Level of Service for On-street Parking

Debasish Das,Mokaddes Ali Ahmed 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1

Parking of vehicle is one of the most important issues of the urban transportation system in any Central Business District (CBD). A sharp rise in vehicular ownership and insufficient transit system give rise to the huge on-street parking demand leading to a reduction in effective carriageway width, flow speed, creating unnecessary congestion, etc. The problems can be controlled by providing an efficient parking system. The present study aims to estimate the Level of Service (LOS) of on-street parking. LOS is calculated based on three parking selection criteria, viz. Parking Characteristic (PC), Safety Characteristic (SC) and Design Characteristic (DC). Four CBDs of Kolkata Metropolitan Area (KMA) are selected as a case study area. The overall LOS equation is formulated by Analytic Hierarchy Process (AHP). Cluster analysis and Zero dimension process are used to standardize the variables to designated LOS. Various surveys are carried out for data collection. The data are analyzed using SPSS. Finally, the overall LOS for on-street parking is estimated for all the selected CBDs.

GLOBAL FINANCIAL CRISIS AND FOREIGN DEVELOPMENT ASSISTANCE SHOCKS IN LEAST DEVELOPING COUNTRIES

DEBASISH KUMAR DAS,CHAMPA BATI DUTTA 중앙대학교 경제연구소 2013 Journal of Economic Development Vol.38 No.2

This paper evaluates whether the exogenous component of the global financial crisis affects OECD-DAC EU donor countries ODA disbursements to the LDCs and how it impacts on LDCs economic prosperity. Using both static and dynamic panel techniques, we find that global financial crisis in OECD-EU donor countries are causes for the significant downside of ODA flows to the LDCs. Consequently it adversely affects through the various transmission channels (e.g., ODA disbursements, remittances, bilateral financial flows, export growth) to the LDCs economic growth. Our results also explore that due to countercyclical role of ODA flows from the donors’ largely affect to the LDCs economic development process negatively. The robustness checks using alternative estimation technique supports our original estimation results in every context.

Enhanced lipid content in Chlorella sp. FC2 IITG via high energy irradiation mutagenesis

Debasish Das,Baskar Selvaraj,Basavaraj Palabhanvi,Vikram Kumar,Muthusivaramapandian Muthuraj 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.1

High energy ultra-violet radiation was used to induce mutations in the wild type strain Chlorella sp. FC2 IITG and the mutants obtained were screened for enhanced lipid content targeted towards biodiesel production. Screening of mutants under nitrogen starved photoautotrophic condition showed five mutant strains with higher lipid content as compared to the wild type strain. Maximum neutral lipid content of 22.26% (w/w, DCW) was found for FC2-25UV mutant strain, which was 48.4% higher than that of wild type culture. Further characterization under photoautotrophic two stage high cell density cultivation of lipid rich FC2-25UV resulted in total lipid content of 68% (w/w, DCW), which was 21.43% higher than the wild type strain with a marginal improvement of 11% in the total lipid productivity. Comparison of enzyme activity assays under nitrogen starved conditions in both the strains revealed an 18.2% and 31.25% increase in acetyl CoA carboxylase and di-acyl-glycerol transferase activity of mutant. The FAME composition analysis showed 41.5% and 24% increase in the fractions of C18:2 and C18:1 in the mutant strain when compared to the wild type strain with no significant difference in the other FAME fractions. Thus, the mutant strain could be a potential candidate for biodiesel production.

Performance of heated pin fin arrangement in a rectangular cavity-An experimental approach

Debasish Das,Ankur Dwivedi,Satya Prakash Verma 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.4

For the last few decades there has been very remarkable growth in electronics and computing technologies and it is still continuing unceasingly. The performance of various engineering devices is limited by thermal management problems. The present investigation deals with heat transfer augmentation through pin fins in gamma of an air-filled rectangular cavity as function of corresponding pertinent factors- fin height, fin spacing as well as Rayleigh number and suggests a direction of future advancements. The experiments are carried out for wide domains of numerous persuading parameters- fin height (12.5 mm ≤ L ≤ 37.5 mm), fin spacing (25 mm ≤ S ≤ 100 mm) and Rayleigh number (360000 ≤ Ra ≤ 680000). Fin spacing is determined as most critical parameter affecting system performance.

Fabrication of hierarchical Bentonite/Chitosan/NiFe₂O₄ ternary nanocomposite and its efficiency in the removal of Pb(II) from aqueous medium

Debasish Guha Thakurata,Arijita Paul,Krishna Chandra Das,Siddhartha Sankar Dhar 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.4

Lead is the most globally bountiful harmful substantial component in nature. Its utilization can be followed to verifiable occasions. The current work archives the combination, portrayal, and utilization of bentonite/chitosan/NiFe₂O₄ ternary novel nanocomposite. Nanostructured nickel ferrite was joined with chitosan and bentonite to frame a novel ternary nanocomposite. The nanocomposite was portrayed by FT-IR, powder XRD, VSM, and TEM investigation. All the logical outcomes affirm the fruitful arrangement of ternary composite. The as-blended nanomaterial was applied as nanoadsorbent for the evacuation of lead (II) from water. The ideal composite portion was 50 ㎎/100 mL was seen as profoundly powerful for the evacuation of 82% Pb (II) particles from 200 ppm watery arrangement. This ferromagnetic, minimal effort, the eco-accommodating nanocomposite may end up being helpful for the expulsion of lead from watery arrangement at the mechanical level.

Reactive Behavior of Ferrihydrite and Aluminic Ferrihydrite Toward the Adsorption of Arsenate

Debasish Mohapatra,박경호,Debaraj Mishra,G. Roy Chaudhury,R. P. Das 한국자원공학회 2006 Geosystem engineering Vol.9 No.2

The adsorption of arsenate (As(V)) on “ferrihy- drite” prepared by two different methods; “aluminic ferrihydrite” (Fe(III)/Al(III) molar ratio 1:1) and the stability of As(V) bearing materials were investigated. The parameters optimized for adsorption were pH, contact time, adsorbent and As(V) concentration. For leaching study four different leaching reagents (10 mg C/L dissolved organic matter, 0.1M phosphate, 0.1M citrate and 0.1M oxalate) were used. The kinetics of arsenic adsorption on both type of ferrihydrites were similar with an equilibrium time of 1h; whereas, in case of aluminic ferrihydrite the equilibrium time was 3h. For aluminic ferrihydrite, maximum adsorption was found at pH 6.0. Whereas, for ferrihydrites pH 7.0 was found to be the best for As(V) adsorption. The highest As(V) adsorption capacity was shown by aluminic ferrihydrite (21.8 mg/g), followed by ferrihydrite prepared by emulsion method and ferrihydrite prepared by ordinary method (14.9 and 9.8 mg/g, respectively). In case of As(V) extraction from the loaded materials, the pH had a significant effect. In all cases, except citrate for aluminic ferrihydrite, extraction decreased with increasing pH in the range 5.0- 8.0. For oxalate the iron extraction and for citrate the aluminium extraction followed the same trend as that for arsenic as a function of pH, suggesting that dissolution of these metals and consequent release of the adsorbed arsenic is one of the main mechanisms for arsenic extraction. However, for phosphate and DOM, the As(V) extraction mechanism was competition between arsenic and those anions for adsorption sites.

Removal of Arsenic(V) from Aqueous Solutions by Using Natural Minerals

Mohapatra Debasish,Mishra Debaraj,Chaudhury G. Roy,Das R.P.,Park, Kyung-Ho The Korean Institute of Resources Recycling 2006 資源 리싸이클링 Vol.15 No.5

The removal of arsenic(V) using four different natural minerals were evaluated. Parameters like contact time, pH, adsorbent dosages, and As(V) concentration were optimized. The kinetics of adsorption was observed to be fast and reached equilibrium within 2h. As(V) adsorption on studied minerals was dependent on pH and followed a pseudo-second-order reaction model. For kaolin, maximum adsorption was found at pH 5.0. Whereas, in case of other three minerals, a pH range of 6.0-7.0 was found to be the best for As(V) adsorption. The maximum adsorption capacity (Q) was calculated by fitting Langmuir equation to the adsorption isotherms obtained under a specified condition. From the slope of best fit, the Q values were calculated to be 2.07, 2.15, 1.95 and 0.86 mg As(V)/g of bauxite, wad, iron ore and kaolin, respectively. Desorption of As(V) from loaded materials was dependent on the type of leaching reagents used. Based on the results, it was found that among the studied natural minerals, wad was the best As(V) adsorbent.

Reactive Behavior of Ferrihydrite and Aluminic Ferrihydrite Toward the Adsorption of Arsenate

Mohapatra, Debasish,Mishra, Debaraj,Chaudhury, G. Roy,Das, R.P.,Park, Kyung-Ho 한국암반공학회 2006 Geosystem engineering Vol.9 No.2

The adsorption of arsenate (As(V)) on "ferrihydrite" prepared by two different methods; "aluminic ferrihydrite" (Fe(III)/ AI(III) molar ratio 1:1) and the stability of As(V) bearing materials were investigated. The parameters optimized for adsorption were pH, contact time, adsorbent and As(V) concentration. For leaching study four different leaching reagents (10mg C/L dissolved organic matter, 0.1M phosphate, 0.1M citrate and 0.1M oxalate) were used. The kinetics of arsenic adsorption on both type of ferrihydrites were similar with an equilibrium time of 1h; whereas, in case of aluminic ferrihydrite the equilibrium time was 3h. For aluminic ferrihydrite, maximum adsorption was found at pH 6.0. Whereas, for ferrihydrites pH 7.0 was found to be the best for As(V) adsorption. The highest As(V) adsorption capacity was shown by aluminic ferrihydrite (21.8 mg/g), followed by ferrihydrite prepared by emulsion method and ferrihydrite prepared by ordinary method (14.9 and 9.8 mg/g, respectively). In case of As(V) extraction from the loaded materials, the pH had a significant effect. In all cases, except citrate for aluminic ferrihydrite, extraction decreased with increasing pH in the range 5.0-8.0. For oxalate the iron extraction and for citrate the aluminium extraction followed the same trend as that for arsenic as a function of pH, suggesting that dissolution of these metals and consequent release of the adsorbed arsenic is one of the main mechanisms for arsenic extraction. However, for phosphate and DOM, the As(V) extraction mechanism was competition between arsenic and those anions for adsorption sites.

C60 embedded diamond-like nanocomposite thin film

Jana Sukhendu,Das Sayan,De Debasish,Shakti Nanda,Mondal Anup,Bhattacharya Sekhar,Gongopadhyay Utpal 한국탄소학회 2022 Carbon Letters Vol.32 No.1

Diamond-like nanocomposite (DLN) has become a promising thin film for many fields of applications due to its unique and tunable properties. However, low optical bandgap and thermal stability limits its application in many fields particularly as antireflection coating on solar cell. In the present study, the DLN thin film has been deposited using a mixed liquid precursor by rf-PECVD process. Surprisingly the presence of nc-C60 in FCC structure in DLN matrix has been observed. The degree of crystallinity and diameter of C60 have been increased significantly after annealed at 850 °C. The film has been annealed at 850 °C to primarily investigate its feasibility as antireflection coating (ARC) in compatible with industrial solar cell fabrication process. The refractive index and optical bandgap of the film were around 1.80 and 4.10 eV, respectively. Moreover, the optical bandgap has decreased to some extent to 3.92 eV even after annealing at such high temperature. The high SiOx at% and embedded nc-C60 enhanced the optical transparency and thermal stability of the DLN film. The solar-weighted average reflection of DLN-coated textured silicon was reduced significantly to 1.91%. The C60 embedded DLN film has a great potential to apply in different optoelectronic devices especially in solar cell as ARC.

Arsenic adsorption mechanism on clay minerals and its dependence on temperature

Debaraj Mishra,Debasish Mohapatra,Gautam Roy Chaudhury,Radhanath Prasad Das 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.3