Soil-structure interaction analysis of beams resting on multilayered geosynthetic-reinforced soil

Deb, Kousik Techno-Press 2012 Interaction and multiscale mechanics Vol.5 No.4

In this paper, soil-structure interaction analysis has been presented for beams resting on multilayered geosynthetic-reinforced granular fill-soft soil system. The soft soil and geosynthetic reinforcements are idealized as nonlinear springs and elastic membranes, respectively. The governing differential equations are solved by finite difference technique and the results are presented in non-dimensional form. It is observed from the study that use of geosynthetic reinforcement is not very effective for maximum settlement reduction in case of very rigid beam. Similarly the reinforcements are not effective for shear force reduction if the granular fill has very high shear modulus value. However, multilayered reinforced system is very effective for bending moment and differential settlement reduction.

A Review of Withering in the Processing of Black Tea

Deb, Saptashish,Jolvis Pou, K.R. Korean Society for Agricultural Machinery 2016 바이오시스템공학 Vol.41 No.4

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

Stand-alone photoconversion of carbon dioxide on copper oxide wire arrays powered by tungsten trioxide/dye-sensitized solar cell dual absorbers

Deb Nath, Narayan Chandra,Choi, Seung Yo,Jeong, Hye Won,Lee, Jae-Joon,Park, Hyunwoong Elsevier 2016 Nano energy Vol.25 No.-

<P><B>Abstract</B></P> <P>A photoelectrochemical (PEC) cell composed of a WO<SUB>3</SUB>/dye-sensitized solar cell (WO<SUB>3</SUB>/DSSC) and copper oxide (Cu<SUB>x</SUB>O, where <I>x</I>=1 and 2) wire arrays as a dual-absorber photoanode and cathode, respectively, is demonstrated as a stand-alone, durable device for CO<SUB>2</SUB> photoconversion. The Cu<SUB>x</SUB>O wire arrays, which have high surface-to-volume ratios, exhibit promising electrocatalytic activity for CO<SUB>2</SUB> conversion to CO at Faradaic efficiencies of ~80% and ~60% at E=−0.2 and −0.4V <I>vs</I>. RHE, respectively, and H<SUB>2</SUB> production is minimized at a Faradaic efficiency <~20% in the potential range between −0.2 and −1.0V <I>vs</I>. RHE. The single-absorber cell of a WO<SUB>3</SUB> photoanode and Cu<SUB>x</SUB>O wire array cathode couple (WO<SUB>3</SUB>-Cu<SUB>x</SUB>O) requires a minimum overpotential of ~0.7V to drive CO<SUB>2</SUB> conversion. For stand-alone CO<SUB>2</SUB> conversion, a DSSC is coupled to the WO<SUB>3</SUB>-Cu<SUB>x</SUB>O system. In the dual-absorber cell (WO<SUB>3</SUB>/DSSC-Cu<SUB>x</SUB>O), the long-wave band (λ ><I>ca</I>. 450nm) passed through the semitransparent WO<SUB>3</SUB> film is absorbed by the dye-sensitized TiO<SUB>2</SUB> electrode of the DSSC. The WO<SUB>3</SUB>/DSSC-Cu<SUB>x</SUB>O shows a potential gain of ~0.7V and is able to successfully drive CO<SUB>2</SUB> conversion on Cu<SUB>x</SUB>O and simultaneously oxidize water on WO<SUB>3</SUB> without an external power supply. In this stand-alone system, the primary CO<SUB>2</SUB> conversion product is CO, with a solar-to-chemical energy efficiency of ~2.5%; H<SUB>2</SUB> and formate are obtained with energy efficiencies of 0.7% and 0.25%, respectively, in 5h (overall efficiency ~3.45%). Neither CO<SUB>2</SUB> conversion product nor H<SUB>2</SUB> is found using the single-absorber system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Stand-alone photoelectrochemical cell for CO<SUB>2</SUB> conversion was designed. </LI> <LI> WO<SUB>3</SUB>/DSSC and copper oxide (Cu<SUB>x</SUB>O) wire arrays were coupled as a dual-absorber photoanode and cathode, respectively. </LI> <LI> In the dual-absorber cell, the long-wave band passed through the semitransparent WO<SUB>3</SUB> film is absorbed by DSSC. </LI> <LI> The primary CO<SUB>2</SUB> conversion product is CO, with an energy efficiency of ~2.5% (overall efficiency ~3.45%). </LI> <LI> Neither CO<SUB>2</SUB> conversion product nor H<SUB>2</SUB> is produced by the single-absorber system. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

On the elastic, elastic-plastic properties of Au nanowires in the range of diameter 1-200 nm

Deb Nath, S. K.,Kim, Sung-Gaun American Institute of Physics 2012 JOURNAL OF APPLIED PHYSICS - Vol.112 No.12

DCT and DWT Based Robust Audio Watermarking Scheme for Copyright Protection

Deb, Kaushik,Rahman, Md. Ashikur,Sultana, Kazi Zakia,Sarker, Md. Iqbal Hasan,Chong, Ui-Pil The Korea Institute of Convergence Signal Processi 2014 융합신호처리학회 논문지 (JISPS) Vol.15 No.1

Digital watermarking techniques are attracting attention as a proper solution to protect copyright for multimedia data. This paper proposes a new audio watermarking method based on Discrete Cosine Transformation (DCT) and Discrete Wavelet Transformation (DWT) for copyright protection. In our proposed watermarking method, the original audio is transformed into DCT domain and divided into two parts. Synchronization code is applied on the signal in first part and 2 levels DWT domain is applied on the signal in second part. The absolute value of DWT coefficient is divided into arbitrary number of segments and calculates the energy of each segment and middle peak. Watermarks are then embedded into each middle peak. Watermarks are extracted by performing the inverse operation of watermark embedding process. Experimental results show that the hidden watermark data is robust to re-sampling, low-pass filtering, re-quantization, MP3 compression, cropping, echo addition, delay, and pitch shifting, amplitude change. Performance analysis of the proposed scheme shows low error probability rates.

Edge-carboxylated graphene nanoplatelets as efficient electrode materials for electrochemical supercapacitors

Deb Nath, Narayan Chandra,Jeon, In-Yup,Ju, Myung Jong,Ansari, Sajid Ali,Baek, Jong-Beom,Lee, Jae-Joon Elsevier 2019 Carbon Vol.142 No.-

<P><B>Abstract</B></P> <P>Edge-carboxylated graphene nanoplatelets (<B>ECG</B>), prepared by a mechano-chemical reaction (or ball milling method) in the presence of dry ice, are eligible for an efficient electrode materials for electrochemical supercapacitors. <B>ECG</B> contained a higher content of edge-carboxylic groups with less structural defects, compared with the nitrogen-doped carboxylic graphene (<B>NGOOH</B>) prepared from the conventional solution-exfoliation of graphite. The structural defects level of <B>ECG</B> is <I>ca</I>. 16.2%, while it was <I>ca</I>. 48.9% for <B>NGOOH</B>. The edge-carboxylation increases the electroactive surface area, hydrophilicity and wettability of graphene without serious deterioration of the intrinsic properties <I>e.g</I>., chemical, mechanical and electronic properties. In result, it is more effective in enabling ion adsorption and rapid electrolyte diffusion within the pores of graphene which results in a significant increase of specific capacitance (<I>C</I> <SUB>sp</SUB>) to 365.72 F/g at a current density of 1 A/g, with a good charge–discharge property and rate capability for <B>ECG.</B> On the other hand, the <I>C</I> <SUB>sp</SUB> significantly decreases to <I>ca.</I> 175.05 F/g for <B>NGOOH</B>, as its high level of structural defects seriously affected its electronic properties.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Low Frequency Band Watermarking with Weighted Correction in the Combined Cosine and Wavelet Transform Domain

Deb, Kaushik,Al-Seraj, Md. Sajib,Chong, Ui-Pil The Korea Institute of Convergence Signal Processi 2013 융합신호처리학회 논문지 (JISPS) Vol.14 No.1

A combined DWT and DCT based watermarking technique of low frequency watermarking with weighted correction is proposed. The DWT has excellent spatial localization, frequency spread and multi-resolution characteristics, which are similar to the theoretical models of the human visual system (HVS). The DCT based watermarking techniques offer compression while DWT based watermarking techniques offer scalability. These desirable properties are used in this combined watermarking technique. In the proposed method watermark bits are embedded in the low frequency band of each DCT block of selected DWT sub-band. The weighted correction is also used to improve the imperceptibility. The extracting procedure reverses the embedding operations without the reference of the original image. Compared with the similar approach by DCT based approach and DWT based approach, the experimental results show that the proposed algorithm apparently preserves superiori mage quality and robustness under various attacks such as JPEG compression, cropping, sharping, contrast adjustments and so on.

A VEHICLE LICENSE PLATE DETECTION METHOD FOR INTELLIGENT TRANSPORTATION SYSTEM APPLICATIONS

Deb, Kaushik,Jo, Kang-Hyun Taylor Francis 2009 Cybernetics and systems Vol.40 No.8

<P> Detecting license plates is crucial and inevitable in the vehicle license plate recognition system. In this article, a Hue-Saturation-Intensity (HSI) color model is adopted to select automatically statistical threshold value for detecting candidate regions. The focus of this article is on the implementation of a new method to detect candidate regions when vehicle bodies and license plates (LP) have similar color. The proposed method is able to deal with candidate regions under independent orientation and scale of the plate. For the decomposing candidate regions, predetermined LP alphanumeric characters are used by position histogram to verify and detect vehicle LP regions. Various LP images were used with a variety of conditions to test the proposed method and results proved its effectiveness.</P>

An Efficient Method of Vehicle License Plate Detection Based on HSI Color Model and Histogram

Deb, K.,Lim, H.,Kang, S.-J.,Jo, K.-H. SPRINGER-VERLAG 2009 Lecture Notes in Computer Science Vol.5579 No.-

9-cis retinoic acid improves developmental competence and embryo quality during in vitro maturation of bovine oocytes through the inhibition of oocyte tumor necrosis factor- α gene expression

Deb, G.K.,Dey, S.R.,Bang, J.I.,Cho, S.J.,Park, H.C.,Lee, J.G.,Kong, I.K. AMERICAN SOCIETY OF ANIMAL SCIENCE 2011 Journal of animal science Vol.89 No.9