Low-Power Multimedia DSP Systems

Parhi,Keshab K. 대한전자공학회 1997 ICVC : International Conference on VLSI and CAD Vol.5 No.1

In a few years, multimedia will become part of everyone's life. This paler presents an overview of DSP processors which are targeted for multimedia applications. Current and future trends of these processors are predicted. Reduction of power consumption, ic these systems is one of the major challenges for implementation. Various techniques for reduction of power consumption are reviewed.

A kinetic study on hydrochloric acid leaching of nickel from Ni-Al₂O₃ spent catalyst

Parhi, P.K.,Park, K.H.,Senanayake, G. Korean Society of Industrial and Engineering Chemi 2013 Journal of industrial and engineering chemistry Vol.19 No.2

Hydrochloric acid leaching of nickel from spent Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalyst (12.7% Ni, 39.2% Al and 0.68% Fe) has been investigated at a range of conditions by varying particle size (50-180μm), acid concentration (0.025-2M), pulp density (0.2-0.4%, w/v) and temperature (293-353K). Nickel was selectively leached from the catalyst, irrespective of the different conditions. Under the most suitable conditions (1M HCl, 323K, stirring at 500rpm, 50-71μm particle size), the extent of leaching of Ni and Al after 2h was 99.9% and 1%, respectively. The XRD pattern of the spent catalyst corresponded to crystalline α-Al<SUB>2</SUB>O<SUB>3</SUB> along with elemental Ni. The peak due to elemental Ni was absent in the residue sample produced at the optimum leaching conditions, confirming the complete dissolution of Ni from the spent catalyst. The leaching results were well fitted with the shrinking core model with apparent activation energy of 17kJ/mol in the temperature range of 293-353K indicating a diffusion controlled reaction.

Liquid-liquid extraction and separation of total rare earth (RE) metals from polymetallic manganese nodule leaching solution

Parhi, P.K.,Park, K.H.,Nam, C.W.,Park, J.T. Elsevier 2015 Journal of rare earths Vol.33 No.2

Formulation optimization of PVA/HPMC cryogel of Diltiazem HCl using 3-level factorial design and evaluation for ex vivo permeation

Rabinarayan Parhi,Podilam Suresh,Suhasini Patnaik 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.3

The aim of the present research was to optimize cryogel formulation of Diltiazem hydrochloride (DZ) with poly(vinyl alcohol) (PVA) and hydroxypropyl methylcellulose (HPMC) by utilizing response surface methodology followed by ex vivo permeation study on the optimized gel containing penetration enhancers. A 3-level factorial design was employed to formulate the experimental runs and to evaluate the effect of two independent variables such as the concentration of PVA and HPMC on characteristics of cryogel such as bioadhesive strength (BS) and in vitro drug release (dependent variables). Response surface plots such as contour and 3D plots were generated by the Design Expert software to analyze the effect of independent variables on dependent variables. Fourier transform infrared spectroscopy studies confirmed the absence of interaction between DZ and polymers. Among various models generated by the software, quadratic model was found to be best fit for both the responses. Both the formulation factors influenced BS synergistically. However, the effect of HPMC concentration was more pronounced compared to concentration of PVA. But, an opposite effect shown by both the formulation factors on cumulative percentage of drug release (CPR) in 8 h. The optimized batch of cryogel of DZ selected by the software was having composition of 5 %of PVA and 2 %of HPMC. Penetration enhancers such as 1,8-cineole, d-limonene and carvone were incorporated into the optimized gel and permeation study was carried out using abdominal skin of rat. The study demonstrated a highest flux of 118 ± 5.81 μg/cm²/h in case of 1,8-cineole containing gel followed by carvone and d-limonene.

A kinetic study on hydrochloric acid leaching of nickel from Ni–Al2O3 spent catalyst

P.K. Parhi,K.H. Park,G. Senanayake 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Hydrochloric acid leaching of nickel from spent Ni–Al2O3 catalyst (12.7% Ni, 39.2% Al and 0.68% Fe) has been investigated at a range of conditions by varying particle size (50–180 mm), acid concentration (0.025–2 M), pulp density (0.2–0.4%, w/v) and temperature (293–353 K). Nickel was selectively leached from the catalyst, irrespective of the different conditions. Under the most suitable conditions (1 M HCl,323 K, stirring at 500 rpm, 50–71 mm particle size), the extent of leaching of Ni and Al after 2 h was 99.9%and 1%, respectively. The XRD pattern of the spent catalyst corresponded to crystalline a-Al2O3 along with elemental Ni. The peak due to elemental Ni was absent in the residue sample produced at the optimum leaching conditions, confirming the complete dissolution of Ni from the spent catalyst. The leaching results were well fitted with the shrinking core model with apparent activation energy of 17 kJ/mol in the temperature range of 293–353 K indicating a diffusion controlled reaction.

Effect of External Electric Field on Morphology of Copper Phthalocyanine-Fullerene Blended Films during Annealing

Anukul Prasad Parhi,S. Sundar Kumar Iyer 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

The thin-film morphology and segregated phases of constituents in blends oforganic semiconductors play an important role in determining the performanceof devices fabricated with these constituents. In this study, we explored the effectof an external electric field applied during annealing on the morphology andphase of blended films of two popular organic semiconductors, copperpthalocyanine (CuPc) and buckminsterfullerene (C60). Films of different blendratios annealed at various temperatures in both the presence and absence of anelectric field were characterized using scanning electron microscopy (SEM), Xraydiffraction (XRD), and ultraviolet-visible (UV-vis) spectroscopy. Thecharacteristics of annealed pristine CuPc films were also included forcomparison. The observed changes in the properties of the blended filmsfollowing the annealing, including the abrupt phase segregation of the blendedconstituents in the films, are discussed. The polarizability of the molecules wascalculated using density functional theory (DFT) to explain the interaction,stacking, and segregation of the molecules in the blend. The results showed thatapplication of an electric field during annealing of the blended films is anadditional control parameter that can help tune the properties of the blended film.

Selective dissolution of copper from copper-chromium spent catalyst by baking–leaching process

P.K.Parhi,T.R. Sethy,P.C. Rout,K. Sarangi 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

The selective leaching of copper from the spent Cu-Cr catalyst was carried out with H2SO4. The effect ofdifferent parameters such as acid concentration, pulp density, temperature and particle size on leachingwas investigated. The maximum extraction of copper and chromium was 67.25 and 2.3%, respectively atparticle size 45–53 mm, pulp density 2.5%, temperature 90 8C, time 180 min. Therefore, baking followedby leaching approach was adopted for dissolution of spent copper-chromium catalyst using H2SO4 toenhance the metal leaching efficiency. At the optimum baking–leaching condition i.e. baking time 2 h,baking temperature 300 8C, baking acid concentration 0.5 M, leaching temperature 35 8C, time 60 min,[H2SO4] 4%, P.D. 2.5%, the extraction of copper and chromium was 99.9% and 1.2%, respectively, ensuringthe selective dissolution of copper. The XRD and Fe-SEM-Edax characterization analysis of typicalsamples (original, baked mass and typical residue) were compared and reported. The XRD and Fe-SEMEdaxanalysis of the baked mass indicated the complete sulfation of copper and chromium by H2SO4yielding CuSO4 (H2O) and (Cr)2(SO4)3, respectively in solid phase. The absence of XRD peakscorresponding to CuSO4 H2O in the final typical leach residue (obtained at optimum baking–leachingcondition) confirmed the complete dissolution of copper from Cu-Cr catalyst.

Studies on Removal of Low Content Copper from the Sea Nodule Aqueous Solution using the Cationic Resin TP 207

Park, K.H.,Parhi, P.K.,Kang, N.-H. Taylor Francis 2012 Separation science and technology Vol.47 No.10

Probabilistic Spherical Detection and VLSI Implementation for Multiple-Antenna Systems

Park, C.S.,Parhi, K.K.,Sin-Chong Park IEEE 2009 IEEE transactions on circuits and systems. a publi Vol.56 No.3

<P>This paper presents a novel probabilistic spherical-detection (P-SD) method which applies the probabilistic-search algorithm to conventional depth-first SD (DF-SD). By confining the tree search into candidates which can be selected in an adaptive manner, a large number of promising candidates can be evaluated before termination. Consequently, the proposed P-SD improves the error performance of DF-SD with early termination, while retaining the hardware efficiency. An efficient VLSI architecture is proposed for implementation of the P-SD algorithm, and the results of the synthesized architecture are presented. The main advantage of P-SD is that it can fully exploit the state-of-the-art architectures of DF-SD, since it can be implemented by simply adding two functional blocks to conventional DF-SD. By analyzing the performance-complexity tradeoffs, it is concluded that our proposed P-SD is advantageous over conventional DF-SD and <I>K</I>-best algorithm, when the maximum-likelihood error performance is desired.</P>

ON SEMILOCAL CONVERGENCE OF A MULTIPOINT THIRD ORDER METHOD WITH R-ORDER (2 + p) UNDER A MILD DIFFERENTIABILITY CONDITION

P. Parida,D.K. Gupta,S.K. Parhi 한국전산응용수학회 2013 Journal of applied mathematics & informatics Vol.31 No.3

The semilocal convergence of a third order iterative methodused for solving nonlinear operator equations in Banach spaces is establishedby using recurrence relations under the assumption that the secondFr´echet derivative of the involved operator satisfies the !-continuity conditiongiven by ∥F′′(x) − F′′(y)∥ ≤ ω(∥x − y∥), x, y ∈ Ω, where, ω(x) is anondecreasing continuous real function for x > 0, such that ω(0) ≥ 0. Thiscondition is milder than the usual Lipschitz/H¨older continuity conditionon F′′. A family of recurrence relations based on two constants dependingon the involved operator is derived. An existence-uniqueness theorem isestablished to show that the R-order convergence of the method is (2+p),where p ∈ (0, 1]. A priori error bounds for the method are also derived. Two numerical examples are worked out to demonstrate the efficacy of ourapproach and comparisons are elucidated with a known result.