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Prasun Mahanti,Mark Southwick Robinson,David Carl Humm,Robert Vernon Wagner,Nicholas Michael Estes,Jean-Pierre Williams 한국우주과학회 2023 Journal of Astronomy and Space Sciences Vol.40 No.4
Lunar permanently shadowed regions (PSRs) never see direct sunlight and are illuminated only by secondary illumination - light reflected from nearby topography. The ShadowCam imaging experiment onboard the Korea Pathfinder Lunar Orbiter is acquiring images of these PSRs. We characterize and discuss the nature of secondary illumination for the Shackleton PSR from ShadowCam radiance-calibrated images. We also use modeling to understand the magnitude and direction of the secondary illumination. Results from our analysis highlight the non-homogeneous, dynamic, and complex nature of PSR secondary lighting. Knowledge of the direction of the secondary illumination is crucial for reli-able interpretation of contrasts observed in ShadowCam images. This preliminary analysis of the floor of Shackleton crater from images acquired over multiple secondary illumination conditions does not reveal indications of exposed surface ice, even though temperatures are constantly below 110K.
Multi-Item Inventory Problems Revisited Using Genetic Algorithm
Prasun Das 한국경영과학회 2007 Management Science and Financial Engineering Vol.13 No.2
This paper makes an attempt to compare the two important methods for finding solutions of multiitem inventory problem with more than one conflicting objectives. Panda et al. [9] discusses a distance-based method to find the best possible compromise solution with variation of priority under the given weight structure. In this paper, the problem in [9] is revisited through the Pareto-optimal front of genetic algorithm with the help of a situation of retail stocking of FMCG business. The advantages of using the solutions from the perspective of the decision maker obtained through multiobjective optimization are highlighted in terms of population search, weighted goals and priority structure, cost, set of compromise solutions along with prevention of stock-out situation.
Prasun Das 한국경영과학회 2005 Management Science and Financial Engineering Vol.11 No.2
This paper considers a special case of the two-dimensional bin-packing problem for identical items. The objective of this work is to maximize the space utilization. The main contribution of the paper is to suggest a new heuristic algorithm keeping in view the existing complexity of racking system for the footwear boxes in the compartments of different sizes for a warehouse. The results show that a significant improvement can be obtained. An economic choice of compartments is also estimated using the criteria for maximizing space utilization. A non-linear mathematical model was presented based on the constraints of racking dynamics.
Valorization of polyhydroxyalkanoates production process by co-synthesis of value-added products
Kumar, Prasun,Kim, Beom Soo Elsevier 2018 Bioresource technology Vol.269 No.-
<P><B>Abstract</B></P> <P>Polyhydroxyalkanoates (PHAs) are the only polyesters that are completely synthesized biologically and possess features equivalent to petroleum-based plastics besides being biodegradable. PHA based materials may certainly prove helpful in addressing the concerns caused due to the indiscriminate use of synthetic plastics. However, the cost of producing these polymers on a large scale is still uneconomical. Various approaches have been developed to tackle this issue through usage of agro-industrial wastes, co-production of high market value products, polymer extraction using green solvents, etc. The advent of recombineering and CRISPR technologies has broadened the scope of constructing a microbe capable of synthesizing multiple products with economic feasibility. Quite a few high-market value chemicals are possible to synthesize along with the favorable accumulation of PHA. The present article attempts to review all PHA polymer co-production processes with other chemicals reported till date and discusses the opportunities for their large-scale operation in future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Technical obstacles and solutions in economic production of PHA are discussed. </LI> <LI> Current scenario of various integrative approaches has been presented. </LI> <LI> Biorefinery has a central role in the overall improvement of circular bioeconomy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jana, Prasun,Bhaskar, K. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.2
Rigorous analytical solutions are obtained for the plane stress problem of a rectangular plate subjected to non-linearly distributed bending loads on two opposite edges. They are then used in a Galerkin type solution to obtain the corresponding convergent buckling loads. It is shown that the critical bending moment depends significantly on the actual edge load distribution and further the number of nodal lines of the buckled configuration can also be different from that corresponding to a linear antisymmetric distribution of the bending stresses. Results are tabulated for future use while judging approximate numerical solutions.
Kumar, Prasun,Jun, Hang-Bae,Kim, Beom Soo ELSEVIER 2018 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.107 No.2
<P><B>Abstract</B></P> <P>Polyhydroxyalkanoates (PHA) have emerged as a potential alternative to synthetic plastics, although its large-scale production is limited by the expenditure incurred in feed materials. Co-production of various valuable bioproducts along with PHA has been proposed to alleviate the overall production cost. Here, high-yield co-production of PHA and carotenoids was achieved in single step fermentation by <I>Paracoccus</I> sp. LL1. The halophilic bacterial strain could metabolize a wide range of substrates including methanol, lactose, galactose, glycerol, fructose, mannitol, etc. Under batch fermentation using mineral media supplemented with 2% glycerol, <I>Paracoccus</I> sp. LL1 synthesized 3.77gL<SUP>−1</SUP> PHA with concomitant production of 3.6mgL<SUP>−1</SUP> of carotenoids after 96h. An enhancement of 2.2-folds in total dry cell weight (DCW) was achieved through cell retention culture of <I>Paracoccus</I> sp. LL1, resulting in a maximum DCW (24.2gL<SUP>−1</SUP>) containing PHA (39.3%, ww<SUP>−1</SUP>) with concomitant enhancement in the production of total carotenoids. <I>Paracoccus</I> sp. LL1 could convert glycerol into carotenoids and PHA to a level of 7.14mgL<SUP>−1</SUP> and 9.52gL<SUP>−1</SUP>, respectively. It is the first report showing value addition in PHA production process through co-production of high value carotenoids by <I>Paracoccus</I> sp. using glycerol as substrate.</P>
Kumar, Prasun,Singh, Mamtesh,Mehariya, Sanjeet,Patel, Sanjay K S,Lee, Jung-Kul,Kalia, Vipin C Association of Microbiologists of India 2014 Indian journal of microbiology Vol.54 No.2
<P>Ecobiotechnological approach is an attractive and economical strategy to enrich beneficial microbes on waste biomass for production of Polyhydroxyalkanoate (PHA). Here, six strains of Bacillus spp. were used to produce co-polymers of PHA from pea-shells. Of the 57 mixed bacterial cultures (BCs) screened, two of the BCs, designated as 5BC1 and 5BC2, each containing 5 strains could produce PHA co-polymer at the rate of 505-560?mg/l from feed consisting of pea-shell slurry (PSS, 2?% total solids) and 1?% glucose (w/v). Co-polymer production was enhanced from 65-560?mg/l on untreated PSS to 1,610-1,645?mg/l from PSS treated with defined hydrolytic bacteria and 1?% glucose. Supplementation of the PSS hydrolysate with sodium propionate enabled 5BC1 to produce co-polymer P(3HB-co-3HV) with a 3HV content up to 13?% and a concomitant 1.46-fold enhancement in PHA yield. Using the principles of ecobiotechnology, this is the first demonstration of PHA co-polymer production by defined co-cultures of Bacillus from biowaste as feed under non-axenic conditions.</P>
Chiranjit Bhowmik,Prasun Chakraborti 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.3
Experimental modal analysis of electrical transmission tower has been a challenging task for transmission tower researchers and design engineers in industry all over the world. Requirement of large numbers of sensors and accelerometers have been major constrain. In this study an innovative approach has been developed to investigate the dynamic characteristics and behavior of tower structure through analytical and experimental modal analysis. Firstly, a scale down (1:15) prototype model of transmission tower structure has been constructed with mild steel straps, joint together by welding, for modal testing. Modal hammer test has been conducted on the prototype tower model for extracting modal parameters; modal frequency, modal damping and modes, of the tower model which representing the actual tower structure. Secondly, the transmission tower structure has been modeled in standard finite element tools and analyzed analytically for natural frequencies. The first six natural frequencies and corresponding mode shapes have been determined analytically and first six natural frequencies have also been determined experimentally and compared with each other. The first six natural frequencies are determined analytically, the frequency range of 2–9 Hz has been found. The analytical and experimental modal analysis of transmission tower structure has been found to be in correlation with some differences. The maximum natural frequencies percentage difference 11.1% has been found; between the scale down model and the stand software model. Additionally, the tower structure has been modified and optimized to improve the stiffness of the diaphragm as per specification and practical limitations. The first order natural frequency of the modified tower has been reduced to 2.171 Hz from the 2.1773 Hz.