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Land use change detection in Solan Forest Division,Himachal Pradesh,India

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Forest Ecosystems 2015年第4期2卷 327-338页

作者： Shipra Shah DP sharma Department of Forestry College of AgricultureFisheries and ForestryFiji National University Department of Silviculture and Agroforestry Dr.Y.S.Parmar University of Horiculture and Forestry

Background： Monitoring the changing pattern of vegetation across diverse landscapes through remote sensing is instrumental in understanding the interactions of human activities and the ecological environment. Land use pattern i the state of Himachal Pradesh in the Indian Western Himalayas has been undergoing rapid modifications due to changing cropping patterns, rising anthropogenic pressure on forests and government policies. We studied land use change in Solan Forest Division of Himachal Pradesh to assess species wise area changes in the forests of the region. Methods： The supervised classification （Maximum likelihood） on two dates of IRS （LISS III） satellite data was performed to assess land use change over the period 1998-2010. Results： Seven land use categories were identified namely, chir pine （Pinus roxburghii） forest, broadleaved forest, bamboo （Dendrocolamus strictus） forest, ban oak （Quercus leucotrichophora） forest, khair （Acacia catechu） forest, culturable blank and cultivation. The area under chir pine, cultivation and khair forests increased by 191 ha （4.55 %）, 129 ha （13.81%） and 77 ha （23.40 %）, whereas the area under ban oak, broadleaved, culturable blank and bamboo decreased by 181 ha （16.58 %）, 152 ha （6.30 %）, 71 ha （2.72 %） and 7 ha （0.47 %）, respectively. Conclusions： The study revealed a decrease in the area under forest and culturable blank categories and a simultaneous increase in the area under cultivation primarily due to the large scale introduction of horticultural cash crops in the state. The composition of forests also exhibited some major changes, with an increase in the area of commercially important monoculture plantation species such as pine and khair, and a decline in the area of oak, broadleaved and bamboo which are facing a high anthropogenic pressure in meeting the livelihood demands of forest dependent communities. In time deforestation, forest degradation and ecological imbalances due to the changing forest species compositio

关键词： Land use Solan Forest Division Supervised Classification Maximum likelihood

Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

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Plasma Science and Technology 2024年第4期26卷 94-100页

作者： Sunil KANCHI Rohit SHUKLA Archana sharma Pulsed Power and Electromagnetics Division Bhabha Atomic Research CentreVisakhapatnam 531011India Homi Bhabha National Institute Mumbai 400085India Beam Technology Development Group Bhabha Atomic Research CentreMumbai 400085India

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon *** triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

关键词： coaxial plasma source triple Langmuir probe Faraday cup plasma density plasma temperature

Optimal Eighth Order Convergent Iteration Scheme Based on Lagrange Interpolation

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 1093-1102页

作者： Rajni sharma Ashu BAHL Department of Applied Sciences D.A.V. Institute of Engineering and Technology Kabir Nagar Jalandhar 144008 India Research Scholar I.K. Gujral Punjab Technical University Jalandhar-Kapurthala Highway Kapurthala-144601 Punjab India Department of Mathematics D.A.V. College Jalandhar 144008 India

In this paper, based on fourth order Ostrowski method, we derive an optimal eighth order iteration scheme for obtaining simple roots of nonlinear equations using Lagrange interpolation and suitable weight functions. The scheme requires three evaluations of the function and one evaluation of the first derivative per iteration. Numerical examples are included to confirm the theoretical results and to show the competitive performance of the proposed iteration scheme.

关键词： nonlinear equations Ostrowski method Lagrange interpolation order of convergence efficiencyindex

Broad-band spectral study of LMXB black hole candidate 4U 1957+11 with NuSTAR

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Research in Astronomy and Astrophysics 2021年第9期21卷 11-20页

作者： Prince sharma Rahul sharma Chetana Jain Gulab CDewangan Anjan Dutta Department of Physics and Astrophysics University of DelhiDelhi 110007India Hansraj College University of DelhiDelhi 110007India Inter-University Centre for Astronomy and Astrophysics(IUCAA) Pune411007India Indian Institute of Science Education and Research(IISER)Mohali Punjab140306India

We present here the results of broadband spectral analysis of a low-mass X-ray binary and a black hole candidate 4 U 1957+*** source was observed nine times with the Nuclear Spectroscopic Telescope A rray(NuSTAR)between September 2018 and November *** these observations,the spectral state of 4 U 1957+11 evolved *** disc dominant spectra are described well with a hot,multicolor disc blackbody with disc temperature varying in the range kT_(in)~1.35-1.86 keV and a non-thermal component having a steep slope(Γ=2-3).A broad Fe emission line feature(5-8 keV)was observed in the spectra of all the *** relativistic disc model was used to study the effect of distance,inclination and the black hole mass on its *** indicate a higher spin for smaller distances and lower black hole *** smaller distances and higher masses,spin is maximum and almost independent of the *** inverse correlation exists between the spin and the spectral hardening factor for all the *** system prefers a moderate spin of about 0.85 for black hole masses between 4-6 M⊙for a 7 kpc distance.

关键词： accretion,accretion discs black hole physics X-rays:binaries X-rays:individualU 1957+11

Behavior of ring footing resting on reinforced sand subjected to eccentric-inclined loading

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 347-357页

作者： Vaibhav sharma Arvind Kumar Dr.B.R.Ambedkar National Institute of Technology Jalandhar144011India

Ring footings are suitable for the structures like tall transmission towers, chimneys, silos and oil *** types of structures are susceptible to horizontal loads(wind load) in addition to their dead *** the literature, very little or no effort has been made to study the effect of ring footing resting on reinforced sand when subjected to eccentric, inclined and/or eccentric-inclined loadings. This paper aims to study the behavior of ring footing resting on loose sand and/or compacted randomly distributed fiberreinforced sand(RDFS) when subjected to eccentric(0 B, 0.05 B and 0.1 B, where B is the outer diameter of ring footing), inclined(0°,5°,10°, 15°,-5°,-10° and-15°)and eccentric-inclined loadings by using a finite element(FE) software PLAXIS 3 D. The behavior of ring footing is studied by using a dimensionless factor called reduction factor(RF). The numerical model used in the PLAXIS 3 D has been validated by conducting model plate load tests. Moreover, an empirical expression using regression analysis has been presented which will be helpful in plotting a load-settlement curve for the ring footing.

关键词： Soil reinforcement Ring footing Numerical method Randomly distributed fibers Load inclination Load eccentricity Model tests Reduction factor(RF)

Modulation of B-cell receptor and microenvironment signaling by a guanine exchange factor in B-cell malignancies

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Cancer Biology & Medicine 2016年第2期13卷 277-285页

作者： Wei Liao Sanjai sharma Division of Hematology-Oncology Greater Los Angeles VA Healthcare Center UCLA School of Medicine

Objective： Chronic lymphocytic leukemia （CLL） and mantle cell lymphoma （MCL） cells over-express a guanine exchange factor （GEF）, Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods： N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor （BCR） and chemokine signaling pathways were compared in the Rasgrf-I over-expressing and a control transfected cell line. Results： Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions： This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.

关键词： B-ceU malignancies mantle cell lymphoma chronic lymphocytic leukemia (CLL) B-cell receptor guanine exchange factorRasgrf- 1 ERK pathway

Biodegradable polymethacrylic acid grafted psyllium for controlled drug delivery systems

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Frontiers of Chemical Science and Engineering 2013年第1期7卷 116-122页

作者： Ranvijay KUMAR Kaushlendra sharma Birla Institute of Technology Pama 800014 India

Polymethacrylic acid （PMA） was synthesized on the backbone of psyllium （Psy） by a microwave assisted method to prepare polymeric grafted materials designated as （Psy-g-PMA）. Various grades of Psy-g-PMA were prepared by changing the degree of grafting from 35%- 58% and the materials were then made into tablets. Swelling and biodegradability studies of the tablets were carried out. Acetyl salicylic acid was incorporated in the various Psy-g-PMA samples and tablets were prepared to study the in vitro drug release in acidic （pH = 4）, neutral （pH = 7）, and basic （pH = 9） media. In the acidic medium, the swelling was more than 1300%. In addition, the biodegradable Psy-g-PMA had the highest drug release in the acidic medium. This may be attributed to Fickian diffusion since the drug and the medium in which it was released have the same acidic nature.

关键词： psyllium acetyl salicylic acid in-vitro drug release swelling biodegradation

Internal transcribed spacer guided multiplex PCR for species identification of Convolvulus prostratus and Evolvulus alsinoides

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Acta Pharmaceutica Sinica B 2016年第3期6卷 253-258页

作者： Sonal sharma Neeta Shrivastava B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre Sarkhej-Gandhinagar Highway Nirma University

Shankhpushpi is a reputed drug from an Indian system of medicine for treating mental disorders and enhancing memory. Two herbs, namely Convolvulus prostratus Forssk. and Evolvulus alsinoides(L.) L., are commonly known as Shankhpushpi. Ambiguous vernacular identity can affect the scientific validity of the Shankpushpi-based herbal drug therapy. In the present investigation, a novel and sensitive multiplex PCR method based on polymorphism in the internal transcribed spacer(ITS) region was developed to establish the molecular identity of C. prostratus and E. alsinoides. DNA was isolated and the ITS region was amplified, sequenced and assembled. Sequences were aligned to identify variable nucleotides in order to develop plant-specific primers. Primers were validated in singleplex reactions and eventually a multiplex assay was developed. This assay was tested for sensitivity and validated by amplifying DNA isolated from the simulated blended powdered plant material. Primers developed for C. prostratus resulted into a 200 bp amplicon and 596 bp for E. alsinoides. The assay was found to be sensitive enough for amplification of low quantities of DNA. The method can detect 10% of the mixing of plants with each other in blended material. This PCR assay can be used for rapid botanical identification of Shankhpushpi plant materials and will improve evidence-based herbal drug therapy.

关键词： PCR Internal transcribed spacers Shankhpushpi Botanical identification Adulteration Substitution Herbal drugs DNA barcoding

Boundary conditions for porous solids saturated with viscous fluid

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Applied Mathematics and Mechanics(English Edition) 2009年第7期30卷 821-832页

作者： M.D.sharma Department of Mathematics Kurukshetra University

Boundary conditions are derived to represent the continuity requirements at the boundaries of a porous solid saturated with viscous fluid. They are derived from the physically grounded principles with a mathematical check on the conservation of energy. The poroelastic solid is a dissipative one for the presence of viscosity in the interstitial fluid. The dissipative stresses due to the viscosity of pore-fluid are well represented in the boundary conditions. The unequal particle motions of two constituents of porous aggre~ gate at a boundary between two solids are explained in terms of the drainage of pore-fluid leading to imperfect bonding. A mathematical model is derived for the partial connec- tion of surface pores at the porous-porous interface. At this interface, the loose-contact slipping and partial pore opening/connection may dissipate a part of strain energy. A numerical example shows that, at the interface between water and oil-saturated sandstone, the modified boundary conditions do affect the energies of the waves refracting into the isotropic porous medium.

关键词： porous solid dissipative boundary conditions