2,045 research outputs found
Design, analysis, and optimization of distributive mixing : with applications to micro and industrial flow devices
Synthesis and spectral studies on monometallic ruthenium (III) complexes of N-(2-hydroxysalicyliden-1-yl)methylenebenzoylhydrazide
AbstractA novel Schiff base ligand (H2L) derived from the condensation of benzoyl hydrazine and salicylaldehyde and its metal complexes with Ru (III) ion has been synthesized and characterized by elemental analyses, thermal analysis (TGA), conductance measurements, magnetic moments IR, UV–vis spectra. The complexes were given the formulae [Ru(L-H)Cl2(H2O)] (1), [Ru(L-H)Cl2(py)] (2), [Ru(L-H)Cl2(2-pic)] (3), [Ru(L-H)Cl2(3-pic)] (4), [Ru(L-H)Cl2(4-pic)] (5). Molar conductance in DMF (N,N-dimethyl formamide) solution indicates that the complexes are non-electrolytes. Magnetic susceptibility measurements indicate that all the complexes are mononuclear and one-electron paramagnetic. Electronic spectral studies suggest six coordinate metal ions in its complexes. IR spectra reveal that H2L ligand coordinates in keto-form to ruthenium metal ion in its complexes. ESR studies of the complexes are also reported
Varieties and mulching influence on weed growth in wheat under Indo- Gangetic plain of India
Weeds are one of the primary factors responsible for reducing wheat yield. Despite, herbicides’ being one of the important components of weed management programme in India, but it was not adopted by resource poor farmers. Keeping these facts in view, a field experiment was carried out at Agricultural research farm, Institute of Agricultural sciences, Banaras Hindu University during the rabi (winter) season of the year 2012-13 to scrutinize the influence of ‘mulching’ and ‘varieties’ on weed control potential as well as growth and yield of wheat. The treatments comprised of five wheat varieties (C-306, K-8027, K-0307, DBW-39 and HD-2888) and four mulching treatments (No-mulch, paddy straw 6t/ha, maize straw 6t/ha, and saw dust 6t/ha). Surface application of paddy straw mulch 6t/ha considerably reduced the density and biomass of broad leafed weeds and grasses and showed higher weed control efficiency over other treatments like maize straw 6t/ha, saw dust 6t/ha and no-mulch. Varieties DBW-39 and K-0307 was highly effective in smothering of the weeds and produced higher dry matter accumulation, leaf area index, number of grain/earhead, biological yield and harvest index of wheat
Electrocatalytic properties of La1-xCuxCoO3 (0 ≤ x ≤ 0.8) film electrodes prepared by Malic Acid sol-gel method at pH=3.75.
La-based Perovskite-type oxides with composition La1-xCuxCoO3 (0 ≤ X ≤ 0.8) have been synthesized by malic acid sol-gel low temperature route at pH 3.75. In each preparation, nitrate salts of lanthanum, copper, cobalt and malic acid were taken as starting material. The pH of the solution was adjusted by using ammonia solution. Techniques used to know the physical properties of the materials were scanning electron microscope (SEM) powder X-ray diffraction (XRD). All the electrochemical viza cyclic voltammetry, roughness factor and anodic polarization studies have been performed in three electrode single compartment glass cell. For the purpose, materials were transferred in the form of oxide film electrode on Ni conducting support. XRD data showed the formation of almost pure phase of the material with hexagonal crystal geometry. The cyclic voltammetric study showed that each oxide electrode exhibited a pair of redox peaks prior to the oxygen evolution reaction (OER). The values of Tafel slope (78-90 mV decade-1) and reaction order (~ 1) indicate that each catalyst follows similar mechanistic path. The data of anodic polarization study shows that the substitution of Cu in place of La in the base oxide increases the electrocatalytic activity considerably. The value was found to be highest with 0.4 mol Cu substitution. Electrochemically active area of the material was determined in terms of roughness factor by recording the cyclic voltammograms at different scan rates in the potential region 0.0-0.1V. The roughness factor was observed to be highest with 0.2 mol Cu-substituted oxide
Effect of High Energy Materials on Sensitivity of Composite Modified Double Base CMDB Propellant System
The shock sensitivities (viz, impact and friction) of composite modified double-base (CMBD) ingredients, double-base (DB) matrix (SNC:CL) and the effect of high energy materials like ammonium perchlorate (AP), cyclotrimethylene trinitramine(RDX), cyclotetramethylene tetranitramine (HMX) and pentaerythritol tetranitrate (PTN) on a CMDB system, have been studied. Individual ingredients of DB matrix, i.e., spheroidal nitrocellulose (SNC) and desensitised nitroglycerine (casting liquid (CL), do not appear to be very sensitive to impact and friction, impact of 36.0 kg each. Various DB mixtures gave impact ranging between 56.5 to 61.5 cm and friction insensitivity of 36.0 kg for all the formulations. But addition of AP to DB matrix increases the impact and friction sensitivity tremendously, impact ranging from 15 to 24 cm and friction from 2.0 to 3.2 kg. Sensitivity-wise addition of RDX, HMX, and PETN to DB matrix follows AP while the addition of Al slightly reduces the sensitivity
Effect of co-substitution on the electrocatalytic properties of Ni1.5Fe1.5O4 for oxygen evolution in alkaline solutions.
Some ternary ferrites with composition CoxNi1.5-xFe1.5O4 (0.0 less than or equal to x les than or equal to 1.25) have been synthesized through NH4OH co-precipitation at 11.5 pH. Materials obtained in this way were tested for their electrocatalytic properties towards oxygen evolution reaction (OER), in the form of a film on Ni-support in alkaline solution. The study showed that the electrocatalytic properties of the material increased with partial substitution of Co for Ni in the base oxide (Ni1.5Fe1.5O4), the value being highest with 1.25 mol Co-substitution. At E = 850 mV vs Hg/HgO in 1M KOH at 25 degrees C, the electrode showed apparent current density 137.1 mA cm(-2), which is about 2.5 times higher than the base oxide. The Tafel slope values were ranged between 53-90 mV decade-1. A pair of redox peak, an anodic (E-Pa = 522 +/- 28 mV) and corresponding cathodic (E-Pc = 356 +/- 9 mV), was observed in the cyclic voltammetry (CV) study of the material. The thermodynamic parameters for the oxygen evolution reaction (OER) - namely the standard apparent electrochemical enthalpy of activation (Delta H-el degrees(not equal)), the standard enthalpy of activation (Delta H degrees(not equal)) and the standard entropy of activation (Delta s degrees(not equal)) - have also been determined by recording the anodic polarization curve in 1M KOH. The value of Delta H degrees(not equal) was observed to be almost similar with each oxide electrode. The Delta s degrees(not equal) values were highly negative and ranged between similar to -165 and similar to -207 J deg(-1) mol(-1). Phase and morphology of materials have been investigated by using physical techniques such as X-ray diffraction, infrared spectroscopy (IR) and scanning electron microscope (SEM)
The melon fruit fly, Bactrocera cucurbitae: A review of its biology and management
The melon fruit fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) is distributed widely in temperate, tropical, and sub-tropical regions of the world. It has been reported to damage 81 host plants and is a major pest of cucurbitaceous vegetables, particularly the bitter gourd (Momordica charantia), muskmelon (Cucumis melo), snap melon (C. melo var. momordica), and snake gourd (Trichosanthes anguina). The extent of losses vary between 30 to 100%, depending on the cucurbit species and the season. Its abundance increases when the temperatures fall below 32° C, and the relative humidity ranges between 60 to 70%. It prefers to infest young, green, soft-skinned fruits. It inserts the eggs 2 to 4 mm deep in the fruit tissues, and the maggots feed inside the fruit. Pupation occurs in the soil at 0.5 to 15 cm below the soil surface. Keeping in view the importance of the pest and crop, melon fruit fly management could be done using local area management and wide area management. The melon fruit fly can successfully be managed over a local area by bagging fruits, field sanitation, protein baits, cue-lure traps, growing fruit fly-resistant genotypes, augmentation of biocontrol agents, and soft insecticides. The wide area management program involves the coordination of different characteristics of an insect eradication program (including local area options) over an entire area within a defensible perimeter, and subsequently protected against reinvasion by quarantine controls. Although, the sterile insect technique has been successfully used in wide area approaches, this approach needs to use more sophisticated and powerful technologies in eradication programs such as insect transgenesis and geographical information systems, which could be deployed over a wide area. Various other options for the management of fruit fly are also discussed in relation to their bio-efficacy and economics for effective management of this pest
The mapping method as a toolbox to analyze, design, and optimize micromixers
The mapping method is employed as an efficient toolbox to analyze, design, and optimize micromixers. A new and simplified formulation of this technique is introduced here and applied to three micromixers: the staggered herringbone micromixer (SHM), the barrier-embedded micromixer (BEM), and the three-dimensional serpentine channel (3D-SC). The mapping method computes a distribution matrix that maps the color concentration distribution from inlet to outlet of a micromixer to characterize mixing in a quantitative way. Once the necessary distribution matrices are obtained, computations are fast and numerous layouts of the mixer are easily evaluated, resulting in an optimal design. This approach is demonstrated using the SHM and the BEM as typical examples. Mixing analysis in the 3D-SC illustrates that also complex flows, for example in the presence of back-flows, can be efficiently dealt with by using the new formulation of the mapping metho
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