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Proterozoic orogenic belts and rifting of Indian cratons: Geophysical constraints

Geoscience Frontiers 2014年第1期5卷 25-41页

作者： D.C.Mishra M.ravi kumar National Geophysical research Institute (CSIr) Gravity GroupHyderabad 500007 India Indian Institute of Geomagnetism Navi Mumbai 410218 India

The Aravalli-Delhi and Satpura Mobile Belts （ADMB and SMB） and the Eastern Ghat Mobile Belt （EGMB） in India form major Proterozoic mobile belts with adjoining cratons and contemporary basins. The most convincing features of the ADMB and the SMB have been the crustal layers dipping from both sides in opposite directions, crustal thickening （ -45 km） and high density and high conductivity rocks in upper/ lower crust associated with faults/thrusts. These observations indicate convergence while domal type re- flectors in the lower crust suggest an extensional rifting phase. In case of the SMB, even the remnant of the subducting slab characterized by high conductive and low density slab in lithospheric mantle up to - 120 km across the Purna-Godavari river faults has been traced which may be caused by fluids due to metamorphism. Subduction related intrusives of the SMB south of it and the ADMB west of it suggest N-S and E-W directed convergence and subduction during Meso-Neoproterozoic convergence. The simultaneous E-W conver- gence between the Bundelkhand craton and Marwar craton （Western rajasthan） across the ADMB and the N-S convergence between the Bundelkhand craton and the Bhaodara and Dharwar cratons across the SMB suggest that the forces of convergence might have been in a NE SW direction with E-W and N-S compo- nents in the two cases, respectively. This explains the arcuate shaped collision zone of the ADMB and the SMB which are connected in their western part. The Eastern Ghat Mobile Belt （EGMB） also shows signatures orE -W directed Meso Neoproterozoic convergence with East Antarctica similar to ADMB in north India. Foreland basins such as Vindhyan （ADMB-SMB）, and k.rnool （EGMB） Supergroups of rocks were formed during this convergence. Older rocks such as Aravalli （ADMB）, Mahakoshal-Bijawar （SMB）, and Cuddapah （EGMB） Supergroups of rocks with several basic/ultrabasic intrusives along these mobile belts, plausibly formed during an earlier episode of rifting during

关键词： Indian Shield Convergence Collision rifting Geophysical anomalies

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Evaluation of Codebook Design Using SCMA Scheme Based on A_(n) and D_(n) Lattices

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Intelligent Automation & Soft Computing 2023年第3期35卷 3037-3048页

作者： G.rajamanickam G.ravi Department of ECE Knowledge Institute of TechnologySalem637504India Department of ECE Sona College of TechnologySalem636001India

The sparse code multiple access(SCMA)scheme is a Non-Orthogonal Multiple Access(NOMA)type of scheme that is used to handle the uplink com-ponent of mobile communication in the current generation.A need of the 5G mobile network is the ability to handle more *** accommodate this,the SCMA allows each user to deploy a variety of sub-carrier broadcasts,and several consumers may contribute to the same frequency using superposition *** SCMA approach,together with codebook design for each user,is used to improve channel efﬁciency through better management of the available ***-ever,developing a codebook with a greater number of value sets is still another *** enhanced techniques of encoding and decoding for 5G networks,mapping the multidimensional constellations in the SCMA system plays a signif-icant role in improving the system performance and enhancing the overall system *** creation of a codebook utilizing the SCMA approach in con-junction with the lattice theory is suggested in this *** prototype is shaped using a popular lattice,such as A n and D n,as the ***,from the primary lattice constellation,the multidimensional complex mother constellation with the most noticeable variance in power is *** lattice-based cod-ing is generated by combining the codebooks with the mother constellation,and the codes in the matrices are mapped by rotating the constellations in this *** suggested technique,in conjunction with the investigation of novel SCMA codebook sets,provides improved performance in terms of Bit Error rate(BEr)and complexity with regard to Signal to Noise ratio(SNr).Finally,the bit error rate is reduced for various SNrs during transmission in the channel.

关键词： 5G NOMA SCMA lattice coding codebook design bit error rate

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Perspectives on the clinical development of mmunotherapy in prostate cancer

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Asian Journal of Andrology 2018年第3期20卷 253-259页

作者： Lisa M Cordes James L Gulley ravi A Madan Clinical Center National Institutes of Health Bethesda MD 20892 USA Genitourinary Malignancies Branch Center for Cancer Research National Cancer Institute National Institutes of Health Bethesda MD 20892 USA

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. SipuleuceI-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomark.rs, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.

关键词： checkpoint inhibitor immunotherapy prostate cancer therapeutic vaccine

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Variations in body melanisation, ovariole number and fecundity in highland and lowland populations of Drosophila melanogaster from the Indian subcontinent

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Insect Science 2008年第6期15卷 553-561页

作者： Subhash rajpurohit ravi Parkash Seema ramniwas Shama Singh Department of Biochemistry and Genetics Maharshi Dayanand University Rohtak 124001 India

We investigated geographical variations in three fitness-related traits （body melanisation, ovariole number and fecundity） in laboratory-reared offspring of 10 populations of Drosophila melanogaster. The populations were collected from adjacent lowland and highland localities （-80-100 km apart） in the tropical as well as subtropical regions （11.15-31.06°N） covering a linear distance about 3 000 kilometers from south to north on the Indian subcontinent. Persistence of within- as well as between-population differences at 21 ℃ suggest that observed variations in fitness-related traits have a genetic basis. Populations from higher altitudes showed consistently higher trait values （1.4-fold increase） as compared with their corresponding lowland populations. By contrast, latitudinal variations were about two-fold higher across the entire continent. Along latitude as well as altitude, population means showed higher correlation values （r 〉 0.98） between all the three fitness traits. However, on the basis of within-population analysis （assorted dark.r and lighter flies）, changes in body melanisation were significantly correlated with fecundity but not with ovariole number. Thus, analysis of within-population trait variability should be preferred as compared with data on population means for adaptive significance of fitness-related traits. In the present study, the role of climatic selection is evident from regression analysis with changes in annual average temperature of the sites of origin of populations along latitude as well as altitude.

关键词： altitude body melanisation Drosophila melanogaster fecundity latitude ovariole number

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Adaptive associations between total body color dimorphism and climatic stress-related traits in a stenothermal circumtropical Drosophila species

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Insect Science 2012年第2期19卷 247-262页

作者： ravi Parkash Jyoti Chahal Vineeta Sharma kapil Dev Department of Genetics Maharshi Dayanand UniversityRohtakIndia

Low desiccation resistance of Drosophila ananassae reflects its rarity outside the humid tropics. However, the ability of this sensitive species to evolve under seasonally varying subtropical areas is largely unknown. D. ananassae flies are mostly lighter during the rainy season but dark.r and lighter flies occur in the autumn season in northern India. We tested the hypothesis whether seasonally varying alternative body color phenotypes of D. ananassae vary in their levels of environmental stress tolerances and mating behavior. Thus, we investigated D. ananassae flies collected during rainy and autumn seasons for changes in body melanization and their genetic basis, desiccation-related traits, cold tolerance and mating propensity. On the basis of genetic crosses, we found total body color dimorphism consistent with a single gene model in both sexes olD. ananassae. A significant increase in the frequency of the dark morph was observed during the drier autumn season, and body color phenotypes showed significant deviations from Hardy-Weinberg equilibrium, which suggests climatic selection plays a role. resistance to desiccation as well as cold stress were two- to three-fold higher in the dark body color strain as compared with the light strain. On the basis of no-choice mating experiments, we observed significantly higher assortative matings between dark morphs under desiccation or cold stress, and between light morphs under hot or higher humidity conditions. To the best of our knowledge, this is the first report on the ecological significance of seasonally varying total body color dimorphism in a tropical species, D. ananassae.

关键词： assortative matings cold tolerance dark and the light morph desiccation resistance Drosophila ananassae seasonal adaptations

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CCD photometry of W UMa-type contact binaries in the old open cluster Berkeley 39

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research in Astronomy and Astrophysics 2011年第12期11卷 1469-1481页

作者： Yellapragada ravi k.ron kandulapati Sriram Pasagada Vivekananda rao Department of Astronomy Osmania University k.rea Astronomy and Space Science Institute

We present the combined BVI multicolor photometric solutions of seven EW variables in the old open cluster Berkeley 39. The observations were carried out in the B and V passbands from the 2 m telescope at the IUCAA-Girawali Observatory in India. The analysis is done using the 2003 version of the Wilson-Devinney code and the fitted light curves are presented. The light curves appear to be symmetric in all the passbands. The photometric solutions suggest that the variables are W-type systems. The new ephemeris indicates that the orbital periods of the studied variables have not changed during the timespan of observations. revised orbital period, absolute mass, radius and luminosity of the respective variables are presented. The absolute physical parameters of the variables follow the trend of field EW stars. Comparing the results obtained with the other theoretical works, we suggest that there is an excess loss of mass and angular momentum in these systems which may be due to their short period and relatively young age, possibly due to the presence of a third component or the initial detached period being less than 2 d.

关键词： binaries -- eclipsing: contact: W UMa stars

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Low-cost and versatile integration of microwire electrodes and optical waveguides into silicone elastomeric devices using modified xurographic methods

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Microsystems & Nanoengineering 2017年第1期3卷 107-113页

作者： Juncong Liu James B Mahony Ponnambalam ravi Selvaganapathy Department of Mechanical Engineering McMaster UniversityHamiltonOntario L8S 4L7Canada Department of Pathology and Molecular Medicine McMaster UniversityHamiltonOntario L8S 4K1Canada School of Biomedical Engineering McMaster UniversityHamiltonOntario L8S4K1Canada

Microelectrodes are used in microfluidic devices for a variety of purposes such as heating,applying electric fields,and electrochemical ***,they are still manufactured by expensive deposition techniques such as sputtering or evaporation and patterned using photolithography *** recently,alternate methods including nanoparticle sintering and use of liquid metal flowing through microchannels have been used to fabricate *** methods are limited in the material choices or require post processing to be integrated into *** we developed a low-cost and versatile method to integrate high-quality metal microwires into polydimethylsiloxane(PDMS)using *** microwire integration process includes cutting slit pattern on PDMS substrate and subsequent writing metal microwires into the slit pattern using a specialized *** the microwire-integrated PDMS was sealed/bonded using uncured PDMS *** method enables integration of metal microwires of diameter as small as 15μm into PDMS *** of multiple microwires with minimum spacing of 150μm has also been *** versatility of this method is demonstrated by the fabrication of metal microwire suspended in the middle of the microchannel,which is difficult to achieve using conventional electrode fabrication *** low-cost method avoids expensive clean room fabrication yet producing high-quality electrodes and can be used in a variety of microfluidic and MEMS applications.

关键词： lab on a chip microelectrode polydimethylsiloxane(PDMS) xurography

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Effect of Notch Location on Fatigue Life Prediction of Strength Mismatched HSLA Steel Weldments

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Journal of Materials Science & Technology 2004年第2期20卷 129-135页

作者： S.ravi V.Balasubramanian S.Nemat Nasser Department of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaDepartment of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaCentre of Excellence for Advanced Materials University of California at San Diego La Jolla CA 92093-0416 USA

Welding of high strength low alloy steels (HSLA) involves usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In the present investigation, the fatigue crack growth behaviour of weld metal (WM) and heat affected zone (HAZ) regions of under matched (UM), equal matched (EM) and over matched (OM) joints has been studied. The base material used in this investigation is HSLA-80 steel of weldable grade. Shielded metal arc welding (SMAW) process has been used to fabricate the butt joints. Centre cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behaviour of the welded joints. Fatigue crack growth experiments have been conducted using servo hydraulic controlled fatigue testing machine at constant amplitude loading (r=0).A method has been proposed to predict the fatigue life of HSLA steel welds using fracture mechanics approach by incorporating influences of mismatch ratio (MMr) and notch location.

关键词： Shielded metal arc welding High strength low alloy steel Mismatch ratio Notch location Fatigue crack growth Fatigue life

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Bioavailability of Arsenic and Antimony in Terrestrial Ecosystems:A review

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Pedosphere 2019年第6期29卷 681-720页

作者： Saeed BAGHErIFAM Trevor CBrOWN Christopher MFELLOWS ravi NAIDU Chemistry-School of Science and Technology University of New EnglandArmidale NSW 2351(Australia Global Centre for Environmental remediation Faculty of Science and Inform ation TechnologyUniversity o f NewcastleUniversity DriveCallaghan N S W 2308(Australia

Arsenic (As) and antimony (Sb) are metalloids that belong to group 15 of the periodic table and exhibit toxic properties in the environment. They mostly occur naturally at low concentrations in soil, although these can be significantly elevated in both aquatic and terrestrial food chains as a result of dispersion from anthropogenic sources, e.g ., mining activities. The bioavailability, i.e., the proportion of the contaminant in soil and dust that is available for uptake by plants and other living organisms, presents the greatest risk to terrestrial ecosystems. Various in vivo and in vitro methods have been used to measure As and Sb bioaccessibility in soil and dust. In vivo measurement of bioavailability can be time consuming, expensive, and unethical;thus, in vitro methods are commonly preferred. However, there is considerable uncertainty around the efficacy of in vitro tools used to measure the bioavailable fractions of As and Sb. The results of these methods are dependent on many variables, e.g., soil characteristics, contaminant sources, and chemical composition of in vitro methods. Therefore, substantial variations are observed between in vitro and in vivo results obtained from different test animals and endpoints. In this paper, we review the literature on As and Sb bioavailability in terrestrial ecosystems and current in vivo and in vitro techniques used for assessing bioavailability and bioaccessibility of metalloids. This would reveal research gaps and allow scientists and environmental policy mak.rs to gain a deeper understanding of the potential risks associated with these metalloids in the environment.

关键词： Bioaccessibility Bioavailable fraction Contamination Environmental risk assessment Metalloids Phytoavailability relative bioavailability Soil characteristics Toxicant

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Photometric study of W UMa type binaries in the old open cluster Berkeley 39

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research in Astronomy and Astrophysics 2009年第10期9卷 1149-1154页

作者： kandulapati Sriram Yellapragada ravi k.ron Pasagada Vivekananda rao Department of Astronomy Osmania University

The study of W UMa binary systems gives a wealth of information about their nature as well as their parent bodies （if any）, like clusters. In this paper, we present the I passband photometric solutions of four W UMa binaries in the open cluster Berkeley 39 using the latest version of the W-D program. The result shows that two binary systems are W-subtype W UMa binary systems and the other two systems are H-subtype W UMa binary systems. No third body has been found in any of the four systems. We found a correlation between the period and mass-ratio as well as temperature and mass-ratio for the respective variables, which is similar to the relationship between mass ratio and total mass of the contact binaries as shown by van＇t Veer and Li et al.

关键词： binaries eclipsing -- binaries close

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