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Flat Absorber Phosphorous Black Nickel Coatings for Space Applications

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Journal of Materials Science & Technology 2012年第2期28卷 118-124页

作者： V.Maria Shalini P.Arockiasamy R.Uma Rani a.k.sharma Thermal Systems Group ISRO Satellite CentreVimanapura PostBangalore-560 017India

A new process of flat absorber black nickel alloy coating tion from a bath containing nickel, zinc and ammonium was developed on stainless steel by electrodeposi- sulphates; thiocyanate and sodium hypophosphite for space applications. Coating process was optimized by investigating the effects of plating parameters, viz concentration of bath constituents, current density, temperature, pH and plating time on the optical properties of the black deposits. Energy dispersive X-ray spectroscopy showed the inclusion of about 6% phosphorous in the coating. The scanning electron microscopy studies revealed the amorphous nature of the coating. The corrosion resistance of the coatings was evaluated by the electrochemical impedance spectroscopy （EIS） and linear polarization （LP） techniques. The results revealed that, phosphorous addition confers better corro- sion resistance in comparison to conventional black nickel coatings. The black nickel coating obtained from hypophosphite bath provides high solar absorptance （αs） and infrared emittance （εIR） of the order of 0.93. Environmental stability to space applications was established by the humidity and thermal cycling tests.

关键词： Phosphorous black nickel alloy Electrochemical impedance spectroscopy Linear polarization Solar absorptance Infrared emittance

A Comparative Study on the Corrosion Behaviour of Hard Anodic Coatings on AA 6061 Obtained Using DC and Pulsed DC Power Sources

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 647-656页

作者： Franco M. Hari krishna T. Anju M.Pillai A.Rajendra a.k.sharma Thermal Systems Group ISRO Satellite Centre

The corrosion behaviour of the hard anodic coatings prepared by three different methods viz., conventional hard anodizing （C-HA）, pulse hard anodizing （P-HA） and low voltage room temperature pulse hard anodizing （LVP- HA） on AA 6061 was compared using electrochemical impedance spectroscopy （EIS） and linear polarisation. Scanning electron microscope （SEM） was used to study the surface morphology before and after corrosion. EIS data revealed that no significant difference in corrosion resistance was observed among three types. Rp, Icorr and Ecorr were found to be highly stable over the exposure period up to 72 h which confirms the excellent corrosion resistance. The studies indicate that the corrosion resistance of LVP-HA and P-HA, which are processed at lower voltage and at relatively higher temperatures, are comparable to that of C-HA which is processed at sub-zero temperatures and high operating voltages. The corrosion resistance of all coatings was found to be improved after hydrothermal sealing.

关键词： Aluminium Anodic films EIS Polarisation SEM

Review of Finger millet(Eleusine coracana(L.)Gaertn):A power house of health benefiting nutrients

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Food Science and Human Wellness 2016年第3期5卷 149-155页

作者： Dinesh Chandra Satish Chandra Pallavi a.k.sharma Department of Biological Sciences Govind Ballabh Pant University of Agriculture and Technology Pantnagar263145UttarakhandIndia

The bulk of the world’s millet crop is produced by India,Nigeria,Niger,Mali,Burkina Faso,Chad,and *** millet(Eleusine coracana(L.)Gaertn),little millet(Panicum sumatrense Roth ex Roem.&Schult.),foxtail millet(Setaria italica(L.)***)and proso millet(Panicum miliaceum L.)are most commonly found species among various millet *** India,finger millet occupy the largest area under cultivation among the small *** millet stands unique among the cereals such as barley,rye and oats with higher nutritional contents and has outstanding properties as a subsistence food *** is rich in calcium(0.34%),dietary fiber(18%),phytates(0.48%),protein(6%–13%)minerals(2.5%–3.5%),and phenolics(0.3%–3%).Moreover,it is also a rich source of thiamine,riboflavin,iron,methionine,isoleucine,leucine,phenylalanine and other essential amino *** abundance of these phytochemicals enhances the nutraceutical potential of finger millet,making it a powerhouse of health benefiting *** has distinguished health beneficial properties,such as anti-diabetic(type 2 diabetes mellitus),anti-diarrheal,antiulcer,anti-inflammatory,antitumerogenic(k562 chronic myeloid leukemia),atherosclerogenic effects,antimicrobial and antioxidant properties.

关键词： power benefit occupy

Optical and Microstructural Characterisations of Pulsed rf Magnetron Sputtered Alumina Thin Film

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Journal of Materials Science & Technology 2013年第10期29卷 929-936页

作者： I.Neelakanta Reddy V.Rajagopal Reddy N.Sridhara S.Basavaraja a.k.sharma Arjun Dey Thermal Systems Group ISRO Satellite CentreVimanapura Post Department of Physics Sri Venkateswara University Bruker India Nanotechnology Laboratory Jawaharlal Nehru Centre for Advanced Scientifc Research (JNCASR)

Alumina thin films were deposited on fused quartz and SS304 substrate by pulsed rf magnetron sputtering with both direct and reactive methods. The films were characterised by energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy and atomic force microscopy to reveal the microstructure, surface morphology and topography of thin films. Transmittance and reflectance of alumina thin film were evaluated after deposition on the quartz substrate. Transmittance of the quartz remains almost un-altered when alumina was deposited by the reactive sputtering. A marginal decrease of ~4% in the transmittance of quartz was, however, observed after deposition of alumina by direct sputtering. Infrared emittance of the substrate also remains almost constant after deposition of thin alumina film. Further, as-deposited alumina on SS304 obtained by both direct and reactive sputtering process was amorphous in nature. However, after annealing crystalline peaks were observed.

关键词： Alumina Thin film rf magnetron sputtering Microstructure Transmittance Reflectance Infrared emissivity

A Constitutive Modeling and Experimental Effect of Shock Wave on the Microstructural Sub-strengthening of Granular Copper

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Journal of Metallic Material Research 2021年第1期4卷 19-25页

作者： A.D.sharma a.k.sharma N.Thakur Department of Physics Government College ChowariChamba176302India Om Sterling Global University-Hisar Haryana125001India Department of Physics Himachal Pradesh UniversityShimla171005India

Micro-sized copper powder(99.95%;O≤0.3)has been shock-processed with explosives of high detonation velocities of the order of 7.5 km/s to observe the structural and microstructural *** shock-consolidation technique has been used to obtain conglomerates of granular *** technique involves the cylindrical compaction system wherein the explosive-charge is in direct proximity with the powder whereas the other uses indirect shock pressure with die-plunger *** simulations have been performed on with Eulerian code *** simulated results show a good agreement with the experimental observation of detonation parameters like detonation velocity,pressure,particle velocity and shock pressure in the reactive media.A pin contactor method has been utilized to calculate the detonation pressure *** angled x-ray diffraction studies reveal that the crystalline structure(FCC)of the shocked specimen matches with the un-shocked *** emissive scanning electron microscopic examination of the compacted specimens show a good sub-structural strengthening and complement the theoretical *** diffraction based particle size analyzer also points towards the reduced particle size of the shock-processed specimen under high detonation ***-hardness tests conducted under variable loads of 0.1 kg,0.05 kg and 0.025 kg force with diamond indenter optical micrographs indicate a high order of micro-hardness of the order of 159 *** pycnometry used for the density measurement of the compacts shows that a compacted density of the order of 99.3%theoretical mean density has been achieved.

关键词： Shock waves Wide angle x-ray diffraction Microstructure FE-SEM Laser diffraction Microhardness

Study on the Crystal Structure and Microstructure Evolution of Shock-processed Titanium Powder

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Journal of Metallic Material Research 2019年第2期2卷 20-25页

作者： A.D.sharma a.k.sharma N.Thakur Department of Physics Government College ChowariChamba176302India Dean Research Om Sterling UniversityHisar-125001India Department of Physics Himachal Pradesh UniversityShimla171005India

Titanium powder was rapidly solidified by using shock-wave consolidation *** critical parameters were controlled by intrumented detonics and *** compacted specimens were investigated for crystal structure and microstructural strengthening by using standard diagnostic *** density of the final product was found to be greater than 96% of the theoretical value.X-ray diffraction pattern reveals intact crystalline structure without the presence of any undesired *** particle size reduction indicated by XRD was supported by laser diffraction based particle size *** from energy dispersive spectroscopy ruled out the possibility of any segregation within the *** electron microscopy showed crack-free,voids-free,melt-free,fracture-less compacts of titanium with a unidirectional dendrite orientation without any grain-growth.

关键词： Crystal structure Microstructure Shock waves Rapid solidification Titanium

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印度铁路内燃机车出口挑战

国外内燃机车 2003年第1期 39-42页

作者： a.k.sharma 王正民印度铁路研究开发和标准化组织机车

简要介绍了印度铁路迄今以来的内燃机车出口情况 ,其中包括几种典型的出口机车的主要设计特点和技术参数 ;同时还描述了对出口内燃机车的要求和未来的挑战 ,其中包括技术升级 ,降低生产成本和寿命期成本 ,对样机进行验证和试验 ,缩短设... 详细信息

简要介绍了印度铁路迄今以来的内燃机车出口情况 ,其中包括几种典型的出口机车的主要设计特点和技术参数 ;同时还描述了对出口内燃机车的要求和未来的挑战 ,其中包括技术升级 ,降低生产成本和寿命期成本 ,对样机进行验证和试验 ,缩短设计周期。

关键词：印度铁路内燃机车技术参数综述出口贸易

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谷子基因型×环境互作和稳定性的分析

园艺与种苗 1992年第5期 14-15页

作者： a.k.sharma 李爱玉王怀忠

对作物籽粒产量来说,不同环境下基因型的稳定性对任何育种计划都非常重要。基因型×环境互作越高,育种中改进的机会就越小。由Finlay等(1963)和Perkins等(1968)提出的方法来获得对互作的可靠估计。由于谷子[Seteria italica(L.)***.]是... 详细信息

对作物籽粒产量来说,不同环境下基因型的稳定性对任何育种计划都非常重要。基因型×环境互作越高,育种中改进的机会就越小。由Finlay等(1963)和Perkins等(1968)提出的方法来获得对互作的可靠估计。由于谷子[Seteria italica(L.)***.]是印度拉贾斯坦、马哈拉施特拉、奥里萨、比哈尔和安得

关键词：回归系数总平均值离差谷子小米籽粒产量生物产量基因型遗传型 SIC 主穗环境互作总体水平

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谷子基因型×环境互作和稳定性的分析

国外农学（杂粮作物） 1992年第5期 14-15页

作者： a.k.sharma 李爱玉王怀忠

对作物籽粒产量来说,不同环境下基因型的稳定性对任何育种计划都非常重要。基因型×环境互作越高,育种中改进的机会就越小。由Finlay等(1963)和Perkins等(1968)提出的方法来获得对互作的可靠估计。

关键词：谷子基因型环境稳定性