Optimum performance data for the leaching of roasted chalcopyrite concentrate in a jet contactor

Chalcopyrite concentrate has been roasted in a mullite tube furnace and the optimum temperature of roasting determined. The roasted concentrate has been leached with dilute sulphuric acid in a jet contactor. Optimum performance data for leaching, namely temperature, particle size, slurry concentration, acid concentration, nozzle diameter and effective contactor height have been obtained. For predicting the copper concentration in the leached solution, an expression based on a diffusion model has been derived and compared with the experimental data. It has been observed that at low values of mixed phase velocity, the agreement is good, but at high values, the variation is relatively larger.     

Preface of special issue of CCSN2016

Microsystem Technologies -     

Preface

Microsystem Technologies -     

Identification of 3,4-Dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine Derivatives as Novel Selective Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase

Plasmodium falciparum’s resistance to available antimalarial drugs highlights the need for the development of novel drugs. Pyrimidine de novo biosynthesis is a validated drug target for the prevention and treatment of malaria infection. P. falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the oxidation of dihydroorotate to orotate and utilize ubiquinone as an electron acceptor in the fourth step of pyrimidine de novo biosynthesis. PfDHODH is targeted by the inhibitor DSM265, which binds to a hydrophobic pocket located at the N-terminus where ubiquinone binds, which is known to be structurally divergent from the mammalian orthologue. In this study, we screened 40,400 compounds from the Kyoto University chemical library against recombinant PfDHODH. These studies led to the identification of 3,4-dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine and its derivatives as a new class of PfDHODH inhibitor. Moreover, the hit compounds identified in this study are selective for PfDHODH without inhibition of the human enzymes. Finally, this new scaffold of PfDHODH inhibitors showed growth inhibition activity against P. falciparum 3D7 with low toxicity to three human cell lines, providing a new starting point for antimalarial drug development.     

Special issue on computing,communication and sensor network: CCSN,Puri, Odisha,India, 2014

Microsystem Technologies -     

Hidden Markov model a tool for recognition of human contexts using sensors of smart mobile phone

A fast and accurate computational model of HMM (Hidden Markov Model) is proposed for Activity Recognition System using inbuilt sensors of Smart Mobile Phone. Twelve features are calculated from the captured data and the feature vectors are divided into two vectors which are used as inputs to HMM. All computational methods follow probability theories and for measuring differences of two probability based events we used K–L divergence of Kullback and Leibler (Ann Math Stat 22(1):79–86, 1951) known as KLD (Kullback & Leibler Divergence). For comparing of feature values of ground truth and that of experimental values, we have developed an algorithm D-HMM (Divisional-HMM, proposed algorithm). Results show better recognition than existing HF-SVM (Hardware Friendly Support Vector Machine) and also better than our previous work of CFT (Conditional Features using Threshold, a method developed for using different schemes of threshold values for selection and matching purposes of feature values).

     

Unidirectional voltage converter for battery electric vehicle ultrafast charger

Microsystem Technologies - This paper proposes the use of a frequency converter used in the AC motor drives to build a fast charging battery converter for electric vehicles (EV). The possibility of...     

Special issue on International Conference on Microelectronics,Circuits and Systems (Micro 2015), held in Kolkata,India, July, 11–12, 2015

Microsystem Technologies -     

A concurrent model reduction approach on spatial and random domains for the solution of stochastic PDEs

A methodology is introduced for rapid reduced‐order solution of stochastic partial differential equations. On the random domain, a generalized polynomial chaos expansion (GPCE) is used to generate a reduced subspace. GPCE involves expansion of the random variable as a linear combination of basis functions defined using orthogonal polynomials from the Askey series. A proper orthogonal decomposition (POD) approach coupled with the method of snapshots is used to generate a reduced solution space from the space spanned by the finite element basis functions on the spatial domain. POD methods have been extremely popular in fluid mechanics applications and have subsequently been applied to other interesting areas. They have been shown to be capable of representing complicated phenomena with a handful of degrees of freedom. This concurrent model reduction on the random and spatial domains is applied to stochastic partial differential equations (PDEs) in natural convection processes involving randomness in the porosity of the medium and the Rayleigh number. The results indicate that owing to the multiplicative nature of the concurrent model reduction, extremely large computational gains are realized without significant loss of accuracy. Copyright © 2005 John Wiley & Sons, Ltd.