Standardization of seed ball media for fodder sorghum to increase green cover and fodder availability in degraded lands

Fodder sorghum (Sorghum bicolor L.) is a tall, erect annual grass. It is a drought resistant crop due to its effective root system. A seed ball is one of the low-cost technologies which was prepared with locally available materials on the farm. In seed balls, the seeds are protected from external factors. At the same time, vigorous seedling was established through seed ball. In order to improve the degraded lands with green cover, the following experiment was framed and carried out. Seed balls were prepared with a combination of red soil and vermicompost at different ratios with 230-250ml of water per kg of medium to get an optimum size and quality. After the preparation, seed balls were shade dried for 24-36 hrs. Among the different ratio of media combinations, 2:1 and 4:2 ratio was found to be the best media for seed balls preparation with good physical and physiological qualities. The maximum seedling quality parameters speed of germination (7.6), germination (98%), root length (10.6 cm), shoot length (19.4 cm) and vigour index (2900) obtained in the present study were due to vermicompost, which contained an optimum concentration of nutrients that helped improve the seedling vigour. This experiment confirmed that using seed balls with best media combinations for the regeneration of degraded lands was very effective

Biosorption of aniline blue from aqueous solution using a novel biosorbent Zizyphus oenoplia seeds: Modeling studies

This article presents the feasibility for the removal of Aniline Blue dye (AB dye) from aqueous solution using a low cost biosorbent material Zizyphus oenoplia seeds. In this study, a batch mode experiments of the adsorption process were carried out as a function of pH, contact time, concentration of dye, adsorbent dosage and temperature. The experimental data were fitted with Freundlich and Langmuir isotherm equations. The feasibility of the isotherm was evaluated with dimensionless separation factor (RL). The kinetic data of sorption process are evaluated by using pseudo-first order and pseudo-second order equations. The mode of diffusion process was evaluated with intra-particle diffusion model. The thermodynamic parameters like change in enthalpy (ΔHº); change in entropy (ΔSº) and Gibbs free energy change (ΔGº) were calculated using Van’t Hoff plot. The biosorbent material was characterized with Fourier Transform Infrared (FTIR) spectroscopy and the morphology was identified with Scanning Electron Microscope (SEM) in before and after adsorption of AB dye

Disorder in Ho2Ti2-x Zr x O7: pyrochlore to defect fluorite solid solution series.

Pyrochlore (A2B2O7) is an important, isometric structure-type because of its large variety of compositions and structural derivatives that are generally related to different disordering mechanisms at various spatial scales. The disordering is key to understanding variations in properties, such as magnetic behavior or ionic conduction. Neutron and X-ray total scattering methods were used to investigate the degree of structural disorder in the Ho2Ti2-x Zr x O7 (x = 0.0-2.0, Δx = 0.25) solid solution series as a function of the Zr-content, x. Ordered pyrochlores (Fd3̄m) disorder to defect fluorite (Fm3̄m) via cation and anion disordering. Total scattering experiments with sensitivity to the cation and anion sublattices provide unique insight into the underlying atomic processes. Using simultaneous Rietveld refinement (long-range structure) and small-box refinement PDF analysis (short-range structure), we show that the series undergoes a rapid transformation from pyrochlore to defect fluorite at x ≈ 1.2, while the short-range structure exhibits a linear increase in a local weberite-type phase, C2221, over the entire composition range. Enthalpies of formation from the oxides determined using high temperature oxide melt solution calorimetry support the structural data and provide insight into the effect of local ordering on the energetics of disorder. The measured enthalpies of mixing are negative and are fit by a regular solution parameter of W = -31.8 ± 3.7 kJ mol-1. However, the extensive short-range ordering determined from the structural analysis strongly suggests that the entropies of mixing must be far less positive than implied by the random mixing of a regular solution. We propose a local disordering scheme involving the pyrochlore 48f to 8a site oxygen Frenkel defect that creates 7-coordinated Zr sites contained within local weberite-type coherent nanodomains. Thus, the solid solution is best described as a mixture of two phases, with the weberite-type nanodomains triggering the long-range structural transformation to defect fluorite after accumulation above a critical concentration (50% Ti replaced by Zr)

A new experiment for investigating evaporation and condensation of cryogenic propellants

© 2015 Elsevier Ltd. All rights reserved. Passive and active technologies have been used to control propellant boil-off, but the current state of understanding of cryogenic evaporation and condensation in microgravity is insufficient for designing large cryogenic depots critical to the long-term space exploration missions. One of the key factors limiting the ability to design such systems is the uncertainty in the accommodation coefficients (evaporation and condensation), which are inputs for kinetic modeling of phase change. A novel, combined experimental and computational approach is being used to determine the accommodation coefficients for liquid hydrogen and liquid methane. The experimental effort utilizes the Neutron Imaging Facility located at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland to image evaporation and condensation of hydrogenated propellants inside of metallic containers. The computational effort includes numerical solution of a model for phase change in the contact line and thin film regions as well as an CFD effort for determining the appropriate thermal boundary conditions for the numerical solution of the evaporating and condensing liquid. Using all three methods, there is the possibility of extracting the accommodation coefficients from the experimental observations. The experiments are the first known observation of a liquid hydrogen menisci condensing and evaporating inside aluminum and stainless steel cylinders. The experimental technique, complimentary computational thermal model and meniscus shape determination are reported. The computational thermal model has been shown to accurately track the transient thermal response of the test cells. The meniscus shape determination suggests the presence of a finite contact angle, albeit very small, between liquid hydrogen and aluminum oxide

Contact angle measurement of liquid hydrogen (LH2) in stainless steel and aluminum cells

One of the key limitations to long-term space missions is to avoid propellant boil-off in a microgravity space environment. Even with the use of active and passive controls of propellants, boil off is inevitable. Long-term CFD simulations on propellant behaviors depend on evaporation/condensation coefficients (known as accommodation coefficients) which are in turn dependent upon the wetting characteristics. Phase change experiments were conducted in the BT-2 neutron imaging facility at the National Institute of Standards and Technology (NIST) by introducing vapor H2 in 10 mm Al6061 and SS316L test cells placed inside the 70mm ‘orange’ cryostat. Condensation is achieved by lowering the cryostat temperature below the saturation point and vice versa for evaporation. The high neutron cross-section of liquid H2 in comparison to both the vapor and the test cell materials allows for visualization of a distinct liquid-vapor interface. Multiple images are stacked to increase the signal-to-noise ratio and the meniscus edge is obtained by detecting the pixels with largest gradients in intensities at the liquid meniscus. The contact angle is obtained by curve fitting of the Young-Laplace equation to the detected meniscus. The contact angle for Al6061 and SS316 is found to be between 0° and 4°. The uncertainty arises from edge detection, magnification, and resolution limits of the neutron imaging setup. The test was conducted at a saturation temperature of 21K (1.215 bar). The results from the neutron experiments will be then used in conjunction with FEA thermal models and kinetic phase change models to extract accommodation coefficients.</jats:p