Limits on stable iron in Type \,Ia supernovae from NIR spectroscopy

We obtained optical and near-infrared spectra of Type$\,$Ia supernovae (SNe$\,$Ia) at epochs ranging from 224 to 496 days after the explosion. The spectra show emission lines from forbidden transitions of singly ionised iron and cobalt atoms. We used non-local thermodynamic equilibrium (NLTE) modelling of the first and second ionisation stages of iron, nickel, and cobalt to fit the spectra using a sampling algorithm allowing us to probe a broad parameter space. We derive velocity shifts, line widths, and abundance ratios for iron and cobalt. The measured line widths and velocity shifts of the singly ionised ions suggest a shared emitting region. Our data are fully compatible with radioactive $^{56}$Ni decay as the origin for cobalt and iron. We compare the measured abundance ratios of iron and cobalt to theoretical predictions of various SN$\,$Ia explosion models. These models include, in addition to $^{56}$Ni, different amounts of $^{57}$Ni and stable $^{54,56}$Fe. We can exclude models that produced only $^{54,56}$Fe or only $^{57}$Ni in addition to $^{56}$Ni. If we consider a model that has $^{56}$Ni, $^{57}$Ni, and $^{54,56}$Fe then our data imply that these ratios are $^{54,56}$Fe / $^{56}$Ni $=0.272\pm0.086$ and $^{57}$Ni / $^{56}$Ni $=0.032\pm0.011$.Comment: 10 pages, 7 figures, Accepted for publication in A&

Nebular spectroscopy of SN 2014J: Detection of stable nickel in near infrared spectra

We present near infrared (NIR) spectroscopy of the nearby supernova 2014J obtained $\sim$450 d after explosion. We detect the [Ni II] 1.939 $\mu$m line in the spectra indicating the presence of stable $^{58}$Ni in the ejecta. The stable nickel is not centrally concentrated but rather distributed as the iron. The spectra are dominated by forbidden [Fe II] and [Co II] lines. We use lines, in the NIR spectra, arising from the same upper energy levels to place constraints on the extinction from host galaxy dust. We find that that our data are in agreement with the high $A_V$ and low $R_V$ found in earlier studies from data near maximum light. Using a $^{56}$Ni mass prior from near maximum light $\gamma$-ray observations, we find $\sim$0.05 M$_\odot$ of stable nickel to be present in the ejecta. We find that the iron group features are redshifted from the host galaxy rest frame by $\sim$600 km s$^{-1}$.Comment: 6 pages, 4 figures, submitted to A&

ZnO anchored graphene hydrophobic nanocomposite-based bulk heterojunction solar cells showing enhanced short-circuit current

Hydrophobic and surfactant-free ZnO nanoparticles and ZnO decorated graphene nanocomposite (Z@G) with narrow and uniform size distribution were synthesized by a time-efficient microwave-assisted hydrothermal reaction that can be used specifically for application in hybrid photovoltaics. The synthesized ZnO nanoparticles and Z@G nanocomposite showed stable and clear dispersion in chloroform and methanol (with volume ratio of 9 : 1) and chloroform and ethanol (volume ratio 9 : 1). Being hydrophobic, these inorganic samples blend very well with organic polymer solution in chlorobenzene, which is a prerequisite to cast smooth and undisrupted film for hybrid solar cell application. The introduction of these hydrophobic nanoparticles into PCPDTBT: PCBM-based bulk-heterojunction polymer solar cells resulted in significant improvement in solar cell J-V characteristics with enhancement in open circuit voltage (VOC), short circuit current density (JSC) and thereby overall improvement in cell efficiency. With the optimization of the weight ratio of polymer, fullerene and synthesized ZnO nanoparticles/Z@G nanocomposite, the power conversion efficiencies 1.76% and 3.65% were achieved

Economic impact of dissemination of management strategies for sucking insect pests on transgenic cotton in Punjab, India

Integrated pest management (IPM) strategies for the management of sucking insect pests were disseminated in 36 villages of three districts of Punjab during 2008 to 2010. Adoption of IPM strategies led to reduction in the population of jassid, whitefly and mealybug in IPM villages. Mean population of jassid was 0.62 and 1.60 nymphs per three leaves, whitefly 1.11 and 2.53 adults per three leaves and mealybug 0.53 and 1.03 per 2.5 cm of central shoot in IPM and non-IPM villages, respectively. Mean population of spiders, chrysoperla, coccinellids and predatory bugs was 0.65, 0.13, 0.15 and 0.04 in IPM villages and 0.29, 0.09, 0.06 and 0.00 per plant in non-IPM villages, respectively. IPM strategies resulted in the 47.69 and 50.56 per cent reduction in number of spray and cost of spray in IPM villages over non-IPM villages. The average cost of cultivation was Rs. 21324 ha−1 in IPM villages, as compared to non-IPM villages (Rs. 23774.67 ha−1). Average seed cotton yield in IPM villages was 2333 kg ha−1 in comparison to non-IPM villages (1959.67 kg ha−1) and average net return in IPM villages was Rs. 57194 ha−1, which was Rs. 15709 more than non-IPM villages

Measurement of the analyzing power of proton-carbon elastic scattering in the CNI region at RHIC

The single transverse spin asymmetry, A_N, of the p-carbon elastic scattering process in the Coulomb Nuclear Interference (CNI) region was measured using an ultra thin carbon target and polarized proton beam in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). In 2004, data were collected to calibrate the p-carbon process at two RHIC energies (24 GeV, 100 GeV). A_N was obtained as a function of momentum transfer -t. The results were fit with theoretical models which allow us to assess the contribution from a hadronic spin flip amplitude.Comment: Contribution to the proceedings of the 16th International Spin Physics Symposium, spin2004 (Trieste

Vitamin D status and associated genetic polymorphisms in a cohort of UK children with non -alcoholic fatty liver disease

Background: Vitamin D deficiency has been associated with non-alcoholic fatty liver disease (NAFLD). However, the role of polymorphisms determining vitamin D status remains unknown. Objectives: To determine in UK children with biopsy-proven NAFLD: (i) vitamin D status throughout a 12-month period; (ii) interactions between key vitamin D-related genetic variants (NADSYN1/DHCR7, VDR, GC, CYP2R1) and disease severity. Methods: In 103 pediatric patients with NAFLD, serum 25-hydroxyvitamin D (25OHD) levels and genotypes were determined contemporaneously to liver biopsy and examined in relation to NAFLD activity score and fibrosis stage. Results: Only 19.2% of children had adequate vitamin D status; most had mean 25OHD levels considered deficient (<25nmol/l, 25.5%) or insufficient (<50nmol/l, 55.3%). Patients had significantly lower 25OHD levels in winter months (95%CI: 22.7-31.2nmol/l) when compared to spring (30.5-42.1nmol/l; P=0.0089), summer (36.3-47.2nmol/l; P<0.0001) and autumn (34.2-47.5nmol/l; P=0.0003). Polymorphisms in the NADSYN1/DHCR7 (rs3829251, rs12785878), and VDR (rs2228570) genes were independently associated with increased steatosis; while a GC variant (rs4588) was associated with increased inflammation in liver biopsies. Conclusions: Children with NAFLD in the UK have particularly low winter vitamin D status; with vitamin D insufficiency prevalent throughout the year. Polymorphisms in the vitamin D metabolic pathway are associated with histological severity of pediatric NAFLD

Anticonvulsant effects of aerial parts of Passiflora incarnata extract in mice: involvement of benzodiazepine and opioid receptors

<p>Abstract</p> <p>Background</p> <p>Passion flower (<it>Passiflora incarnata</it>) is used in traditional medicine of Europe and South America to treat anxiety, insomnia and seizure. Recently, it has shown antianxiety and sedative effects in human.</p> <p>Methods</p> <p>In this study, anticonvulsant effects of hydro- alcoholic extract of Passiflora, Pasipay, were examined by using pentylentetrazole model (PTZ) on mice. Pasipay, diazepam, and normal saline were injected intraperitoneally at the doses 0.4–0.05 mg/kg, 0.5–1 mg/kg and 10 ml/kg respectively 30 minutes before PTZ (90 mg/kg, i.p). The time taken before the onset of clonic convulsions, the duration of colonic convulsions, and the percentage of seizure and mortality protection were recorded. For investigating the mechanism of Pasipay, flumazenil (2 mg/kg, i.p) and naloxone (5 mg/kg, i.p) were also injected 5 minutes before Pasipay.</p> <p>Results</p> <p>An ED₅₀value of Pasipay in the PTZ model was 0.23 mg/kg (%95 CL: 0.156, 0.342). Pasipay at the dose of 0.4 mg/kg prolonged the onset time of seizure and decreased the duration of seizures compared to saline group (p < 0.001). At the dose of 0.4 mg/kg, seizure and mortality protection percent were 100%. Flumazenil and naloxone could suppress anticonvulsant effects of Pasipay.</p> <p>Conclusion</p> <p>It seems that Pasipay could be useful for treatment absence seizure and these effects may be related to effect of it on GABAergic and opioid systems. More studies are needed in order to investigate its exact mechanism.</p

Disk-Jet Connection in Cygnus X-3

We present the results of a detailed correlation study between the soft X-ray, hard X-ray, and radio emission (obtained from RXTE ASM, BATSE, and GBI observations, respectively) of the bright radio emitting Galactic X-ray binary Cygnus X-3. We detect a very strong positive correlation between the soft X-ray and radio emission during the low-hard and minor flaring periods of the source, and an anti-correlation between the soft and hard X-ray emissions. We present statistical arguments to suggest that the anti-correlation between the radio and hard X-ray emission, reported earlier, is primarily due to their correlation and anti-correlation, respectively, with the soft X-ray emission. We make a wide band X-ray spectral study using the pointed RXTE observations and detect a pivotal behaviour in the X-ray spectrum. We argue that this X-ray spectral pivoting is responsible for the anti-correlation between the soft and hard X-ray emissions. The strong correlation between the soft X-ray and radio emission suggests a close link between the accreting mechanism, plasma cloud surrounding the compact object and the radio emission.Comment: Accepted in A&A Letters. Major revioson of discussion, minor revision of tables and figure

Microwave shielding properties of Co/Ni attached to single walled carbon nanotubes

Cobalt/nickel nanoparticles attached to single-walled carbon nanotubes (Co/Ni@SWCNTs) were prepared by dc-arc discharge technique. Co/Ni@SWCNTs were characterized by scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), Raman spectroscopy and energy dispersive X-ray analysis techniques. HRTEM results confirmed attachment of magnetic nanoparticles onto SWCNTs having 1.2 nm diameter. A microwave shielding effectiveness value of 24 dB (blocking >99% radiation) by a 1.5 mm thick sample in the frequency range of 12.4-18 GHz was observed. In order to understand the mechanism of shielding, dielectric andmagnetic attributes of the shielding effectiveness of Co/Ni@SWCNTs have been evaluated. Eddy currents and natural resonances due to the presence of magnetic nanoparticles, electronic polarization and their relaxation, interfacial polarization and unique composition of the shield contributed significantly in achieving good shielding effectiveness. The observed microwave shielding crossed the limit required for commercial applications which suggests that these nanocomposites are promising microwave shielding materials in the Ku band