Defect stabilization in ZnO nanorods by Mg2+ doping

Luminescent ZnO and Zn0.95Mg0.05O nanorods with length around 0.5 to 3 microm and diameter 100-150 nm were prepared by a facile solvothermal method. On hydriding at room temperature, a change of morphology from nanorods with aspect ratio 5-10 to particles of sizes 100 nm has been observed in both ZnO and Zn0.95Mg0.05O. While hydrided Zn0.95Mg0.05O showed an enhanced defect related green emission, the same got suppressed in hydrided ZnO. Even though it is observed that zinc vacancies are present in both as prepared ZnO and Zn0.95Mg0.05O, luminescence studies indicate that zinc vacancies get stabilized in Zn0.95Mg0.05O on hydrogenation.     

A comparison of analytical and data preprocessing methods for spectral fingerprinting

Spectral fingerprinting, as a method of discriminating between plant cultivars and growing treatments for a common set of broccoli samples, was compared for six analytical instruments. Spectra were acquired for finely powdered solid samples using Fourier transform infrared (FT-IR) and Fourier transform near-infrared (NIR) spectrometry. Spectra were also acquired for unfractionated aqueous methanol extracts of the powders using molecular absorption in the ultraviolet (UV) and visible (VIS) regions and mass spectrometry with negative (MS-) and positive (MS+) ionization. The spectra were analyzed using nested one-way analysis of variance (ANOVA) and principal component analysis (PCA) to statistically evaluate the quality of discrimination. All six methods showed statistically significant differences between the cultivars and treatments. The significance of the statistical tests was improved by the judicious selection of spectral regions (IR and NIR), masses (MS+ and MS-), and derivatives (IR, NIR, UV, and VIS).     

Identification of predominant lactic acid bacteria isolated from traditionally fermented vegetable products of the Eastern Himalayas

Gundruk, sinki and khalpi are lactic-fermented vegetable products of Sikkim in India, and inziangsang is a fermented leafy vegetable product of Nagaland and Manipur in India. A total of 65 samples of gundruk (25), sinki (12), khalpi (25) and inziangsang (3) were analysed for microbial counts. The population of lactic acid bacteria (LAB) as well as aerobic mesophilic counts were at the level of 10(7) cfu g(-1). Yeasts were detected only in few samples of sinki and khalpi. No moulds were detected. In order to identify the predominating organisms, a total of 269 strains of LAB were isolated from gundruk, sinki, khalpi and inziangsang samples. The phenotypic characteristics of these strains were determined followed by genotyping using RAPD-PCR, repetitive element PCR and species-specific PCR techniques. The major representatives of the LAB involved in these fermentations were identified as Lactobacillus brevis, Lactobacillus plantarum, Pediococcus pentosaceus, Pediococcus acidilactici and Leuconostoc fallax.     

Making a case for sustainable building materials to promote carbon neutrality in Indian scenario

Clean Technologies and Environmental Policy - Construction industry adds more than 35 percent of global emissions through the entire lifecycle procedure of the structure. Every stage of...     

Fermented foods in a global age: East meets West

Fermented foods and alcoholic beverages have long been an important part of the human diet in nearly every culture on every continent. These foods are often well‐preserved and serve as stable and significant sources of proteins, vitamins, minerals, and other nutrients. Despite these common features, however, many differences exist with respect to substrates and products and the types of microbes involved in the manufacture of fermented foods and beverages produced globally. In this review, we describe these differences and consider the influence of geography and industrialization on fermented foods manufacture. Whereas fermented foods produced in Europe, North America, Australia, and New Zealand usually depend on defined starter cultures, those made in Asia and Africa often rely on spontaneous fermentation. Likewise, in developing countries, fermented foods are not often commercially produced on an industrial scale. Although many fermented products rely on autochthonous microbes present in the raw material, for other products, the introduction of starter culture technology has led to greater consistency, safety, and quality. The diversity and function of microbes present in a wide range of fermented foods can now be examined in detail using molecular and other omic approaches. The nutritional value of fermented foods is now well‐appreciated, especially in resource‐poor regions where yoghurt and other fermented foods can improve public health and provide opportunities for economic development. Manufacturers of fermented foods, whether small or large, should follow Good Manufacturing Practices and have sustainable development goals. Ultimately, preferences for fermented foods and beverages depend on dietary habits of consumers, as well as regional agricultural conditions and availability of resources.     

Nitrogen doped porous carbon derived from EDTA: Effect of pores on hydrogen storage properties

N doped carbon samples have been prepared from commonly available precursor EDTA and thoroughly characterised using a variety of techniques. It has been found that with increase in annealing temperature graphitic character increases along with decrease in nitrogen content. During chemical activation by treatment with H₃PO₄, C atoms from the network structure get oxidised preferentially giving rise to larger pores, as confirmed by TEM and SAXS analysis. Possible mechanism of activation has been proposed based on NMR and XPS results. From NMR it is established that the activated samples consist of both orthophosphate (Q^o) and pyrophosphate (Q¹) structural units and are weakly linked to carbon network. Pore size has been correlated with hydrogen storage capacity and it has been found that the presence of large number of pores with lower diameter is preferable for getting better hydrogen storage capacity in porous carbon based materials.     

Novel pathways in bacteriocin synthesis by lactic acid bacteria with special reference to ethnic fermented foods

Food Science and Biotechnology - Ethnic fermented foods are known for their unique aroma, flavour, taste, texture and other sensory properties preferred by every ethnic community in this world...     

Impact of bathers on levels of Cryptosporidium parvum oocysts and Giardia lamblia cysts in recreational beach waters

Recreational beach water samples collected on weekends and weekdays during 11 consecutive summer weeks were tested for potentially viable Cryptosporidium parvum oocysts and Giardia lamblia cysts using the multiplexed fluorescence in situ hybridization (FISH) method. The levels of oocysts and cysts on weekends were significantly higher than on the weekdays (P<0.01). Concentrations of oocysts in weekend samples (n=27) ranged from 2 to 42 oocysts/L (mean: 13.7 oocysts/L), and cyst concentration ranged from 0 to 33 cysts/L (mean: 9.1 cysts/L). For the samples collected on weekdays (n=33), the highest oocyst concentration was 7 oocysts/L (mean: 1.5 oocysts/L), and the highest cyst concentration was 4 cysts/L (mean: 0.6 cysts/L). The values of water turbidity were significantly higher on weekends than on weekdays, and were correlated with the number of bathers and concentration of C. parvum oocysts and G. lamblia cysts (P<0.04). The study demonstrated positive relationships between number of bathers and levels of waterborne C. parvum oocysts and G. lamblia cysts in recreational beach water. It is essential to test recreational waters for Cryptosporidium and Giardia when numbers of bathers are greatest, or limit the number of bathers in a recreational beach area.     

Microbiological studies of ethnic meat products of the Eastern Himalayas

Native microorganisms from some ethnic meat products of the Eastern Himalayas such as lang kargyong, yak kargyong, faak kargyong, lang satchu, yak satchu and suka ko masu were isolated and characterized. The bacterial isolates included Lactobacillus sake, Lactobacillus curvatus, Lactobacillus divergens, Lactobacillus carnis, Lactobacillus sanfrancisco, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus brevis, Enterococcus faecium, Leuconostoc mesenteroides, Pediococcus pentosaceous, Bacillus subtilis, Bacillus mycoides, Bacillus thuringiensis, Bacillus lentus and Bacillus licheniformis, Micrococcus and Staphylococcus. Yeast isolates included Debaryomyces hansenii, Debaryomyces polymorphus, Debaryomyces pseudopolymorphus, Pichia burtonii, Pichia anomala, Candida famata and the mould Rhizopus was also identified. Many of the LAB isolates demonstrated some antimicrobial activity, enzymatic activity and a few showed a high degree of hydrophobicity. None of the strains produced biogenic amines.