Effect of Chemical Modifications on Surface Morphological, Structural, Mechanical, and Thermal Properties of Sponge-gourd Natural Fiber

Taimur-Al-Mobarak,M. F. Mina,M. A. Gafur,A. N. Ahmed,S. A. Dhar 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

Sponge-gourd (SG) natural fibers obtained from Luffa cylindrica plant were chemically treated separately using alkali (5, 10, and 15 wt%), acetic anhydride (5, 10, and 15 wt%), and benzoyl chloride (5, 10, and 15 wt%). Both untreated and chemically treated SG fibers (SGFs) were subsequently characterized using a field emission scanning electronmicroscope, a Fourier transform infrared spectrometer, an X-ray diffractometer, a universal testing machine, and a thermogravimetric analyzer. Surface analysis by scanning electron microscopy shows that the alkali treatments promote better outer surface layer than other treatments of the SGF with the exposition of inner fibrillar structure, thereby increasing roughness of the fiber surface. Alkali treatment also improves the crystallinity and exhibits new chemical bond formation inthe SGF. The tensile strength and Young’s modulus have been analyzed through a two-parameter Weibull distribution model, where a significant increase in mechanical property of benzoylated fibers has been observed. The thermal stability of the modified fibers is also found to increase by acetic anhydride treatment.

A 52 MHz 1.5V 16 Bit High Performance Shifter Circuit

Maharatna,K.,Dhar,A. S.,Banerjee,s. 대한전자공학회 1997 ICVC : International Conference on VLSI and CAD Vol.5 No.1

A 16 bit high prerformance shiner circuit has bean designed using C3DM (Philips) 1.6 ㎛ double layer CMOS technology with threshold voltage 0.7V for 1.5V application. The simulated delay is 19 nsec and power dissipation (at 52 MHz) be 0.209 mW and 2.33 mW at 1.5V and 5V supply respectively as extracted from the layout.

Conservation and Diversification of the SHR-SCR-SCL23 Regulatory Network in the Development of the Functional Endodermis in Arabidopsis Shoots

Yoon, E.K.,Dhar, S.,Lee, M.H.,Song, J.H.,Lee, S.A.,Kim, G.,Jang, S.,Choi, J.W.,Choe, J.E.,Kim, J.H.,Lee, M.M.,Lim, J. Oxford University Press 2016 Molecular plant Vol.9 No.8

Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT (SHR), SCARECROW (SCR), and SCARECROW-LIKE 23 (SCL23). Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for specification of the endodermis (known as the bundle sheath) in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein complexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feedback loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morphological analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis (known as the starch sheath) in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.

Manual Liquid Based Cytology in Primary Screening for Cervical Cancer - a Cost Effective Preposition for Scarce Resource Settings

Nandini, N.M.,Nandish, S.M.,Pallavi, P.,Akshatha, S.K.,Chandrashekhar, A.P.,Anjali, S.,Dhar, Murali Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Conventional pap smear (CPS) examination has been the mainstay for early detection of cervical cancer. However, its widespread use has not been possible due to the inherent limitations, like presence of obscuring blood and inflammation, reducing its sensitivity considerably. Automated methods in use in developed countries may not be affordable in the developing countries due to paucity of resources. On the other hand, manual liquid based cytology (MLBC) is a technique that is cost effective and improves detection of precursor lesions and specimen adequacy. Therefore the aim of the study was to compare the utility of MLBC with that of CPS in cervical cancer screening. A prospective study of 100 cases through MLBC and CPS was conducted from October 2009 to July 2010, in a Medical College in India, by two independent pathologists and correlated with histopathology (22 cases). Morphological features as seen through MLBC and CPS were compared. Subsequently, all the cases were grouped based on cytological diagnosis according to two methods into 10 groups and a subjective comparison was made. In order to compare the validity of MLBC with CPS in case of major diagnoses, sensitivity and specificity of the two methods were estimated considering histological examination as the gold standard. Increased detection rate with MLBC was 150%. The concordance rate by LBC/histopathology v/s CPS/histopathology was also improved (86% vs 77%) The percentage agreement by the two methods was 68%. MLBC was more sensitive in diagnosis of LSIL and more specific in the diagnosis of inflammation. Thus, MLBC was found to be better than CPS in diagnosis of precursor lesions. It provided better morphology with increased detection of abnormalities and preservation of specimen for cell block and ancillary studies like immunocytochemistry and HPV detection. Therefore, it can be used as alternative strategy for cervical cancer prevention in limited resource settings.

Influence of Bi and N related impurity states on the band structure and band offsets of GaSbBiN alloys

D.P. Samajdar,Utsa Das,A.S. Sharma,Subhasis Das,S. Dhar 한국물리학회 2016 Current Applied Physics Vol.16 No.12

The perturbed band structure of a proposed material GaSbBiN, formed by the incorporation of N and Bi in GaSb, is calculated using a 16 band k·p Hamiltonian. The changes in band gap (Eg), spin-orbit splitting energy (DSO), conduction band offset (DEc) and valence band offset (DEv) are investigated as functions of N and Bi mole fractions. In the low temperature regime, the addition of Bi and N to GaSb causes substantial reduction in the band gap and enhances the spin-orbit splitting energy, thereby making Eg < DSO which is expected to improve the thermal stability and high-temperature efficiency of photonic devices by the suppression of different loss mechanisms. The values of DEc and DEv for GaSbBiN alloys, calculated with reference to the host GaSb lattice, increase with the increase in Bi and N concentrations. Calculations indicate that DEc > DEv which is required for electron confinement in order to get improved temperature-insensitive characteristics of optoelectronic devices.

Benzothiazinones Kill Mycobacterium tuberculosis by Blocking Arabinan Synthesis

Makarov, V.,Manina, G.,Mikusova, K.,Mollmann, U.,Ryabova, O.,Saint-Joanis, B.,Dhar, N.,Pasca, M. R.,Buroni, S.,Lucarelli, A. P.,Milano, A.,De Rossi, E.,Belanova, M.,Bobovska, A.,Dianiskova, P.,Kordula American Association for the Advancement of Scienc 2009 Science Vol.324 No.5928

<P>New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe the synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class of antimycobacterial agents that kill Mycobacterium tuberculosis in vitro, ex vivo, and in mouse models of TB. Using genetics and biochemistry, we identified the enzyme decaprenylphosphoryl-beta-d-ribose 2'-epimerase as a major BTZ target. Inhibition of this enzymatic activity abolishes the formation of decaprenylphosphoryl arabinose, a key precursor that is required for the synthesis of the cell-wall arabinans, thus provoking cell lysis and bacterial death. The most advanced compound, BTZ043, is a candidate for inclusion in combination therapies for both drug-sensitive and extensively drug-resistant TB.</P>

High yield strength bulk Ti based bimodal ultrafine eutectic composites with enhanced plasticity

Misra, D. K.,Rakshit, R. K.,Singh, M.,Shukla, P. K.,Chaturvedi, K. M.,Sivaiah, B.,Gahtori, B.,Dhar, A.,Sohn, S. W.,Kim, W. T.,Kim, D. H. BUTTERWORTH - HEINEMANN 2014 MATERIALS AND DESIGN Vol.58 No.-

Ti-based bulk metallic glass (BMGs) and their bimodal composites are linked with the pronounced strain hardening after yielding but with much low value of strength. Therefore, developing Ti-based alloys with high yield strength and high plasticity is the current challenge. Here, we report the synthesis of ultra-fine grained bulk (UFG) (Ti0.705Fe0.295) 100 Ga-x(x) (0 <= x <= 2) bimodal eutectic composites with not only high strength and larger plasticity but also with high yield strength which is one of the important mechanical property for structural application. Reasonably high strength, high yield strength, strain to failure ratio, and enhanced plasticity of similar to 7 +/- 0.8% was observed in (Ti70.5Fe29.5)(98)Ga-2 composite which is superior than Ti-based BMGs and bimodal composites. Modification of degree of eutectic structure refinement and volume fraction of constituent phases with the addition of Ga are the crucial factors in enhancing the mechanical properties of Ti-Fi-(Ga) composites. (C) 2014 Elsevier Ltd. All rights reserved.