Wastewater emanating from color photograph processing units is usually in small quantities (5–20 L per day) and contains high concentrations of recalcitrant organic compounds. Disposal of such highly recalcitrant wastewater into a public sewer may result in an inhibiting effect on biological treatment system of a sewage treatment plant and thus these persistent organics can escape to receiving water bodies. A continuous full-scale treatment unit for such a small quantity of wastewater is not a viable option, economically and technically. In this study, a small batch type of an electrochemical reactor has been utilized to investigate the feasibility of electrochemical treatment of wastewater from a color photograph processing unit. The treatability studies were conducted using cast iron electrode. It was found that the cast iron electrode was efficient in removing both chemical oxygen demand and biochemical oxygen demand to the levels that meet the standards for discharge to surface water and public sewer. The energy consumption to meet the standards for sewer disposal was less compared to that of surface water disposal. The electrochemical reactor was found to be cost effective in both installation and operation for meeting the sewer disposal standards. It was concluded that the wastewater could be partially treated (pretreatment) electrochemically to meet the standard for sewer disposal rather than that of surface water disposal. 相似文献
Springback remains a major concern in sheet metal bending in fabricating any final product within the permissible tolerance.
Apart from the geometrical and material parameters, springback is significantly affected by the forming load also and the
present study is focused on it. Sheet metal bending process involves large rotation and strain as well as large springback
due to elastic recovery of the material. Therefore, a large deformation algorithm based Finite Element software was used to
model a typical sheet metal bending process employed in manufacturing cylindrical structures. A Total-Elastic-Incremental-Plastic
(TEIP) algorithm has been incorporated in an in-house software to handle large deformation and the elastic recovery during
the unloading process. In addition, experiments have been performed on aluminum, brass, copper and mild steel sheets and substantiated
with the FEM analysis. 相似文献
This paper presents the numerical study of mixed convection in a two‐sided lid driven porous cavity due to temperature and concentration gradients. The top and bottom walls are stationary and insulated. The left and right walls are moving at an equal velocity (Vo) in the same direction. The temperature and concentration are kept high at the right wall and low at the left wall. The governing equations are discretized using finite volume method. The pressure–velocity coupling is performed by the SIMPLE algorithm. A third order differed QUICK scheme is applied at the inner nodes and a second order central difference scheme is used at the boundary nodes. The flow behavior and heat transfer are analyzed for different nondimensional numbers, such as, 1 × 10?4 ≤ Ri ≤ 10, 1 × 10?4 ≤ Da ≤ 0.1 and 0.7 < Pr < 10. The present numerical results are compared with the literature and are in good agreement. For the above selected nondimensional numbers, the heat and fluid flow behavior is investigated using local and average Nusselt (Nu) and Sherwood (Sh) numbers. Results show that the convection flow is significant up to Da = 0.1, beyond that the effect of porosity is negligible. The effect of Prandtl number (Pr) on average Nu is found to increase significantly. 相似文献
Though present in small amounts, the minor constituents of dietary oils may supplement the dietary therapies for rheumatoid arthritis (RA). Hence, in the present study, we assessed the effect of minor constituents from sesame oil (SO) and rice bran oil (RBO) and their fatty acids on the severity of adjuvant‐induced arthritis in experimental rats. Rats were gavaged with 1 mL of SO or RBO or groundnut oil (GNO, control) with or without its minor components for a period 15 days before and 15 days after the induction of arthritis. Oxidative stress, markers of RA, eicosanoids, cytokines, paw swelling and joint integrity were measured in experimental and control rats. Results demonstrated that native SO and RBO but not SO and RBO stripped of their minor components decreased severity of paw inflammation, oxidative stress (lipid peroxides, protein carbonyls, nitric oxide), RA markers (RF and CRP), inflammatory eicosanoids (PGE2, LTB4 and LTC4) and cytokines (IL‐1β, IL‐6, MCP‐1 and TNF‐α) compared to control rats. Native SO and RBO inhibited hydrolytic enzymes (collagenase, elastase and hyaluronidase) in the synovial tissue compared to SO and RBO without minor components. The arthritic scores assessed based on the digital and X‐ray images indicated that native oils but not those without their minor components reduced the paw swelling and bone loss. Our results indicated that minor components of SO and RBO possess a significant degree of an anti‐arthritic effect and are responsible for down regulating inflammation in the experimentally induced arthritis in rats. 相似文献
Tetragonal BaTiO3 bulk samples are prepared using the solid‐state route in conjunction with intermediate high‐temperature annealing steps. The (002) and (200) X‐ray diffraction peaks near 2?~45° and 310, 520, and 720 cm?1 characteristic vibrational modes in Raman spectroscopic measurements confirm the tetragonal crystallographic structure of BaTIO3 bulk samples. The 1100°C annealed BaTiO3 sample showed optimal tetragonality ~1.016 and the same is used for BaTiO3–acrylonitrile butadiene rubber (NBR) composites at different BaTiO3 loading fractions in parts per hundred (PHR). These BaTiO3/NBR composite systems exhibit dual band microwave resonance, widening the operating window for microwave absorption applications. Eighty PHR BaTiO3/NBR composite exhibits microwave reflection losses (RL) at 9.5 and 16.5 GHz with ~?9 and ~?18 dB reflection losses, respectively. The onset of dual band is attributed to the ferroelectric‐induced dipolar relaxation at 9.5 GHz and its second‐order resonance at 16.5 GHz in such composite systems. 相似文献
Design centering is the term used for a procedure of obtaining enhanced parametric yield of a circuit despite the variations in device and design parameters. The process variability in nanometer regimes manifest into variations in these devices and design parameters. During design space exploration of analog circuits, a methodology to find design-instances with better yield is necessitated; this would ensure that the circuit will function as per specifications after fabrication, even with impact of statistical variations. We need to evaluate circuit performance for a given instance of a circuit-design identified by possessing a set of nominal values of device-design parameters. A lot of instances need be searched, having different sizes for a given circuit topology. HSPICE is very compute intensive. Instead, we employ macromodeling approach for analog circuits based on support vector machine (SVM), which enables efficient evaluation of performance of such circuits of different sizing during yield optimization loops. These performance macromodels are found to be as accurate as SPICE and at the same time, time-efficient for use in sizing of analog circuits with optimal yield. Process variability aware SVM macromodels are first trained and then used inside the Genetic algorithm loops for design centering of different circuits, subsequently resulting into sized-circuit instances having optimal yield. Post design centering, the sized circuits will be able to provide functions as per specifications upon fabrication. The application of this design centering approach as process variability analysis tool is illustrated on various circuits e.g. two stage op amp, voltage controlled oscillator and mixer circuit with layouts drawn into 90?nm UMC technology (Euro-practice). 相似文献
The hot deformation behavior of 2101 grade lean duplex stainless steel (DSS, containing ~5 wt pct Mn, ~0.2 wt pct N, and ~1.4 wt pct Ni) and associated microstructural changes within δ-ferrite and austenite (γ) phases were investigated by hot-compression testing in a GLEEBLE 3500 simulator over a range of deformation temperatures, Tdef [1073 K to 1373 K (800 °C to 1100 °C)], and applied strains, ε (0.25 to 0.80), at a constant true strain rate of 1/s. The microstructural softening inside γ was dictated by discontinuous dynamic recrystallization (DDRX) at a higher Tdef [1273 K to 1373 K (1000 °C to 1100 °C)], while the same was dictated by continuous dynamic recrystallization (CDRX) at a lower Tdef (1173 K (900 °C)]. Dynamic recovery (DRV) and CDRX dominated the softening inside δ-ferrite at Tdef ≥ 1173 K (900 °C). The dynamic recrystallization (DRX) inside δ and γ could not take place upon deformation at 1073 K (800 °C). The average flow stress level increased 2 to 3 times as the Tdef dropped from 1273 to 1173 K (1000 °C to 900 °C) and finally to 1073 K (800 °C). The average microhardness values taken from δ-ferrite and γ regions of the deformed samples showed a different trend. At Tdef of 1373 K (1100 °C), microhardness decreased with the increase in strain, while at Tdef of 1173 K (900 °C), microhardness increased with the increase in strain. The microstructural changes and hardness variation within individual phases of hot-deformed samples are explained in view of the chemical composition of the steel and deformation parameters (Tdef and ε).
The single and double ionization of a free C60 molecule in collisions with fast heavy (F and Si) ions is investigated using a recoil ion time-of-flight mass spectrometer. The projectile charge state (qp) dependence has also been investigated. A linear qp-dependence has been explained in terms of a plasmon excitation model. In addition, continuum electron spectroscopy has been used to detect the electron emission from fullerenes. The measured electron angular distribution for the fullerene target is compared with that for a gaseous target at a fixed electron energy. The ratio of forward-to-backward cross section for C60 is quite different from that for Ne. 相似文献