Iron oxide waste to clean arsenic-contaminated water.

Serious manifestations of arsenic toxicity in majority of human population consuming contaminated water has led to development of number of remedial methods including adsorption onto iron oxide based natural and synthetic materials. Iron oxide adsorbents generated as waste in industrial processes may be utilised for arsenic remediation. These adsorbents can be considered better in terms of least production cost as well as minimal environmental implications. Here, we studied arsenic removal from contaminated water using iron oxide wastes generated in pickling unit of a steel plant. The iron oxide obtained by steel pickling was subjected to controlled reduction in fluidised bed reactor using gaseous reductant producing magnetic iron oxide. Prior to adsorption studies, physicochemical characterisation of both the iron oxides was undertaken. This was followed by batch equilibrium and kinetics adsorption tests to investigate arsenic (V) removal properties. Several parameters such as time, pH, arsenic concentration, adsorbent dose etc were investigated using synthetic solutions. Arsenic affected ground water samples collected from West Bengal (India) were also tested using both iron oxide adsorbents. Experimental results showed more than 90% arsenic removal within 10 min, not depending on pH of water with appreciable loading (0.12-0.17 mg As/g) on both adsorbents. Presence of anions such as SO42-and PO43- adversely affected arsenic adsorption. While testing real ground water samples, initial arsenic level of 0.010–0.018 mg/L was brought down to 0.002–0.008 mg/L. Our study has established potential use of an industrial waste for the removal of arsenic (V) from water

How to realize a robust practical Majorana chain in a quantum dot-superconductor linear array

Semiconducting nanowires in proximity to superconductors are promising experimental systems for Majorana fermions, which may ultimately be used as building blocks for topological quantum computers. A serious challenge in the experimental realization of the Majorana fermions is the supression of topological superconductivity by disorder. We show that Majorana fermions protected by a robust topological gap can occur at the ends of a chain of quantum dots connected by s-wave superconductors. In the appropriate parameter regime, we establish that the quantum dot/superconductor system is equivalent to a 1D Kitaev chain, which can be tuned to be in a robust topological phase with Majorana end modes even in the case where the quantum dots and superconductors are both strongly disordered. Such a spin-orbit coupled quantum dot - s-wave superconductor array provides an ideal experimental platform for the observation of non-Abelian Majorana modes.Comment: 8 pages; 3 figures; version 2: Supplementary material updated to include more general proof for localized Majorana fermion

Tvorba ‘mekih’ čestica u Au+Au i Pb+Pb sudarima na visokim energijama

Production of low-pT (soft) hadronic particles in high energy collisions constitutes a significant corner of special interests and problems, as the perturbative quantum chromodynamics does not work in this region. We have probed here into the nature of the light particle production in two symmetric nuclear collisions at two neighbouring energies with the help of two non-standard models. The results are found to be in good agreement with data. Despite this, as the models applied here are not intended to provide deep insights into the actual physical processes involved in such collisions, the phenomenological bounds and constraints which cannot be remedied for the present continue to exist.Tvorba hadrona s malim pT (‘mekih’) u sudarima na visokim energijama čini važan problem i od posebnog je zanimanja budući da teorija smetnje kvantne kromodinamike u tom području nije uspješna. U ovom smo radu istražili prirodu tvorbe lakih čestica u dvama simetričnim nuklearnim sudarima na dvije bliske energije i primjenom dvaju nestandardnih modela. Ishodi računa su u dobrom skladu s podacima. Usprkos tome, ostaju fenomenološke granice i ograničenja koje se ne mogu popraviti jer primijenjeni modeli ne daju dublje razumijevanje u fizičke procese u takvim sudarima

A discussion of possible approaches to the integration of thermochemical storage systems in concentrating solar power plants

One of the most interesting perspectives for the development of concentrated solar power (CSP) is the storage of solar energy on a seasonal basis, intending to exploit the summer solar radiation in excess and use it in the winter months, thus stabilizing the yearly production and increasing the capacity factor of the plant. By using materials subject to reversible chemical reactions, and thus storing the thermal energy in the form of chemical energy, thermochemical storage systems can potentially serve to this purpose. The present work focuses on the identification of possible integration solutions between CSP plants and thermochemical systems for long-term energy storage, particularly for high-temperature systems such as central receiver plants. The analysis is restricted to storage systems potentially compatible with temperatures ranging from 700 to 1000 ◦C and using gases as heat transfer fluids. On the basis of the solar plant specifications, suitable reactive systems are identified and the process interfaces for the integration of solar plant/storage system/power block are discussed. The main operating conditions of the storage unit are defined for each considered case through process simulation

Prospects for the Search for a Standard Model Higgs Boson in ATLAS using Vector Boson Fusion

The potential for the discovery of a Standard Model Higgs boson in the mass range m_H < 2 m_Z in the vector boson fusion mode has been studied for the ATLAS experiment at the LHC. The characteristic signatures of additional jets in the forward regions of the detector and of low jet activity in the central region allow for an efficient background rejection. Analyses for the H -> WW and H -> tau tau decay modes have been performed using a realistic simulation of the expected detector performance. The results obtained demonstrate the large discovery potential in the H -> WW decay channel and the sensitivity to Higgs boson decays into tau-pairs in the low-mass region around 120 GeV.Comment: 20 pages, 13 ps figures, uses EPJ style fil

In vitro and in vivo efficacy of 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) on human melanoma

6-(7-Nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) is a powerful inhibitor of the glutathione transferase P1-1 (GSTP1-1) and causes the disruption of the complex between GSTP1-1 and c-Jun N-terminal Kinase (JNK). This induces JNK activation and apoptosis in tumour cells. in the present work we assess the in vitro and in vivo effectiveness of NBDHEX on two human melanoma cell lines, Me501 and A375. NBDHEX shows IC50 values in the low micromolar range (IC50 of 1.2 +/- 0.1 mu M and 2.0 +/- 0.2 mu M for Me501 and A375, respectively) and is over 100 times more cytotoxic to these cell lines than temozolomide. Apoptosis is observed in Me501 cells within 3 h of the addition of NBDHEX, while in A375 cells the apoptotic event is rather late, and is preceded by a G2/M phase arrest. In both melanoma cell lines, INK activity is required for the ability of NBDHEX to trigger apoptosis, confirming that the JNK pathway is an important therapeutic target for this tumour. NBDHEX is also both effective and well tolerated in in vivo tumour models. A tumour inhibition of 70% is observed in vivo against Me501 human melanoma and a similar result is obtained on A375 model, with 63% of turnout inhibition. These findings indicate that the activation of the JNK pathway, through a selective GSTP1-1 targeting, could prove to be a promising new strategy for treating melanoma, which responds poorly to conventional therapies. (C) 2009 Elsevier Ltd. All rights reserved