Higher College of Technology

About: Higher College of Technology is a based out in . It is known for research contribution in the topics: Higher education & Tourism. The organization has 369 authors who have published 379 publications receiving 729 citations.

Nonlinearity managed passively harmonic mode-locked Er-doped fiber laser based on carbon nanotube film.

Abstract: We examine the implication of intracavity nonlinearity for harmonic mode locking (HML) by exploiting highly nonlinear fiber in a carbon nanotube film mode-locked Er-doped fiber laser. It is found that the reasonably large nonlinearity is of benefit to increase the extent of harmonic order while the excessive nonlinearity leads to some peculiar multi-pulse patterns such as noise-like pulse and soliton rain. Via appropriate nonlinearity management, nearly 4 GHz repetition rate pulses at the 91st harmonic with 936 fs pulse duration are delivered under the pump power of 280 mW. The pulse stability is evidenced by the super-mode suppression ratio of 35.6 dB. To the best of our knowledge, it is the highest repetition rate yet reported for a passively HML fiber laser based on a film-type physical saturable absorber. Furthermore, the laser exhibits steep pumping efficiency slope of ${\gt}{19}\;{\rm MHz/mW}$, which is also a record among all of the passively HML fiber lasers.

Modelling and optimisation of hardness in citrate stabilised electroless nickel boron (ENi-B) coatings using back propagation neural network – Box Behnken design and simulated annealing – genetic algorithm

Abstract: In this work, a novel citrate stabilised electroless bath was developed and the process parameters (concentrations of nickel, reducing agent, and stabiliser) were optimised to achieve the maximum h...

SMEDDS for improved oral bioavailability and anti-hyperuricemic activity of licochalcone A.

Abstract: The aim of this study was to develop licochalcone A-loaded self-microemulsifying drug delivery system (LCA-SMEDDS) to improve bioavailability and anti-hyperuricemic activity of hydrophobic natural ...

Spent tea waste as a biomass for co-gasification enhances the performance of semi-industrial gasifier working on groundnut shell

Abstract: An effective utilization of agricultural waste as an energy source for decentralised power generation and thermal applications can meet the increasing energy demand in rural areas. A substantial number of thermo-chemical conversion systems are used for this purpose; nevertheless, it is significant to improve their efficiency to widen the implementation of this technology for various applications. Groundnut shell is one of the popular agricultural wastes available in many countries like India. Due to its low bulk density and physical nature co-gasification of this feedstock with another biomass is not popular. However, a high carbonaceous powdery biomass like Spent Tea Waste (STW), a waste after brew tea can be suitably mixed with groundnut shell along with some moisture to accomplish this task. To prove this strategy an experimental study has been conducted at various combinations of these two types of biomass as feedstock in a 115 kWth semi-industrial type gasifier, and its performance parameters are studied for possible operating conditions of the gasifier. The observations show that the wet STW can maintain a uniform consistency, when mixing both the biomasses until its composition is 40% of the blend. The results show that the increase in hydrogen composition, calorific value and cold gas efficiency is in the ranges of 9.9–21.5%, 4.1–10.4% and 3.9–9.9% respectively as compared to groundnut shell. Besides, the maximum calorific value of producer gas is 6.68 MJ m−3.

Probabilistic Dynamics of Two-Layer Geophysical Flows

Abstract: The two-layer quasigeostrophic flow model is an intermediate system between the single-layer two-dimensional barotropic flow model and the continuously stratified three-dimensional baroclinic flow model. This model is widely used to investigate basic mechanisms in geophysical flows, such as baroclinic effects, the Gulf stream and subtropical gyres. We consider the two-layer quasigeostrophic flow model under stochastic wind forcing on the top layer. The fluctuating part of the wind forcing is modeled as the generalized time derivative of a Wiener process. We first transform this stochastic two-layer fluid system into a coupled system of random partial differential equations. Then we prove that the stochastic two-layer fluid system has finite sets of asymptotically determining functionals (such as determining modes and determining nodes) in probability. Furthermore, we show that the asymptotic probabilistic dynamics of this system depends only on the top fluid layer. Namely, in the probability sense and asymptotically, the dynamics of the two-layer quasigeostrophic fluid system is determined by the top layer. In other words, the bottom layer is slaved by the top layer. This conclusion is true provided that the Wiener process and the fluid parameters satisfy a certain condition. In particular, this latter condition is satisfied when the trace of the covariance operator of the Wiener process is small enough and the Ekman constant r is sufficiently large.