Mechanism of Cyanide Toxicity and Efficacy of its Antidotes

This paper attempts to review the various antidotes available for countering cyanide threat in the light of the toxicity associated with it. It also critically evaluates the drawbacks and advantages of these antidotes for their therapeutic and/or prophylactic utility. The physico-chemical properties of hydrogen cyanide which make it a chemical warfare agent have also been highlighted. In an attempt to make the complex chemical and biological processes understandable, the chemical structures of the antidotes have been included and simple mechanistic pathways have been used to show the role of antidotes in activating the inhibited enzymes

Effect of magnetic field on the phase transition in a dusty plasma

The formation of self-consistent crystalline structure is a well-known phenomenon in complex plasmas. In most experiments the pressure and rf power are the main controlling parameters in determining the phase of the system. We have studied the effect of externally applied magnetic field on the configuration of plasma crystals, suspended in the sheath of a radio-frequency discharge using the Magnetized Dusty Plasma Experiment (MDPX) device. Experiments are performed at a fixed pressure and rf power where a crystalline structure is formed within a confining ring. The magnetic field is then increased from 0 to 1.28 T. We report on the breakdown of the crystalline structure with increasing magnetic field. The magnetic field affects the dynamics of the plasma particles and first leads to a rotation of the crystal. At higher magnetic field, there is a radial variation (shear) in the angular velocity of the moving particles which we believe leads to the melting of the crystal. This melting is confirmed by evaluating the variation of the pair correlation function as a function of magnetic field.Comment: 9 pages, 5 figure

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

TSUNAMIGENIC SOURCES IN THE INDIAN OCEAN

Based on an assessment of the repeat periods of great earthquakes from past seismicity, convergence rates and paleoseismological results, possible future source zones of tsunami generating earthquakes in the Indian Ocean (possible seismic gap areas) are identified along subduction zones and zones of compression. Central Sumatra, Java, Makran coast, Indus Delta, Kutch-Saurashtra, Bangladesh and southern Myanmar are identified as possible source zones of earthquakes in near future which might cause tsunamis in the Indian Ocean, and in particular, that could affect India. The Sunda Arc (covering Sumatra and Java) subduction zone, situated on the eastern side of the Indian Ocean, is one of the most active plate margins in the world that generates frequent great earthquakes, volcanic eruptions and tsunamis. The Andaman- Nicobar group of islands is also a seismically active zone that generates frequent earthquakes. However, northern Sumatra and Andaman-Nicobar regions are assessed to be probably free from great earthquakes (M!8.0) for a few decades due to occurrence of 2004 Mw 9.3 and 2005 Mw 8.7 earthquakes. The Krakatau volcanic eruptions have caused large tsunamis in the past. This volcano and a few others situated on the ocean bed can cause large tsunamis in the future. List of past tsunamis generated due to earthquakes/volcanic eruptions that affected the Indian region and vicinity in the Indian Ocean are also presented

Kinetics of Surface Enrichment: A Molecular Dynamics Study

We use molecular dynamics (MD) to study the kinetics of surface enrichment (SE) in a stable homogeneous mixture (AB), placed in contact with a surface which preferentially attracts A. The SE profiles show a characteristic double-exponential behavior with two length scales: \xi_-, which rapidly saturates to its equilibrium value, and \xi_+, which diverges as a power-law with time (\xi_+ \sim t^\theta). We find that hydrodynamic effects result in a crossover of the growth exponent from \theta \simeq 0.5 to \theta \simeq 1.0. There is also a corresponding crossover in the growth dynamics of the SE-layer thickness.Comment: 20 pages, 6 figures, Published in J. Chem. Phys. (Research Highlights

Flux jumps, Second Magnetization Peak anomaly and the Peak Effect phenomenon in single crystals of YNi2B2CYNi_2B_2C and LuNi2B2CLuNi_2B_2C

We present magnetization measurements in single crystals of the tetragonal $YNi_2B_2C$ compound, which exhibit the phenomenon of peak effect as well as the second magnetization peak anomaly for H $>$ 0.5T (H $||$ c). At the lower field (50mT $<$ H $<$ 200mT), we have observed the presence of flux jumps, which seem to relate to a structural change in the local symmetry of the flux line lattice (a first order re-orientation transition across a local field in some parts of the sample, in the range of 100mT to 150mT). These flux jumps are also observed in a single crystal of $LuNi_2B_2C$ for H $||$ c in the field region from 2 mT to 25 mT, which are compatible with the occurrence of a re-orientation transition at a lower field in a cleaner crystal of this compound, as compared to those of $YNi_2B_2C$. Vortex phase diagrams drawn for H $||$ c in $LuNi_2B_2C$ and $YNi_2B_2C$ show that the ordered elastic glass phase spans a larger part of (H, T) space in the former as compared to latter, thereby, reaffirming the difference in the relative purity of the two samples.Comment: 11 pages, 14 figure

Moving Towards the Second Generation of Lignocellulosic Biorefineries in the EU: Drivers, Challenges, and Opportunities

The EU aims to achieve a variety of ambitious climate change mitigation and sustainable development goals by 2030. To deliver on this aim, the European Commission (EC) launched the bioeconomy strategy in 2012. At the heart of this policy is the concept of the sustainable Biorefinery, which is based centrally on a cost-effective conversion of lignocellulosic biomass into bioenergy and bioproducts. The first generation of biorefineries was based on utilization of edible food crops, which raised a “food vs. fuel” debate and questionable sustainability issues. To overcome this, lignocellulosic feedstock options currently being pursued range from non-food crops to agroforestry residues and wastes. Notwithstanding this, advanced biorefining is still an emerging sector, with unanswered questions relating to the choice of feedstocks, cost-effective lignocellulosic pretreatment, and identification of viable end products that will lead to sustainable development of this industry. Therefore, this review aims to provide a critical update on the possible future directions of this sector, with an emphasis on its role in the future European bioeconomy, against a background of global developments

Moving Towards the Second Generation of Lignocellulosic Biorefineries in the EU: Drivers, Challenges, and Opportunities

The EU aims to achieve a variety of ambitious climate change mitigation and sustainable development goals by 2030. To deliver on this aim, the European Commission (EC) launched the bioeconomy strategy in 2012. At the heart of this policy is the concept of the sustainable Biorefinery, which is based centrally on a cost-effective conversion of lignocellulosic biomass into bioenergy and bioproducts. The first generation of biorefineries was based on utilization of edible food crops, which raised a “food vs. fuel” debate and questionable sustainability issues. To overcome this, lignocellulosic feedstock options currently being pursued range from non-food crops to agroforestry residues and wastes. Notwithstanding this, advanced biorefining is still an emerging sector, with unanswered questions relating to the choice of feedstocks, cost-effective lignocellulosic pretreatment, and identification of viable end products that will lead to sustainable development of this industry. Therefore, this review aims to provide a critical update on the possible future directions of this sector, with an emphasis on its role in the future European bioeconomy, against a background of global developments

Investigation of the Dzyaloshinskii-Moriya interaction and room temperature skyrmions in W/CoFeB/MgO thin films and microwires

Recent studies have shown that material structures, which lack structural inversion symmetry and have high spin-orbit coupling can exhibit chiral magnetic textures and skyrmions which could be a key component for next generation storage devices. The Dzyaloshinskii-Moriya Interaction (DMI) that stabilizes skyrmions is an anti-symmetric exchange interaction favoring non-collinear orientation of neighboring spins. It has been shown that material systems with high DMI can lead to very efficient domain wall and skyrmion motion by spin-orbit torques. To engineer such devices, it is important to quantify the DMI for a given material system. Here we extract the DMI at the Heavy Metal (HM) /Ferromagnet (FM) interface using two complementary measurement schemes namely asymmetric domain wall motion and the magnetic stripe annihilation. By using the two different measurement schemes, we find for W(5 nm)/Co20Fe60B20(0.6 nm)/MgO(2 nm) the DMI to be 0.68 +/- 0.05 mJ/m2 and 0.73 +/- 0.5 mJ/m2, respectively. Furthermore, we show that this DMI stabilizes skyrmions at room temperature and that there is a strong dependence of the DMI on the relative composition of the CoFeB alloy. Finally we optimize the layers and the interfaces using different growth conditions and demonstrate that a higher deposition rate leads to a more uniform film with reduced pinning and skyrmions that can be manipulated by Spin-Orbit Torques