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Further Results on Designs Arising from Some Certain Corona Graphs
Get PDFIn this paper, we determine the partially balanced incomplete block designs and association scheme which are formed by the minimum dominating sets of the graphs C3°K2, and C4°K2. Finally, we determine the number of minimum dominating sets of graph G = Cn°K2 and prove that the set of all minimum dominating sets of G = Cn°K2 forms a partially balanced incomplete block design with two association scheme
Identities with Generalized Derivations and Automorphisms on Semiprime Rings
Get PDFIn this paper we prove some results which extend Theorem 4, Theorem 10 and Theorem 11 of Vukman [13] and proposition 2.3 of Thaheem and Samman [10]
Comparison of Beef Cattle Grazing Management Practices and their Effects on Runoff Water Quality in Louisiana
Get PDFManagement-intensive grazing (MIG) allows better use of grazed forage crops with short-duration grazing in small paddocks and with this study; the water quality was compared for two grazing management methods. Year-round grazing with MIG and continuous stocking (CS) were compared. Four 0.81-ha plots for two replications of the grazing systems were established. Twenty 0.04 ha (0.1 ac) paddocks, established with power fencing, allowed daily cattle rotation in MIG system. Continuous grazing and MIG used the same stocking rate on each experimental plot (0.81 ha). Each year, two crossbredbeef (Bos taurus) heifers (390 kg ± 12 kg; 12-14 mo at start) were maintained on each plot year-around for 3 yr, with additional yearling heifers added to maintain similarforage availability between stocking methods.
Common bermudagrass (Cynodon dactylon [L] Pers.) was grazed in summer and annual ryegrass (Lolium multiflorum Lam.) was over-seeded into the sod during October for winter and spring grazing. Forage mass was determined monthly and available forage dry matter (DM) was maintained at approximately 1120 kg DM ha-1 Runoff water samples were collected during 42 rainfall events from May 2001 through March 2004. No significant treatment differences (P > 0.10) were found in most of the water quality parameters. Runoff as a percentage of the 3-yr average annual rainfall of 1869 mm was 34% for MIG and 42% CS. The average flow-weightedconcentrations of soluble reactive phosphorus (SRP) varied from 5.08 mg P L–1 (ppm) to 8.22 mg P L–1 (ppm) while the NH+4–N ranged from 1.07 mg N L–1 (ppm) in year one to 10.11 mg N L–1 (ppm) for the second year (P < 0.05) for year effect. Total annual average forage production was greater (P < 0.05) in the MIG compared to CS with19,796 kg ha-1 for MIG vs. 16,964 kg ha-1 for CS. Beef production also increased with the MIG system with an annual total beef gain from MIG at 422 kg ha-1 y-1 vs. CS at 330 kg ha-1 yr-1.
Geoelectrical Survey for Groundwater Potential in Song and Environs NE, Nigeria
Get PDFAbstract: Seventeen Vertical Electrical soundings (VES) using the Schlumberger configuration with current electrode spacing of AB/2 = 80m were carried out in Song and environs of Adamawa State of Nigeria to study the groundwater potential. Sixteen VES showed a three-layer earth model; while the remaining one has four-layer earth model. The average thickness of the first layer is 2m with a mean resistivity of 75.14Ωm; representing the top soil and clay material. The second layer has an average thickness of 12.09m with a mean resistivity of 50.0Ωm. This layer is unconsolidated and highly weathered/fractured basement. The average resistivity value of the third layer is 5150Ωm and represents the fresh basement. Water samples were collected from Seven Boreholes (BH) and four Hand-Dug wells (HDW). The overall assessment of the sampled water in the area indicates an average pH value of 5.8, mean temperature of 28.96°C, an average turbidity value of 0.453NTU, and with a mean conductivity value of 159.39µs/cm. The water is mostly acidic with a moderate temperature, and turbidity. Total hardness has an average value of 98.78mg/l indicating a moderately soft water quality. All the Hand-Dug wells in the study area have high concentration of Nitrate and total Coliform count of 50.93mg/l to 67.17mg/l and 12cfu/ml to 27cfu/ml respectively. The high value can be attributed to anthropogenic activities such as chemical fertilizer application and indiscriminate dumping of house hold solid waste in the area as well as animals and human faeces. The high concentration of total coliform count was also observed in BH4 because of the shallow depth. Apart from the HDW and BH4 that are of shallow depth, the groundwater is generally good for human as well as industrial and agricultural uses
Primary and Secondary Crystallization Kinetic Analysis of Poly(Hexamethylene Succinate)
Get PDFIsothermal crystallization kinetics of poly(hexamethylene succinate) (PHS) were investigated by using differential scanning calorimetry (DSC). Primary and secondary crystallization behaviors were described satisfactorily by a modified Avrami model. The obtained results suggest that primary crystallization under isothermal conditions involves three-dimensional spherulite growth with athermal nucleation, and secondary crystallization displays approximate one-dimensional crystal growth
Finite Element Simulation of Jet Combustor Using Local Extinction Approach with in Eddy Dissipation Concept
Get PDFNon-premixed turbulent reacting flow in a methane-fuelled coaxial jet combustor has been studied numerically employing Reynolds Averaged Navier-Stokes (RANS) models. A Finite Element Method (FEM) based solver and Eddy Dissipation Concept (EDC) is used to simulate the methane air reaction inside the combustor. Simulations were carried out using the k-w (k-omega) turbulence model to handle the fluid flow simulation along with heat transfer and chemical reaction. The results were compared to available LES numerical results and experimental data for predicting velocity, and temperature fields. Velocity, temperature and concentration of the different species are also plotted at different cross sections of the methane burner
Effects of Pressure Gradients on Energy Dissipation Coefficient
Get PDFIn this study energy dissipation coefficient and entropy generation process in characteristic wall shear flows have been investigated. Effect of pressure gradients on energy dissipation coefficient for flows undergoing “bypass” transition from laminar to turbulent state has been studied. Reynolds-Averaged Navier-Stokes (RANS) models and Direct Numerical Simulations (DNS) are implemented to study the energy dissipation coefficient and local entropy generation in pre-transitional and transitional regions. Three of these RANS models are transitional models such as, traditional SST k-w (2eq), SST k-w (4eq) and k - kl -w and the results are compared with DNS. Four simulations have been performed for (1) zero, (2) favorable, (3) adverse and (4) strong-adverse pressure gradient cases. The numerical results show that the pressure gradient has a significant effect on energy dissipation coefficient and entropy generation
A Heat Exchanger Networks Synthesis Approach Based on Inherent Safety
Get PDFAn approach to incorporate inherent safety in the synthesis of heat exchanger networks (HEN) based on optimal layouts is given in this work. Hot and cold streams are produced in a set of facilities and some of these facilities may release toxic gas. The geographical allocation where each produced hot and cold stream is then incorporated in the conventional HEN synthesis problem. The number of heat exchangers, area requirement, energy consumption and energy configuration are thus optimally determined. Given are flows, inlet and outlet temperatures for each cold and hot stream as well as sufficient information on cooling and heating services. The annual cost is minimized while allowing for specification of constraints on matches, heat loads and streams splitting. The underlined idea is that inherent safety is achieved when simultaneously producing HEN and optimal facility layouts where risk due to toxic releases is also minimized. The numerical evidence indicates that inclusion of safety layouts with allocations of hot/cold streams can modify conventional HEN synthesis. The resulting model is a highly nonlinear mixed integer program (MINLP)
Molecularly Imprinted Membranes for Separation
Get PDFAmong various studies on molecular imprinting, the application of molecular imprinting to membrane separation is still a novel study though the first application was reported in 1962. Molecular recognition sites introduced into polymeric membranes by applying molecular imprinting leads to enhancement of permselectivity. In membrane separation, not only permselectivity but also flux (throughput) is important factors. In membrane separation, it is hard to simultaneously enhance both factors. From this, it was revealed that nanofiber or molecularly imprinted nanofiber membranes had potential to enhance both key factors. In the present short review, the application of molecular imprinting to membrane separation will be briefly surveyed
Measurement of PM2.5 and Water-Soluble Ions at Central Tokyo, Japan and Source Apportionment
Get PDFAir pollution by fine particulate matter, PM2.5 has been inviting considerable concerns in East Asia. This study then aimed to characterize PM2.5 and its water-soluble ions collected at Shibuya, central Tokyo, Japan from July 2013 to May 2015, in order to better understand the air pollution mechanism and potential sources of PM2.5 of the city. Analytical results showed the PM2.5 was a mixture of aggregates of formless particles and its concentration ranged from 5.4 to 39μg/m3, with a mean of 14 ± 6.7μg/m3 (n=46). SO42- and NH4+ were abundant in PM2.5 and their presence mostly determined the variation of PM2.5 level. High concentration episodes were found in the season when air masses came from Asian continent, and a long-range transport of urban aerosols and soil-derived particles was suggested by changes in the chemical compositions