Electron tunneling experiments on La0.7A0.3MnO3 (A=Ca, Sr, Ba)

Journal ArticleTunneling conductance measurements of the electronic density of states of perovskite manganates, La0.7A0.3MnO3 are reported. Tunneling data of all the samples show a zero-bias anomaly with a minimum in the density of states at the Fermi level. This behavior is interpreted as arising from strong electronic correlations

Metal-insulator transition in La0.7Sr0.3Mn1-xFexO3

Journal ArticleWe report the effect of Fe doping at the Mn site in La0.7Sr0.3MnO3 oxides. We find that the doping of Fe does not cause any structural change, but the electrical transport in the system is strongly affected. The parent compound La0.7Sr0.3MnO3 shows a resistivity peak at T=Tp (365 K) and behaves as a ferromagnetic metal at low temperature. Double exchange (DE) interaction between Mn3+ and Mn4+ is understood to be the cause of ferromagnetism and metallicity of the material. As Fe is doped into the system a depletion in the number of hopping electrons occurs and consequently the DE interaction becomes weak, however, as long as x≤0.2 the system shows metallic behavior at low temperatures. For higher Fe doping the system becomes insulating throughout the whole temperature range. Electron tunneling conductance measurements show that the density of states of metallic samples exhibits a dip at EF. As the value of x increases the dip deepens and finally at x=0.25 a gap opens up at the Fermi level

Cross pinning versus lateral pinning in type III supracondylar fracture: a retrospective analysis

Background: The commonly accepted treatment of type III supracondylar fractures of humerus in children is closed reduction percutaneous pinning (CRPP). There is a long debate over stability and complications associated with cross and lateral pinning. The present study compares the functional outcome and complications of both pinning techniques.Methods: A retrospective analysis of results with regard to ulnar nerve injury, carrying angle and range of movements was made in 27 children with lateral pinning and 28 children with crossed pinning was done in our institution. Functional outcome was graded according to Flynn’s criteria and loss of reduction by Skagg’s criteria.Results: There was no statistically significant difference with regard to functional outcome and loss of reduction between the two groups. Iatrogenic ulnar nerve injury (IUNI) occurred in three cases (11%) after crossed pinning in which two had significant palsy, which recovered by three months and the other had only  transient paraesthesia.Conclusions: Lateral pinning technique is reliably safe method in terms of stability as it avoids IUNI, we recommend it

An Evaluation of Sonication Pretreatment for Enhancing Saccharification of Brewers’ Spent Grain

This paper deals with the investigation of ultrasound (US) pretreatment of brewer’s spent grain (BSG) as ameans of releasing fermentable sugars, and the subsequent production of ethanol from this lignocellu-losic biomass. Using response surface methodology (RSM), the influence of US power, time, temperatureand biomass loading on fermentable sugar yield from BSG was studied. The optimal conditions werefound to be 20% US power, 60 min, 26.3°C, and 17.3% w/v of biomass in water. Under these conditions,an approximate 2.1-fold increase in reducing sugar yield (325 ± 6 mg/g of biomass) was achieved, relativeto untreated BSG (151.1 ± 10 mg/g of biomass). In contrast to acid or alkaline pretreatment approaches,the use of water obviated the need for neutralization for the recovery of sugars. The characterization ofnative and pretreated BSG was performed by HPLC, FTIR, SEM and DSC. Fermentation studies usingS.cerevisiaegrowing on pretreated BSG resulted in a conversion of 66% of the total sugar content inintoethanol with an ethanol content of 17.73 ± 2 g/ 100 g of pretreated BSG. These results suggest that ultra-sound pretreatment is a promising technology for increased valorization of BSG as a feedstock for produc-tion of bioethanol, and points ton the need for further work in this are

A Review of Alternative Proteins For Vegan Diets: Sources, Physico-Chemical Properties, Nutritional Equivalency, and Consumer Acceptance

Alternate proteins are gaining popularity as a more sustainable and environmentally friendly alternative to animal-based proteins. These proteins are often considered healthier and are suitable for people following a vegetarian or vegan diet. Alternative proteins can be recovered from natural sources like legumes, grains, nuts, and seeds, while single cell proteins (mycoproteins), and algal proteins are being developed using cutting-edge technology to grow fungus, yeast and algal cells in a controlled environment, creating a more sustainable source of protein. Although, the demand for alternative protein products is increasing, there still happens to be a large gap in use among the general consumers mainly stemming from its lower bioavailability, lack of nutritional equivalency and reduced digestibility compared to animal proteins. The focus of the review is to emphasize on various sources and technologies for recovering alternative proteins for vegan diets. The review discusses physicochemical properties of alternative proteins and emphasise on the role of various processing technologies that can change the digestibility and bioavailability of these proteins. It further accentuates the nutritional equivalency and environmental sustainability of alternative protein against the conventional proteins from animals. The food laws surrounding alternative proteins as well as the commercial potential and consumer acceptance of alternative protein products are also highlighted. Finally, key challenges to improve the consumer acceptability and market value of plant-based proteins would be in achieving nutrient equivalency and enhance bioavailability and digestibility while maintaining the same physicochemical properties, taste, texture, as animal proteins, has also been highlighted

Signatures of Spin Glass Freezing in NiO Nanoparticles

We present a detailed study of the magnetic properties of sol-gel prepared nickel oxide nanoparticles of different sizes. We report various measurements such as frequency, field and temperature dependence of ac susceptibility, temperature and field dependence of dc magnetization and time decay of thermoremanent magnetization. Our results and analysis show that the system behaves as a spin glass.Comment: 8 pages, 9 figure

An evaluation of sonication pretreatment for enhancing saccharification of brewers' spent grain

peer-reviewedThis paper deals with the investigation of ultrasound (US) pretreatment of brewer’s spent grain (BSG) as a means of releasing fermentable sugars, and the subsequent production of ethanol from this lignocellulosic biomass. Using response surface methodology (RSM), the influence of US power, time, temperature and biomass loading on fermentable sugar yield from BSG was studied. The optimal conditions were found to be 20% US power, 60 min, 26.3 °C, and 17.3% w/v of biomass in water. Under these conditions, an approximate 2.1-fold increase in reducing sugar yield (325 ± 6 mg/g of biomass) was achieved, relative to untreated BSG (151.1 ± 10 mg/g of biomass). In contrast to acid or alkaline pretreatment approaches, the use of water obviated the need for neutralization for the recovery of sugars. The characterization of native and pretreated BSG was performed by HPLC, FTIR, SEM and DSC. Fermentation studies using S. cerevisiae growing on pretreated BSG resulted in a conversion of 66% of the total sugar content ininto ethanol with an ethanol content of 17.73 ± 2 g/ 100 g of pretreated BSG. These results suggest that ultrasound pretreatment is a promising technology for increased valorization of BSG as a feedstock for production of bioethanol, and points ton the need for further work in this area