Reduction of noxious Cr(VI) ion to Cr(III) ion in aqueous solutions using H2O2 and UV/H2O2 systems

M.H. Dehghani,B. Heibati,A. Asadi,I. Tyagi,S. Agarwal,V.K. Gupta 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Conversion of the toxic Cr(VI) to the less toxic Cr(III) in aqueous solutions by chemical andphotochemical reduction was carried out using H2O2 and UV radiation. The whole mechanism was wellelucidated and investigated using potassium dichromate (K2Cr2O7) as a standard model compound. Theeffects of potential factors affecting the reduction efficiency were well studied and optimized, theoptimized parameters such as concentration of H2O2 (from 0.5 to 1.5 M), pH (from 5 to 9), irradiationtime (0 to 140 min) and reaction time (0 to 120 min). Initial concentration of Cr(VI) in the solution wasvaried from 0.1 to 15 mg/L plays a significant role in the mechanism involves for the reduction of noxiousCr(VI) to less toxic Cr(III).

The Development of Simple Methods for the Maintenance and Quantification of Polymyxa graminis

Tyagi, S.,Sultana, R.,Ju, H. J.,Lee, W. H.,Kim, K.,Lee, B.,Lee, K. J. Springer Science + Business Media 2016 Indian journal of microbiology Vol.56 No.4

<P>Polymyxa graminis, a root endoparasite of several cereal species, is considered to be non-pathogenic but serves as a vector of various plant viruses belonging to the genera Bymovirus, Furovirus, and Pecluvirus. Specifically, it reduces barley productivity by transmitting the Barley Yellow Mosaic Virus (BaYMV). To date, due to its obligate biotrophic property, no artificial culturing of P. graminis was reported and its quantification was also technically challenging. Here, we developed a novel and simple method to infect P. graminis within sterile barley roots in contamination free by preparing nearly pure zoospore inoculum. Such artificial maintenance of P. graminis was verified based on the presence of various developmental stages in infected barley roots under microscope. In addition, the population of resting spores in host tissue was determined by establishing standard curve between manually counted number of spores and C-t values of 18S rDNA amplification using quantitative real-time PCR. Furthermore, it was validated that standard curve generated was also applicable to estimate the abundance of P. graminis in soil environments. In conclusion, the present study would help to generate a system to investigate the etiological causes as well as management of plant diseases caused by P. graminis and BaYMV in tissue and soil.</P>

Noise Analysis of Sub Quarter Micrometer AlGaN/GaN Microwave Power HEMT

Tyagi, Rajesh K.,Ahlawat, Anil,Pandey, Manoj,Pandey, Sujata The Institute of Electronics and Information Engin 2009 Journal of semiconductor technology and science Vol.9 No.3

An analytical 2-dimensional model to explain the small signal and noise properties of an AlGaN/GaN modulation doped field effect transistor has been developed. The model is based on the solution of two-dimensional Poisson's equation. The developed model explains the influence of Noise in ohmic region (Johnson noise or Thermal noise) as well as in saturated region (spontaneous generation of dipole layers in the saturated region). Small signal parameters are obtained and are used to calculate the different noise parameters. All the results have been compared with the experimental data and show an excellent agreement and the validity of our model.

Genetic diversity assessment of Indian barley cultivars using RAPD markers

K. Tyagi,S. K. Jaiswal,L. C. Prasad,A. K. Joshi,S. J. Yun 한국작물학회 2008 한국작물학회 학술발표대회 논문집 Vol.2008 No.10

Assessment of the extent of genetic variability within a cultivated crop has important consequences in plant breeding and conservation of genetic resources. Random amplified polymorphic DNA (RAPD) markers were used to produce barley genomic DNA fingerprints. The aim of this work was to investigate the efficacy of polymorphism contained in such fingerprints on disclosing genetic relationships among 26 barley genotypes including advanced lines and released cultivars. Among the 21 primers the percentage of polymorphic bands ranged from 33% (OPG-07) to 83% (OPG-02), showing a high degree of molecular variation. The highest genetic similarity was observed between genotypes Karan-521 and Karan-741(58%), and the lowest genetic similarity was observed between the cultivars Lakhan and C 138 (3.7%). The similarity matrix by the UPGMA algorithm delineated the above genotypes into four major clusters. The results demonstrate the utility of RAPD markers in differentiating Indian barley varieties. KT and SJY were supported by 2008 National Agricultural Germplasm Management System Establishment Program.

SENSITIVIY OF A NANOCANTILEVER-BASED MASS SENSOR

K. PRABAKAR,J. JAYAPANDIAN,A. K. TYAGI,C. S. SUNDAR,BALDEV RAJ 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2010 NANO Vol.5 No.1

In the present work, mass and position sensitivity of a nanocantilever is simulated using finite element analysis. Changes in resonant frequency of various modes of a polysilicon cantilever, with a gold coating of different thickness, area, and spatial distribution is simulated. It is found that for a uniform increase in gold coating thickness, torsional mode gives an order higher mass sensitivity than vertical bending and lateral bending modes. In other cases, sensitivity is highly dependent on the position of the coating and is explained on the basis of flexural rigidity. Apart from this, simulations were performed for a point mass (gold cube) loading at various positions along the length and width axis of the cantilever. Further, for localized mass loading, cantilever was tailored for enhanced sensitivity. It is found that by introducing a step discontinuity in thickness of the cantilever, the mass sensitivity increases by two orders of magnitude and it depends on the position of step from free end, step thickness, and step width.

Genetic Variation of Drought Tolerance at Early Stage of Plant Growth in Wild Barley (Hordeum vulgare L. ssp. spontaneum) Germplasm

K. Tyagi,M. R. Park,H. J. Lee,C. A. Lee,S. J. Yun 한국작물학회 2010 한국작물학회 학술발표대회 논문집 Vol.2010 No.04

Drought is one of the most important types of abiotic stress that affects stability and amount of yield. This study was conducted to screen for drought tolerance at early seedling stages for 318 ecogeographically diverse wild barley (HordeumvulgareL.spp.spontaneum) diversity collection (WBDC). Considerable variation was observed for all the seedling characters examined. Seedling growth was significantly reduced by 17% polyethyleneglycol -induced osmotic stress with significant variation among accessions. Comparison of mean performance under normal and osmotic stress conditions indicated that shoot length was the most sensitive trait, followed by seedling length, seminal root number, root-shoot length ratio and root length. The mean of root-shoot length ratio, however, increased under osmotic stress. Correlation studies indicated that the root length was the most important trait, followed by shoot length and root-shoot length ratio. The accessions from the Fertile Crescent and North Africa showed more drought tolerance than those from the other geographical regions. The accessions WBDC009 (Jordan), WBDC075 (Libya), WBDC181 (Jordan), WBDC242 (Jordan) and WBDC280 (Israel) exhibited the lowest stress susceptibility index ‘S’ values. Consequently, these accessions showed tolerance to drought at the early seedling stage and are considered to be good sources of drought tolerance for cultivated barley improvement. This work was supported by a grant from Regional Subgenebank Support Program of Rural Development Administration, Republic of Korea .

Pre- and post-breakdown electrical studies in ultrathin Al2O3 films by conductive atomic force microscopy

K. Ganesan,S. Ilango,Mariyappan Shanmugam,M. Farrokh Baroughi,M. Kamruddin,A.K. Tyagi 한국물리학회 2013 Current Applied Physics Vol.13 No.9

The loss of local dielectric integrity in ultrathin Al2O3 films grown by atomic layer deposition is investigated using conducting atomic force microscopy. IeV spectra acquired at different regions of the samples by constant and ramping voltage stress are analyzed for their pre- and post-breakdown signatures. Based on these observations, the thickness dependent dielectric reliability and failure mechanism are discussed. Our results show that remarkable enhancement in breakdown electric field as high as 130 MV/cm is observed for ultrathin films of thickness less than 1 nm.

Tracing the footprints of the ABCDE model of flowering in Phalaenopsis equestris (Schauer) Rchb.f. (Orchidaceae)

Jaspreet K. Sembi,Himani,Thakku R. Ramkumar,Shivi Tyagi,Himanshu Sharma,Santosh K. Upadhyay 한국식물생명공학회 2019 JOURNAL OF PLANT BIOTECHNOLOGY Vol.46 No.4

Orchids are indispensable to the floriculture industry due to their unique floral organization. The flowers have two outer whorls of tepals including a lip (labellum), and two inner whorls, pollinia and gynostemiun (column). The floral organization and development is controlled at the molecular level, mainly by the MADS-box gene family, comprising homeotic genes divided into type I and type II groups. The type I group has four sub-groups, Mα, Mβ, Mγ, and Mδ, playing roles in seed, embryo, and female repro-ductive organ development; the type II group genes form classes A, B, C, D, and E, which are a part of the MIKCC subgroup with specific roles in florigenesis and organization. The coordinated functioning of these classes regulates the development of various floral whorls. The availability of genome and transcriptome sequence data for Phalaenopsis equestris offers an opportunity to validate the ABCDE model of flower development. Hence, this study sought to characterize the MADS-box gene family and elucidate of the ABCDE model. A total of 48 identified MADS-box proteins, including 20 type I [Mα (12), Mγ (8)] and 28 type II [MIKCC (27), MIKC* (1)] members, were characterized for physico-chemical features and domains and motifs organization. The exon-intron distribution and the upstream cis-regulatory elements in the promoter regions of MADS-box genes were also analysed. The discrete pace of duplication events in type I and type II genes suggested differential evolutionary constraints between groups. The correlation of spatio-temporal expression pattern with the presence of specific cis-regulatory elements and putative protein–protein interaction within the different classes of MADS-box gene family endorse the ABCDE model of floral development.

Noise Analysis of Sub Quarter Micrometer AlGaN/GaN Microwave Power HEMT

Rajesh K. Tyagi,Anil Ahlawat,Manoj Pandey,Sujata Pandey 대한전자공학회 2009 Journal of semiconductor technology and science Vol.9 No.3

An analytical 2-dimensional model to explain the small signal and noise properties of an AlGaN/GaN modulation doped field effect transistor has been developed. The model is based on the solution of twodimensional Poisson’s equation. The developed model explains the influence of Noise in ohmic region (Johnson noise or Thermal noise) as well as in saturated region (spontaneous generation of dipole layers in the saturated region). Small signal parameters are obtained and are used to calculate the different noise parameters. All the results have been compared with the experimental data and show an excellent agreement and the validity of our model.

One Point In situ Incubation Estimation of Undegraded Protein in Forages

Gupta, Neeraj,Tyagi, A.K.,Singhal, K.K. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.11

To estimate undegraded intake protein (UIP) fraction in feeds and fodders, on the basis of their neutral detergent insoluble N content was studied. Samples of six feeds and forages were incubated in situ for a time equivalent to their mean retention time, estimated on the basis of their digestibility plus 10 h (to account for a lag in passage of particles from the rumen). The samples were incubated for 0, 25, 50, 75 and 100% of the estimated total mean retention time. UIP value of leguminous forages, obtained from the fractional rates of degradation and passage, were highly correlated with those estimated from samples incubated for 75% of total mean retention time, while incubating the non-leguminous forages and groundnut cake for this point over estimate the UIP fraction.