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Sorghum is a multipurpose crop where all parts of the plant are used for human food, animal food, fuel and fabrication. In comparison to other cereal crops it requires little water and it is tolerant to poor soils and adverse climatic conditions. It is one of the most widely grown crops in India particularly in semi-arid and rain-fed regions where the potential for crop and livestock production is limited by the availability of water. During the kharif season (July to October), it occupies about 10 million ha of land and produces a large quantity of stover which is given to farm livestock. The rabi season crop (November to February) occupies about 6 million ha of land and is mainly dependent upon residual moisture in the soil and provides both grain and forage. The economic value of sorghum stover as fodder sometimes exceeds that of the grain because seasonal shortage of food is an acute problem during the dry season. Much effort has been expended on improving sorghum varieties (Burton, 1973; Gupta et al., 1976; Dongi and Paroda, 1978), mostly directed towards increasing the yield. Pederson et al. (1982) compared the quality and agronomic traits of 49 forage sorghum hybrids and suggested that the most rapid way to improve the quality of forage sorghum would be to improve its in vitro dry-matter (DM) digestibility. There are several new strains of sorghum which have been improved in terms of agronomic characters but there is little information on the nutritional quality of their stovers. Therefore the objective of this study was to evaluate the stovers of several new sorghum strains in terms of chemical composition, in sacco DM disappearance (DMD) and their silage quality.
We examined the association between life course body weight percentile trajectories and risk for preterm delivery (PTD). Data about women’s weight at birth, age 18, and before pregnancy were obtained by retrospective self-report in a cohort of 1410 black women in metropolitan Detroit. Growth mixture models were used to categorize women with similar weight percentile trajectories across these time points. Log-Poisson models were used to examine the association between the trajectory groups and PTD. Four trajectory groups with different beginning and endpoints of their weight percentiles (high-high, high-low, low-high and low-low) best fit the data. The groups with the highest prevalence of PTD were those that started low (low-high, 21%; low-low, 18%). The low-high group had a higher prevalence of PTD than the high-high trajectory group in unadjusted models (prevalence ratio=1.49 [95% confidence interval (CI) 1.11, 2.00]). The association became not significant after adjusting for maternal age at delivery, income, diabetes and hypertension. When compared with the high-high trajectory group, the low-low trajectory seemed to also have a higher prevalence of PTD after adjusting for maternal age at delivery, income, diabetes and hypertension (prevalence ratio=1.35 [95% CI 1.00, 1.83]). Results suggest that a woman’s risk for PTD is influenced by her body weight trajectory across the life course.
We present the late-time Hubble Space Telescope observations of two Gamma Ray Burst (GRB) associated supernovae (SNe), GRB 030329/SN 2003dh and XRF 060218/SN 2006aj. Using the multi-color data up to ~320 days after the burst, we constrain the late-time decay nature of these SNe. The decay rates of SN 2003dh are steeper than SN 2006aj. A comparison with two other GRB SNe, GRB 980425/SN 1998bw and the SN associated with XRF 020903, shows that the decay rates of SN 2003dh are similar to XRF 020903 and those of SN 2006aj are similar to SN 1998bw. The late-time decay rates are steeper than the 56Co→56Fe radioactive decay rate indicating that there is some leakage of gamma-rays. We also compare the late-time decay rates of nine type Ic SNe, including the SNe of long GRBs, Ic broad lined and normal Ics. The decay rates of the SNe sample show a remarkable similarity in I band at late-times with a scatter of ~10%.
Incorporation of properly designed nanostructures in solar cells improves light trapping and consequently their power conversion efficiencies. Due to its unique structure, a silicon nanowire (SiNW) matrix provides excellent light trapping and thus offers a promising approach for cost-effective, stable and efficient silicon thin film photovoltaics. Moreover, by decoupling the light absorption and carrier collection directions, radial junction solar cells built around the SiNWs allow the use of very thin active layers. As a matter of fact, radial PIN junctions with 9.2% power conversion efficiency have already been demonstrated on glass substrates with only 100 nm thick intrinsic hydrogenated amorphous silicon layers. The most straightforward way to further improve the short circuit current density is to use an active layer with a lower band gap. In this work, the performances of devices with two different low band gap materials, e.g., hydrogenated microcrystalline silicon (μc-Si:H) and hydrogenated amorphous silicon germanium alloy (a-SiGe:H) are presented. To the best of our knowledge, this is the first demonstration of a-SiGe:H radial junction solar cell.
We report on the structural and electrical characteristics of bulk and thin film of ternary oxide SmGdO3. Bulk sample of SmGdO3 was prepared by pelletizing and sintering the calcined mixture of predetermined amount of Sm2O3 and Gd2O3 powders. The crystalline structure of the sample was studied by X-ray diffraction measurements and Raman spectroscopy. Capacitance and leakage current measurements on bulk sample revealed a high and linear dielectric constant of ∼ 19 with low dielectric loss and leakage current which is suitable for gate dielectric application in CMOS logic devices and high-k MIM capacitors. In addition, the non-volatile resistive memory switching phenomenon was studied in thin films of SmGdO3 which were deposited by pulsed laser deposition using sintered pellet of SmGdO3 as target. Commercially available Pt/TiO2/SiO2/(100) Si was used as substrate and top Pt electrode of lateral dimension 40×40μm2 were deposited by sputtering to construct Pt/SmGdO3/Pt MIM devices. After initial forming process which occurred at comparatively higher voltage, the Pt/SmGdO3/Pt devices showed repeatable unipolar switching between high and low resistance states with low and well defined switching voltages. These properties indicate suitability of this material for the emerging logic and memory device applications.
A formalism for investigation of the propagation characteristics of various order short duration (pico second) Gaussian/dark hollow Gaussian laser pulse (DHGP) in a tunnel ionized plasma has been developed, which takes into account the electron-ion recombination. Utilizing the paraxial like approach, a nonlinear Schrödinger wave equation characterizing the beam spot size in space and time has been derived and solved numerically to investigate the transverse focusing (in space) and longitudinal compression (in time) of the laser pulse; the associated energy localization as the pulse advances in the plasma has also been analyzed. It is seen that in the absence of recombination the DHGP and Gaussian pulse undergo oscillatory and steady defocusing respectively. With the inclusion of recombination, the DHGP and Gaussian pulse both undergo periodic self-focusing for specific parameters. The DHGPs promise to be suitable for enhancement of energy transport inside the plasma.
High quality dilute nitride subcells for multijunction solar cells are achieved using GaInNAsSb. The effects on device performance of Sb composition, strain and purity of the GaInNAsSb material are discussed. New world records in efficiency have been set with lattice-matched InGaP/GaAs/GaInNAsSb triple junction solar cells and a roadmap to 50% efficiency with lattice-matched multijunction solar cells using GaInNAsSb is shown.
Amorphophallus paeoniifolius, popularly known as elephant foot yam, is an important tropical tuber crop in India. Its modified stem (corm) is consumed as a vegetable after boiling, baking or frying. Mealybug (Rhizoecus amorphophalli), a soft-bodied insect, infests the corms both in storage and in the field. Though pesticides are effective in controlling mealybugs, they can be hazardous to human health and the environment. Two experiments, one in storage followed by one in the field, were conducted during 2009 and 2010 at the Regional Centre of Central Tuber Crops Research Institute, Dumuduma, Bhubaneswar, India, to determine the effect of six low cost and environmentally safe management practices on mealybug. In the absence of mealybug control measures, mealybug numbers increased by 4–5 times during the storage period. The pest affected the quality of the corms and reduced subsequent field establishment and crop growth. Salt (NaCl) solution (1000 ppm), cow urine, cow dung slurry (2 kg of cow dung in 1 litre of water) and clay slurry (1 kg of clay in 1 litre of water) treatments were effective in reducing mealybug numbers and the associated corm damage. However, availability of cow urine, cow dung and clay slurry limit their usage. Common salt is cheap, widely available and easy to use in treating the corms prior to storage. Relative to untreated corms, those treated with salt solution recorded greater emergence when field planted as well as producing plants with more vigorous growth.
The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight to reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors’ viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future development. Electron microscopy; atom probe tomography; x-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Advances in surface probe microscopy have been reviewed recently and, therefore, are not included [D.A. Bonnell et al.: Rev. Modern Phys. in Review]. In this study particular attention is paid to studies that have pioneered the synergetic use of multiple techniques to provide complementary views of a single structure or process; several of these studies represent the state-of-the-art in characterization and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis, and complex structure evolution problems involving material damage. The future of microstructural characterization is proposed to be one not only where individual techniques are pushed to their limits, but where the community devises strategies of technique synergy to address complex multiscale problems in materials science and engineering.
Although Injury is being looked into as a major public health problem in India, most of the data coming is mortality related data from the National Crime Records Bureau and projections based on that data. There is complete absence if injury related data both surveillance data as well as outcome based data. Apex Trauma Center, All India Institute of Medical Sciences, New Delhi is one of the pioneering centers to understand the need to record the injury related data of all trauma cases which are admitted to the Apex Center, thus establishing a first of its kind hospital based Trauma Registry in India. This trauma registry will serve as a means for collating trauma data that will further help in the evaluation, prevention, and research of trauma care and can be used for quality control and planning future research and injury prevention activities, in India. Later, the center has an objective of networking all regional hospitals for data collection with an aim to establish a National Trauma Registry. Although several trauma registry software's exist from Western hemisphere but the Apex Trauma Center decided to formulate and designed its own Trauma Registry form and develop the related software which includes: Basic Identification; Demographic profile; Brought by personnel and vehicle; Condition at time of arrival; ED Interventions; Detailed Diagnosis; Definitive Procedures; Disposition/ Outcome The Trauma registry is being maintained, under the leadership of a Faculty and the data is collected and entered by the Trauma Nurse Coordinators, who follow the patient from admission to discharge. The data collection for the JPNATC Trauma Registry had started w.e.f. April 2009, but initially there were usual problems of data loss and non-availability of data. This has been overcome gradually and we hope that the registry will attain its full potential in another year or so.
Atomistic simulations have provided unprecedented insight into the structural and mechanical properties of nanocrystalline materials, highlighting the role of the non-equilibrium grain boundary structure in both inter- and intra-grains deformation processes. One of the most important results is the capability of the nanosized grain boundary to act as a source and sink for dislocations. However the extrapolation of this knowledge to the experimental regime requires a clear understanding of the temporal and spatial scales of the modelling technique and a detailed structural characterisation of the simulated samples. In this contribution some of the synergies that can be developed between atomistic simulations and experiments for this research field are briefly discussed by means of some typical examples.
Our surrounding environment is teeming with useful energy, waiting to be
harnessed (i.e., solar, wind, tidal, etc.). If this energy can be exploited
at the point where it is required, then the need to carry additional power
sources can be reduced. In recent years, magnetic shape memory alloys (MSMA)
have demonstrated an ability to convert mechanical energy to magnetic
energy. Such conversions have lead to the investigation of these alloys for
energy harvesting applications.
There are a number of issues to address when forming a MSMA/polymer
composite. The polymer must be stiff enough to transmit the induced strain
through the entire matrix, yet soft enough not to exceed the MSMA blocking
stress. Also, the polymer must not dampen any force applied before it can be
transmitted to the MSMA particles.
Ten polymers have been investigated for MSMA/polymer composites. The work
presented here will describe progress in nickel-manganese-gallium
(Ni-Mn-Ga)/polymer composite fabrication and characterization. Special
attention will be given to polymer selection, optimizing particle dispersion
and MSMA/polymer interfacial interactions.
Cylindrical 440C stainless steel specimens implanted with N and Ti were examined for their fatigue resistance and wear behavior by rolling contact fatigue (RCF) testing. The results obtained from RCF testing showed a 40% increase in the B-10 fatigue lifetime for N implanted and a 17% increase for Ti implanted 440C specimens compared to baseline, unimplanted 440C. Quantitative surface analysis by Auger Electron Spectroscopy (AES) was performed to determine the effects of process parameter optimization and ion beam masking on the elemental concentration profiles.
Internal friction behavior in cast 8-ply [0°1 P55Gr/Mg-0.6%Zr alloy and P55Gr/Mg-1%Mn composites as a function of vibratory strain amplitude was measured at 80 kHz using a Marxtype piezoelectric composite oscillator. Both the matrix and composite exhibited strain amplitude independent internal friction below ε ≈ 10−6, while significant strain amplitude dependence was noted at higher strain levels. A maxima in damping was observed for most of the specimens tested. Heat treatment to enlarge grain size was found to increase both the strain amplitude independent and dependent internal friction of the composite. Strain amplitude dependence of the internal friction, including the existence of the maxima, was explained by the Granato-Lucke (G-L) dislocation internal friction model. Dislocation densities obtained from various TEM images from the fiber-matrix interface were compared to values predicted by G-L theory.
PolySi films deposited with and without oxygen doping using rapid thermal chemical vapor deposition (RTCVD) have been investigated. Experimental results show that RTCVD systems can be used to provide high deposition rates ( 900-1000 Å/min at 700 °C) for both oxygen-doped and non-oxygen-doped polySi films. The surface roughness of the RTCVD polySi film is about half that of conventional LPCVD polySi films. The surface roughness and grain size of the RTCVD polySi film can be further reduced using oxygen doping. The catastrophic breakdown strength for capacitors using oxygen-doped polySi electrodes are improved compared with the breakdown strength for capacitors using non-oxygen-doped polySi electrodes. Electrical resistivities of B, P and As doped samples of polySi films with oxygen doping are found to be larger than those of polySi films without oxygen doping. Resistivities of silicides formed on the oxygen-doped polySi samples are approximately the same for those of silicides formed on non-oxygen-doped polySi samples.
A directionally solidified β + (γ + γ′) Ni-Fe-AI in-situ composite alloy of composition Ni50Fe30Al20 (at.%) has been used to investigate the effect of a plastically soft second phase on the mechanical behavior of a B2 ordered intermetallic alloy. This material exhibits extensive plasticity during compressive deformation at room temperature and fails in shear with extensive γ + γ′ lamellar or rod pull-out. The material also exhibits ∼10% tensile elongation to fracture at room temperature, with final fracture that includes substantial necking of the γ + γ′ lamellae or rods. Observation of slip lines and dislocation substructures discloses that the normally brittle β matrix undergoes extensive plasticity in order to deform compatibly with the more ductile γ phase. The plasticity of the β matrix is accomplished by the generation of glissile dislocations into the β matrix from the β/γ interface region and is enhanced because of a favorable β - γ orientation relationship for slip transfer. Ductility enhancement from interface-generated mobile dislocations generated from β-γ interfaces is compared to that observed in film-coated β-NiAl single crystals and FeAl polycrystals.
Monolithic Nb5Si3 films and microlaminates consisting of alternating, equally thick layers of Nb and Nb5Si3 were synthesized by magnetron sputtering. Thick monolithic Nb5Si3 films (25,000 nm) were deposited on a sapphire substrate to set process parameters and evaluate the microstructure and mechanical properties of as-deposited crystalline films. Nb5Si3/Nb micro-laminates with modulation wavelengths (i.e., bilayer thickness) of 40 and 200 nm were deposited on Nb substrates. Mechanical properties (elastic modulus, microhardness, compressive yield strength) of the films and microlaminates were studied using the nanoindentation method and Vickers microhardness. Mechanical property test results are presented.
Porous aluminum oxide membranes with a complete and even covering of alumina nanowires were formed in a one-step anodization process in dilute phosphoric acid electrolyte. The anodizing conditions can be adjusted to start forming alumina wires that originate on the surface of the porous alumina layer at the triple junction points (the edges of the hexagonal inter-pore structure where three pores meet). The wires tangle together as they become longer; eventually creating a tangled mesh layer above the porous oxide layer. SEM micrographs of the oxide cross section show tapered wires that are approximately 2 to 10 m long, depending on anodizing time, and range in width from a few nanometers to 50nm. The aluminum substrate can be chemically removed and the alumina barrier layer dissolved to leave a free standing porous alumina membrane with very high surface area alumina wires on one face. Some possible future applications of this high surface area structure involve filtration of liquids and gasses, combined with chemical functionalization on the large surface area.