23 results
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2. Munitions Propellants Residue Deposition Rates On Military Training Ranges.
- Author
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Walsh, Michael R., Walsh, Marianne E., Ampleman, Guy, Thiboutot, Sonia, Brochu, Sylvie, and Jenkins, Thomas F.
- Abstract
Training with live munitions is an integral component of preparing the modern military for warfare. Energetic compounds, such as propellants and explosives, are consumed during the use of these munitions. These compounds are never fully consumed, however, and the deposition and accumulation of energetic residue on training ranges is the result. This paper summarizes 10 years of research into propellant deposition rates for common military munitions used in the USA and Canada. Research indicates that the firing of howitzers and tanks leave very little residue, the firing of mortars can result in moderate deposition of propellant residue, small-arms firing positions have the potential for significant residue accumulation, and training with shoulder-fired rockets and 40 mm machine guns can result in dangerous quantities of unburned propellants. Residue rates vary widely for the weapon systems tested, from 10
−6 % for large rocket systems to over 70 % for shoulder-fired rockets. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
3. Research on deposition rate of TiZrV/Pd film by DC magnetron sputtering method
- Author
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Wang, Jie, Zhang, Bo, Xu, Yan-Hui, and Wang, Yong
- Published
- 2017
- Full Text
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4. Millennial-scale erosion rates in three inland drainage basins and their controlling factors since the Last Deglaciation, arid China
- Author
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Li, Yu, Wang, Nai'ang, Morrill, Carrie, Anderson, David M., Li, Zhuolun, Zhang, Chengqi, and Zhou, Xuehua
- Subjects
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EROSION , *WATERSHEDS , *GLACIATION , *ARID regions , *PETROLOGY , *HOLOCENE Epoch , *RADIOCARBON dating - Abstract
Abstract: In the regions surrounding the Qinghai Tibet Plateau, changes in erosion rates have been linked to the tectonics, climate and topography over different time scales. To understand the mechanisms governing the changes of erosion rates, it is important to study erosion rates by different methods and for different time scales. In inland drainage basins, deposition rates of terminal lake sediments can indicate basin-wide erosion rates at the millennial-scale. This paper presents three lake records of the Last Deglaciation and Holocene (Huahai Lake, Zhuye Lake and Yanchi Lake) from the Hexi Corridor, north of the Qilian Mountains, in arid China. Organic matter, terrestrial pollen concentrates, seeds, grasses and plant debris are used for conventional and AMS 14C dating. On the basis of 66 radiocarbon dates, lithology and grain-size, we infer relatively high basin-wide erosion rates during the Last Deglaciation and early Holocene in the three drainage basins, when the three lake sediments were seriously affected by reworking. The deposition rates were an order of magnitude or greater in these lakes during the Last Deglaciation and early Holocene than during the mid-to-late Holocene. During the transition period of the last glacial–interglacial cycle, significant climatic changes occurred in East and Central Asia, corresponding to the strengthening of the Asian summer monsoon and to increasing effective moisture in arid Central Asia, which can have strong impacts on basin-wide erosion rates north of the Qinghai Tibet Plateau. Moreover, melting glaciers in the Qilian Mountains probably also contributed to the high basin-wide erosion rates. At the same time, tectonic activity was not recognizable in the study area during that period. In the arid and semiarid regions surrounding the Qinghai Tibet Plateau, dramatic changes in erosion rates appear during the transition periods of the glacial–interglacial cycles, which illustrate the climatic controls on erosion rates at this time scale. [Copyright &y& Elsevier]
- Published
- 2012
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- View/download PDF
5. Throughput optimized a-Si/μc-Si tandem solar cells on sputter-etched ZnO substrates
- Author
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Klein, Stefan, Rohde, Martin, Buschbaum, Susanne, and Severin, Daniel
- Subjects
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SILICON solar cells , *SILICON crystals , *ZINC oxide , *MAGNETRON sputtering , *THIN films , *ENERGY conversion , *ECONOMIC efficiency , *SURFACE coatings - Abstract
Abstract: Recently, Applied Materials has demonstrated the ability to manufacture large area a-Si/μc-Si thin film modules with total area efficiencies of 10% and above. Reducing the production costs is now the key objective for an economic success of this technology. Decreasing the absorber layer thickness or increasing the deposition rate can reduce the cost significantly because the PECVD deposition of the silicon layers is one of the main cost contributors. But this would also reduce the conversion efficiency of amorphous/microcrystalline tandem cells (a-Si/μc-Si TJ cells). Therefore, optimizing TJ cells for maximal productivity requires a careful balancing of layer thicknesses and deposition rates. In this paper we studied the impact of deposition rates and absorber layer thicknesses for top and bottom cells. The reduction of the bottom cell (BC) thickness from 2μm to less than 1μm showed only a small impact on the stabilized module efficiency while having a big impact on the productivity of a production line. The influence of the top cell (TC) deposition rate on the other hand results in a big decrease of the efficiency while having only a small impact on the line output. 10.2% stable mini-module efficiency could be achieved with 900nm BC thickness, reducing the deposition time by 50%. [Copyright &y& Elsevier]
- Published
- 2012
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- View/download PDF
6. Assessment of sediment deposition rates in a karst depression of a small catchment in Huanjiang, Guangxi, southwest China, using the cesium-137 technique.
- Author
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Li, H., Zhang, X., Wang, K., and Wen, A.
- Subjects
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SEDIMENTATION & deposition research , *KARST , *WATERSHEDS , *CESIUM & the environment , *SOIL erosion , *DESERTIFICATION - Abstract
Use of the fallout radionuclide cesium-137 (137Cs) as a tracer has been widely employed for assessment of soil losses and dating of deposited sediment; however, few studies have been conducted in karst environments using this technique. In this study, the 137Cs technique was employed to assess sediment deposition rates in a depression in a small catchment of southwest China. Information derived from the 137Cs measurement of sediment samples collected from a depression in a small catchment in southwest China was used to estimate the sediment deposition rate since 1963, and the rate of soil erosion in the study catchment was also discussed. The results presented in this paper indicated that the depression acted as a sink of soils being eroded from the upland slopes. The mean sediment deposition rate and specific sediment yield of the study depression since 1963 were estimated to be 0.37 cm y-1 (0.15 in yr-1) and 50.2 t km-2 y-1 (0.184 tn ac-1 yr-1), respectively. Analysis of the topographic characteristics of the catchment revealed that the rate of soil redistribution of the catchment was very close to the sediment deposition rate of the depression because no significant sediment accumulation occurred upstream of the depression and in the meantime, very few sediments drained out through the sinkhole with the runoff. Therefore, it was inferred that the rate of soil redistribution in the study area was 55.8 t km-2 y-1 (0.205 tn ac-1 yr-1). Overall, the results revealed that there was a low background rate of soil loss in the karst mountain area suffering from severe land desertification in Southwest China. Furthermore, the results illuminated the potential for use of the 137Cs technique to evaluate the sediment deposition and soil erosion rates in karst areas of southwest China, where limited information regarding soil erosion and sedimentation exists. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
7. Multiwalled carbon nanotube deposition profiles within a CVD reactor: An experimental study
- Author
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Kunadian, Illayathambi, Andrews, Rodney, Pinar Mengüç, M., and Qian, Dali
- Subjects
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CARBON nanotubes , *CHEMICAL vapor deposition , *CHEMICAL reactors , *TEMPERATURE effect , *GAS flow , *CRYSTAL growth - Abstract
Abstract: A number of proposed applications of carbon nanotube (CNT) arrays require that uniform deposition of well-aligned CNTs is achieved. The CNT deposition profiles inside a chemical vapor deposition (CVD) reactor are strongly dependant on the reaction temperatures, feed gas flow rates, carrier gas flow rates and reactor geometry. In addition, objects placed in the path of the flow of feed material could affect the deposition patterns. In this paper, an experimental study aimed at achieving better control of the deposition patterns of CNTs is presented. Multiwalled CNTs were grown on a long substrate by the catalytic CVD of a xylene/ferrocene solution. The deposition patterns on the substrate were examined for different furnace temperatures, xylene/ferrocene feed rates and carrier gas flow rates. Small objects representative of electronic devices were placed at different locations on the substrate and their effect on the deposition patterns was explored. The effect of changing the height and the gap distance between these objects was also studied. [Copyright &y& Elsevier]
- Published
- 2009
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8. Simultaneous particle and vapor deposition in a laminar boundary layer
- Author
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Filippov, A.V.
- Subjects
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VAPOR-plating , *HEAT exchangers , *POWER plants - Abstract
A number of industrial and technical applications involve simultaneous particle and vapor deposition from a hot gas onto cold surfaces. For example, deposition of particles and corrosive vapors reduces the lifetime of heat exchangers in power plants and in blades of gas turbines. On another hand, in the OVD (outside vapor deposition) process used in manufacturing optical fibers, a controlled deposition of silica particles and dopant vapors is necessary for obtaining products with prescribed characteristics. In the present paper, a detailed mathematical and numerical model of this process is developed for the flow region near a stagnation point of a two-dimensional body, such as a cylinder. Using an inverse scavenging factor as a small parameter, an analytical asymptotic solution is found for vapor distribution in a condensation layer adjacent to the surface. The results of numerical calculations are presented in the form of surface temperature dependencies of dimensionless deposition rates and profiles of physical parameters of the system at a wide range of surface/gas temperature ratios. [Copyright &y& Elsevier]
- Published
- 2003
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9. Investigating spatial patterns of overbank sedimentation on river floodplains
- Author
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Walling, D. E. and He, Q.
- Published
- 1997
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10. Indoor particle dynamics in a school office: determination of particle concentrations, deposition rates and penetration factors under naturally ventilated conditions.
- Author
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Cong, X. C., Zhao, J. J., Jing, Z., Wang, Q. G., and Ni, P. F.
- Subjects
AIR pollution ,RADIOACTIVE aerosols ,AEROSOLS ,POLLUTION ,AIR quality - Abstract
Recently, the problem of indoor particulate matter pollution has received much attention. An increasing number of epidemiological studies show that the concentration of atmospheric particulate matter has a significant effect on human health, even at very low concentrations. Most of these investigations have relied upon outdoor particle concentrations as surrogates of human exposures. However, considering that the concentration distribution of the indoor particulate matter is largely dependent on the extent to which these particles penetrate the building and on the degree of suspension in the indoor air, human exposures to particles of outdoor origin may not be equal to outdoor particle concentration levels. Therefore, it is critical to understand the relationship between the particle concentrations found outdoors and those found in indoor micro-environments. In this study, experiments were conducted using a naturally ventilated office located in Qingdao, China. The indoor and outdoor particle concentrations were measured at the same time using an optical counter with four size ranges. The particle size distribution ranged from 0.3 to 2.5 μm, and the experimental period was from April to September, 2016. Based on the experimental data, the dynamic and mass balance model based on time was used to estimate the penetration rate and deposition rate at air exchange rates of 0.03-0.25 h
−1 . The values of the penetration rate and deposition velocity of indoor particles were determined to range from 0.45 to 0.82 h−1 and 1.71 to 2.82 m/h, respectively. In addition, the particulate pollution exposure in the indoor environment was analyzed to estimate the exposure hazard from indoor particulate matter pollution, which is important for human exposure to particles and associated health effects. The conclusions from this study can serve to provide a better understanding the dynamics and behaviors of airborne particle entering into buildings. And they will also highlight effective methods to reduce exposure to particles in office buildings. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
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11. Synthesis of Nanocomposite TiSiCN Coatings by Titanium Evaporation and Organosilicon Compound Activation in Hollow Cathode Arc Discharge
- Author
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Andrey Menshakov, Yulia Bruhanova, Andrey Kukharenko, and Ivan Zhidkov
- Subjects
DEPOSITION RATES ,PECVD ,GASES MIXTURE ,HEXAMETHYLDISILAZANE ,Filtration and Separation ,TITANIUM CARBIDE ,SILICON COMPOUNDS ,TITANIUM NITRIDE ,NANO-COMPOSITE COATING ,TiSiCN ,nanocomposite coatings ,PVD ,hollow cathode arc ,anodic evaporation ,Chemical Engineering (miscellaneous) ,CATHODES ,X RAY PHOTOELECTRON SPECTROSCOPY ,HOLLOW CATHODES ,ORGANOSILICON COMPOUNDS ,COATINGS ,VAPOR FLOWS ,ANODIC EVAPORATION ,Process Chemistry and Technology ,TISICN ,GAS MIXTURES ,PHYSICAL VAPOR DEPOSITION ,NANOCOMPOSITES ,ARC DISCHARGE ,HOLLOW CATHODE ARC ,EVAPORATION ,TITANIA ,NANOCOMPOSITE COATINGS - Abstract
TiSiCN coatings have been obtained by anode evaporation of titanium and the decomposi-tion of hexamethyldisilazane in an arc discharge, using a self-heated hollow cathode, at the pressure rate of 1 mTorr of the Ar+N2 gas mixture. The proposed method makes it possible to independently and widely change the amount of metal and precursor vapor flows, the pressure and composition of the vapor-gas mixture and the degree of ionic interaction on the surface of the growing coating within a single discharge system. The paper presents the method and the results of the effect of a current discharge (10–50 A), and the flux of precursor vapours (0–1 g/h), on deposition rates, compositions, and properties of TiSiCN coatings deposited by an advanced combined PVD+PECVD method. Dense homogeneous TiSiCN coatings up to 6 µm thick and up to 27.5 GPa in hardness were obtained at 7.5 µm/h. The composition of the obtained coatings has been studied by X-ray diffraction and X-ray photoelectron spectroscopy, and it has been shown that the presented methods can form nanocomposite coatings with nanocrystallites TiC, TiN, and TiCxN1−x 3–10 nm in the amorphous matrix based on SiCN. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. Russian Science Foundation, RSF: 20-79-10059 Funding: This research was funded by Russian Science Fund, grant number 20-79-10059.
- Published
- 2022
- Full Text
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12. On the Deposition Rates of Magnetron Sputtered Thin Films at Oblique Angles.
- Author
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Alvarez, Rafael, Garcia‐Martin, Jose M., Lopez‐Santos, Maria C., Rico, Victor, Ferrer, Francisco J., Cotrino, Jose, Gonzalez‐Elipe, Agustin R., and Palmero, Alberto
- Subjects
MAGNETRONS ,SPUTTERING (Physics) ,SEDIMENTATION & deposition research ,THIN film research ,GASES - Abstract
We describe here the deposition of thin films using magnetron sputtering at oblique angles. General relations between the deposition rates of the films and experimental parameters, such as gas pressure or substrate tilt angles, are deduced and experimentally tested. The model also permits the direct determination of the thermalization mean free path of the sputtered particles in the plasma gas, a key parameter defining the balance between ballistic and diffusive flows in the deposition reactor. The good agreement between experimental and calculated results supports the validity of our description, which becomes a useful tool to explain the main features of the magnetron sputtering deposition of thin films at oblique angles. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
13. Deposition rates in growing tissue: Implications for physiology, molecular biology, and response to environmental variation.
- Author
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Silk, Wendy and Bogeat-Triboulot, Marie-Béatrice
- Subjects
SEDIMENTATION & deposition ,MOLECULAR biology ,CLIMATE change ,BIOSYNTHESIS ,SOIL mineralogy ,EMPIRICAL research - Abstract
Background: Net rates of biosynthesis and mineral deposition are needed to understand the physiology and molecular biology of growth and plant responses to environmental variation. Many popular models ignore cell expansion and displacement. In contrast, the continuity equation, used with empirical data on growth velocity and concentration, allows computation of biosynthesis and deposition rates in growing tissue. Scope: This article describes data and methods needed to calculate deposition rates and reviews some insights into environmental physiology and molecular biology. Conclusions: Growth zones actively and strongly deposit mineral elements, even though local concentrations may not be changing in time. Deposition rate profiles give important insight into the mechanism of plant responses to drought and salinity, and they clarify many aspects of nitrogen metabolism in roots and leaves. This approach is also essential to understand molecular regulation of growth. A pioneering study determined transcript densities and calculated rates of change in gene expression; this study revealed how Actin 11 is highly regulated by a balance of transcription and decay during growth of roots. New technologies ( in planta cytometry, coupled with powerful computational routines and real-time confocal microscopy) will allow determination of deposition rates in growing organs and advancement in understanding of gene regulation. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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14. Sediment bioavailable organic matter, deposition rates and mixing intensity in the Setúbal–Lisbon canyon and adjacent slope (Western Iberian Margin)
- Author
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García, R., Thomsen, L., de Stigter, H.C., Epping, E., Soetaert, K., Koning, E., and de Jesus Mendes, P.A.
- Subjects
- *
OCEANIC mixing , *SEDIMENTATION & deposition , *BIOAVAILABILITY , *ORGANIC compounds , *MARINE sediment quality , *SEDIMENT transport , *OCEAN bottom , *BIODEGRADATION - Abstract
Abstract: The role of the Setúbal–Lisbon canyon in accumulation and transport of labile organic matter from the coastal sea and ocean surface water towards the deep sea was assessed by investigating the distribution of organic matter of different quality in sedimentary aggregates and surface sediments of the canyon and adjacent slopes. Total hydrolysable amino acids (THAA) and organic carbon (Corg) were measured from aggregates, and contents of Corg, chlorophyll a (chl a), phaeopigments (phaeo), chloroplastic pigment equivalents (CPE) from sediments. As indices of organic matter (OM) quality THAA:Corg, degradation index (DI), chl a:phaeo, chl a:Corg and C:N ratio were determined. Sediment profiles of chl a and the isotope 210 of lead (210Pb) were used as tracers in a transport model to estimate deposition rates and background levels of the tracers, and sediment mixing rates (Db). Whereas bulk Corg contents of canyon and slope sediments were practically similar at all depths, higher contents of THAA, chl a and CPE, as well as higher THAA:Corg, DI and chl a:Corg, in aggregates and sediments from the upper reaches of the canyon indicate that labile organic matter accumulates in the upper canyon. This is confirmed by higher chl a and 210Pb deposition and Db calculated from the model. Hence, the Setúbal–Lisbon canyon, specially the upper region, acts as a natural trap of organic matter that is transported to the region via lateral transport and vertical settling from primary productivity. Organic matter might be further transported in downward canyon direction via rebound processes. The chl a and 210Pb profiles reveal active sediment mixing by physical processes and/or animal reworking. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
15. Plasma homo- and copolymerizations of tetrafluoroethylene and chlorotrifluoroethylene.
- Author
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Golub, Morton, Wydeven, Theodore, and Finney, Lorie
- Abstract
The plasma homo- and copolymerizations of tetrafluoroethylene (TFE) and chlorotrifluoroethylene (CTFE) in a capacitively coupled tubular reactor (TR) with external electrodes were studied by means of microgravimetry and FT-IR and XPS analyses. The deposition rates for CTFE/TFE plasma copolymers, as well as the ratios of IR absorbances at 1180 and 1225 cm, and the XPS-derived Cl/C and F/C ratios, varied regularly with mol % CTFE in the feed, all of which results were dependent upon the rf power at which the plasma copolymerizations were conducted. The deposition rates for the plasma homopolymers of TFE (PPTFE) and CTFE (PPTCFE) depended markedly on rf power ( W) and monomer molar flow rate ( F). The F/C ratio for PPTFE was nearly independent of the composite parameter, W/FM (where M is the monomer molecular weight), while for PPCTFE, the F/C ratio decreased significantly and the Cl/C ratio increased slightly with increase in W/FM. The percentage of carbon as CF was 20-24% in PPTFE and 7-14% in PPCTFE. Plots of deposition rate versus W/FM for PPTFE and PPCTFE obtained in a TR differed considerably from corresponding plots in the literature for the same homopolymers prepared in a glass-cross or bell-jar reactor. [ABSTRACT FROM AUTHOR]
- Published
- 1996
- Full Text
- View/download PDF
16. Factors controlling present-day tufa dynamics in the Monasterio de Piedra Natural Park (Iberian Range, Spain): depositional environmental settings, sedimentation rates and hydrochemistry
- Author
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Vázquez-Urbez, M., Arenas, C., Sancho, C., Osácar, C., Auqué, L., and Pardo, G.
- Published
- 2010
- Full Text
- View/download PDF
17. Radiofrequency Plasma Polymers Containing Ionic Phosphonate Groups: Effect of Monomer Structure and Carrier Gas on Properties and Deposition Rate
- Author
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Danilich, Michael J. and Marchant, Roger E.
- Published
- 2002
- Full Text
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18. Relative Rates for Plasma Homo- and Copolymerizations of a Homologous Series of Fluorinated Ethylenes
- Author
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Golub, Morton A. and Wydeven, Theodore
- Published
- 1998
- Full Text
- View/download PDF
19. Mercury distribution in sediment profiles from lakes of the high pantanal, Mato Grosso State, Brazil
- Author
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De Lacerda, L. D., Salomons, W., Pfeiffer, W. C., and Bastos, W. R.
- Published
- 1991
- Full Text
- View/download PDF
20. Controlled Self-Assembly of Nanocrystalline Arrays Studied by 3D Kinetic Monte Carlo Modeling
- Author
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Abuhanif K. Bhuiyan, Steven K. Dew, and Maria Stepanova
- Subjects
Morphology ,Sensing applications ,Theoretical study ,Materials science ,Fabrication ,Metallic islands ,Nanotechnology ,Substrate (electronics) ,Controlled self-assembly ,Models ,Process condition ,Deposition rates ,Deposition (phase transition) ,Kinetic Monte Carlo ,Physical and Theoretical Chemistry ,Wetting conditions ,Nanocrystallines ,Kinetic Monte Carlo modeling ,Self-assembled arrays ,Monte Carlo methods ,Nanocrystalline material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,Nanolithography ,Self assembly process ,Physical vapor deposition ,Crystalline substrates ,Wetting ,Three dimensional computer graphics - Abstract
Fabrication of self-assembled arrays of nanocrystals (NCs) by physical vapor deposition (PVD) is a promising technique rated highly for its potential for various electronic, photonic, and sensing applications. However, the self-assembly process is not straightforward to control and direct in a desired way. A detailed understanding of how to control the size, shape, and density of self-assembled NCs by varying the accessible PVD process conditions, such as deposition rate, duration, or temperature, is critical for the potential of self-assembled nanofabrication to be fully realized. In this paper, we report a systematic kinetic Monte Carlo modeling that explicitly represents PVD synthesis of self-assembled metallic NCs on a crystalline substrate. We investigate how varying the duration of deposition, deposition rate, temperature, and substrate wetting conditions may affect the morphologies of arrays of self-assembled metallic islands and compare our results with previously reported experimentally observed surface morphologies generated by PVD and theoretical studies. © 2011 American Chemical Society.
- Published
- 2011
21. Elaboration of nitride thin films by reactive sputtering
- Author
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Arnaud Tricoteaux, Nicolas Horny, Pierre Yves Jouan, Laboratoire des Matériaux Céramiques et Procédés Associés - EA 2443 (LMCPA), and Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)
- Subjects
Materials science ,DC reactive magnetron sputtering ,taxas de deposição ,02 engineering and technology ,Substrate (electronics) ,Nitride ,01 natural sciences ,chemistry.chemical_compound ,Geochemistry and Petrology ,Sputtering ,nitreto de alumínio ,0103 physical sciences ,aluminium nitride ,General Materials Science ,vaporização em ambiente magnetron reativo DC ,Texture (crystalline) ,Thin film ,Composite material ,Waste Management and Disposal ,010302 applied physics ,Aluminium nitride ,Geology ,Biasing ,deposition rates ,021001 nanoscience & nanotechnology ,Amorphous solid ,chemistry ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Economic Geology ,0210 nano-technology - Abstract
International audience; The aim of this paper is first a better understanding of DC reactive magnetron sputtering and its implications, such as the hysteresis effect and the process instability. In a second part, this article is devoted to an example of specific application: Aluminium Nitride. AlN thin films have been deposited by reactive triode sputtering. We have studied the effect of the nitrogen contents in the discharge and the RF bias voltage on the growth of AlN films on Si(100) deposited by triode sputtering. Stoichiometry and crystal orientation of AlN films have been characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction and secondary electron microscopy. Dense and transparent AlN layers were obtained at high deposition rates. These films have a (002) orientation whatever the nitrogen content in the discharge, but the best crystallised ones are obtained at low value (10%). A linear relationship was observed between the AlN lattice parameter "c" (perpendicular to the substrate surface) and the in-plane compressive stress. Applying an RF bias to the substrate leads to a (100) texture, and films become amorphous. Moreover, the film's compressive stress increases up to a value of 8GPa before decreasing slowly as the bias voltage increases.; O objetivo desse artigo, em um primeiro momento, é uma melhor compreensão da vaporização em um ambiente magnetron reativo DC e as suas conseqüências, tais como o efeito da histeresis e o processo de instabilidade. A segunda parte desse trabalho está dedicada a um estudo de caso: o nitreto de alumínio. Filmes finos de nitreto de alumínio foram depositados por vaporização triodo reativa. Estudamos o efeito dos teores de nitrogênio, na descarga, e da voltagem RF(bias), no crescimento dos filmes de AlN em Si(100) depositados por vaporização triodo. A estequiometria e a orientação cristalina dos filmes de AlN foram caracterizadas por espectroscopia infravermelha em transformada de Fourier, difração de raios X e microscopia de elétrons secundários. Camadas densas e transparentes de AlN foram obtidas em altas taxas de deposição. Independentemente do conteúdo em nitrogênio na descarga, os filmes têm uma orientação (002), mas, para um teor de 10%, obteve-se a melhor cristalização.Uma relação linear foi observada entre o parâmetro de rede c (perpendicular à superfície do substrato) do AlN e as tensões compressivas planas.A aplicação de um "bias" RF ao substrato leva a uma textura (100) e os filmes tornam-se amorfos. Além disso, a tensão compressiva aumenta atingindo valores de até 8Gpa antes de diminuírem lentamente na medida em que o "bias" aumenta.
- Published
- 2006
22. Effects of land use and climate changes on small reservoir siltation in the agricultural belt of European Russia
- Author
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Belyaev, Vladimir, Golosov, Valentin, Markelov, Maxim, Ivanova, Nadezda, Shamshurina, Eugenia, Evrard, O., Lomonosov Moscow State University (MSU), Kazan (Volga region) Federal University, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochimie Des Impacts (GEDI), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
European Russia ,soil erosion ,siltation ,climate changes ,[SDE.MCG]Environmental Sciences/Global Changes ,microstratigraphy ,deposition rates ,small reservoirs ,[SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study ,sediment delivery ,agricultural land ,137Cs depth distribution ,[SDE]Environmental Sciences ,[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology ,[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment - Abstract
International audience; Small reservoirs of agriculture-dominated areas experience severely increased sediment input caused by soil erosion on cultivated slopes, also accompanied at some locations by gully erosion. This causes rapid decrease of the reservoir water storage and shortened periods of functioning. In this paper we discuss several examples of the 137Cs-based short-term siltation chronology of small reservoirs located in different landscape zones within the agricultural belt of European Russia. From two to four time marks could have been established in 137Cs depth distribution curves constructed from detailed depth-incremental sampling of reservoir infill sediment, allowing reconstruction of sediment microstratigraphy and deposition rates. In combination with other independent information sources this provides insight on the relative importance of recent land use changes and climatic variability in controlling sediment delivery within small agriculture-dominated fluvial systems. In combination with sediment redistribution studies, it has become possible to construct closed sediment budgets for catchments of several reservoirs and make a quantitative assessment of sediment delivery variability. Such information is important for appropriate design and management of small agricultural reservoirs in Russia.
- Published
- 2013
23. Effects of land use and climate changes on small reservoir siltation in the agricultural belt of European Russia
- Author
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Belyaev V., Golosov V., Markelov M., Ivanova N., Shamshurina E., and Evrard O.
- Subjects
European Russia ,Climate changes ,Siltation ,Agricultural land ,Deposition rates ,Small reservoirs ,Soil erosion ,Microstratigraphy ,Sediment delivery - Abstract
Small reservoirs of agriculture-dominated areas experience severely increased sediment input caused by soil erosion on cultivated slopes, also accompanied at some locations by gully erosion. This causes rapid decrease of the reservoir water storage and shortened periods of functioning. In this paper we discuss several examples of the 137Cs-based short-term siltation chronology of small reservoirs located in different landscape zones within the agricultural belt of European Russia. From two to four time marks could have been established in 137Cs depth distribution curves constructed from detailed depth-incremental sampling of reservoir infill sediment, allowing reconstruction of sediment microstratigraphy and deposition rates. In combination with other independent information sources this provides insight on the relative importance of recent land use changes and climatic variability in controlling sediment delivery within small agriculture-dominated fluvial systems. In combination with sediment redistribution studies, it has become possible to construct closed sediment budgets for catchments of several reservoirs and make a quantitative assessment of sediment delivery variability. Such information is important for appropriate design and management of small agricultural reservoirs in Russia. Copyright © 2013 IAHS Press.
- Published
- 2013
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