Cochin University of Science and Technology

About: Cochin University of Science and Technology is a education organization based out in Kochi, Kerala, India. It is known for research contribution in the topics: Thin film & Natural rubber. The organization has 5382 authors who have published 7690 publications receiving 103827 citations. The organization is also known as: CUSAT & Cochin University.

Blunted ventral striatal responses to anticipated rewards foreshadow problematic drug use in novelty-seeking adolescents

Abstract: Novelty-seeking tendencies in adolescents may promote innovation as well as problematic impulsive behaviour, including drug abuse. Previous research has not clarified whether neural hyper- or hypo-responsiveness to anticipated rewards promotes vulnerability in these individuals. Here we use a longitudinal design to track 144 novelty-seeking adolescents at age 14 and 16 to determine whether neural activity in response to anticipated rewards predicts problematic drug use. We find that diminished BOLD activity in mesolimbic (ventral striatal and midbrain) and prefrontal cortical (dorsolateral prefrontal cortex) regions during reward anticipation at age 14 predicts problematic drug use at age 16. Lower psychometric conscientiousness and steeper discounting of future rewards at age 14 also predicts problematic drug use at age 16, but the neural responses independently predict more variance than psychometric measures. Together, these findings suggest that diminished neural responses to anticipated rewards in novelty-seeking adolescents may increase vulnerability to future problematic drug use.

Evaluation of a.c. conductivity of rubber ferrite composites from dielectric measurements

Abstract: The effect of frequency, composition and temperature on the a.c. electrical conductivity were studied for the ceramic, Ni1−xZnxFe2O4, as well as the filler (Ni1−xZnxFe2O4) incorporated rubber ferrite composites (RFCs). Ni1−xZnxFe2O4 (where) (bix)varies from 0 to 1 in steps of 0.2 were prepared by usual ceramic techniques. They were then incorporated into a butyl rubber matrix according to a specific recipe. The a.c. electrical conductivity (σa.c) calculations were carried out by using the data available from dielectric measurements and by employing a simple relationship. The a.c. conductivity values were found to be of the order of 10−3 S/m. Analysis of the results shows that σa.c. increases with increase of frequency and the change is same for both ceramic Ni1−xZnxFe2O4 and RFCs. σa.c increases initially with the increase of zinc content and then decreases with increase of zinc. Same behaviour is observed for RFCs too. The dependence of σa.c on the volume fraction of the magnetic filler was also studied and it was found that the a.c. conductivity of RFCs increases with increase of volume fraction of the magnetic filler. Temperature dependence of conductivity was studied for both ceramic and rubber ferrite composites. Conductivity shows a linear dependence with temperature in the case of ceramic samples.

Tin selenide (SnSe) thin films prepared by reactive evaporation

Abstract: Polycrystalline thin films of tin selenide have been prepared by reactive evaporation at substrate temperatures ranging from 473–600 K. Crystallites of the films prepared at substrate temperatures below 525 K are randomly oriented, while they have a strong preferred orientation on the substrate surface at higher substrate temperatures. Optical absorption studies indicate that the fundamental absorption starts at 1.21 eV and it is due to an allowed direct transition.

Thermal diffusivity measurements in organic liquids using transient thermal lens calorimetry

Abstract: Thermal diffusivity measurements are carried out in certain organic liquids using the pulsed dual beam thermal lens technique. The 532 nm pulses from a frequency doubled Q-switched Nd:YAG laser are used as the heating source and an intensity stabilized He-Ne laser serves as the probe beam. Experimental determination of the character- istic time constant of the transient thermal lens signal is verified theoreti- cally. Measured thermal diffusivity values are in excellent agreement with literature values. © 1998 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(98)00510-8)

Functionalized boron nitride porous solids

Abstract: Hexagonal boron nitride (h-BN), also known as white graphene, is well known for its chemical inertness. Recent studies indicate that functionalization of h-BN can tune its physico-chemical properties, including its electrical conductivity. Here we propose a method for the functionalization of h-BN flakes with various oxygen functionalities to make a graphite oxide analogue of h-BN, with a view to develop cross-linked, low-density (∼40 mg cm−3), and porous h-BN solids, as have been recently well cited for graphene and graphite oxide. For the first time, a macro-porous low density h-BN monolith foam is developed via a single step template free chemical route followed by a lyophilisation process. h-BN is known for its high thermal stability, and here oil adsorption by the foam (∼2 g g−1) and complete burning of the adsorbed oil without disrupting the h-BN skeleton were demonstrated indicating the flexibility of tuning the morphology of the h-BN in bulk, like graphite, without losing its inherent physical properties, opening new avenues for h-BN in the energy and environment related fields.