In vitro digestibility,pasting, and structural properties of starches from different cereals

Starches isolated from seven different cereals were evaluated for their composition, physicochemical, in vitro digestibility, structural, morphological, and pasting properties. The in vitro starch digestion rate and estimated glycemic index (GI) of cereal starches were evaluated along with the impact of cooking on starch digestion. The cooking of starch slurries increased the rapidly digestible starch content from a range of 34.7–54.4% to a range of 60.5–78.5%. On the basis of hydrolysis index, the GI ranged from 83.6 to 91.8 and after cooking it increased from 95.1 to 98.6 for different cereal starches. Both the swelling power and solubility showed an increasing trend with rising temperature. Paste clarity of starches negatively correlated with fat content. The amylose content of various starches ranged from 17.7 to 24.7% and was negatively correlated to crystalline index (r = -0.975, p ≤ 0.05). XRD pattern revealed A-type pattern of crystalline starch, where crystallinity index ranging between 28.2 to 44.9%. FTIR revealed slight differences among chemical bonding of starches from different cereals. From scanning electron micrograph observations, wheat and barley starch granules proved smoother as compared to other cereal granules. Barley contained the highest (27.5 µm) and rice had the lowest (10.2 µm) size starch granules. The pasting properties were significantly (p ≤ 0.05) different for different cereal starches. Peak, breakdown, and final viscosities were the highest for maize starch (1725, 384, and 2112 mPa.s, respectively), whereas rice and oats exhibited the highest trough and setback viscosities (1420 and 954 mPa.s, respectively).     

Preparation of nickel ferrite from thermolysis of nickel tris(malonato)ferrate(III) heptahydrate precursor

The thermal decomposition of nickel tris(malonato)ferrate(III) heptahydrate precursor, Ni₃[Fe(CH₂C₂O₄)₃]₂·7H₂O has been investigated from ambient temperature to 1073 K in static air atmosphere using various physico-chemical techniques, i.e. TG–DTG–DSC, XRD, Mossbauer and IR spectroscopy. The precursor undergoes dehydration and decomposition simultaneously to yield nickel malonate and iron(II)malonate intermediates at 513 K. At higher temperature (593 K) these intermediate species decompose to NiO and α-Fe₂O₃, respectively. Finally, nickel ferrite, NiFe₂O₄ has been obtained as a result of solid-state reaction between Fe₂O₃ and NiO at a temperature (673 K) much lower than that of the conventional ceramic method. SEM analysis of the final thermolysis product reveals the formation of nickel ferrite nanoparticles with an average particle size of 40 nm. Magnetic studies show that these particles possess a saturation magnetization and Curie temperature of 2970 G and 843 K, respectively. Lower magnitude of these parameters as compared to the bulk values may be attributed to the ultrafine nature of the ferrite particles.     

Concurrent and predictive validity of the Psychopathy Checklist: Youth version across gender and ethnicity.

The concurrent and predictive validity of the Psychopathy Checklist: Youth Version (PCL:YV) were examined across gender and ethnicity using multiple outcome measures on a community-based sample of 130 adjudicated youths. The PCL:YV demonstrated concurrent validity with externalizing behavior problems but, it is important to note, was also associated with internalizing measures of negative affect. With a mean follow-up period of 3 years, the PCL:YV was found to predict general and violent recidivism in male, Native Canadian, and Caucasian youths. However, the PCL:YV demonstrated weaker concurrent and predictive validity with girls and failed to predict nonviolent recidivism in all subgroups. Implications of the findings for clinical practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cryoprocessing of cutting tool materials—a review

Cryoprocessing, a supplementary process to conventional heat treatment process, is the process of deep-freezing materials at cryogenic temperatures to enhance the mechanical and physical properties of materials being treated. The execution of cryoprocessing on cutting tool materials increases wear resistance, hardness, and dimensional stability and reduces tool consumption and down time for the machine tool set up, thus leading to cost reductions. The effects of cryoprocessing on tool steels and carbides, metallurgical aspects including reduced amount of retained austenite, precipitation of η-carbides, phase change in carbides, improvement in wear resistance, and applications are reviewed for manufacturing industry. Although it has been confirmed that cryogenic processing can improve the service life of tools, the degree of improvement experienced and the underlying mechanism remains ambiguous. The steps involved in cryoprocessing are critical enough to account for the significant incongruity in post-treated performance.     

Slurry Erosion Performance Study of Detonation Gun-Sprayed WC-10Co-4Cr Coatings on CF8M Steel Under Hydro-Accelerated Conditions

In the current investigation, cermet coatings (WC-10Co-4Cr) were deposited on CF8M steel by detonation gun (D-gun) thermal spraying process. Subsequently, the slurry erosion behaviors of the coated and bare steels were investigated using a high-speed erosion test rig. Slurry collected from an actual hydro power plant was used as the abrasive media. Effects of concentration (ppm), average particle sizes and rotational speed on the slurry erosion behaviors of coated and bare steels under different experimental conditions were studied. The analysis of eroded samples was done using SEM and stylus profilometry. Signatures of microcutting, fracture of well-bonded WC grains, and fragmentations were observed on the eroded surface of WC-10Co-4Cr coating, while signatures of formation of plowing, lips, shearing of platelet, formation of crater, and micro-cutting were observed on the eroded surface of CF8M steel.     

Uniformly thinned optical fibers produced via HF etching with spectral and microscopic verification

A method for producing uniformly thinned (etched) optical fibers is described, which can also be employed to etch optical fibers containing a Bragg grating (FBG) uniformly for evanescent-field-based sensing and other applications. Through a simple modification of this method, the fabrication of phase-shifted FBGs based on uneven etching is also shown. The critical role of how a fiber is secured is shown, and the success of the method is illustrated, by differential interference contrast microscopy images of uniformly etched FBGs. An etched FBG sensor for the monitoring of the refractive index of different glycerin solutions is demonstrated.     

Cover Picture: Tuning the Rate‐Dependent Stiffness of Materials by Exploiting Néel Relaxation of Magnetic Nanoparticles (Adv. Funct. Mater. 3/2008)

The effective stiffness of materials that are impregnated with magnetic nanoparticles can be modulated by magnetic fields if the nanoparticle Néel relaxation rates are slower than the characteristic deformation rates. A numerical analysis indicates that the deflection of magnetic dipoles against the applied magnetic field on deformation of the material provides the energy absorption necessary for the enhanced stiffness observed in drop ball impact tests. The penetration depth, fraction of the impact energy that is absorbed by the rotating dipoles, and the effective increase in stiffness are shown to depend uniquely on the ratio of the characteristic magnetic energy density relative to the elastic energy density, and on the shape of the impacting object.     

Haar wavelet approximate solutions for the generalized Lane–Emden equations arising in astrophysics

This paper provides a technique to investigate the solutions of generalized nonlinear singular Lane–Emden equations of first and second kinds by using a Haar wavelet quasi-linearization approach. The Lane–Emden equation is widely studied and is treated as a challenging equation in the theory of stellar structure for the gravitational potential of a self gravitating, spherically symmetric polytropic fluid which models the thermal behavior of a spherical cloud of gas acting under the mutual attraction of its molecules and subject to the classical laws of thermodynamics. The proposed method is based on the quasi-linearization approximation and replacement of an unknown function through a truncated series of Haar wavelet series of the function. The method is shown to be very reliable and easy to capture the solutions of generalized nonlinear singular Lane–Emden equations. The applicability of the method is shown by numerical tests on various cases of the generalized Lane–Emden equation and solutions are also reported in the neighborhood of a singular point.     

Stabilization of PbS Nanocrystals by Bovine Serum Albumin in its Native and Denatured States

PbS nanocrystals (NCs) are synthesized in aqueous phase within a temperature range of 40–80 °C in the presence of native and denatured states of bovine serum albumen (BSA) as the capping/stabilizing agent. The NCs are characterized with the help of field‐emission scanning electron microscopy, high‐resolution transmission electron microscopy, X‐ray diffraction, and energy‐dispersive X‐ray analysis. At 40 °C, large ball‐shaped NCs (145 ± 37 nm) with small surface protrusions are formed when 1 × 10^?4 g mL^?1 BSA is used. As the reaction temperature is increased towards 80 °C, the size of NCs decreases and they acquire somewhat cubic geometries (49.1 ± 7.0 nm) due to a change in the capping behavior of BSA between its native and denatured states. The native and denatured states of BSA are simultaneously studied by fluorescence spectroscopy using tryptophan emission, and pH measurements with respect to time and temperature. Gel electrophoresis is used to determine the polarity of the BSA capped NCs. Only the small sized NCs conjugated with relatively larger amounts of BSA show a displacement towards the positively charged electrode in comparison to larger NCs with lower amounts of BSA capping. It was concluded that the denatured state of BSA is more effective in controlling the crystal growth of PbS than its native state especially in the low concentration range.     

Impact of surface roughness on the electrical parameters of industrial high efficiency NaOH-NaOCl textured multicrystalline silicon solar cell

Sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) solution (1:1 ratio by volume) based texturization process at 80-82 °C is an easy, low cost and comparatively new and convenient option for fabrication of any multicrystalline silicon (mC-Si) solar cell. In the present study atomic force microscope is used to observe the intragrain surface in a miniscule area (3 μm × 3 μm) of NaOH-NaOCl textured surface by two and three dimensional analysis, roughness analysis and section analysis. The r.m.s value of the surface parameter of 7.0 nm ascertains the smoothness of the textured surface and further the surface reflectivity is minimized to 4-6% in the 500-1000 nm wavelength range by a proper silicon nitride anti-reflection coating. Comparing with the standard HF-HNO₃-CH₃COOH acid textured cell, the NaOH-NaOCl textured cell shows a comparatively lower value of series resistance of 7.17 mΩ, higher value of shunt resistance of 18.4 Ω to yield a fill factor of 0.766 leading to more than 15% cell efficiency in the industrial cell processing line. This AFM study yields different surface roughness parameters for the NaOH-NaOCl textured wafers which can be used as a reference standard for optimized texturing.