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).     

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...     

Photofunctions in Hybrid Systems of Schiff Base Metal Complexes and Metal or Semiconductor (Nano)Materials

Composite materials very often provide new catalytic, optical or other physicochemical properties not observed for each component separately. Photofunctions in hybrid systems are an interesting topic of great importance for industry. This review presents the recent advances, trends and possible applications of photofunctions of hybrid systems composed of Schiff base metal complexes and metal or semiconductor (nano)materials. We focus on photocatalysis, sensitization in solar cells (DSSC—dye sensitized solar cell), ligand-induced chirality and applications in environmental protection for Cr(VI) to Cr(III) reduction, in cosmetology as sunscreens, in real-time visualization of cellular processes, in bio-labeling, and in light activated prodrug applications.     

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.     

Instrumental Textural Perception of Food and Comparative Biomaterials

Exposing an extruded corn snack, an extruded biodegradable packing material, carrots, and wood chip cork to relative humidity conditions ranging from 29.5 to 97.5% changed their moisture content and affected the respective internal structures. The extruded corn snack and extruded biodegradable packing material specimens evaluated after 24 h, absorbed moisture and lost crispness. Carrot and cork specimens were evaluated after 48 h; carrots lost moisture, became softer, and decreased in hardness from 55.02 ± 7.59 to 23.6 ± 8.6 N, while cork specimens were unchanged. For all products, loss of moisture increased surface roughness. Increasing moisture amplified turgidity and strength in extruded biodegradable packing material, decreased crispness in extruded corn snack, and stiffness in carrot, but produced no changes in the wood chip cork.     

Effect of surface functional groups on hydrogen adsorption properties of Pd dispersed reduced graphene oxide

Pd/reduced graphene oxide (Pd-RGO) composites were successfully prepared from graphite and PdCl₂ precursors using wet impregnation and reverse micro emulsion methods. From hydrogen adsorption studies it is confirmed that spillover of hydrogen from Pd to graphene layers occurs at room temperature. However, at low temperatures there is negligible spillover effect and this is explained based on lower kinetic energy available with hydrogen atoms to overcome the activation barrier involved in diffusion. Detailed ¹³C MAS NMR and Raman spectroscopic studies confirmed that small amounts of structural units (functional groups) like carboxylate and polyacetylenic linkages are retained in Pd-RGO samples prepared by wet impregnation and reverse micro-emulsion methods, respectively. Such structural moieties facilitate the atomic scale mixing of Pd with the graphene layers thereby improving the spillover efficiency.     

Information sharing and exchange in the context of product lifecycle management: Role of standards

This paper introduces a model of the information flows in Product Life cycle Management (PLM), serving as the basis for understanding the role of standards in PLM support systems. Support of PLM requires a set of complementary and interoperable standards that cover the full range of aspects of the products’ life cycle. The paper identifies a typology of standards relevant to PLM support that addresses the hierarchy of existing and evolving standards and their usage and identifies a suite of standards supporting the exchange of product, process, operations and supply chain information. A case study illustrating the use of PLM standards in a large organization is presented. The potential role of harmonization among PLM support standards is described and a proposal is made for using open standards and open source models for this important activity.