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.

Visual question answering: a state-of-the-art review

Abstract: Visual question answering (VQA) is a task that has received immense consideration from two major research communities: computer vision and natural language processing. Recently it has been widely accepted as an AI-complete task which can be used as an alternative to visual turing test. In its most common form, it is a multi-modal challenging task where a computer is required to provide the correct answer for a natural language question asked about an input image. It attracts many deep learning researchers after their remarkable achievements in text, voice and vision technologies. This review extensively and critically examines the current status of VQA research in terms of step by step solution methodologies, datasets and evaluation metrics. Finally, this paper also discusses future research directions for all the above-mentioned aspects of VQA separately.

Thermophysical, mechanical and dielectric studies on piperidinium p -hydroxybenzoate

Abstract: Single crystals of recently identified nonlinear optical material, piperidinium p-hydroxybenzoate (PDPHB), were grown by solution cooling method It crystallizes in a monoclinic system with a noncentrosymmetric space group Cc Thermal stability and decomposition behavior of PDPHB are illustrated through thermogravimetric, differential thermal and differential calorimetric analysis The thermal diffusivity, thermal conductivity, and specific heat capacity of the grown crystals, which are the three most important thermo-physical parameters in heat transfer calculations, are calculated by an improved photopyroelectric technique The room temperature hardness test has been performed on crystallographic planes (200), (020), and (002) using Vickers microhardness tester and the results are analyzed through the classical Meyer’s law The dielectric constant, dielectric loss, and ac conductivity are studied as a function of frequency (100 Hz to 1 MHz) and temperature (313–363 K) All these studies are performed for the first time and aimed to explore the useful and safe region of thermal, mechanical, and electrical properties to enhance effectiveness of PDPHB crystals for device fabrications

Isora Fibres and their Composites with Natural Rubber

Abstract: This paper reports the use of a natural fibre ‘isora’ as reinforcement for natural rubber. Isora is a bast fibre separated from the bark of the Helicteres isora plant by retting. The effect of diff...

Colossal thermoelectric power in Gd-Sr manganites

Abstract: Manganites belonging to the series Gd1−xSrxMnO3 (x=0.3, 0.4 and 0.5) were prepared by wet solid-state reaction and their thermoelectric power was evaluated. Thermoelectric power measurements revealed a peak value at ~40 K. All the samples exhibited a colossal thermopower at ~40 K and in that Gd0.5Sr0.5MnO3 exhibited a maximum value of ~35 mV/K, which is the largest reported for these class of materials at this temperature. Temperature-dependent magnetisation measurements showed that the samples exhibit a phase transition from paramagnetic to spin-glass–like state at these temperatures. Plausible mechanisms responsible for the observed colossal thermoelectric power in Gd-Sr manganites are discussed.

Thermocatalytic cleavage of C-C and C-O bonds in model compounds and kraft lignin by NiMoS2/C nanocatalysts

Abstract: The effective utilization of biomass derived lignin as a source of chemicals and fuels involves chemical transformation such as depolymerization and deoxygenation reactions. Since lignin macromolecules are predominantly made up of both C-C and C-O bond linkages, the simultaneous cleavage of these linkages requires the design of a highly efficient catalytic system. Therefore, this paper reports an innovative technique for preparing NiMoS2 nanoparticles as an upgrading catalyst for lignin via a hydrodeoxygenation (HDO) route. The key aspect of this strategy is to produce single layered, short MoS2 slabs (∼4 nm) that possess increasingly exposed edge active sites in contrast to the bulk MoS2 materials. A microemulsion synthesis technique was utilized to prepare the NiMoS2 nanocatalyst, which was dispersed on an activated carbon support giving a weak metal-support interaction that facilitated a "metal-like character" of the catalyst as well as the formation of type-II NiMo phases. Initial catalyst screening for the HDO of lignin phenolic model compounds (phenol, guaiacol, veratrole and syringol) showed that partial deoxygenation accompanied by hydrogenation was the favoured reaction pathway. Moreover, rapid cleavage of C-C and C-O bonds of recalcitrant α-O-4, β-O-4 and 4-O-5 linkages was achieved in a relatively short reaction time (i.e. <3 h). Eventually, the catalyst was demonstrated to be capable of depolymerizing kraft lignin by hydrogenolysis to produce monomeric and dimeric phenolic compounds as indicated by the GPC and GC-MS results. The reusability of the catalyst for guaiacol conversion, as a prototype for other phenolic compounds, showed that catalytic activity is stable and maintained even after three reaction cycles. Catalytic stability was ascribed primarily to the preservation of the catalytic active edges containing short MoS2 layers and high stacking (up to 7 layers) and as a result, leached sulphur and coke formed were minimized. Thus, synthesising amorphous NiMoS2/C nanocatalysts by the microemulsion technique represents a promising alternative for designing cheap and efficient catalysts for lignin upgrading.