sistem secara keseluruhan. Dibutuhkan sistem tambahan berupa perangkat antar-muka dan sistem basis data sehingga pengamatan dan validasi model dapat dilakukan dengan lebih baik. Layer 0 merupakan sensor network. Pada Fasa ini, dibuat dokumen tentang instrumen yang digunakan sebagai Basic Process Control System (BPCS) dan Safety Control System (SCS). Hasil dari pengecekan didapatkan instrumen pengukuran temperatur memiliki kesalahan rentang sebesar 15%-50%. Layer 1 merupakan controller network. Pada sistem ini, digunakan SLC (Single Loop Controller) YS1700. Terdapat 2 SLC yang digunakan, yaitu SLC01 sebagai pengontrol level pada tangki 11, dan SLC02 sebagai pengontrol temperatur pada keluaran penukar kalor. Layer 2 merupakan unit control network. Pada layer ini terdiri dari komponen OPC (OLE for Proces Control), antar-muka dan basis data

    Effect of etching conditions on pore shape in etched ion-track polycarbonate membranes

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    We have undertaken a systematic investigation of the influence of methanol and applied transmembrane potential on the shape of conical pores produced by the track-etch technique. Heavy ion tracks in polycarbonate foils were chemically etched in an electrolytical cell under various conditions (different methanol content in the etchant, and applied potentials). It is found that the cone angle of the conical nanopore is dependent on the amount of methanol present in an alkaline etching solution as well as on the applied transmembrane potential. A combination of both these techniques is proposed to obtain conical nanopore with more exaggerated base opening. Controlling these conditions provide a route to fabricate controlled shape pores in polycarbonate membranes that have potential applications in a wide array of fields
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