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Defence Technology（防务技术） 2018年第3期14卷 250-260页

作者： Pratim Kumar puran chandra joshi Rajiv Kumar Shelly Biswas Department of Space Engineering & Rocketry Birla Institute of Technology Department of Mechanical Engineering Vidya Vihar Institute of Technology

This paper presents the catalytic effects of Cu-Co~* catalyst on the decomposition of AN and AN/KDN based oxidizer and propellant samples. Ozawa-Flynn-Wall(OFW) iso-conversional method was used for the kinetic studies and to compute the activation energy(Ea) values for various decomposition steps of the prepared oxidizer and propellant samples in the temperature range of 50 e500C. TG-DTG experiments were carried out for both oxidizer and propellant samples at the heating rates of 3, 5, and 10C/min. AN/KDN based oxidizer samples were prepared by an evaporative co-crystallization method. Citric acid sol-gel method was used for the synthesis of Cu-Co~* catalyst. The propellant sample contains HTPB as the fuel binder along with other ingredients such as TDI, DOA, and Glycerol. The Cu-Co~* catalyst was used as 2% by weight to the total weight of catalyzed oxidizer and propellant samples. It was observed from the present study that, Cu-Co~* catalyst helps in reducing the Ea values for AN and AN based propellant samples. However, with the percentage increment of KDN in the AN crystals, Ea value ***, it was observed that Cu-Co~* catalyst stabilizes the initial partial decomposition of KDN.

关键词：催化氧化剂催化效果热分解 Cu 燃料取样 TG-DTG 催化剂

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

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Defence Technology（防务技术） 2016年第4期12卷 297-304页

作者： D. Chaitanya Kumar RAO Narendra YADAV puran chandra joshi Space Engineering and Rocketry Birla Institute of Technology Mesra Ranchi 835215 India

Nano-catalysts containing copper–cobalt oxides(Cu–Co–O) have been synthesized by the citric acid(CA) complexing method. Copper(II) nitrate and Cobalt(II) nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope(SEM), Energy Dispersive Spectroscopy(EDS) and Fourier Transform Infrared Spectroscopy(FTIR) methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, Cu Co-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of Cu Co-I nano-catalyst.

关键词： Metal oxides Nano-catalysts Solid propellant Burn rate Surface morphology Thermal analysis

Photometric studies of two W UMa type variables in the field of distant open cluster NGC 6866

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Research in Astronomy and Astrophysics 2016年第4期16卷 87-96页

作者： Yogesh chandra joshi Rukmini Jagirdar Santosh joshi Aryabhatta Research Institute of Observational Sciences Manora PeakNainital 263002India Center for Advanced Study in Astronomy Osmania UniversityHyderabad 500007India

We present photometric analysis of the two W UMa type binaries identified in the field of distant open star cluster NGC 6866. Although these systems, namely ID487 and ID494, were reported by joshi et al., a detailed study of these stars has not been carried out before. The orbital periods of these stars are found to be 0.415110±0.000001 day and 0.366709±0.000004 day, respectively. Based on the photometric and infrared colors, we find their respective spectral types to be K0 and K3. The photometric light vari- ations of both stars show the O＇Connell effect which can be explained by employing a dark spot on the secondary components. The V and I band light curves are analyzed using the Wilson-Devinney （WD） code and relations given by Gazeas which yield radii and masses for the binary components of star ID487 of R1 = 1.24 ± 0.01R,R2 = 1.11 4- 0.02Re, and M1 = 1.24 ± 0.02Me, M2 = 0.96 ±0.05Me and for star ID494 of R1 = 1.22 ± 0.02Re, R2 = 0.81 4- 0.01 Re, and M1 = 1.20 4- 0.06 Me, M2 = 0.47 4- 0.01 Me.

关键词： methods: observational -- techniques: photometric -- binaries: eclipsing -- stars: fundamen-tal parameters

Long-term photometric study of a faint W UMa binary in the direction of M31

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Research in Astronomy and Astrophysics 2017年第11期17卷 59-70页

作者： Yogesh chandra joshi Rukmini Jagirdar Aryabhatta Research Institute of Observational Sciences Manora Peak Nainital 263002 India Center for Advanced Study in Astronomy Osmania University 500007 India

We carry out a re-analysis of the photometric data in Rclc bands which were taken during the Nainital Microlensing Survey from 1998 to 2002 with the aim to detect gravitational microlensing events in the direction of M31. Here, we do photometric analysis of a faint W UMa binary CSS_JO04259.3＋410629 identified in the target field. The orbital period of this star is found to be 0.266402±0.000018 d. The photometric mass ratio, q, is found to be 0.28±0.01. The photometric light curves are investigated using the Wilson-Devinney （WD） code and absolute parameters are determined using empirical relations which provide masses and radii of the binary as M1 = 1.19±0.09M⊙, M2 = 0.33±0.02M⊙ and R1 = 1.02±0.04R⊙, R2 = 0.58±0.08Re respectively based on Rc band data. Quite similar values are found by analyzing/c band data. From the photometric light curve examination, the star is understood to be a low mass-ratio overcontact binary of A-subtype with a high fill-out factor of about 47%. The binary system is found to be located approximately at a distance of 2.64±0.03 kpc having a separation of 2.01 ±0.05 Re between the two components.

关键词： methods: observational -- techniques: photometric -- binaries: eclipsing -- stars: funda- mental parameters

Population I Cepheids and understanding star formation history of the Small Magellanic Cloud

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Research in Astronomy and Astrophysics 2016年第4期16卷 71-78页

作者： Yogesh chandra joshi Auro Prasad Mohanty Santosh joshi Aryabhatta Research Institute of Observational Sciences Manora PeakNainital 263002India National Institute of Technology Rourkela 769008India

In this paper, we study the age and spatial distributions of Cepheids in the Small Magellanic Cloud （SMC） as a function of their ages using data from the OGLE III photometric catalogue. A period - age relation derived for Classical Cepheids in the Large Magellanic Cloud （LMC） has been used to find the ages of Cepheids. The age distribution of the SMC Classical Cepheids is found to have a peak at log（Age）： 8.40 ± 0.10 which suggests that a major star formation event might have occurred in the SMC about 250 4- 50 Myr ago. It is believed that this star forming burst had been triggered by close interactions of the SMC with the LMC and/or the Milky Way. A comparison of the observed spatial distributions of the Cepheids and open star clusters has also been carried out to study the star formation scenario in the SMC.

关键词： stars: Cepheids -- star type: Pop I (classical) -- galaxies: SMC -- methods: statistical

Impacts of Bioinoculants Pseudomonas jesenii MP1 and Rhodococcus qingshengii S10107 on Chickpea (Cicer arietinum L.) Yield and Soil Nitrogen Status

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Pedosphere 2019年第3期29卷 388-399页

作者： Divya joshi Ramesh chandra Deep chandra SUYAL Saurabh KUMAR Reeta GOEL Department of Microbiology College of Basic Sciences and Humanities Govind Ballabh Pant University of Agriculture and Technology Pantnag ar-263145 Uttarakhand (India) Department of Soil Science College of Agriculture Govind Ballabh Pant University of Agriculture and Technology Pantnagar- 263145 Uttarakhand (India)

Cold-adapted bioinoculants are considered as harbingers of sustainable hill agriculture. Therefore, two previously characterized psychrotolerant diazotrophs, Pseudomonas jesenii MP1 and Rhodococcus qingshengii S10107, were evaluated for their plant growthpromoting potential for chickpea (Cicer arietinum L.) grown under natural field conditions. Comparative analysis of agronomical and biochemical crop parameters revealed the irrelevance of chemical fertilizers for chickpea production;the diazotrophs alone were sufficient to fulfil the crop's nutritional requirement. However, the integrated use of bacterial strains in combination with urea at 20 kg N ha^-1 as urea was being recommended for higher crop yield and better soil nitrogen status. Quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE)-based soil bacterial dynamics unveiled the persistence of both diazotrophs until the end of the crop maturation period without affecting the native micro-flora. Therefore, these bioinoculants can be explored as natural nitrogen resource, and an additional incentive in their bio-formulation will be a step towards agricultural sustainability.

关键词： agricultural sustainability denaturing gradient gel electrophoresis (DGGE) hill agriculture psychrotolerance N fertilizer N fixation N uptake quantitative polymerase chain reaction (qPCR)

White grubs, Holotrichia rustica and Holotrichia mucida （Coleoptera： Scarabaeidae） as pests of teak （Tectona grandis L. f.） seedlings

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Insect Science 2009年第6期16卷 519-525页

作者： Nitin Kulkarni Sanjay Paunikar Kailash chandra joshi John Rogers Tropical Forest Research Institute Jabalpur India Research Connections and Consulting P.O. Box 350 Toowong Queensland 4066 Australia

Field observations were carried out between 2002 and 2005 on bio-ecology of white grubs infesting teak （Tectona grandis Linn. f.） seedlings at Ramdongari Forest Nursery, Forest Development Corporation of Maharashtra, Nagpur in central India. The study collected the data required for an integrated pest management strategy against the white grubs. The species damaging teak seedlings were Holotrichia rustica （Burmeister） and H. mucida Gyllenhal. The beetles （adults） of both these species began to emerge just after the pre-monsoon showers and when the relative humidity had risen rapidly over several days, but before the first monsoon rains. While the adults fed and mated on naturally growing bushes of Ziziphus jujuba, Z mauritiana, Z. xylopyra, Acacia leucophloea and A. catechu immediately after the emergence from the teak beds in the nursery, the immature stages （grubs） of both species fed on roots of the teak seedling, leading to plant death. This is the first report of （i） damage caused to teak seedlings by grubs ofH. rustica and H. mucida, and （ii） of *** and Z. mauritiana being hosts for the beetles ofH. mucida and H, rustica. It is also the first detailed report on the field bio-ecology of the H. rustica and H. mucida as major pests ofteak. White grubs are among the toughest-to-manage pests of economic importance and information presented here on the pest incidence and damage ofH. rustica and H. mucida is important to researchers and nursery field managers for the management of these pests on teak.

关键词： adult emergence chafer beetles environmental factors incidence Indian scarabs insect pests Melolonthinae population density Ziziphus

On Semi-infinite Mathematical Programming Problems with Equilibrium Constraints Using Generalized Convexity

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Journal of the Operations Research Society of China 2020年第4期8卷 619-636页

作者： Bhuwan chandra joshi Shashi Kant Mishra Pankaj Kumar Centre for Interdisciplinary Mathematical Sciences Department of Science&TechnologyInstitute of ScienceBanaras Hindu UniversityVaranasi 221005India Department of Mathematics Institute of ScienceBanaras Hindu UniversityVaranasi 221005India Mahila Maha Vidyalaya Banaras Hindu UniversityVaranasi 221005India

In this paper,we consider semi-infinite mathematical programming problems with equilibrium constraints(SIMPPEC).By using the notion of convexificators,we establish sufficient optimality conditions for the *** formulate Wolfe and Mond–Weir-type dual models for the SIMPPEC under the invexity and generalized invexity *** and strong duality theorems are established to relate the SIMPPEC and two dual programs in the framework of convexificators.

关键词： Duality Convexificators Generalized invexity Constraint qualification

Incidence and management of white grub, Schizonycha ruficollis on seedlings of teak （Tectona grandis Linn, f,）

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Insect Science 2007年第5期14卷 411-418页

作者： NITIN KULKARNI KAILASH chandra PRAFULLA NARAHAR WAGH KAILASH chandra joshi RAM BHAJAN SINGH Forest Entomology Division Tropical Forest Research Institute Jabalpur (M. P.) Central Regional Station Zoological Survey of India Vijay Nagar Jabalpur (M. P.) Forest Development Corporation of Maharashtra Nagpur India

In investigation was conducted annually from 2002 to 2005 between the second week of May and the end of September on the incidence of scarab beetle, Schizonycha ruficollis （Fabricius） in a teak （Tectona grandis L.f.） nursery at Ramdongari, Nagpur, India. The immature stages, that is white grubs of the scarab beetle damaged 14%-52% of teak seedlings in the nursery beds, whereas the adult of the species, that is scarab beetles, were recorded on three new host trees （ Ziziphus xylopyra, Acacia catechu and A. leucophloea） in addition to the reported hosts such as ziziphus （Z. jujuba and Z. mauritiana）. Beetles of the S. ruficollis started emerging from the nursery beds just after the pre-monsoon showers and continued for 10-18 days. While beetle of S. ruficollis defoliated tree hosts available in the surroundings, the immature stages of the beetle caused major damage by feeding on root systerfls of teak seedlings with symptoms of wilting and mortality in forest nursery beds. The result of chemical and biological treatments for the management of grubs of S. ruficollis in nursery beds indicated phorate 10% granular at the rate of 20 g/m^2 and chlorpyriphos 20% emulsifiable concentrate at the rate of 5.0 mL/m^2 to be effective. Grubs of S. ruficollis have not been recorded previously as a major pest of teak （T. grandis）. This is also the first report on occurrence of S. ruficollis adults on tree hosts such as Z. xylopyra, A. catechu and A. leucophloea. White grubs being pests of economic importance and the toughest insects to manage, information given in this paper on incidence, pest status and management of Schizonycha ruficollis is of importance to researchers and forest nursery managers.

关键词： bioecology Coleoptera field incidence forest nursery insect pest management,insecticides Melolonthinae Scarabaeidae

Investigation of two coronal mass ejections from circular ribbon source region:Origin,Sun-Earth propagation and Geoeffectiveness

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Research in Astronomy and Astrophysics 2021年第12期21卷 531-549页

作者： M.Syed Ibrahim Wahab Uddin Bhuwan joshi Ramesh chandra Arun Kumar Awasthi aryabhatta research institute of observational sciences nainital 263002 india kodaikanal solar observatory indian institute of astrophysicskodaikanal-624103tamil naduindia udaipur solar observatory physical research laboratoryudaipur 313004india department of physics dsb campuskumaun universitynainital 263002india cas key laboratory of geospace environment department of geophysics and planetary sciencesuniversity of science and technology of chinahefei 230026china

In this article,we compare the properties of two coronal mass ejections(CMEs)that show similar source region characteristics but different evolutionary behaviors in the later *** discuss the two events in terms of their near-Sun characteristics,interplanetary evolution and *** carefully analyzed the initiation and propagation parameters of these events to establish the precise CMEinterplanetary CME(ICME)connection and their near-Earth *** first event is associated with poor geomagnetic storm disturbance index(Dst≈-20 n T)while the second event is associated with an intense geomagnetic storm of DST≈-119 n *** configuration of the sunspots in the active regions and their evolution are observed by Helioseismic and Magnetic Imager(HMI).For source region imaging,we rely on data obtained from Atmospheric Imaging Assembly(AIA)on board Solar Dynamics Observatory(SDO)and Hαfiltergrams from the Solar Tower Telescope at Aryabhatta Research Institute of Observational Sciences(ARIES).For both the CMEs,flux rope eruptions from the source region triggered flares of similar intensities(≈M1).At the solar source region of the eruptions,we observed a circular ribbon flare(CRF)for both cases,suggesting fan-spine magnetic configuration in the active region *** multi-channel SDO observations confirm that the eruptive flares and subsequent CMEs were intimately related to the filament *** the Large Angle and Spectrometric Coronograph(LASCO)field of view(FOV)the two CMEs propagated with linear speeds of 671 and 631 km s-1,*** CMEs were tracked up to the Earth by Solar Terrestrial Relations Observatory(STEREO)*** find that the source region evolution of CMEs,guided by the large-scale coronal magnetic field configuration,along with near-Sun propagation characteristics,such as CME-CME interactions,played important roles in deciding the evolution of CMEs in the interplanetary medium and subsequently their geoeffec

关键词： Sun:coronal mass ejections(CMEs) Sun:flares