Treatment of composite wastewater of a cotton textile mill by thermolysis and coagulation

Catalytic thermal treatment (thermolysis) accompanied with coagulation was used for the removal of COD and color of composite wastewater from a cotton textile mill. CuSO4, FeSO4, FeCl3, CuO, ZnO and PAC were used as catalytic agents during thermolysis. Homogeneous copper sulphate at a mass loading of 6 kg/m3 was found to be the most active. Similarly during coagulation aluminum potassium sulphate [KAl(SO4)(2).16H2O] at a coagulant concentration of 5 kg/m3 was found to be the best among the other coagulants tested, namely, commercial alum, FeSO4, FeCl3 and PAC. During thermolysis, a reduction in COD and color of composite wastewater of about 77.9 and 92.85%, respectively, was observed at pH 12. Coagulation of fresh composite waste using aluminum potassium sulphate resulted in 88.62% COD reduction and 95.4% color reduction at pH 8. Coagulation of the supernatant obtained after treatment by catalytic thermolysis resulted in overall reduction of 97.3% COD and close to 100% color reductions at pH 8 at a lesser coagulant concentration of 3 kg/m3. The results reveal that the application of coagulation after thermolysis is most effective in removing nearly 100% of COD and color at a lower dose of coagulant. The sludge thus produced would contain lower inorganic mass coagulant and can be used as a solid fuel with high calorific value of about 16 MJ/kg, close to that of Indian coal.     

OpenSim: open-source software to create and analyze dynamic simulations of movement

Dynamic simulations of movement allow one to study neuromuscular coordination, analyze athletic performance, and estimate internal loading of the musculoskeletal system. Simulations can also be used to identify the sources of pathological movement and establish a scientific basis for treatment planning. We have developed a freely available, open-source software system (OpenSim) that lets users develop models of musculoskeletal structures and create dynamic simulations of a wide variety of movements. We are using this system to simulate the dynamics of individuals with pathological gait and to explore the biomechanical effects of treatments. OpenSim provides a platform on which the biomechanics community can build a library of simulations that can be exchanged, tested, analyzed, and improved through a multi-institutional collaboration. Developing software that enables a concerted effort from many investigators poses technical and sociological challenges. Meeting those challenges will accelerate the discovery of principles that govern movement control and improve treatments for individuals with movement pathologies.     

Effect of balconies on ventilation inducing aeromotive force on low-rise buildings

Data on mean wind pressure distribution on opposite walls of a five storey building model with smooth surface and also with balconies mounted thereon have been presented, and the effect of balconies on ventilation inducing wind forces has been discussed. It is shown that provision of balconies alters wind pressure distribution on windward wall but does not introduce significant change in it on the leeward side. Ventilative force across openings located centrally on opposite walls also remains almost unchanged due to the balconies. However, the ventilative forces across windows located at different heights on the windward wall only, get diminished at all the floors near the upstream end for obliquely incident wind, and over the entire wall width at the intermediate floors for the wind incidence at 90 ° angle on the wall. Enhancement in the ventilation inducing wind forces is caused at the top floors on the downstream side for obliquely incident wind, and near the ends of the wall at the ground and top floors for the wind impinging at right angle on the wall.     

Structural,Optical, and Ferroelectric Behaviors of Cu_(1-x)Li_xO(0≤x≤0.09) Nanostructures

We report structural,optical,and ferroelectric behaviors of lithium-doped copper oxide(Cu1-xLixO with x =0.0,0.05,0.07,and 0.09) nanostructures synthesized by hydrothermal method.The XRD pattern indicates the pure phase formation of CuO without any impurity,and the crystallite size is found to be increases for x =0–0.07 and decreases for x =0.09.FESEM analysis shows that the average size of Cu1-xLixO nanostructures increases with the increasing the Li-doping concentrations up to 7% and then decreases for 9% Li doping concentration.Moreover,Raman and photoluminescence spectrum also confirm the phase formation of CuO.A significant reduction in optical band gap is observed up to x =0.07,and then band gap increases for x =0.09 due to segregation of the impurities on the surface or grain boundaries,which may suppress the grain growth and results the enhancement in optical band gap.Moreover,a weak ferroelectricity is observed in CuO nanostructures for pure and 9% Li doping through polarization versus electric field(P–E).     

On the onset of thermal convection in rotating nanofluid layer saturating a Darcy–Brinkman porous medium

In this paper, the effect of rotation on the onset of thermal convection in a horizontal layer of nanofluid saturated by a Darcy–Brinkman porous medium is considered. A linear stability analysis based upon normal mode is used to find solution of the fluid layer confined between two free boundaries. The onset criterion for stationary and oscillatory convection is derived analytically and graphically. The effects of the concentration Rayleigh number, Taylor number, Lewis number, Darcy number and modified diffusivity ratio on the stability of the system are investigated. The sufficient conditions for the non-existence of overstability are also derived.     

Low cost CuInSe2 thin films production by stacked elemental layers process for large area fabrication of solar cell application

Low cost deposition of large area CuInSe₂ (CIS) thin films have been grown on Mo-coated glass substrate by simple and economic stacked elemental layer deposition technique in vacuum. The grown parameters such as concentration of Cu, In and Se elements have been optimized to achieve uniform thin film in vacuum chamber. The as-grown Cu/In/Se stacked layers have been annealed at 200 °C and 350 °C for 1 h in air ambient. The as-grown and annealed films have been further subjected to characterization by X-ray diffraction (XRD), optical absorption, atomic force microscopy (AFM) and I-V measurement techniques. XRD patterns revealed that as-grown Cu/In/Se stacked layers represent amorphous nature while annealed CIS film reproduces nano-polycrystalline nature with chalcopyrite structure. The optical band gap of annealed films increases with respect to air annealing which confirms the reduction of crystallite size. Surface morphology of as-grown Cu/In/Se stacked layers and annealed CIS thin films have been confirmed by AFM images. The electrical measurements show enhancement of conductivity which is useful for solar cell application.     

Microwave ECR plasma CVD of cubic Y2O3 coatings and their characterization

Yttrium oxide (Y₂O₃) thin films are deposited by microwave electron cyclotron resonance (ECR) plasma assisted metal organic chemical vapour deposition (MOCVD) process at a substrate temperature of 350 °C using indigenously developed metal organic precursors (2,2,6,6-tetra methyl-3,5-heptane dionate) yttrium, commonly known as Y(thd)₃ synthesized by ultrasound method. The deposited coatings are characterized by X-ray photoelectron spectroscopy, glancing angle X-ray diffraction, scanning electron microscopy, EDS and infrared spectroscopy. The characterization results indicate that it is possible to deposit non-porous coatings with excellent uniformity of a single phase cubic Y₂O₃ on various substrates by this process at reasonably low substrate temperature that is desirable in various manufacturing processes.     

THERMOELASTIC LAMB WAVES IN ELECTRICALLY SHORTED TRANSVERSELY ISOTROPIC PIEZOELECTRIC PLATE

The propagation of Lamb waves in a homogeneous, transversely isotropic, piezothermoelastic plate, which is stress free, electrically shorted, and thermally insulated (or isothermal), is investigated. Secular equations for the plate in closed form and isolated mathematical conditions for symmetric and antisymmetric wave mode propagation are derived in completely separate terms. It is shown that the motion of the purely transverse shear horizontal (SH) mode gets decoupled from the rest of the motion and remains unaffected due to piezoelectric, pyroelectric, and thermal effects. The secular equations for stress-free piezoelectric, thermoelastic, and elastic plates are deduced as special cases in the current analysis. At short wavelength limits the secular equations for symmetric and skew symmetric modes reduce to Rayleigh surface wave frequency equation, because a finite-thickness plate in such a situation behaves like a semi-infinite medium. The amplitudes of dilatation, electrical potential, and temperature change are also computed during the symmetric and skew symmetric motion of the plate. Finally, numerical solutions of various secular equations and other relevant relations are carried out for cadmium selenide (6 mm class) material. The dispersion curves, attenuation coefficients and amplitudes of dilatation, temperature change, and electrical potential for symmetric and antisymmetric wave modes are presented graphically to illustrate and compare the analytical results. The theory and numerical computations are found to be in close agreement. The coupling between the thermal/electric/elastic fields in piezoelectric materials provides a mechanism for sensing thermomechanical disturbances from measurements of induced electric potentials and for altering structural responses via applied electric fields. Therefore, the analysis will be useful in the design and construction of Lamb wave sensors, temperature sensors, and surface acoustic wave filter devices.     

Power efficient scheduling over fading channel for cross‐layer optimization

We consider the minimization of long‐term average power consumption for packet transmission between a mobile station and the base station over Nakagami‐m fading channel. Power consumption is minimized by intelligent transmission scheduling design, with the average queuing delay and joint packet loss across MAC and physical layers being confined below certain levels. The problem is formulated as an infinite horizon constrained Markov decision problem and solved by linear programming (LP) method. The primary intention of this paper is to provide a visible paradigm on using LP method to optimize the performance of mobile wireless communication systems. We elaborate the detailed mathematical solution with consistent simulation experiments and emphasize the effectiveness of adaptive transmission scheduling for cross‐layer QoS provisioning. Copyright © 2010 John Wiley & Sons, Ltd.     

Phase Diagram and Upper Critical Field of Homogeneously Disordered Epitaxial 3-Dimensional NbN Films

We report the evolution of superconducting properties with disorder, in 3-dimensional homogeneously disordered epitaxial NbN thin films. The effective disorder in NbN is controlled from moderately clean limit down to Anderson metal?Cinsulator transition by changing the deposition conditions. We propose a phase diagram for NbN in temperature-disorder plane. With increasing disorder, we observe that as k _F l??1 the superconducting transition temperature (T _c ) and normal state conductivity in the limit T??0 (?? ₀) go to zero. The phase diagram shows that in homogeneously disordered 3-D NbN films, the metal?Cinsulator transition and the superconductor?Cinsulator transition occur at a single quantum critical point, k _F l??1.