Effect of preservatives on the germination and growth of thermally injured fungal spores

Few strains of fungi isolated from various foodstuffs were investigated for their sensitivity to heat and subsequent tolerance to two preservatives; namely sorbic acid (SA) and butylated hydroxyanisole (BHA). Wide variations in their heat injury and sensitivity to the preservatives were noticed. Mucor was most sensitive to BHA while Trichoderma was most tolerant to SA. Cladosporium, Trichoderma and Fusarium were increasingly sensitive to heat. Heat injury also brought about extended lag periods and increased sensitivity to the preservatives.     

Microwave InxGa1?xAsyP1?y/InP f.e.t

Microwave performance of InxGa1?xAsyP1?y quaternary alloy metal-semiconductor field effect transistors (m.e.s.f.e.t.s) is reported. Liquid-phase epitaxy (l.p.e.) using a step cooling technique has been employed to grow submicrometre quaternary layers having room-temperature bandgaps of 0.9, 1.0, 1.05, 1.15 and 1.2eV. F.E.T.s having gate dimensions of 1×200 ?m and a channel length of 5 ?m have been fabricated using 1.15 and 1.2 eV quaternary alloys. A maximum d.c. transconductance of about 10 mS and a maximum available gain of about 7 dB at 10 GHz have been obtained.     

Studies on compressive failure features in syntactic foam material

Syntactic foam made by mechanical mixing of glass hollow spheres in epoxy resin matrix is characterized for compressive properties in the present study. Volume fraction of hollow spheres in the syntactic foam under investigation is kept at 67.8%. Effect of specimen aspect ratio on failure behavior and stress-strain curve of the material is highlighted. Considerable differences are noted in the macroscopic fracture features of the specimen and the stress-strain curve with the variation in specimen aspect ratio, although compressive yield strength values were within a narrow range. Post compression test scanning electron microscopic observations coupled with the macroscopic observations taken during the test helped in explaining the deviation in specimen behavior and in gathering support for the proposed arguments.     

Processing of Bimodal Grain-Sized Ultrafine-Grained Dual Phase Microalloyed V-Nb Steel with 1370 MPa Strength and 16 pct Uniform Elongation Through Warm Rolling and Intercritical Annealing

Ultrafine-grained dual phase microalloyed V-Nb steel with ultimate tensile strength of 1371 MPa and uniform elongation of 16 pct characterized by bimodal ferrite grain structure was obtained through warm rolling and subsequent intercritical annealing. The bimodal ferrite grain structure with uniform dispersion of Nb/V carbides and strong γ-fiber texture promoted high strain hardening rate and high uniform elongation and high strength is attributed to ultrafine-grained ferrite and martensite.     

Statistical optimization for lithium silicate catalyzed production of biodiesel from waste cooking oil

Lithium silicate is one of the suitable heterogeneous catalysts for biodiesel production. The possibilities of large number of combinations of different reaction parameters make the optimization of biodiesel production process over various heterogeneous catalysts highly tedious, necessitating the development of alternate strategies for parameter optimization. Here, Box-Behnken design (BBD) coupled with response surface methodology (RSM) is employed to optimize the process parameters required for the production of biodiesel from waste cooking oil using lithium silicate as catalyst. Simple method of impregnation was performed for the material preparation and the catalyst was analyzed using different techniques. It was found that the activity is directly proportional to the basicity data obtained from temperature programmed desorption (TPD) of CO₂ over various catalyst systems. The material exhibits macroporous morphology and the major crystalline phase of the most active catalyst was found to be Li₂SiO₃. The effects of different reaction parameters were studied and a biodiesel yield of 100% was obtained under the predicted optimum reaction conditions of methanol : oil molar ratio 15 : 1, catalyst amount 7 wt%, reaction temperature 55 °C and reaction time 2.5 h. The validation experiments showed a correlation coefficient of 0.95 between the predicted and experimental yield of biodiesel, which indicates the high significance of the model. The fuel properties of biodiesel obtained under the optimum conditions met the specifications as mentioned in ASTM D6751 and EN 14214 standards. Catalyst heterogeneity and low reaction temperature are the major attractions of the present biodiesel preparation strategy.     

Edible foxtail millet flour stabilises and retain the in vitro activity of blueberry bioactive components

Blueberries, a functional food, are rich in bioactive polyphenols and anthocyanins. However, the shelf life is short and requires cold storage. This study provides evidence that edible foxtail millet flour (FMF) efficiently sorbs only blueberry bioactive components (polyphenols and anthocyanins) but not sugars, improves their stability and retains the activity. The concentration of blueberry polyphenols and anthocyanins sorbed to FMF ranged from 6 to 113 and 4 to 41 mg g^?1, respectively. The concentration of bioactive components in one serving of blueberries (73 g) is equivalent to those present in 1.2 g of blueberry‐enriched foxtail millet flour (BFMF). The blueberry bioactive sorbed onto FMF remained stable for at least 16 weeks at 40 °C. BFMF eluates inhibited α‐glucosidase enzyme activity and scavenged the free radicals conferring that blueberry bioactive components in BFMF retained the activity. The sorption process described here provides a practical way of creating low glycemic protein‐rich edible flour enriched with plant bioactive compounds without sugars.     

Microstructural Characterization and Mechanical Properties of Powder Metallurgy Dual Phase Steel Preforms

In order to improve the mechanical properties of powder metallurgy (P/M) ferrite-pearlite steel, a dual phase (DP) ferrite-martensite steel was produced through intercritical annealing of sintered P/M preforms. Mi-crostructures of the sintered and DP steels were examined with optical, scanning and transmission electron microscopes. Mechanical properties were evaluated through hardness measurements and compression tests. Microstructural studies revealed that sintered steel contained polygonal ferrite-pearlite while the DP steel contained polygonal, lath and acicular ferrite along with lath-type martensite as microstructural constituents. In DP steels, with increasing mean preform density, the microstructure contained fine and continuous network of martensite colonies with minimum porosity. The work hardening rate vs plastic strain plots (Jaoul-Crussard analysis) of both the steels revealed typical three stage deformation behaviour for low and high mean preform densities. Compression tests revealed that, DP P/M steel displayed higher strength-plasticity combination than the sintered steel.     

Promising fluorescent dye for solar energy conversion based on a perylene perinone

We describe the synthesis of a dye based on a perylene perinone and evaluate its potential as the functional material for use in the luminescent solar concentrator (LSC). The dye extends the absorption wavelength of LSCs using the perylene-based dye Lumogen Red 305 by more than ~50 nm, translating into the collection of potentially 25% more photons at a reasonable fluorescent quantum yield and photostability. When the new perinone is used in a two-waveguide LSC in conjunction with Red 305, the integrated edge emission of the total LSC system may be increased more than 24% when compared to the Red 305 dye alone.