New lithium-ion conductors based on the NASICON structure

Lithium-ion conduction in mixed-metal phosphates, LiMVMIII(PO4)3 [MV=Nb, Ta; MIII=Al, Cr, Fe], possessing the rhombohedral (R3c) NASICON structure has been investigated. Among the phosphates investigated, LiTaAl(PO4)3 exhibits the highest conductivity, σ ≈ 1.0×10-2 S cm-1 at 350°C (Ea=0.47 eV), comparable to the conductivity of LiTi2(PO4)3. Unlike LiTi2(PO4)3 which contains lithium-reducible TiIV, LiTaAl(PO4)3 contains stable TaV and AlIII oxidation states and hence deserves further attention towards tailoring new lithium-ion conductors for application as electrolytes in solid state lithium batteries

Unipolar resistive switching in cobalt titanate thin films

We report giant resistive switching of an order of 104, long-time charge retention characteristics up to 104 s, non-overlapping SET and RESET voltages, ohmic in low resistance state (LRS) and space charge limited current (SCLC) mechanism in high resistance state (HRS) properties in polycrystalline perovskite Cobalt Titanate (CoTiO3 ~ CTO) thin films. Impedance spectroscopy study was carried out for both LRS and HRS states which illustrates that only bulk resistance changes after resistance switching, however, there is a small change (<10% which is in pF range) in the bulk capacitance value in both states. These results suggest that in LRS state current filaments break the capacitor in many small capacitors in a parallel configuration which in turn provides the same capacitance in both states even there was 90 degree changes in phase-angle and an order of change in the tangent loss.Comment: 7 pages, 4 figure

Adverse effects of antiretroviral treatment at a tertiary care hospital in India: a prospective observational study

Background: Data on adverse drug reactions (ADRs) related to antiretroviral (ARV) use in public health practice are few indicating the need for antiretroviral therapy (ART) safety surveillance in clinical care.Methods: 143 patients on ART were studied prospectively over a period of two years. All patients were asked to visit the clinic if they developed any symptoms or on a monthly basis. They were screened clinically and investigated suitably for any ADRs.Results: 143 HIV positive patients were analyzed. At least one ADR was seen in 87 (60.83%) subjects. The most common ADR observed was peripheral neuropathy in 54 (37.76%) patients, followed by lipodystrophy (13.98%), anemia (10.48%) and hyperlipidemia (6.29%). Patients with peripheral neuropathy and lipodystrophy were mainly on stavudine based regimes, while patient with anemia and hyperlipidemia were on zidovudine based regimes. Conclusions: In spite of high ADRs, highly active antiretroviral therapy (HAART) is the only answer to HIV/AIDS. To optimize adherence and thus, efficacy of ART, clinicians must focus on preventing adverse effects whenever possible, and distinguish those that are self-limited from those that are potentially serious

Petrographic investigation of selected natural cokes from Damodar Valley coalfields

The natural coke is a kind of fossil fuel and its reserves are scattered in almost coalfields covering approx. 2600 Km 2. In Indian coalfields, the igneous intrusion varies, causing regional in-situ burning of coal seams. The intrusion process itself is quite complex and does not follow any fixed trend everywhere. The chemical composition of the intrusion also varies from place to place. Petrographic, physical and chemical characterizations of some selected natural coke samples of Damodar Valley coalfields were done. The comprehensive study on above samples helped a lot in differentiation of natural cokes, slightly heat affected coal and normal coals obtained after washability at different specific gravities. The yield of the samples after washability varied from sample to sample. Through petrographic studies by microscopy, an effort has been made to decipher the new classification schemes for microtextures and microstructures of natural coke, which are generated through in-situ carbonisation of coal seams. Isotropic, anisotropic components and mineral matters were differentiated. Some selected natural coke fractions were explored for value addition in different studies. The study was helpful in establishing industrial use of natural coke in Power, Cement and Carbon Artifact industry

Effect of Arbuscular Mycorrhize on Growth and Productivity of \u3cem\u3eStylosanthes seabrana\u3c/em\u3e

Stylosanthes seabrana, an important range legume was introduced in India in the year 1998 through ACIAR-ICAR joint project. It has given good results under agroforestry/silvopastoral systems and can be grown as sole pasture crop or along with compatible grasses/legumes on a variety of soils. For its year round production, intensive cutting approach is generally employed. Under such conditions, plant demands large amount of soil nutrients for better productivity, which are generally applied as inorganic fertilizers (Chandra et al., 2006). In soils with low nutrient contents especially phosphorus (P), large amount of phosphatic fertilizers are required for establishment and growth of legumes. P is often a growth-limiting factor for plant growth and legumes are poor scavengers of P. In soils, P may present in sufficient amounts but much of it is poorly available to plants because of less solubility of phosphates of calcium, aluminum and iron. Arbuscular mycorrhizae (AM), an important soil microorganism mobilize phosphates and make available to the plants, which indirectly increases their growth (Jha et al., 2012). AM fungi have proved their usefulness in plant production, How even the efficiency of AM inoculants can be affected by properties and texture of the potting substrates (Herrera-Peraza et al., 2011). Since, reports on effect of AM inoculations on growth and productivity of S. seabrana are very scarce in literature; hence, present study was carried out to identify the suitable AM inoculants for S. seabrana

Ferroelectric Capped Magnetization in Multiferroic PZT/LSMO Tunnel Junctions

Self-poled ultra-thin ferroelectric PbZr0.52Ti0.48O3 (PZT) (5 and 7 nm) films have been grown by pulsed laser deposition technique on ferromagnetic La0.67Sr0.33MnO3 (LSMO) (30 nm) to check the effect of polar capping on magnetization for ferroelectric tunnel junction (FTJ) devices. PZT/LSMO heterostructures with thick polar PZT (7 nm) capping show nearly 100% enhancement in magnetization compared with thin polar PZT (5 nm) films, probably due to excess hole transfer from the ferroelectric to the ferromagnetic layers. Core-level X-ray photoelectron spectroscopy studies revealed the presence of larger Mn 3s exchange splitting and higher Mn3+/Mn4+ ion ratio in the LMSO with 7 nm polar capping.Comment: 17 pages, 5 figure

Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor

We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H2sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanoparticles were observed to show better hydrogen sensing response than the sputtered palladium thin films. The demonstration of size dependent room temperature H2sensing paves the ways to fabricate the room temperature metallic and metal–metal oxide semiconductor sensor by tuning the size of metal catalyst in mixed systems. H2sensing by the Pd nanostructures is attributed to the chemical and electronic sensitization mechanisms