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Synthesis of Aligned ZnO Nanorod Array on Silicon and Sapphire Substrates by Thermal Evaporation Technique

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Journal of Materials Science & Technology 2011年第8期27卷 701-706页

High density ZnO nanorods were grown by thermal evaporation of Zn powder at 700℃ on Si （100） and sapphire （0001） substrates at atmospheric pressure without adding any catalyst. The nanorods were characterizated in terms of their structural and optical properties. The nanorods grown on Si have a diameter of 350-400 nm and a length of 1.2 μm while those on sapphire have a diameter of 600-800 nm and a length of 2.5 μm. During the structural characterization, it is noticed that the rods grow along the （0002） plane with perfect hexagonal facet. The room temperature photoluminescence spectrum showed a strong UV emission peak at 385 nm with a weak green band emission, which confirms that nanorods have good optical properties. It is observed that the oxygen partial pressure plays an important role to control the shape and size of the nanorods in thermal evaporation growth technique.

关键词： Thermal evaporation technique ZnO nanorods X-ray diffraction Photoluminescence

Effect of Oxygen Admittance Temperature on the Growth of ZnO Microcrystals by Thermal Evaporation Technique

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Journal of Materials Science & Technology 2012年第4期28卷 317-320页

作者： K.M.K. Srivatsa deepak chhikara M. Senthil Kumar Physics of Energy Harvesting Division National Physical Laboratory Council of Scientific & Industrial Research (CSIR) New Delhi 110012 India

Hexagonally well-faceted microcrystals of ZnO have been grown by thermal evaporation of Zn powder in oxygen ambient at 700℃ under atmospheric pressure. It has been observed that the properties （size and quality） of ZnO microcrystals have a strong dependence on the reactor temperature at which the oxygen gas is admitted into the growth zone. The microcrystals grown with oxygen admittance at 450℃ have a length of 1 μm and a diameter of 0.75 μm while that grown with oxygen admittance at 600 ℃ have a length of 1.5-2 μm and a diameter of 1 μm. Room temperature photoluminescence spectra show a ultraviolet （UV） emission peak at 385 nm with a green band emission at around 500 nm. The UV-to-green band emission ratio for the microcrystals grown with oxygen admittance at 450℃ is observed to be 1.25 and the ratio decreases to 0.45 for the sample grown with oxygen admittance at 600℃.

关键词： ZnO microcrystals Thermal evaporation Scanning electron microscopy Transmission electron microscopy Room temperature photoluminescence

Conditional Congruence Closure over Uninterpreted and Interpreted Symbols

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Journal of Systems Science & Complexity 2019年第1期32卷 317-355页

作者： KAPUR deepak Department of Computer Science University of New Mexico

A framework for generating congruence closure and conditional congruence closure of ground terms over uninterpreted as well as interpreted symbols satisfying various properties is proposed. It is based on some of the key concepts from Kapur's congruence closure algorithm(RTA97)for ground equations based on introducing new symbols for all nonconstant subterms appearing in the equation set and using ground completion on uninterpreted constants and puri?ed equalities over interpreted symbols belonging to different theories. In the original signature, the resulting rewrite systems may be nonterminating but they still generate canonical forms. A byproduct of this framework is a constant Horn completion algorithm using which ground canonical Horn rewrite systems can be generated for conditional ground *** effcient algorithms for generating congruence closure of conditional and unconditional equations on ground terms over uninterpreted symbols are presented. The complexity of the conditional congruence closure is shown to be O(n*log(n)), which is the same as for unconditional ground *** proposed algorithm is motivated by our attempts to generate effcient and succinct interpolants for the quanti?er-free theory of equality over uninterpreted function symbols which are often a conjunction of conditional equations and need additional simpli?cation. A completion algorithm to generate a canonical conditional rewrite system from ground conditional equations is also presented. The framework is general and ?exible and is used later to develop congruence closure algorithms for cases when function symbols satisfy simple properties such as commutativity, nilpotency, idempotency and identity as well as their combinations. Interesting outcomes include algorithms for canonical rewrite systems for ground equational and conditional theories on uninterpreted and interpreted symbols leading to generation of canonical forms for ground terms, constrained terms and Horn equat

关键词： Completion congruence closure conditional congruence closure intepreted symbols rewrit-ing uninterpreted symbols

Comprehensive G?bner Basis Theory for a Parametric Polynomial Ideal and the Associated Completion Algorithm

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Journal of Systems Science & Complexity 2017年第1期30卷 196-233页

作者： KAPUR deepak Department of Computer Science University of New Mexico Albuquerque NM USA.

Groebner basis theory for parametric polynomial ideals is explored with the main objec- tive of nfinicking the Groebner basis theory for ideals. Given a parametric polynomial ideal, its basis is a comprehensive GrSbner basis if and only if for every specialization of its parameters in a given field, the specialization of the basis is a GrSbnerbasis of the associated specialized polynomial ideal. For various specializations of parameters, structure of specialized ideals becomes qualitatively different even though there are significant relationships as well because of finiteness properties. Key concepts foundational to GrSbner basis theory are reexamined and/or further developed for the parametric case：（i） Definition of a comprehensive Groebner basis, （ii） test for a comprehensive GrSbner basis, （iii） parameterized rewriting, （iv） S-polynomials among parametric polynomials, （v） completion algorithm for directly computing a comprehensive Groebner basis from a given basis of a parametric ideal. Elegant properties of Groebner bases in the classical ideal theory, such as for a fixed admissible term ordering, a unique GrSbner basis can be associated with every polynomial ideal as well as that such a basis can be computed from any Groebner basis of an ideal, turn out to be a major challenge to generalize for parametric ideals; issues related to these investigations are explored. A prototype implementation of the algorithm has been successfully tried on many examples from the literature.

关键词： Comprehensive GrSbner basis minimal comprehensive GrSbner basis parametric polyno-mial system parametric S-polynomial redundancy.

Impact of surface Albedo on Martian photochemistry

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Earth and Planetary Physics 2020年第3期4卷 206-211页

作者： deepak Singh Physical Research Laboratory AhmedabadIndia

Solar energy is the primary driving force behind a planet’s climate system,and surface albedo plays a key role in determining the energy budget of the *** the Snow,Ice,and Aerosol Radiation(SNICAR)with the Laboratoire de Météorologie Dynamique(LMD)Mars General Circulation Model(MGCM)to create a new coupled model leads to an approximately 4%drop in the net CO2 ice deposition on *** simulated surface albedo affects the concentration of gaseous species in the Martian atmosphere(condensation-sublimation cycle).The new set-up also impacts the solar energy available in the *** two effects together lead to subsequent and significant changes in other chemical species in the Martian *** with results of the MGCM model alone,in the new coupled model CO2(gas)and O3 show a drop of about 1.17%and 8.59%in their respective concentrations,while H2O(vapor)and CO show an increase of about 13.63%and 0.56%in their respective *** trace species,OH shows a maximum increase of about 29.44%,while the maximum drop of 11.5%is observed in the O *** neutral species such as Ar and N2 remain unaffected by the albedo changes.

关键词： Mars Albedo snow photochemistry climate modelling

Effectiveness of state incentives for promoting wind energy： A panel data examination

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Frontiers in Energy 2015年第3期9卷 247-258页

作者： deepak SANGROYA Jogendra NAYAK Department of Management Studies Indian Institute of Technology IIT Roorkee Roorkee 247667 India

Over the last decade, India has started to concentrate earnestly on renewable energy. The Indian government, as well as different state governments, are adopting policy instruments such as feed in tariff, captive consumption, renewable purchase obligation and genera- tion based incentive etc. aimed at renewable energy development. This paper evaluates the effectiveness of state level incentives for the development of wind energy in India. Fixed effect panel data modelling technique of econometric analysis is used to analyse the data of 26 Indian states in 11 years. The results show that feed in tariff and captive consumption are the significant predictors of wind energy development. However, renewable purchase obligation does not affect wind energy significantly.

关键词： India wind energy development state incen-tives econometric analysis panel data

Design optimization of first wall and breeder unit module size for the Indian HCCB blanket module

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Plasma Science and Technology 2018年第6期20卷 200-210页

作者： deepak SHARMA Paritosh CHAUDHURI Institute for Plasma Research Bhat Gandhinagar Gujarat-382428 India

The Indian test blanket module（TBM） program in ITER is one of the major steps in the Indian fusion reactor program for carrying out the R＆D activities in the critical areas like design of tritium breeding blankets relevant to future Indian fusion devices（ITER relevant and DEMO）.The Indian Lead–Lithium Cooled Ceramic Breeder（LLCB） blanket concept is one of the Indian DEMO relevant TBM,to be tested in ITER as a part of the TBM ***-Cooled Ceramic Breeder（HCCB） is an alternative blanket concept that consists of lithium titanate（Li_2TiO_3） as ceramic breeder（CB） material in the form of packed pebble beds and beryllium as the neutron ***,attentions are given to the optimization of first wall coolant channel design and size of breeder unit module considering coolant pressure and thermal loads for the proposed Indian HCCB blanket based on ITER relevant TBM and loading *** analyses will help proceeding further in designing blankets for loads relevant to the future fusion device.

关键词： first wall blanket breeder unit thermal hydraulics structural analysis HCCB(helium-cooled ceramic breeder)

ON INVARIANT CHECKING

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Journal of Systems Science & Complexity 2013年第3期26卷 470-482页

作者： ZHANG Zhihai KAPUR deepak School of Mathematical Sciences Peking University Department of Computer Science University of New Mexico

Checking whether a given formula is an invariant at a given program location(especially,inside a loop) can be quite nontrivial even for simple loop programs,given that it is in general an undecidable *** is especially the case if the given formula is not an inductive loop invariant,as most automated techniques can only check or generate inductive loop *** this paper,conditions are identified on simple loops and formulas when this check can be performed automatically.A general theorem is proved which gives a necessary and sufficient condition for a formula to be an invariant under certain restrictions on a *** a byproduct of this analysis,a new kind of loop invariant inside the loop body,called inside-loop invariant,is *** an invariant is more general than an inductive loop invariant typically used in the Floyd-Hoare axiomatic approach to program *** use of such invariants for program debugging is explored;it is shown that such invariants can be more useful than traditional inductive loop invariants especially when one is interested in checking extreme/side conditions such as underflow,accessing array/collection data structures outside the range,divide by zero,etc.

关键词： Assertion Floyd-Hoare logic invariant invariant generation.

Revisiting the Epoch of Cosmic Acceleration

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Research in Astronomy and Astrophysics 2023年第9期23卷 1-11页

作者： David Dahiya deepak Jain Technische Universität Dresden D-01069 DresdenGermany Deen Dayal Upadhyaya College University of DelhiDwarkaNew DelhiIndia

We revisit the epoch of cosmic speed-up characterized by the redshift of transition from a decelerated to an accelerated *** redshift is termed the transition redshift(z_(t)).We use the spatially flat and non-flat variants of the most commonΛCDM and XCDM models to put constraints on the transition redshift along with the other model *** data for this analysis come from the recent and updated Pantheon+supernova(SN)data set and the Hubble parameter measurements obtained from Cosmic *** consider both data sets with their respective covariance matrices incorporating all statistical and systematic *** observe that using the combined data sets of H(z)and SNe,the best fit value of transition redshift lies in the range 0.61

关键词： (cosmology )dark energy-(cosmology )cosmological parameters-cosmology observations