Studies of microstructural imperfections of powdered Zirconium-based alloys

Different model based approaches of X-ray diffraction line profile analysis have been applied on the heavily deformed zirconium-based alloys in the powdered form to characterize the microstructural parameters like domain size, microstrain and dislocation density. In characterizing the microstructure of the material, these methods are complimentary to each other. Though the parameters obtained by different techniques are differently defined and thus not necessarily comparable, the values of domain size and microstrain obtained from the different techniques show similar trends.     

Effects of cooking methods and chemical tenderizers on survival of Escherichia coli O157:H7 in ground beef patties

This study evaluated chemical tenderizers and cooking methods to inactivate Escherichia coli O157:H7 in ground beef patties (model system for non-intact beef). Ground beef was inoculated with E. coli O157:H7 and mixed with (i) nothing (control), (ii) calcium chloride (CC) and flavoring agents (FA), (iii) CC, FA, and acetic acid (AA), (iv) sodium chloride (SC), sodium tripolyphosphate (ST), and potassium lactate (PL), and (v) the combination of SC, ST, PL, and AA. Patties were stored in aerobic or vacuum bags at − 20, 4, and 12 °C. Samples were grilled, broiled, or pan-fried to 60 or 65 °C. Total bacterial and E. coli O157:H7 populations remained unchanged during storage. Broiling was more effective in reducing E. coli O157:H7 than grilling and pan-frying, and acidified tenderizers reduced E. coli O157:H7 more than non-acidified tenderizers in broiling. Higher reductions were observed at 65 °C than 60 °C in broiled and grilled samples. These results indicate that acidified tenderizers and broiling may be useful in non-intact beef safety.     

Anisotropy of X-ray structural parameters of the three phase model in cellulose I

Anisotropy of X-ray structural parameters of the three phase model proposed by Mitra and Mukherjee (ref.2), has been investigated in the case of cellulose fibres of ramie, hemp and jute. The structural parameters have been determined separately from each of the observable equatorial reflections. It has been found that the parameter degree of crystallinity as defined in the model is in fact anisotropic at least in the samples studied. The parameter degree of paracrystallinity introduced by Mitra and Mukherjee was also found to be anisotropic. Several important correlations between the structural parameters have been drawn. It has been observed, in agreement with the recent findings of Hosemann and Balta Calleja (ref.10) that the greater the paracrystalline distortion, the smaller the ‘paracrystallite size’.     

Cytochrome P450 inhibitory potential of selected Indian spices — possible food drug interaction

Spices constitute an important group of food which is virtually indispensable in the culinary art. In a view, these spices feared to pose a probability to affect the disposition of conventional pharmaceuticals through inhibition of human cytochrome P450 (CYPs) enzymes. In the present study an approach has been made to evaluate the possible CYP inhibition potential with some Indian spices (Capsicum annuum, Murraya koenigii, Zingiber officinale) and their major bioactive compounds, in combination with pooled microsome; as well as commercially available recombinant human CYP3A4, CYP2D6, CYP2C9 and CYP1A2. Quantification of the bioactive compound was determined through RP-HPLC, in order to standardize the plant material. CYP–carbon monoxide (CYP–CO) complex assay result indicated that all the plants and their bioactive compounds have an interaction potential with CYPs. Fluoregenic assay results indicated that the spice extracts have higher inhibition potential comparing to their single bioactive molecule. The higher enzyme inhibition potential by the extracts may be related to the synergistic effects due to the presence of other constituents in the extract. Capsaicin and C. annuum showed the lowest IC₅₀ value and 6-gingerol and Z. officinale extract showed the highest IC₅₀ value among the entire sample tested. The entire sample showed significantly less (P < 0.001, P < 0.01) interaction potential than known inhibitors. These findings indicate that selected spices are unlikely to cause clinically relevant drug interactions involving the inhibition of major CYP isozymes.     

Thermal properties of nylon 6 fibres grafted with acrylic monomers

Thermal Properties of methyl methacrylate (MMA), ethyl methacrylate (EMA) and n-butyl methacrylate (n-BMA) grafted onto nylon 6 fibre with various graft levels were investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) and the results compared with that of parent nylon 6 fibre. It was found that the initial decomposition temperatures (IDT) of the grafted samples were lower than that of the parent nylon 6 fibre. On the other hand with all the three monomers, there was an increase in overall thermal stability followed by subsequent decrease with increase in the graft level. Among the grafted samples both the IDT and IPDT (initial procedural decomposition temperature) followed the order MMA-g nylon > EMA-g nylon < n-BMA-g nylon Differential thermal analysis shows a depression in glass transition temperature (T_g) as well as in melting temperature (T_m). In the case of the MMA and EMA grafted samples, the depression is small over a wide range of graft level. In the case of the n-BMA grafted samples, the depression is higher. A wide melting range was obtained in the grafted samples. Flammability studies also showed that with an increase in the graft level as well as an increase in the alkyl chain the ease of flammability increased as expressed by limiting oxygen index (LOI) values. The possible reasons for the phenomena occurred have been discussed.     

Studies on lipid and fatty acid compositions of puffer livers from Indian coastal waters with seasonal variation

The puffer fishes Chelonodon patoca, Sphaeroides oblongus, Lagocephalus lunaris, and L. inermis of Indian coastal waters are wasted in huge quantity. The livers of these fishes were investigated for their lipid contents and fatty acid compositions in different seasons. It was found that monsoon season is the suitable time to obtain the maximal lipids (40.1–48.8%) from their livers, an amount similar to cod liver lipid content (39.5–55.0%). The fatty acids were mostly saturates and monoenes (60–70%). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations (7–12%) were high during monsoon season. Neutral lipids were the predominant lipid class (>80%) and comprised triglycerides (277–674 mg/g) and cholesterol (0.6–3.1 mg/g). Quality indices of puffer liver lipids, e.g., specific gravity, refractive index, acid value, iodine value, saponification value and unsaponifiable matter, were evaluated. Puffer liver lipids were quantitatively and qualitatively comparable to other commercially important marine fish oils. The overall study suggests the possibility of future commercial utilization of liver lipids from puffer, an unconventional, cheap, and easily available source.     

Radiation-Induced graft copolymerization of methacrylic acid onto polypropylene fibers. V. Mechanical properties

Mechanical properties of polypropylene-g-poly(methacrylic acid) fibers, prepared by graft copolymerization of methacrylic acid onto polypropylene fiber using simultaneous gamma ray irradiation technique, were evaluated. In general, an improvement in the mechanical behavior of the polypropylene fiber by grafting was observed. Denier and initial modulus of the fiber showed a linear increase with the percent graft, and elongation showed an opposite trend. The results have been explained in terms of reinforcing effect of poly(methacrylic acid) grafts and reduction in the segmental mobility of the polymeric chains. Tenacity also increases up to certain graft level, beyond which a sharp decrease occurs, probably due to the influence on the compactness of the macromolecular chains with the further grafting.     

Radiation-induced graft copolymerization of methacrylic acid onto polypropylene fibers VI. Dyeing behavior

The dyeing behavior of polypropylene-g-polymethacrylic acid fibers prepared by graft copolymerization of methacrylic acid onto polypropylene fibers by gamma-ray irradiation was evaluated for their dyeability characteristics using two basic dyes, rhodamine B and methylene blue. An increase in the dye uptake and moisture regain with the increase in graft content was observed. Such behavior has been attributed to the hydrophilicity imparted to polypropylene fiber by the presence of polar carboxyl groups in polymethacrylic acid grafts. The dependence of rate of dyeing on the percentage graft was evaluated. The diffusion coefficient of the fiber showed an increase with the increase in graft content and has been related to the structural changes occurring during grafting.     

Activity measurements in aqueous mixed electrolyte solutions—III. HClCaCl2 mixtures of constant total ionic strength

Emf measurements have been made in cells without liquid junction of the type H₂/HX (m₁), MX_n(m₂)/AgCl, Ag . . (I) containing mixtures of HCl and CaCl₂ in different proportions, but at constant total ionic strength (I = 2, 1, 0.5). The measurements have been carried out at 5°C intervals over the temperature range 5–35°C. AgAgCl electrodes prepared by two different methods (thermal and thermoelectrolytic) were used of which the thermoelectrolytic electrodes were found to give more consistent results. The results when extrapolated properly lead to E° values at the different temperatures which agree well with those reported in literature. The application of the Pitzer method leads to the calculation of the ionic interaction coefficients α₁₂ and α₂₁, at the different constant ionic strengths. The nature of variation of these α's with the total mixture ionic strength at different temperatures has been considered.