WorldWideScience

Sample records for deposition process due

  1. Influence of radioactive contamination to agricultural products due to dry and wet deposition processes during a nuclear emergency

    International Nuclear Information System (INIS)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Han, Moon Hee; Choi, Yong Ho; Lee, Chang Woo

    2002-01-01

    Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than dry deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants

  2. Impact of residual by-products from tungsten film deposition on process integration due to nonuniformity of the tungsten film

    CERN Document Server

    Sidhwa, A; Gandy, T; Melosky, S; Brown, W; Ang, S; Naseem, H; Ulrich, R

    2002-01-01

    The effects of residual by products from a tungsten film deposition process and their impact on process integration due to the nonuniformity of the tungsten film were investigated in this work. The tungsten film deposition process involves three steps: nucleation, stabilization, and tungsten bulk fill. Six experiments were conducted in search for a solution to the problem. The resulting data suggest that excess nitrogen left in the chamber following the tungsten nucleation step, along with residual by products, causes a shift in the tungsten film uniformity during the tungsten bulk fill process. Data reveal that, due to the residual by products, an abnormal grain growth occurs causing a variation in the tungsten thickness across the wafer during the bulk fill step. Although several possible solutions were revealed by the experiments, potential integration problems limited the acceptable solutions to one. The solution chosen was the introduction of a 10 s pumpdown immediately following the nucleation step. Thi...

  3. Micromorphology of modern tills in southwestern Spitsbergen – insights into depositional and post-depositional processes

    Directory of Open Access Journals (Sweden)

    Skolasińska Katarzyna

    2016-12-01

    Full Text Available Textural properties and microstructures are commonly used properties in the analysis of Pleistocene and older glacial deposits. However, contemporary glacial deposits are seldom studied, particularly in the context of post-depositional changes. This paper presents the results of a micromorphological study of recently deposited tills in the marginal zones of Hansbreen and Torellbreen, glaciers in southwestern Spitsbergen. The main objectives of this study were to compare modern tills deposited in subglacial and supraglacial conditions, as well as tills that were freshly released from ice with those laid down several decades ago. The investigated tills are primarily composed of large clasts of metamorphic rocks and represent coarse-grained, matrix-supported diamictons. The tills reveal several characteristic features for ductile (e.g. turbate structures and brittle (e.g. lineations, microshears deformations, which have been considered to be indicative of subglacial conditions. In supraglacial tills, the same structures are common as in the subglacial deposits, which points to the preservation of the primary features, though the sediment was transferred up to the glacier surface due to basal ice layer deformation and redeposited as slumps, or to formation of similar structures due to short-distance sediment re-deposition by mass flows. This study revealed that it might not be possible to distinguish subglacial and supraglacial tills on the basis of micromorphology if the latter are derived from a subglacial position. The only noted difference was the presence of iron oxide cementation zones and carbonate dissolution features in supraglacial tills. These features were found in tills that were deposited at least a few years ago and are interpreted to be induced by early post-depositional processes involving porewater/sediment interactions.

  4. Powder Flux Regulation in the Laser Material Deposition Process

    Science.gov (United States)

    Arrizubieta, Jon Iñaki; Wegener, Maximiliam; Arntz, Kristian; Lamikiz, Aitzol; Ruiz, Jose Exequiel

    In the present research work a powder flux regulation system has been designed, developed and validated with the aim of improving the Laser Material Deposition (LMD) process. In this process, the amount of deposited material per substrate surface unit area depends on the real feed rate of the nozzle. Therefore, a regulation system based on a solenoid valve has been installed at the nozzle entrance in order to control the powder flux. The powder flux control has been performed based on the machine real feed rate, which is compared with the programmed feed rate. An instantaneous velocity error is calculated and the powder flow is controlled as a function of this variation using Pulse Width Modulation (PWM) signals. Thereby, in zones where the Laser Material Deposition machine reduces the feed rate due to a trajectory change, powder accumulation can be avoided and the generated clads would present a homogeneous shape.

  5. Soil Acidification due to Acid Deposition in Southern China

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Bohan

    1999-12-31

    Anthropogenic emission of SO{sub 2} and NO{sub x} to the atmosphere has made acid deposition one of the most serious environmental problems. In China, acid deposition research started in the late 1970s. The present thesis is part of a joint Chinese-Norwegian research project. The main goal of the thesis was to investigate the mechanism of soil acidification, to estimate soil responses to acid deposition, and to compare relative soil sensitivity to acidification in southern China. Laboratory experiments and modelling simulations were included. Specifically, the thesis (1) studies the characteristics of anion adsorption and cation release of the soils from southern China, (2) examines the effects of increased ionic strength in the precipitation and the effects of anion adsorption on cation release from the soils, (3) compares the relative sensitivity of these soils to acidification and the potentially harmful effects of acid deposition, (4) estimates likely soil responses to different deposition scenarios, including changes in soil waters and soil properties, and (5) investigates long-term changes in soils and soil waters in the Guiyang catchment due to acid deposition. 218 refs., 31 figs., 23 tabs.

  6. Soil Acidification due to Acid Deposition in Southern China

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Bohan

    1998-12-31

    Anthropogenic emission of SO{sub 2} and NO{sub x} to the atmosphere has made acid deposition one of the most serious environmental problems. In China, acid deposition research started in the late 1970s. The present thesis is part of a joint Chinese-Norwegian research project. The main goal of the thesis was to investigate the mechanism of soil acidification, to estimate soil responses to acid deposition, and to compare relative soil sensitivity to acidification in southern China. Laboratory experiments and modelling simulations were included. Specifically, the thesis (1) studies the characteristics of anion adsorption and cation release of the soils from southern China, (2) examines the effects of increased ionic strength in the precipitation and the effects of anion adsorption on cation release from the soils, (3) compares the relative sensitivity of these soils to acidification and the potentially harmful effects of acid deposition, (4) estimates likely soil responses to different deposition scenarios, including changes in soil waters and soil properties, and (5) investigates long-term changes in soils and soil waters in the Guiyang catchment due to acid deposition. 218 refs., 31 figs., 23 tabs.

  7. Indirect N2O emission due to atmospheric N deposition for the Netherlands

    International Nuclear Information System (INIS)

    Denier van der Gon, H.; Bleeker, A.

    2005-10-01

    Nitrous oxide (N2O) is a potent greenhouse gas produced in soils and aquatic systems. The UNFCCC requires participants to report 'indirect' N2O emissions, following from agricultural N losses to ground- and surface water and N deposition on (other) ecosystems due to agricultural sources. Indirect N2O emission due to atmospheric N deposition is presently not reported by the Netherlands. In this paper, we quantify the consequences of various tiers to estimate indirect N2O due to deposition for a country with a high agricultural N use and discuss the reliability and potential errors in the IPCC methodology. A literature review suggests that the current IPCC default emission factor for indirect N2O from N deposition is underestimated by a factor 2. Moreover, considering anthropogenic N emissions from agriculture only and not from e.g., traffic and industry, results in further underestimation of indirect N2O emissions. We calculated indirect N2O emissions due to Dutch anthropogenic N emissions to air by using official Dutch N emission data as input in an atmospheric transport and deposition model in combination with land use databases. Next, land use-specific emission factors were used to estimate the indirect N2O emission. This revealed that (1) for some countries, like the Netherlands, most agricultural N emitted will be deposited on agricultural soils, not on natural ecosystems and, (2) indirect N2O emissions are at least 20% higher because more specific emission factors can be applied that are higher than the IPCC default. The results suggest that indirect N2O emission due to deposition is underestimated in current N2O budgets

  8. Microcrystalline silicon deposition: Process stability and process control

    International Nuclear Information System (INIS)

    Donker, M.N. van den; Kilper, T.; Grunsky, D.; Rech, B.; Houben, L.; Kessels, W.M.M.; Sanden, M.C.M. van de

    2007-01-01

    Applying in situ process diagnostics, we identified several process drifts occurring in the parallel plate plasma deposition of microcrystalline silicon (μc-Si:H). These process drifts are powder formation (visible from diminishing dc-bias and changing spatial emission profile on a time scale of 10 0 s), transient SiH 4 depletion (visible from a decreasing SiH emission intensity on a time scale of 10 2 s), plasma heating (visible from an increasing substrate temperature on a time scale of 10 3 s) and a still puzzling long-term drift (visible from a decreasing SiH emission intensity on a time scale of 10 4 s). The effect of these drifts on the crystalline volume fraction in the deposited films is investigated by selected area electron diffraction and depth-profiled Raman spectroscopy. An example shows how the transient depletion and long-term drift can be prevented by suitable process control. Solar cells deposited using this process control show enhanced performance. Options for process control of plasma heating and powder formation are discussed

  9. Salt separation of uranium deposits generated from electrorefining in pyro process

    International Nuclear Information System (INIS)

    Kwon, S. W.; Park, K. M.; Jeong, J. H.; Lee, H. S.; Kim, J. G.

    2012-01-01

    Electrorefining is a key step in a pyro processing. Electrorefining process is generally composed of two recovery steps- deposit of uranium onto a solid cathode(electrorefining) and then the recovery of the remaining uranium and TRU(TransUranic) elements simultaneously by a liquid cadmium cathode(electrowinning). The uranium ingot is prepared from the deposits after the salt separation. In this study, the sequential operation of the liquid salt separation? distillation of the residual salt was attempted for the achievement of high throughput performance in the salt separation. The effects of deposit size and packing density were also investigated with steel chips, steel chips, and uranium dendrites. The apparent evaporation rate decreased with the increasing packing density or the increasing size of deposits due to the hindrance of the vapor transport by the deposits. It was found that the packing density and the geometry of deposit crucible are important design parameters for the salt separation system. Base on the results of the study, an engineering scale salt distiller was developed and installed in the argon cell. The salt distiller is a batch-type, and the process capacity to about 50 kg U-deposits/day. The design of the salt distiller is based on the remote operation by Master Slave Manipulator (MSM) and a hoist. The salt distiller is composed of two large blocks of the distillation tower and the crucible loading system for the transportation to maintenance room via the Large Transfer Lock (LTL)

  10. Salt separation of uranium deposits generated from electrorefining in pyro process

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. W.; Park, K. M.; Jeong, J. H.; Lee, H. S.; Kim, J. G. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Electrorefining is a key step in a pyro processing. Electrorefining process is generally composed of two recovery steps- deposit of uranium onto a solid cathode(electrorefining) and then the recovery of the remaining uranium and TRU(TransUranic) elements simultaneously by a liquid cadmium cathode(electrowinning). The uranium ingot is prepared from the deposits after the salt separation. In this study, the sequential operation of the liquid salt separation? distillation of the residual salt was attempted for the achievement of high throughput performance in the salt separation. The effects of deposit size and packing density were also investigated with steel chips, steel chips, and uranium dendrites. The apparent evaporation rate decreased with the increasing packing density or the increasing size of deposits due to the hindrance of the vapor transport by the deposits. It was found that the packing density and the geometry of deposit crucible are important design parameters for the salt separation system. Base on the results of the study, an engineering scale salt distiller was developed and installed in the argon cell. The salt distiller is a batch-type, and the process capacity to about 50 kg U-deposits/day. The design of the salt distiller is based on the remote operation by Master Slave Manipulator (MSM) and a hoist. The salt distiller is composed of two large blocks of the distillation tower and the crucible loading system for the transportation to maintenance room via the Large Transfer Lock (LTL)

  11. Uranium ore deposits: geology and processing implications

    International Nuclear Information System (INIS)

    Belyk, C.L.

    2010-01-01

    There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique set of geological characteristics which may also result in unique processing implications. Primary uranium production in the past decade has predominantly come from only a few of these deposit types including: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic ones. Processing implications can vary widely between and within the different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy, ore hardness, porosity, uranium mineral morphology and carbon content. Processing difficulties may occur as a result of one or more of these characteristics. In order to meet future uranium demand, it is imperative that innovative processing approaches and new technological advances be developed in order that many of the marginally economic traditional and uneconomic non-traditional uranium ore deposits can be exploited. (author)

  12. Earth Surface Processes, Landforms and Sediment Deposits

    Science.gov (United States)

    Bridge, John; Demicco, Robert

    Earth surface processes, landforms and sediment deposits are intimately related - involving erosion of rocks, generation of sediment, and transport and deposition of sediment through various Earth surface environments. These processes, and the landforms and deposits that they generate, have a fundamental bearing on engineering, environmental and public safety issues; on recovery of economic resources; and on our understanding of Earth history. This unique textbook brings together the traditional disciplines of sedimentology and geomorphology to explain Earth surface processes, landforms and sediment deposits in a comprehensive and integrated way. It is the ideal resource for a two-semester course in sedimentology, stratigraphy, geomorphology, and Earth surface processes from the intermediate undergraduate to beginning graduate level. The book is also accompanied by a website hosting illustrations and material on field and laboratory methods for measuring, describing and analyzing Earth surface processes, landforms and sediments.

  13. Atmospheric deposition of heavy metals due to dry, wet and occult deposition at the altitude profile Achenkirch

    International Nuclear Information System (INIS)

    Stopper, S.

    2001-12-01

    The goal of this work was to determine the height dependence of the three types of deposition throughout a one year time period to be able to get information about their elevational and seasonal behavior. In the time period from October 1998 to November 1999 measurements of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn in aerosol, rain and cloud water were conducted in the Achenkirch-Valley in Tyrol, Austria. Afterwards the dry and occult deposition were modeled. The estimated annual inputs of metals at the two measurement sites Christlumkopf (1758 m a.s.l.) Mueeggerkoel (940 m a.s.l.) and the limits of the national law for protection of forest are shown. The measured depositions at both sites were far below the legal regulations. Due to the much higher occult deposition ratio at the top of the mountain the total annual input at the Christlumkopf was higher than at the Mueeggerkoel. This indicates the potential importance of occult deposition. (author)

  14. Optimization of Nano-Process Deposition Parameters Based on Gravitational Search Algorithm

    Directory of Open Access Journals (Sweden)

    Norlina Mohd Sabri

    2016-06-01

    Full Text Available This research is focusing on the radio frequency (RF magnetron sputtering process, a physical vapor deposition technique which is widely used in thin film production. This process requires the optimized combination of deposition parameters in order to obtain the desirable thin film. The conventional method in the optimization of the deposition parameters had been reported to be costly and time consuming due to its trial and error nature. Thus, gravitational search algorithm (GSA technique had been proposed to solve this nano-process parameters optimization problem. In this research, the optimized parameter combination was expected to produce the desirable electrical and optical properties of the thin film. The performance of GSA in this research was compared with that of Particle Swarm Optimization (PSO, Genetic Algorithm (GA, Artificial Immune System (AIS and Ant Colony Optimization (ACO. Based on the overall results, the GSA optimized parameter combination had generated the best electrical and an acceptable optical properties of thin film compared to the others. This computational experiment is expected to overcome the problem of having to conduct repetitive laboratory experiments in obtaining the most optimized parameter combination. Based on this initial experiment, the adaptation of GSA into this problem could offer a more efficient and productive way of depositing quality thin film in the fabrication process.

  15. Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

    Directory of Open Access Journals (Sweden)

    Fang Luo

    2015-03-01

    Full Text Available Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

  16. A new thin film deposition process by cathodic plasma electrolysis

    International Nuclear Information System (INIS)

    Paulmier, T.; Kiriakos, E.; Bell, J.; Fredericks, P.

    2004-01-01

    Full text: A new technique, called atmospheric pressure plasma deposition (APPD), has been developed since a few years for the deposition of carbon and DLC, Titanium or Silicon films on metal and metal alloys substrates. A high voltage (2kV) is applied in a liquid electrolytic solution between an anode and a cathode, both electrodes being cylindrical: a glow discharge is then produced and confined at the vicinity of the cathode. The physic of the plasma in the electrolytic solution near the cathode is very different form the other techniques of plasma deposition since the pressure is here close to the atmospheric pressure. We describe here the different physico-chemical processes occurring during the process. In this cathodic process, the anodic area is significantly larger than the cathode area. In a first step, the electrolytic solution is heated by Joule effect induced by the high voltage between the electrodes. Due to the high current density, the vaporization of the solution occurs near the cathode: a large amount of bubbles are produced which are stabilized at the electrode by hydrodynamic and electromagnetic forces, forming a vapour sheath. The electric field and voltage drop are then concentrated in this gas envelope, inducing the ionization of the gas and the ignition of a glow discharge at the surface of the material. This plasma induces the formation of ionized and reactive species which diffuse and are accelerated toward the cathode. These excited species are the precursors for the formation of the deposition material. At the same time, the glow discharge interacts with the electrolyte solution inducing also ionization, convection and polymerization processes in the liquid: the solution is therefore a second source of the deposition material. A wide range of films have been deposited with a thickness up to 10 micrometers. These films have been analyzed by SEM and Raman spectroscopy. The electrolytic solution has been characterized by GC-MS and the

  17. Differences in Nanosecond Laser Ablation and Deposition of Tungsten, Boron, and WB2/B Composite due to Optical Properties

    Directory of Open Access Journals (Sweden)

    Tomasz Moscicki

    2016-01-01

    Full Text Available The first attempt to the deposition of WB3 films using nanosecond Nd:YAG laser demonstrated that deposited coatings are superhard. However, they have very high roughness. The deposited films consisted mainly of droplets. Therefore, in the present work, the explanation of this phenomenon is conducted. The interaction of Nd:YAG nanosecond laser pulse with tungsten, boron, and WB2/B target during ablation is investigated. The studies show the fundamental differences in ablation of those materials. The ablation of tungsten is thermal and occurs due to only evaporation. In the same conditions, during ablation of boron, the phase explosion and/or fragmentation due to recoil pressure is observed. The deposited films have a significant contribution of big debris with irregular shape. In the case of WB2/B composite, ablation is significantly different. The ablation seems to be the detonation in the liquid phase. The deposition mechanism is related mainly to the mechanical transport of the target material in the form of droplets, while the gaseous phase plays marginal role. The main origin of differences is optical properties of studied materials. A method estimating phase explosion occurrence based on material data such as critical temperature, thermal diffusivity, and optical properties is shown. Moreover, the effect of laser wavelength on the ablation process and the quality of the deposited films is discussed.

  18. Deposition behavior of colloid in filtration process through glass beads packed bed

    International Nuclear Information System (INIS)

    Chinju, Hirofumi; Nagasaki, Shinya; Tanaka, Satoru; Tanaka, Tadao; Takebe, Shinichi; Ogawa, Hiromichi

    1999-01-01

    We investigated the deposition behavior in colloid transport through porous media by conducting column experiments and batch experiments using polystyrene latex particles and spherical glass beads. The conclusion of this present work are summarized as follows: (1) The comparison between the results of the batch and the column experiments indicated that the deposition was enhanced in the column experiments compared with the batch experiments due to particles trapped by the effect of slow field. (2) Colloid BTCs showed three different stages of deposition which can be characterized by the different rate of the change in the C/C O . Three stages can be explained by the existence of large area of weak deposition sites and small area of strong deposition sites on the collector surfaces. (3) The amount of deposited particles until the beginning of the third stage was larger for lower flow velocity. (4) The results of the column experiments revealed that breakthrough behavior of colloidal particles of the second run after back wash process is affected by remaining particles on collector surfaces. (J.P.N.)

  19. Process-structure-property relationships of micron thick gadolinium oxide films deposited by reactive electron beam-physical vapor deposition (EB-PVD)

    Science.gov (United States)

    Grave, Daniel A.

    Gadolinium oxide (Gd2O3) is an attractive material for solid state neutron detection due to gadolinium's high thermal neutron capture cross section. Development of neutron detectors based on Gd2 O3 requires sufficiently thick films to ensure neutron absorption. In this dissertation work, the process-structure-property relationships of micron thick Gd2O3 films deposited by reactive electron-beam physical vapor deposition (EB-PVD) were studied. Through a systematic design of experiments, fundamental studies were conducted to determine the effects of processing conditions such as deposition temperature, oxygen flow rate, deposition rate, and substrate material on Gd2O3 film crystallographic phase, texture, morphology, grain size, density, and surface roughness. Films deposited at high rates (> 5 A/s) were examined via x-ray diffraction (XRD) and Raman spectroscopy. Quantitative phase volume calculations were performed via a Rietveld refinement technique. All films deposited at high rates were found to be fully monoclinic or mixed cubic/monoclinic phase. Generally, increased deposition temperature and increased oxygen flow resulted in increased cubic phase volume. As film thickness increased, monoclinic phase volume increased. Grazing incidence x-ray diffraction (GIXRD) depth profiling analysis showed that cubic phase was only present under large incidence angle (large penetration depth) measurements, and after a certain point, only monoclinic phase was grown. This was confirmed by transmission electron microscopy (TEM) analysis with selected area diffraction (SAD). Based on this information, a large compressive stress was hypothesized to cause the formation of the monoclinic phase and this hypothesis was confirmed by demonstrating the existence of a stress induced phase transition. An experiment was designed to introduce compressive stress into the Gd2O 3 films via ion beam assisted deposition (IBAD). This allowed for systematic increase in compressive stress while

  20. Plasma and process characterization of high power magnetron physical vapor deposition with integrated plasma equipment--feature profile model

    International Nuclear Information System (INIS)

    Zhang Da; Stout, Phillip J.; Ventzek, Peter L.G.

    2003-01-01

    High power magnetron physical vapor deposition (HPM-PVD) has recently emerged for metal deposition into deep submicron features in state of the art integrated circuit fabrication. However, the plasma characteristics and process mechanism are not well known. An integrated plasma equipment-feature profile modeling infrastructure has therefore been developed for HPM-PVD deposition, and it has been applied to simulating copper seed deposition with an Ar background gas for damascene metalization. The equipment scale model is based on the hybrid plasma equipment model [M. Grapperhaus et al., J. Appl. Phys. 83, 35 (1998); J. Lu and M. J. Kushner, ibid., 89, 878 (2001)], which couples a three-dimensional Monte Carlo sputtering module within a two-dimensional fluid model. The plasma kinetics of thermalized, athermal, and ionized metals and the contributions of these species in feature deposition are resolved. A Monte Carlo technique is used to derive the angular distribution of athermal metals. Simulations show that in typical HPM-PVD processing, Ar + is the dominant ionized species driving sputtering. Athermal metal neutrals are the dominant deposition precursors due to the operation at high target power and low pressure. The angular distribution of athermals is off axis and more focused than thermal neutrals. The athermal characteristics favor sufficient and uniform deposition on the sidewall of the feature, which is the critical area in small feature filling. In addition, athermals lead to a thick bottom coverage. An appreciable fraction (∼10%) of the metals incident to the wafer are ionized. The ionized metals also contribute to bottom deposition in the absence of sputtering. We have studied the impact of process and equipment parameters on HPM-PVD. Simulations show that target power impacts both plasma ionization and target sputtering. The Ar + ion density increases nearly linearly with target power, different from the behavior of typical ionized PVD processing. The

  1. Deference and Due Process

    OpenAIRE

    Vermeule, Cornelius Adrian

    2015-01-01

    In the textbooks, procedural due process is a strictly judicial enterprise; although substantive entitlements are created by legislative and executive action, it is for courts to decide independently what process the Constitution requires. The notion that procedural due process might be committed primarily to the discretion of the agencies themselves is almost entirely absent from the academic literature. The facts on the ground are very different. Thanks to converging strands of caselaw ...

  2. 5 CFR 732.301 - Due process.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Due process. 732.301 Section 732.301...) NATIONAL SECURITY POSITIONS Due Process and Reporting § 732.301 Due process. When an agency makes an... any determination. (b) Comply with all applicable administrative due process requirements, as provided...

  3. A discrete element based simulation framework to investigate particulate spray deposition processes

    KAUST Repository

    Mukherjee, Debanjan

    2015-06-01

    © 2015 Elsevier Inc. This work presents a computer simulation framework based on discrete element method to analyze manufacturing processes that comprise a loosely flowing stream of particles in a carrier fluid being deposited on a target surface. The individual particulate dynamics under the combined action of particle collisions, fluid-particle interactions, particle-surface contact and adhesive interactions is simulated, and aggregated to obtain global system behavior. A model for deposition which incorporates the effect of surface energy, impact velocity and particle size, is developed. The fluid-particle interaction is modeled using appropriate spray nozzle gas velocity distributions and a one-way coupling between the phases. It is found that the particle response times and the release velocity distribution of particles have a combined effect on inter-particle collisions during the flow along the spray. It is also found that resolution of the particulate collisions close to the target surface plays an important role in characterizing the trends in the deposit pattern. Analysis of the deposit pattern using metrics defined from the particle distribution on the target surface is provided to characterize the deposition efficiency, deposit size, and scatter due to collisions.

  4. Effect of heat treatment on the characteristics of tool steel deposited by the directed energy deposition process

    Science.gov (United States)

    Park, Jun Seok; Lee, Min-Gyu; Cho, Yong-Jae; Sung, Ji Hyun; Jeong, Myeong-Sik; Lee, Sang-Kon; Choi, Yong-Jin; Kim, Da Hye

    2016-01-01

    The directed energy deposition process has been mainly applied to re-work and the restoration of damaged steel. Differences in material properties between the base and the newly deposited materials are unavoidable, which may affect the mechanical properties and durability of the part. We investigated the effect of heat treatment on the characteristics of tool steel deposited by the DED process. We prepared general tool steel materials of H13 and D2 that were deposited onto heat-treated substrates of H13 and D2, respectively, using a direct metal tooling process. The hardness and microstructure of the deposited steel before and after heat treatment were investigated. The hardness of the deposited H13 steel was higher than that of wrought H13 steel substrate, while that of the deposited D2 was lower than that of wrought D2. The evolution of the microstructures by deposition and heat treatment varied depending on the materials. In particular, the microstructure of the deposited D2 steel after heat treatment consisted of fine carbides in tempered martensite and it is expected that the deposited D2 steel will have isotropic properties and high hardness after heat treatment.

  5. Influence of predictive contamination to agricultural products due to dry and wet processes during an accidental release of radionuclides

    International Nuclear Information System (INIS)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Jeong, Hyo Joon; Han, Moon Hee; Lee, Chang Woo

    2003-01-01

    The influence of predictive contamination to agricultural products due to the wet processes as well as dry processes from radioactive air concentration during a nuclear emergency is comprehensively analyzed. The previous dynamic food chain model DYNACON considering Korean agricultural and environmental conditions, in which the initial input parameter was radionuclide concentrations on the ground, is improved so as to evaluate radioactive contamination to agricultural products from either radioactive air concentrations or radionuclide concentrations on the ground. As for the results, wet deposition is a more dominant mechanism than dry deposition in contamination on the ground. While, the contamination levels of agricultural products are strongly dependent on radionuclide and precipitation when the deposition of radionuclides occurs. It means that the contamination levels of agricultural products are determined from which is the more dominant process between deposition on the ground and interception to agricultural plants

  6. The Impact of Hydrodynamics in Erosion - Deposition Process in Can Gio Mangrove Biosphere Reserve, South Viet Nam

    Science.gov (United States)

    Vo-Luong, H. P.

    2014-12-01

    Can Gio Mangrove Biosphere Reserve is always considered as a friendly green belt to protect and bring up the habitants. However, recently some mangrove areas in the Dong Tranh estuary are being eroded seriously. Based on the field measurements in SW and NE monsoons as well as data of topography changes in 10 years, it is proved that hydrodynamics of waves, tidal currents and riverine currents are the main reasons for erosion-deposition processes at the studied site. The erosion-deposition process changes due to monsoon. The analysed results show that high waves and tidal oscillation cause the increase of the erosion rate in NE monsoon. However, high sediment deposition occurs in SW monsoon due to weak waves and more alluvium from upstream. Many young mangrove trees grow up and develop in the SW monsoon. From the research, it is strongly emphasized the role of mangrove forests in soil retention and energy dissipation.

  7. Singular deposit formation in PWR due to electrokinetic phenomena - application to SG clogging

    Energy Technology Data Exchange (ETDEWEB)

    Guillodo, M.; Muller, T.; Barale, M.; Foucault, M. [AREVA NP SAS, Technical Centre (France); Clinard, M.-H.; Brun, C.; Chahma, F. [AREVA NP SAS, Chemistry and Radiochemistry Group (France); Corredera, G.; De Bouvier, O. [Electricite de France, Centre d' Expertise de I' inspection dans les domaines de la Realisation et de l' Exploitation (France)

    2009-07-01

    The deposits which cause clogging of the 'foils' of the tube support plates (TSP) in Steam Generators (SG) of PWR present two characteristics which put forward that the mechanism at the origin of their formation is different from the mechanism that drives the formation of homogeneous deposits leading to the fouling of the free spans of SG tubes. Clogging occurs near the leading edge of the TSP and the deposits appear as diaphragms localized between both TSP and SG tubing materials, while the major part of the tube/TSP interstice presents little or no significant clogging. This type of deposit seems rather comparable to the ones which were reproduced in Lab tests to explain the flow rate instabilities observed on a French unit during hot shutdown in the 90's. The deposits which cause TSP clogging are owed to a discontinuity of the streaming currents in the vicinity of a surface singularity (orifices, scratches ...) which, in very low conductivity environment, produce local potential variations and/or current loop in the metallic pipe material due to electrokinetic effects. Deposits can be built by two mechanisms which may or not coexist: (i) accumulation of particles stabilized by an electrostatic attraction due to the local variation of electrokinetic potential, and (ii) crystalline growth of magnetite produced by the oxidation of ferrous ions on the anodic branch of a current loop. Lab investigations carried out by AREVA NP Technical Centre since the end of the 90's showed that this type of deposit occurs when the redox potential is higher than a critical value, and can be gradually dissolved when the potential becomes lower than this value which depends on the 'Material - Chemistry' couple. Special emphasis will be given in this paper to the TSP clogging of SG in PWR secondary coolant dealing particularly with the potential strong effect of electrokinetic phenomena in low conductive environment and in high temperature conditions

  8. Financial compensation due to municipalities that host radioactive waste deposits

    International Nuclear Information System (INIS)

    Silva, Renata A. da; Simoes, Francisco Fernando L.; Martins, Vivian B.

    2013-01-01

    This work aims to perform calculation about the financial compensation due to municipalities where there is viability for construction of radioactive waste deposits from low and medium activity. Were used like base structure de Resolution No. 96 of August, 10, 2010, entitled 'Model of Calculation For Financial Compensation to Municipalities' where are determinate those principal characteristics by the waste and deposits, such as the half-life, activity level, type of deposits (initial, intermediate or final), costs for construction and maintenance of deposits, demography, between others. The calculation was made according to the temporally or definitive storage for solids waste like personal protection equipment (gloves, shoes, masks, etc) resins and filters used in wastewater treatment, between others, from of nuclear and radioactivity facilities. There are presented some countries that do the compensation, financial or not, for some municipalities for the construction of waste deposits and in some cases, the way that occurred the negotiation between the stake holders, in other words, the local population and the companies. Also are presented others forms of financial compensation in Brazil in consequence of activities in large scale which result in potential risk for the surrounding population and for the environment, like compensation for oil and natural gas, hydropower plants and mining. Were used on methodology the inventory of waste presented on RMBN project (Repository of Waste of Low and Medium Activity) developed by the CDTN which present the implementation of a repository for final storage to radioactive waste. With this was possible to develop a case study with the creation of four scenarios. Values were found which initially range from R$2,6 thousand to R$79,8 thousand for month. Finally are analyzed the possible influences which that values may have on the municipality budget revenue and some divergent points about the resolution. (author)

  9. Financial compensation due to municipalities that host radioactive waste deposits

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Renata A. da; Simoes, Francisco Fernando L.; Martins, Vivian B., E-mail: renata.amaral@ufrj.br, E-mail: flamego@ien.gov.br, E-mail: vbmartins@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This work aims to perform calculation about the financial compensation due to municipalities where there is viability for construction of radioactive waste deposits from low and medium activity. Were used like base structure de Resolution No. 96 of August, 10, 2010, entitled 'Model of Calculation For Financial Compensation to Municipalities' where are determinate those principal characteristics by the waste and deposits, such as the half-life, activity level, type of deposits (initial, intermediate or final), costs for construction and maintenance of deposits, demography, between others. The calculation was made according to the temporally or definitive storage for solids waste like personal protection equipment (gloves, shoes, masks, etc) resins and filters used in wastewater treatment, between others, from of nuclear and radioactivity facilities. There are presented some countries that do the compensation, financial or not, for some municipalities for the construction of waste deposits and in some cases, the way that occurred the negotiation between the stake holders, in other words, the local population and the companies. Also are presented others forms of financial compensation in Brazil in consequence of activities in large scale which result in potential risk for the surrounding population and for the environment, like compensation for oil and natural gas, hydropower plants and mining. Were used on methodology the inventory of waste presented on RMBN project (Repository of Waste of Low and Medium Activity) developed by the CDTN which present the implementation of a repository for final storage to radioactive waste. With this was possible to develop a case study with the creation of four scenarios. Values were found which initially range from R$2,6 thousand to R$79,8 thousand for month. Finally are analyzed the possible influences which that values may have on the municipality budget revenue and some divergent points about the resolution. (author)

  10. Gamma exposures due to radionuclides deposited in urban environments: Pt. 1

    International Nuclear Information System (INIS)

    Meckbach, R.; Jacob, P.; Paretzke, H.G.

    1988-01-01

    The modification of gamma exposure from deposited activity at locations inside and outside of buildings in urban environments compared with unshielded locations has been computed using the Monte Carlo method. The types of buildings considered were a house of prefabricated parts, a semi-detached house, a row of four large terrace houses and a multistorey house block. The computations were performed for source energies of 0.3 MeV, 0.662 MeV and 3.0 MeV. In this first part of the paper results for the kerma at various locations inside and outside the buildings due to a contamination with unit surface activity are presented separately for each of the various deposition areas such as walls, windows, roofs, light shafts, paved areas, lawns, and trees. (author)

  11. Building of nested components by a double-nozzle droplet deposition process

    Science.gov (United States)

    Li, SuLi; Wei, ZhengYing; Du, Jun; Zhao, Guangxi; Wang, Xin; Lu, BingHeng

    2016-07-01

    According to the nested components jointed with multiple parts,a double-nozzle droplet deposition process was put forward in this paper, and the experimental system was developed. Through the research on the properties of support materials and the process of double-nozzle droplet deposition, the linkage control of the metal droplet deposition and the support material extrusion was realized, and a nested component with complex construction was fabricated directly. Compared with the traditional forming processes, this double-nozzle deposition process has the advantages of short cycle, low cost and so on. It can provide an approach way to build the nested parts.

  12. Advances in the electro-spark deposition coating process

    International Nuclear Information System (INIS)

    Johnson, R.N.; Sheldon, G.L.

    1986-04-01

    Electro-spark deposition (ESD) is a pulsed-arc micro-welding process using short-duration, high-current electrical pulses to deposit an electrode material on a metallic substrate. It is one of the few methods available by which a fused, metallurgically bonded coating can be applied with such a low total heat input that the bulk substrate material remains at or near ambient temperatures. The short duration of the electrical pulse allows an extremely rapid solidification of the deposited material and results in an exceptionally fine-grained, homogenous coating that approaches (and with some materials, actually is) an amorphous structure. This structure is believed to contribute to the good tribological and corrosion performance observed for hardsurfacing materials used in the demanding environments of high temperatures, liquid metals, and neutron irradiation. A brief historical review of the process is provided, followed by descriptions of the present state-of-the-art and of the performance and applications of electro-spark deposition coatings in liquid-metal-cooled nuclear reactors

  13. Modeling of gas flow and deposition profile in HWCVD processes

    Energy Technology Data Exchange (ETDEWEB)

    Pflug, Andreas; Höfer, Markus; Harig, Tino; Armgardt, Markus; Britze, Chris; Siemers, Michael; Melzig, Thomas; Schäfer, Lothar

    2015-11-30

    Hot wire chemical vapor deposition (HWCVD) is a powerful technology for deposition of high quality films on large area, where drawbacks of plasma based technology such as defect generation by ion bombardment and high equipment costs are omitted. While processes for diamond coatings using H{sub 2} and CH{sub 4} as precursor have been investigated in detail since 1990 and have been transferred to industry, research also focuses on silicon based coatings with H{sub 2}, SiH{sub 4} and NH{sub 3} as process gases. HWCVD of silicon based coatings is a promising alternative for state-of-the-art radiofrequency-plasma enhanced chemical vapor deposition reactors. The film formation in HWCVD results from an interaction of several concurrent chemical reactions such as gas phase chemistry, film deposition, abstraction of surplus hydrogen bonds and etching by atomic hydrogen. Since there is no easy relation between process parameters and resulting deposition profiles, substantial experimental effort is required to optimize the process for a given film specification and the desired film uniformity. In order to obtain a deeper understanding of the underlying mechanisms and to enable an efficient way of process optimization, simulation methods come into play. While diamond deposition occurs at pressures in the range of several kPa HWCVD deposition of Si based coatings operates at pressures in the 0.1–30 Pa range. In this pressure regime, particle based simulation methods focused on solving the Boltzmann equation are computationally feasible. In comparison to computational fluid dynamics this yields improved accuracy even near small gaps or orifices, where characteristic geometric dimensions approach the order of the mean free path of gas molecules. At Fraunhofer IST, a parallel implementation of the Direct Simulation Monte Carlo (DSMC) method extended by a reactive wall chemistry model is developed. To demonstrate the feasibility of three-dimensional simulation of HWCVD processes

  14. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    CERN Document Server

    Martins, D R; Verdonck, P; Brown, I G

    2002-01-01

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

  15. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    International Nuclear Information System (INIS)

    Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

    2002-01-01

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the stopping and range of ions in matter code. We find film contamination of the order of 10 -4 -10 -3 , and the memory of the prior history of the deposition hardware can be relatively long lasting

  16. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    Energy Technology Data Exchange (ETDEWEB)

    Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

    2002-08-13

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

  17. The influence of annealing on yttrium oxide thin film deposited by reactive magnetron sputtering: Process and microstructure

    Directory of Open Access Journals (Sweden)

    Y. Mao

    2017-01-01

    Full Text Available Yttrium oxide thin films were prepared by reactive magnetron sputtering in different deposition condition with various oxygen flow rates. The annealing influence on the yttrium oxide film microstructure is investigated. The oxygen flow shows a hysteresis behavior on the deposition rate. With a low oxygen flow rate, the so called metallic mode process with a high deposition rate (up to 1.4µm/h was achieved, while with a high oxygen flow rate, the process was considered to be in the poisoned mode with an extremely low deposition rate (around 20nm/h. X-ray diffraction (XRD results show that the yttrium oxide films that were produced in the metallic mode represent a mixture of different crystal structures including the metastable monoclinic phase and the stable cubic phase, while the poisoned mode products show a dominating monoclinic phase. The thin films prepared in metallic mode have relatively dense structures with less porosity. Annealing at 600 °C for 15h, as a structure stabilizing process, caused a phase transformation that changes the metastable monoclinic phase to stable cubic phase for both poisoned mode and metallic mode. The composition of yttrium oxide thin films changed from nonstoichiometric to stoichiometric together with a lattice parameter variation during annealing process. For the metallic mode deposition however, cracks were formed due to the thermal expansion coefficient difference between thin film and the substrate material which was not seen in poisoned mode deposition. The yttrium oxide thin films that deposited in different modes give various application options as a nuclear material.

  18. Development of a new process for deposition of metallic vapours and ions

    International Nuclear Information System (INIS)

    Gabrielli, O. de.

    1989-01-01

    Surface treatment processes by deposition, enabling surface properties to be altered without altering the volume, are making rapid progress in industry. The description of these processes has led us to consider the role and the importance of methods using plasmas. The new plasma source we have developed is the subject of this experimental research: it is the basis of the deposition process (metallic ion and vapour deposition). The specifications and preliminary results enable us to compare this process with others in use. Fast deposition rates and excellent adhesion are the two main characteristics of this process [fr

  19. TC17 titanium alloy laser melting deposition repair process and properties

    Science.gov (United States)

    Liu, Qi; Wang, Yudai; Zheng, Hang; Tang, Kang; Li, Huaixue; Gong, Shuili

    2016-08-01

    Due to the high manufacturing cost of titanium compressor blisks, aero engine repairing process research has important engineering significance and economic value. TC17 titanium alloy is a rich β stable element dual α+β phase alloy whose nominal composition is Ti-5Al-2Sn-2Zr-4Mo-4Cr. It has high mechanical strength, good fracture toughness, high hardenability and a wide forging-temperature range. Through a surface response experiment with different laser powers, scanning speeds and powder feeding speeds, the coaxial powder feeding laser melting deposition repair process is studied for the surface circular groove defects. In this paper, the tensile properties, relative density, microhardness, elemental composition, internal defects and microstructure of the laser-repaired TC17 forging plate are analyzed. The results show that the laser melting deposition process could realize the form restoration of groove defect; tensile strength and elongation could reach 1100 MPa and 10%, which could reach 91-98% that of original TC17 wrought material; with the optimal parameters (1000 W-25 V-8 mm/s), the microhardness of the additive zone, the heat-affected zone and base material is evenly distributed at 370-390 HV500. The element content difference between the additive zone and base material is less than ±0.15%. Due to the existence of the pores 10 μm in diameter, the relative density could reach 99%, which is mainly inversely proportional to the powder feeding speed. The repaired zone is typically columnar and dendrite crystal, and the 0.5-1.5 mm-deep heat-affected zone in the groove interface is coarse equiaxial crystal.

  20. Biochemical processes of oligotrophic peat deposits of Vasyugan Mire

    Science.gov (United States)

    Inisheva, L. I.; Sergeeva, M. A.

    2009-04-01

    The problem of peat and mire ecosystems functioning and their rational use is the main problem of biosphere study. This problem also refers to forecasting of biosphere changes results which are global and anthropogenic. According to many scientists' research the portion of mires in earth carbon balance is about 15% of world's stock. The aim of this study is to investigate biochemical processes in oligotrophic deposits in North-eastern part of Vasyugan Mire. The investigations were made on the territory of scientific-research ground (56˚ 03´ and 56˚ 57´ NL, 82˚ 22´ and 82˚ 42´ EL). It is situated between two rivers Bakchar and Iksa (in outskirts of the village Polynyanka, Bakchar region, Tomsk oblast). Evolution of investigated mire massif began with the domination of eutrophic phytocenosis - Filicinae, then sedge. Later transfer into oligotrophic phase was accompanied by formation of meter high-moor peat deposit. The age of three-meter peat deposit reaches four thousand years. Biochemical processes of carbon cycle cover the whole peat deposit, but the process activity and its direction in different layers are defined by genesis and duration of peat formation. So, the number of cellulose-fermenting aerobes in researched peat deposits ranges from 16.8 to 75.5 million CFU/g, and anaerobic bacteria from 9.6 to 48.6 million CFU/g. The high number of aerobes is characteristic for high water levels, organizing by raised bog peats. Their number decreases along the profile in 1.7 - 2 times. The number of microflora in peat deposit is defined by the position in the landscape profile (different geneses), by the depth, by hydrothermic conditions of years and individual months. But microflora activity shows along all depth of peat deposit. We found the same in the process of studying of micromycete complex structure. There was revealed either active component micromycete complex - mycelium, or inert one - spores in a meter layer of peat deposit. If mushrooms

  1. Low-pressure c-BN deposition - is a CVD process possible?

    International Nuclear Information System (INIS)

    Haubner, R.; Tang, X.

    2001-01-01

    Since the low-pressure diamond deposition was discovered in 1982 there is a high interest to find a similar process for the c-BN synthesis. A review about the c-BN deposition process as well as its characterization is given. Experiments with a simple chemical vapor deposition(CVD) reactor using tris(dimethylamino)borane as precursor were carried out. In a cold-wall reactor substrates were heated up by high-frequency. Argon was used as protecting and carrying the precursor, it was saturated with tris(dimethylamino)borane (precursor) according to its vapor pressure and transports the pressure to the hot substrate, where deposition occurs. WC-Co hardmetal plates containing 6 wt. % Co, Mo and Si were used as substrates. Various BN layers were deposited and characterized. X-ray diffraction, IR-spectroscopy and SIMS indicate that BN-coatings containing c-BN were deposited. However a final verification of c-BN crystallites by TEM investigations was not possible till now. (nevyjel)

  2. A review: deposition and resuspension processes

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1979-01-01

    A review chapter was written on deposition and resuspension processes for the forthcoming Department of Energy publication, Atmospheric Sciences and Power Production, edited by D. Randerson. The chapter includes eleven tables and thirteen figures summarizing data from 241 references. The conclusions of that review chapter are given

  3. Effects of acid deposition on microbial processes in natural waters

    International Nuclear Information System (INIS)

    Gilmour, C.C.

    1992-01-01

    Biogeochemical processes mediated by microorganisms are not adversely affected by the acidification of natural waters to the same extent as are the life cycles of higher organisms. Basic processes, e.g., primary production and organic matter decomposition, are not slowed in moderately acidified systems and do not generally decline above a pH of 5. More specifically, the individual components of the carbon, nitrogen, and sulfur cycles are, with few exceptions, also acid resistant. The influence of acid deposition on microbial processes is more often stimulation of nitrogen and sulfur cycling, often leading to alkalinity production, which mitigates the effect of strong acid deposition. Bacterial sulfate reduction and denitrification in sediments are two of the major processes that can be stimulated by sulfate and nitrate deposition, respectively, and result in ANC (acid-neutralizing capacity) generation. One of the negative effects of acid deposition is increased mobilization and bioaccumulation of some metals. Bacteria appear to play an important role, especially in mercury cycling, with acidification leading to increased bacterial methylation of mercury and subsequent bioaccumulation in higher organisms

  4. PVD processes of thin films deposition using Hall-current discharge

    International Nuclear Information System (INIS)

    Svadkovskij, I.V.

    2007-01-01

    Results of research and developments in the field of PVD processes of thin films deposition using Hall-current discharge have been summarized. Effects of interaction of ions with surface during deposition have been considered. Also features of application and prospects of devices based on ion beam and magnetron sputtering systems in thin films technologies have been analyzed. The aspects in the field plasma physics, technology and equipment plasma PVD processes of thin films deposition have been systematized, on the base of investigations made by author and other scientists. (authors)

  5. Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    Science.gov (United States)

    Lackey, Jr., Walter J.; Caputo, Anthony J.

    1986-01-01

    A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

  6. Constitutional Due Process and Educational Administration.

    Science.gov (United States)

    Uerling, Donald F.

    1985-01-01

    Discusses substantive and procedural due process as required by the United States Constitution and interpreted by the Supreme Court, with particular reference to situations arising in educational environments. Covers interests protected by due process requirements, the procedures required, and some special considerations that may apply. (PGD)

  7. Use of process indices for simplification of the description of vapor deposition systems

    International Nuclear Information System (INIS)

    Kajikawa, Yuya; Noda, Suguru; Komiyama, Hiroshi

    2004-01-01

    Vapor deposition is a complex process, including gas-phase, surface, and solid-phase phenomena. Because of the complexity of chemical and physical processes occurring in vapor deposition processes, it is difficult to form a comprehensive, fundamental understanding of vapor deposition and to control such systems for obtaining desirable structures and performance. To overcome this difficulty, we present a method for simplifying the complex description of such systems. One simplification method is to separate complex systems into multiple elements, and determine which of these are important elements. We call this method abridgement. The abridgement method retains only the dominant processes in a description of the system, and discards the others. Abridgement can be achieved by using process indices to evaluate the relative importance of the elementary processes. We describe the formulation and use of these process indices through examples of the growth of continuous films, initial deposition processes, and the formation of the preferred orientation of polycrystalline films. In this paper, we propose a method for representing complex vapor deposition processes as a set of simpler processes

  8. Fabrication of an a-IGZO thin film transistor using selective deposition of cobalt by the self-assembly monolayer (SAM) process.

    Science.gov (United States)

    Cho, Young-Je; Kim, HyunHo; Park, Kyoung-Yun; Lee, Jaegab; Bobade, Santosh M; Wu, Fu-Chung; Choi, Duck-Kyun

    2011-01-01

    Interest in transparent oxide thin film transistors utilizing ZnO material has been on the rise for many years. Recently, however, IGZO has begun to draw more attention due to its higher stability and superior electric field mobility when compared to ZnO. In this work, we address an improved method for patterning an a-IGZO film using the SAM process, which employs a cost-efficient micro-contact printing method instead of the conventional lithography process. After a-IGZO film deposition on the surface of a SiO2-layered Si wafer, the wafer was illuminated with UV light; sources and drains were then patterned using n-octadecyltrichlorosilane (OTS) molecules by a printing method. Due to the low surface energy of OTS, cobalt was selectively deposited on the OTS-free a-IGZO surface. The selective deposition of cobalt electrodes was successful, as confirmed by an optical microscope. The a-IZGO TFT fabricated using the SAM process exhibited good transistor performance: electric field mobility (micro(FE)), threshold voltage (V(th)), subthreshold slope (SS) and on/off ratio were 2.1 cm2/Vs, 2.4 V, 0.35 V/dec and 2.9 x 10(6), respectively.

  9. Influence of substrate geometry on ion-plasma coating deposition process

    International Nuclear Information System (INIS)

    Khoroshikh, V.M.; Leonov, S.A.; Belous, V.A.

    2008-01-01

    Influence of substrate geometry on the feature of Ti vacuum arc plasma streams condensation process in presence of N 2 or Ar in a discharge ambient were investigated. Character of gas pressure and substrate potential influence on deposition rate is conditioned the competitive processes of condensation and sputtering, and also presence of double electric layer on a border plasma-substrate. Influence of potential on deposition rate especially strongly shows up for cylindrical substrates of small size. For such substrates it was found substantial (approximately in 4 times) growth of deposition rate at the increasing of negative potential from 100 to 700 V when nitrogen pressure is ∼0,3...2,5 Pa. Possibility of droplet-free coating deposition the substrate backs and in discharge ambient, being outside area of cathode direct visibility is shown

  10. Water evaporation in silica colloidal deposits.

    Science.gov (United States)

    Peixinho, Jorge; Lefèvre, Grégory; Coudert, François-Xavier; Hurisse, Olivier

    2013-10-15

    The results of an experimental study on the evaporation and boiling of water confined in the pores of deposits made of mono-dispersed silica colloidal micro-spheres are reported. The deposits are studied using scanning electron microscopy, adsorption of nitrogen, and adsorption of water through attenuated total reflection-infrared spectroscopy. The evaporation is characterized using differential scanning calorimetry and thermal gravimetric analysis. Optical microscopy is used to observe the patterns on the deposits after evaporation. When heating at a constant rate and above boiling temperature, the release of water out of the deposits is a two step process. The first step is due to the evaporation and boiling of the surrounding and bulk water and the second is due to the desorption of water from the pores. Additional experiments on the evaporation of water from membranes having cylindrical pores and of heptane from silica deposits suggest that the second step is due to the morphology of the deposits. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Cesium-137 deposition and contamination of Japanese soils due to the Fukushima nuclear accident.

    Science.gov (United States)

    Yasunari, Teppei J; Stohl, Andreas; Hayano, Ryugo S; Burkhart, John F; Eckhardt, Sabine; Yasunari, Tetsuzo

    2011-12-06

    The largest concern on the cesium-137 ((137)Cs) deposition and its soil contamination due to the emission from the Fukushima Daiichi Nuclear Power Plant (NPP) showed up after a massive quake on March 11, 2011. Cesium-137 ((137)Cs) with a half-life of 30.1 y causes the largest concerns because of its deleterious effect on agriculture and stock farming, and, thus, human life for decades. Removal of (137)Cs contaminated soils or land use limitations in areas where removal is not possible is, therefore, an urgent issue. A challenge lies in the fact that estimates of (137)Cs emissions from the Fukushima NPP are extremely uncertain, therefore, the distribution of (137)Cs in the environment is poorly constrained. Here, we estimate total (137)Cs deposition by integrating daily observations of (137)Cs deposition in each prefecture in Japan with relative deposition distribution patterns from a Lagrangian particle dispersion model, FLEXPART. We show that (137)Cs strongly contaminated the soils in large areas of eastern and northeastern Japan, whereas western Japan was sheltered by mountain ranges. The soils around Fukushima NPP and neighboring prefectures have been extensively contaminated with depositions of more than 100,000 and 10,000 MBq km(-2), respectively. Total (137)Cs depositions over two domains: (i) the Japan Islands and the surrounding ocean (130-150 °E and 30-46 °N) and, (ii) the Japan Islands, were estimated to be approximately 6.7 and 1.3 PBq, [corrected] respectively.We hope our (137)Cs deposition maps will help to coordinate decontamination efforts and plan regulatory measures in Japan.

  12. On the processing-structure-property relationship of ITO layers deposited on crystalline and amorphous Si

    International Nuclear Information System (INIS)

    Diplas, S.; Ulyashin, A.; Maknys, K.; Gunnaes, A.E.; Jorgensen, S.; Wright, D.; Watts, J.F.; Olsen, A.; Finstad, T.G.

    2007-01-01

    Indium-tin-oxide (ITO) antireflection coatings were deposited on crystalline Si (c-Si), amorphous hydrogenated Si (a-Si:H) and glass substrates at room temperature (RT), 160 deg. C and 230 deg. C by magnetron sputtering. The films were characterised using atomic force microscopy, transmission electron microscopy, angle resolved X-ray photoelectron spectroscopy, combined with resistance and transmittance measurements. The conductivity and refractive index as well as the morphology of the ITO films showed a significant dependence on the processing conditions. The films deposited on the two different Si substrates at higher temperatures have rougher surfaces compared to the RT ones due to the development of crystallinity and growth of columnar grains

  13. Electro-deposition painting process improvement of cab truck by Six Sigma concept

    Science.gov (United States)

    Kawitu, Kitiya; Chutima, Parames

    2017-06-01

    The case study company is a manufacturer of trucks and currently facing a high rework cost due to the thickness of the electro-deposited paint (EDP) of the truck cab is lower than standard. In addition, the process capability is very low. The Six Sigma concept consisting of 5 phases (DMAIC) is applied to determine new parameter settings for each significant controllable factor. After the improvement, EDP thickness of the truck cab increases from 17.88μ to 20μ (i.e. standard = 20 ± 3μ). Moreover, the process capability indexes (Cp and Cpk) are increased from 0.9 to 1.43, and from 0.27 to 1.43, respectively. This improvement could save the rework cost about 1.6M THB per year.

  14. Gaseous material capacity of open plasma jet in plasma spray-physical vapor deposition process

    Science.gov (United States)

    Liu, Mei-Jun; Zhang, Meng; Zhang, Qiang; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

    2018-01-01

    Plasma spray-physical vapor deposition (PS-PVD) process, emerging as a highly efficient hybrid approach, is based on two powerful technologies of both plasma spray and physical vapor deposition. The maximum production rate is affected by the material feed rate apparently, but it is determined by the material vapor capacity of transporting plasma actually and essentially. In order to realize high production rate, the gaseous material capacity of plasma jet must be fundamentally understood. In this study, the thermal characteristics of plasma were measured by optical emission spectrometry. The results show that the open plasma jet is in the local thermal equilibrium due to a typical electron number density from 2.1 × 1015 to 3.1 × 1015 cm-3. In this condition, the temperature of gaseous zirconia can be equal to the plasma temperature. A model was developed to obtain the vapor pressure of gaseous ZrO2 molecules as a two dimensional map of jet axis and radial position corresponding to different average plasma temperatures. The overall gaseous material capacity of open plasma jet, take zirconia for example, was further established. This approach on evaluating material capacity in plasma jet would shed light on the process optimization towards both depositing columnar coating and a high production rate of PS-PVD.

  15. Nitrogen deposition in precipitation to a monsoon-affected eutrophic embayment: Fluxes, sources, and processes

    Science.gov (United States)

    Wu, Yunchao; Zhang, Jingping; Liu, Songlin; Jiang, Zhijian; Arbi, Iman; Huang, Xiaoping; Macreadie, Peter Ian

    2018-06-01

    Daya Bay in the South China Sea (SCS) has experienced rapid nitrogen pollution and intensified eutrophication in the past decade due to economic development. Here, we estimated the deposition fluxes of nitrogenous species, clarified the contribution of nitrogen from precipitation and measured ions and isotopic composition (δ15N and δ18O) of nitrate in precipitation in one year period to trace its sources and formation processes among different seasons. We found that the deposition fluxes of total dissolved nitrogen (TDN), NO3-, NH4+, NO2-, and dissolved organic nitrogen (DON) to Daya Bay were 132.5, 64.4 17.5, 1.0, 49.6 mmol m-2•yr-1, respectively. DON was a significant contributor to nitrogen deposition (37% of TDN), and NO3- accounted for 78% of the DIN in precipitation. The nitrogen deposition fluxes were higher in spring and summer, and lower in winter. Nitrogen from precipitation contributed nearly 38% of the total input of nitrogen (point sources input and dry and wet deposition) in Daya Bay. The δ15N-NO3- abundance, ion compositions, and air mass backward trajectories implicated that coal combustion, vehicle exhausts, and dust from mainland China delivered by northeast monsoon were the main sources in winter, while fossil fuel combustion (coal combustion and vehicle exhausts) and dust from PRD and southeast Asia transported by southwest monsoon were the main sources in spring; marine sources, vehicle exhausts and lightning could be the potential sources in summer. δ18O results showed that OH pathway was dominant in the chemical formation process of nitrate in summer, while N2O5+ DMS/HC pathways in winter and spring.

  16. Sources and processes contributing to nitrogen deposition: an adjoint model analysis applied to biodiversity hotspots worldwide.

    Science.gov (United States)

    Paulot, Fabien; Jacob, Daniel J; Henze, Daven K

    2013-04-02

    Anthropogenic enrichment of reactive nitrogen (Nr) deposition is an ecological concern. We use the adjoint of a global 3-D chemical transport model (GEOS-Chem) to identify the sources and processes that control Nr deposition to an ensemble of biodiversity hotspots worldwide and two U.S. national parks (Cuyahoga and Rocky Mountain). We find that anthropogenic sources dominate deposition at all continental sites and are mainly regional (less than 1000 km) in origin. In Hawaii, Nr supply is controlled by oceanic emissions of ammonia (50%) and anthropogenic sources (50%), with important contributions from Asia and North America. Nr deposition is also sensitive in complicated ways to emissions of SO2, which affect Nr gas-aerosol partitioning, and of volatile organic compounds (VOCs), which affect oxidant concentrations and produce organic nitrate reservoirs. For example, VOC emissions generally inhibit deposition of locally emitted NOx but significantly increase Nr deposition downwind. However, in polluted boreal regions, anthropogenic VOC emissions can promote Nr deposition in winter. Uncertainties in chemical rate constants for OH + NO2 and NO2 hydrolysis also complicate the determination of source-receptor relationships for polluted sites in winter. Application of our adjoint sensitivities to the representative concentration pathways (RCPs) scenarios for 2010-2050 indicates that future decreases in Nr deposition due to NOx emission controls will be offset by concurrent increases in ammonia emissions from agriculture.

  17. Effect of Energy Input on the Characteristic of AISI H13 and D2 Tool Steels Deposited by a Directed Energy Deposition Process

    Science.gov (United States)

    Park, Jun Seok; Park, Joo Hyun; Lee, Min-Gyu; Sung, Ji Hyun; Cha, Kyoung Je; Kim, Da Hye

    2016-05-01

    Among the many additive manufacturing technologies, the directed energy deposition (DED) process has attracted significant attention because of the application of metal products. Metal deposited by the DED process has different properties than wrought metal because of the rapid solidification rate, the high thermal gradient between the deposited metal and substrate, etc. Additionally, many operating parameters, such as laser power, beam diameter, traverse speed, and powder mass flow rate, must be considered since the characteristics of the deposited metal are affected by the operating parameters. In the present study, the effect of energy input on the characteristics of H13 and D2 steels deposited by a direct metal tooling process based on the DED process was investigated. In particular, we report that the hardness of the deposited H13 and D2 steels decreased with increasing energy input, which we discuss by considering microstructural observations and thermodynamics.

  18. Electron pulsed beam induced processing of thin film surface by Nb3Ge deposited into a stainless steel tape

    International Nuclear Information System (INIS)

    Vavra, I.; Korenev, S.A.

    1988-01-01

    A surface of superconductive thin film of Nb 3 Ge deposited onto a stainless steel tape was processed using the electron beam technique. The electron beam used had the following parameters: beam current density from 400 to 1000 A/cm 2 ; beam energy 100 keV; beam impulse length 300 ns. By theoretical analysis it is shown that the heating of film surface is an adiabatic process. It corresponds to our experimental data and pictures showing a surface remelting due to electron beam influence. After beam processing the superconductive parameters of the film remain unchanged. Roentgenograms have been analysed of Nb 3 Ge film surface recrystallized due to electron beam influence

  19. Procedural Due Process Rights in Student Discipline.

    Science.gov (United States)

    Pressman, Robert; Weinstein, Susan

    To assist administrators in understanding procedural due process rights in student discipline, this manual draws together hundreds of citations and case summaries of federal and state court decisions and provides detailed commentary as well. Chapter 1 outlines the general principles of procedural due process rights in student discipline, such as…

  20. Surface coatings deposited by CVD and PVD

    International Nuclear Information System (INIS)

    Gabriel, H.M.

    1982-01-01

    The demand for wear and corrosion protective coatings is increasing due to economic facts. Deposition processes in gas atmospheres like the CVD and PVD processes attained a tremendous importance especially in the field of the deposition of thin hard refractory and ceramic coatings. CVD and PVD processes are reviewed in detail. Some examples of coating installations are shown and numerous applications are given to demonstrate the present state of the art. (orig.) [de

  1. 49 CFR 594.9 - Fee for reimbursement of bond processing costs and costs for processing offers of cash deposits...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Fee for reimbursement of bond processing costs and costs for processing offers of cash deposits or obligations of the United States in lieu of sureties on... indirect costs the agency incurs for receipt, processing, handling, and disbursement of cash deposits or...

  2. Particle deposition due to turbulent diffusion in the upper respiratory system

    Science.gov (United States)

    Hamill, P.

    1979-01-01

    Aerosol deposition in the upper respiratory system (trachea to segmental bronchi) is considered and the importance of turbulent diffusion as a deposition mechanism is evaluated. It is demonstrated that for large particles (diameter greater than about 5 microns), turbulent diffusion is the dominant deposition mechanism in the trachea. Conditions under which turbulent diffusion may be important in successive generations of the pulmonary system are determined. The probability of particle deposition is compared with probabilities of deposition, as determined by the equations generally used in regional deposition models. The analysis is theoretical; no new experimental data is presented.

  3. Influence of Oxygen Partial Pressure during Processing on the Thermoelectric Properties of Aerosol-Deposited CuFeO₂.

    Science.gov (United States)

    Stöcker, Thomas; Exner, Jörg; Schubert, Michael; Streibl, Maximilian; Moos, Ralf

    2016-03-24

    In the field of thermoelectric energy conversion, oxide materials show promising potential due to their good stability in oxidizing environments. Hence, the influence of oxygen partial pressure during synthesis on the thermoelectric properties of Cu-Delafossites at high temperatures was investigated in this study. For these purposes, CuFeO₂ powders were synthetized using a conventional mixed-oxide technique. X-ray diffraction (XRD) studies were conducted to determine the crystal structures of the delafossites associated with the oxygen content during the synthesis. Out of these powders, films with a thickness of about 25 µm were prepared by the relatively new aerosol-deposition (AD) coating technique. It is based on a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. On these dense CuFeO₂ films deposited on alumina substrates with electrode structures, the Seebeck coefficient and the electrical conductivity were measured as a function of temperature and oxygen partial pressure. We compared the thermoelectric properties of both standard processed and aerosol deposited CuFeO₂ up to 900 °C and investigated the influence of oxygen partial pressure on the electrical conductivity, on the Seebeck coefficient and on the high temperature stability of CuFeO₂. These studies may not only help to improve the thermoelectric material in the high-temperature case, but may also serve as an initial basis to establish a defect chemical model.

  4. Sedimentation rates and depositional processes in Lake Superior from 210Pb geochronology

    International Nuclear Information System (INIS)

    Evans, J.E.; Johnson, T.C.; Alexander, E.C. Jr.; Lively, R.S.; Eisenreich, S.J.

    1981-01-01

    Sedimentation rates range from 0.01 to 0.32 cm/yr in 17 sediment box cores from Lake Superior, as determined by 210 Pb geochronology. Shoreline erosion and resuspension of nearshore sediments causes moderate to high (0.05-0.11 cm/yr) sedimentation rates in the western arm of Lake Superior. Sedimentation rates are very high (> 0.15 cm/yr) in marginal bays adjoining Lake Superior; and moderate to very high (0.07-0.19 cm/yr) in open lake regions adjacent to marginal bays. Resuspension of nearshore and shoal top sediments in southern and southeastern Lake Superior by storms is responsible for depositional anomalies in 210 Pb profiles corresponding to 1905, 1916-1918, and 1940 storms. Sedimentation rates are very low (0.01-0.03 cm/yr) in the central basins due to isolation from sediment sources. These data indicate that sedimentation rates and processes vary significantly in different regions of Lake Superior. The sedimentation rates provided by this study, in conjunction with previously-reported sedimentation rates, yield a better understanding of the Lake Superior depositional environment

  5. Simulation of enhanced deposition due to magnetic field alignment of ellipsoidal particles in a lung bifurcation.

    Science.gov (United States)

    Martinez, R C; Roshchenko, A; Minev, P; Finlay, W H

    2013-02-01

    Aerosolized chemotherapy has been recognized as a potential treatment for lung cancer. The challenge of providing sufficient therapeutic effects without reaching dose-limiting toxicity levels hinders the development of aerosolized chemotherapy. This could be mitigated by increasing drug-delivery efficiency with a noninvasive drug-targeting delivery method. The purpose of this study is to use direct numerical simulations to study the resulting local enhancement of deposition due to magnetic field alignment of high aspect ratio particles. High aspect ratio particles were approximated by a rigid ellipsoid with a minor diameter of 0.5 μm and fluid particle density ratio of 1,000. Particle trajectories were calculated by solving the coupled fluid particle equations using an in-house micro-macro grid finite element algorithm based on a previously developed fictitious domain approach. Particle trajectories were simulated in a morphologically realistic geometry modeling a symmetrical terminal bronchiole bifurcation. Flow conditions were steady inspiratory air flow due to typical breathing at 18 L/min. Deposition efficiency was estimated for two different cases: [1] particles aligned with the streamlines and [2] particles with fixed angular orientation simulating the magnetic field alignment of our previous in vitro study. The local enhancement factor defined as the ratio between deposition efficiency of Case [1] and Case [2] was found to be 1.43 and 3.46 for particles with an aspect ratio of 6 and 20, respectively. Results indicate that externally forcing local alignment of high aspect ratio particles can increase local deposition considerably.

  6. Chemical vapor deposition graphene transfer process to a polymeric substrate assisted by a spin coater

    International Nuclear Information System (INIS)

    Kessler, Felipe; Da Rocha, Caique O C; Medeiros, Gabriela S; Fechine, Guilhermino J M

    2016-01-01

    A new method to transfer chemical vapor deposition graphene to polymeric substrates is demonstrated here, it is called direct dry transfer assisted by a spin coater (DDT-SC). Compared to the conventional method DDT, the improvement of the contact between graphene-polymer due to a very thin polymeric film deposited by spin coater before the transfer process prevented air bubbles and/or moisture and avoided molecular expansion on the graphene-polymer interface. An acrylonitrile-butadiene-styrene copolymer, a high impact polystyrene, polybutadiene adipate-co-terephthalate, polylactide acid, and a styrene-butadiene-styrene copolymer are the polymers used for the transfers since they did not work very well by using the DDT process. Raman spectroscopy and optical microscopy were used to identify, to quantify, and to qualify graphene transferred to the polymer substrates. The quantity of graphene transferred was substantially increased for all polymers by using the DDT-SC method when compared with the DDT standard method. After the transfer, the intensity of the D band remained low, indicating low defect density and good quality of the transfer. The DDT-SC transfer process expands the number of graphene applications since the polymer substrate candidates are increased. (paper)

  7. Rapid deposition process for zinc oxide film applications in pyroelectric devices

    International Nuclear Information System (INIS)

    Hsiao, Chun-Ching; Yu, Shih-Yuan

    2012-01-01

    Aerosol deposition (AD) is a rapid process for the deposition of films. Zinc oxide is a low toxicity and environmentally friendly material, and it possesses properties such as semiconductivity, pyroelectricity and piezoelectricity without the poling process. Therefore, AD is used to accelerate the manufacturing process for applications of ZnO films in pyroelectric devices. Increasing the temperature variation rate in pyroelectric films is a useful method for enhancing the responsivity of pyroelectric devices. In the present study, a porous ZnO film possessing the properties of large heat absorption and high temperature variation rate is successfully produced by the AD rapid process and laser annealing for application in pyroelectric devices. (paper)

  8. Deposition of polymeric perfluored thin films in proton ionic membranes by plasma processes

    International Nuclear Information System (INIS)

    Polak, Peter Lubomir; Mousinho, Ana Paula; Ordonez, Nelson; Silva Zambom, Luis da; Mansano, Ronaldo Domingues

    2007-01-01

    In this work the surfaces of polymeric membranes based on Nafion (proton conducting material), used in proton exchange membranes fuel cells (PEMFC) had been modified by plasma deposition of perfluored polymers, in order to improve its functioning in systems of energy generation (fuel cells). The deposition increases the chemical resistance of the proton ionic polymers without losing the electrical properties. The processing of the membranes also reduces the permeability of the membranes to the alcohols (methanol and ethanol), thus preventing poisoning of the fuel cell. The processing of the membranes of Nafion was carried through in a system of plasma deposition using a mixture of CF 4 and H 2 gases. The plasma processing was made mainly to increase the chemical resistance and result in hydrophobic surfaces. The Fourier transformed infrared (FTIR) technique supplies a spectrum with information about the CF n bond formation. Through the Rutherford back scattering (RBS) technique it was possible to verify the deposition rate of the polymeric layer. The plasma process with composition of 60% of CF 4 and 40% of H 2 presented the best deposition rate. By the spectrum analysis for the optimized configuration, it was possible to verify that the film deposition occurred with a thickness of 90 nm, and fluorine concentration was nearly 30%. Voltammetry made possible to verify that the fluorination increases the membranes chemical resistance, improving the stability of Nafion, becoming an attractive process for construction of fuel cells

  9. Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane: the role of dissociative ionization and dissociative electron attachment in the deposition process

    Directory of Open Access Journals (Sweden)

    Ragesh Kumar T P

    2017-11-01

    Full Text Available We present first experiments on electron beam induced deposition of silacyclohexane (SCH and dichlorosilacyclohexane (DCSCH under a focused high-energy electron beam (FEBID. We compare the deposition dynamics observed when growing pillars of high aspect ratio from these compounds and we compare the proximity effect observed for these compounds. The two precursors show similar behaviour with regards to fragmentation through dissociative ionization in the gas phase under single-collision conditions. However, while DCSCH shows appreciable cross sections with regards to dissociative electron attachment, SCH is inert with respect to this process. We discuss our deposition experiments in context of the efficiency of these different electron-induced fragmentation processes. With regards to the deposition dynamics, we observe a substantially faster growth from DCSCH and a higher saturation diameter when growing pillars with high aspect ratio. However, both compounds show similar behaviour with regards to the proximity effect. With regards to the composition of the deposits, we observe that the C/Si ratio is similar for both compounds and in both cases close to the initial molecular stoichiometry. The oxygen content in the DCSCH deposits is about double that of the SCH deposits. Only marginal chlorine is observed in the deposits of from DCSCH. We discuss these observations in context of potential approaches for Si deposition.

  10. Electromagnetic sensors for monitoring of scour and deposition processes at bridges and offshore wind turbines

    Science.gov (United States)

    Michalis, Panagiotis; Tarantino, Alessandro; Judd, Martin

    2014-05-01

    Recent increases in precipitation have resulted in severe and frequent flooding incidents. This has put hydraulic structures at high risk of failure due to scour, with severe consequences to public safety and significant economic losses. Foundation scour is the leading cause of bridge failures and one of the main climate change impacts to highway and railway infrastructure. Scour action is also being considered as a major risk for offshore wind farm developments as it leads to excessive excavation of the surrounding seabed. Bed level conditions at underwater foundations are very difficult to evaluate, considering that scour holes are often re-filled by deposited loose material which is easily eroded during smaller scale events. An ability to gather information concerning the evolution of scouring will enable the validation of models derived from laboratory-based studies and the assessment of different engineering designs. Several efforts have focused on the development of instrumentation techniques to measure scour processes at foundations. However, they are not being used routinely due to numerous technical and cost issues; therefore, scour continues to be inspected visually. This research project presents a new sensing technique, designed to measure scour depth variation and sediment deposition around the foundations of bridges and offshore wind turbines, and to provide an early warning of an impending structural failure. The monitoring system consists of a probe with integrated electromagnetic sensors, designed to detect the change in the surrounding medium around the foundation structure. The probe is linked to a wireless network to enable remote data acquisition. A developed prototype and a commercial sensor were evaluated to quantify their capabilities to detect scour and sediment deposition processes. Finite element modelling was performed to define the optimum geometric characteristics of the prototype scour sensor based on models with various permittivity

  11. Salt Separation from Uranium Deposits in Integrated Crucible

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. W.; Park, K. M.; Chang, J. H.; Kim, J. G.; Park, S. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. A physical separation process, such as distillation separation, is more attractive than a chemical or dissolution process because physical processes generate much less secondary process. Distillation process was employed for the cathode processsing due to the advantages of minimal generation of secondary waste, compact unit process, simple and low cost equipment. The basis for vacuum distillation separation is the difference in vapor pressures between salt and uranium. A solid cathode deposit is heated in a heating region and salt vaporizes, while non-volatile uranium remains behind. It is very important to increase the throughput of the salt separation system due to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. The evaporation rate of the LiCl-KCl eutectic salt in vacuum distiller is not so high to come up with the generation capacity of uranium dendrites in electro-refiner. Therefore, wide evaporation area or high distillation temperature is necessary for the successful salt separation. The adhered salt in the uranium deposits was removed successfully. The salt content in the deposits was below 0.1 wt% after the sequential operation of the liquid salt separation - salt distillation.

  12. Theoretical modelling of carbon deposition processes

    International Nuclear Information System (INIS)

    Marsh, G.R.; Norfolk, D.J.; Skinner, R.F.

    1985-01-01

    Work based on capsule experiments in the BNL Gamma Facility, aimed at elucidating the chemistry involved in the formation of carbonaceous deposit on CAGR fuel pin surfaces is described. Using a data-base derived from capsule experiments together with literature values for the kinetics of the fundamental reactions, a chemical model of the gas-phase processes has been developed. This model successfully reproduces the capsule results, whilst preliminary application to the WAGR coolant circuit indicates the likely concentration profiles of various radical species within the fuel channels. (author)

  13. Teacher Dismissal and Due Process.

    Science.gov (United States)

    Leichner, Edward C.; Blackstone, Sidney

    1977-01-01

    This article addresses due process requirements in the nonrenewal and dismissal of tenured and nontenured teachers. The Georgia Fair Dismissal Law is used as a basis for discussing the grounds for teacher dismissal. Dismissal grounds discussed are 1) incompetency; 2) insubordination; 3) willful neglect of duties; 4) immorality; 5) inciting,…

  14. Mangrove forests submitted to depositional processes and salinity variation investigated using satellite images and vegetation structure surveys

    OpenAIRE

    Cunha-Lignon, M.; Kampel, M.; Menghini, R.P.; Schaeffer-Novelli, Y.; Cintrón, G.; Dahdouh-Guebas, F.

    2011-01-01

    The current paper examines the growth and spatio-temporal variation of mangrove forests in response to depositional processes and different salinity conditions. Data from mangrove vegetation structure collected at permanent plots and satellite images were used. In the northern sector important environmental changes occurred due to an artificial channel producing modifications in salinity. The southern sector is considered the best conserved mangrove area along the coast of São Paulo State, Br...

  15. Deposition and surface treatment of Ag-embedded indium tin oxide by plasma processing

    International Nuclear Information System (INIS)

    Kim, Jun Young; Kim, Jae-Kwan; Kim, Ja-Yeon; Kwon, Min-Ki; Yoon, Jae-Sik; Lee, Ji-Myon

    2013-01-01

    Ag-embedded indium tin oxide (ITO) films were deposited on Corning 1737 glass by radio-frequency magnetron sputtering under an Ar or Ar/O 2 mixed gas ambient with a combination of ITO and Ag targets that were sputtered alternately by switching on and off the shutter of the sputter gun. The effects of a subsequent surface treatment using H 2 and H 2 + O 2 mixed gas plasma were also examined. The specific resistance of the as-deposited Ag-embedded ITO sample was lower than that of normal ITO. The transmittance was quenched when Ag was incorporated in ITO. To enhance the specific resistance of Ag-embedded ITO, a surface treatment was conducted using H 2 or H 2 + O 2 mixed gas plasma. Although all samples showed improved specific resistance after the H 2 plasma treatment, the transmittance was quenched due to the formation of agglomerated metals on the surface. The specific resistance of the film was improved without any deterioration of the transmittance after a H 2 + O 2 mixed gas plasma treatment. - Highlights: • Ag-embedded indium tin oxide was deposited. • The contact resistivity was decreased by H 2 + O 2 plasma treatment. • The process was carried out at room temperature without thermal treatment. • The mechanism of enhancing the contact resistance was clarified

  16. Analysis of heating effect on the process of high deposition rate microcrystalline silicon

    International Nuclear Information System (INIS)

    Xiao-Dan, Zhang; He, Zhang; Chang-Chun, Wei; Jian, Sun; Guo-Fu, Hou; Shao-Zhen, Xiong; Xin-Hua, Geng; Ying, Zhao

    2010-01-01

    A possible heating effect on the process of high deposition rate microcrystalline silicon has been studied. It includes the discharge time-accumulating heating effect, discharge power, inter-electrode distance, and total gas flow rate induced heating effect. It is found that the heating effects mentioned above are in some ways quite similar to and in other ways very different from each other. However, all of them will directly or indirectly cause the increase of the substrate surface temperature during the process of depositing microcrystalline silicon thin films, which will affect the properties of the materials with increasing time. This phenomenon is very serious for the high deposition rate of microcrystalline silicon thin films because of the high input power and the relatively small inter-electrode distance needed. Through analysis of the heating effects occurring in the process of depositing microcrystalline silicon, it is proposed that the discharge power and the heating temperature should be as low as possible, and the total gas flow rate and the inter-electrode distance should be suitable so that device-grade high quality deposition rate microcrystalline silicon thin films can be fabricated

  17. Investigation of effect of process parameters on multilayer builds by direct metal deposition

    International Nuclear Information System (INIS)

    Amine, Tarak; Newkirk, Joseph W.; Liou, Frank

    2014-01-01

    Multilayer direct laser deposition (DLD) is a fabrication process through which parts are fabricated by creating a molten pool into which metal powder is injected as. During fabrication, complex thermal activity occurs in different regions of the build; for example, newly deposited layers will reheat previously deposited layers. The objective of this study was to provide insight into the thermal activity that occurs during the DLD process. This work focused on the effect of the deposition parameters of deposited layers on the microstructure and mechanical properties of the previously deposited layers. It is important to characterize these effects in order to provide information for proper parameter selection in future DLD fabrication. Varying the parameters was shown to produce different effects on the microstructure morphology and property values, presumably resulting from in-situ quench and tempering of the steels. In general, the microstructure was secondary dendrite arm spacing. Typically, both the travel speed and laser power significantly affect the microstructure and hardness. A commercial ABAQUS/CAE software was used to model this process by developing a thermo-mechanical 3D finite element model. This work presents a 3D heat transfer model that considers the continuous addition of mass in front of a moving laser beam using ABAQUS/CAE software. The model assumes the deposit geometry appropriate to each experimental condition and calculates the temperature distribution, cooling rates and re-melted layer depth, which can affect the final microstructure. Model simulations were qualitatively compared with experimental results acquired in situ using a K-type thermocouple. - Highlights: • Direct laser deposition DLD. • Microstructure of stainless steel 316L. • Thermocouples measurement. • 3D finite element modeling

  18. Sustained Water Quality Impacts in Marine Environments Due to Mechanical Milling of Volcanic Deposits

    Science.gov (United States)

    Genareau, K. D.; Cronin, S. J.; Stewart, C.; Back, E.

    2015-12-01

    Explosive volcanic eruptions are known to be a significant geohazard, but post- or inter-eruptive processes (such as lahars, landslides, and debris avalanches) can be equally damaging to local and regional areas by remobilizing deposits. Numerous studies have found that soluble salts bound to ash grain surfaces may be quickly released into exposed waters, often lowering pH and adding trace metals with both beneficial and deleterious effects on marine flora and fauna (e.g., Fe influx initiating blooms of marine phytoplankton). Most of the cation content of pyroclastic deposits is released slowly into the environment through weathering and alteration processes. However, other pathways exist through the physical comminution of pyroclasts in fluvial and marine settings. In this case, mechanical fracturing of pyroclasts during progressive stages of disaggregation will lead to exposure of reactive particle surfaces. This study evaluates the potential, ongoing effects on water quality by experimental, mechanical milling of pyroclasts and the evaluation of released metals into exposed waters using the pyroclastic density current deposits of both the 2010 eruption of Merapi and the 2014 eruption of Kelud (Java, Indonesia), which have a bulk basaltic andesite/andesite composition (60-65 wt% SiO2). The electrical conductivity (EC) of water samples positively correlates with Ca and Sr concentrations in the case of bulk ash, whole, and crushed lapilli, but correlates with Na for the milled samples. Compared to other stages of pyroclast disaggregation, milled lapilli have the greatest effect on the concentration of alkali elements and produce a significant increase in Ca, Na, K, and Si. Mechanical milling of pyroclasts grinds down minerals and glass, resulting in an increased EC, pH, and Na concentration of exposed waters. Similar experiments are currently being conducted using basalt (50 wt% SiO2) and rhyolite (70 wt% SiO2) deposits, and these results will be presented

  19. Heat deposition on the first wall due to ICRF-induced loss of fast ions in JT-60U

    International Nuclear Information System (INIS)

    Kusama, Y.; Tobita, K.; Kimura, H.; Hamamatsu, K.; Fujii, T.; Nemoto, M.; Saigusa, M.; Moriyama, S.; Tani, K.; Koide, Y.; Sakasai, A.; Nishitani, T.; Ushigusa, K.

    1995-01-01

    In JT-60U, the heat deposition on the first wall due to the ICRF-induced loss of fast ions was investigated by changing the position of the resonance layer in the ripple-trapping region. A heat spot appears on the first wall of the same major radius as the resonance layer of the ICRF waves. The broadening of the heat spot in the major radius direction is consistent with that of the resonance layer due to the Doppler broadening. The heat spot is considered to be formed by the ICRF-induced ripple-trapped loss of fast ions. Although the total ICRF-induced loss power to the heat spot is as low as 2% of the total ICRF power, the additional heat flux will become a new issue because of the localized heat deposition on the first wall. ((orig.))

  20. Due Process Hearing Case Study

    Science.gov (United States)

    Bateman, David F.

    2009-01-01

    William is 9 years of age, residing with his parent within the boundaries of an unnamed district ("the District"). As a student with autism he is eligible for special education programming and services. There was one issue presented for this due process hearing: What was the appropriate program and placement for him for the 2008-2009 school year?…

  1. Simultaneous Co-deposition of Zn-Mg Alloy Layers on Steel Strip by PVD Process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Yeob [POSCO Technical Research Laboratories, Gwangyang (Korea, Republic of); Goodenough, Mark [Strategic Marketing, Tata Steel, Warwickshire (United Kingdom)

    2011-12-15

    This is the first release of an interim report on the development of coating technology of Zn-Mg alloy layers on steel strip by EML-PVD (electromagnetic levitation - physical vapor deposition) process in an air-to-air type continuous PVD pilot plant. It intends to introduce a basic principle of the EML-PVD process together with the high speed PVD pilot plant built in Posco. Due to the agitation effect provided by the high frequency induction coil, simultaneous evaporation of Zn and Mg from a droplet could produce alloy coating layers with Mg content of 6% to 12% depending on the composition of the droplet inside the coil. For its superior corrosion resistance, Zn-Mg alloy coated steel would be a very promising material for automotive, electrical appliances, and construction applications.

  2. Simultaneous Co-deposition of Zn-Mg Alloy Layers on Steel Strip by PVD Process

    International Nuclear Information System (INIS)

    Kim, Tae Yeob; Goodenough, Mark

    2011-01-01

    This is the first release of an interim report on the development of coating technology of Zn-Mg alloy layers on steel strip by EML-PVD (electromagnetic levitation - physical vapor deposition) process in an air-to-air type continuous PVD pilot plant. It intends to introduce a basic principle of the EML-PVD process together with the high speed PVD pilot plant built in Posco. Due to the agitation effect provided by the high frequency induction coil, simultaneous evaporation of Zn and Mg from a droplet could produce alloy coating layers with Mg content of 6% to 12% depending on the composition of the droplet inside the coil. For its superior corrosion resistance, Zn-Mg alloy coated steel would be a very promising material for automotive, electrical appliances, and construction applications

  3. Process maps for plasma spray. Part II: Deposition and properties

    International Nuclear Information System (INIS)

    XIANGYANG, JIANG; MATEJICEK, JIRI; KULKARNI, ANAND; HERMAN, HERBERT; SAMPATH, SANJAY; GILMORE, DELWYN L.; NEISER A, RICHARD Jr.

    2000-01-01

    This is the second paper of a two part series based on an integrated study carried out at the State University of New York at Stony Brook and Sandia National Laboratories. The goal of the study is the fundamental understanding of the plasma-particle interaction, droplet/substrate interaction, deposit formation dynamics and microstructure development as well as the deposit property. The outcome is science-based relationships, which can be used to link processing to performance. Molybdenum splats and coatings produced at 3 plasma conditions and three substrate temperatures were characterized. It was found that there is a strong mechanical/thermal interaction between droplet and substrate, which builds up the coatings/substrate adhesion. Hardness, thermal conductivity, and modulus increase, while oxygen content and porosity decrease with increasing particle velocity. Increasing deposition temperature resulted in dramatic improvement in coating thermal conductivity and hardness as well as increase in coating oxygen content. Indentation reveals improved fracture resistance for the coatings prepared at higher deposition temperature. Residual stress was significantly affected by deposition temperature, although not significant by particle energy within the investigated parameter range. Coatings prepared at high deposition temperature with high-energy particles suffered considerably less damage in wear tests. Possible mechanisms behind these changes are discussed within the context of relational maps which are under development

  4. Land subsidence due to groundwater pumping and recharge: considering the particle-deposition effect in ground-source heat-pump engineering

    Science.gov (United States)

    Cui, Xianze; Liu, Quansheng; Zhang, Chengyuan; Huang, Yisheng; Fan, Yong; Wang, Hongxing

    2018-01-01

    With the rapid development and use of ground-source heat-pump (GSHP) systems in China, it has become imperative to research the effects of associated long-term pumping and recharge processes on ground deformation. During groundwater GSHP operation, small particles can be transported and deposited, or they can become detached in the grain skeleton and undergo recombination, possibly causing a change in the ground structure and characteristics. This paper presents a mathematical ground-deformation model that considers particle transportation and deposition in porous media based on the geological characteristics of a dual-structure stratum in Wuhan, eastern China. Thermal effects were taken into consideration because the GSHP technology used involves a device that uses heat from a shallow layer of the ground. The results reveal that particle deposition during the long-term pumping and recharge process has had an impact on ground deformation that has significantly increased over time. In addition, there is a strong correlation between the deformation change (%) and the amount of particle deposition. The position of the maximum deformation change is also the location where most of the particles are deposited, with the deformation change being as high as 43.3%. The analyses also show that flow of groundwater can have an effect on the ground deformation process, but the effect is very weak.

  5. Land subsidence due to groundwater pumping and recharge: considering the particle-deposition effect in ground-source heat-pump engineering

    Science.gov (United States)

    Cui, Xianze; Liu, Quansheng; Zhang, Chengyuan; Huang, Yisheng; Fan, Yong; Wang, Hongxing

    2018-05-01

    With the rapid development and use of ground-source heat-pump (GSHP) systems in China, it has become imperative to research the effects of associated long-term pumping and recharge processes on ground deformation. During groundwater GSHP operation, small particles can be transported and deposited, or they can become detached in the grain skeleton and undergo recombination, possibly causing a change in the ground structure and characteristics. This paper presents a mathematical ground-deformation model that considers particle transportation and deposition in porous media based on the geological characteristics of a dual-structure stratum in Wuhan, eastern China. Thermal effects were taken into consideration because the GSHP technology used involves a device that uses heat from a shallow layer of the ground. The results reveal that particle deposition during the long-term pumping and recharge process has had an impact on ground deformation that has significantly increased over time. In addition, there is a strong correlation between the deformation change (%) and the amount of particle deposition. The position of the maximum deformation change is also the location where most of the particles are deposited, with the deformation change being as high as 43.3%. The analyses also show that flow of groundwater can have an effect on the ground deformation process, but the effect is very weak.

  6. Comparison of deposited surface area of airborne ultrafine particles generated from two welding processes.

    Science.gov (United States)

    Gomes, J F; Albuquerque, P C; Miranda, Rosa M; Santos, Telmo G; Vieira, M T

    2012-09-01

    This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers.

  7. The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

    2015-05-01

    Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films.

  8. The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Lisco, F.; Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

    2015-01-01

    Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films

  9. Solidification in direct metal deposition by LENS processing

    Science.gov (United States)

    Hofmeister, William; Griffith, Michelle

    2001-09-01

    Thermal imaging and metallographic analysis were used to study Laser Engineered Net Shaping (LENS™) processing of 316 stainless steel and H13 tool steel. The cooling rates at the solid-liquid interface were measured over a range of conduction conditions. The length scale of the molten zone controls cooling rates during solidification in direct metal deposition. In LENS processing, the molten zone ranges from 0.5 mm in length to 1.5 mm, resulting in cooling rates at the solid-liquid interface ranging from 200 6,000 Ks-1.

  10. Complex processing of antimony-mercury gold concentrates of Dzhizhikrut Deposit

    International Nuclear Information System (INIS)

    Abdusalyamova, M.N.; Gadoev, S.A.; Dreisinger, D.; Solozhenkin, P.M.

    2013-01-01

    Present article is devoted to complex processing of antimony-mercury gold concentrates of Dzhizhikrut Deposit. The purpose of research was obtaining the metallic mercury and antimony with further gold and thallium extraction.

  11. Scope and limitations of due process in administrative proceedings

    Directory of Open Access Journals (Sweden)

    Bernardo Carvajal Sánchez

    2010-12-01

    Full Text Available In order to explain in a better way the scope of Due Process in Administrative Law as a legal norm whose respect is essential to all government agencies, three points of view (formal, structural and material are proposed. Those items seem useful to understand “Administrative Due Process” in all its dimensions: as a constitutional norm developed by the enactment of laws and decrees; as a principle inspiring some conducts and new norms; and as an objective and subjective fundamental right. On the other hand, it is shown that Administrative Due Process is not an absolute rule because in some cases its full application is subject to normative relativism. Two opposite trends can be perceived at this point: in the first place, government agencies usually do not act the same way judges do, so Administrative Due Process should be distinguished from Judicial Due Process; therefore, it could actually have a more restricted scope. In the second place, some administrative authorities are nowadays playing a role more or less similar to what judges do. This means that new procedural guarantees will be claimed. In any case, admitting valid limitations to Administrative Due Process leads to the quest of the limits of these limitations. The application of the rule of Due Process cannot be totally suppressed; its scope cannot be completely reduced. This is the result of its fundamental nature as a legal norm that ensures justice and equity in all administrative procedures, and proscribes random decisions.

  12. Considerations on thermic and mechanic processes that appear when 3D printing using ABS fused deposition modelling technology

    Science.gov (United States)

    Amza, Catalin Gheorghe; Niţoi, Dan Florin

    2018-02-01

    3D printers are of recent history, but with an extremely rapid evolution both in technology and hardware involved. At present excellent performances are reached in applications such as 3D printing of various Acrylonitrile butadiene styrene (ABS) plastic parts for house building using Fused Deposition Modelling technology. Nevertheless, the thermic and mechanic processes that appear when manufacturing such plastic components are quite complex. This aspect is very important, especially when one wants to optimize the manufacturing of parts with certain geometrical complexity. The Finite Element Analysis/Modelling (FEA/FEM) is among the few methods that can study the thermic transfer processes and shape modifications that can appear due to non-seamar behavior that takes place when the ABS plastic material is cooling down. The current papers present such an analysis when simulating the deposition of several strings of materials. A thermic analysis is made followed by a study of deformations that appear when the structure cools down.

  13. Compilation of information on uncertainties involved in deposition modeling

    International Nuclear Information System (INIS)

    Lewellen, W.S.; Varma, A.K.; Sheng, Y.P.

    1985-04-01

    The current generation of dispersion models contains very simple parameterizations of deposition processes. The analysis here looks at the physical mechanisms governing these processes in an attempt to see if more valid parameterizations are available and what level of uncertainty is involved in either these simple parameterizations or any more advanced parameterization. The report is composed of three parts. The first, on dry deposition model sensitivity, provides an estimate of the uncertainty existing in current estimates of the deposition velocity due to uncertainties in independent variables such as meteorological stability, particle size, surface chemical reactivity and canopy structure. The range of uncertainty estimated for an appropriate dry deposition velocity for a plume generated by a nuclear power plant accident is three orders of magnitude. The second part discusses the uncertainties involved in precipitation scavenging rates for effluents resulting from a nuclear reactor accident. The conclusion is that major uncertainties are involved both as a result of the natural variability of the atmospheric precipitation process and due to our incomplete understanding of the underlying process. The third part involves a review of the important problems associated with modeling the interaction between the atmosphere and a forest. It gives an indication of the magnitude of the problem involved in modeling dry deposition in such environments. Separate analytics have been done for each section and are contained in the EDB

  14. Process and machinery description of equipment for deposition of canisters in medium-long deposition holes

    International Nuclear Information System (INIS)

    Kalbantner, P.

    2001-08-01

    In this report twelve methods are presented to deposit a canister with spent nuclear fuel in a horizontal hole, several canisters per hole (MLH). These methods are part of the KBS-3 system. They have been developed successively, after an analysis of weak points and strong points in previously described methods. In conformance with the guidelines for Project JADE, a choices of system has been considered during the development work. This is whether canister and bentonite buffer should be deposited 'in parts', i.e. at different occasions, but shortly after each other or 'in a package', i.e. together in a single package. The other choice in the guidelines for the JADE project, whether the canister should be placed in a radiation shield or not during transport in the secondary tunnels, was not relevant to MLR. The basic technical problem is depositing heavy objects, the canister and the buffer components, in an horizontal hole which is approximately 200 m deep. Two methods for depositing of the bentonite barrier and the canisters in separate processes have been studied. For depositing of the bentonite barrier and the canister 'in a package', four alternative techniques have been studied: a metallic sleeve around the package, a loading scoop that is rotated, a fork carriage and rails. The repeated transports in a hole, a consequence of depositing several canisters in the same hole, could lead to the rock being crushed. The mutual impact of machines, load and rock wall has therefore been particularly considered. In several methods, the use of a gangway has been proposed (steel plates or layer of ice). A failure mode and effect analysis has been performed for one of the twelve methods. When comparing with a method to deposit one canister per hole using the same technique, the need for equipment and resources is far larger for this MLH method if incidents should occur during depositing. The development work reported here has not yet yielded a definitive method for placing

  15. Hydraulic experimental investigation on spatial distribution and formation process of tsunami deposit on a slope

    Science.gov (United States)

    Harada, K.; Takahashi, T.; Yamamoto, A.; Sakuraba, M.; Nojima, K.

    2017-12-01

    An important aim of the study of tsunami deposits is to estimate the characteristics of past tsunamis from the tsunami deposits found locally. Based on the tsunami characteristics estimated from tsunami deposit, it is possible to examine tsunami risk assessment in coastal areas. It is considered that tsunami deposits are formed based on the dynamic correlation between tsunami's hydraulic values, sediment particle size, topography, etc. However, it is currently not enough to evaluate the characteristics of tsunamis from tsunami deposits. This is considered to be one of the reasons that the understanding of the formation process of tsunami deposits is not sufficiently understood. In this study, we analyze the measurement results of hydraulic experiment (Yamamoto et al., 2016) and focus on the formation process and distribution of tsunami deposits. Hydraulic experiment was conducted with two-dimensional water channel with a slope. Tsunami was inputted as a bore wave flow. The moving floor section was installed as a seabed slope connecting to shoreline and grain size distribution was set some cases. The water level was measured using ultrasonic displacement gauges, and the flow velocity was measured using propeller current meters and an electromagnetic current meter. The water level and flow velocity was measured at some points. The distribution of tsunami deposit was measured from shoreline to run-up limit on the slope. Yamamoto et al. (2016) reported the measurement results on the distribution of tsunami deposit with wave height and sand grain size. Therefore, in this study, hydraulic analysis of tsunami sediment formation process was examined based on the measurement data. Time series fluctuation of hydraulic parameters such as Froude number, Shields number, Rouse number etc. was calculated to understand on the formation process of tsunami deposit. In the front part of the tsunami, the flow velocity take strong flow from shoreline to around the middle of slope. From

  16. Modeling of the Effect of Path Planning on Thermokinetic Evolutions in Laser Powder Deposition Process

    Science.gov (United States)

    Foroozmehr, Ehsan; Kovacevic, Radovan

    2011-07-01

    A thermokinetic model coupling finite-element heat transfer with transformation kinetics is developed to determine the effect of deposition patterns on the phase-transformation kinetics of laser powder deposition (LPD) process of a hot-work tool steel. The finite-element model is used to define the temperature history of the process used in an empirical-based kinetic model to analyze the tempering effect of the heating and cooling cycles of the deposition process. An area is defined to be covered by AISI H13 on a substrate of AISI 1018 with three different deposition patterns: one section, two section, and three section. The two-section pattern divides the area of the one-section pattern into two sections, and the three-section pattern divides that area into three sections. The results show that dividing the area under deposition into smaller areas can influence the phase transformation kinetics of the process and, consequently, change the final hardness of the deposited material. The two-section pattern shows a higher average hardness than the one-section pattern, and the three-section pattern shows a fully hardened surface without significant tempered zones of low hardness. To verify the results, a microhardness test and scanning electron microscope were used.

  17. Indium oxide deposition on glass by aerosol pyrolysis (Pyrosol (R) process)

    International Nuclear Information System (INIS)

    Blandenet, G.; Lagarde, Y.; Spitz, J.

    1975-01-01

    The pyrosol (R) process involves the pyrolysis of an aerosol generated by ultrasonic nebulisation from a solution of organic or inorganic compounds. This technique was used to deposit transparent n-conducting indium oxide films on glass. The electrical and optical properties of these films were studied as a function of the deposition temperature and doping (using tin or fluorine). A deposition temperature of 480 deg C and a Sn/In ratio of about 5% gave the best results. In this case, the transmission in the visible range was 92%, the infrared reflection 84% and the electrical resistivity 1.7x10 -4 ohm.cm [fr

  18. Ti film deposition process of a plasma focus: Study by an experimental design

    Directory of Open Access Journals (Sweden)

    M. J. Inestrosa-Izurieta

    2017-10-01

    Full Text Available The plasma generated by plasma focus (PF devices have substantially different physical characteristics from another plasma, energetic ions and electrons, compared with conventional plasma devices used for plasma nanofabrication, offering new and unique opportunities in the processing and synthesis of Nanomaterials. This article presents the use of a plasma focus of tens of joules, PF-50J, for the deposition of materials sprayed from the anode by the plasma dynamics in the axial direction. This work focuses on the determination of the most significant effects of the technological parameters of the system on the obtained depositions through the use of a statistical experimental design. The results allow us to give a qualitative understanding of the Ti film deposition process in our PF device depending on four different events provoked by the plasma dynamics: i an electric erosion of the outer material of the anode; ii substrate ablation generating an interlayer; iii electron beam deposition of material from the center of the anode; iv heat load provoking clustering or even melting of the deposition surface.

  19. Effect of Source, Surfactant, and Deposition Process on Electronic Properties of Nanotube Arrays

    Directory of Open Access Journals (Sweden)

    Dheeraj Jain

    2011-01-01

    Full Text Available The electronic properties of arrays of carbon nanotubes from several different sources differing in the manufacturing process used with a variety of average properties such as length, diameter, and chirality are studied. We used several common surfactants to disperse each of these nanotubes and then deposited them on Si wafers from their aqueous solutions using dielectrophoresis. Transport measurements were performed to compare and determine the effect of different surfactants, deposition processes, and synthesis processes on nanotubes synthesized using CVD, CoMoCAT, laser ablation, and HiPCO.

  20. Process control of high rate microcrystalline silicon based solar cell deposition by optical emission spectroscopy

    International Nuclear Information System (INIS)

    Kilper, T.; Donker, M.N. van den; Carius, R.; Rech, B.; Braeuer, G.; Repmann, T.

    2008-01-01

    Silicon thin-film solar cells based on microcrystalline silicon (μc-Si:H) were prepared in a 30 x 30 cm 2 plasma-enhanced chemical vapor deposition reactor using 13.56 or 40.68 MHz plasma excitation frequency. Plasma emission was recorded by optical emission spectroscopy during μc-Si:H absorber layer deposition at deposition rates between 0.5 and 2.5 nm/s. The time course of SiH * and H β emission indicated strong drifts in the process conditions particularly at low total gas flows. By actively controlling the SiH 4 gas flow, the observed process drifts were successfully suppressed resulting in a more homogeneous i-layer crystallinity along the growth direction. In a deposition regime with efficient usage of the process gas, the μc-Si:H solar cell efficiency was enhanced from 7.9 % up to 8.8 % by applying process control

  1. Tsunami deposits

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  2. Tsunami deposits

    International Nuclear Information System (INIS)

    2013-01-01

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  3. Causal knowledge extraction by natural language processing in material science: a case study in chemical vapor deposition

    Directory of Open Access Journals (Sweden)

    Yuya Kajikawa

    2006-11-01

    Full Text Available Scientific publications written in natural language still play a central role as our knowledge source. However, due to the flood of publications, the literature survey process has become a highly time-consuming and tangled process, especially for novices of the discipline. Therefore, tools supporting the literature-survey process may help the individual scientist to explore new useful domains. Natural language processing (NLP is expected as one of the promising techniques to retrieve, abstract, and extract knowledge. In this contribution, NLP is firstly applied to the literature of chemical vapor deposition (CVD, which is a sub-discipline of materials science and is a complex and interdisciplinary field of research involving chemists, physicists, engineers, and materials scientists. Causal knowledge extraction from the literature is demonstrated using NLP.

  4. Hardness Enhancement of STS304 Deposited with Yttria Stabilized Zirconia by Aerosol Deposition Method

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Il-Ho; Park, Chun-Kil; Kim, Hyung Sun; Jeong, Dea-Yong [Inha University, Incheon (Korea, Republic of); Lee, Yong-Seok [Sodoyeon Co., Yeoju (Korea, Republic of); Kong, Young-Min [University of Ulsan, Ulsan (Korea, Republic of); Kang, Kweon Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-03-15

    To improve the surface hardness of the STS304, Yttria stabilized zirconia (YSZ) films with nano-sized grain were deposited by an aerosol-deposition (AD) method. Coating layers showed dense structure and had -5µm thickness. When 3 mol% YSZ powders with tetragonal phase were deposited on STS304 substrate, tetragonal structure was transformed to cubic structure due to the high impact energy during the AD process. At the same time, strong impact by YSZ particles allowed the austenite phase in STS304 to be transformed into martensite phase. Surface hardness measured with nano indentor showed that YSZ coated film had 11.5 GPa, which is larger value than 7 GPa of STS304.

  5. Deposition of metallic nanoparticles on carbon nanotubes via a fast evaporation process

    International Nuclear Information System (INIS)

    Ren Guoqiang; Xing Yangchuan

    2006-01-01

    A new technique was developed for the deposition of colloidal metal nanoparticles on carbon nanotubes. It involves fast evaporation of a suspension containing sonochemically functionalized carbon nanotubes and colloidal nanoparticles. It was demonstrated that metallic nanoparticles with different sizes and concentrations can be deposited on the carbon nanotubes with only a few agglomerates. The technique does not seem to be limited by what the nanoparticles are, and therefore would be applicable to the deposition of other nanoparticles on carbon nanotubes. PtPd and CoPt 3 alloy nanoparticles were used to demonstrate the deposition process. It was found that the surfactants used to disperse the nanoparticles can hinder the nanoparticle deposition. When the nanoparticles were washed with ethanol, they could be well deposited on the carbon nanotubes. The obtained carbon nanotube supported metal nanoparticles were characterized by transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and cyclic voltammetry

  6. Temperature dependence of the residual stresses and mechanical properties in TiN/CrN nano-layered coatings processed by cathodic arc deposition

    International Nuclear Information System (INIS)

    Lomello, F.; Arab Pour Yazdi; Sanchette, F.; Schuster, F.; Tabarant, M.; Billard, A.

    2014-01-01

    Nano-layered TiN-CrN coatings were synthesized by cathodic arc deposition (CAD) on M2 tool steel substrates. The aim of this study was to establish a double-correlation between the influence of the bilayer period and the deposition temperature on the resulting mechanical-tribological properties. The superlattice hardening enhancement was observed in samples deposited at different temperatures - i.e. without additional heating, 300 C and 400 C. Nonetheless, the residual compressive stresses are believed to be the responsible for reducing the hardness enhancement when the deposition temperature was increased. For instance, sample deposited without additional heating presented a hardness of 48.5 ± 1.3 GPa, while by increasing the processing temperature up to 400 C it was reduced down to 31.2 ± 4.1 GPa due to the stress relaxation. Indeed, the sample deposited at low temperature which possesses the thinnest bilayer period (13 nm) exhibited better mechanical properties. On the contrary, the role of the interfaces introduced when the period is decreased seems to rule the wear resistance. (authors)

  7. Laser vapor phase deposition of semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Karlov, N.V.; Luk' ianchuk, B.S.; Sisakian, E.V.; Shafeev, G.A.

    1987-06-01

    The pyrolytic effect of IR laser radiation is investigated with reference to the initiation and control of the vapor phase deposition of semiconductor films. By selecting the gas mixture composition and laser emission parameters, it is possible to control the deposition and crystal formation processes on the surface of semiconductors, with the main control action achieved due to the nonadiabatic kinetics of reactions in the gas phase and high temperatures in the laser heating zone. This control mechanism is demonstrated experimentally during the laser vapor deposition of germanium and silicon films from tetrachlorides on single-crystal Si and Ge substrates. 5 references.

  8. Apparatus and process for deposition of hard carbon films

    Science.gov (United States)

    Nyaiesh, Ali R.; Garwin, Edward L.

    1989-01-03

    A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.

  9. Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

    International Nuclear Information System (INIS)

    Rao, D. Srinivasa; Valleti, Krishna; Joshi, S. V.; Janardhan, G. Ranga

    2011-01-01

    The physical and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented.

  10. Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hafley, Robert A. (Inventor); Martin, Richard E. (Inventor); Hofmeister, William H. (Inventor)

    2013-01-01

    A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

  11. Feature scale modeling for etching and deposition processes in semiconductor manufacturing

    International Nuclear Information System (INIS)

    Pyka, W.

    2000-04-01

    Simulation of etching and deposition processes as well as three-dimensional geometry generation are important issues in state of the art TCAD applications. Three-dimensional effects are gaining importance for semiconductor devices and for their interconnects. Therefore a strictly physically based simulation of their topography is required. Accurate investigation of single etching and deposition processes has become equally important as process integration. Within this context several aspects of three-dimensional topography simulation have been covered by this thesis and new and interesting results have been achieved in various areas. The algorithmic core of the cell-based structuring element surface propagation method has been optimized and has been eliminated from its position as factor which predominantly determines the required CPU time. In parallel with investigated optimization techniques and required by various process models, the implementation of the surface normal calculation and the special handling of voids and unconnected parts of the geometry has been completed in three dimensions. A process-step-based solid modeling tool which incorporates layout data as well as aerial image simulation has been supplied. It can be coupled with the topography simulation and includes simple geometrically based models for CMP and oxidation. In the presented combination, the tool makes use of the design information stored in the layout file, combines it with the manufacturing recipe, and hence is extremely helpful for the automatic generation of three-dimensional structures. Its usefulness has been proven with several interconnect examples. Regarding topography models, resist development not only turned out to be very helpful for predicting exposed and etched resist profiles within a rigorous lithography simulation, but, by means of benchmark examples, also demonstrated the extraordinary stability of the proposed cellular surface movement algorithm. With respect to

  12. An Experimental Study on Slurry Erosion Resistance of Single and Multilayered Deposits of Ni-WC Produced by Laser-Based Powder Deposition Process

    Science.gov (United States)

    Balu, Prabu; Hamid, Syed; Kovacevic, Radovan

    2013-11-01

    Single and multilayered deposits containing different mass fractions of tungsten carbide (WC) in nickel (Ni)-matrix (NT-20, NT-60, NT-80) are deposited on a AISI 4140 steel substrate using a laser-based powder deposition process. The transverse cross section of the coupons reveals that the higher the mass fraction of WC in Ni-matrix leads to a more uniform distribution through Ni-matrix. The slurry erosion resistance of the fabricated coupons is tested at three different impingement angles using an abrasive water jet cutting machine, which is quantified based on the erosion rate. The top layer of a multilayered deposit (i.e., NT-60 in a two-layer NT-60 over NT-20 deposit) exhibits better erosion resistance at all three tested impingement angles when compared to a single-layer (NT-60) deposit. A definite increase in the erosion resistance is noted with an addition of nano-size WC particles. The relationship between the different mass fractions of reinforcement (WC) in the deposited composite material (Ni-WC) and their corresponding matrix (Ni) hardness on the erosion rate is studied. The eroded surface is analyzed in the light of a three-dimensional (3-D) profilometer and a scanning electron microscope (SEM). The results show that a volume fraction of approximately 62% of WC with a Ni-matrix hardness of 540 HV resulting in the gouging out of WC from the Ni-matrix by the action of slurry. It is concluded that the slurry erosion resistance of the AISI 4140 steel can be significantly enhanced by introducing single and multilayered deposits of Ni-WC composite material fabricated by the laser-based powder deposition process.

  13. Reduced thermal budget processing of Y-Ba-Cu-O films by rapid isothermal processing assisted metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Singh, R.; Sinha, S.; Hsu, N.J.; Ng, J.T.C.; Chou, P.; Thakur, R.P.S.; Narayan, J.

    1991-01-01

    Metalorganic chemical vapor deposition (MOCVD) has the potential of emerging as a viable technique to fabricate ribbons, tapes, coated wires, and the deposition of films of high-temperature superconductors, and related materials. As a reduced thermal budget processing technique, rapid isothermal processing (RIP) based on incoherent radiation as the source of energy can be usefully coupled to conventional MOCVD. In this paper we report on the deposition and characterization of high quality superconducting thin films of Y-Ba-Cu-O (YBCO) on yttrium stabilized zirconia substrates by RIP assisted MOCVD. Using O 2 gas as the source of oxygen, YBCO films deposited initially at 600 degree C for 1 min and at 745 degree C for 25 min followed by deposition at 780 degree C for 45 s are primarily c-axis oriented and zero resistance is observed at 89--90 K. The zero magnetic field current density at 53 and 77 K are 1.2x10 6 and 3x10 5 A/cm 2 , respectively. By using a mixture of N 2 O and O 2 as the oxygen source substrate temperature was further reduced in the deposition of YBCO films. The films deposited initially at 600 degree C for 1 min and than at 720 degree C for 30 min are c-axis oriented and with zero resistance being observed at 91 K. The zero magnetic field current densities at 53 and 77 K are 3.4x10 6 and 1.2x10 6 A/cm 2 , respectively. To the best of our knowledge this is the highest value of critical current density, J c for films deposited by MOCVD at a substrate temperature as low as 720 degree C. It is envisioned that high energy photons from the incoherent light source and the use of a mixture of N 2 O and O 2 as the oxygen source, assist chemical reactions and lower overall thermal budget for processing of these films

  14. Improvement of a microwave ECR plasma source for the plasma immersion ion implantation and deposition process

    International Nuclear Information System (INIS)

    Wu Hongchen; Zhang Huafang; Peng Liping; Jiang Yanli; Ma Guojia

    2004-01-01

    The Plasma Immersion Ion Implantation and Deposition (PIII and D) process has many advantages over the pure plasma immersion ion implantation or deposition. It can compensate for or eliminate the disadvantages of the shallow modification layer (for PIII) and increase the bond strength of the coating (of deposition). For this purpose, a new type of microwave plasma source used in the PIII and D process was developed, composed of a vacuum bend wave guide and a special magnetic circuit, so that the coupling window was protected from being deposited with a coating and bombarded by high-energy particles. So the life of the window is increased. To enhance the bonding between the coating and substrate a new biasing voltage is applied to the work piece so that the implantation and deposition (or hybrid process) can be completed in one vacuum cycle

  15. Reactive physical vapor deposition of TixAlyN: Integrated plasma-surface modeling characterization

    International Nuclear Information System (INIS)

    Zhang Da; Schaeffer, J.K.

    2004-01-01

    Reactive physical vapor deposition (RPVD) has been widely applied in the microelectronic industry for producing thin films. Fundamental understanding of RPVD mechanisms is needed for successful process development due to the high sensitivity of film properties on process conditions. An integrated plasma equipment-target nitridation modeling infrastructure for RPVD has therefore been developed to provide mechanistic insights and assist optimal process design. The target nitridation model computes target nitride coverage based on self-consistently derived plasma characteristics from the plasma equipment model; target sputter yields needed in the plasma equipment model are also self-consistently derived taking into account the yield-suppressing effect from nitridation. The integrated modeling infrastructure has been applied to investigating RPVD processing with a Ti 0.8 Al 0.2 compound target and an Ar/N 2 gas supply. It has been found that the process produces athermal metal neutrals as the primary deposition precursor. The metal stoichiometry in the deposited film is close to the target composition due to the predominance of athermal species in the flux that reaches the substrate. Correlations between process parameters (N 2 flow, target power), plasma characteristics, surface conditions, and deposition kinetics have been studied with the model. The deposition process is characterized by two regimes when the N 2 flow rate is varied. When N 2 is dilute relative to argon, target nitride coverage increases rapidly with increasing N 2 flow. The sputter yield and deposition rate consequently decrease. For less dilute N 2 mixtures, the sputter yield and deposition rate are stable due to the saturation of target nitridation. With increasing target power, the electron density increases nearly linearly while the variation of N generation is much smaller. Target nitridation and its suppression of the sputter yield saturate at high N 2 flow rendering these parameters

  16. Application of laser assisted cold spraying process for metal deposition

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-02-01

    Full Text Available Laser assisted cold spraying (LACS) process is a hybrid technique that uses laser and cold spray to deposit solid powders on metal substrates. For bonding to occur, the particle velocities must be supersonic which are achieved by entraining...

  17. Numerical experiment on tsunami deposit distribution process by using tsunami sediment transport model in historical tsunami event of megathrust Nankai trough earthquake

    Science.gov (United States)

    Imai, K.; Sugawara, D.; Takahashi, T.

    2017-12-01

    A large flow caused by tsunami transports sediments from beach and forms tsunami deposits in land and coastal lakes. A tsunami deposit has been found in their undisturbed on coastal lakes especially. Okamura & Matsuoka (2012) found some tsunami deposits in the field survey of coastal lakes facing to the Nankai trough, and tsunami deposits due to the past eight Nankai Trough megathrust earthquakes they identified. The environment in coastal lakes is stably calm and suitable for tsunami deposits preservation compared to other topographical conditions such as plains. Therefore, there is a possibility that the recurrence interval of megathrust earthquakes and tsunamis will be discussed with high resolution. In addition, it has been pointed out that small events that cannot be detected in plains could be separated finely (Sawai, 2012). Various aspects of past tsunami is expected to be elucidated, in consideration of topographical conditions of coastal lakes by using the relationship between the erosion-and-sedimentation process of the lake bottom and the external force of tsunami. In this research, numerical examination based on tsunami sediment transport model (Takahashi et al., 1999) was carried out on the site Ryujin-ike pond of Ohita, Japan where tsunami deposit was identified, and deposit migration analysis was conducted on the tsunami deposit distribution process of historical Nankai Trough earthquakes. Furthermore, examination of tsunami source conditions is possibly investigated by comparison studies of the observed data and the computation of tsunami deposit distribution. It is difficult to clarify details of tsunami source from indistinct information of paleogeographical conditions. However, this result shows that it can be used as a constraint condition of the tsunami source scale by combining tsunami deposit distribution in lakes with computation data.

  18. Processes of preparation, deposition and analysis of thermionic emissive substances

    International Nuclear Information System (INIS)

    Romao, B.M. Verdelli; Muraro Junior, A.; Tessaroto, L.A.B.; Takahashi, J.

    1992-09-01

    This paper shows the results of the optimization of the process of preparation and deposition of thermionic emissive substances that are used in the oxide-cathodes which are utilized in the gun of the IEAv linear electron accelerator. (author). 5 refs., 5 figs

  19. Thermokinetic Modeling of Phase Transformation in the Laser Powder Deposition Process

    Science.gov (United States)

    Foroozmehr, Ehsan; Kovacevic, Radovan

    2009-08-01

    A finite element model coupled with a thermokinetic model is developed to predict the phase transformation of the laser deposition of AISI 4140 on a substrate with the same material. Four different deposition patterns, long-bead, short-bead, spiral-in, and spiral-out, are used to cover a similar area. Using a finite element model, the temperature history of the laser powder deposition (LPD) process is determined. The martensite transformation as well as martensite tempering is considered to calculate the final fraction of martensite, ferrite, cementite, ɛ-carbide, and retained austenite. Comparing the surface hardness topography of different patterns reveals that path planning is a critical parameter in laser surface modification. The predicted results are in a close agreement with the experimental results.

  20. Chromium carbide thin films deposited by ultra-short pulse laser deposition

    International Nuclear Information System (INIS)

    Teghil, R.; Santagata, A.; De Bonis, A.; Galasso, A.; Villani, P.

    2009-01-01

    Pulsed laser deposition performed by a laser with a pulse duration of 250 fs has been used to deposit films from a Cr 3 C 2 target. Due to the different processes involved in the laser ablation when it is performed by an ultra-short pulse source instead of a conventional short pulse one, it has been possible to obtain in vacuum films containing only one type of carbide, Cr 3 C 2 , as shown by X-ray photoelectron spectroscopy. On the other hand, Cr 3 C 2 is not the only component of the films, since a large amount of amorphous carbon is also present. The films, deposited at room temperature, are amorphous and seem to be formed by the coalescence of a large number of particles with nanometric size. The film composition can be explained in terms of thermal evaporation from particles ejected from the target.

  1. Procedural Due Process and Fairness in Student Discipline. A Legal Memorandum.

    Science.gov (United States)

    Johnson, T. Page

    When the Supreme Court decided that the Constitution requires public school principals to follow procedural due process in suspension and expulsion cases, the Justices recognized a link between procedural due process and the fairness of effective discipline. This report reviews the constitutional due process required when public school officials…

  2. The erosion performance of cold spray deposited metal matrix composite coatings with subsequent friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Peat, Tom, E-mail: tompeat12@gmail.com [Department of Mechanical & Aerospace Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ (United Kingdom); Galloway, Alexander; Toumpis, Athanasios [Department of Mechanical & Aerospace Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ (United Kingdom); McNutt, Philip [TWI Ltd., Granta Park, Cambridge CB21 6AL (United Kingdom); Iqbal, Naveed [TWI Technology Centre, Wallis Way, Catcliff, Rotherham, S60 5TZ (United Kingdom)

    2017-02-28

    Highlights: • WC-CoCr, Cr{sub 3}C{sub 2}-NiCr and Al{sub 2}O{sub 3} coatings were cold spray deposited on AA5083 and friction stir processed. • The SprayStirred WC-CoCr demonstrated a hardness increase of 100% over the cold sprayed coating. • As-deposited and SprayStirred coatings were examined under slurry erosion test conditions. • Mass and volume loss was measured following 20-min exposure to the slurry. • The WC-CoCr and Al2O3 demonstrated a reduction in volume loss of approx. 40% over the cold sprayed coating. - Abstract: This study forms an initial investigation into the development of SprayStir, an innovative processing technique for generating erosion resistant surface layers on a chosen substrate material. Tungsten carbide – cobalt chromium, chromium carbide – nickel chromium and aluminium oxide coatings were successfully cold spray deposited on AA5083 grade aluminium. In order to improve the deposition efficiency of the cold spray process, coatings were co-deposited with powdered AA5083 using a twin powder feed system that resulted in thick (>300 μm) composite coatings. The deposited coatings were subsequently friction stir processed to embed the particles in the substrate in order to generate a metal matrix composite (MMC) surface layer. The primary aim of this investigation was to examine the erosion performance of the SprayStirred surfaces and demonstrate the benefits of this novel process as a surface engineering technique. Volumetric analysis of the SprayStirred surfaces highlighted a drop of approx. 40% in the level of material loss when compared with the cold spray deposited coating prior to friction stir processing. Micro-hardness testing revealed that in the case of WC-CoCr reinforced coating, the hardness of the SprayStirred material exhibits an increase of approx. 540% over the unaltered substrate and 120% over the as-deposited composite coating. Microstructural examination demonstrated that the increase in the hardness of the

  3. AFT Chief Promises Due-Process Reform

    Science.gov (United States)

    Sawchuk, Stephen

    2010-01-01

    The president of the American Federation of Teachers (AFT), Randi Weingarten, is putting the sensitive issue of due process on the education reform table, with a pledge to work with districts to streamline the often-cumbersome procedures for dismissing teachers who fail to improve their performance after receiving help and support. She has also…

  4. The fate of SOC during the processes of water erosion and subsequent deposition: a field study.

    Science.gov (United States)

    van Hemelryck, H.; Govers, G.; van Oost, K.; Merckx, R.

    2009-04-01

    Globally soils are the largest terrestrial pool of carbon (C). A relatively small increase or decrease in soil carbon content due to changes in land use or management practices could therefore result in a significant net exchange of C between the soil C reservoir and the atmosphere. As such, the geomorphic processes of water and tillage erosion have been identified to significantly impact on this large pool of soil organic carbon (SOC). Soil erosion, transport and deposition not only result in redistribution of sediments and associated carbon within a landscape, but also affect the exchange of C between the pedosphere and the atmosphere. The direction and magnitude of an erosion-induced change in the global C balance is however a topic of much debate as opposing processes interact: i) At eroding sites a net uptake of C could be the result of reduced respiration rates and continued inputs of newly produced carbon. ii) Colluvial deposition of eroded sediment and SOC leads to the burial of the original topsoil and this may constrain the decomposition of its containing SOC. iii) Eroded sediment could be transported to distal depositional environments or fluvial systems where it will either be conserved or become rapidly mineralized. iv) Increased emission of CO2 due to erosion may result from the disruptive energy of erosive forces causing the breakdown of aggregates and exposing previously protected SOC to microbial decomposition. The above-mentioned processes show a large spatial and temporal variability and assessing their impact requires an integrated modeling approach. However uncertainties about the basic processes that accompany SOC displacement are still large. This study focuses on one of these large information gaps: the fate of eroded and subsequently deposited SOC. A preceding experimental study (Van Hemelryck et al., 2008) was used to identify controlling factors (erosional intensity, changes in soil structure,…). However this experimental research

  5. PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS

    Science.gov (United States)

    Carter, J.M.; Kamen, M.D.

    1958-10-14

    A process is presented for recovering uranium values from UCl/sub 4/ deposits formed on calutrons. Such deposits are removed from the calutron parts by an aqueous wash solution which then contains the uranium values in addition to the following impurities: Ni, Cu, Fe, and Cr. This impurity bearing wash solution is treated with an oxidizing agent, and the oxidized solution is then treated with ammonia in order to precipitate the uranium as ammonium diuranate. The metal impurities of iron and chromium, which form insoluble hydroxides, are precipitated along with the uranium values. The precipitate is separated from the solution, dissolved in acid, and the solution again treated with ammonia and ammonium carbonate, which results in the precipitation of the metal impurities as hydroxides while the uranium values remain in solution.

  6. The study on microb and organic metallogenetic process of the interlayer oxidized zone uranium deposit. A case study of the Shihongtan uranium deposit in Turpan-Hami basin

    International Nuclear Information System (INIS)

    Qiao Haiming; Shang Gaofeng

    2010-01-01

    Microbial and organic process internationally leads the field in the study of metallogenetic process presently. Focusing on Shi Hongtan uranium deposit, a typical interlayer oxidized zone sandstone-type deposit, this paper analyzes the geochemical characteristics of microb and organic matter in the deposit, and explores the interaction of microb and organic matter. It considers that the anaerobic bacterium actively takes part in the formation of the interlayer oxidized zone, as well as the mobilization and migration of uranium. In the redox (oxidation-reduction) transition zone, sulphate-reducing bacteria reduced sulphate to stink damp, lowing Eh and acidifying pH in the groundwater, which leads to reducing and absorbing of uranium, by using light hydrocarbon which is the product of the biochemical process of organism and the soluble organic matter as the source of carbon. The interaction of microb and organic matter controls the metallogenetic process of uranium in the deposit. (authors)

  7. Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

    Directory of Open Access Journals (Sweden)

    Brett B. Lewis

    2015-04-01

    Full Text Available Platinum–carbon nanostructures deposited via electron beam induced deposition from MeCpPt(IVMe3 are purified during a post-deposition electron exposure treatment in a localized oxygen ambient at room temperature. Time-dependent studies demonstrate that the process occurs from the top–down. Electron beam energy and current studies demonstrate that the process is controlled by a confluence of the electron energy loss and oxygen concentration. Furthermore, the experimental results are modeled as a 2nd order reaction which is dependent on both the electron energy loss density and the oxygen concentration. In addition to purification, the post-deposition electron stimulated oxygen purification process enhances the resolution of the EBID process due to the isotropic carbon removal from the as-deposited materials which produces high-fidelity shape retention.

  8. Corrosion processes of physical vapor deposition-coated metallic implants.

    Science.gov (United States)

    Antunes, Renato Altobelli; de Oliveira, Mara Cristina Lopes

    2009-01-01

    Protecting metallic implants from the harsh environment of physiological fluids is essential to guaranteeing successful long-term use in a patient's body. Chemical degradation may lead to the failure of an implant device in two different ways. First, metal ions may cause inflammatory reactions in the tissues surrounding the implant and, in extreme cases, these reactions may inflict acute pain on the patient and lead to loosening of the device. Therefore, increasing wear strength is beneficial to the performance of the metallic implant. Second, localized corrosion processes contribute to the nucleation of fatigue cracks, and corrosion fatigue is the main reason for the mechanical failure of metallic implants. Common biomedical alloys such as stainless steel, cobalt-chrome alloys, and titanium alloys are prone to at least one of these problems. Vapor-deposited hard coatings act directly to improve corrosion, wear, and fatigue resistances of metallic materials. The effectiveness of the corrosion protection is strongly related to the structure of the physical vapor deposition layer. The aim of this paper is to present a comprehensive review of the correlation between the structure of physical vapor deposition layers and the corrosion properties of metallic implants.

  9. Thermal analysis of fused deposition modeling process using infrared thermography imaging and finite element modeling

    Science.gov (United States)

    Zhou, Xunfei; Hsieh, Sheng-Jen

    2017-05-01

    After years of development, Fused Deposition Modeling (FDM) has become the most popular technique in commercial 3D printing due to its cost effectiveness and easy-to-operate fabrication process. Mechanical strength and dimensional accuracy are two of the most important factors for reliability of FDM products. However, the solid-liquid-solid state changes of material in the FDM process make it difficult to monitor and model. In this paper, an experimental model was developed to apply cost-effective infrared thermography imaging method to acquire temperature history of filaments at the interface and their corresponding cooling mechanism. A three-dimensional finite element model was constructed to simulate the same process using element "birth and death" feature and validated with the thermal response from the experimental model. In 6 of 9 experimental conditions, a maximum of 13% difference existed between the experimental and numerical models. This work suggests that numerical modeling of FDM process is reliable and can facilitate better understanding of bead spreading and road-to-road bonding mechanics during fabrication.

  10. Rapid processing method for solution deposited YBa2Cu3O7-δ thin films

    International Nuclear Information System (INIS)

    Dawley, J.T.; Clem, P.G.; Boyle, T.J.; Ottley, L.M.; Overmyer, D.L.; Siegal, M.P.

    2004-01-01

    YBa 2 Cu 3 O 7-δ (YBCO) films, deposited on buffered metal substrates, are the primary candidate for second-generation superconducting (SC) wires, with applications including expanded power grid transmission capability, compact motors, and enhanced sensitivity magnetic resonance imaging. Feasibility of manufacturing such superconducting wires is dependent on high processing speed, often a limitation of vapor and solution-based YBCO deposition processes. In this work, YBCO films were fabricated via a new diethanolamine-modified trifluoroacetic film solution deposition method. Modifying the copper chemistry of the YBCO precursor solution with diethanolamine enables a hundredfold decrease in the organic pyrolysis time required for MA/cm 2 current density (J c ) YBCO films, from multiple hours to ∼20 s in atmospheric pressure air. High quality, ∼0.2 μm thick YBCO films with J c (77 K) values ≥2 MA/cm 2 at 77 K are routinely crystallized from these rapidly pyrolyzed films deposited on LaAlO 3 . This process has also enabled J c (77 K)=1.1 MA/cm 2 YBCO films via 90 m/h dip-coating on Oak Ridge National Laboratory RABiTS textured metal tape substrates. This new YBCO solution deposition method suggests a route toward inexpensive and commercializable ∼$10/kA m solution deposited YBCO coated conductor wires

  11. Implementation of new integrated evaporation equipment for the preparation of 238U targets and improvement of the deposition process

    Science.gov (United States)

    Vanleeuw, D.; Lewis, D.; Moens, A.; Sibbens, G.; Wiss, T.

    2018-05-01

    Measurement of neutron cross section data is a core activity of the JRC-Directorate G for Nuclear Safety and Security in Geel. After a period of reduced activity and in line with a renewed interest for nuclear data required for GenIV reactors and waste minimization, the demand for high quality actinide targets increased. Physical vapour deposition by thermal evaporation is a key technique to prepare homogeneous thin actinide layers, but due to ageing effects the earlier in-house developed equipment can no longer provide the required quality. Because of a current lack of experience and human resources cooperation with private companies is required for the development of new deposition equipment directly integrated in a glove box. In this paper we describe the design, implementation and validation of the first commercial actinide evaporator in a glove box as well as the optimization of the deposition process. Highly enriched 238U3O8 was converted to 238UF4 powder and several deposition runs were performed on different substrates. The deposition parameters were varied and defined in order to guarantee physical and chemical stable homogeneous UF4 layers, even on polished substrates which was not longer feasible with the older equipment. The stability problem is discussed in view of the thin layer growth by physical vapour deposition and the influence of the deposition parameters on the layer quality. The deposits were characterized for the total mass by means of substitution weighing and for the areal density of 238U by means of alpha particle counting and thermal ionization mass spectrometry (TIMS). The quality of the layer was visually evaluated and by means of stereo microscopy and auto radiography.

  12. Evaluation of Mineral Deposits Along the Little Wind River, Riverton, WY, Processing Site

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Sam [Navarro Research and Engineering, Oak Ridge, TN (United States); Dam, Wiliam [US Department of Energy, Washington, DC (United States). Office of Legacy Management

    2014-12-01

    In 2012, the U.S.Department of Energy (DOE) began reassessing the former Riverton, Wyoming, Processing Site area for potential contaminant sources impacting groundwater. A flood in 2010 along the Little Wind River resulted in increases in groundwater contamination (DOE 2013).This investigation is a small part of continued efforts by DOE and other stakeholders to update human health and ecological risk assessments, to make a comprehensive examination of all exposure pathways to ensure that the site remains protective through established institutional controls. During field inspections at the Riverton Site in 2013, a white evaporitic mineral deposit was identified along the bank of the Little Wind River within the discharge zone of the groundwater contamination plume. In December 2013, Savannah River National Laboratory (SRNL) personnel collected a sample for analysis by X-ray fluorescence (Figure 1 shows the type of material sampled). The sample had a uranium concentration of approximately 64 to 73 parts per million. Although the uranium in this mineral deposit is within the expected range for evaporatic minerals in the western United States (SRNL 2014), DOE determined that additional assessment of the mineral deposit was warranted. In response to the initial collection and analysis of a sample of the mineral deposit, DOE developed a work plan (Work Plan to Sample Mineral Deposits Along the Little Wind River, Riverton, Wyoming, Processing Site [DOE 2014]) to further define the extent of these mineral deposits and the concentration of the associated contaminants (Appendix A). The work plan addressed field reconnaissance, mapping, sampling, and the assessment of risk associated with the mineral deposits adjacent to the Little Wind River.

  13. Superhydrophobic nanostructured ZnO thin films on aluminum alloy substrates by electrophoretic deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Sarkar, D.K., E-mail: dsarkar@uqac.ca; Chen, X-Grant

    2015-02-01

    Graphical abstract: - Highlights: • Fabrication of superhydrophobic ZnO thin films surfaces by electrophoretic deposition process on aluminum substrates. • Effect of bath temperature on the physical and superhydrophobic properties of thin films. • The water contact angle of 155° ± 3 with roll off property has been observed on the film that was grown at bath temperatures of 50 °C. • The activation energy for electrophoretic deposition of SA-functionalized ZnO nanoparticle is calculated to be 0.50 eV. - Abstract: Superhydrophobic thin films have been fabricated on aluminum alloy substrates by electrophoretic deposition (EPD) process using stearic acid (SA) functionalized zinc oxide (ZnO) nanoparticles suspension in alcohols at varying bath temperatures. The deposited thin films have been characterized using both X-ray diffraction (XRD) and infrared (IR) spectroscopy and it is found that the films contain low surface energy zinc stearate and ZnO nanoparticles. It is also observed that the atomic percentage of Zn and O, roughness and water contact angle of the thin films increase with the increase of the deposited bath temperature. Furthermore, the thin film deposited at 50 °C, having a roughness of 4.54 ± 0.23 μm, shows superhydrophobic properties providing a water contact angle of 155 ± 3° with rolling off properties. Also, the activation energy of electrophoretic deposition of stearic-acid-functionalized ZnO nanoparticles is calculated to be 0.5 eV.

  14. THE ROLE OF CRYOGENIC PROCESSES IN THE FORMATION OF LOESS DEPOSITS

    Directory of Open Access Journals (Sweden)

    Vyacheslav N. Konishchev

    2015-01-01

    Full Text Available The paper describes a new approach to the analysis of the genetic nature of mineral substances in loess deposits. In permafrost under the influence of multiple alternate freezing and thawing in dispersed deposits, quartz particles accumulate the 0.05-0.01 mm fraction, while feldspars are crushed to a coarse fraction of 0.1-0.05 mm. In dispersed sediments formed in temperate and warm climatic zones, the granulometric spectrum of quartz and feldspar has the opposite pattern. The proposed methodology is based on a differential analysis of the distribution of these minerals by the granulometric spectrum. We have proposed two criteria - the coefficient of cryogenic contrast (CCC and the coefficient of distribution of heavy minerals, which allow determination of the degree of participation of cryogenic processes in the formation of loess sediments and processes of aeolian or water sedimentation.

  15. Pulsed laser deposition of the lysozyme protein: an unexpected “Inverse MAPLE” process

    DEFF Research Database (Denmark)

    Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

    2012-01-01

    Films of organic materials are commonly deposited by laser assisted methods, such as MAPLE (matrix-assisted pulsed laser evaporation), where a few percent of the film material in the target is protected by a light-absorbing volatile matrix. Another possibility is to irradiate the dry organic...... the ejection and deposition of lysozyme. This can be called an “inverse MAPLE” process, since the ratio of “matrix” to film material in the target is 10:90, which is inverse of the typical MAPLE process where the film material is dissolved in the matrix down to several wt.%. Lysozyme is a well-known protein...

  16. Measures for waste water management from recovery processing of Zhushanxia uranium deposit

    International Nuclear Information System (INIS)

    Liu Yaochi; Xu Lechang

    2000-01-01

    Measures for waste water management from recovery processing of Zhushanxia uranium deposit of Wengyuan Mine is analyzed, which include improving process flow, recycling process water used in uranium mill as much as possible and choosing a suitable disposing system. All these can decrease the amount of waste water, and also reduce costs of disposing waste water and harm to environment

  17. Low-temperature processed ZnO and CdS photodetectors deposited by pulsed laser deposition

    International Nuclear Information System (INIS)

    Hernandez-Como, N; Moreno, S; Mejia, I; Quevedo-Lopez, M A

    2014-01-01

    UV-VIS photodetectors using an interdigital configuration, with zinc oxide (ZnO) and cadmium sulfide (CdS) semiconductors deposited by pulsed laser deposition, were fabricated with a maximum processing temperature of 100 °C. Without any further post-growth annealing, the photodetectors are compatible with flexible and transparent substrates. Aluminum (Al) and indium tin oxide (ITO) were investigated as contacts. Focusing on underwater communications, the impact of metal contact (ITO versus Al) was investigated to determine the maximum responsivity using a laser with a 405 nm wavelength. As expected, the responsivity increases for reduced metal finger separation. This is a consequence of reduced carrier transit time for shorter finger separation. For ITO, the highest responsivities for both films (ZnO and CdS) were ∼3 A W −1 at 5 V. On the other hand, for Al contacts, the maximum responsivities at 5 V were ∼0.1 A W −1 and 0.7 A W −1 for CdS and ZnO, respectively. (paper)

  18. The versatility of hot-filament activated chemical vapor deposition

    International Nuclear Information System (INIS)

    Schaefer, Lothar; Hoefer, Markus; Kroeger, Roland

    2006-01-01

    In the field of activated chemical vapor deposition (CVD) of polycrystalline diamond films, hot-filament activation (HF-CVD) is widely used for applications where large deposition areas are needed or three-dimensional substrates have to be coated. We have developed processes for the deposition of conductive, boron-doped diamond films as well as for tribological crystalline diamond coatings on deposition areas up to 50 cm x 100 cm. Such multi-filament processes are used to produce diamond electrodes for advanced electrochemical processes or large batches of diamond-coated tools and parts, respectively. These processes demonstrate the high degree of uniformity and reproducibility of hot-filament CVD. The usability of hot-filament CVD for diamond deposition on three-dimensional substrates is well known for CVD diamond shaft tools. We also develop interior diamond coatings for drawing dies, nozzles, and thread guides. Hot-filament CVD also enables the deposition of diamond film modifications with tailored properties. In order to adjust the surface topography to specific applications, we apply processes for smooth, fine-grained or textured diamond films for cutting tools and tribological applications. Rough diamond is employed for grinding applications. Multilayers of fine-grained and coarse-grained diamond have been developed, showing increased shock resistance due to reduced crack propagation. Hot-filament CVD is also used for in situ deposition of carbide coatings and diamond-carbide composites, and the deposition of non-diamond, silicon-based films. These coatings are suitable as diffusion barriers and are also applied for adhesion and stress engineering and for semiconductor applications, respectively

  19. Fat, oil and grease deposits in sewers: characterisation of deposits and formation mechanisms.

    Science.gov (United States)

    Williams, J B; Clarkson, C; Mant, C; Drinkwater, A; May, E

    2012-12-01

    Fat, oil and grease deposits (FOG) in sewers are a major problem and can cause sewer overflows, resulting in environmental damage and health risks. Often simplistically portrayed as cooling of fats, recent research has suggested that saponification may be involved in FOG formation. However there are still questions about the mechanisms effecting transformations in sewers and the role and source of metal cations involved in saponification. This study characterises FOG deposits from pumping stations, sewers and sewage works from different water hardness zones across the UK. The sites all had previous problems with FOG and most catchments contained catering and food preparation establishments. The FOG deposits were highly variable with moisture content ranging from 15 to 95% and oil content from 0 to 548 mg/g. Generally the pumping stations had lower moisture content and higher fat content, followed by the sewers then the sewage works. The water in contact with the FOG had high levels of oil (mean of about 800 mg/L) and this may indicate poor kitchen FOG management practices. FOG fatty acid profiles showed a transformation from unsaturated to saturated forms compared to typical cooking oils. This seems to relate to ageing in the sewer network or the mechanism of formation, as samples from pumping stations had higher proportions of C18:1 compared to C16. This may be due to microbial transformations by bacteria such as Clostridium sp. in a similar process to adipocere formation. There was an association between water hardness and increased Ca levels in FOG along with harder deposits and higher melting points. A link between FOG properties and water hardness has not been previously reported for field samples. This may also be due to microbial processes, such as biocalcification. By developing the understanding of these mechanisms it may be possible to more effectively control FOG deposits, especially when combined with promotion of behavioural change. Copyright © 2012

  20. The due diligence process for acquiring and building power plants

    International Nuclear Information System (INIS)

    Vallen, M.A.; Bullinger, C.D.

    1999-01-01

    The restructuring of the electric generating business is continuing at a torrid pace. New auctions of generation portfolios are initiated almost monthly, and announcements of new development projects arrive almost daily. It has become imperative, then, that participants in both acquisitions and development projects become conversant with the necessary due diligence process, a complex and critical task that can mean the difference between success and failure. A thorough due diligence process allows bidder/developers to uncover value and quantify liabilities before bidding/building, translating into the best analysis possible and resulting in a winning investment decision. This article describes the process by which buyers and developers approach and manage the due diligence process as a key step in making their investment decision

  1. Microstructural Effects and Properties of Non-line-of-Sight Coating Processing via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan J.; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2017-08-01

    Plasma spray-physical vapor deposition (PS-PVD) is a unique processing method that bridges the gap between conventional thermal spray and vapor phase methods, and enables highly tailorable coatings composed of a variety of materials in thin, dense layers or columnar microstructures with modification of the processing conditions. The strengths of this processing technique are material and microstructural flexibility, deposition speed, and potential for non-line-of-sight (NLOS) capability by vaporization of the feedstock material. The NLOS capability of PS-PVD is investigated here using yttria-stabilized zirconia and gadolinium zirconate, which are materials of interest for turbine engine applications. PS-PVD coatings were applied to static cylindrical substrates approximately 6-19 mm in diameter to study the coating morphology as a function of angle. In addition, coatings were deposited on flat substrates under various impingement configurations. Impingement angle had significant effects on the deposition mode, and microscopy of coatings indicated that there was a shift in the deposition mode at approximately 90° from incidence on the cylindrical samples, which may indicate the onset of more turbulent flow and PVD-like growth. Coatings deposited at non-perpendicular angles exhibited a higher density and nearly a 2× improvement in erosion performance when compared to coatings deposited with the torch normal to the surface.

  2. Deposits on heat exchanging surfaces, causes in the bleaching process and countermeasures; Belaeggningar paa vaermevaexlare, orsaker i blekprocessen och aatgaerder

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik [AaF-Energi och Miljoe AB, Stockholm (Sweden); Staahl, Charlotte; Widell, Lars [AaF-Celpap AB, Stockholm (Sweden)

    2003-06-01

    Energy conservation in process industry implies to a large extent recovery of heat (or cold) from a process stream and its utilization for another process stream. The savings of energy that can be achieved depend on the process streams, but also on the efficiency of the heat exchange. A small driving temperature difference is a condition for an extensive recovery and a satisfactory preservation of its quality, i.e. its temperature. As process streams contain compounds or components that can precipitate and form deposits on heat exchanging surfaces, the recovery of heat is degraded. In the pulp and paper industry, two trends combine to increase the extent of fouling: a larger degree of closure for the process and a change in pH-profile caused by a switch to elementary chlorine free bleaching. In this study, the occurrence of deposits has been investigated for the mills that produce mechanical pulp and for the fiber line in mills producing chemical pulp. Deposits on the evaporator surfaces are treated in a parallel study. Except for some plants, deposits are not an important problem today. That does not mean that there has not been any problem or that problems will not occur. The origin of deposits lies in the chemistry of the process, but deposits have consequences for the thermal energy management. A list of possible actions in order to avoid deposits or to mitigate their consequences has been dressed in this report. They should be considered with the following order of priority: avoiding that the compounds that may form deposits enter at all the process, section 6.1; avoiding that these compounds form a deposit once they have entered the process, section 6.2; cleaning if nothing else helps or costs too much, section 6.3. Some of these methods are well known or are conventional changes in the processes. Some of these methods are less well proven or less well documented. In a longer time perspective, the kidney technology that is being developed could contribute to

  3. Volcanogenic Uranium Deposits: Geology, Geochemical Processes, and Criteria for Resource Assessment

    Science.gov (United States)

    Nash, J. Thomas

    2010-01-01

    Felsic volcanic rocks have long been considered a primary source of uranium for many kinds of uranium deposits, but volcanogenic uranium deposits themselves have generally not been important resources. Until the past few years, resource summaries for the United States or the world generally include volcanogenic in the broad category of 'other deposits' because they comprised less than 0.5 percent of past production or estimated resources. Exploration in the United States from the 1940s through 1982 discovered hundreds of prospects in volcanic rocks, of which fewer than 20 had some recorded production. Intensive exploration in the late 1970s found some large deposits, but low grades (less than about 0.10 percent U3O8) discouraged economic development. A few deposits in the world, drilled in the 1980s and 1990s, are now known to contain large resources (>20,000 tonnes U3O8). However, research on ore-forming processes and exploration for volcanogenic deposits has lagged behind other kinds of uranium deposits and has not utilized advances in understanding of geology, geochemistry, and paleohydrology of ore deposits in general and epithermal deposits in particular. This review outlines new ways to explore and assess for volcanogenic deposits, using new concepts of convection, fluid mixing, and high heat flow to mobilize uranium from volcanic source rocks and form deposits that are postulated to be large. Much can also be learned from studies of epithermal metal deposits, such as the important roles of extensional tectonics, bimodal volcanism, and fracture-flow systems related to resurgent calderas. Regional resource assessment is helped by genetic concepts, but hampered by limited information on frontier areas and undiscovered districts. Diagnostic data used to define ore deposit genesis, such as stable isotopic data, are rarely available for frontier areas. A volcanic environment classification, with three classes (proximal, distal, and pre-volcanic structures

  4. Electrophoretic Deposition of Gallium with High Deposition Rate

    Directory of Open Access Journals (Sweden)

    Hanfei Zhang

    2014-12-01

    Full Text Available In this work, electrophoretic deposition (EPD is reported to form gallium thin film with high deposition rate and low cost while avoiding the highly toxic chemicals typically used in electroplating. A maximum deposition rate of ~0.6 μm/min, almost one order of magnitude higher than the typical value reported for electroplating, is obtained when employing a set of proper deposition parameters. The thickness of the film is shown to increase with deposition time when sequential deposition is employed. The concentration of Mg(NO32, the charging salt, is also found to be a critical factor to control the deposition rate. Various gallium micropatterns are obtained by masking the substrate during the process, demonstrating process compatibility with microfabrication. The reported novel approach can potentially be employed in a broad range of applications with Ga as a raw material, including microelectronics, photovoltaic cells, and flexible liquid metal microelectrodes.

  5. Particokinetics: computational analysis of the superparamagnetic iron oxide nanoparticles deposition process

    Science.gov (United States)

    Cárdenas, Walter HZ; Mamani, Javier B; Sibov, Tatiana T; Caous, Cristofer A; Amaro, Edson; Gamarra, Lionel F

    2012-01-01

    Background Nanoparticles in suspension are often utilized for intracellular labeling and evaluation of toxicity in experiments conducted in vitro. The purpose of this study was to undertake a computational modeling analysis of the deposition kinetics of a magnetite nanoparticle agglomerate in cell culture medium. Methods Finite difference methods and the Crank–Nicolson algorithm were used to solve the equation of mass transport in order to analyze concentration profiles and dose deposition. Theoretical data were confirmed by experimental magnetic resonance imaging. Results Different behavior in the dose fraction deposited was found for magnetic nanoparticles up to 50 nm in diameter when compared with magnetic nanoparticles of a larger diameter. Small changes in the dispersion factor cause variations of up to 22% in the dose deposited. The experimental data confirmed the theoretical results. Conclusion These findings are important in planning for nanomaterial absorption, because they provide valuable information for efficient intracellular labeling and control toxicity. This model enables determination of the in vitro transport behavior of specific magnetic nanoparticles, which is also relevant to other models that use cellular components and particle absorption processes. PMID:22745539

  6. Influence of laser irradiation on deposition characteristics of cold sprayed Stellite-6 coatings

    Science.gov (United States)

    Li, Bo; Jin, Yan; Yao, Jianhua; Li, Zhihong; Zhang, Qunli; Zhang, Xin

    2018-03-01

    Depositing hard materials such as Stellite-6 solely by cold spray (CS) is challengeable due to limited ability of plastic deformation. In this study, the deposition of Stellite-6 powder was achieved by supersonic laser deposition (SLD) which combines CS with synchronous laser irradiation. The surface morphology, deposition efficiency, track shape of Stellite-6 coatings produced over a range of laser irradiation temperatures were examined so as to reveal the effects of varying laser energy inputting on the deposition process of high strength material. The microstructure, phase composition and wear/corrosion resistant properties of the as-deposited Stellite-6 coatings were also investigated. The experimental results demonstrate that the surface flatness and deposition efficiency increase with laser irradiation temperature due to the softening effect induced by laser heating. The as-deposited Stellite-6 tracks show asymmetric shapes which are influenced by the relative configuration of powder stream and laser beam. The SLD coatings can preserve the original microstructure and phase of the feedstock material due to relatively low laser energy inputting, which result in the superior wear/corrosion resistant properties as compared to the counterpart prepared by laser cladding.

  7. Advanced deposition model for thermal activated chemical vapor deposition

    Science.gov (United States)

    Cai, Dang

    Thermal Activated Chemical Vapor Deposition (TACVD) is defined as the formation of a stable solid product on a heated substrate surface from chemical reactions and/or dissociation of gaseous reactants in an activated environment. It has become an essential process for producing solid film, bulk material, coating, fibers, powders and monolithic components. Global market of CVD products has reached multi billions dollars for each year. In the recent years CVD process has been extensively used to manufacture semiconductors and other electronic components such as polysilicon, AlN and GaN. Extensive research effort has been directed to improve deposition quality and throughput. To obtain fast and high quality deposition, operational conditions such as temperature, pressure, fluid velocity and species concentration and geometry conditions such as source-substrate distance need to be well controlled in a CVD system. This thesis will focus on design of CVD processes through understanding the transport and reaction phenomena in the growth reactor. Since the in situ monitor is almost impossible for CVD reactor, many industrial resources have been expended to determine the optimum design by semi-empirical methods and trial-and-error procedures. This approach has allowed the achievement of improvements in the deposition sequence, but begins to show its limitations, as this method cannot always fulfill the more and more stringent specifications of the industry. To resolve this problem, numerical simulation is widely used in studying the growth techniques. The difficulty of numerical simulation of TACVD crystal growth process lies in the simulation of gas phase and surface reactions, especially the latter one, due to the fact that very limited kinetic information is available in the open literature. In this thesis, an advanced deposition model was developed to study the multi-component fluid flow, homogeneous gas phase reactions inside the reactor chamber, heterogeneous surface

  8. Ion - beam assisted process in the physical deposition of organic thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, D; Spassova, E; Assa, J; Danev, G [Acad. J .Malinowski Central Laboratory of Photoprocesses, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl.109, 1113 Sofia (Bulgaria); Georgiev, A, E-mail: dean@clf.bas.b [University of Chemical Technology and Metallurgy, 8 Kl. Ohridski Blvd., 1756 Sofia (Bulgaria)

    2010-04-01

    A novel method was developed for physical deposition of thin polyimide layers by applying an argon plasma assisted process. The influence was investigated of the plasma on the combined molecular flux of the two thermally evaporated precursors - oxydianiline and pyromellitic dianhydride. The effects observed on the properties of the deposited films are explained with the increased energy of the precursor molecules resulting from the ion-molecular collisions. As could be expected, molecules with higher energy possess higher mobility and thus determine the modification of the films structure and their electrical properties.

  9. Contract Law, Due Process, and the NCAA.

    Science.gov (United States)

    Dickerson, Jaffe D.; Chapman, Mayer

    1978-01-01

    The NCAA has enjoyed almost total freedom from judicial scrutiny of its rules, procedures, and official acts in large part because of its private nature as an unincorporated association. The function of the NCAA, California State University, Hayward v NCAA, and due process of the student-athlete are discussed. (MLW)

  10. One-step electrodeposition process of CuInSe2: Deposition time effect

    Indian Academy of Sciences (India)

    Administrator

    CuInSe2 thin films were prepared by one-step electrodeposition process using a simplified two- electrodes system. ... homojunctions or heterojunctions (Rincon et al 1983). Efficiency of ... deposition times onto indium thin oxide (ITO)-covered.

  11. Enhancement of surface integrity of titanium alloy with copper by means of laser metal deposition process

    CSIR Research Space (South Africa)

    Erinosho, MF

    2016-04-01

    Full Text Available The laser metal deposition process possesses the combination of metallic powder and laser beam respectively. However, these combinations create an adhesive bonding that permanently solidifies the laser-enhanced-deposited powders. Titanium alloys (Ti...

  12. Novel sedimentological fingerprints link shifting depositional processes to Holocene climate transitions in East Greenland

    Science.gov (United States)

    van der Bilt, Willem G. M.; Rea, Brice; Spagnolo, Matteo; Roerdink, Desiree L.; Jørgensen, Steffen L.; Bakke, Jostein

    2018-05-01

    The Arctic warms faster than any other region of our planet. Besides melting glaciers, thawing permafrost and decreasing sea-ice, this amplified response affects earth surface processes. This geomorphological expression of climate change may alter landscapes and increase the frequency and magnitude of geohazards like floods or mass-movements. Beyond the short span of sparse monitoring time series, geological archives provide a valuable long-term context for future risk assessment. Lake sediment sequences are particularly promising in this respect as continuous recorders of surface process change. Over the past decade, the emergence of new techniques that characterize depositional signatures in more detail has enhanced this potential. Here, we present a well-dated Holocene-length lake sediment sequence from Ammassalik Island on southeast Greenland. This area is particularly sensitive to regional shifts in the Arctic climate system due to its location near the sea-ice limit, the Greenland Ice Sheet and the convergence of polar and Atlantic waters. The expression of Holocene change is fingerprinted using physical (grain size, organic content, density), visual (3-D Computed Tomography) and geochemical (X-Ray Fluorescence, X-Ray Diffraction) evidence. We show that three sharp transitions characterize the Holocene evolution of Ymer Lake. Between 10 and 9.5 cal. ka BP, rapid local glacier loss from the lake catchment culminated in an outburst flood. Following a quiescent Holocene climatic optimum, Neoglacial cooling, lengthening lake ice cover and shifting wind patterns prompted in-lake avalanching of sediments from 4.2 cal. ka BP onwards. Finally, glaciers reformed in the catchment around 1.2 cal. ka BP. The timing of these shifts is consistent with the regional expression of deglaciation, Neoglacial cooling and Little Ice Age-type glacier growth, respectively. The novel multi-proxy approach applied in this study rigorously links depositional sediment signatures to

  13. Research on Glass Frit Deposition Based on the Electrospray Process

    Directory of Open Access Journals (Sweden)

    Yifang Liu

    2016-04-01

    Full Text Available In this paper, the electrospray technology is used to easily deposit the glass frit into patterns at a micro-scale level. First, far-field electrospray process was carried out with a mixture of glass frit in the presence of ethanol. A uniform, smooth, and dense glass frit film was obtained, verifying that the electrospray technology was feasible. Then, the distance between the nozzle and the substrate was reduced to 2 mm to carry out near-field electrospray. The experimental process was improved by setting the range of the feed rate of the substrate to match both the concentration and the flow rate of the solution. Spray diameter could be less at the voltage of 2 kV, in which the glass frit film was expected to reach the minimum line width. A uniform glass frit film with a line width within the range of 400–500 μm was prepared when the speed of the substrate was 25 mm/s. It indicates that electrospray is an efficient technique for the patterned deposition of glass frit in wafer-level hermetic encapsulation.

  14. Salt Removal from the Uranium Deposits of Electrorefiner

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. W.; Park, K. M.; Lee, S. J.; Park, S. B.; Cho, C. H.; Choi, S. Y.; Lee, H. S.; Kim, J. G. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    Electrorefining is a key step in pyroprocessing. The electrorefining process is generally composed of two recovery steps. The deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. The solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. In the liquid cathode, cadmium metal should be removed to recover actinide product. A physical separation process, such as distillation separation, is more attractive than a chemical or dissolution process because physical processes generate much less secondary process. Distillation process was employed for the cathode processing due to the advantages of minimal generation of secondary waste, compact unit process, simple and low cost equipment. The basis for vacuum distillation separation is the difference in vapor pressures between salt and uranium. A solid cathode deposit is heated in a heating region and salt vaporizes, while non volatile uranium remains behind. It is very important to increase the throughput of the salt separation system due to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. The evaporation rate of the LiCl-KCl eutectic salt in vacuum distiller is not so high to come up with the generation capacity of uranium dendrites in electro-refiner. Therefore, wide evaporation area or high distillation temperature is necessary for the successful salt separation. In this study, the solid-liquid separation was proposed prior to distillation of salt and a feasibility of the separation of the liquid salt by a metallic wire mesh (sieve) was tested for the reduction of the burden of the following vacuum distillation process

  15. Salt Removal from the Uranium Deposits of Electrorefiner

    International Nuclear Information System (INIS)

    Kwon, S. W.; Park, K. M.; Lee, S. J.; Park, S. B.; Cho, C. H.; Choi, S. Y.; Lee, H. S.; Kim, J. G.

    2010-01-01

    Electrorefining is a key step in pyroprocessing. The electrorefining process is generally composed of two recovery steps. The deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. The solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. In the liquid cathode, cadmium metal should be removed to recover actinide product. A physical separation process, such as distillation separation, is more attractive than a chemical or dissolution process because physical processes generate much less secondary process. Distillation process was employed for the cathode processing due to the advantages of minimal generation of secondary waste, compact unit process, simple and low cost equipment. The basis for vacuum distillation separation is the difference in vapor pressures between salt and uranium. A solid cathode deposit is heated in a heating region and salt vaporizes, while non volatile uranium remains behind. It is very important to increase the throughput of the salt separation system due to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. The evaporation rate of the LiCl-KCl eutectic salt in vacuum distiller is not so high to come up with the generation capacity of uranium dendrites in electro-refiner. Therefore, wide evaporation area or high distillation temperature is necessary for the successful salt separation. In this study, the solid-liquid separation was proposed prior to distillation of salt and a feasibility of the separation of the liquid salt by a metallic wire mesh (sieve) was tested for the reduction of the burden of the following vacuum distillation process

  16. A discrete element based simulation framework to investigate particulate spray deposition processes

    KAUST Repository

    Mukherjee, Debanjan; Zohdi, Tarek I.

    2015-01-01

    © 2015 Elsevier Inc. This work presents a computer simulation framework based on discrete element method to analyze manufacturing processes that comprise a loosely flowing stream of particles in a carrier fluid being deposited on a target surface

  17. 34 CFR 300.508 - Due process complaint.

    Science.gov (United States)

    2010-07-01

    ... attending; (5) A description of the nature of the problem of the child relating to the proposed or refused initiation or change, including facts relating to the problem; and (6) A proposed resolution of the problem... section, the hearing officer must make a determination on the face of the due process complaint of whether...

  18. Different types of nitrogen deposition show variable effects on the soil carbon cycle process of temperate forests.

    Science.gov (United States)

    Du, Yuhan; Guo, Peng; Liu, Jianqiu; Wang, Chunyu; Yang, Ning; Jiao, Zhenxia

    2014-10-01

    Nitrogen (N) deposition significantly affects the soil carbon (C) cycle process of forests. However, the influence of different types of N on it still remained unclear. In this work, ammonium nitrate was selected as an inorganic N (IN) source, while urea and glycine were chosen as organic N (ON) sources. Different ratios of IN to ON (1 : 4, 2 : 3, 3 : 2, 4 : 1, and 5 : 0) were mixed with equal total amounts and then used to fertilize temperate forest soils for 2 years. Results showed that IN deposition inhibited soil C cycle processes, such as soil respiration, soil organic C decomposition, and enzymatic activities, and induced the accumulation of recalcitrant organic C. By contrast, ON deposition promoted these processes. Addition of ON also resulted in accelerated transformation of recalcitrant compounds into labile compounds and increased CO2 efflux. Meanwhile, greater ON deposition may convert C sequestration in forest soils into C source. These results indicated the importance of the IN to ON ratio in controlling the soil C cycle, which can consequently change the ecological effect of N deposition. © 2014 John Wiley & Sons Ltd.

  19. Study of the fluidized bed chemical vapor deposition process on very dense powder for nuclear applications

    International Nuclear Information System (INIS)

    Vanni, Florence

    2015-01-01

    This thesis is part of the development of low-enriched nuclear fuel, for the Materials Test Reactors (MTRs), constituted of uranium-molybdenum particles mixed with an aluminum matrix. Under certain conditions under irradiations, the U(Mo) particles interact with the aluminum matrix, causing unacceptable swelling of the fuel plate. To inhibit this phenomenon, one solution consists in depositing on the surface of the U(Mo) particles, a thin silicon layer to create a barrier effect. This thesis has concerned the study of the fluidized bed chemical vapor deposition (CVD) process to deposit silicon from silane, on the U(Mo) powder, which has an exceptional density of 17,500 kg/m 3 . To achieve this goal, two axes were treated during the thesis: the study and the optimization of the fluidization of a so dense powder, and then those of the silicon deposition process. For the first axis, a series of tests was performed on a surrogate tungsten powder in different columns made of glass and made of steel with internal diameters ranging from 2 to 5 cm, at room temperature and at high temperature (650 C) close to that of the deposits. These experiments helped to identify wall effects phenomena within the fluidized bed, which can lead to heterogeneous deposits or particles agglomeration. Some dimensions of the fluidization columns and operating conditions allowing a satisfactory fluidization of the powder were identified, paving the way for the study of silicon deposition. Several campaigns of deposition experiments on the surrogate powder and then on the U(Mo) powder were carried out in the second axis of the study. The influence of the bed temperature, the inlet molar fraction of silane diluted in argon, and the total gas flow of fluidization, was examined for different diameters of reactor and for various masses of powder. Morphological and structural characterization analyses (SEM, XRD..) revealed a uniform silicon deposition on all the powder and around each particle

  20. Effects of different needles and substrates on CuInS{sub 2} deposited by electrostatic spray deposition

    Energy Technology Data Exchange (ETDEWEB)

    Roncallo, S. [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Painter, J.D., E-mail: j.d.painter@cranfield.ac.u [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Healy, M.J.F. [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Ritchie, S.A.; Finnis, M.V. [Department of Engineering Systems and Management, Cranfield University, Shrivenham, Swindon SN6 8LA (United Kingdom); Rogers, K.D. [Cranfield Health, Cranfield University, Cranfield, Bedfordshire, MK43 0AL (United Kingdom); Scragg, J.J. [University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom); Dale, P.J. [Laboratoire Photovoltaique, University of Luxembourg, 41 Rue du Brill, L-4422, Belvaux (Luxembourg); Zoppi, G. [Northumbria Photovoltaics Applications Centre, Northumbria, University, Newcastle upon Tyne NE1 8ST (United Kingdom)

    2011-03-31

    Copper indium disulphide (CuInS{sub 2}) thin films were deposited using the electrostatic spray deposition method. The effects of applied voltage and solution flow rate on the aerosol cone shape, film composition, surface morphology and current conversion were investigated. The effect of aluminium substrates and transparent fluorine doped tin oxide (SnO{sub 2}:F) coated glass substrates on the properties of as-deposited CuInS{sub 2} films were analysed. An oxidation process occurs during the deposition onto the metallic substrates which forms an insulating layer between the photoactive film and substrate. The effects of two different spray needles on the properties of the as-deposited films were also studied. The results reveal that the use of a stainless steel needle results in contamination of the film due to the transfer of metal impurities through the spray whilst this is not seen for the glass needle. The films were characterised using a number of different analytical techniques such as X-ray diffraction, scanning electron microscopy, Rutherford back-scattering and secondary ion mass spectroscopy and opto-electronic measurements.

  1. Understanding snow-transport processes shaping the mountain snow-cover

    Directory of Open Access Journals (Sweden)

    R. Mott

    2010-12-01

    Full Text Available Mountain snow-cover is normally heterogeneously distributed due to wind and precipitation interacting with the snow cover on various scales. The aim of this study was to investigate snow deposition and wind-induced snow-transport processes on different scales and to analyze some major drift events caused by north-west storms during two consecutive accumulation periods. In particular, we distinguish between the individual processes that cause specific drifts using a physically based model approach. Very high resolution wind fields (5 m were computed with the atmospheric model Advanced Regional Prediction System (ARPS and used as input for a model of snow-surface processes (Alpine3D to calculate saltation, suspension and preferential deposition of precipitation. Several flow features during north-west storms were identified with input from a high-density network of permanent and mobile weather stations and indirect estimations of wind directions from snow-surface structures, such as snow dunes and sastrugis. We also used Terrestrial and Airborne Laser Scanning measurements to investigate snow-deposition patterns and to validate the model. The model results suggest that the in-slope deposition patterns, particularly two huge cross-slope cornice-like drifts, developed only when the prevailing wind direction was northwesterly and were formed mainly due to snow redistribution processes (saltation-driven. In contrast, more homogeneous deposition patterns on a ridge scale were formed during the same periods mainly due to preferential deposition of precipitation. The numerical analysis showed that snow-transport processes were sensitive to the changing topography due to the smoothing effect of the snow cover.

  2. Mapping process and age of Quaternary deposits on Santa Rosa Island, Channel Islands National Park, California

    Science.gov (United States)

    Schmidt, K. M.; Minor, S. A.; Bedford, D.

    2016-12-01

    Employing a geomorphic process-age classification scheme, we mapped the Quaternary surficial geology of Santa Rosa (SRI) within the Channel Islands National Park. This detailed (1:12,000 scale) map represents upland erosional transport processes and alluvial, fluvial, eolian, beach, marine terrace, mass wasting, and mixed depositional processes. Mapping was motivated through an agreement with the National Park Service and is intended to aid natural resource assessments, including post-grazing disturbance recovery and identification of mass wasting and tectonic hazards. We obtained numerous detailed geologic field observations, fossils for faunal identification as age control, and materials for numeric dating. This GPS-located field information provides ground truth for delineating map units and faults using GIS-based datasets- high-resolution (sub-meter) aerial imagery, LiDAR-based DEMs and derivative raster products. Mapped geologic units denote surface processes and Quaternary faults constrain deformation kinematics and rates, which inform models of landscape change. Significant findings include: 1) Flights of older Pleistocene (>120 ka) and possibly Pliocene marine terraces were identified beneath younger alluvial and eolian deposits at elevations as much as 275 m above modern sea level. Such elevated terraces suggest that SRI was a smaller, more submerged island in the late Neogene and (or) early Pleistocene prior to tectonic uplift. 2) Structural and geomorphic observations made along the potentially seismogenic SRI fault indicate a protracted slip history during the late Neogene and Quaternary involving early normal slip, later strike slip, and recent reverse slip. These changes in slip mode explain a marked contrast in island physiography across the fault. 3) Many of the steeper slopes are dramatically stripped of regolith, with exposed bedrock and deeply incised gullies, presumably due effects related to past grazing practices. 4) Surface water presence is

  3. Thermodynamic analysis of processes proceeding on (111) faces of diamond during chemical vapour deposition

    International Nuclear Information System (INIS)

    Piekarczyk, W.; Prawer, S.

    1992-01-01

    Chemically vapour deposited diamond is commonly synthesized from activated hydrogen-rich, carbon/hydrogen gas mixtures under conditions which should, from a thermodynamic equilibrium point of view, favour the production of graphite. Much remains to be understood about why diamond, and not graphite, forms under these conditions. However, it is well known that the presence of atomic hydrogen, is crucial to the success of diamond deposition. As part of an attempt to better understand the deposition process, a thermodynamic analysis of the process was performed on diamond (111) faces in hydrogen rich environments. It is shown that the key role of atomic hydrogen is to inhibit the reconstruction of the (111) face to an sp 2 -bonded structure, which would provide a template for graphite, rather than diamond formation. The model correctly predicts experimentally determined trends in growth rate and diamond film quality as a function of methane concentration in the stating gas mixture. 17 refs., 4 figs

  4. Thick film laser induced forward transfer for deposition of thermally and mechanically sensitive materials

    International Nuclear Information System (INIS)

    Kattamis, Nicholas T.; Purnick, Priscilla E.; Weiss, Ron; Arnold, Craig B.

    2007-01-01

    Laser forward transfer processes incorporating thin absorbing films can be used to deposit robust organic and inorganic materials but the deposition of more delicate materials has remained elusive due to contamination and stress induced during the transfer process. Here, we present the approach to high resolution patterning of sensitive materials by incorporating a thick film polymer absorbing layer that is able to dissipate shock energy through mechanical deformation. Multiple mechanisms for transfer as a function of incident laser energy are observed and we show viable and contamination-free deposition of living mammalian embryonic stem cells

  5. Beneficial effects of laser irradiation on the deposition process of diamond/Ni60 composite coating with cold spray

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jianhua, E-mail: laser@zjut.edu.cn; Yang, Lijing; Li, Bo; Li, Zhihong

    2015-03-01

    Graphical abstract: - Highlights: • The hard Ni-based alloy powder as matrix in diamond composite coating was studied. • The influence of laser on diamond distribution of composite coating was analyzed. • The graphitization of diamond was prohibited in supersonic laser deposition process. • The abrasion mechanisms of diamond/Ni60 composite coating were discussed. - Abstract: Although cold spray process has many unique advantages over other coating techniques, it has difficulties in depositing hard materials. This article presents a study in the beneficial effects of laser irradiation on the fabrication process of diamond/Ni60 composite coating using cold spray. The focus of this research is on the comparison between the composite coatings produced with laser cladding (LC) and with supersonic laser deposition (SLD), with respect to diamond graphitization and tribological properties, thus to demonstrate the beneficial effects of laser irradiation on the cold spray process. The influence of deposition temperature on the coating characteristics, such as deposition efficiency, diamond volume fraction, microstructure and phase is also investigated. The tribological properties of the diamond/Ni60 composite coating produced with SLD are determined using a pin-on-disc tribometer, along with the diamond/Ni60 coating produced using LC with the optimal process parameters for comparison. The experimental results show that with the assistance of laser irradiation, diamond/Ni60 composite coating can be successfully deposited using cold spray; the obtained coating is superior to that processed with LC, because SLD can suppress the graphitization of the diamond particles. The diamond/Ni60 composite coating fabricated with SLD has much better tribological properties than the LC coating.

  6. Feature based Weld-Deposition for Additive Manufacturing of Complex Shapes

    Science.gov (United States)

    Panchagnula, Jayaprakash Sharma; Simhambhatla, Suryakumar

    2018-06-01

    Fabricating functional metal parts using Additive Manufacturing (AM) is a leading trend. However, realizing overhanging features has been a challenge due to the lack of support mechanism for metals. Powder-bed fusion techniques like, Selective Laser Sintering (SLS) employ easily-breakable-scaffolds made of the same material to realize the overhangs. However, the same approach is not extendible to deposition processes like laser or arc based direct energy deposition processes. Although it is possible to realize small overhangs by exploiting the inherent overhanging capability of the process or by blinding some small features like holes, the same cannot be extended for more complex geometries. The current work presents a novel approach for realizing complex overhanging features without the need of support structures. This is possible by using higher order kinematics and suitably aligning the overhang with the deposition direction. Feature based non-uniform slicing and non-uniform area-filling are some vital concepts required in realizing the same and are briefly discussed here. This method can be used to fabricate and/or repair fully dense and functional components for various engineering applications. Although this approach has been implemented for weld-deposition based system, the same can be extended to any other direct energy deposition processes also.

  7. Effect of Welding Speed on Microstructure and Mechanical Properties due to The Deposition of Reinforcements on Friction Stir Welded Dissimilar Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Baridula Ravinder Reddy

    2017-01-01

    Full Text Available The strength of the welded joint obtained by solid state stir welding process was found to be improved as compared to fusion welding process. The deposition of reinforcements during friction stir welding process can further enhance the strength of the welded joint by locking the movement of grain boundaries. In the present study, the aluminium alloys AA2024 and AA7075 were welded effectively by depositing the multi-walled carbon nanotubes in to the stir zone. The mechanical properties and microstructures were studied by varying the traverse speed at constant rotational speed. The results show that rotating tool pin stirring action and heat input play an important role in controlling the grain size. The carbon nanotubes were found to be distributed uniformly at a welding speed (traverse speed of 80mm/min. This enhanced the mechanical properties of the welded joint. The microstructure and Electron dispersive X-ray analysis (EDX studies indicate that the deposition of carbon nanotubes in the stir zone was influenced by the traverse speed.

  8. Particokinetics: computational analysis of the superparamagnetic iron oxide nanoparticles deposition process

    Directory of Open Access Journals (Sweden)

    Cárdenas WH

    2012-06-01

    Full Text Available Walter HZ Cárdenas, Javier B Mamani, Tatiana T Sibov, Cristofer A Caous, Edson Amaro Jr, Lionel F GamarraInstituto do Cérebro, Hospital Israelita Albert Einstein, São Paulo, BrazilBackground: Nanoparticles in suspension are often utilized for intracellular labeling and evaluation of toxicity in experiments conducted in vitro. The purpose of this study was to undertake a computational modeling analysis of the deposition kinetics of a magnetite nanoparticle agglomerate in cell culture medium.Methods: Finite difference methods and the Crank-Nicolson algorithm were used to solve the equation of mass transport in order to analyze concentration profiles and dose deposition. Theoretical data were confirmed by experimental magnetic resonance imaging.Results: Different behavior in the dose fraction deposited was found for magnetic nanoparticles up to 50 nm in diameter when compared with magnetic nanoparticles of a larger diameter. Small changes in the dispersion factor cause variations of up to 22% in the dose deposited. The experimental data confirmed the theoretical results.Conclusion: These findings are important in planning for nanomaterial absorption, because they provide valuable information for efficient intracellular labeling and control toxicity. This model enables determination of the in vitro transport behavior of specific magnetic nanoparticles, which is also relevant to other models that use cellular components and particle absorption processes.Keywords: magnetite, nanoparticles, diffusion, sedimentation, agglomerates, computational modeling, cellular labeling, magnetic resonance imaging

  9. OVPD-processed OLED for general lighting

    OpenAIRE

    Bösing, Manuel

    2012-01-01

    Due to continuous advancements of materials for organic light emitting diodes (OLED) a new field of application currently opens up for OLED technology: General lighting. A significant reduction of OLED production cost might be achieved by employing organic vapor phase deposition (OVPD). OVPD is a novel process for depositing organic thin films from the gas phase. In contrast to the well established process of vacuum thermal evaporation (VTE), OVPD allows to achieve much higher deposition rate...

  10. Solution processed deposition of electron transport layers on perovskite crystal surface—A modeling based study

    Energy Technology Data Exchange (ETDEWEB)

    Mortuza, S.M.; Taufique, M.F.N.; Banerjee, Soumik, E-mail: soumik.banerjee@wsu.edu

    2017-02-01

    Highlights: • The model determined the surface coverage of solution-processed film on perovskite. • Calculated surface density map provides insight into morphology of the monolayer. • Carbonyl oxygen atom of PCBM strongly attaches to the (110) surface of perovskite. • Uniform distribution of clusters on perovskite surface at lower PCBM concentration. • Deposition rate of PCBM on the surface is very high at initial stage of film growth. - Abstract: The power conversion efficiency (PCE) of planar perovskite solar cells (PSCs) has reached up to ∼20%. However, structural and chemicals defects that lead to hysteresis in the perovskite based thin film pose challenges. Recent work has shown that thin films of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) deposited on the photo absorption layer, using solution processing techniques, minimize surface pin holes and defects thereby increasing the PCE. We developed and employed a multiscale model based on molecular dynamics (MD) and kinetic Monte Carlo (kMC) to establish a relationship between deposition rate and surface coverage on perovskite surface. The MD simulations of PCBMs dispersed in chlorobenzene, sandwiched between (110) perovskite substrates, indicate that PCBMs are deposited through anchoring of the oxygen atom of carbonyl group to the exposed lead (Pb) atom of (110) perovskite surface. Based on rates of distinct deposition events calculated from MD, kMC simulations were run to determine surface coverage at much larger time and length scales than accessible by MD alone. Based on the model, a generic relationship is established between deposition rate of PCBMs and surface coverage on perovskite crystal. The study also provides detailed insights into the morphology of the deposited film.

  11. Solution processed deposition of electron transport layers on perovskite crystal surface—A modeling based study

    International Nuclear Information System (INIS)

    Mortuza, S.M.; Taufique, M.F.N.; Banerjee, Soumik

    2017-01-01

    Highlights: • The model determined the surface coverage of solution-processed film on perovskite. • Calculated surface density map provides insight into morphology of the monolayer. • Carbonyl oxygen atom of PCBM strongly attaches to the (110) surface of perovskite. • Uniform distribution of clusters on perovskite surface at lower PCBM concentration. • Deposition rate of PCBM on the surface is very high at initial stage of film growth. - Abstract: The power conversion efficiency (PCE) of planar perovskite solar cells (PSCs) has reached up to ∼20%. However, structural and chemicals defects that lead to hysteresis in the perovskite based thin film pose challenges. Recent work has shown that thin films of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) deposited on the photo absorption layer, using solution processing techniques, minimize surface pin holes and defects thereby increasing the PCE. We developed and employed a multiscale model based on molecular dynamics (MD) and kinetic Monte Carlo (kMC) to establish a relationship between deposition rate and surface coverage on perovskite surface. The MD simulations of PCBMs dispersed in chlorobenzene, sandwiched between (110) perovskite substrates, indicate that PCBMs are deposited through anchoring of the oxygen atom of carbonyl group to the exposed lead (Pb) atom of (110) perovskite surface. Based on rates of distinct deposition events calculated from MD, kMC simulations were run to determine surface coverage at much larger time and length scales than accessible by MD alone. Based on the model, a generic relationship is established between deposition rate of PCBMs and surface coverage on perovskite crystal. The study also provides detailed insights into the morphology of the deposited film.

  12. Intensified Vegetation Water Use due to Soil Calcium Leaching under Acid Deposition

    Science.gov (United States)

    Lanning, M.; Wang, L.; Scanlon, T. M.; Vadeboncoeur, M. A.; Adams, M. B.; Epstein, H. E.; Druckenbrod, D.

    2017-12-01

    Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. Nitrate and sulfate deposition from fossil fuel burning has caused significant soil acidification, leading to the leaching of soil base cations. From a physiological perspective, plants require various soil cations as signaling and regulatory ions as well as integral parts of structural molecules; a depletion of soil cations can cause reduced productivity and abnormal responses to environmental change. A deficiency in calcium could also potentially prolong stomatal opening, leading to increased transpiration until enough calcium had been acquired to stimulate stomatal closure. Based on the plant physiology and the nature of acidic deposition, we hypothesize that depletion of the soil calcium supply, induced by acid deposition, would intensify vegetation water use at the watershed scale. We tested this hypothesis by analyzing a long-term and unique data set (1989-2012) of soil lysimeter data along with stream flow and evapotranspiration data at the Fernow Experimental Forest. We show that depletion of soil calcium by acid deposition can intensify vegetation water use ( 10% increase in evapotranspiration and depletion in soil water) for the first time. These results are critical to understanding future water availability, biogeochemical cycles, and surficial energy flux and may help reduce uncertainties in terrestrial biosphere models.

  13. A Longitudinal Study of Special Education Due Process Hearings in Massachusetts

    Directory of Open Access Journals (Sweden)

    William H. Blackwell

    2015-03-01

    Full Text Available Of the three formal dispute resolution procedures provided by the Individuals With Disabilities Education Act of 2004(IDEA, due process hearings are the most costly in terms of time, fiscal resources, and impact on relationships between school personnel and parents. This study examined 258 due process hearings held over the past 8 years in Massachusetts to examine the characteristics of students at the center of these disputes, the issues that were addressed in the hearings, and the representation utilized by parents and school districts. The findings from this study indicated that (a Massachusetts school districts utilized attorney representation and won due process hearings at notably higher levels than parents, and (b the most frequently addressed issues at due process hearings were Individualized Education Program (IEP development/implementation and educational program placement, which are issues that represent the core mandate of IDEA to provide a free appropriate public education in the least restrictive environment (34 C.F.R. §300.300, 300.550. The authors present recommendations for policy actions and areas for future research.

  14. Self-catalytic growth of tin oxide nanowires by chemical vapor deposition process

    CSIR Research Space (South Africa)

    Thabethe, BS

    2013-01-01

    Full Text Available The authors report on the synthesis of tin oxide (SnO(sub2)) nanowires by a chemical vapor deposition (CVD) process. Commercially bought SnO nanopowders were vaporized at 1050°C for 30 minutes with argon gas continuously passing through the system...

  15. Intelligent process control of fiber chemical vapor deposition

    Science.gov (United States)

    Jones, John Gregory

    Chemical Vapor Deposition (CVD) is a widely used process for the application of thin films. In this case, CVD is being used to apply a thin film interface coating to single crystal monofilament sapphire (Alsb2Osb3) fibers for use in Ceramic Matrix Composites (CMC's). The hot-wall reactor operates at near atmospheric pressure which is maintained using a venturi pump system. Inert gas seals obviate the need for a sealed system. A liquid precursor delivery system has been implemented to provide precise stoichiometry control. Neural networks have been implemented to create real-time process description models trained using data generated based on a Navier-Stokes finite difference model of the process. Automation of the process to include full computer control and data logging capability is also presented. In situ sensors including a quadrupole mass spectrometer, thermocouples, laser scanner, and Raman spectrometer have been implemented to determine the gas phase reactants and coating quality. A fuzzy logic controller has been developed to regulate either the gas phase or the in situ temperature of the reactor using oxygen flow rate as an actuator. Scanning electron microscope (SEM) images of various samples are shown. A hierarchical control structure upon which the control structure is based is also presented.

  16. Mining and processing of uranium deposits in Salamanca, Spain

    International Nuclear Information System (INIS)

    Gomez Jaen, J.P.; Otero, J.; Serrano, J.R.; Membrillera, J.R.; Josa, J.M.

    1977-01-01

    In July, 1974, Empresa Nacional del Uranio, S.A. (ENUSA), took the decision to mine uranium in the province of Salamanca, based on geological and processing studies carried out by the Junta de Energia Nuclear (JEN). The milling plant was designed by JEN and assembled by ENUSA, and operations were begun on 22 May, 1975. The orebody, FE-1, is composed of slate of Cambrain age and the fissures are filled by primary minerals. Secondary minerals are impregnated in the zone affected by the hydrostatic level. The orebody is of the stockwork type in which carbonaceous matter has acted as a reducing agent. The average grade of the ore is 0.09% U 3 O 8 at a cutoff grade of 0.02% U 3 O 8 : the deposit is therefore among the lowest-grade deposits that are currently mined. Annual production is 1 200 000 t of rock, of which 200 000 t is ore-bearing. The milling plant uses a static heap-leaching method, followed by solvent extraction (tertiary amines) and precipitation by ammonia. Joint studies by JEN and ENUSA have led to the introduction of modifications that have increased the production capacity from 75 to 112 t U 3 O 8 per annum with no significant alteration in the initial planned investment. The total recovery after processing is 75% of the U 3 O 8 contained in the ore. Approximately 100 people are employed in the overall operation. ENUSA has decided to expand operations in Salamanca with the construction of a new milling plant (technological aid by JEN), which will be capable of processing 825 000 t of ore per year, with an annual production of 500 t U 3 O 8 . The new plant is expected to begin operations in 1979. (author)

  17. The Influence of the Powder Stream on High-Deposition-Rate Laser Metal Deposition with Inconel 718

    Directory of Open Access Journals (Sweden)

    Chongliang Zhong

    2017-10-01

    Full Text Available For the purpose of improving the productivity of laser metal deposition (LMD, the focus of current research is set on increasing the deposition rate, in order to develop high-deposition-rate LMD (HDR-LMD. The presented work studies the effects of the powder stream on HDR-LMD with Inconel 718. Experiments have been designed and conducted by using different powder feeding nozzles—a three-jet and a coaxial powder feeding nozzle—since the powder stream is mainly determined by the geometry of the powder feeding nozzle. After the deposition trials, metallographic analysis of the samples has been performed. The laser intensity distribution (LID and the powder stream intensity distribution (PID have been characterized, based on which the processes have been simulated. Finally, for verifying and correcting the used models for the simulation, the simulated results have been compared with the experimental results. Through the conducted work, suitable boundary conditions for simulating the process with different powder streams has been determined, and the effects of the powder stream on the process have also been determined. For a LMD process with a three-jet nozzle a substantial part of the powder particles that hit the melt pool surface are rebounded; for a LMD process with a coaxial nozzle almost all the particles are caught in the melt pool. This is due to the different particle velocities achieved with the two different nozzles. Moreover, the powder stream affects the heat exchange between the heated particles and the melt pool: a surface boundary condition applies for a powder stream with lower particle velocities, in the experiment provided by a three-jet nozzle, and a volumetric boundary condition applies for a powder stream with higher particle velocities, provided by a coaxial nozzle.

  18. The IRSN publishes an assessment of doses received in Japan by external irradiation due to radioactive deposits caused by the Fukushima-Daiichi power plant accident

    International Nuclear Information System (INIS)

    2011-01-01

    This document first describes how dry and wet radioactive deposits are formed. It also indicates their main components: iodine 131 and 132, caesium 134, 136 and 137, tellurium 132, and barium 140. It describes the different exposure ways due to radioactive deposits in the environment. A map indicates dose level assessments few tens of kilometres around the Fukushima power plant. A brief comment of this map is proposed

  19. Investigating Dry Deposition of Ozone to Vegetation

    Science.gov (United States)

    Silva, Sam J.; Heald, Colette L.

    2018-01-01

    Atmospheric ozone loss through dry deposition to vegetation is a critically important process for both air quality and ecosystem health. The majority of atmospheric chemistry models calculate dry deposition using a resistance-in-series parameterization by Wesely (1989), which is dependent on many environmental variables and lookup table values. The uncertainties contained within this parameterization have not been fully explored, ultimately challenging our ability to understand global scale biosphere-atmosphere interactions. In this work, we evaluate the GEOS-Chem model simulation of ozone dry deposition using a globally distributed suite of observations. We find that simulated daytime deposition velocities generally reproduce the magnitude of observations to within a factor of 1.4. When correctly accounting for differences in land class between the observations and model, these biases improve, most substantially over the grasses and shrubs land class. These biases do not impact the global ozone burden substantially; however, they do lead to local absolute changes of up to 4 ppbv and relative changes of 15% in summer surface concentrations. We use MERRA meteorology from 1979 to 2008 to assess that the interannual variability in simulated annual mean ozone dry deposition due to model input meteorology is small (generally less than 5% over vegetated surfaces). Sensitivity experiments indicate that the simulation is most sensitive to the stomatal and ground surface resistances, as well as leaf area index. To improve ozone dry deposition models, more measurements are necessary over rainforests and various crop types, alongside constraints on individual depositional pathways and other in-canopy ozone loss processes.

  20. Preparation of iron-deposited graphite surface for application as cathode material during electrochemical vat-dyeing process

    International Nuclear Information System (INIS)

    Anbu Kulandainathan, M.; Kiruthika, K.; Christopher, G.; Babu, K. Firoz; Muthukumaran, A.; Noel, M.

    2008-01-01

    Iron-deposited graphite surfaces were prepared, characterized and employed as cathode materials for electrochemical vat-dyeing process containing very low concentration of sodium dithionite. The electrodeposition, in presence of ammonium thiocyanate and gelatin or animal glue as binding additives, were found to give finer iron deposits for improved electrochemical dyeing application. The electrodeposits were characterized using scanning electron microscopy, electron-dispersive X-ray spectroscopy and X-ray diffraction methods, before and after electrochemical dyeing process. The electrochemical activity of the iron-deposited graphite electrodes always stored in water seems to depend on the surface-bound Fe 3+ /Fe 2+ redox species. Vat dyes like C.I. Vat Violet 1, C.I. Vat Green 1 and C.I. Vat Blue 4 could be efficiently dyed employing these above electrode materials. The colour intensity and washing fastness of the dyed fabrics were found to be equal with conventionally dyed fabrics. The electrodes could also be reused for the dyeing process

  1. Effect of voltage on the characteristics of magnesium-lanthanum deposits synthesized by an electrodeposition process

    Energy Technology Data Exchange (ETDEWEB)

    Sahli, M. [Laboratoire de Physique Energétique, Université de Constantine 1 (Algeria); Chetehouna, K.; Gascoin, N. [INSA-CVL, Univ. Orléans, PRISME, EA 4229, F-18020, Bourges (France); Bellel, N. [Laboratoire de Physique Energétique, Université de Constantine 1 (Algeria); Tadini, P., E-mail: tadini.pietro@gmail.com [INSA-CVL, Univ. Orléans, PRISME, EA 4229, F-18020, Bourges (France)

    2017-04-15

    This work deals with the characterization of magnesium-lanthanum powders deposits produced with an electrodeposition technique using an aqueous solution based on magnesium chloride and lanthanum(III) nitrate. In recent years, the interest for magnesium-based alloys is growing due to their potential use as solid state systems for hydrogen storage. This work is a preliminary study on the synthesis of magnesium-lanthanum powders oriented to their later evaluation in systems for hydrogen storage. Magnesium and Lanthanum are deposited on a copper plate used as a cathode. Chemical composition, structure and morphology are investigated by EDS, XRD, FTIR and SEM. The effect of voltage on powders characteristics is studied considering three values (3, 3.5 and 4 V). EDS analysis shows the presence of three major elements (Mg, La and O) with a little amount of Cl. The weight percentages of Mg and O increase whereas the one of La decreases with the growth of voltage. Morphological characterization reveals that heterogeneous chemical structures are formed on the surface of the electrode and the size of aggregates decreases with the increase of voltage. From the results of X-ray analysis the deposits reveal the significant presence of two phases: Mg(OH){sub 2} and La(OH){sub 3}. The peaks originating from the Mg(OH){sub 2} phase has a non-monotonic behavior and those of La(OH){sub 3} phase increase with the increase of voltage. FTIR analysis confirms the presence of the two phases identified in XRD diffractograms and exhibits that their corresponding transmittance values increase for higher voltage values. - Highlights: • Synthesis of magnesium-lanthanum deposits by an electrodeposition process. • Voltage effect is investigated using different physicochemical analysis techniques (EDS, XRD, FTIR and SEM). • The EDS analysis shows the presence of three major elements (Mg, La and O) and a little amount of Cl. • Two phases, namely Mg(OH){sub 2} and La(OH){sub 3} are

  2. Sedimentological characteristics and depositional processes of sediment gravity flows in rift basins: The Palaeogene Dongying and Shahejie formations, Bohai Bay Basin, China

    Science.gov (United States)

    Liu, Lei; Chen, Hongde; Zhong, Yijiang; Wang, Jun; Xu, Changgui; Chen, Anqing; Du, Xiaofeng

    2017-10-01

    Sediment gravity flow deposits are common, particularly in sandy formations, but their origin has been a matter of debate and there is no consensus about the classification of such deposits. However, sediment gravity flow sandstones are economically important and have the potential to meet a growing demand in oil and gas exploration, so there is a drive to better understand them. This study focuses on sediment gravity flow deposits identified from well cores in Palaeogene deposits from the Liaodong Bay Depression in Bohai Bay Basin, China. We classify the sediment gravity flow deposits into eight lithofacies using lithological characteristics, grain size, and sedimentary structures, and interpret the associated depositional processes. Based on the scale, spatial distribution, and contact relationships of sediment gravity flow deposits, we defined six types of lithofacies associations (LAs) that reflect transformation processes and depositional morphology: LA1 (unconfined proximal breccia deposits), LA2 (confined channel deposits), LA3 (braided-channel lobe deposits), LA4 (unconfined lobe deposits), LA5 (distal sheet deposits), and LA6 (non-channelized sheet deposits). Finally, we established three depositional models that reflect the sedimentological characteristics and depositional processes of sediment gravity flow deposits: (1) slope-apron gravel-rich depositional model, which involves cohesive debris flows deposited as LA1 and dilute turbidity currents deposited as LA5; (2) non-channelized surge-like turbidity current depositional model, which mainly comprises sandy slumping, suspended load dominated turbidity currents, and dilute turbidity currents deposited as LA5 and LA6; and (3) channelized subaqueous-fan depositional model, which consists of non-cohesive bedload dominated turbidity currents, suspended load dominated turbidity currents, and dilute turbidity currents deposited as LA2-LA5, originating from sustained extrabasinal turbidity currents

  3. Silicon oxide barrier films deposited on PET foils in pulsed plasmas: influence of substrate bias on deposition process and film properties

    International Nuclear Information System (INIS)

    Steves, S; Bibinov, N; Awakowicz, P; Ozkaya, B; Liu, C-N; Ozcan, O; Grundmeier, G

    2013-01-01

    A widely used plastic for packaging, polyethylene terephtalate (PET) offers limited barrier properties against gas permeation. For many applications of PET (from food packaging to micro electronics) improved barrier properties are essential. A silicon oxide barrier coating of PET foils is applied by means of a pulsed microwave driven low-pressure plasma. While the adjustment of the microwave power allows for a control of the ion production during the plasma pulse, a substrate bias controls the energy of ions impinging on the substrate. Detailed analysis of deposited films applying oxygen permeation measurements, x-ray photoelectron spectroscopy and atomic force microscopy are correlated with results from plasma diagnostics describing the deposition process. The influence of a change in process parameters such as gas mixture and substrate bias on the gas temperature, electron density, mean electron energy, ion energy and the atomic oxygen density is studied. An additional substrate bias results in an increase in atomic oxygen density up to a factor of 6, although plasma parameter such as electron density of n e = 3.8 ± 0.8 × 10 17 m −3 and electron temperature of k B T e = 1.7 ± 0.1 eV are unmodified. It is shown that atomic oxygen densities measured during deposition process higher than n O = 1.8 × 10 21 m −3 yield in barrier films with a barrier improvement factor up to 150. Good barrier films are highly cross-linked and show a smooth morphology. (paper)

  4. Deposit control in process cooling water systems

    International Nuclear Information System (INIS)

    Venkataramani, B.

    1981-01-01

    In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

  5. REE enrichment in granite-derived regolith deposits of the southeast United States: Prospective source rocks and accumulation processes

    Science.gov (United States)

    Foley, Nora K.; Ayuso, Robert A.; Simandl, G.J.; Neetz, M.

    2015-01-01

    The Southeastern United States contains numerous anorogenic, or A-type, granites, which constitute promising source rocks for REE-enriched ion adsorption clay deposits due to their inherently high concentrations of REE. These granites have undergone a long history of chemical weathering, resulting in thick granite-derived regoliths, akin to those of South China, which supply virtually all heavy REE and Y, and a significant portion of light REE to global markets. Detailed comparisons of granite regolith profiles formed on the Stewartsville and Striped Rock plutons, and the Robertson River batholith (Virginia) indicate that REE are mobile and can attain grades comparable to those of deposits currently mined in China. A REE-enriched parent, either A-type or I-type (highly fractionated igneous type) granite, is thought to be critical for generating the high concentrations of REE in regolith profiles. One prominent feature we recognize in many granites and mineralized regoliths is the tetrad behaviour displayed in REE chondrite-normalized patterns. Tetrad patterns in granite and regolith result from processes that promote the redistribution, enrichment, and fractionation of REE, such as late- to post- magmatic alteration of granite and silicate hydrolysis in the regolith. Thus, REE patterns showing tetrad effects may be a key for discriminating highly prospective source rocks and regoliths with potential for REE ion adsorption clay deposits.

  6. Polymer deposition morphology by electrospray deposition - Modifications through distance variation

    International Nuclear Information System (INIS)

    Altmann, K.; Schulze, R.-D.; Friedrich, J.

    2014-01-01

    Electrospray deposition (ESD) of highly diluted polymers was examined with regard to the deposited surface structure. Only the flight distance (flight time) onto the resulting deposited surface was varied from 20 to 200 mm. An apparatus without any additional heating or gas flows was used. Polyacrylic acid (PAA) and polyallylamine (PAAm) in methanol were deposited on Si wafers. The polymer layers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, derivatization reactions and Fourier transform infrared spectroscopy using a grazing incidence unit. SEM images illustrated the changing structures of PAA and PAAm. For PAA the deposited structure changed from a smooth film (20 mm) to a film with individual droplets on the coated surface (100 mm and 200 mm), while for PAAm individual droplets can be seen at all distances. The ESD process with cascades of splitting droplets slows down for PAA after distances greater than 40 mm. In contrast, the ESD process for PAAm is nearly stopped within the first flight distance of 20 mm. Residual solvent analysis showed that most of the solvent evaporated within the first 20 mm capillary-sample distance. - Highlights: • We deposited polyacrylic acid and polyallylamine by electrospray ionization (ESI). • The morphology in dependence of flight distance (20 mm to 200 mm) was analyzed. • The amount of residual solvent after deposition was determined. • ESI-process slows down for polyacrylic acid after 40 mm flight distance. • ESI-Process is complete for polyallylamine within the first 20 mm

  7. Dual Nitrate Isotopes in Dry Deposition: Utility for Partitioning Nox Source Contributions to Landscape Nitrogen Deposition

    Science.gov (United States)

    Dry deposition is a major component of total nitrogen deposition and thus an important source of bioavailable nitrogen to ecosystems. However, relative to wet deposition, less is known regarding the sources and spatial variability of dry deposition. This is in part due to diffi...

  8. Low-Temperature Process for Atomic Layer Chemical Vapor Deposition of an Al2O3 Passivation Layer for Organic Photovoltaic Cells.

    Science.gov (United States)

    Kim, Hoonbae; Lee, Jihye; Sohn, Sunyoung; Jung, Donggeun

    2016-05-01

    Flexible organic photovoltaic (OPV) cells have drawn extensive attention due to their light weight, cost efficiency, portability, and so on. However, OPV cells degrade quickly due to organic damage by water vapor or oxygen penetration when the devices are driven in the atmosphere without a passivation layer. In order to prevent damage due to water vapor or oxygen permeation into the devices, passivation layers have been introduced through methods such as sputtering, plasma enhanced chemical vapor deposition, and atomic layer chemical vapor deposition (ALCVD). In this work, the structural and chemical properties of Al2O3 films, deposited via ALCVD at relatively low temperatures of 109 degrees C, 200 degrees C, and 300 degrees C, are analyzed. In our experiment, trimethylaluminum (TMA) and H2O were used as precursors for Al2O3 film deposition via ALCVD. All of the Al2O3 films showed very smooth, featureless surfaces without notable defects. However, we found that the plastic flexible substrate of an OPV device passivated with 300 degrees C deposition temperature was partially bended and melted, indicating that passivation layers for OPV cells on plastic flexible substrates need to be formed at temperatures lower than 300 degrees C. The OPV cells on plastic flexible substrates were passivated by the Al2O3 film deposited at the temperature of 109 degrees C. Thereafter, the photovoltaic properties of passivated OPV cells were investigated as a function of exposure time under the atmosphere.

  9. Bio-mineralization and potential biogeochemical processes in bauxite deposits: genetic and ore quality significance

    Science.gov (United States)

    Laskou, Magdalini; Economou-Eliopoulos, Maria

    2013-08-01

    The Parnassos-Ghiona bauxite deposit in Greece of karst type is the 11th largest bauxite producer in the world. The mineralogical, major and trace-element contents and δ18O, δ12C, δ34S isotopic compositions of bauxite ores from this deposit and associated limestone provide valuable evidence for their origin and biogeochemical processes resulting in the beneficiation of low grade bauxite ores. The organic matter as thin coal layers, overlying the bauxite deposits, within limestone itself (negative δ12C isotopic values) and the negative δ34S values in sulfides within bauxite ores point to the existence of the appropriate circumstances for Fe bio-leaching and bio-mineralization. Furthermore, a consortium of microorganisms of varying morphological forms (filament-like and spherical to lenticular at an average size of 2 μm), either as fossils or presently living and producing enzymes, is a powerful factor to catalyze the redox reactions, expedite the rates of metal extraction and provide alternative pathways for metal leaching processes resulting in the beneficiation of bauxite ore.

  10. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    International Nuclear Information System (INIS)

    Maydannik, Philipp S.; Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C.; Söderlund, Mikko; Soininen, Pekka; Johansson, Petri; Kuusipalo, Jurkka; Moro, Lorenza; Zeng, Xianghui

    2014-01-01

    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al 2 O 3 diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al 2 O 3 films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument ( −4  g/m 2 day) for films coated at web moving speed of 0.25 m/min. Measurements using the Ca test indicated water vapor transmission rates ∼5 × 10 −6 g/m 2 day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate

  11. Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing

    Energy Technology Data Exchange (ETDEWEB)

    Ringleb, F.; Eylers, K.; Teubner, Th.; Boeck, T., E-mail: torsten.boeck@ikz-berlin.de [Leibniz-Institute for Crystal Growth, Max-Born-Straße 2, Berlin 12489 (Germany); Symietz, C.; Bonse, J.; Andree, S.; Krüger, J. [Bundesanstalt für Materialforschung und-prüfung (BAM), Unter den Eichen 87, Berlin 12205 (Germany); Heidmann, B.; Schmid, M. [Department of Physics, Freie Universität Berlin, Arnimalle 14, Berlin 14195 (Germany); Nanooptical Concepts for PV, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany); Lux-Steiner, M. [Nanooptical Concepts for PV, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany); Heterogeneous Material Systems, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany)

    2016-03-14

    A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD.

  12. Deposition of high Tc superconductor thin films by pulsed excimer laser ablation and their post-synthesis processing

    International Nuclear Information System (INIS)

    Ogale, S.B.

    1992-01-01

    This paper describes the use of pulsed excimer laser ablation technique for deposition of high quality superconductor thin films on different substrate materials such as Y stabilized ZrO 2 , SrTiO 3 , LiNbO 3 , Silicon and Stainless Steels, and dopant incorporation during the film depositions. Processing of deposited films using ion and laser beams for realisation of device features are presented. 28 refs., 16 figs

  13. Effect of Processing Parameters on Performance of Spray-Deposited Organic Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Jack W. Owen

    2011-01-01

    Full Text Available The performance of organic thin-film transistors (OTFTs is often strongly dependent on the fabrication procedure. In this study, we fabricate OTFTs of soluble small-molecule organic semiconductors by spray-deposition and explore the effect of processing parameters on film morphology and device mobility. In particular, we report on the effect of the nature of solvent, the pressure of the carrier gas used in deposition, and the spraying distance. We investigate the surface morphology using scanning force microscopy and show that the molecules pack along the π-stacking direction, which is the preferred charge transport direction. Our results demonstrate that we can tune the field-effect mobility of spray-deposited devices two orders of magnitude, from 10−3 cm2/Vs to 10−1 cm2/Vs, by controlling fabrication parameters.

  14. Rapid processing method for solution deposited YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dawley, J.T.; Clem, P.G.; Boyle, T.J.; Ottley, L.M.; Overmyer, D.L.; Siegal, M.P

    2004-02-01

    YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) films, deposited on buffered metal substrates, are the primary candidate for second-generation superconducting (SC) wires, with applications including expanded power grid transmission capability, compact motors, and enhanced sensitivity magnetic resonance imaging. Feasibility of manufacturing such superconducting wires is dependent on high processing speed, often a limitation of vapor and solution-based YBCO deposition processes. In this work, YBCO films were fabricated via a new diethanolamine-modified trifluoroacetic film solution deposition method. Modifying the copper chemistry of the YBCO precursor solution with diethanolamine enables a hundredfold decrease in the organic pyrolysis time required for MA/cm{sup 2} current density (J{sub c}) YBCO films, from multiple hours to {approx}20 s in atmospheric pressure air. High quality, {approx}0.2 {mu}m thick YBCO films with J{sub c} (77 K) values {>=}2 MA/cm{sup 2} at 77 K are routinely crystallized from these rapidly pyrolyzed films deposited on LaAlO{sub 3}. This process has also enabled J{sub c} (77 K)=1.1 MA/cm{sup 2} YBCO films via 90 m/h dip-coating on Oak Ridge National Laboratory RABiTS textured metal tape substrates. This new YBCO solution deposition method suggests a route toward inexpensive and commercializable {approx}$10/kA m solution deposited YBCO coated conductor wires.

  15. Constituents’ formal participation in the IASB’s due process: New insights into the impact of country and due process document characteristics

    Directory of Open Access Journals (Sweden)

    Michael Dobler

    2016-09-01

    Full Text Available This paper adopts a multi-issue/multi-period approach to provide new insights into key determinants of constituents’ formal participation in the due process of the International Accounting Standards Board (IASB. Based on an analysis of 8,825 comment letters submitted during the period 2006–2012, we find imbalances in the representation of constituents. Multiple regressions reveal that among various economic and cultural variables equity market capitalization and the society’s level of individualism are the key drivers of the country-level of constituents’ participation, and each variable has explanatory power over the other. The level of constituents’ participation is positively associated with the number of input opportunities offered by a due process document but unrelated to the complexity of a standard-setting project. The results are robust across various sub-samples and to additional sensitivity tests. Our findings indicate threats to the input legitimacy of the IASB and suggest avenues to stimulate constituents’ participation.

  16. Fundamental Mechanisms of Roughening and Smoothing During Thin Film Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Headrick, Randall [Univ. of Vermont, Burlington, VT (United States)

    2016-03-18

    In this research program, we have explored the fundamental limits for thin film deposition in both crystalline and amorphous (i.e. non-crystalline) materials systems. For vacuum-based physical deposition processes such as sputter deposition, the background gas pressure of the inert gas (usually argon) used as the process gas has been found to be a key variable. Both a roughness transition and stress transition as a function of pressure have been linked to a common mechanism involving collisions of energetic particles from the deposition source with the process inert gas. As energetic particles collide with gas molecules in the deposition process they lose their energy rapidly if the pressure (and background gas density) is above a critical value. Both roughness and stress limit important properties of thin films for applications. In the area of epitaxial growth we have also discovered a related effect; there is a critical pressure below which highly crystalline layers grow in a layer-by-layer mode. This effect is also though to be due to energetic particle thermalization and scattering. Several other important effects such as the observation of coalescence dominated growth has been observed. This mode can be likened to the behavior of two-dimensional water droplets on the hood of a car during a rain storm; as the droplets grow and touch each other they tend to coalesce rapidly into new larger circular puddles, and this process proceeds exponentially as larger puddles overtake smaller ones and also merge with other large puddles. This discovery will enable more accurate simulations and modeling of epitaxial growth processes. We have also observed that epitaxial films undergo a roughening transition as a function of thickness, which is attributed to strain induced by the crystalline lattice mismatch with the substrate crystal. In addition, we have studied another physical deposition process called pulsed laser deposition. It differs from sputter deposition due to the

  17. Low-pressure chemical vapor deposition as a tool for deposition of thin film battery materials

    NARCIS (Netherlands)

    Oudenhoven, J.F.M.; Dongen, van T.; Niessen, R.A.H.; Croon, de M.H.J.M.; Notten, P.H.L.

    2009-01-01

    Low Pressure Chemical Vapor Deposition was utilized for the deposition of LiCoO2 cathode materials for all-solid-state thin-film micro-batteries. To obtain insight in the deposition process, the most important process parameters were optimized for the deposition of crystalline electrode films on

  18. Effects of vacuum processing erbium dideuteride/ditritide films deposited on chromium underlays on copper substrates

    International Nuclear Information System (INIS)

    Provo, J.L.

    1978-01-01

    Thin films of erbium dideuteride/ditritide were experimentally produced on chromium underlays deposited on copper substrates. The chromium underlay is required to prevent erbium occluder/copper substrate alloying which inhibits hydriding. Data taken has shown that vacuum processing affects the erbium/chromium/copper interaction. With an in situ process in which underlay/occluder films are vacuum deposited onto copper substrates and hydrided with no air exposure between these steps, data indicates a minimum of 1500A of chromium is required for optimum hydriding. If films are vacuum deposited as above and air-exposed before hydriding, a minimum of 3000A of chromium was shown to be required for equivalent hydriding. Data suggests that the activation step (600 0 C for 1 hour) required for hydriding the film of the second type is responsible for the difference observed. Such underlay thickness parameters are important, with regard to heat transfer considerations in thin hydride targets used for neutron generation

  19. Smooth germanium nanowires prepared by a hydrothermal deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei1977@163.com [School of Materials Science and Engineering, Institute of Molecular Engineering and Applied Chemistry, Key Laboratory of Materials Science and Processing of Anhui Province, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Zhao, H.S. [School of Materials Science and Engineering, Institute of Molecular Engineering and Applied Chemistry, Key Laboratory of Materials Science and Processing of Anhui Province, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Tan, W. [Henkel Huawei Electronics Co. Ltd., Lian' yungang, Jiangsu 222006 (China); Yu, H.Y. [School of Materials Science and Engineering, Institute of Molecular Engineering and Applied Chemistry, Key Laboratory of Materials Science and Processing of Anhui Province, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Chen, Y.W. [Department of Materials Science, Fudan University, Shanghai 200433 (China); Fan, C.G. [School of Materials Science and Engineering, Institute of Molecular Engineering and Applied Chemistry, Key Laboratory of Materials Science and Processing of Anhui Province, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Zhang, Qian-Feng, E-mail: zhangqf@ahut.edu.cn [School of Materials Science and Engineering, Institute of Molecular Engineering and Applied Chemistry, Key Laboratory of Materials Science and Processing of Anhui Province, Anhui University of Technology, Ma' anshan, Anhui 243002 (China)

    2009-11-15

    Smooth germanium nanowires were prepared using Ge and GeO{sub 2} as the starting materials and Cu sheet as the substrate by a simple hydrothermal deposition process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations show that the germanium nanowires are smooth and straight with uniform diameter of about 150 nm in average and tens of micrometers in length. X-ray diffraction (XRD) and Raman spectrum of the germanium nanowires display that the germanium nanowires are mainly composed of cubic diamond phase. PL spectrum shows a strong blue light emission at 441 nm. The growth mechanism is also discussed.

  20. Smooth germanium nanowires prepared by a hydrothermal deposition process

    International Nuclear Information System (INIS)

    Pei, L.Z.; Zhao, H.S.; Tan, W.; Yu, H.Y.; Chen, Y.W.; Fan, C.G.; Zhang, Qian-Feng

    2009-01-01

    Smooth germanium nanowires were prepared using Ge and GeO 2 as the starting materials and Cu sheet as the substrate by a simple hydrothermal deposition process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations show that the germanium nanowires are smooth and straight with uniform diameter of about 150 nm in average and tens of micrometers in length. X-ray diffraction (XRD) and Raman spectrum of the germanium nanowires display that the germanium nanowires are mainly composed of cubic diamond phase. PL spectrum shows a strong blue light emission at 441 nm. The growth mechanism is also discussed.

  1. Evidence for substantial forestry canopy processing of nitrogen deposition using isotopic tracer experiments in low deposition conditions

    Science.gov (United States)

    Ferraretto, Daniele; Heal, Kate

    2017-04-01

    Temperate forest ecosystems are significant sinks for nitrogen deposition (Ndep) yielding benefits such as protection of waterbodies from eutrophication and enhanced sequestration of atmospheric CO2. Previous studies have shown evidence of biological nitrification and Ndep processing and retention in forest canopies. However, this was reported only at sites with high environmental or experimentally enhanced rates of Ndep (˜18 kg N ha-1 y-1) and has not yet been demonstrated in low Ndep environments. We have used bulk field hydrochemical measurements and labelled isotopic experiments to assess canopy processing in a lower Ndep environment (˜7 kg N ha-1 year-1) at a Sitka spruce plantation in Perthshire, Scotland, representing the dominant tree species (24%) in woodlands in Great Britain. Analysis of 4.5 years of measured N fluxes in rainfall (RF) and fogwater onto the canopy and throughfall (TF) and stemflow (SF) below the canopy suggests strong transformation and uptake of Ndep in the forest canopy. Annual canopy Ndep uptake was ˜4.7 kg N ha-1 year-1, representing 60-76% of annual Ndep. To validate these plot-scale results and track N uptake within the forest canopy in different seasons, double 15N-labelled NH4NO3 (98%) solution was sprayed in summer and winter onto the canopy of three trees at the measurement site. RF, TF and SF samples have been collected and analysed for 15NH4 and 15NO3. Comparing the amount of labelled N recovered under the sample trees with the measured δ15N signal is expected to provide further evidence of the role of forest canopies in actively processing and retaining atmospheric N deposition.

  2. Teaching about Due Process of Law. ERIC Digest.

    Science.gov (United States)

    Vontz, Thomas S.

    Fundamental constitutional and legal principles are central to effective instruction in the K-12 social studies curriculum. To become competent citizens, students need to develop an understanding of the principles on which their society and government are based. Few principles are as important in the social studies curriculum as due process of…

  3. Geological principles of exploration for sandstone-hosted uranium deposits

    International Nuclear Information System (INIS)

    Le Roux, J.P.

    1982-10-01

    Although the importance of sandstone-hosted uranium deposits has seemingly faded in recent years due to the discovery of large, high -grade deposits elsewhere, a forecasted energy shortage in the near future will probably necessitate a new look at sedimentary basins as a source of uranium. Back-arc basins adjacent to calcalkaline source areas are especially favourable if they are filled with fluvial, post-Devonian sediments. Syn- and post-depositional tectonics play an important role in the sedimentation-mineralisation process and should be investigated. The oxidation-reduction state of the sandstones is a valid prospecting tool. Sedimentological environments govern the permeability and vegetal matter content of sandstones and directly control uranium mineralisation

  4. Study on the electrical properties of ITO films deposited by facing target sputter deposition

    International Nuclear Information System (INIS)

    Kim, Youn J; Jin, Su B; Kim, Sung I; Choi, Yoon S; Choi, In S; Han, Jeon G

    2009-01-01

    This study examined the mechanism for the change in the electrical properties (carrier concentration (n) and mobility (μ)) of tin-doped indium oxide (ITO) films deposited by magnetron sputtering in a confined facing magnetic field. The relationship between the carrier concentration and the mobility was significantly different from the results reported for ITO films deposited by other magnetron sputtering processes. The lowest resistivity obtained for ITO films deposited in a confined facing magnetic field at low substrate temperatures (approximately 120 0 C) was 4.26 x 10 -4 Ω cm at a power density of 3 W cm -2 . Crystalline ITO films were obtained at a low power density range from 3 to 5 W cm -2 due to the increase in the substrate temperature from 120 to 162 0 C. This contributed to the increased carrier concentration and decreased electrical resistivity. X-ray photoelectron spectroscopy revealed an increase in the concentration of the Sn 4+ states. This was attributed to the formation of a crystalline ITO film, which effectively enhanced the carrier concentration and reduced the carrier mobility.

  5. PbS Thin Films for Photovoltaic Applications Obtained by Non-Traditional Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Pérez-García Claudia Elena

    2015-01-01

    Full Text Available To optimize cost-efficiency relation for thin film solar cells, we explore the recently developed versions of chemical deposition of semiconductor films, together with classic CBD (Chemical Bath Deposition: SILAR (Successive Ionic Layer Adsorption and Reaction and PCBD (Photo Chemical Bath Deposition, all of them ammonia-free and ecologically friendly. The films of CdS and PbS were made, and experimental solar cells with CdS window layer and PbS absorber elaborated. We found that band gap of PbS films can be monitored by deposition process due to porosity-induced quantum confinement which depends on the parameters of the process. We expect that the techniques employed can be successfully used for production of optoelectronic devices.

  6. New deposition processes for the growth of oxide and nitride thin films

    International Nuclear Information System (INIS)

    Apen, E.A.; Atagi, L.M.; Barbero, R.S.; Espinoza, B.F.; Hubbard, K.M.; Salazar, K.V.; Samuels, J.A.; Smith, D.C.; Hoffman, D.M.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this effort is to study the use of homoleptic metal amido compounds as precursors for chemical vapor deposition (CVD). The amides offer potential for the deposition of a variety of important materials at low temperatures. The establishment of these precursor compounds will enhance the ability to exploit the properties of advanced materials in numerous coatings applications. Experiments were performed to study the reactivity of Sn[NMe 2 ] 4 with oxygen. The data demonstrated that gas-phase insertion of oxygen into the Sn-N bond, leading to a reactive intermediate, plays an important role in tin oxide deposition. Several CVD processes for technologically important materials were developed using the amido precursor complexes. These included the plasma enhanced CVD of TiN and Zr 3 N 4 , and the thermal CVD of GaN and AlN. Quality films were obtained in each case, demonstrating the potential of the amido compounds as CVD precursors

  7. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    Energy Technology Data Exchange (ETDEWEB)

    Maydannik, Philipp S., E-mail: philipp.maydannik@lut.fi; Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C. [Advanced Surface Technology Research Laboratory, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Söderlund, Mikko; Soininen, Pekka [Beneq Oy, P.O. Box 262, 01511 Vantaa (Finland); Johansson, Petri; Kuusipalo, Jurkka [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 589, 33101 Tampere (Finland); Moro, Lorenza; Zeng, Xianghui [Samsung Cheil Industries, San Jose R and D Center, 2186 Bering Drive, San Jose, California 95131 (United States)

    2014-09-01

    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al{sub 2}O{sub 3} diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al{sub 2}O{sub 3} films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument (<5 × 10{sup −4} g/m{sup 2} day) for films coated at web moving speed of 0.25 m/min. Measurements using the Ca test indicated water vapor transmission rates ∼5 × 10{sup −6} g/m{sup 2} day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate.

  8. Process optimization of atomized melt deposition for the production of dispersion strengthened Al-8.5%Fe-1.2%V-1.7%Si alloys

    International Nuclear Information System (INIS)

    Hariprasad, S.; Sastry, S.M.L.; Jerina, K.L.

    1995-01-01

    Atomized melt deposition is a low cost manufacturing process with the microstructural control achieved through rapid solidification. In this process the liquid metal is disintegrated into fine droplets by gas atomization and the droplets are deposited on a substrate producing near net shape products. In the present investigation Al-8.5%Fe-1.2%V-1.7%Si alloy was produced using atomized melt deposition process to study the evolution of microstructure and assess the cooling rates and the undercooling achieved during the process. The size, morphology and the composition of second phase particles in the alloy are strong functions of the cooling rate and the undercooling and hence microstructural changes with the variation in process parameters were quantified. To define optimum conditions for the atomized melt deposition process, a mathematical model was developed. The model determines the temperature distribution of the liquid droplets during gas atomization and during the deposition stages. The model predicts the velocity distribution, cooling rates and the fraction solid, during the flight for different droplet sizes. The solidification heat transfer phenomena taking place during the atomized melt deposition process was analyzed using a finite difference method based on the enthalpy formulation

  9. Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning

    Directory of Open Access Journals (Sweden)

    Fabrizia Caiazzo

    2018-03-01

    Full Text Available Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace.

  10. Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning.

    Science.gov (United States)

    Caiazzo, Fabrizia; Caggiano, Alessandra

    2018-03-19

    Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace.

  11. Natural analogue study of uranium deposits in Japan with special reference to the Tono uranium deposit

    International Nuclear Information System (INIS)

    Komuro, Kosei; Sasao, Eiji

    2004-05-01

    In order to verify the safety assessment for geological disposal system of high-level radioactive waste, it is necessary to evaluate properly the stability of the disposal system under natural hydrogeological environment over long period of time (ten to hundred thousands years). For the safety assessment for that in the Japanese Islands, many geological processes inherent in the tectonically active Island-Arc system should be also taken into consideration in addition to those in stable continental environment. However, it is difficult because some processes such as earthquake seem to be accidental and some are periodic or gradual over our life scale. The uranium deposits in Japan are subjected to many geological processes inherent in the tectonically active Island-Arc system. The studies on long-term preservation of uranium deposits in Japan from a natural analogue viewpoint would be expected to provide useful information for the assessment in the Japanese Islands over long period of time. In order to understand the behavior of radionuclides under natural hydrogeological environment in Japanese Islands over long period of time, the uranium deposits in Japan, especially of the Tono uranium deposit was investigated from a natural analogue viewpoint under the course of joint research program by University of Tsukuba and Japan Nuclear Cycle Development Institute. Important conclusions obtained in the present study are summarized as follows: The migration behavior of the radionuclides in the granite area is mainly controlled by the stability of original minerals in oxic condition, being due to poor reducing agents such as organic matter and sulfide minerals. In the case of hydrothermal alteration, yttrialite and fergusonite were decomposed and thorogummite was formed at the altered part, whereas zircon and allanite have not been significantly altered. In the case of weathering, autunite and torbernite were formed, probably due to the high phosphorus weathering

  12. Plasma processes and film growth of expanding thermal plasma deposited textured zinc oxide

    NARCIS (Netherlands)

    Groenen, R.; Linden, J.L.; Sanden, van de M.C.M.

    2005-01-01

    Plasma processes and film growth of textured zinc oxide deposited from oxygen and diethyl zinc utilizing expanding thermal argon plasma created by a cascaded arc is discussed. In all conditions explored, an excess of argon ions and low temperature electrons is available, which represent the

  13. Plasma-assisted ALD for the conformal deposition of SiO2 : process, material and electronic properties

    NARCIS (Netherlands)

    Dingemans, G.; Helvoirt, van C.A.A.; Pierreux, D.; Keuning, W.; Kessels, W.M.M.

    2012-01-01

    Plasma-assisted atomic layer deposition (ALD) was used to deposit SiO2 films in the temperature range of Tdep = 50–400°C on Si(100). H2Si[N(C2H5)2]2 and an O2 plasma were used as Si precursor and oxidant, respectively. The ALD growth process and material properties were characterized in detail.

  14. Sedimentary facies and Holocene depositional processes of Laura Island, Majuro Atoll

    Science.gov (United States)

    Yasukochi, Toru; Kayanne, Hajime; Yamaguchi, Toru; Yamano, Hiroya

    2014-10-01

    The depositional processes that formed Laura Island, Majuro Atoll, Marshall Islands, were reconstructed based on a facies analysis of island sediments and spine ratios, and radiocarbon ages of foraminifera. Sedimentary facies were analyzed from trenches and drill cores excavated on the island and its adjacent reef flat. Depositional ages were obtained using benthic foraminifera (Calcarina) whose spines had not been abraded. The facies were classified into two types: gravelly and sandy. The initial sediments of these sites consisted of gravelly facies in the lower horizon and sandy facies in the upper horizon. Their ages were approximately 2000 cal BP and coincident with the onset of a 1.1-m decline in regional relative sea level, which enabled deposition of the gravelly facies. Half of the sand fraction of the sediment was composed of larger benthic foraminifera. The spine ratio showed that their supply source on the reef flat was located oceanside of the island. The supply source appears to have been caused by the relative sea-level fall. This indicates that the studied island was formed by a relative reduction in wave energy and enhanced foraminiferal supply, both of which were triggered by the late Holocene relative sea-level fall.

  15. Difference in inhaled aerosol deposition patterns in the lungs due to three different sized aerosols

    International Nuclear Information System (INIS)

    Miki, M.; Isawa, T.; Teshima, T.; Anazawa, Y.; Motomiya, M.

    1992-01-01

    Deposition patterns of inhaled aerosol in the lungs were studied in five normal subjects and 20 patients with lung disease by inhaling radioaerosols with three different particle size distributions. Particle size distributions were 0.84, 1.04 and 1.93 μm in activity median aerodynamic diameter (AMAD) with its geometric standard deviation (σg) of 1.73, 1.71 and 1.52, respectively. Deposition patterns of inhaled aerosols were compared qualitatively and quantitatively by studying six different parameters: alveolar deposition ratio (ALDR), X max , X mean , standard deviation (S.D.), skewness and kurtosis of the radioactive distribution in the lungs following inhalation. It has been found that aerosol deposition patterns varied with particle size. The unevenness of aerosol deposition, X max , X mean and the number of 'hot spots' became more prominent with increase in particle size, whereas values of ALDR and S.D. decreased as particle size increased. (author)

  16. Changes in erosional and depositional processes with time and management of Goa Coast, central west coast of India

    Science.gov (United States)

    Nayak, Ganapati; D'Souza, Joseph

    2010-05-01

    with seasonal morphological changes and annual cyclicity. The coastal zone in Goa is exposed to environmental and anthropogenic pressures. Some of the factors attributing to these pressures can be due to demographic settings and population growth, rapid urbanization, migration, recreation and tourism activities, fishery activities, transportation problems, socio-economic shift and transformation in occupation like, fishing, tourism, trade, salt industry; wetlands conversion, degradation of agriculture land and fallow lands. Shoreline changes observed overlapping the data after 32 years showed that all along the coast of Goa, from north to south, there is large variation in depositional and erosional processes. Deposition is specifically observed at Morjim, Baga, Campal, Miramar, Mobor and erosion is specifically observed at Kerim, Anjuna, Velsao. The present study reveals that all along the estuarine systems, there is net deposition. Further change detection study carried out overlapping the data after 38 years showed transformation of Khazan lands, conversion of marshy swampy and water logged areas, increase in Mangrove areas and decrease in salt pans. The present paper has succeeded in delineating various coastal ecosystems, coastal land forms, their resource potentials and transformation, if any. The study has helped earmarking the coastal region into conservation, development and utilization areas.

  17. Tuning polymorphism and orientation in organic semiconductor thin films via post-deposition processing.

    Science.gov (United States)

    Hiszpanski, Anna M; Baur, Robin M; Kim, Bumjung; Tremblay, Noah J; Nuckolls, Colin; Woll, Arthur R; Loo, Yueh-Lin

    2014-11-05

    Though both the crystal structure and molecular orientation of organic semiconductors are known to impact charge transport in thin-film devices, separately accessing different polymorphs and varying the out-of-plane molecular orientation is challenging, typically requiring stringent control over film deposition conditions, film thickness, and substrate chemistry. Here we demonstrate independent tuning of the crystalline polymorph and molecular orientation in thin films of contorted hexabenzocoronene, c-HBC, during post-deposition processing without the need to adjust deposition conditions. Three polymorphs are observed, two of which have not been previously reported. Using our ability to independently tune the crystal structure and out-of-plane molecular orientation in thin films of c-HBC, we have decoupled and evaluated the effects that molecular packing and orientation have on device performance in thin-film transistors (TFTs). In the case of TFTs comprising c-HBC, polymorphism and molecular orientation are equally important; independently changing either one affects the field-effect mobility by an order of magnitude.

  18. Modeling of thermal, electronic, hydrodynamic, and dynamic deposition processes for pulsed-laser deposition of thin films

    International Nuclear Information System (INIS)

    Liu, C.L.; LeBoeuf, J.N.; Wood, R.F.; Geohegan, D.B.; Donato, J.M.; Chen, K.R.; Puretzky, A.A.

    1994-11-01

    Various physical processes during laser ablation of solids for pulsed-laser deposition (PLD) are studied using a variety of computational techniques. In the course of the authors combined theoretical and experimental effort, they have been trying to work on as many aspects of PLD processes as possible, but with special focus on the following areas: (a) the effects of collisional interactions between the particles in the plume and in the background on the evolving flow field and on thin film growth, (b) interactions between the energetic particles and the growing thin films and their effects on film quality, (c) rapid phase transformations through the liquid and vapor phases under possibly nonequilibrium thermodynamic conditions induced by laser-solid interactions, (d) breakdown of the vapor into a plasma in the early stages of ablation through both electronic and photoionization processes, (c) hydrodynamic behavior of the vapor/plasma during and after ablation. The computational techniques used include finite difference (FD) methods, particle-in-cell model, and atomistic simulations using molecular dynamics (MD) techniques

  19. Achieving uniform layer deposition by atmospheric-pressure plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Ok [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Kang, Woo Seok, E-mail: kang@kimm.re.kr [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of); Hur, Min; Lee, Jin Young [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Song, Young-Hoon [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2015-12-31

    This work investigates the use of plasma-enhanced chemical vapor deposition under atmospheric pressure for achieving uniform layer formation. Electrical and optical measurements demonstrated that the counterbalance between oxygen and precursors maintained the homogeneous discharge mode, while creating intermediate species for layer deposition. Several steps of the deposition process of the layers, which were processed on a stationary stage, were affected by flow stream and precursor depletion. This study showed that by changing the flow streamlines using substrate stage motion uniform layer deposition under atmospheric pressure can be achieved. - Highlights: • Zirconium oxide was deposited by atmospheric-pressure plasma-enhanced chemical vapor deposition. • Homogeneous plasma was maintained by counterbalancing between discharge gas and precursors. • Several deposition steps were observed affected by the gas flow stream and precursor depletion. • Thin film layer was uniformly grown when the substrate underwent a sweeping motion.

  20. Synthesizing the Nanocrytalline Cobalt-Iron Coating Through The Electrodeposition Process With Different Time Deposition

    Science.gov (United States)

    Rozlin Nik Masdek, Nik; Sorfian Hafiz Mansor, Mohd; Salleh, Zuraidah; Hyie, Koay Mei

    2018-03-01

    In the engineering world, electrodeposition or electroplating has become the most popular method of surface coating in improving corrosion behavior and mechanical properties of material. Therefore in this study, CoFe nanoparticle protective coating has been synthesized on the mild steel washer using electrodeposition method. The electrodeposition was conducted in the acidic environment with the pH value range from 1 to 2 with the controlled temperature of 50°C. The influence of deposition time (30, 60, 90 minutes) towards characteristic and properties such as particle size, surface morphology, corrosion behavior, and microhardness were studied in this investigation. Several results can be obtained by doing this experiment and testing. First, the surface morphology of Cobalt Iron (CoFe) on the electrodeposited mild steel washer are obtained. In addition, the microhardness of the mild steel washer due to the different deposition time are determined. Next, the observation on the difference in the grain size of CoFe that has been electrodeposited on the mild steel plate is made. Last but not least, the corrosion behavior was investigated. CoFe nanoparticles deposited for 30 minutes produced the smallest particle size and the highest microhardness of 86.17 and 236.84 HV respectively. The CoFe nanoparticles also exhibit the slowest corrosion rate at 30 minutes as compared to others. The crystalline size also increases when the time deposition is increased. The sample with 30 minute depositon time indicate the smallest crystalline size which is 15nm. The decrement of deposition time plays an important role in synthesizing CoFe nanoparticles with good corrosion resistance and microhardness. CoFe nanoparticles obtained at 30 minutes shows high corrosion resistance compared to others. In a nutshell, it was observed that the decrement of deposition time improved mechanical and corrosion properties of CoFe nanoparticles.

  1. Hideout in steam generator tube deposits

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W.

    1998-05-01

    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m 2 , corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10 3 . Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  2. Low pressure plasma spray deposition of W-Ni-Fe alloy

    International Nuclear Information System (INIS)

    Mutasim, Z.Z.; Smith, R.W.

    1991-01-01

    The production of net shape refractory metal structural preforms are increasing in importance in chemical processing, defense and aerospace applications. Conventional methods become limited for refractory metal processing due to the high melting temperatures and fabrication difficulties. Plasma spray forming, a high temperature process, has been shown to be capable of refractory metal powder consolidation in net shape products. The research reported here has evaluated this method for the deposition of heavy tungsten alloys. Plasma Melted Rapidly Solidified (PMRS) W 8%Ni-2%Fe refractory metal powders were spray formed using vacuum plasma spray (VPS) process and produced 99% dense, fine grain and homogeneous microstructures. In this paper plasma operating parameters (plasma arc gas type and flowrate plasma gun nozzle size and spray distance) were studied and their effects on deposit's density and microstructure are reported

  3. Electrochemical Deposition of Aluminum from NaCl-AlCl3 Melts

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, H. A.; Berg, Rolf W.

    1990-01-01

    Electrochemical deposition of aluminum from NaAlCl4 melts saturated with NaCl onto a glassy carbon electrode at175°C has been studied by voltammetry, chronoamperometry, and constant current deposition. The deposition of aluminumwas found to proceed via a nucleation/growth mechanism, and the nucle......Electrochemical deposition of aluminum from NaAlCl4 melts saturated with NaCl onto a glassy carbon electrode at175°C has been studied by voltammetry, chronoamperometry, and constant current deposition. The deposition of aluminumwas found to proceed via a nucleation/growth mechanism......, and the nucleation process was found to be progressive.The morphology of aluminum deposits was examined with photomicroscopy. It was shown that depending on the currentdensities (c.d.) applied, three types of aluminum deposits could be obtained, namely, spongy deposits formed at lower c.d.(below 0.7 mA/cm2), smooth...... layers deposited at intermediate c.d. (between 2 and 10 mA/cm2), and dendritic or porous depositsobtained at high c.d. (above 15 mA/cm2). However, the smooth aluminum deposits were about five times more voluminousthan the theoretical value. The spongy deposits were formed due to difficulties...

  4. Ellipsometry study of process deposition of amorphous Indium Gallium Zinc Oxide sputtered thin films

    International Nuclear Information System (INIS)

    Talagrand, C.; Boddaert, X.; Selmeczi, D.G.; Defranoux, C.; Collot, P.

    2015-01-01

    This paper reports on an InGaZnO optical study by spectrometric ellipsometry. First of all, the fitting results of different models and different structures are analysed to choose the most appropriate model. The Tauc–Lorentz model is suitable for thickness measurements but a more complex model allows the refractive index and extinction coefficient to be extracted more accurately. Secondly, different InGaZnO process depositions are carried out in order to investigate stability, influence of deposition time and uniformity. Films present satisfactory optical stability over time. InGaZnO optical property evolution as a function of deposition time is related to an increase in temperature. To understand the behaviour of uniformity, mapping measurements are correlated to thin film resistivity. Results show that temperature and resputtering are the two phenomena that affect IGZO uniformity. - Highlights: • Model and structure are investigated to fit IGZO ellipsometric angles. • Maximum refractive index rises with substrate temperature and thus deposition time. • Resputtering leads to inhomogeneity in IGZO electrical and optical properties

  5. Ellipsometry study of process deposition of amorphous Indium Gallium Zinc Oxide sputtered thin films

    Energy Technology Data Exchange (ETDEWEB)

    Talagrand, C., E-mail: talagrand@emse.fr [Ecole des Mines de Saint-Etienne CMP-GC, Dept PS2, Gardanne, 880 route de Mimet (France); Boddaert, X. [Ecole des Mines de Saint-Etienne CMP-GC, Dept PS2, Gardanne, 880 route de Mimet (France); Selmeczi, D.G.; Defranoux, C. [Semilab Semiconductor Physics Laboratory Co. Ltd., Budapest, 1117 (Hungary); Collot, P. [Ecole Nationale Supérieure d' Arts et Métiers ParisTech, Aix-en-Provence, 2 cours des Arts et Métiers (France)

    2015-09-01

    This paper reports on an InGaZnO optical study by spectrometric ellipsometry. First of all, the fitting results of different models and different structures are analysed to choose the most appropriate model. The Tauc–Lorentz model is suitable for thickness measurements but a more complex model allows the refractive index and extinction coefficient to be extracted more accurately. Secondly, different InGaZnO process depositions are carried out in order to investigate stability, influence of deposition time and uniformity. Films present satisfactory optical stability over time. InGaZnO optical property evolution as a function of deposition time is related to an increase in temperature. To understand the behaviour of uniformity, mapping measurements are correlated to thin film resistivity. Results show that temperature and resputtering are the two phenomena that affect IGZO uniformity. - Highlights: • Model and structure are investigated to fit IGZO ellipsometric angles. • Maximum refractive index rises with substrate temperature and thus deposition time. • Resputtering leads to inhomogeneity in IGZO electrical and optical properties.

  6. Disruption of tephra fall deposits caused by lava flows during basaltic eruptions

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2015-10-01

    Observations in the USA, Iceland and Tenerife, Canary Islands reveal how processes occurring during basaltic eruptions can result in complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents. Observations illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter sheet-form fall deposits. Complexity arises through synchronous and alternating effusive and explosive activity that results in intercalated lavas and tephra deposits. Tephra deposits can become disrupted into mounds and ridges by lateral and vertical displacement caused by movement (including inflation) of underlying pāhoehoe lavas and clastogenic lavas. Mounds of tephra can be rafted away over distances of 100 s to 1,000 s m from proximal pyroclastic constructs on top of lava flows. Draping of irregular topography by fall deposits and subsequent partial burial of topographic depressions by later lavas can result in apparent complexity of tephra layers. These processes, deduced from field relationships, have resulted in considerable stratigraphic complexity in the studied proximal regions where fallout was synchronous or alternated with inflation of subjacent lava sheets. These mechanisms may lead to diachronous contact relationships between fall deposits and lava flows. Such complexities may remain cryptic due to textural and geochemical quasi-homogeneity within sequences of interbedded basaltic fall deposits and lavas. The net effect of these processes may be to reduce the usefulness of data collected from proximal fall deposits for reconstructing basaltic eruption dynamics.

  7. Bioactive glass-ceramic coatings prepared by pulsed laser deposition from RKKP targets (sol-gel vs melt-processing route)

    Energy Technology Data Exchange (ETDEWEB)

    Rau, J.V., E-mail: giulietta.rau@ism.cnr.it [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Teghil, R. [Universita della Basilicata, Dipartimento di Chimica ' A.M. Tamburro' , Via dell' Ateneo Lucano, 10-85100 Potenza (Italy); CNR-IMIP U.O.S. di Potenza, Zona Industriale di Tito scalo (PZ) (Italy); Fosca, M. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Universita di Roma ' La Sapienza' , Dipartimento di Chimica, Piazzale Aldo Moro, 5-00185 Rome (Italy); De Bonis, A. [Universita della Basilicata, Dipartimento di Chimica ' A.M. Tamburro' , Via dell' Ateneo Lucano, 10-85100 Potenza (Italy); CNR-IMIP U.O.S. di Potenza, Zona Industriale di Tito scalo (PZ) (Italy); Cacciotti, I.; Bianco, A. [Universita di Roma ' Tor Vergata' , Dipartimento di Ingegneria Industriale, UR INSTM ' Roma Tor Vergata' , Via del Politecnico, 1-00133 Rome (Italy); Albertini, V. Rossi [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Caminiti, R. [Universita di Roma ' La Sapienza' , Dipartimento di Chimica, Piazzale Aldo Moro, 5-00185 Rome (Italy); Ravaglioli, A. [Parco Torricelli delle Arti e delle Scienze, Via Granarolo, 64-48018 Faenza (Ra) (Italy)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Bioactive glass-ceramic coatings for bone tissue repair and regeneration. Black-Right-Pointing-Pointer Pulsed Lased Deposition allowed congruent transfer of target composition to coating. Black-Right-Pointing-Pointer Target was prepared by sol-gel process suitable for compositional tailoring. Black-Right-Pointing-Pointer Titanium, widely used for orthopaedics and dental implants, was used as substrate. Black-Right-Pointing-Pointer The physico-chemical properties of the prepared coatings are reported. -- Abstract: The deposition of innovative glass-ceramic composition (i.e. RKKP) coatings by Pulsed Lased Deposition (PLD) technique is reported. RKKP was synthesised following two methodologies: melt-processing and sol-gel, the latter being particularly suitable to tailor the compositional range. The PLD advantage with respect to other deposition techniques is the congruent transfer of the target composition to the coating. The physico-chemical properties of films were investigated by Scanning Electron and Atomic Force Microscopies, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, and Vickers microhardness. The deposition performed at 12 J/cm{sup 2} and 500 Degree-Sign C allows to prepare crystalline films with the composition that replicates rather well that of the initial targets. The 0.6 {mu}m thin melt-processing RKKP films, possessing the hardness of 25 GPa, and the 4.3 {mu}m thick sol-gel films with the hardness of 17 GPa were obtained.

  8. Bioactive glass–ceramic coatings prepared by pulsed laser deposition from RKKP targets (sol–gel vs melt-processing route)

    International Nuclear Information System (INIS)

    Rau, J.V.; Teghil, R.; Fosca, M.; De Bonis, A.; Cacciotti, I.; Bianco, A.; Albertini, V. Rossi; Caminiti, R.; Ravaglioli, A.

    2012-01-01

    Highlights: ► Bioactive glass–ceramic coatings for bone tissue repair and regeneration. ► Pulsed Lased Deposition allowed congruent transfer of target composition to coating. ► Target was prepared by sol–gel process suitable for compositional tailoring. ► Titanium, widely used for orthopaedics and dental implants, was used as substrate. ► The physico-chemical properties of the prepared coatings are reported. -- Abstract: The deposition of innovative glass–ceramic composition (i.e. RKKP) coatings by Pulsed Lased Deposition (PLD) technique is reported. RKKP was synthesised following two methodologies: melt-processing and sol–gel, the latter being particularly suitable to tailor the compositional range. The PLD advantage with respect to other deposition techniques is the congruent transfer of the target composition to the coating. The physico-chemical properties of films were investigated by Scanning Electron and Atomic Force Microscopies, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, and Vickers microhardness. The deposition performed at 12 J/cm 2 and 500 °C allows to prepare crystalline films with the composition that replicates rather well that of the initial targets. The 0.6 μm thin melt-processing RKKP films, possessing the hardness of 25 GPa, and the 4.3 μm thick sol–gel films with the hardness of 17 GPa were obtained.

  9. Deposition of antimony telluride thin film by ECALE

    Institute of Scientific and Technical Information of China (English)

    GAO; Xianhui; YANG; Junyou; ZHU; Wen; HOU; Jie; BAO; Siqian; FAN; Xi'an; DUAN; Xingkai

    2006-01-01

    The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.

  10. Application of heat treatment and dispersive strengthening concept in interlayer deposition to enhance diamond film adherence

    Energy Technology Data Exchange (ETDEWEB)

    Lin Chiiruey [Tatung Inst. of Technol., Taipei (Taiwan, Province of China). Dept. of Mech. Eng.; Kuo Chengtzu; Chang Rueyming [Institute of Materials Science and Engineering, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30050 (Taiwan, Province of China)

    1997-10-31

    Two different deposition processes were carried out to enhance adherence of diamond films on WC+3-5%Co substrate with Ti-Si as the interlayer. One process can be called two-step diamond deposition process. Another process can be called interlayer heat treatment process. Diamond films were deposited by a microwave plasma chemical vapor deposition system. Ti and Si interlayer are deposited by DC sputter and an E-gun, respectively. Film morphologies, interface structure and film quality were examined by SEM, XRD, Auger electron spectroscopy and Raman spectroscopy. The residual stresses and adhesion strengths of the films were determined by Raman spectroscopy and indentation adhesion testing, respectively. Comparing the regular one-step diamond deposition process with the present two different new processes, the average dP/dX values, which are a measure of the adherence of the film, are 354 kgf/mm, 494 kgf/mm and 787 kgf/mm, respectively. In other words, the interlayer heat treatment process gives the best film adherence on average. For the two-step diamond deposition process, the interlayer thickness and the percent diamond surface coverage of the first diamond deposition step are the main parameters, and there exists an optimum Ti thickness and percent diamond coverage for the best film adherence. The main contribution to better film adherence is not a large difference in residual stress, but is due to the following reasons. The interlayer heat treatment can transform amorphous Si to polycrystalline Si, and may form strong TiC and SiC bonding. The polycrystalline Si and the diamond particles from the first diamond deposition step can be an effective seeds to enhance diamond nucleation. (orig.) 11 refs.

  11. A flexible angle sensor made from MWNT/CuO/Cu{sub 2}O nanocomposite films deposited by an electrophoretic co-deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Toboonsung, Buppachat, E-mail: buppachattt@yahoo.co.th [Physics and General Science Program, Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima 30000 (Thailand); Singjai, Pisith, E-mail: singjai@hotmail.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai, 50200 (Thailand)

    2012-08-25

    Highlights: Black-Right-Pointing-Pointer MWNT/CuO/Cu{sub 2}Onanocomposite films were coated on a PET sheet. Black-Right-Pointing-Pointer The film resistance and application as angle sensor were investigated. Black-Right-Pointing-Pointer Thesensor showed a linear relation between the film resistance and the bending angle. Black-Right-Pointing-Pointer A minimum loop area and a high stability in sensitivity over a thousand bending cycles were obtained. - Abstract: A flexible angle sensor was prepared using an electrophoretic co-deposition process to form nanocomposite networks of multi-wall carbon nanotube/cupric oxide/cuprous oxide (MWNT/CuO/Cu{sub 2}O) on a polyethylene terephthalate (PET) sheet. The deposition method used copper and stainless steel electrodes, and the effects of varying of electrode separation, MWNT concentration in deionized water, voltage and deposition time were studied. The film resistance of the as-deposited samples decreased with increasing the MWNT concentration up to 0.3 mg/ml. The angle sensor showed a linear relation between the film resistance and the bending angle, a relationship that was illustrated with loop area and sensitivity data. The best angle sensor was successfully made with an electrode separation of 8 mm, a concentration of 0.3 mg/ml, a voltage of 10 V and a deposition time of 3 h, parameters that resulted in a minimum loop area and the most stability in sensitivity over a thousand bending cycles.

  12. In situ analysis of thin film deposition processes using time-of-flight (TOF) ion beam analysis methods

    International Nuclear Information System (INIS)

    Im, J.; Lin, Y.; Schultz, J.A.; Auciello, O.H.; Chang, R.P.H.

    1995-05-01

    Non-destructive, in situ methods for characterization of thin film growth phenomena is key to understand thin film growth processes and to develop more reliable deposition procedures, especially for complex layered structures involving multi-phase materials. However, surface characterization methods that use either electrons (e.g. AES or XPS) or low energy ions (SIMS) require an UHV environment and utilize instrumentation which obstructs line of sight access to the substrate and are therefore incompatible with line of sight deposition methods and thin film deposition processes which introduce gas, either part of the deposition or in order to produce the desired phase. We have developed a means of differentially pumping both the ion beam source and detectors of a TOF ion beam surface analysis spectrometer that does not interfere with the deposition process and permits compositional and structural analysis of the growing film in the present system, at pressures up to several mTorr. Higher pressures are feasible with modified source-detector geometry. In order to quantify the sensitivity of Ion Scattering Spectroscopy (ISS) and Direct Recoil Spectroscopy (DRS), we have measured the signal intensity for stabilized clean metals in a variety of gas environments as a function of the ambient gas species and pressure, and ion beam species and kinetic energy. Results are interpreted in terms of collision cross sections which are compared with known gas phase scattering data and provide an apriori basis for the evaluation of time-of-flight ion scattering and recoil spectroscopies (ToF-ISARS) for various industrial processing environments which involve both inert and reactive cases. The cross section data for primary ion-gas molecule and recoiled atom-gas molecule interactions are also provided. from which the maximum operating pressure in any experimental configuration can be obtained

  13. Macro controlling of copper oxide deposition processes and spray mode by using home-made fully computerized spray pyrolysis system

    Science.gov (United States)

    Essa, Mohammed Sh.; Chiad, Bahaa T.; Shafeeq, Omer Sh.

    2017-09-01

    Thin Films of Copper Oxide (CuO) absorption layer have been deposited using home-made Fully Computerized Spray Pyrolysis Deposition system FCSPD on glass substrates, at the nozzle to substrate distance equal to 20,35 cm, and computerized spray mode (continues spray, macro-control spray). The substrate temperature has been kept at 450 °c with the optional user can enter temperature tolerance values ± 5 °C. Also that fixed molar concentration of 0.1 M, and 2D platform speed or deposition platform speed of 4mm/s. more than 1000 instruction program code, and specific design of graphical user interface GUI to fully control the deposition process and real-time monitoring and controlling the deposition temperature at every 200 ms. The changing in the temperature has been recorded during deposition processes, in addition to all deposition parameters. The films have been characterized to evaluate the thermal distribution over the X, Y movable hot plate, the structure and optical energy gap, thermal and temperature distribution exhibited a good and uniform distribution over 20 cm2 hot plate area, X-ray diffraction (XRD) measurement revealed that the films are polycrystalline in nature and can be assigned to monoclinic CuO structure. Optical band gap varies from 1.5-1.66 eV depending on deposition parameter.

  14. Area-selective atomic layer deposition of platinum using photosensitive polyimide.

    Science.gov (United States)

    Vervuurt, René H J; Sharma, Akhil; Jiao, Yuqing; Kessels, Wilhelmus Erwin M M; Bol, Ageeth A

    2016-10-07

    Area-selective atomic layer deposition (AS-ALD) of platinum (Pt) was studied using photosensitive polyimide as a masking layer. The polyimide films were prepared by spin-coating and patterned using photolithography. AS-ALD of Pt using poly(methyl-methacrylate) (PMMA) masking layers was used as a reference. The results show that polyimide has excellent selectivity towards the Pt deposition, after 1000 ALD cycles less than a monolayer of Pt is deposited on the polyimide surface. The polyimide film could easily be removed after ALD using a hydrogen plasma, due to a combination of weakening of the polyimide resist during Pt ALD and the catalytic activity of Pt traces on the polyimide surface. Compared to PMMA for AS-ALD of Pt, polyimide has better temperature stability. This resulted in an improved uniformity of the Pt deposits and superior definition of the Pt patterns. In addition, due to the absence of reflow contamination using polyimide the nucleation phase during Pt ALD is drastically shortened. Pt patterns down to 3.5 μm were created with polyimide, a factor of ten smaller than what is possible using PMMA, at the typical Pt ALD processing temperature of 300 °C. Initial experiments indicate that after further optimization of the polyimide process Pt features down to 100 nm should be possible, which makes AS-ALD of Pt using photosensitive polyimide a promising candidate for patterning at the nanoscale.

  15. Deposition of aerosol particles in bent pipe

    International Nuclear Information System (INIS)

    Matsui, Hiroshi; Ohhata, Tsutomu

    1989-01-01

    An equation to estimate deposition fraction of aerosol particles in a bent pipe is derived and the validity is verified experimentally. The equation is obtained by assuming that the resultant acceleration of the gravity and the centrifugal force induced in the bend acts on the aerosol particles, and is found to give a relatively accurate estimation of the deposition fraction if a certain correction factor is introduced to the equation. The deposition fraction has a minimum against Reynold number, and the deposition due to centrifugal force dominates at greater Reynolds number than that at the minimum deposition fraction. On the other hand, the smaller the radius of curvature of the bend is, the larger the deposition fraction due to the centrifugal force is. (author)

  16. Deposition dynamics of multi-solvent bioinks

    Science.gov (United States)

    Kaneelil, Paul; Pack, Min; Cui, Chunxiao; Han, Li-Hsin; Sun, Ying

    2017-11-01

    Inkjet printing cellular scaffolds using bioinks is gaining popularity due to the advancement of printing technology as well as the growing demands of regenerative medicine. Numerous studies have been conducted on printing scaffolds of biomimetic structures that support the cell production of human tissues. However, the underlying physics of the deposition dynamics of bioinks remains elusive. Of particular interest is the unclear deposition dynamics of multi-solvent bioinks, which is often used to tune the micro-architecture formation. Here we systematically studied the effects of jetting frequency, solvent properties, substrate wettability, and temperature on the three-dimensional deposition patterns of bioinks made of Methacrylated Gelatin and Carboxylated Gelatin. The microflows inside the inkjet-printed picolitre drops were visualized using fluorescence tracer particles to decipher the complex processes of multi-solvent evaporation and solute self-assembly. The evolution of droplet shape was observed using interferometry. With the integrated techniques, the interplay of solvent evaporation, biopolymer deposition, and multi-drop interactions were directly observed for various ink and substrate properties, and printing conditions. Such knowledge enables the design and fabrication of a variety of tissue engineering scaffolds for potential use in regenerative medicine.

  17. Plasma-enhanced chemical vapor deposition for YBCO film fabrication of superconducting fault-current limiter

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Byung Hyuk; Kim, Chan Joong

    2006-05-15

    Since the high-temperature superconductor of oxide type was founded, many researches and efforts have been performed for finding its application field. The YBCO superconducting film fabricated on economic metal substrate with uniform critical current density is considered as superconducting fault-current limiter (SFCL). There are physical and chemical processes to fabricate superconductor film, and it is understood that the chemical methods are more economic to deposit large area. Among them, chemical vapor deposition (CVD) is a promising deposition method in obtaining film uniformity. To solve the problems due to the high deposition temperature of thermal CVD, plasma-enhanced chemical vapor deposition (PECVD) is suggested. This report describes the principle and fabrication trend of SFCL, example of YBCO film deposition by PECVD method, and principle of plasma deposition.

  18. Deposition of Coating to Protect Waste Water Reservoir in Acidic Solution by Arc Thermal Spray Process

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2018-01-01

    Full Text Available The corrosion characteristics of 304 stainless steel (SS and titanium (Ti coatings deposited by the arc thermal spray process in pH 4 solution were assessed. The Ti-sprayed coating exhibits uniform, less porous, and adherent coating morphology compared to the SS-sprayed coating. The electrochemical study, that is, electrochemical impedance spectroscopy (EIS, revealed that as exposure periods to solution were increased, the polarization resistance (Rp decreased and the charge transfer resistance (Rct increased owing to corrosion of the metallic surface and simultaneously at the same time the deposition of oxide films/corrosion on the SS-sprayed surface, while Ti coating transformed unstable oxides into the stable phase. Potentiodynamic studies confirmed that both sprayed coatings exhibited passive tendency attributed due to the deposition of corrosion products on SS samples, whereas the Ti-sprayed sample formed passive oxide films. The Ti coating reduced the corrosion rate by more than six times compared to the SS coating after 312 h of exposure to sulfuric acid- (H2SO4- contaminated water solution, that is, pH 4. Scanning electron microscope (SEM results confirmed the uniform and globular morphology of the passive film on the Ti coating resulting in reduced corrosion. On the other hand, the corrosion products formed on SS-sprayed coating exhibit micropores with a net-like microstructure. X-ray diffraction (XRD revealed the presence of the composite oxide film on Ti-sprayed samples and lepidocrocite (γ-FeOOH on the SS-coated surface. The transformation of TiO and Ti3O into TiO2 (rutile and anatase and Ti3O5 after 312 h of exposure to H2SO4 acid reveals the improved corrosion resistance properties of Ti-sprayed coating.

  19. Interpretation of postdepositional processes related to the formation and destruction of the Jackpile-Paguate uranium deposit, northwest New Mexico

    International Nuclear Information System (INIS)

    Adams, S.S.; Curtis, H.S.; Hafen, P.L.; Salek-Nejad, H.

    1978-01-01

    This paper presents aspects of geological studies conducted on the Jackpile-Paguate uranium deposit in northwestern New Mexico in order to document and interpret certain geological characteristics of the deposit and suggest a sequence of processes which have formed and, in part, destroyed the deposits. The principle contributions of the paper are the field and petrologic observations and the interpretations they permit. 29 refs

  20. Economical Atomic Layer Deposition

    Science.gov (United States)

    Wyman, Richard; Davis, Robert; Linford, Matthew

    2010-10-01

    Atomic Layer Deposition is a self limiting deposition process that can produce films at a user specified height. At BYU we have designed a low cost and automated atomic layer deposition system. We have used the system to deposit silicon dioxide at room temperature using silicon tetrachloride and tetramethyl orthosilicate. Basics of atomic layer deposition, the system set up, automation techniques and our system's characterization are discussed.

  1. World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

    International Nuclear Information System (INIS)

    2009-10-01

    The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

  2. 2D modeling of direct laser metal deposition process using a finite particle method

    Science.gov (United States)

    Anedaf, T.; Abbès, B.; Abbès, F.; Li, Y. M.

    2018-05-01

    Direct laser metal deposition is one of the material additive manufacturing processes used to produce complex metallic parts. A thorough understanding of the underlying physical phenomena is required to obtain a high-quality parts. In this work, a mathematical model is presented to simulate the coaxial laser direct deposition process tacking into account of mass addition, heat transfer, and fluid flow with free surface and melting. The fluid flow in the melt pool together with mass and energy balances are solved using the Computational Fluid Dynamics (CFD) software NOGRID-points, based on the meshless Finite Pointset Method (FPM). The basis of the computations is a point cloud, which represents the continuum fluid domain. Each finite point carries all fluid information (density, velocity, pressure and temperature). The dynamic shape of the molten zone is explicitly described by the point cloud. The proposed model is used to simulate a single layer cladding.

  3. Patterned deposition by atmospheric pressure plasma-enhanced spatial atomic layer deposition

    NARCIS (Netherlands)

    Poodt, P.; Kniknie, B.J.; Branca, A.; Winands, G.J.J.; Roozeboom, F.

    2011-01-01

    An atmospheric pressure plasma enhanced atomic layer deposition reactor has been developed, to deposit Al2O3 films from trimethyl aluminum and an He/O2 plasma. This technique can be used for 2D patterned deposition in a single in-line process by making use of switched localized plasma sources. It

  4. Spatial atomic layer deposition: a route towards further industrialization of atomic layer deposition

    NARCIS (Netherlands)

    Poodt, P.; Cameron, D.C.; Dickey, E.; George, S.M.; Kuznetsov, Vladimir; Parsons, G.N.; Roozeboom, F.; Sundaram, G.; Vermeer, A.

    2012-01-01

    Spatial atomic layer deposition can be used as a high-throughput manufacturing technique in functional thin film deposition for applications such as flexible electronics. This; however, requires low-temperature processing and handling of flexible substrates. The authors investigate the process

  5. Fluid expulsion sites on the Cascadia accretionary prism: mapping diagenetic deposits with processed GLORIA imagery

    Science.gov (United States)

    Carson, Bobb; Seke, Erol; Paskevich, Valerie F.; Holmes, Mark L.

    1994-01-01

    Point-discharge fluid expulsion on accretionary prisms is commonly indicated by diagenetic deposition of calcium carbonate cements and gas hydrates in near-surface (topographic and lithologic information. We have processed GLORIA imagery from the Oregon continental margin to remove topographic effects. A synthetic side scan image was created initially from Sea Beam bathymetric data and then was subtracted iteratively from the original GLORIA data until topographic features disappeared. The residual image contains high-amplitude backscattering that we attribute to diagenetic deposits associated with fluid discharge, based on submersible mapping, Ocean Drilling Program drilling, and collected samples. Diagenetic deposits are concentrated (1) near an out-of-sequence thrust fault on the second ridge landward of the base of the continental slope, (2) along zones characterized by deep-seated strikeslip faults that cut transversely across the margin, and (3) in undeformed Cascadia Basin deposits which overlie incipient thrust faults seaward of the toe of the prism. There is no evidence of diagenetic deposition associated with the frontal thrust that rises from the dècollement. If the dècollement is an important aquifer, apparently the fluids are passed either to the strike-slip faults which intersect the dècollement or to the incipient faults in Cascadia Basin for expulsion. Diagenetic deposits seaward of the prism toe probably consist dominantly of gas hydrates.

  6. Restoration of uranium solution mining deposits

    International Nuclear Information System (INIS)

    Devries, F.W.; Lawes, B.C.

    1982-01-01

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal

  7. Restoration of uranium solution mining deposits

    Energy Technology Data Exchange (ETDEWEB)

    Devries, F.W.; Lawes, B.C.

    1982-01-19

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal.

  8. Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

    International Nuclear Information System (INIS)

    Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

    2014-01-01

    Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

  9. Excimer laser processing of inkjet-printed and sputter-deposited transparent conducting SnO2:Sb for flexible electronics

    International Nuclear Information System (INIS)

    Cranton, Wayne M.; Wilson, Sharron L.; Ranson, Robert; Koutsogeorgis, Demosthenes C.; Chi Kuangnan; Hedgley, Richard; Scott, John; Lipiec, Stephen; Spiller, Andrew; Speakman, Stuart

    2007-01-01

    The feasibility of low-temperature fabrication of transparent electrode elements from thin films of antimony-doped tin oxide (SnO 2 :Sb, ATO) has been investigated via inkjet printing, rf magnetron sputtering and post-deposition excimer laser processing. Laser processing of thin films on both glass and plastic substrates was performed using a Lambda Physik 305i excimer laser, with fluences in the range 20-100 mJ cm -2 reducing sheet resistance from as-deposited values by up to 3 orders of magnitude. This is consistent with TEM analysis of the films that shows a densification of the upper 200 nm of laser-processed regions

  10. Fabrication and characterization of vacuum deposited fluorescein thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jalkanen, Pasi, E-mail: pasi.jalkanen@gmail.co [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kulju, Sampo, E-mail: sampo.j.kulju@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Arutyunov, Konstantin, E-mail: konstantin.arutyunov@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Antila, Liisa, E-mail: liisa.j.antila@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Myllyperkioe, Pasi, E-mail: pasi.myllyperkio@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Ihalainen, Teemu, E-mail: teemu.o.ihalainen@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kaeaeriaeinen, Tommi, E-mail: tommi.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Kaeaeriaeinen, Marja-Leena, E-mail: marja-leena.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Korppi-Tommola, Jouko, E-mail: jouko.korppi-tommola@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland)

    2011-03-31

    Simple vacuum evaporation technique for deposition of dyes on various solid surfaces has been developed. The method is compatible with conventional solvent-free nanofabrication processing enabling fabrication of nanoscale optoelectronic devices. Thin films of fluorescein were deposited on glass, fluorine-tin-oxide (FTO) coated glass with and without atomically layer deposited (ALD) nanocrystalline 20 nm thick anatase TiO{sub 2} coating. Surface topology, absorption and emission spectra of the films depend on their thickness and the material of supporting substrate. On a smooth glass surface the dye initially forms islands before merging into a uniform layer after 5 to 10 monolayers. On FTO covered glass the absorption spectra are similar to fluorescein solution in ethanol. Absorption spectra on ALD-TiO{sub 2} is red shifted compared to the film deposited on bare FTO. The corresponding emission spectra at {lambda} = 458 nm excitation show various thickness and substrate dependent features, while the emission of films deposited on TiO{sub 2} is quenched due to the effective electron transfer to the semiconductor conduction band.

  11. Modeling and simulation of the deposition/relaxation processes of polycrystalline diatomic structures of metallic nitride films

    Science.gov (United States)

    García, M. F.; Restrepo-Parra, E.; Riaño-Rojas, J. C.

    2015-05-01

    This work develops a model that mimics the growth of diatomic, polycrystalline thin films by artificially splitting the growth into deposition and relaxation processes including two stages: (1) a grain-based stochastic method (grains orientation randomly chosen) is considered and by means of the Kinetic Monte Carlo method employing a non-standard version, known as Constant Time Stepping, the deposition is simulated. The adsorption of adatoms is accepted or rejected depending on the neighborhood conditions; furthermore, the desorption process is not included in the simulation and (2) the Monte Carlo method combined with the metropolis algorithm is used to simulate the diffusion. The model was developed by accounting for parameters that determine the morphology of the film, such as the growth temperature, the interacting atomic species, the binding energy and the material crystal structure. The modeled samples exhibited an FCC structure with grain formation with orientations in the family planes of , and . The grain size and film roughness were analyzed. By construction, the grain size decreased, and the roughness increased, as the growth temperature increased. Although, during the growth process of real materials, the deposition and relaxation occurs simultaneously, this method may perhaps be valid to build realistic polycrystalline samples.

  12. Vertically aligned carbon nanotubes black coatings from roll-to-roll deposition process

    Science.gov (United States)

    Goislard de Monsabert, Thomas; Papciak, L.; Sangar, A.; Descarpentries, J.; Vignal, T.; de Longiviere, Xavier; Porterat, D.; Mestre, Q.; Hauf, H.

    2017-09-01

    Vertically aligned carbon nanotubes (VACNTs) have recently attracted growing interest as a very efficient light absorbing material over a broad spectral range making them a superior coating in space optics applications such as radiometry, optical calibration, and stray light elimination. However, VACNT coatings available to-date most often result from batch-to-batch deposition processes thus potentially limiting the manufacturing repeatability, substrate size and cost efficiency of this material.

  13. Single-machine common/slack due window assignment problems with linear decreasing processing times

    Science.gov (United States)

    Zhang, Xingong; Lin, Win-Chin; Wu, Wen-Hsiang; Wu, Chin-Chia

    2017-08-01

    This paper studies linear non-increasing processing times and the common/slack due window assignment problems on a single machine, where the actual processing time of a job is a linear non-increasing function of its starting time. The aim is to minimize the sum of the earliness cost, tardiness cost, due window location and due window size. Some optimality results are discussed for the common/slack due window assignment problems and two O(n log n) time algorithms are presented to solve the two problems. Finally, two examples are provided to illustrate the correctness of the corresponding algorithms.

  14. 25 CFR 42.6 - When does due process require a formal disciplinary hearing?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false When does due process require a formal disciplinary... RIGHTS § 42.6 When does due process require a formal disciplinary hearing? Unless local school policies and procedures provide for less, a formal disciplinary hearing is required before a suspension in...

  15. Half-sandwich cobalt complexes in the metal-organic chemical vapor deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Georgi, Colin [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany); Hapke, Marko; Thiel, Indre [Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT), Albert-Einstein-Straße 29a, Rostock 18059 (Germany); Hildebrandt, Alexander [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany); Waechtler, Thomas; Schulz, Stefan E. [Fraunhofer Institute of Electronic Nano Systems (ENAS), Technologie-Campus 3, Chemnitz 09126 (Germany); Technische Universität Chemnitz, Center for Microtechnologies (ZfM), Chemnitz 09107 (Germany); Lang, Heinrich, E-mail: heinrich.lang@chemie.tu-chemnitz.de [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany)

    2015-03-02

    A series of cobalt half-sandwich complexes of type [Co(η{sup 5}-C{sub 5}H{sub 5})(L)(L′)] (1: L, L′ = 1,5-hexadiene; 2: L = P(OEt){sub 3}, L′ = H{sub 2}C=CHSiMe{sub 3}; 3: L = L′ = P(OEt){sub 3}) has been studied regarding their physical properties such as the vapor pressure, decomposition temperature and applicability within the metal-organic chemical vapor deposition (MOCVD) process, with a focus of the influence of the phosphite ligands. It could be shown that an increasing number of P(OEt){sub 3} ligands increases the vapor pressure and thermal stability of the respective organometallic compound. Complex 3 appeared to be a promising MOCVD precursor with a high vapor pressure and hence was deposited onto Si/SiO{sub 2} (100 nm) substrates. The resulting reflective layer is closed, dense and homogeneous, with a slightly granulated surface morphology. X-ray photoelectron spectroscopy (XPS) studies demonstrated the formation of metallic cobalt, cobalt phosphate, cobalt oxide and cobalt carbide. - Highlights: • Thermal studies and vapor pressure measurements of cobalt half-sandwich complexes was carried out. • Chemical vapor deposition with cobalt half-sandwich complexes is reported. • The use of Co-phosphites results in significant phosphorous-doped metallic layers.

  16. "Ingraham v. Wright" and the Decline of Due Process.

    Science.gov (United States)

    Clark, Gerard J.

    1978-01-01

    Suggests that the constitutional questions in "Ingraham vs Wright" lend credence to a concern that the Court is seeking to eliminate all due process intervention outside of the incorporation and privacy cases and to limit even these cases to defenses of a criminal prosecution. Available from Suffolk University Law Review Office, 41…

  17. Correlations between optical properties, microstructure, and processing conditions of Aluminum nitride thin films fabricated by pulsed laser deposition

    International Nuclear Information System (INIS)

    Baek, Jonghoon; Ma, James; Becker, Michael F.; Keto, John W.; Kovar, Desiderio

    2007-01-01

    Aluminum nitride (AlN) films were deposited using pulsed laser deposition (PLD) onto sapphire (0001) substrates with varying processing conditions (temperature, pressure, and laser fluence). We have studied the dependence of optical properties, structural properties and their correlations for these AlN films. The optical transmission spectra of the produced films were measured, and a numerical procedure was applied to accurately determine the optical constants for films of non-uniform thickness. The microstructure and texture of the films were studied using various X-ray diffraction techniques. The real part of the refractive index was found to not vary significantly with processing parameters, but absorption was found to be strongly dependent on the deposition temperature and the nitrogen pressure in the deposition chamber. We report that low optical absorption, textured polycrystalline AlN films can be produced by PLD on sapphire substrates at both low and high laser fluence using a background nitrogen pressure of 6.0 x 10 -2 Pa (4.5 x 10 -4 Torr) of 99.9% purity

  18. Exogenous deposits

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

  19. Due Process in the Realm of Higher Education: Considerations for Dealing with Students Rights

    Science.gov (United States)

    Fishner, Jason T.

    2006-01-01

    Court decisions have laid out expectations of what due process procedures need to be followed in student disciplinary cases and academic dismissal cases due to poor academic performance. This paper will give show where due process comes from and how it found its way into higher education. It will show that there are differences in the ways public…

  20. Deposition and characteristics of PbS thin films by an in-situ solution chemical reaction process

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Junna; Ji, Huiming; Wang, Jian; Zheng, Xuerong; Lai, Junyun; Liu, Weiyan; Li, Tongfei [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Ma, Yuanliang; Li, Haiqin; Zhao, Suqin [College of Physics and Electronic Information Engineering, Qinghai University for Nationalities, Xining 810007 (China); Jin, Zhengguo, E-mail: zhgjin@tju.edu.cn [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-09-01

    Preferential oriented and uniform PbS thin films were deposited by a room temperature in-situ solution chemical reaction process, in which the lead nitrate as precursor in a form of thin solid films from lead precursor solution was used to react with ammonium sulfide ethanol solution. Influence of 1-butanol addition in the lead precursor solution, Pb:S molar ratios in the separate cationic and anionic solutions, deposition cycle numbers and annealing treatment in Ar atmosphere on structure, morphology, chemical composition and optical absorption properties of the deposited PbS films were investigated based on X-ray diffraction, field emission scanning electron microscopy, energy dispersive spectrometer, atomic force microscopy, selected area electron diffraction, UV–vis, near infrared ray and fourier transform infrared spectroscopy measurements. The results showed that the deposited PbS thin films had a cubic structure and highly preferred orientation along with the plane (100). The deposition rate of single-layer was stable, about 30 nm in thickness per deposition cycle. - Highlights: • Time-efficiency synthetic method for the preparation of lead sulfide (PbS) films • Effect of 1-butanol addition into cationic precursor solution is discussed. • Growth rate of the PbS films is stable at about 30 nm per cycle.

  1. Energy-enhanced atomic layer deposition : offering more processing freedom

    NARCIS (Netherlands)

    Potts, S.E.; Kessels, W.M.M.

    2013-01-01

    Atomic layer deposition (ALD) is a popular deposition technique comprising two or more sequential, self-limiting surface reactions, which make up an ALD cycle. Energy-enhanced ALD is an evolution of traditional thermal ALD methods, whereby energy is supplied to a gas in situ in order to convert a

  2. The deposition of gold nanoparticles in MWCNT forests

    Science.gov (United States)

    de Jong, Franciscus; Buffet, Adeline; Schlueter, Michael

    2015-11-01

    The deposition, i.e. transport and attachment, of small-sized particles is a basic process, on which many applications are based. The innumerable applications range from biology and medicine to engineering. Due to their promising mechanical properties multi-walled carbon nanotubes (MWCNTs) have gained increasing popularity in the past decade. A large number of dense packed vertically aligned MWCNTs form a so-called MWCNT forest. In our study we functionalized the MWCNT forest to filter gold nanoparticles from a colloidal suspension. An experimental investigation was carried out in which the particle deposition kinetics was locally determined with small-angle X-ray scattering (SAXS). Furthermore, inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to verify the local observations. It was concluded that both, SAXS and ICP-AES investigations shows very good agreement. Furthermore, an analytical deposition model was developed based on the DLVO-theory. The experimental and theoretical investigation presented here give insight in the deposition kinetics within a MWCNT forest. The results open up pathways to optimize MWCNT forests for filtering purposes.

  3. Seed defective reduction in automotive Electro-Deposition Coating Process of truck cabin

    Science.gov (United States)

    Sonthilug, Aekkalag; Chutima, Parames

    2018-02-01

    The case study company is one of players in Thailand’s Automotive Industry who manufacturing truck and bus for both domestic and international market. This research focuses on a product quality problem about seed defects occurred in the Electro-Deposition Coating Process of truck cabin. The 5-phase of Six Sigma methodology including D-Define, M-Measure, A-Analyze, I-Improve, and C-Control is applied to this research to identify root causes of problem for setting new parameters of each significant factor. After the improvement, seed defects in this process is reduced from 9,178 defects per unit to 876 defects per unit (90% improvement)

  4. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Yu-Kuang Liao

    2017-04-01

    Full Text Available Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD and chemical bath deposition (CBD as used by the Cu(In,GaSe2 (CIGS thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

  5. Plasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective

    International Nuclear Information System (INIS)

    Anders, Andre

    2007-01-01

    Deposition of films using plasma or plasma-assist can be traced back surprisingly far, namely to the 18th century for arcs and to the 19th century for sputtering. However, only since the 1960s the coatings community considered other processes than evaporation for large scale commercial use. Ion Plating was perhaps the first important process, introducing vapor ionization and substrate bias to generate a beam of ions arriving on the surface of the growing film. Rather independently, cathodic arc deposition was established as an energetic condensation process, first in the former Soviet Union in the 1970s, and in the 1980s in the Western Hemisphere. About a dozen various ion-based coating technologies evolved in the last decades, all characterized by specific plasma or ion generation processes. Gridded and gridless ion sources were taken from space propulsion and applied to thin film deposition. Modeling and simulation have helped to make plasma and ions effects to be reasonably well understood. Yet--due to the complex, often non-linear and non-equilibrium nature of plasma and surface interactions--there is still a place for the experience plasma 'sourcerer'

  6. Thermal plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Heberlein, J.; Pfender, E.

    1993-01-01

    Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

  7. Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

    Directory of Open Access Journals (Sweden)

    Ü. Rannik

    2016-03-01

    Full Text Available A 1-D atmospheric boundary layer (ABL model coupled with a detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution time evolution. The model was applied over a period of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading us to assume well-mixed properties of air, the fluxes at the canopy top frequently deviated from deposition inside the forest. This was due to transformation of aerosol concentration throughout the ABL and resulting complicated pattern of vertical transport. Therefore we argue that the comparison of timescales of aerosol dynamics and deposition defined for the processes below the flux measurement level do not unambiguously describe the importance of aerosol dynamics for vertical transport above the canopy. We conclude that under dynamical conditions reported in the current study the micrometeorological particle flux measurements can significantly deviate from the dry deposition into the canopy. The deviation can be systematic for certain size ranges so that the

  8. Clay minerals in uraniferous deposit of Imouraren (Tim Mersoi basin, Niger): implications on genesis of deposit and on ore treatment process

    International Nuclear Information System (INIS)

    Billon, Sophie

    2014-01-01

    Nigerian uraniferous deposits are located in carboniferous and Jurassic formations of Tim Mersoi basin. AREVA is shareholder of 3 mine sites in this area: SOMAIR and COMINAK, both in exploitation since 1960's and IMOURAREN, 80 km further South, whose exploitation is planned for 2015. Mineralization of Imouraren deposit is included in the fluvial formation of Tchirezrine 2 (Jurassic), composed of channels and flood plains. Facies of channel in-fillings range from coarse sandstones to siltstones, while overflow facies are composed of analcimolites. Secondary mineralogy was acquired during 2 stages: 1- diagenesis, with formation of clay minerals, analcime, secondary quartz and albites, and 2- stage of fluids circulations, which induced alteration of detrital and diagenetic minerals, formation of new phases and uranium deposition. A mineralogical zoning, at the scale of deposit resulted from this alteration. The heterogeneity of Tchirezrine 2, at the level of both facies and mineralogy, is also evidenced during ore treatment, as ore reacts differently depending on its source, with sometimes problems of U recovery. Ore treatment tests showed that analcimes and chlorites were both penalizing minerals, because of 1- the sequestration of U-bearing minerals into analcimes, 2- their dissolution which trends to move away from U solubilization conditions (pH and Eh) and to form numerous sulfates, and 3- problems of percolation. A detection method of analcime-rich ores, based on infrared spectroscopy, was developed in order to optimize ore blending and so to reduce negative effects during ore treatment process. (author)

  9. Responses of Surface Ozone Air Quality to Anthropogenic Nitrogen Deposition

    Science.gov (United States)

    Zhang, L.; Zhao, Y.; Tai, A. P. K.; Chen, Y.; Pan, Y.

    2017-12-01

    Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth's surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface-atmosphere exchange. We combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by addition of atmospheric deposited nitrogen: emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a-1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index (LAI) in the model), could increase surface ozone from increased biogenic VOC emissions, but could also decrease ozone due to higher ozone dry deposition velocities. Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations show general increases over the globe (up to 1.5-2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5-1.0 ppbv decreases over the eastern US, Western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate and land use driven surface ozone changes at regional scales, and partly offset the surface ozone reductions due to land use changes reported in previous studies. Our study emphasizes the complexity of biosphere-atmosphere interactions, which can have important

  10. Catalytic behaviors of ruthenium dioxide films deposited on ferroelectrics substrates, by spin coating process

    International Nuclear Information System (INIS)

    Khachane, M.; Nowakowski, P.; Villain, S.; Gavarri, J.R.; Muller, Ch.; Elaatmani, M.; Outzourhite, A.; Luk'yanchuk, I.; Zegzouti, A.; Daoud, M.

    2007-01-01

    Catalytic ruthenium dioxide films were deposited by spin-coating process on ferroelectric films mainly constituted of SrBi 2 Ta 2 O 9 (SBT) and Ba 2 NaNb 5 O 15 (BNN) phases. After thermal treatment under air, these ferroelectric-catalytic systems were characterized by X-ray diffraction and scanning electron microscopy (SEM). SEM images showed that RuO 2 film morphology depended on substrate nature. A study of CH 4 conversion into CO 2 and H 2 O was carried out using these catalytic-ferroelectric multilayers: the conversion was analyzed from Fourier transform infrared (FTIR) spectroscopy, at various temperatures. Improved catalytic properties were observed for RuO 2 films deposited on BNN oxide layer

  11. Mechanical characteristics of a tool steel layer deposited by using direct energy deposition

    Science.gov (United States)

    Baek, Gyeong Yun; Shin, Gwang Yong; Lee, Eun Mi; Shim, Do Sik; Lee, Ki Yong; Yoon, Hi-Seak; Kim, Myoung Ho

    2017-07-01

    This study focuses on the mechanical characteristics of layered tool steel deposited using direct energy deposition (DED) technology. In the DED technique, a laser beam bonds injected metal powder and a thin layer of substrate via melting. In this study, AISI D2 substrate was hardfaced with AISI H13 and M2 metal powders for mechanical testing. The mechanical and metallurgical characteristics of each specimen were investigated via microstructure observation and hardness, wear, and impact tests. The obtained characteristics were compared with those of heat-treated tool steel. The microstructures of the H13- and M2-deposited specimens show fine cellular-dendrite solidification structures due to melting and subsequent rapid cooling. Moreover, the cellular grains of the deposited M2 layer were smaller than those of the H13 structure. The hardness and wear resistance were most improved in the M2-deposited specimen, yet the H13-deposited specimen had higher fracture toughness than the M2-deposited specimen and heat-treated D2.

  12. Sensor-based atomic layer deposition for rapid process learning and enhanced manufacturability

    Science.gov (United States)

    Lei, Wei

    In the search for sensor based atomic layer deposition (ALD) process to accelerate process learning and enhance manufacturability, we have explored new reactor designs and applied in-situ process sensing to W and HfO 2 ALD processes. A novel wafer scale ALD reactor, which features fast gas switching, good process sensing compatibility and significant similarity to the real manufacturing environment, is constructed. The reactor has a unique movable reactor cap design that allows two possible operation modes: (1) steady-state flow with alternating gas species; or (2) fill-and-pump-out cycling of each gas, accelerating the pump-out by lifting the cap to employ the large chamber volume as ballast. Downstream quadrupole mass spectrometry (QMS) sampling is applied for in-situ process sensing of tungsten ALD process. The QMS reveals essential surface reaction dynamics through real-time signals associated with byproduct generation as well as precursor introduction and depletion for each ALD half cycle, which are then used for process learning and optimization. More subtle interactions such as imperfect surface saturation and reactant dose interaction are also directly observed by QMS, indicating that ALD process is more complicated than the suggested layer-by-layer growth. By integrating in real-time the byproduct QMS signals over each exposure and plotting it against process cycle number, the deposition kinetics on the wafer is directly measured. For continuous ALD runs, the total integrated byproduct QMS signal in each ALD run is also linear to ALD film thickness, and therefore can be used for ALD film thickness metrology. The in-situ process sensing is also applied to HfO2 ALD process that is carried out in a furnace type ALD reactor. Precursor dose end-point control is applied to precisely control the precursor dose in each half cycle. Multiple process sensors, including quartz crystal microbalance (QCM) and QMS are used to provide real time process information. The

  13. A comparison of multi-metal deposition processes utilising gold nanoparticles and an evaluation of their application to 'low yield' surfaces for finger mark development.

    Science.gov (United States)

    Fairley, C; Bleay, S M; Sears, V G; NicDaeid, N

    2012-04-10

    This paper reports a comparison of the effectiveness and practicality of using different multi-metal deposition processes for finger mark development. The work investigates whether modifications can be made to improve the performance of the existing process published by Schnetz. Secondly, we compare the ability of different multi-metal deposition processes to develop finger marks on a range of surfaces with that of other currently used development processes. All published multi-metal deposition processes utilise an initial stage of colloidal gold deposition followed by enhancement of the marks with using a physical developer. All possible combinations of colloidal gold and physical developer stages were tested. The method proposed by Schnetz was shown to be the most effective process, however a modification which reduced the pH of the enhancement solution was revealed to provide the best combination of effectiveness and practicality. In trials comparing the modified formulation with vacuum metal deposition, superglue and powder suspensions on surfaces which typically give low finger mark yields (cling film, plasticised vinyl, leather and masking tape), the modified method produced significantly better results over existing processes for cling film and plasticised vinyl. The modified formulation was found to be ineffective on both masking tape and leather. It is recommended that further tests be carried out on the modified multi-metal deposition formulation to establish whether it could be introduced for operational work on cling film material in particular. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Microbial processes in banded iron formation deposition

    DEFF Research Database (Denmark)

    Posth, Nicole; Konhauser, Kurt; Kappler, Andreas

    2013-01-01

    , remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean......Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

  15. D.C. Arcjet Diamond Deposition

    Science.gov (United States)

    Russell, Derrek Andrew

    1995-01-01

    Polycrystalline diamond films synthesized by a D.C. (direct current) arcjet device was reported for the first time in 1988. This device is capable of higher diamond growth rates than any other form of diamond CVD (chemical vapor deposition) process due to its inherent versatility with regard to the enthalpy and fluid properties of the diamond-depositing vapor. Unfortunately, the versatility of this type of device is contrasted by many difficulties such as arc stability and large heat fluxes which make applying it toward diamond deposition a difficult problem. The purpose of this work was to convert the dc arcjet, which is primarily a metallurgical device, into a commercially viable diamond CVD process. The project was divided into two parts: process development and diagnostics. The process development effort concentrated on the certain engineering challenges. Among these was a novel arcjet design that allowed the carbon-source gas to be injected downstream of the tungsten cathode while still facilitating mixture with the main gas feed. Another engineering accomplishment was the incorporation of a water -cooled substrate cooler/spinner that maintained the substrate at the proper temperature, provided the substrate with a large thermal time constant to reduce thermal shock of the diamond film, and enabled the system to achieve a four -inch diameter growth area. The process diagnostics effort concentrated on measurements aimed at developing a fundamental understanding of the properties of the plasma jet such as temperature, plasma density, Mach number, pressure at the substrate, etc. The plasma temperature was determined to be 5195 K by measuring the rotational temperature of C _2 via optical emission spectroscopy. The Mach number of the plasma jet was determined to be ~6.0 as determined by the ratio of the stagnation pressures before and after the shock wave in the plasma jet. The C_2 concentration in the plasma jet was determined to be {~10 }^{12} cm^ {-3} by

  16. Calculation of financial compensation due of municipalities hosting nuclear waste deposit

    International Nuclear Information System (INIS)

    Silva, Renata A. da; Simoes, Francisco Fernando L.; Martins, Vivian B.

    2011-01-01

    The present work evaluates the math from monthly financial transfers to municipalities with technical viability for building of initial or intermediate repository for storing of radioactivity nuclear waste: gloves, sneakers, mask, resins and filters came from thermonuclear facilities. Several aspects have been considered as the geological factors of the site as presence of capable faults, groundwater vulnerability, infiltration of seawater. Also, it was take into account socioeconomic factors: population density, costs for construction, maintenance and operation of repository; size and activity of waste; among others. Hereafter, we have presented the key features of low and average activity repository and high activity repository even as initial, intermediate and final repository and the possible environment impact. The methodology for calculation of financial compensation of municipalities was established by CNEN will be applied for a specific assumed municipality. The analysis of financial compensation due to the specific nuclear waste deposit and the possible guidelines for the use of that compensation by the municipality will be analyzed. In addiction, it will be compared the model for compensation used for nuclear wastes with other plants receiving permanent wastes from cemeteries and sanitary landfills, where the land should not be allowed for the human activities the same as: crops, livestock and buildings. Also, comparison with royalties and indemnities were paid by facilities of energy production as hydroelectric dams as well as petroleum and gas exploration plants. The destination of financial compensation transfer to the municipality is in charge of the city administration. The compensation could be applied of investments in education and culture, health, sanitation works, improvement of public transport, environment, among others. It will be discussed the cost-benefit relation for the assumed municipality. (author)

  17. Calculation of financial compensation due of municipalities hosting nuclear waste deposit

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Renata A. da, E-mail: renata.amaral@ufrj.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Simoes, Francisco Fernando L.; Martins, Vivian B., E-mail: flamego@ien.gov.b [Instituto de Engenharia Nuclear (LIMA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Impactos Ambientais

    2011-07-01

    The present work evaluates the math from monthly financial transfers to municipalities with technical viability for building of initial or intermediate repository for storing of radioactivity nuclear waste: gloves, sneakers, mask, resins and filters came from thermonuclear facilities. Several aspects have been considered as the geological factors of the site as presence of capable faults, groundwater vulnerability, infiltration of seawater. Also, it was take into account socioeconomic factors: population density, costs for construction, maintenance and operation of repository; size and activity of waste; among others. Hereafter, we have presented the key features of low and average activity repository and high activity repository even as initial, intermediate and final repository and the possible environment impact. The methodology for calculation of financial compensation of municipalities was established by CNEN will be applied for a specific assumed municipality. The analysis of financial compensation due to the specific nuclear waste deposit and the possible guidelines for the use of that compensation by the municipality will be analyzed. In addiction, it will be compared the model for compensation used for nuclear wastes with other plants receiving permanent wastes from cemeteries and sanitary landfills, where the land should not be allowed for the human activities the same as: crops, livestock and buildings. Also, comparison with royalties and indemnities were paid by facilities of energy production as hydroelectric dams as well as petroleum and gas exploration plants. The destination of financial compensation transfer to the municipality is in charge of the city administration. The compensation could be applied of investments in education and culture, health, sanitation works, improvement of public transport, environment, among others. It will be discussed the cost-benefit relation for the assumed municipality. (author)

  18. An adaptation of the Citrosolv process to remove different types of deposits in boilers of a thermo-electric power plant

    International Nuclear Information System (INIS)

    Ferreira, V.C.

    1985-01-01

    During the inspection of a power station boiler was find out a high amount of scale/deposits on the tubes surface (> 100 mg/cm 2 ). The scale/deposits constituents determined in chemical analysis, X-ray fluorescence and X-ray diffraction were iron, copper, calcium, magnesium, phosphorus and silicon. A chemical cleaning based on a small change of Citrosolv process, was used to remove those scale/deposits with sucess. (Author) [pt

  19. Limitations of patterning thin films by shadow mask high vacuum chemical vapor deposition

    International Nuclear Information System (INIS)

    Reinke, Michael; Kuzminykh, Yury; Hoffmann, Patrik

    2014-01-01

    A key factor in engineering integrated devices such as electro-optic switches or waveguides is the patterning of high quality crystalline thin films into specific geometries. In this contribution high vacuum chemical vapor deposition (HV-CVD) was employed to grow titanium dioxide (TiO 2 ) patterns onto silicon. The directed nature of precursor transport – which originates from the high vacuum environment during the process – allows shading certain regions on the substrate by shadow masks and thus depositing patterned thin films. While the use of such masks is an emerging field in stencil or shadow mask lithography, their use for structuring thin films within HV-CVD has not been reported so far. The advantage of the employed technique is the precise control of lateral spacing and of the distance between shading mask and substrate surface which is achieved by manufacturing them directly on the substrate. As precursor transport takes place in the molecular flow regime, the precursor impinging rates (and therefore the film growth rates) on the surface can be simulated as function of the reactor and shading mask geometry using a comparatively simple mathematical model. In the current contribution such a mathematical model, which predicts impinging rates on plain or shadow mask structured substrates, is presented. Its validity is confirmed by TiO 2 -deposition on plain silicon substrates (450 °C) using titanium tetra isopropoxide as precursor. Limitations of the patterning process are investigated by the deposition of TiO 2 on structured substrates and subsequent shadow mask lift-off. The geometry of the deposits is according to the mathematical model. Shading effects due to the growing film enables to fabricate deposits with predetermined variations in topography and non-flat top deposits which are complicated to obtain by classical clean room processes. As a result of the enhanced residual pressure of decomposition products and titanium precursors and the

  20. Gold particle formation via photoenhanced deposition on lithium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Zaniewski, A.M., E-mail: azaniews@asu.edu; Meeks, V.; Nemanich, R.J.

    2017-05-31

    Highlights: • Gold chloride is reduced into solid gold nanoparticles at the surface of a polarized semiconductor. • Reduction processes are driven by ultraviolet light. • Gold nanoparticle and silver nanoparticle deposition patterns are compared. - Abstract: In this work, we report on a technique to reduce gold chloride into sub-micron particles and nanoparticles. We use photoelectron transfer from periodically polarized lithium niobate (PPLN) illuminated with above band gap light to drive the surface reactions required for the reduction and particle formation. The particle sizes and distributions on the PPLN surface are sensitive to the solution concentration, with inhibited nucleation and large particles (>150 nm) for both low (2E−8M to 9E−7M) and high (1E−5M to 1E−3M) concentrations of gold chloride. At midrange values of the concentration, nucleation is more frequent, resulting in smaller sized particles (<150 nm). We compare the deposition process to that for silver, which has been previously studied. We find that the reduction of gold chloride into nanoparticles is inhibited compared to silver ion reduction, due to the multi-step reaction required for gold particle formation. This also has consequences for the resulting deposition patterns: while silver deposits into nanowires along boundaries between areas with opposite signed polarizations, such patterning of the deposition is not observed for gold, for a wide range of concentrations studied (2E−8 to 1E−3M).

  1. Urban wet deposition nitrate: a comparison to non-urban deposition

    International Nuclear Information System (INIS)

    Schultz, J.A.M.

    1994-01-01

    The concentration of nitrate in both wet and dry deposition has both increased historically and currently, and recently parallels emissions in NO x . Since NO x is produced in amounts comparable to SO 2 , it is an important contributor to acid deposition, and is produced in higher amounts in urban areas due to concentrated sources. Prior to to this study, national acid deposition monitoring networks in the United States have been and remain established in non-urban areas. This research study consisted of a comparison of precipitation sampling and analysis of wet deposition nitrate and pH for each deposition event in each of two urban sites over a 15 mo period. Also, a comparison of urban data and data generated at a nearby non-urban NADP site was made by examination of both monthly and seasonal data. This research suggests that national monitoring programs should consider inclusion of urban and non-urban monitoring sites in order to achieve a more representative regional assessment. 24 refs., 2 figs., 2 tabs

  2. Sensitivity of Process Design due to Uncertainties in Property Estimates

    DEFF Research Database (Denmark)

    Hukkerikar, Amol; Jones, Mark Nicholas; Sarup, Bent

    2012-01-01

    The objective of this paper is to present a systematic methodology for performing analysis of sensitivity of process design due to uncertainties in property estimates. The methodology provides the following results: a) list of properties with critical importance on design; b) acceptable levels of...... in chemical processes. Among others vapour pressure accuracy for azeotropic mixtures is critical and needs to be measured or estimated with a ±0.25% accuracy to satisfy acceptable safety levels in design....

  3. The use of a large-strain consolidation model to optimise multilift tailing deposits

    NARCIS (Netherlands)

    Vardon, P.J.; Yao, Y.; Van Paassen, L.A.; Van Tol, A.F.

    2015-01-01

    Thin-lift atmospheric fine drying (AFD) is a technique used to dewater mine and oil sand tailings, which utilises both self-weight consolidation and atmospheric evaporation. The disposed layers undergo a cyclic drying and rewetting process due to precipitation and deposition of additional lifts on

  4. Deposition of aerosols formed by HCDA due to decay heat transport in inner containment atmospheres

    International Nuclear Information System (INIS)

    Vate, J.F. van de

    1976-01-01

    Coupling of decay heat transfer by aerosol-laden inner containment atmospheres with aerosol deposition from such atmospheres leads to useful and simple models for calculation of the time dependence of the aerosol mass concentration. Special attention is given to thermophoretic deposition (dry case) and condensation followed by gravitational deposition (wet case). Attractive features of the models are: 1) coagulation can be omitted and therefore complicated and doubtful calculations on coagulation are avoided, 2) material and particle size of the aerosol are not important for the aerosol decay rate, 3) the aerosol decay rate is related to the decay heat production which is known function of time, and the relevant part of it must be assessed usually for other purposes as well. (orig.) [de

  5. Measured spatial variability of beach erosion due to aeolian processes.

    NARCIS (Netherlands)

    de Vries, S.; Verheijen, A.H.; Hoonhout, B.M.; Vos, S.E.; Cohn, Nicholas; Ruggiero, P; Aagaard, T.; Deigaard, R.; Fuhrman, D.

    2017-01-01

    This paper shows the first results of measured spatial variability of beach erosion due to aeolian processes during the recently conducted SEDEX2 field experiment at Long Beach, Washington, U.S.A.. Beach erosion and sedimentation were derived using series of detailed terrestrial LIDAR measurements

  6. Pulsed Laser Deposition Processing of Improved Titanium Nitride Coatings for Implant Applications

    Science.gov (United States)

    Haywood, Talisha M.

    Recently surface coating technology has attracted considerable attention of researchers to develop novel coatings with enhanced functional properties such as hardness, biocompatibility, wear and corrosion resistance for medical devices and surgical tools. The materials currently being used for surgical implants include predominantly stainless steel (316L), cobalt chromium (Co-Cr), titanium and its alloys. Some of the limitations of these implants include improper mechanical properties, corrosion resistance, cytotoxicity and bonding with bone. One of the ways to improve the performance and biocompatibility of these implants is to coat their surfaces with biocompatible materials. Among the various coating materials, titanium nitride (TiN) shows excellent mechanical properties, corrosion resistance and low cytotoxicity. In the present work, a systematic study of pulsed laser ablation processing of TiN coatings was conducted. TiN thin film coatings were grown on commercially pure titanium (Ti) and stainless steel (316L) substrates at different substrate temperatures and different nitrogen partial pressures using the pulsed laser deposition (PLD) technique. Microstructural, surface, mechanical, chemical, corrosion and biological analysis techniques were applied to characterize the TiN thin film coatings. The PLD processed TiN thin film coatings showed improvements in mechanical strength, corrosion resistance and biocompatibility when compared to the bare substrates. The enhanced performance properties of the TiN thin film coatings were a result of the changing and varying of the deposition parameters.

  7. Influence of Continuous and Discontinuous Depositions on Properties of Ito Films Prepared by DC Magnetron Sputtering

    Science.gov (United States)

    Aiempanakit, K.; Rakkwamsuk, P.; Dumrongrattana, S.

    Indium tin oxide (ITO) films were deposited on glass substrate without external heating by DC magnetron sputtering with continuous deposition of 800 s (S1) and discontinuous depositions of 400 s × 2 times (S2), 200 s × 4 times (S3) and 100 s × 8 times (S4). The structural, surface morphology, optical transmittance and electrical resistivity of ITO films were measured by X-ray diffraction, atomic force microscope, spectrophotometer and four-point probe, respectively. The deposition process of the S1 condition shows the highest target voltage due to more target poisoning occurrence. The substrate temperature of the S1 condition increases with the saturation curve of the RC charging circuit while other conditions increase and decrease due to deposition steps as DC power turns on and off. Target voltage and substrate temperature of ITO films decrease when changing the deposition conditions from S1 to S2, S3 and S4, respectively. The preferential orientation of ITO films were changed from dominate (222) plane to (400) plane with the increasing number of deposition steps. The ITO film for the S4 condition shows the lowest electrical resistivity of 1.44 × 10-3 Ω·cm with the highest energy gap of 4.09 eV and the highest surface roughness of 3.43 nm. These results were discussed from the point of different oxygen occurring on the surface ITO target between the sputtering processes which affected the properties of ITO films.

  8. Low-Temperature Deposition of Layered SnSe2 for Heterojunction Diodes

    KAUST Repository

    Serna, Martha I.

    2018-04-27

    Tin diselenide (SnSe) has been recently investigated as an alternative layered metal dichalcogenide due to its unique electrical and optoelectronics properties. Although there are several reports on the deposition of layered crystalline SnSe films by chemical and physical methods, synthesis methods like pulsed laser deposition (PLD) are not reported. An attractive feature of PLD is that it can be used to grow 2D films over large areas. In this report, a deposition process to grow stoichiometric SnSe on different substrates such as single crystals (Sapphire) and amorphous oxides (SiO and HfO) is reported. A detailed process flow for the growth of 2D SnSe at temperatures of 300 °C is presented, which is substantially lower than temperatures used in chemical vapor deposition and molecular beam epitaxy. The 2D SnSe films exhibit a mobility of ≈4.0 cm V s, and are successfully used to demonstrate SnSe/p-Si heterojunction diodes. The diodes show I /I ratios of 10-10 with a turn on voltage of <0.5 V, and ideality factors of 1.2-1.4, depending on the SnSe film growth conditions.

  9. The role of metasomatism in the balance of halogens in ore-forming process at porphyry Cu-Mo deposits

    Science.gov (United States)

    Berzina, A. N.

    2009-04-01

    Volatile components play an important role in the evolution of ore-magmatic systems and their ore potential. Of special interest are fluorine and chlorine compounds that principally control the transportation of ore elements by the fluid in a magmatic process and under high-temperature hydrothermal conditions. Study of the evolution of fluorine-chlorine activity in the ore-forming process and their source is usually based on analysis of their magmatic history, whereas the additional source of fluorine and chlorine released during metasomatic alteration of rocks hosting mineralization is poorly discussed in the existing literature. Based on microprobe data on Cl and F abundances in halogen-containing minerals (biotite, amphibole, apatite, titanite) in intrusive rocks and their hydrothermally altered varieties, the role of metasomatic processes in the balance of volatiles in the ore-forming system is discussed by the example of porphyry Cu-Mo deposits of Siberia (Russia) and Mongolia. Two groups of the deposits are considered: copper-molybdenum (Erdenetiin Ovoo, Mongolia and Aksug, Russia) with prevailing propylitic and phyllic alteration and molybdenum-copper (Sora, Russia), with predominant potassic alteration. All types of hydrothermal alterations have led to drastic decrease in Cl contents in metasomatic minerals as compared with halogen-containing magmatic minerals. All studied deposits (particularly those where propylitic and phyllic alteration were developed) show a nearly complete chlorine removal from altered halogen-containing rock-forming minerals (biotite and amphibole). The Cl content in amphibole decreases several times at the stage of replacement with actinolite in the process of propylitization. In the later chlorites (ripidolite and brunsvigite) that replace amphibole, actinolite, and biotite, chlorine is not detected by microprobe (detection limit 0.01-0.02% Cl). Chlorine was also not detected in white micas (muscovite-phengite series) in quartz

  10. In vitro characterization of hydroxyapatite layers deposited by APS and HVOF thermal spraying methods

    Directory of Open Access Journals (Sweden)

    Radu Alexandru Roşu

    2012-03-01

    Full Text Available Titanium alloys are successfully used in medicine as implants due to their high mechanical properties and good biocompatibility. To improve implant osseointegration of titanium alloys, they are covered with hydroxyapatite because of its bioactive properties. Coating the implants with hydroxyapatite by thermal spraying, due to the temperatures developed during the deposition process, the structure can be degraded, leading to formation of secondary phases, such as TCP, TT CP, CaO. The paper presents the experimental results of hydroxyapatite layers deposition by two thermal spraying methods: Atmospheric Plasma Spraying (APS and High Velocity Oxy-Fuel (HVOF. The microstructure of the deposited layers is characterized by X-ray diffraction analysis and electronic microscopy. The bioactivity of the hydroxyapatite layers was investigated in Simulated Body Fluid (SBF by immersing the covered samples deposited by the two thermal spraying methods. In both cases the coatings did not present defects as cracks or microcracks. X-ray diffraction performed on hydroxyapatite deposited layers shows that the structure was strongly influenced by plasma jet temperature, the structure consisting mainly of TCP (Ca3PO42. The samples deposited by HVO F after immersing in SBF lead to formation of biological hydroxyapatite, certifying the good bioactivity of the coatings.

  11. On the Deposition Equilibrium of Carbon Nanotubes or Graphite in the Reforming Processes of Lower Hydrocarbon Fuels

    Directory of Open Access Journals (Sweden)

    Zdzisław Jaworski

    2017-11-01

    Full Text Available The modeling of carbon deposition from C-H-O reformates has usually employed thermodynamic data for graphite, but has rarely employed such data for impure filamentous carbon. Therefore, electrochemical data for the literature on the chemical potential of two types of purified carbon nanotubes (CNTs are included in the study. Parameter values determining the thermodynamic equilibrium of the deposition of either graphite or CNTs are computed for dry and wet reformates from natural gas and liquefied petroleum gas. The calculation results are presented as the atomic oxygen-to-carbon ratio (O/C against temperature (200 to 100 °C for various pressures (1 to 30 bar. Areas of O/C for either carbon deposition or deposition-free are computed, and indicate the critical O/C values below which the deposition can occur. Only three types of deposited carbon were found in the studied equilibrium conditions: Graphite, multi-walled CNTs, and single-walled CNTs in bundles. The temperature regions of the appearance of the thermodynamically stable forms of solid carbon are numerically determined as being independent of pressure and the analyzed reactants. The modeling indicates a significant increase in the critical O/C for the deposition of CNTs against that for graphite. The highest rise in the critical O/C, of up to 290% at 30 bar, was found for the wet reforming process.

  12. 252Cf-source-correlated transmission measurements for uranyl fluoride deposit in a 24-in.-OD process pipe

    International Nuclear Information System (INIS)

    Uckan, T.; Mihalczo, J.T.; Valentine, T.E.; Mullens, J.A.

    1998-01-01

    Characterization of a hydrated uranyl fluoride (UO 2 F 2 ·nH 2 O) deposit in a 17-ft-long, 24-in.-OD process pipe at the former Oak Ridge Gaseous Diffusion Plant was successfully performed by using 252 Cf-source-correlated time-of-flight (TOF) transmission measurements. These measurements of neutrons and gamma rays through the pipe from an external 2521 Cf fission source were used to measure the deposit profile and its distribution along the pipe, the hydration (or H/U), and the total uranium mass. The measurements were performed with a source in an ionization chamber on one side of the pipe and detectors on the other. Scanning the pipe vertically and horizontally produced a spatial and time-dependent radiograph of the deposit in which transmitted gamma rays and neutrons were separated in time. The cross-correlation function between the source and the detector was measured with the Nuclear Weapons Identification System. After correcting for pipe effects, the deposit thickness was determined from the transmitted neutrons and H/U from the gamma rays. Results were consistent with a later intrusive observation of the shape and the color of the deposit; i.e., the deposit was annular and was on the top of the pipe at some locations, demonstrating the usefulness of this method for deposit characterization

  13. Behaviour of major, minor and trace elements (including REEs during kaolinization processes at Zonouz deposit, northeast of Marand, East Azarbaidjan province

    Directory of Open Access Journals (Sweden)

    Vahideh Alipour

    2011-11-01

    Full Text Available The Zonouz kaolin deposit is located ~15 km northeast of Marand, East-Azarbaidjan province. Based on physical features in field investigations, such as color, five distinct kaolin types including (1 white, (2 lemon, (3 gray, (4 brown, and (5 yellow are distinguished in the deposit. Field evidence and petrographic studies indicate that the deposit is genetically close to trachy-andesite rocks. According to mineralogical data, the deposit contains quartz, kaolinite, montmorillonite, calcite, pyrophyllite, chlorite, muscovite-illite, dolomite, hematite, and anatase minerals. Geochemical data indicate that function of alteration processes on trachy-andesite rocks during development of Zonouz ore deposit was accompanied by leaching of elements such as Al, Na, K, Rb, Ba, V, Hf, Cu, Zr, Tm, Yb, and Lu, enrichment of elements such as U, Nb, and Ta, and leaching-fixation of elements such as Si, Fe, Ca, Mg, Ti, Mn, P, Cs, Sr, Th, Co, Cr, Ni, Y, Ga, LREE, Tb, Dy, Ho, and Er. Incorporation of obtained results from mineralogical and geochemical studies show that physico-chemical conditions of alteration environment, the relative stability of primary minerals, surface adsorption, preferential sorption by metallic oxides, existing of organic matters, scavenging and concentration processes, and fixation in neomorphic mineralogical phases played important role in distribution of elements in the deposit. Geochemical studies show that development of the deposit is relative to two types of processes, (1 hypogene and (2 supergene. The distribution pattern of REEs indicates that differentiation degree of LREEs from HREEs in supergene kaolins is more than hypogene kaolins. Geochemical studies indicate that minerals such as Mn-oxides, zircon, anatase, hematite, cerianite, and secondary phosphates (monazite, rhabdophane, churchite, and zenotime are the potential hosts for rare earth elements in this deposit.

  14. Deposition and micro electrical discharge machining of CVD-diamond layers incorporated with silicon

    Science.gov (United States)

    Kühn, R.; Berger, T.; Prieske, M.; Börner, R.; Hackert-Oschätzchen, M.; Zeidler, H.; Schubert, A.

    2017-10-01

    In metal forming, lubricants have to be used to prevent corrosion or to reduce friction and tool wear. From an economical and ecological point of view, the aim is to avoid the usage of lubricants. For dry deep drawing of aluminum sheets it is intended to apply locally micro-structured wear-resistant carbon based coatings onto steel tools. One type of these coatings are diamond layers prepared by chemical vapor deposition (CVD). Due to the high strength of diamond, milling processes are unsuitable for micro-structuring of these layers. In contrast to this, micro electrical discharge machining (micro EDM) is a suitable process for micro-structuring CVD-diamond layers. Due to its non-contact nature and its process principle of ablating material by melting and evaporating, it is independent of the hardness, brittleness or toughness of the workpiece material. In this study the deposition and micro electrical discharge machining of silicon incorporated CVD-diamond (Si-CVD-diamond) layers were presented. For this, 10 µm thick layers were deposited on molybdenum plates by a laser-induced plasma CVD process (LaPlas-CVD). For the characterization of the coatings RAMAN- and EDX-analyses were conducted. Experiments in EDM were carried out with a tungsten carbide tool electrode with a diameter of 90 µm to investigate the micro-structuring of Si-CVD-diamond. The impact of voltage, discharge energy and tool polarity on process speed and resulting erosion geometry were analyzed. The results show that micro EDM is a suitable technology for micro-structuring of silicon incorporated CVD-diamond layers.

  15. Microstructural control during direct laser deposition of a β-titanium alloy

    International Nuclear Information System (INIS)

    Qiu, Chunlei; Ravi, G.A.; Attallah, Moataz M.

    2015-01-01

    Graphical abstract: Microstructural development of Ti5553 during Direct Laser Deposition (DLD). - Highlights: • Good structural and geometrical integrity could be achieved by process design. • Build height increases with decreased scanning speed and increased powder flow rate. • Keeping Z increment close to actual layer thickness is crucial for consistent building. • The laser deposited Ti5553 are dominated by mixed columnar and equiaxed grains. • In situ dwelling and annealing promote α precipitation which improves microhardness. - Abstract: A concern associated with Direct Laser Deposition (DLD) is the difficulty in controlling microstructure due to rapid cooling rates after deposition, particularly in beta-Ti alloys. In these alloys, the beta-phase is likely to exist following DLD, instead of the desirable duplex alpha + beta microstructure that gives a good balance of properties. Thus, in this work, a parametric study was performed to assess the role of DLD parameters on porosity, build geometry, and microstructure in a beta-Ti alloy, Ti–5Al–5Mo–5V–3Cr (Ti5553). The builds were examined using optical microscopy, scanning electron microscopy, and X-ray diffraction. Microhardness measurements were performed to assess the degree of re-precipitation of alpha-phase following an in situ dwelling and laser annealing procedure. The study identified several processing conditions that enable deposition of samples with the desired geometry and low porosity level. The microstructure was dominated by beta-phase, except for the region near the substrate where a limited amount of alpha-precipitates was present due to reheating effect. Although the microstructure was a mixture of equiaxed and columnar beta-grains alongside infrequent fine alpha-precipitates, the builds showed fairly uniform microhardness in different regions. In situ dwelling and annealing did not cause an obvious change in porosity, but did promote the formation of alpha-precipitates

  16. Mass-Spectrometric Studies of Catalytic Chemical Vapor Deposition Processes of Organic Silicon Compounds Containing Nitrogen

    Science.gov (United States)

    Morimoto, Takashi; Ansari, S. G.; Yoneyama, Koji; Nakajima, Teppei; Masuda, Atsushi; Matsumura, Hideki; Nakamura, Megumi; Umemoto, Hironobu

    2006-02-01

    The mechanism of catalytic chemical vapor deposition (Cat-CVD) processes for hexamethyldisilazane (HMDS) and trisdimethylaminosilane (TDMAS), which are used as source gases to prepare SiNx or SiCxNy films, was studied using three different mass spectrometric techniques: ionization by Li+ ion attachment, vacuum-ultraviolet radiation and electron impact. The results for HMDS show that Si-N bonds dissociate selectively, although Si-C bonds are weaker, and (CH3)3SiNH should be one of the main precursors of deposited films. This decomposition mechanism did not change when NH3 was introduced, but the decomposition efficiency was slightly increased. Similar results were obtained for TDMAS.

  17. Recent Exploration Progresses on Sandstone-Hosted Uranium Deposits in Northwestern China

    International Nuclear Information System (INIS)

    Li Ziying

    2014-01-01

    Conclusions: 1. China nuclear power development is stimulating exploration for uranium resources. 2. Big progress on exploration for sandstonehosted uranium deposits have been made for recent years. 3. The combined exploration techniques are effectively used for locating ore beds and targeting uranium mineralization. 4. Metallogenic models have played important roles in expansion and new discoveries of u-deposits. 5. Uranium is very mobile and can be enriched in the different types of rocks. 6. Greenish sandstone is due to chlorite alteration by secondary reduction process related to oil and gas and can be used to indicate uranium mineralization.

  18. Epitaxial solution deposition of YBa2Cu3O7-6 coated conductors.

    Energy Technology Data Exchange (ETDEWEB)

    Overmyer, Donald L.; Clem, Paul Gilbert; Siegal, Michael P.; Holesinger, Terry A. (Los Alamos National Laboratory, Los Alamos, NM); Voigt, James A.; Richardson, Jacob J.; Dawley, Jeffrey Todd

    2004-11-01

    A variety of solution deposition routes have been reported for processing complex perovskite-based materials such as ferroelectric oxides and conductive electrode oxides, due to ease of incorporating multiple elements, control of chemical stoichiometry, and feasibility for large area deposition. Here, we report an extension of these methods toward long length, epitaxial film solution deposition routes to enable biaxially oriented YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO)-coated conductors for superconducting transmission wires. Recent results are presented detailing an all-solution deposition approach to YBCO-coated conductors with critical current densities J{sub c} (77 K) > 1 MA/cm{sup 2} on rolling-assisted, biaxially textured, (200)-oriented Ni-W alloy tapes. Solution-deposition methods such as this approach and those of other research groups appear to have promise to compete with vapor phase methods for superconductor electrical properties, with potential advantages for large area deposition and low cost/kA {center_dot} m of wire.

  19. Particle dry deposition to water surfaces: Processes and consequences

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.

    2000-01-01

    flux to coastal waters, atmosphere-surface exchange represents a significant component of the total flux and may be particularly critical during the summertime when both the riverine input and ambient nutrient concentrations are often at a minimum. In this chapter, we present an overview...... of the physical and chemical processes which dictate the quantity (and direction) of atmosphere-surface fluxes of trace chemicals to (and above) water surfaces with particular emphasis on the role of particles. Dry deposition (transfer to the surface in the absence of precipitation) of particles is determined...... efforts to simulate and measure fluxes close to the coastline. These arise in part from the complexity of atmospheric flow in this region where energy and chemical fluxes are highly inhomogeneous in space and time and thermally generated atmospheric circulations are commonplace. (C) 2000 Elsevier Science...

  20. Nucleation and growth of copper phthalocyanine aggregates deposited from solution on planar surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ghani, Fatemeh [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany); Gojzewski, Hubert, E-mail: hubert.gojzewski@put.poznan.pl [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany); Institute of Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan (Poland); Riegler, Hans [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany)

    2015-10-01

    Graphical abstract: - Highlights: • Copper phthalocyanine deposited on planar surfaces by 3 solution process methods. • Aggregate morphology examined for coverage extending over 3 orders of magnitude. • Morphologies vary from small individual domains to mesh-like multilayers. • Nucleation and growth model explains the observed deposit morphologies. - Abstract: Copper phthalocyanine (CuPc) dissolved in trifluoroacetic acid (TFA) is deposited on solid SiO{sub 2} surfaces by solvent evaporation. The deposited CuPc aggregates are investigated by atomic force microscopy (AFM). The CuPc deposits were prepared by spin casting, dip coating, and spray deposition. Depending on the amount of deposited CuPc the aggregate morphology ranges from small individual domains to mesh-like multilayers. Each domain/layer consists of many parallel stacks of CuPc molecules with the square, plate-like molecules piled face-wise within each stack. The parallel stacks are attached sideways (i.e., edgewise attachment molecularly) to the substrate forming “nanoribbons” with uniform thickness of about 1 nm and varying width. The thickness reflects the length of a molecular edge, the width the number of stacks. A nucleation and growth model is presented that explains the observed aggregate and multilayer morphologies as result of the combination of nucleation, transport processes and a consequence of the anisotropic intermolecular interactions due to the shape of the CuPc molecule.

  1. Accessing the Impact of Sea-Salt Emissions on Aerosol Chemical Formation and Deposition Over Pearl River Delta, China

    Science.gov (United States)

    Fan, Q.; Wang, X.; Liu, Y.; Wu, D.; Chan, P. W.; Fan, S.; Feng, Y.

    2015-12-01

    Sea-salt aerosol (SSA) emissions have a significant impact on aerosol pollution and haze formation in the coastal areas. In this study, Models-3/CMAQ modeling system was utilized to access the impact of SSA emissions on aerosol chemical formation and deposition over Pearl River Delta (PRD), China in July 2006. More SSAs were transported inland from the open-ocean under the southeast wind in summertime. Two experiments (with and without SSA emissions in the CMAQ model) were set up to compare the modeling results with each other. The results showed that the increase of sulfate concentrations were more attributable to the primary emissions of coarse SO42- particles in SSA, while the increase of nitrate concentrations were more attributable to secondary chemical formations, known as the mechanisms of chloride depletion in SSA. In the coastal areas, 17.62 % of SO42-, 26.6% of NO3- and 38.2% of PM10 were attributed to SSA emissions, while those portions were less than 1% in the inland areas. The increases of PM10 and its components due to SSA emissions resulted in higher deposition fluxes over PRD, particularly in the coastal areas, except for the wet deposition of nitrate. Nitrate was more sensitive to SSA emissions in chemical formations than sulfate and dry deposition of aerosol was also more sensitive than that for wet deposition. Process analysis of sulfate and nitrate was applied to find out the difference of physical and chemical mechanisms between Guangzhou (the inland areas) and Zhuhai (the coastal areas). The negative contributions of dry deposition process to both sulfate and nitrate concentrations increased if SSA emissions were taken into account in the model, especially for Zhuhai. The negative contributions of cloud process also increased due to cloud scavenging and wet deposition process. In the coastal area, the gas-to-particle conversions became more active with high contributions of aerosol process to nitrate concentrations.

  2. Deposition of particle-bound radionuclides in dry weather, fog, rain and snowfall

    International Nuclear Information System (INIS)

    Oberschachtsiek, D.; Sparmacher, H.; Kreh, R.; Adam, M.; Fuelber, K.; Stegger, J.; Bonka, H.

    1992-01-01

    Radionuclides emitted from nuclear plants and installations are transported in dry weather, because of turbulences and sedimentations, to plant parts above ground and near the ground and to other areas, and deposited there. The deposited activity is proportional to the activity concentration near the deposition area. In the case of particle-bound radionuclides it depends on the aerodynamic particle diameter, surface quality and other factors. In a large number of experiments deposition velocity was measured. In fog the particles to which radionuclides are bound grow by coagulation and condensation. The aerosol size spectrum changes with increasing distance from the place of emission. The type of the fog and the form of the emitted spectrum are important factors which influence this process. With normal activity distributions as a function of the aerodynamic particle diameter, the deposition velocity increases with the distance from the place of emission, up to a final value, due to the shift of the spectrum to larger diameters. (orig.) [de

  3. Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

    DEFF Research Database (Denmark)

    Rannik, Üllar; Zhou, Luxi; Zhou, Putian

    2016-01-01

    of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport...... of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded...... the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading...

  4. Chemical Vapor Deposition of Photocatalyst Nanoparticles on PVDF Membranes for Advanced Oxidation Processes

    Directory of Open Access Journals (Sweden)

    Giovanni De Filpo

    2018-06-01

    Full Text Available The chemical binding of photocatalytic materials, such as TiO2 and ZnO nanoparticles, onto porous polymer membranes requires a series of chemical reactions and long purification processes, which often result in small amounts of trapped nanoparticles with reduced photocatalytic activity. In this work, a chemical vapor deposition technique was investigated in order to allow the nucleation and growth of ZnO and TiO2 nanoparticles onto polyvinylidene difluoride (PVDF porous membranes for application in advanced oxidation processes. The thickness of obtained surface coatings by sputtered nanoparticles was found to depend on process conditions. The photocatalytic efficiency of sputtered membranes was tested against both a model drug and a model organic pollutant in a small continuous flow reactor.

  5. Simulation of a processes of a moving base coating with uniform films by method of physical deposition

    International Nuclear Information System (INIS)

    Avilov, A.A.; Grigorevskij, A.V.; Dudnik, S.F.; Kiryukhin, N.M.; Klyukovich, V.A.; Sagalovich, V.V.

    1989-01-01

    Computational algorithm is developed for calculating thickness of films deposited by physical methods onto a backing of any shape, moving along a given trajectory. The sugegsted algorithm makes it possible to carry out direct simulation on film deposition process and to optimize sources arrangement for obtaining films with a required degree of uniformity. Condensate distribution on a rotating sphere was calculated and here presented. A satisfactory agreement of calculated values with experimental data on metal films obtained by electron-arc spraying, was established

  6. Fundamental aspects of plating technology. 5. The effect of strongly adsorbed species on the morphology of metal deposits

    Energy Technology Data Exchange (ETDEWEB)

    Popov, K I; Rodaljevic, Z P; Krstajic, N V; Novakovic, S D

    1985-07-01

    It is shown that the improvement in the quality of electrodeposits obtained from CdSO/sub 4/ solution in the presence of strongly adsorbed species compared with that of deposits obtained in the absence of such species is due to a decrease in the exchange current density and an increase in the Tafel slope for the deposition process in the former case.

  7. Designing high performance precursors for atomic layer deposition of silicon oxide

    Energy Technology Data Exchange (ETDEWEB)

    Mallikarjunan, Anupama, E-mail: mallika@airproducts.com; Chandra, Haripin; Xiao, Manchao; Lei, Xinjian; Pearlstein, Ronald M.; Bowen, Heather R.; O' Neill, Mark L. [Air Products and Chemicals, Inc., 1969 Palomar Oaks Way, Carlsbad, California 92011 (United States); Derecskei-Kovacs, Agnes [Air Products and Chemicals, Inc., 7201 Hamilton Blvd., Allentown, Pennsylvania 18195 (United States); Han, Bing [Air Products and Chemicals, Inc., 2 Dongsanhuan North Road, Chaoyang District, Beijing 100027 (China)

    2015-01-15

    Conformal and continuous silicon oxide films produced by atomic layer deposition (ALD) are enabling novel processing schemes and integrated device structures. The increasing drive toward lower temperature processing requires new precursors with even higher reactivity. The aminosilane family of precursors has advantages due to their reactive nature and relative ease of use. In this paper, the authors present the experimental results that reveal the uniqueness of the monoaminosilane structure [(R{sub 2}N)SiH{sub 3}] in providing ultralow temperature silicon oxide depositions. Disubstituted aminosilanes with primary amines such as in bis(t-butylamino)silane and with secondary amines such as in bis(diethylamino)silane were compared with a representative monoaminosilane: di-sec-butylaminosilane (DSBAS). DSBAS showed the highest growth per cycle in both thermal and plasma enhanced ALD. These findings show the importance of the arrangement of the precursor's organic groups in an ALD silicon oxide process.

  8. Reduced thermal budget processing of Y--Ba--Cu--O high temperature superconducting thin films by metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Singh, R.; Sinha, S.; Hsu, N.J.; Ng, J.T.C.; Chou, P.; Thakur, R.P.S.; Narayan, J.

    1991-01-01

    Metalorganic chemical vapor deposition (MOCVD) has the potential of emerging as a viable technique to fabricate ribbons, tapes, coated wires, and the deposition of films of high temperature superconductors, and related materials. As a reduced thermal budget processing technique, rapid isothermal processing (RIP) based on incoherent radiation as the source of energy can be usefully coupled to conventional MOCVD. In this paper we report on the deposition and characterization of high quality superconducting thin films of Y--Ba--Cu--O (YBCO) on MgO and SrTiO 3 substrates by RIP assisted MOCVD. By using a mixture of N 2 O and O 2 as the oxygen source films deposited initially at 600 degree C for 1 min and then at 740 degree C for 30 min are primarily c-axis oriented and with zero resistance being observed at 84 and 89 K for MgO and SrTiO 3 substrates, respectively. The zero magnetic field current densities at 77 K for MgO and SrTiO 3 substrates are 1.2x10 6 and 1.5x10 6 A/cm 2 , respectively. It is envisaged that high energy photons from the incoherent light source and the use of a mixture of N 2 O and O 2 as the oxygen source, assist chemical reactions and lower overall thermal budget for processing of these films

  9. The Influence of the Coating Deposition Process on the Interdiffusion Behavior Between Nickel-Based Superalloys and MCrAlY Bond Coats

    Science.gov (United States)

    Elsaß, M.; Frommherz, M.; Oechsner, M.

    2018-02-01

    In this work, interdiffusion between two nickel-based superalloys and two MCrAlY bond coats is investigated. The MCrAlY bond coats were applied using two different spraying processes, high velocity oxygen fuel spraying (HVOF) and low-pressure plasma spraying. Of primary interest is the evolution of Kirkendall porosity, which can form at the interface between substrate and bond coat and depends largely on the chemical compositions of the coating and substrate. Experimental evidence further suggested that the formation of Kirkendall porosity depends on the coating deposition process. Formation of porosity at the interface causes a degradation of the bonding strength between substrate and coating. After coating deposition, the samples were annealed at 1050 °C for up to 2000 h. Microstructural and compositional analyses were performed to determine and evaluate the Kirkendall porosity. The results reveal a strong influence of both the coating deposition process and the chemical compositions. The amount of Kirkendall porosity formed, as well as the location of appearance, is largely influenced by the coating deposition process. In general, samples with bond coats applied by means of HVOF show accelerated element diffusion. It is hypothesized that recrystallization of the substrate material is a main root cause for these observations.

  10. Processes in Environmental Depositional Systems and Deformation in Sedimentary Basins: Goals for Exoloration in Mexico

    Science.gov (United States)

    Sandoval-Ochoa, J.

    2005-05-01

    Among the recent needs to establish new goals in the mexican energy industry to increase the petroleum reserves, has been necessary to recapitulate on some academic an operative concepts and definitions applied to the Petroliferous Basins Exploration; first of all, in order to understand the Petroleum System in given tectonophysical framework. The tectonophysical environment experienced by the petroliferous basin in the southwestern Gulf of Mexico, merely in the Campeche Sound and adjacent terrestrial regions (Figure 1); has been the result of interaction among the tectonic plates, the Coco's Plate with impingement and subduction beneath the Northamerican Plate and the Yucatán Microplate and even in very deep connection with the oceanic crust of southwesternmost portion of the Gulf of Mexico and the one of the Caribbean sea beneath the gulf of Belize-Honduras. The tectonosedimentary effects in the Campeche Bay starting with the skeleton formed for the Cenozoic Era, kept simultaneous conditions in depositions and deformations because of strain, stress and collapse fields, acted through this Era up to the present day, as observed in the surface Aguayo et al, 1999 and Sandoval, 2000. The involved portions of the crust and its boundaries have also been performing the relative sinking of the mere southwestern centre of the Gulf of Mexico, and the rising of the southeastern lands of Mexico. In the middle contiguity are found the productive Tertiary basins of: Comalcalco, Macuspana, Salina del Itsmo, Campeche-Champoton and other in deep waters; all of them, in an arrangement of basins among distensive faulted blocks in echelon, falling down to the deep centre of the Gulf Sandoval, op cit. With this scenario and that ones of other basins, a recapitulation on concepts and definitions, has been made on the regional natural processes of the environmental depositional systems and on the basins analysis in the tectonophysical framework, in order to reflect on the

  11. Effect of deposition strategy on the microstructure and mechanical properties of Inconel 625 superalloy fabricated by pulsed plasma arc deposition

    International Nuclear Information System (INIS)

    Xu, F.J.; Lv, Y.H.; Xu, B.S.; Liu, Y.X.; Shu, F.Y.; He, P.

    2013-01-01

    Highlights: ► PPAD Inconel 625 sample deposited with ICS strategy exhibits improved surface quality. ► ICS sample exhibits finer microstructure and improved mechanical properties. ► Higher level γ′ and γ″ phases are precipitated in the ICS sample. ► STA heat treatment reduced the concentration of Nb element. ► STA heat treatment improved the mechanical properties of PPAD Inconel 625. -- Abstract: Pulsed plasma arc deposition (PPAD), which combines pulsed plasma cladding with rapid prototyping, is a promising technology for manufacturing near net shape components due to its superiority in cost and convenience of processing. The aim of this study was to investigate the influences of interpass cooling strategy (ICS) and continuous deposition strategy (CDS) on microstructure and mechanical properties of the PPAD Inconel 625 non-ferrous alloy. The as-deposited samples in the two conditions were subjected to the post heat treatment: 980 °C solution treatment + direct aging (STA). The microstructures and mechanical properties of the samples were characterized by means of scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), micro-hardness and tensile testers. It was found that the as-deposited microstructure exhibited homogenous cellular dendrite structure, which grew epitaxially along the deposition direction. The as-deposited microstructure of ICS sample revealed smaller dendritic arm spacing, less niobium segregation and discontinuous finer Laves phase in the interdendritic regions compared to the case of continuous deposition strategy (CDS). The ICS sample exhibited better mechanical properties than CDS sample. After STA heat treatment, a large amount of Laves particles in the interdendritic regions were dissolved, resulting in the reduction of Nb segregation and the precipitation of needle-like δ (Ni 3 Nb). The tensile and yield strength of the as-deposited samples were

  12. Ionized physical vapor deposition (IPVD): A review of technology and applications

    International Nuclear Information System (INIS)

    Helmersson, Ulf; Lattemann, Martina; Bohlmark, Johan; Ehiasarian, Arutiun P.; Gudmundsson, Jon Tomas

    2006-01-01

    In plasma-based deposition processing, the importance of low-energy ion bombardment during thin film growth can hardly be exaggerated. Ion bombardment is an important physical tool available to materials scientists in the design of new materials and new structures. Glow discharges and in particular, the magnetron sputtering discharge have the advantage that the ions of the discharge are abundantly available to the deposition process. However, the ion chemistry is usually dominated by the ions of the inert sputtering gas while ions of the sputtered material are rare. Over the last few years, various ionized sputtering techniques have appeared that can achieve a high degree of ionization of the sputtered atoms, often up to 50% but in some cases as much as approximately 90%. This opens a complete new perspective in the engineering and design of new thin film materials. The development and application of magnetron sputtering systems for ionized physical vapor deposition (IPVD) is reviewed. The application of a secondary discharge, inductively coupled plasma magnetron sputtering (ICP-MS) and microwave amplified magnetron sputtering, is discussed as well as the high power impulse magnetron sputtering (HIPIMS), the self-sustained sputtering (SSS) magnetron, and the hollow cathode magnetron (HCM) sputtering discharges. Furthermore, filtered arc-deposition is discussed due to its importance as an IPVD technique. Examples of the importance of the IPVD-techniques for growth of thin films with improved adhesion, improved microstructures, improved coverage of complex shaped substrates, and increased reactivity with higher deposition rate in reactive processes are reviewed

  13. 19 CFR 210.28 - Depositions.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Depositions. 210.28 Section 210.28 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.28 Depositions. (a) When depositions may be...

  14. Basic Substantive Law for Paralegals: Contracts, Torts, and Due Process.

    Science.gov (United States)

    Marcin, Raymond B.

    Part of the paralegal, or legal assistant, training materials prepared by the National Paralegal Institution under a Federal grant, the text comprises an overview of the basic legal concepts usually found in introductory law courses concerning contracts, torts, and the due process area of constitutional law. Part 1, Contracts, covers: definition,…

  15. Wet and dry deposition and resuspension of AFCT/TFCT fuel processing radionuclides. Final report

    International Nuclear Information System (INIS)

    Slinn, W.G.N.; Katen, P.C.; Wolf, M.A.; Loveland, W.D.; Radke, L.F.; Miller, E.L.; Ghannam, L.J.; Reynolds, B.W.; Vickers, D.

    1979-09-01

    After short summary and introductory chapters, Chapter IV contains a critical analysis of available parameterizations for resuspension and for wet and dry removal processes and recommends interim parameterizations for use in radiation dose calculations. Chapter V describes methods and experimental results from field studies of in-cloud vs below-cloud scavenging, precipitation efficiency, and modifications of aerosols by clouds. In Chapter VI are contained descriptions of methods and results from four different approaches to the problem of measuring the dry deposition velocities of submicron aerosol particles depositing on vegetation. Chapter VII describes experimental results from a study of resuspension and weathering of tracer aerosol particles deposited on soil, grass and gravel; typical resuspension rates were found to be of the order of 10 -8 s -1 and it is recommended that the concept of weathering be reassessed. In Chapter VIII, National Weather Service data are used to obtain Lagrangian statistics for use in a regional-scale study of wet and dry removal. Chapter IX develops new concepts in reservoir models for application at regional to global scales. In the final chapter are some comments about the results found in this study and recommendations for future research

  16. Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

    International Nuclear Information System (INIS)

    Cho, Young Joon; Shin, Woong-Chul; Chang, Hyo Sik

    2014-01-01

    Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al 2 O 3 , we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al 2 O 3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al 2 O 3 film. • Ozone-based Al 2 O 3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

  17. Interpretation of sedimentological processes of coarse-grained deposits applying a novel combined cluster and discriminant analysis

    Directory of Open Access Journals (Sweden)

    Farics Éva

    2017-10-01

    Full Text Available The main aim of this paper is to determine the depositional environments of an Upper-Eocene coarse-grained clastic succession in the Buda Hills, Hungary. First of all, we measured some commonly used parameters of samples (size, amount, roundness and sphericity in a much more objective overall and faster way than with traditional measurement approaches, using the newly developed Rock Analyst application. For the multivariate data obtained, we applied Combined Cluster and Discriminant Analysis (CCDA in order to determine homogeneous groups of the sampling locations based on the quantitative composition of the conglomerate as well as the shape parameters (roundness and sphericity. The result is the spatial pattern of these groups, which assists with the interpretation of the depositional processes. According to our concept, those sampling sites which belong to the same homogeneous groups were likely formed under similar geological circumstances and by similar geological processes.

  18. Modern sedimentary facies, depositional environments, and major controlling processes on an arid siliciclastic coast, Al qahmah, SE Red Sea, Saudi Arabia

    Science.gov (United States)

    Nabhan, Abdullah I.; Yang, Wan

    2018-04-01

    The facies and environments along the arid siliciclastic coast of Red Sea in Al Qahmah, Saudi Arabia are studied to establish a depositional model for interpretation of ancient rocks deposited in rift settings. Field and petrographic studies of 151 sediment samples in an area of 20 km2 define seven main facies types: beach, washover fan, tidal channel, dune, sabkha, delta, and wadi (seasonal stream). The wadi and delta facies are composed of poorly to moderately well-sorted, gravelly, medium-to-fine sands. Delta-front sands are redistributed by southward longshore currents to form a beach. Beach facies is composed of well-to-moderately sorted fine sands with minor gravels, which contain high concentrations of magnetite, ilmenite, garnet, pyroxene, amphibole, epidote, titanite, and apatite grains, indicating strong winnowing. Crabs and other burrowers destroy primary sedimentary structures and mix sediments in foreshore and backshore of the beaches. Wind and storm surge rework foreshore and backshore sediments to form washover fans. Sabkha facies occurs extensively in supratidal depressions behind beach, are flooded by rainstorms and spring tide, and capped by a 5-cm-thick crust composed of interlaminated halite, quartz, albite, minor gypsum and biotite, and rarely calcium carbonate. Halite occurs as thin sheets and gypsum as nodules with a chicken-wire structure. Clastic fraction in sabkha sediments ranges from coarse silt to coarse sand with moderate sorting, and is transported by currents and wind. Tidal inlets and tidal creeks assume abandoned wadis and are filled by muddy sand. Sand dunes and sand sheets are 1-7 m high and widely distributed due to variable wind directions. Fine-grained dune sands are moderately well sorted, whereas sheet sands are coarser and poorly sorted due to vegetation baffling. Most eolian sands are sourced from beach deposits. This suite of complex riverine, wave, tidal, wind, chemical, and biological processes form the facies mosaic

  19. Transport and solubility of Hetero-disperse dry deposition particulate matter subject to urban source area rainfall-runoff processes

    Science.gov (United States)

    Ying, G.; Sansalone, J.

    2010-03-01

    SummaryWith respect to hydrologic processes, the impervious pavement interface significantly alters relationships between rainfall and runoff. Commensurate with alteration of hydrologic processes the pavement also facilitates transport and solubility of dry deposition particulate matter (PM) in runoff. This study examines dry depositional flux rates, granulometric modification by runoff transport, as well as generation of total dissolved solids (TDS), alkalinity and conductivity in source area runoff resulting from PM solubility. PM is collected from a paved source area transportation corridor (I-10) in Baton Rouge, Louisiana encompassing 17 dry deposition and 8 runoff events. The mass-based granulometric particle size distribution (PSD) is measured and modeled through a cumulative gamma function, while PM surface area distributions across the PSD follow a log-normal distribution. Dry deposition flux rates are modeled as separate first-order exponential functions of previous dry hours (PDH) for PM and suspended, settleable and sediment fractions. When trans-located from dry deposition into runoff, PSDs are modified, with a d50m decreasing from 331 to 14 μm after transport and 60 min of settling. Solubility experiments as a function of pH, contact time and particle size using source area rainfall generate constitutive models to reproduce pH, alkalinity, TDS and alkalinity for historical events. Equilibrium pH, alkalinity and TDS are strongly influenced by particle size and contact times. The constitutive leaching models are combined with measured PSDs from a series of rainfall-runoff events to demonstrate that the model results replicate alkalinity and TDS in runoff from the subject watershed. Results illustrate the granulometry of dry deposition PM, modification of PSDs along the drainage pathway, and the role of PM solubility for generation of TDS, alkalinity and conductivity in urban source area rainfall-runoff.

  20. Multilayer Porous Crucibles for the High Throughput Salt Separation from Uranium Deposits

    International Nuclear Information System (INIS)

    Kwon, S. W.; Park, K. M.; Kim, J. G.; Kim, I. T.; Seo, B. K.; Moon, J. G.

    2013-01-01

    Solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. A physical separation process, such as a distillation separation, is more attractive than a chemical or dissolution process because physical processes generate much less secondary process. Distillation process was employed for the cathode processsing due to the advantages of minimal generation of secondary waste, compact unit process, simple and low cost equipment. The basis for vacuum distillation separation is the difference in vapor pressures between salt and uranium. A solid cathode deposit is heated in a heating region and salt vaporizes, while nonvolatile uranium remains behind. It is very important to increase the throughput of the salt separation system owing to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. The evaporation rate of the LiCl-KCl eutectic salt in vacuum distiller is not so high to come up with the generation capacity of uranium dendrites in an electro-refiner. Therefore, a wide evaporation area or high distillation temperature is necessary for the successful salt separation. In this study, it was attempted to enlarge a throughput of the salt distiller with a multilayer porous crucibles for the separation of adhered salt in the uranium deposits generated from the electrorefiner. The feasibility of the porous crucibles was tested by the salt distillation experiments. In this study, the salt distiller with multilayer porous crucibles was proposed and the feasibility of liquid salt separation was examined to increase a throughput. It was found that the effective separation of salt from uranium deposits was possible by the multilayer porous crucibles

  1. Multilayer Porous Crucibles for the High Throughput Salt Separation from Uranium Deposits

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. W.; Park, K. M.; Kim, J. G.; Kim, I. T.; Seo, B. K.; Moon, J. G. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. A physical separation process, such as a distillation separation, is more attractive than a chemical or dissolution process because physical processes generate much less secondary process. Distillation process was employed for the cathode processsing due to the advantages of minimal generation of secondary waste, compact unit process, simple and low cost equipment. The basis for vacuum distillation separation is the difference in vapor pressures between salt and uranium. A solid cathode deposit is heated in a heating region and salt vaporizes, while nonvolatile uranium remains behind. It is very important to increase the throughput of the salt separation system owing to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. The evaporation rate of the LiCl-KCl eutectic salt in vacuum distiller is not so high to come up with the generation capacity of uranium dendrites in an electro-refiner. Therefore, a wide evaporation area or high distillation temperature is necessary for the successful salt separation. In this study, it was attempted to enlarge a throughput of the salt distiller with a multilayer porous crucibles for the separation of adhered salt in the uranium deposits generated from the electrorefiner. The feasibility of the porous crucibles was tested by the salt distillation experiments. In this study, the salt distiller with multilayer porous crucibles was proposed and the feasibility of liquid salt separation was examined to increase a throughput. It was found that the effective separation of salt from uranium deposits was possible by the multilayer porous crucibles.

  2. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.N. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-12-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated critical to the life and economy of the advanced fossil energy systems as the higher temperatures and corrosive environments exceed the limits of known structural materials to accommodate the service conditions. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. A new development is the demonstration of advanced aluminide-based ESD coatings for erosion and wear applications. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that yields an order of magnitude increase in deposition rates and achievable coating thicknesses. Achieving this regime has required the development of advanced ESD electronic capabilities. Development is now focused on further improvements in deposition rates, system reliability when operating at process extremes, and economic competitiveness.

  3. Dry Deposition from Sahara Sources Regions of Western Africa

    Directory of Open Access Journals (Sweden)

    B. Douaiba

    2014-01-01

    Full Text Available Sahara dust storms during March 2004 have attracted much attention from the dust-research community due to their intensity, wide coverage, and endurance. In the present work, the dry deposition mechanisms of mineral dust are analysed during an event on the 3 March 2004 over the Northwest African coast. This particular case was chosen based on the strong dry removal that occurred, rendering it ideal for examining the deposition processes. The simulation of synoptic conditions and dry deposition of four dust particles including clay, small silt, large silt, and sand was performed with Eta model, coupled with a desert dust cycle module. The results have been compared with surface data from weather stations in North Africa, data of dry metals from stations located in Gran Canaria, and various satellite images such as European Organization for the Exploitation of Meteorological Satellites and Moderate Resolution Imaging Spectroradiometer for the period in question.

  4. Boron erosion and carbon deposition due to simultaneous bombardment with deuterium and carbon ions in plasmas

    International Nuclear Information System (INIS)

    Ohya, K.; Kawata, J.; Wienhold, P.; Karduck, P.; Rubel, M.; Seggern, J. von

    1999-01-01

    Erosion of boron out of a thin film exposed to deuterium edge plasmas and the simultaneous carbon deposition have been investigated in the tokamak TEXTOR-94 and simulated by means of a dynamic Monte Carlo code. The calculated results are compared with some observations (colorimetry, spectroscopy and AES) during and after the exposures. The implantation of carbon impurities strongly changes the effective boron sputtering yield of the film, which results into a lowering of the film erosion and a formation of thick carbon deposits. A strong decrease in the observed BII line emission around a surface location far from the plasma edge can be explained by a carbon deposition on the film. The calculated carbon depth profiles in the film, depending on the distance of the exposed surface from the plasma edge, are in reasonable agreement with measurements by AES after the exposures. Although simultaneous surface erosion and carbon deposition can be simulated, the calculated erosion rate is larger, by a factor of 2, than the observations by colorimetry at the early stage of the exposure

  5. Effects of deposited pyrolytic carbon on some mechanical properties of zircaloy-4 tubes. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    Shrkawy, S W; Abdel-razek, I D; El-Sayed, H A [Metallurgy Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Zircaloy cladding tubes are not compatible with the uranium fuel pellets as they suffer from failure due to pelletclad interaction (PCI). A carbon coating, as used in the canadian CANLUB fuel elements, is thought to improve the cladding performance with respect to the PCI problem. In this paper pyrolytic carbon coating was deposited on zircaloy-4 cladding tubes by the thermal cracking of commercial butant gas at the temperature range 250-450 degree C. In order to evaluate the effect of gaseous species on the mechanical properties of the tubes tensile and microhardness testing measurements were performed on samples prepared from the coated tubes. The fractured surface of the tensile zircaloy tubes and the deposited carbon coating, both, were examined by the SEM. The results of the tensile tests of zircaloy-4 tubes indicated that the coating process has insignificant effect on the ultimate strength of the tubes tested. The values of Vickers hardness numbers were not significantly changed across the tubes thickness. The microstructure of deposited carbon, due to the cracking process, was granular in all the temperature range (250-450 degree C) studied. 9 figs., 1 tab.

  6. The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

    Directory of Open Access Journals (Sweden)

    Rachel M. Thorman

    2015-09-01

    Full Text Available Focused electron beam induced deposition (FEBID is a single-step, direct-write nanofabrication technique capable of writing three-dimensional metal-containing nanoscale structures on surfaces using electron-induced reactions of organometallic precursors. Currently FEBID is, however, limited in resolution due to deposition outside the area of the primary electron beam and in metal purity due to incomplete precursor decomposition. Both limitations are likely in part caused by reactions of precursor molecules with low-energy (3, Pt(PF34, Co(CO3NO, and W(CO6. Through these case studies, it is evident that this combination of studies can provide valuable insight into potential mechanisms governing deposit formation in FEBID. Although further experiments and new approaches are needed, these studies are an important stepping-stone toward better understanding the fundamental physics behind the deposition process and establishing design criteria for optimized FEBID precursors.

  7. Studies on ion scattering and sputtering processes relevant to ion beam sputter deposition of multicomponent thin films

    International Nuclear Information System (INIS)

    Auciello, O.; Ameen, M.S.; Kingon, A.I.

    1989-01-01

    Results from computer simulation and experiments on ion scattering and sputtering processes in ion beam sputter deposition of high Tc superconducting and ferroelectric thin films are presented. It is demonstrated that scattering of neutralized ions from the targets can result in undesirable erosion of, and inert gas incorporation in, the growing films, depending on the ion/target atom ass ratio and ion beam angle of incidence/target/substrate geometry. The studies indicate that sputtering Kr + or Xe + ions is preferable to the most commonly used Ar + ions, since the undesirable phenomena mentioned above are minimized for the first two ions. These results are used to determine optimum sputter deposition geometry and ion beam parameters for growing multicomponent oxide thin films by ion beam sputter-deposition. 10 refs., 5 figs

  8. Prototyping of radially oriented piezoelectric ceramic-polymer tube composites using fused deposition and lost mold processing techniques

    Science.gov (United States)

    McNulty, Thomas Francis

    Piezoelectric tube composite hydrophones of 3-1, 3-2, and 2-2 connectivity were developed using Fused Deposition (FD) and lost mold processing (LMP). In this work, a new series of thermoplastic binder formulations, named the ECG series, were developed for the FD process. The ECG-9 formulation exhibits mechanical, thermal, and rheological properties suitable for the Fused Deposition of functional lead zirconate titanate ceramic devices. This binder consists of 100 parts (by weight) Vestoplast 408, 20 parts Escorez 2520, 15 parts Vestowax A-227, and 5 parts Indopol H-1500. Oleic acid, oleyl alcohol, stearic acid, and stearyl alcohol (in toluene) were tested for use as a dispersant in the PZT/ECG-9 system. It was found that stearic acid adsorbs the most onto PZT powder, adsorbing 8.1 mg/m2. Using stearic acid, solutions of increasing concentration (5.0--50.0 g/l) were measured for adsorption. It was found that 30.0 g/l is the minimum concentration necessary for optimum surface coverage. The surfactant-coated powder was compounded with ECG-9 binder to create a 54 vol.% mix. The mix was extruded using a single screw extrusion apparatus into continuous lengths (>30 m) of 1.78 mm diameter filament. Fused Deposition was used to create composite designs of 3-1, 3-2, and 2-2 connectivity. After sintering, samples exhibit a sintered density greater than 97%. Sanders Prototyping (SPI) was used to manufacture molds for use with LMP techniques. Molds of 3-1, 3-2, and 2-2 connectivity were developed. The molds were infiltrated with a 55 vol.% aqueous based PZT slurry. The parts were subjected to a binder decomposition cycle, followed by sintering. Resultant samples were highly variable due to random macro-pores present in the samples after sintering. The resultant preforms were embedded in epoxy, and polished to dimensions of 8.0 mm inside diameter (ID), 14.0 mm outside diameter (OD), and 10.0 mm length (l) the OD and l dimensions are accurate to +/--2%, while the ID is accurate

  9. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  10. Extension of the lifetime of tantalum filaments in the hot-wire (Cat) 3 Chemical Vapor Deposition process

    CSIR Research Space (South Africa)

    Knoesen, D

    2008-01-01

    Full Text Available , the filament is again exposed to pure hydrogen for a minimum of 5 min, the chamber then again evacuated to a vacuum better than 8×10−8 mbar before cutting the power to the filament. This has resulted in a filament life of 11 months, with an accumulated... process only treated by annealing before a deposition run, did not last long, and typically broke after 3 to 5 h of accumulated deposition time. Silicide formation is found along the full length of these tantalum filaments, with severe structural...

  11. Compact Layers of Hybrid Halide Perovskites Fabricated via the Aerosol Deposition Process-Uncoupling Material Synthesis and Layer Formation.

    Science.gov (United States)

    Panzer, Fabian; Hanft, Dominik; Gujar, Tanaji P; Kahle, Frank-Julian; Thelakkat, Mukundan; Köhler, Anna; Moos, Ralf

    2016-04-08

    We present the successful fabrication of CH₃NH₃PbI₃ perovskite layers by the aerosol deposition method (ADM). The layers show high structural purity and compactness, thus making them suitable for application in perovskite-based optoelectronic devices. By using the aerosol deposition method we are able to decouple material synthesis from layer processing. Our results therefore allow for enhanced and easy control over the fabrication of perovskite-based devices, further paving the way for their commercialization.

  12. Spectro-Morphologic Analysis of Pyroclastic Deposits on Mercury

    Science.gov (United States)

    Doressoundiram, A.; Besse, S.; Hersérant, W.

    2014-12-01

    Observations of the MESSENGER spacecraft in orbit around Mercury have shown that volcanism is a very important process that has shaped the surface of the planet. Kerber et al. [2011,2014] have identified 200 pyroclastic deposits candidates based on color ratio and morphology images. Goudge et al. [2014] used the visible portion of the MASCS spectrometer to do further analysis on the spectral nature of the deposits. The authors have shown that the deposits have specific UV properties probably caused by Oxygen-Metal charges transfer, and a correlation between the slope of the UV-downturn and the age of the surrounding terrains. In this study, we use the full range of the MASCS spectrometer (300-1400nm) to characterize the spectral properties of the pyroclastic deposits. Moreover, additional observations have been obtained since the last publications, and this allows specific studies of previously non-imaged deposits. This study shows that the visible slope of the deposits is changing as a function of distance from the vent, as seen on the Moon for pyroclastic deposits and their mafic absorption bands [Besse et al, 2013]. This is consistent with a decrease of thickness of the deposits that are mixed with background material. Surprisingly, the UV-downturn parameter proposed by Goudge et al. [2014] does not change as the distance to the vent increase. Eventually, the near infrared portion does not appear to have absorption bands in the range 900nm-1200nm, consistent with the very low iron abundance of the surface of Mercury. This could also be due to the lower signal to noise ratio of the near infrared portion of the MASCS instrument, and further analysis are needed to confirm these results. The use of visible images from the MDIS camera has revealed that some of the pyroclastic deposits candidates are certainly correlated with hollows.

  13. Processing-Microstructure-Property Relationships for Cold Spray Powder Deposition of Al-Cu Alloys

    Science.gov (United States)

    2015-06-01

    Champagne [18]. The simulations were completed to compare the simulated particle exit velocities versus the measured particle exit velocities. In...620 m/s to 670 m/s [39]. V. Champagne states that for pure aluminum, an acceptable critical velocity for the deposition of pure aluminum is anything...Materials and Processess, vol. 168, no. 5, pp. 53–55, May 2010. [3] V. K. Champagne and P. F. Leyman, “Cold Spray Process Development for the Reclamation

  14. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    International Nuclear Information System (INIS)

    Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R.M.

    2015-01-01

    Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence

  15. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Bloisi, Francesco, E-mail: bloisi@na.infn.it [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy); Calabria, Raffaela; Califano, Valeria [Istituto Motori – CNR, Naples (Italy); Depero, Laura E. [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Federici, Stefania [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Massoli, Patrizio [Istituto Motori – CNR, Naples (Italy); Vicari, Luciano R.M. [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy)

    2015-05-01

    Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

  16. Photoluminescence properties of poly (p-phenylene vinylene) films deposited by chemical vapor deposition

    International Nuclear Information System (INIS)

    Gedelian, Cynthia A.; Rajanna, K.C.; Premerlani, Brian; Lu, Toh-Ming

    2014-01-01

    Photoluminescence spectra of PPV at varying thicknesses and temperatures have been studied. A study of the quenching of the polymer film using a modified version of fluorescence spectroscopy reveals interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. The application of the Stern–Volmer equation to solid film is discussed. Stern–Volmer plots were nonlinear with downward deviations at higher thickness of the film which was explained due to self-quenching in films and larger conformational change and increased restriction from change in electron density due to electron transition during excitation in bulk polymer films over 60 nm thick. PPV deposited into porous (∼4 nm in diameter) nanostructured substrate shows a larger 0–0 than 0–1 transition peak intensity and decreased disorder in the films due to structure imposed by substrate matrix. Temperature dependent effects are measured for a film at 500 Å, right on the border between the two areas. PPV films deposited on porous methyl silsesquioxane (MSQ) were also examined in order to compare the flat film to a substrate that allows for the domination of interface effects. The enthalpies of the first two peaks are very similar, but the third peak demonstrates a lower enthalpy and a larger wavelength shift with temperature. Films deposited inside pores show a smaller amount of disorder than flat films. Calculation of the Huang–Rhys factor at varying temperatures for the flat film and film in porous MSQ shows large temperature dependence for the flat film but a smaller amount of disorder in the nanostructured film. -- Highlights: • Poly (p-phenylene vinylene) films deposited by chemical vapor deposition exhibited photoluminescence properties. • Fluorescence spectra of the polymer films revealed interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. • Stern–Volmer plots were

  17. Synthesis of few-layer, large area hexagonal-boron nitride by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Glavin, Nicholas R. [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States); School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States); Jespersen, Michael L. [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States); University of Dayton Research Institute, 300 College Park, Dayton, OH 45469 (United States); Check, Michael H. [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States); Hu, Jianjun [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States); University of Dayton Research Institute, 300 College Park, Dayton, OH 45469 (United States); Hilton, Al M. [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States); Wyle Laboratories, Dayton, OH 45433 (United States); Fisher, Timothy S. [School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States); Voevodin, Andrey A. [Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH 45433 (United States)

    2014-12-01

    Pulsed laser deposition (PLD) has been investigated as a technique for synthesis of ultra-thin, few-layer hexagonal boron nitride (h-BN) thin films on crystalline highly ordered pyrolytic graphite (HOPG) and sapphire (0001) substrates. The plasma-based processing technique allows for increased excitations of deposited atoms due to background nitrogen gas collisional ionizations and extended resonance time of the energetic species presence at the condensation surface. These processes permit growth of thin, polycrystalline h-BN at 700 °C, a much lower temperature than that required by traditional growth methods. Analysis of the as-deposited films reveals epitaxial-like growth on the nearly lattice matched HOPG substrate, resulting in a polycrystalline h-BN film, and amorphous BN (a-BN) on the sapphire substrates, both with thicknesses of 1.5–2 nm. Stoichiometric films with boron-to-nitrogen ratios of unity were achieved by adjusting the background pressure within the deposition chamber and distance between the target and substrate. The reduction in deposition temperature and formation of stoichiometric, large-area h-BN films by PLD provide a process that is easily scaled-up for two-dimensional dielectric material synthesis and also present a possibility to produce very thin and uniform a-BN. - Highlights: • PLD was used to synthesize boron nitride thin films on HOPG and sapphire substrates. • Lattice matched substrate allowed for formation of polycrystalline h-BN. • Nitrogen gas pressure directly controlled film chemistry and structure. • Technique allows for ultrathin, uniform films at reduced processing temperatures.

  18. Directed Vapor Deposition: Low Vacuum Materials Processing Technology

    National Research Council Canada - National Science Library

    Groves, J. F; Mattausch, G; Morgner, H; Hass, D. D; Wadley, H. N

    2000-01-01

    Directed vapor deposition (DVD) is a recently developed electron beam-based evaporation technology designed to enhance the creation of high performance thick and thin film coatings on small area surfaces...

  19. Acidic deposition: State of science and technology. Report 10. Watershed and lake processes affecting surface-water acid-base chemistry. Final report

    International Nuclear Information System (INIS)

    Turner, R.S.; Cook, R.B.; Miegroet, H.V.; Johnson, D.W.; Elwood, J.W.

    1990-09-01

    The acid-base chemistry of surface waters is governed by the amount and chemistry of deposition and by the biogeochemical reactions that generate acidity or acid neutralizing capacity (ANC) along the hydrologic pathways that water follows through watersheds to streams and lakes. The amount of precipitation and it chemical loading depend on the area's climate and physiography, on it proximity to natural or industrial gaseous or particulate sources, and on local or regional air movements. Vegetation interacts with the atmosphere to enhance both wet and dry deposition of chemicals to a greater or lesser extent, depending on vegetation type. Vegetation naturally acidifies the environment in humid regions through processes of excess base cation uptake and generation of organic acids associated with many biological processes. Natural acid production and atmospheric deposition of acidic materials drive the acidification process. The lake or stream NAC represents a balance between the acidity-and ANC-generating processes that occur along different flow paths in the watershed and the relative importance of each flow path

  20. Nitrogen deposition to the United States: distribution, sources, and processes

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-05-01

    Full Text Available We simulate nitrogen deposition over the US in 2006–2008 by using the GEOS-Chem global chemical transport model at 1/2°×2/3° horizontal resolution over North America and adjacent oceans. US emissions of NOx and NH3 in the model are 6.7 and 2.9 Tg N a−1 respectively, including a 20% natural contribution for each. Ammonia emissions are a factor of 3 lower in winter than summer, providing a good match to US network observations of NHx (≡NH3 gas + ammonium aerosol and ammonium wet deposition fluxes. Model comparisons to observed deposition fluxes and surface air concentrations of oxidized nitrogen species (NOy show overall good agreement but excessive wintertime HNO3 production over the US Midwest and Northeast. This suggests a model overestimate N2O5 hydrolysis in aerosols, and a possible factor is inhibition by aerosol nitrate. Model results indicate a total nitrogen deposition flux of 6.5 Tg N a−1 over the contiguous US, including 4.2 as NOy and 2.3 as NHx. Domestic anthropogenic, foreign anthropogenic, and natural sources contribute respectively 78%, 6%, and 16% of total nitrogen deposition over the contiguous US in the model. The domestic anthropogenic contribution generally exceeds 70% in the east and in populated areas of the west, and is typically 50–70% in remote areas of the west. Total nitrogen deposition in the model exceeds 10 kg N ha−1 a−1 over 35% of the contiguous US.

  1. Electrochemically Deposited Polypyrrole for Dye-Sensitized Solar Cell Counter Electrodes

    Directory of Open Access Journals (Sweden)

    Khamsone Keothongkham

    2012-01-01

    Full Text Available Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current or direct current process. They were then used as the dye-sensitized solar cell counter electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle-like structure on the conductive glass. The amount of deposited polypyrrole (or film thickness increased with the deposition duration, and the performance of polypyrrole based-dye-sensitized solar cells is dependant upon polymer thickness. The highest efficiency of alternative current and direct current polypyrrole based-dye-sensitized solar cells (DSSCs is 4.72% and 4.02%, respectively. Electrochemical impedance spectroscopy suggests that the superior performance of alternative current polypyrrole solar cells is due to their lower charge-transfer resistance between counter electrode and electrolyte. The large charge-transfer resistance of direct current solar cells is attributed to the formation of unbounded polypyrrole chains minimizing the I3 − reduction rate.

  2. Net atmospheric mercury deposition to Svalbard: Estimates from lacustrine sediments

    Science.gov (United States)

    Drevnick, Paul E.; Yang, Handong; Lamborg, Carl H.; Rose, Neil L.

    2012-11-01

    In this study we used lake sediments, which faithfully record Hg inputs, to derive estimates of net atmospheric Hg deposition to Svalbard, Norwegian Arctic. With the exception of one site affected by local pollution, the study lakes show twofold to fivefold increases in sedimentary Hg accumulation since 1850, likely due to long-range atmospheric transport and deposition of anthropogenic Hg. Sedimentary Hg accumulation in these lakes is a linear function of the ratio of catchment area to lake area, and we used this relationship to model net atmospheric Hg flux: preindustrial and modern estimates are 2.5 ± 3.3 μg m-2 y-1 and 7.0 ± 3.0 μg m-2 y-1, respectively. The modern estimate, by comparison with data for Hg wet deposition, indicates that atmospheric mercury depletion events (AMDEs) or other dry deposition processes contribute approximately half (range 0-70%) of the net flux. Hg from AMDEs may be moving in significant quantities into aquatic ecosystems, where it is a concern because of contamination of aquatic food webs.

  3. Seasonal atmospheric deposition and air-sea gaseous exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes

    Science.gov (United States)

    Jiang, Y.; Guo, Z.

    2017-12-01

    As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of air samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of air-sea gaseous exchange and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous exchange of PAHs was referred as the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH exchange flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and air-sea concentration gradient difference among seasons. Based on the simplified mass balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at air

  4. Electrospark deposition for die repair

    Directory of Open Access Journals (Sweden)

    J. Tušek

    2012-01-01

    Full Text Available The electrospark deposition is a process for surfacing of hard metal alloys, e.g. carbides and stellites, on the surfaces of new or old machine elements. In this process, a high current is conducted through an oscillating electrode and a substrate for a very short period of time. In the paper, the process is described and the thickness of deposited layer, chemical composition, dilution rate and the layer roughness are determined.

  5. Robofurnace: A semi-automated laboratory chemical vapor deposition system for high-throughput nanomaterial synthesis and process discovery

    International Nuclear Information System (INIS)

    Oliver, C. Ryan; Westrick, William; Koehler, Jeremy; Brieland-Shoultz, Anna; Anagnostopoulos-Politis, Ilias; Cruz-Gonzalez, Tizoc; Hart, A. John

    2013-01-01

    Laboratory research and development on new materials, such as nanostructured thin films, often utilizes manual equipment such as tube furnaces due to its relatively low cost and ease of setup. However, these systems can be prone to inconsistent outcomes due to variations in standard operating procedures and limitations in performance such as heating and cooling rates restrict the parameter space that can be explored. Perhaps more importantly, maximization of research throughput and the successful and efficient translation of materials processing knowledge to production-scale systems, relies on the attainment of consistent outcomes. In response to this need, we present a semi-automated lab-scale chemical vapor deposition (CVD) furnace system, called “Robofurnace.” Robofurnace is an automated CVD system built around a standard tube furnace, which automates sample insertion and removal and uses motion of the furnace to achieve rapid heating and cooling. The system has a 10-sample magazine and motorized transfer arm, which isolates the samples from the lab atmosphere and enables highly repeatable placement of the sample within the tube. The system is designed to enable continuous operation of the CVD reactor, with asynchronous loading/unloading of samples. To demonstrate its performance, Robofurnace is used to develop a rapid CVD recipe for carbon nanotube (CNT) forest growth, achieving a 10-fold improvement in CNT forest mass density compared to a benchmark recipe using a manual tube furnace. In the long run, multiple systems like Robofurnace may be linked to share data among laboratories by methods such as Twitter. Our hope is Robofurnace and like automation will enable machine learning to optimize and discover relationships in complex material synthesis processes

  6. Robofurnace: A semi-automated laboratory chemical vapor deposition system for high-throughput nanomaterial synthesis and process discovery

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, C. Ryan; Westrick, William; Koehler, Jeremy; Brieland-Shoultz, Anna; Anagnostopoulos-Politis, Ilias; Cruz-Gonzalez, Tizoc [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Hart, A. John, E-mail: ajhart@mit.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2013-11-15

    Laboratory research and development on new materials, such as nanostructured thin films, often utilizes manual equipment such as tube furnaces due to its relatively low cost and ease of setup. However, these systems can be prone to inconsistent outcomes due to variations in standard operating procedures and limitations in performance such as heating and cooling rates restrict the parameter space that can be explored. Perhaps more importantly, maximization of research throughput and the successful and efficient translation of materials processing knowledge to production-scale systems, relies on the attainment of consistent outcomes. In response to this need, we present a semi-automated lab-scale chemical vapor deposition (CVD) furnace system, called “Robofurnace.” Robofurnace is an automated CVD system built around a standard tube furnace, which automates sample insertion and removal and uses motion of the furnace to achieve rapid heating and cooling. The system has a 10-sample magazine and motorized transfer arm, which isolates the samples from the lab atmosphere and enables highly repeatable placement of the sample within the tube. The system is designed to enable continuous operation of the CVD reactor, with asynchronous loading/unloading of samples. To demonstrate its performance, Robofurnace is used to develop a rapid CVD recipe for carbon nanotube (CNT) forest growth, achieving a 10-fold improvement in CNT forest mass density compared to a benchmark recipe using a manual tube furnace. In the long run, multiple systems like Robofurnace may be linked to share data among laboratories by methods such as Twitter. Our hope is Robofurnace and like automation will enable machine learning to optimize and discover relationships in complex material synthesis processes.

  7. Seasonal atmospheric deposition and air-sea gas exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implications for source-sink processes

    Science.gov (United States)

    Jiang, Yuqing; Lin, Tian; Wu, Zilan; Li, Yuanyuan; Li, Zhongxia; Guo, Zhigang; Yao, Xiaohong

    2018-04-01

    In this work, air samples and surface seawater samples covering four seasons from March 2014 to January 2015 were collected from a background receptor site in the YRE to explore the seasonal fluxes of air-sea gas exchange and dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. Gaseous PAH release from seawater to the atmosphere averaged 3114 ± 1999 ng m-2 d-1 in a year round. The air-sea gas exchange of PAHs was the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of total dry and wet deposition. The gas PAH exchange flux was dominated by three-ring PAHs, with the highest value in summer and lowest in winter, indicating a marked seasonal variation owing to differences in Henry's law constants associated with temperature, as well as wind speed and gaseous-dissolved gradient among seasons. Based on the simplified mass balance estimation, a net 11 tons y-1 of PAHs (mainly three-ring PAHs) were volatilized from seawater to the atmosphere in a ∼20,000 km2 area in the YRE. Other than the year-round Yangtze River input and ocean ship emissions, the selective release of low-molecular-weight PAHs from bottom sediments in winter due to resuspension triggered by the East Asian winter monsoon is another potential source of PAHs. This work suggests that the source-sink processes of PAHs at the air-sea interface in the YRE play a crucial role in regional cycling of PAHs.

  8. Fog deposition fluxes of water and ions to a mountainous site in Central Europe

    Science.gov (United States)

    Klemm, Otto; Wrzesinsky, Thomas

    2007-09-01

    Fog and precipitation composition and deposition were measured over a 1-yr period. Ion concentrations were higher in fog than in precipitation by factors of between 6 and 18. The causes of these differences were less dilution of fog water due to non-availability of condensable water vapour, and more efficient transfer of surface emissions to fog water as compared to rain water or snow. Fogwater and dissolved ions depositions were measured with eddy covariance in combination with a bulk fogwater collector. Annual fogwater deposition was 9.4% that of precipitation. The annual deposition of ions through fog was of the same order as that for precipitation. Ammonium, representing local emission sources, had 46% more annual deposition through fog than through precipitation. The fog droplet number and mass size distributions are reported. Fog droplets of 15 μm diameter contribute most to the deposition flux. The variability of processes and parameters contributing to deposition of ions through fog (ion concentrations in fog water, liquid water content in air, fog duration and turbulence) is high.

  9. OES control of a low-pressure DC arc at TiN layer deposition

    International Nuclear Information System (INIS)

    Andreev, M.A.; Maksimenko, V.N.; Ershov-Pavlov, E.A.

    1995-01-01

    Results are presented of a low-pressure DC arc study as applied for a deposition of TiN wear-resistant coatings in a commercial plant. Plasma parameters of the arc have been measured by optical emission spectroscopy. The plasma emission spectra have been recorded using a grating spectrometer equipped with an on line computer. Changes in the resulting layers due to a difference in working conditions have been determined by metallography and X-ray analysis giving composition, microstructure and thickness of the resulting layers. Using the data, a correlation between emission spectra of the arc and the TiN layer characteristics has been found. The results allow monitoring parameters of the deposition process to obtain necessary quality of the layer and to increase the process efficiency

  10. Phosphorus atomic layer doping in SiGe using reduced pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    Yamamoto, Yuji; Heinemann, Bernd; Murota, Junichi; Tillack, Bernd

    2014-01-01

    Phosphorus (P) atomic layer doping in SiGe is investigated at temperatures between 100 °C to 600 °C using a single wafer reduced pressure chemical vapor deposition system. SiGe(100) surface is exposed to PH 3 at different PH 3 partial pressures by interrupting SiGe growth. The impact of the SiGe buffer/cap growth condition (total pressure/SiGe deposition precursors) on P adsorption, incorporation, and segregation are investigated. In the case of SiH 4 -GeH 4 -H 2 gas system, steeper P spikes due to lower segregation are observed by SiGe cap deposition at atmospheric (ATM) pressure compared with reduced pressure (RP). The steepness of P spike of ∼ 5.7 nm/dec is obtained for ATM pressure without reducing deposition temperature. This result may be due to the shift of equilibrium of P adsorption/desorption to desorption direction by higher H 2 pressure. Using Si 2 H 6 -GeH 4 -H 2 gas system for SiGe cap deposition in RP, lowering the SiGe growth temperature is possible, resulting in higher P incorporation and steeper P profile due to reduced desorption and segregation. In the case of Si 2 H 6 -GeH 4 -H 2 gas system, the P dose could be simulated assuming a Langmuir-type kinetics model. Incorporated P shows high electrical activity, indicating P is adsorbed mostly in lattice position. - Highlights: • Phosphorus (P) atomic layer doping in SiGe (100) is investigated using CVD. • P adsorption is suppressed by the hydrogen termination of Ge surface. • By SiGe cap deposition at atmospheric pressure, P segregation was suppressed. • By using Si 2 H 6 -based SiGe cap, P segregation was also suppressed. • The P adsorption process is self-limited and follows Langmuir-type kinetics model

  11. High-energy high-rate pulsed-power processing of materials by powder consolidation and by railgun deposition. Technical report (Final), 10 April 1985-10 February 1987

    Energy Technology Data Exchange (ETDEWEB)

    Persad, C.; Marcus, H.L.; Weldon, W.F.

    1987-03-31

    This exploratory research program was initiated to investigate the potential of using pulse power sources for powder consolidation, deposition and other high-energy high-rate processing. The characteristics of the high-energy-high-rate (1MJ/s) powder consolidation using megampere current pulses from a homopolar generator, were defined. Molybdenum Alloy TZM, a nickel-based metallic glass, copper/graphite composites, and P/M aluminum alloy X7091 were investigated. The powder-consolidation process produced high densification rates. Density values of 80% to 99% could be obtained with subsecond high-temperature exposure. Specific energy input and applied pressure were controlling process parameters. Time temperature transformation (TTT) concepts underpin a fundamental understanding of pulsed power processing. Inherent control of energy input, and time-to-peak processing temperature developed to be held to short times. Deposition experiments were conducted using an exploding-foil device (EFD) providing an armature feed to railgun mounted in a vacuum chamber. The material to be deposited - in plasma, gas, liquid, or solid state - was accelerated electromagnetically in the railgun and deposited on a substrate. Deposits of a wide variety of single- and multi-specie materials were produced on several types of substrates. In a series of ancillary experiments, pulsed-skin-effect heating and self quenching of metallic conductors was discovered to be a new means of surface modification by high-energy high-rate-processing.

  12. Effect of process parameters on formability of laser melting deposited 12CrNi2 alloy steel

    Science.gov (United States)

    Peng, Qian; Dong, Shiyun; Kang, Xueliang; Yan, Shixing; Men, Ping

    2018-03-01

    As a new rapid prototyping technology, the laser melting deposition technology not only has the advantages of fast forming, high efficiency, but also free control in the design and production chain. Therefore, it has drawn extensive attention from community.With the continuous improvement of steel performance requirements, high performance low-carbon alloy steel is gradually integrated into high-tech fields such as aerospace, high-speed train and armored equipment.However, it is necessary to further explore and optimize the difficult process of laser melting deposited alloy steel parts to achieve the performance and shape control.This article took the orthogonal experiment on alloy steel powder by laser melting deposition ,and revealed the influence rule of the laser power, scanning speed, powder gas flow on the quality of the sample than the dilution rate, surface morphology and microstructure analysis were carried out.Finally, under the optimum technological parameters, the Excellent surface quality of the alloy steel forming part with high density, no pore and cracks was obtained.

  13. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  14. Process qualification and testing of LENS deposited AY1E0125 D-bottle brackets

    International Nuclear Information System (INIS)

    Atwood, Clinton J.; Smugeresky, John E.; Jew, Michael; Gill, David Dennis; Scheffel, Simon

    2006-01-01

    The LENS Qualification team had the goal of performing a process qualification for the Laser Engineered Net Shaping(trademark)(LENS(reg s ign)) process. Process Qualification requires that a part be selected for process demonstration. The AY1E0125 D-Bottle Bracket from the W80-3 was selected for this work. The repeatability of the LENS process was baselined to determine process parameters. Six D-Bottle brackets were deposited using LENS, machined to final dimensions, and tested in comparison to conventionally processed brackets. The tests, taken from ES1E0003, included a mass analysis and structural dynamic testing including free-free and assembly-level modal tests, and Haversine shock tests. The LENS brackets performed with very similar characteristics to the conventionally processed brackets. Based on the results of the testing, it was concluded that the performance of the brackets made them eligible for parallel path testing in subsystem level tests. The testing results and process rigor qualified the LENS process as detailed in EER200638525A

  15. Characterization on the electrophoretic deposition of the 8 mol% yttria-stabilized zirconia nanocrystallites prepared by a sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Kuo, C.-W. [Department of Resources Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Shih, C.-J. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan (China); Hung, I-M. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Fung, K.-Z. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wen, S.-B. [Department of Resources Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, M.-C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan (China)]. E-mail: cjshih@kmu.edu.tw

    2007-02-15

    An 8 mol% yttria-stabilized zirconia (8YSZ) films are electrophoretically deposited on the La{sub 0.8}Sr{sub 0.2}MnO{sub 3} substrate using 8YSZ nanocrystallites prepared by a sol-gel process. Effects of liquid suspension on the particle zeta potential and degree of agglomeration at different pH values are investigated. When the pH value deviates from the point of zero charge (PZC), the adsorption of protons on particle surfaces cause higher zeta potential and well-dispersed suspension. The optimal values of the iodine concentration, applied voltage and deposition time for the electrophoretic deposition of 8YSZ films are also found.

  16. Characterisation of silicon carbide films deposited by plasma-enhanced chemical vapour deposition

    International Nuclear Information System (INIS)

    Iliescu, Ciprian; Chen Bangtao; Wei Jiashen; Pang, A.J.

    2008-01-01

    The paper presents a characterisation of amorphous silicon carbide films deposited in plasma-enhanced chemical vapour deposition (PECVD) reactors for MEMS applications. The main parameter was optimised in order to achieve a low stress and high deposition rate. We noticed that the high frequency mode (13.56 MHz) gives a low stress value which can be tuned from tensile to compressive by selecting the correct power. The low frequency mode (380 kHz) generates high compressive stress (around 500 MPa) due to ion bombardment and, as a result, densification of the layer achieved. Temperature can decrease the compressive value of the stress (due to annealing effect). A low etching rate of the amorphous silicon carbide layer was noticed for wet etching in KOH 30% at 80 o C (around 13 A/min) while in HF 49% the layer is practically inert. A very slow etching rate of amorphous silicon carbide layer in XeF 2 -7 A/min- was observed. The paper presents an example of this application: PECVD-amorphous silicon carbide cantilevers fabricated using surface micromachining by dry-released technique in XeF 2

  17. Geostatistics and multivariate analysis as a tool to characterize volcaniclastic deposits: Application to Nevado de Toluca volcano, Mexico

    Science.gov (United States)

    Bellotti, F.; Capra, L.; Sarocchi, D.; D'Antonio, M.

    2010-03-01

    Grain size analysis of volcaniclastic deposits is mainly used to study flow transport and depositional processes, in most cases by comparing some statistical parameters and how they change with distance from the source. In this work the geospatial and multivariate analyses are presented as a strong adaptable geostatistical tool applied to volcaniclastic deposits in order to provide an effective and relatively simple methodology for texture description, deposit discrimination and interpretation of depositional processes. We choose the case of Nevado de Toluca volcano (Mexico) due to existing knowledge of its geological evolution, stratigraphic succession and spatial distribution of volcaniclastic units. Grain size analyses and frequency distribution curves have been carried out to characterize and compare the 28-ka block-and-ash flow deposit associated to a dome destruction episode, and the El Morral debris avalanche deposit originated from the collapse of the south-eastern sector of the volcano. The geostatistical interpolation of sedimentological data allows to realize bidimensional maps draped over the volcano topography, showing the granulometric distribution, sorting and fine material concentration into the whole deposit with respect to topographic changes. In this way, it is possible to analyze a continuous surface of the grain size distribution of volcaniclastic deposits and better understand flow transport processes. The application of multivariate statistic analysis (discriminant function) indicates that this methodology could be useful in discriminating deposits with different origin or different depositional lithofacies within the same deposit. The proposed methodology could be an interesting approach to sustain more classical analysis of volcaniclastic deposits, especially where a clear field classification appears problematic because of a homogeneous texture of the deposits or their scarce and discontinuous outcrops. Our study is an example of the

  18. Deposition and Resuspension of Particles

    DEFF Research Database (Denmark)

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.

    A new experimental set-up to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airBorne dust concentration considerably. As a basis for developing methods to eliminate dust related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension....

  19. Modern processes of palynomorph deposition at lakes of the northern region of the Rio de Janeiro State, Brazil.

    Science.gov (United States)

    Luz, Cynthia F P da; Barth, Ortrud M; Silva, Cleverson G

    2010-09-01

    Palynological analysis of pollen, Pteridophyta spores and algae deposited in the superficial sediments at Lagoa de Cima and Lagoa do Campelo Lakes, located in the north of Rio de Janeiro state, was used to determine the spatial variation of the palynomorphs deposition. A total of 67 pollen types were identified at Lagoa de Cima, with an expressive contribution of regional arboreous taxa, hydrophytes and ruderal plants of the pastureland. The depositional pattern of palynomorphs depends on the fluvial leakage, the proximity of the local sedimentation to the inlet of the Imbé and Urubu Rivers and the bathymetry of lake bottom. The highest concentrations of palynomorphs were observed in the decentralized and less deeper area, without the interference of the northeastern wind. At Lagoa do Campelo, a total of 58 pollen types were identified, among which the majority of the pollen grains came from hydrophytes, with the highest concentrations found along the northeastern shore. The southeastern shore showed high percentages of pollen and spores with degraded exine and mechanical damage, due to the transport through the lake by the currents caused by the wind, confirmed by the depositional trend of damaged palinomorphs along the same direction as the prevailing winds.

  20. On the physical and chemical details of alumina atomic layer deposition: A combined experimental and numerical approach

    International Nuclear Information System (INIS)

    Pan, Dongqing; Ma, Lulu; Xie, Yuanyuan; Yuan, Chris; Jen, Tien Chien

    2015-01-01

    Alumina thin film is typically studied as a model atomic layer deposition (ALD) process due to its high dielectric constant, high thermal stability, and good adhesion on various wafer surfaces. Despite extensive applications of alumina ALD in microelectronics industries, details on the physical and chemical processes are not yet well understood. ALD experiments are not able to shed adequate light on the detailed information regarding the transient ALD process. Most of current numerical approaches lack detailed surface reaction mechanisms, and their results are not well correlated with experimental observations. In this paper, the authors present a combined experimental and numerical study on the details of flow and surface reactions in alumina ALD using trimethylaluminum and water as precursors. Results obtained from experiments and simulations are compared and correlated. By experiments, growth rate on five samples under different deposition conditions is characterized. The deposition rate from numerical simulation agrees well with the experimental results. Details of precursor distributions in a full cycle of ALD are studied numerically to bridge between experimental observations and simulations. The 3D transient numerical model adopts surface reaction kinetics and mechanisms based on atomic-level studies to investigate the surface deposition process. Surface deposition is shown as a strictly self-limited process in our numerical studies. ALD is a complex strong-coupled fluid, thermal and chemical process, which is not only heavily dependent on the chemical kinetics and surface conditions but also on the flow and material distributions

  1. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2007-02-28

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  2. Natural radiation in mineral sands deposits in Vietnam and problem of radiological protection

    International Nuclear Information System (INIS)

    Hung, Bui Van; Duong, Pham Van; Dien, Pham Quang; Quang, Nguyen Hao

    1993-01-01

    There are about 40 mineral sands deposits located along the Vietnamese coast between Binh Ngoc in the North to Vung Tau in the South of the country. Most of them are being exploited for both, domestic and foreign markets. It has been assessed that the natural gamma background levels over the deposits vary between 0.2 to over 10μGy/h. This wide range indicates that the level of naturally occurring radioactivity in the deposits will warrant its further investigations due to the likelihood of an occurrence of elevated radioactivity levels in mineral processing plants. This paper presents results of the following preliminary investigations: determinations of U and Th concentrations in mineral sands ore samples from several deposits, and determinations of U and Th concentrations in various ilmenite concentrate fractions and secondary separation tailings from Ha Tinh province. The radioactivity levels in the heavy minerals and the labour intensive mineral separation technology currently applied will warrant closer attention to be paid to mineral processing and waste handling in order to improve both, occupational and environmental radiological aspects of the operations. 4 refs., 3 tabs., 1 fig

  3. Hierarchy of facies of pyroclastic flow deposits generated by Laacher See type eruptions

    Science.gov (United States)

    Freundt, A.; Schmincke, H.-U.

    1985-04-01

    The upper Quaternary pyroclastic flow deposits of Laacher See volcano show compositional and structural facies variations on four different scales: (1) eruptive units of pyroclastic flows, composed of many flow units; (2) depositional cycles of as many as five flow units; flow units containing (3) regional intraflow-unit facies; and (4) local intraflow-unit subfacies. These facies can be explained by successively overlapping processes beginning in the magma column and ending with final deposition. The pyroclastic flow deposits thus reflect major aspects of the eruptive history of Laacher See volcano: (a) drastic changes in eruptive mechanism due to increasing access of water to the magma chamber and (b) change in chemical composition and crystal and gas content as evacuation of a compositionally zoned magma column progressed. The four scales of facies result from four successive sets of processes: (1) differentiation in the magma column and external factors governing the mechanism of eruption; (2) temporal variations of factors inducing eruption column collapse; (3) physical conditions in the eruption column and the way in which its collapse proceeds; and (4) interplay of flow-inherent and morphology-induced transport mechanics.

  4. Results of potential exposure assessments during the maintenance and cleanout of deposition equipment

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, E., E-mail: eric.zimmermann@cea.fr; Derrough, S.; Locatelli, D.; Durand, C.; Fromaget, J. L.; Lefranc, E.; Ravanel, X.; Garrione, J. [Nanosafety Platform, CEA, DRT (France)

    2012-10-15

    This study is a compilation of results obtained during the cleanout of deposition equipment such as chemical vapor deposition or physical vapor deposition The measurement campaigns aimed to evaluate the potential exposure to nanoaerosols in the occupational environment and were conducted in the workspace. The characterization of aerosols includes measurements of the concentration using condensation particle counters and measurements of the size distribution using fast mobility particle sizer, scanning mobility particle sizer, and electrical low pressure impactor (ELPI). Particles were sampled using collection membranes placed on the ELPIs stages. The samples were analyzed with an SEM-EDS to provide information including size, shape, agglomeration state, and the chemical composition of the particles. The majority of the time, no emission of nanoparticles (NPs) was measured during the use of the molecular deposition equipment or when opening the chambers, mainly due to the enclosed processes. On the other hand, the maintenance of the equipment, and especially the cleanout step, could induce high concentrations of NPs in the workplace following certain processes. Values of around 1 million particles/cm{sup 3} were detected with a size distribution including a high concentration of particles around 10 nm.

  5. High-rate anisotropic ablation and deposition of polytetrafluoroethylene using synchrotron radiation process

    International Nuclear Information System (INIS)

    Inayoshi, Muneto; Ikeda, Masanobu; Hori, Masaru; Goto, Toshio; Hiramatsu, Mineo; Hiraya, Atsunari.

    1995-01-01

    Both anisotropic ablation and thin film formation of polytetrafluoroethylene (PTFE) were successfully demonstrated using synchrotron radiation (SR) irradiation of PTFE, that is, the SR ablation process. Anisotropic ablation by the SR irradiation was performed at an extremely high rate of 3500 μm/min at a PTFE target temperature of 200degC. Moreover, a PTFE thin film was formed at a high rate of 2.6 μm/min using SR ablation of PTFE. The chemical structure of the deposited film was similar to that of the PTFE target as determined from Fourier transform infrared absorption spectroscopy (FT-IR) analysis. (author)

  6. Ultraviolet optical properties of aluminum fluoride thin films deposited by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennessy, John, E-mail: john.j.hennessy@jpl.nasa.gov; Jewell, April D.; Balasubramanian, Kunjithapatham; Nikzad, Shouleh [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2016-01-15

    Aluminum fluoride (AlF{sub 3}) is a low refractive index material with promising optical applications for ultraviolet (UV) wavelengths. An atomic layer deposition process using trimethylaluminum and anhydrous hydrogen fluoride has been developed for the deposition of AlF{sub 3} at substrate temperatures between 100 and 200 °C. This low temperature process has resulted in thin films with UV-optical properties that have been characterized by ellipsometric and reflection/transmission measurements at wavelengths down to 200 nm. The optical loss for 93 nm thick films deposited at 100 °C was measured to be less than 0.2% from visible wavelengths down to 200 nm, and additional microstructural characterization demonstrates that the films are amorphous with moderate tensile stress of 42–105 MPa as deposited on silicon substrates. X-ray photoelectron spectroscopy analysis shows no signature of residual aluminum oxide components making these films good candidates for a variety of applications at even shorter UV wavelengths.

  7. One-step microwave plasma enhanced chemical vapor deposition (MW-PECVD) for transparent superhydrophobic surface

    Science.gov (United States)

    Thongrom, Sukrit; Tirawanichakul, Yutthana; Munsit, Nantakan; Deangngam, Chalongrat

    2018-02-01

    We demonstrate a rapid and environmental friendly fabrication technique to produce optically clear superhydrophobic surfaces using poly (dimethylsiloxane) (PDMS) as a sole coating material. The inert PDMS chain is transformed into a 3-D irregular solid network through microwave plasma enhanced chemical vapor deposition (MW-PECVD) process. Thanks to high electron density in the microwave-activated plasma, coating can be done in just a single step with rapid deposition rate, typically much shorter than 10 s. Deposited layers show excellent superhydrophobic properties with water contact angles of ∼170° and roll-off angles as small as ∼3°. The plasma-deposited films can be ultrathin with thicknesses under 400 nm, greatly diminishing the optical loss. Moreover, with appropriate coating conditions, the coating layer can even enhance the transmission over the entire visible spectrum due to a partial anti-reflection effect.

  8. Interface charge trapping induced flatband voltage shift during plasma-enhanced atomic layer deposition in through silicon via

    Science.gov (United States)

    Li, Yunlong; Suhard, Samuel; Van Huylenbroeck, Stefaan; Meersschaut, Johan; Van Besien, Els; Stucchi, Michele; Croes, Kristof; Beyer, Gerald; Beyne, Eric

    2017-12-01

    A Through Silicon Via (TSV) is a key component for 3D integrated circuit stacking technology, and the diameter of a TSV keeps scaling down to reduce the footprint in silicon. The TSV aspect ratio, defined as the TSV depth/diameter, tends to increase consequently. Starting from the aspect ratio of 10, to improve the TSV sidewall coverage and reduce the process thermal budget, the TSV dielectric liner deposition process has evolved from sub-atmospheric chemical vapour deposition to plasma-enhanced atomic layer deposition (PE-ALD). However, with this change, a strong negative shift in the flatband voltage is observed in the capacitance-voltage characteristic of the vertical metal-oxide-semiconductor (MOS) parasitic capacitor formed between the TSV copper metal and the p-Si substrate. And, no shift is present in planar MOS capacitors manufactured with the same PE-ALD oxide. By comparing the integration process of these two MOS capacitor structures, and by using Elastic Recoil Detection to study the elemental composition of our films, it is found that the origin of the negative flatband voltage shift is the positive charge trapping at the Si/SiO2 interface, due to the positive PE-ALD reactants confined to the narrow cavity of high aspect ratio TSVs. This interface charge trapping effect can be effectively mitigated by high temperature annealing. However, this is limited in the real process due to the high thermal budget. Further investigation on liner oxide process optimization is needed.

  9. Recent progress of obliquely deposited thin films for industrial applications

    Science.gov (United States)

    Suzuki, Motofumi; Itoh, Tadayoshi; Taga, Yasunori

    1999-06-01

    More than 10 years ago, birefringent films of metal oxides were formed by oblique vapor deposition and investigated with a view of their application to optical retardation plates. The retardation function of the films was explained in terms of the birefringence caused by the characteristic anisotropic nanostructure inside the films. These films are now classified in the genre of the so-called sculptured thin films. However, the birefringent films thus prepared are not yet industrialized even now due to the crucial lack of the durability and the yield of products. In this review paper, we describe the present status of application process of the retardation films to the information systems such as compact disc and digital versatile disc devices with a special emphasis on the uniformity of retardation properties in a large area and the stability of the optical properties of the obliquely deposited thin films. Finally, further challenges for wide application of the obliquely deposited thin films are also discussed.

  10. Silver deposition on titanium surface by electrochemical anodizing process reduces bacterial adhesion of Streptococcus sanguinis and Lactobacillus salivarius.

    Science.gov (United States)

    Godoy-Gallardo, Maria; Rodríguez-Hernández, Ana G; Delgado, Luis M; Manero, José M; Javier Gil, F; Rodríguez, Daniel

    2015-10-01

    The aim of this study was to determine the antibacterial properties of silver-doped titanium surfaces prepared with a novel electrochemical anodizing process. Titanium samples were anodized with a pulsed process in a solution of silver nitrate and sodium thiosulphate at room temperature with stirring. Samples were processed with different electrolyte concentrations and treatment cycles to improve silver deposition. Physicochemical properties were determined by X-ray photoelectron spectroscopy, contact angle measurements, white-light interferometry, and scanning electron microscopy. Cellular cytotoxicity in human fibroblasts was studied with lactate dehydrogenase assays. The in vitro effect of treated surfaces on two oral bacteria strains (Streptococcus sanguinis and Lactobacillus salivarius) was studied with viable bacterial adhesion measurements and growth curve assays. Nonparametric statistical Kruskal-Wallis and Mann-Whitney U-tests were used for multiple and paired comparisons, respectively. Post hoc Spearman's correlation tests were calculated to check the dependence between bacteria adhesion and surface properties. X-ray photoelectron spectroscopy results confirmed the presence of silver on treated samples and showed that treatments with higher silver nitrate concentration and more cycles increased the silver deposition on titanium surface. No negative effects in fibroblast cell viability were detected and a significant reduction on bacterial adhesion in vitro was achieved in silver-treated samples compared with control titanium. Silver deposition on titanium with a novel electrochemical anodizing process produced surfaces with significant antibacterial properties in vitro without negative effects on cell viability. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. MAPLE deposition of nanomaterials

    International Nuclear Information System (INIS)

    Caricato, A.P.; Arima, V.; Catalano, M.; Cesaria, M.; Cozzoli, P.D.; Martino, M.; Taurino, A.; Rella, R.; Scarfiello, R.; Tunno, T.; Zacheo, A.

    2014-01-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  12. MAPLE deposition of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  13. Improving the technology of deposition using strip electrode

    Directory of Open Access Journals (Sweden)

    Сергій Володимирович Гулаков

    2017-07-01

    Full Text Available The behavior of the arc at the strip electrode tip is studied. It is shown that the arc is moving along the electrode tip due to periodic short-circuits of the arc gap. Thus, a new arc is excited at the point where short circuit occurred after a conductive bridge formed by molten metal is vanished due to a high welding current. This leads to an increase in the probability of defect formation in the deposited layer of workpiece under treatment. To improve deposited layer quality, it is suggested to identify the moments of short-circuits of the electrode to the base metal and to discharge the pre-charged capacitorat these instants, connecting it between the electrode and the product. High discharge current pulse speeds up the destruction of the molten metal bridge between electrode tip and workpiece, thus lowering the time needed for arc re-ignition and improving depostion process stability. A special automated equipment has been developed to implement this process. Capacitor discharge is done using power thyristor with series-connected inductance for limiting discharging current rate of rise and for limiting discharge current peak value such that it is not impairing thyristor reliability. The pre-charging of the capacitor is done by an auxiliary power supply. Several thyristor-capacitor networks can be used in parallel to allow for multiple current pulses mode and to reduce RMS currents in capacitors

  14. Development of data processing system for regional geophysical and geochemical exploration of sandstone-hosted uranium deposits based on ArcGIS Engine

    International Nuclear Information System (INIS)

    Han Shaoyang; Ke Dan; Hou Huiqun; Hu Shuiqing

    2010-01-01

    According to the data processing need of geophysical and geochemical exploration of sandstone-hosted uranium deposits, the function design of the regional geophysical and geochemical data processing system is completed in the paper. The geophysical and geochemical data processing software with powerful functions is also developed based on ArcGIS Engine which remedies the shortage of GIS software for performing the geophysical and geochemical data processing. The development technique route of system software and key techniques are introduced, and the development processes of system software are showed through some development examples. Application practices indicate that the interface of developed system software with friendly interface and utility functions, may quickly perform the data processing of regional geophysical and geochemical exploration and provide the helpful deep information for predicting metallogenic prospective areas of sandstone-hosted uranium deposits. The system software is of a great application foreground. (authors)

  15. Initial deposition mechanism of electroless nickel plating on AZ91D magnesium alloys

    International Nuclear Information System (INIS)

    Song, Y.; Shan, D.; Han, E.

    2006-01-01

    The pretreatment processes and initial deposition mechanism of electroless nickel plating on AZ91D magnesium alloy were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The results showed that alkaline cleaning could remove the greases and oils from the substrate surface. Acid etching could wipe off the metal chippings and oxides. The hydrofluoric acid activating process which could improve the adhesion of coating to substrate played a key role in the subsequent process of electroless nickel plating. The nickel coating was deposited preferentially on the primary α phase and then spread to the eutectic α phase and β phase. The nickel initially nucleated on the primary α phase by a replacement reaction, then grew depending on the autocatalysis function of nickel. The coating on the β phase displayed better adhesion than that on the α phase due to the nails fixing effect. (author)

  16. New approaches in geological studies of tsunami deposits

    Science.gov (United States)

    Szczucinski, Witold

    2017-04-01

    During the last dozen of years tsunamis have appeared to be the most disastrous natural process worldwide. The dramatic, large tsunamis on Boxing Day, 2004 in the Indian Ocean and on March 11, 2011 offshore Japan caused catastrophes listed as the worst in terms of the number of victims and the economic losses, respectively. In the aftermath, they have become a topic of high public and scientific interest. The record of past tsunamis, mainly in form of tsunami deposits, is often the only way to identify tsunami risk at a particular coast due to relatively low frequency of their occurrence. The identification of paleotsunami deposits is often difficult mainly because the tsunami deposits are represented by various sediment types, may be similar to storm deposits or altered by post-depositional processes. There is no simple universal diagnostic set of criteria that can be applied to interpret tsunami deposits with certainty. Thus, there is a need to develop new methods, which would enhance 'classical', mainly sedimentological and stratigraphic approach. The objective of the present contribution is to show recent progress and application of new approaches including geochemistry (Chagué-Goff et al. 2017) and paleogenetics (Szczuciński et al. 2016) in studies of geological impacts of recent tsunamis from various geographical regions, namely in monsoonal-tropical, temperate and polar zones. It is mainly based on own studies of coastal zones affected by 2004 Indian Ocean Tsunami in Thailand, 2011 Tohoku-oki tsunami and older paleotsunamis in Japan, catastrophic saltwater inundations at the coasts of Baltic Sea and 2000 landslide-generated tsunami in Vaigat Strait (west Greenland). The study was partly funded by Polish National Science Centre grant No. 2011/01/B/ST10/01553. Chagué-Goff C., Szczuciński W., Shinozaki T., 2017. Applications of geochemistry in tsunami research: A review. Earth-Science Reviews 165: 203-244. Szczuciński W., Pawłowska J., Lejzerowicz F

  17. Optical granulometric analysis of sedimentary deposits by color segmentation-based software: OPTGRAN-CS

    Science.gov (United States)

    Chávez, G. Moreno; Sarocchi, D.; Santana, E. Arce; Borselli, L.

    2015-12-01

    The study of grain size distribution is fundamental for understanding sedimentological environments. Through these analyses, clast erosion, transport and deposition processes can be interpreted and modeled. However, grain size distribution analysis can be difficult in some outcrops due to the number and complexity of the arrangement of clasts and matrix and their physical size. Despite various technological advances, it is almost impossible to get the full grain size distribution (blocks to sand grain size) with a single method or instrument of analysis. For this reason development in this area continues to be fundamental. In recent years, various methods of particle size analysis by automatic image processing have been developed, due to their potential advantages with respect to classical ones; speed and final detailed content of information (virtually for each analyzed particle). In this framework, we have developed a novel algorithm and software for grain size distribution analysis, based on color image segmentation using an entropy-controlled quadratic Markov measure field algorithm and the Rosiwal method for counting intersections between clast and linear transects in the images. We test the novel algorithm in different sedimentary deposit types from 14 varieties of sedimentological environments. The results of the new algorithm were compared with grain counts performed manually by the same Rosiwal methods applied by experts. The new algorithm has the same accuracy as a classical manual count process, but the application of this innovative methodology is much easier and dramatically less time-consuming. The final productivity of the new software for analysis of clasts deposits after recording field outcrop images can be increased significantly.

  18. Simulation of Deposition the Corrosion Waste in a Water Distribution System

    Directory of Open Access Journals (Sweden)

    Peráčková Jana

    2013-04-01

    Full Text Available In water distribution systems can be found particles of rust and other mechanical contaminants. The particles are deposited in locations where the low velocity of water flow. Where a can cause the pitting corrosion. Is a concern in the systems made of galvanized steel pipes. The contribution deals with CFD (Computational Fluid Dynamics simulations of water flow and particles deposition in water distribution system. CFD Simulations were compared with the corrosive deposits in real pipeline. Corrosion is a spontaneous process of destruction of metal material due to electrochemical reactions of metal with the aggressive surrounding. Electrochemical corrosion is caused by the thermodynamic instability of metal and therefore can not be completely suppress, it can only influence the speed of corrosion. The requirement is to keep metal properties during the whole its lifetime. Requested service lifetime the water pipe according to EN 806-2 is 50 years.

  19. Impact of Macro-economic Factors on Deposit Formation by Ukrainian Population

    Directory of Open Access Journals (Sweden)

    Shevaldina Valentyna H.

    2014-01-01

    Full Text Available The goal of the article is detection of interconnections between the common economic processes and formation of bank deposits by population. The article builds a correlation and regression model of complex assessment of interconnection between macro-economic factors, savings behaviour of population and level of deposits of population in banks for two hour horizons: short-term, which is characterised with deployment of crisis phenomena both in global economy and in Ukrainian economy and the medium-term one. The article characterises the most significant common macro-economic factors. In the result of the study the article establishes that Ukrainian population is oriented at short-term horizon when forming savings due to the uncertainty in future. In the medium-term prospective, savings of the population are formed basically under influence of macro-economic factors, while formation of deposits by Ukrainian population is mostly influenced by socio-psychological factors.

  20. Investigation of erosion and deposition on wall components of TEXTOR-94

    International Nuclear Information System (INIS)

    Wienhold, P.; Esser, H.G.; Kirschner, A.; Philipps, V.; Seggern, J. von; Ohya, K.; Rubel, M.

    1999-01-01

    The paper describes in the first part the formation of carbon flakes up to 10-20 μm thickness (average growth rate 2 nm/s) on the graphite tiles of the toroidal belt limiter. This occurred as a consequence of a slight change of the geometry and turned parts of the surface area from net erosion into net deposition zones. The possible influence of the morphology on this behaviour is discussed in the second part by means of an erosion experiment where the gradual disappearance of a boron substrate could be discriminated from the simultaneous carbon deposition on the surface. The two counter-acting processes co-exist within 10-30 μm distance and lead to an extremely non-uniform carbon deposition even in net erosion zones. The carbon agglomeration coincides with surface imperfections, e.g. grooves, but agglomeration by temperature enhanced mobility is not excluded. The changeover from net deposition to net erosion averaged over larger distances can still be observed and is due to the hydrogen and carbon fluxes in the SOL. This is confirmed by Monte-Carlo code calculations. (orig.)

  1. A unique laboratory test rig reduces the need for offshore tests to combat calcium naphthenate deposition in oilfield process equipment.

    Energy Technology Data Exchange (ETDEWEB)

    Mediaas, Heidi; Grande, Knut; Hustad, Britt-Marie; Hoevik, Kim Reidar; Kummernes, Hege; Nergaard, Bjoern; Vindstad, Jens Emil

    2006-03-15

    Producing and refining high-TAN crude oils introduces a number of challenges, among which calcium naphthenate deposition in process facilities is the most serious production issue. Until recently, the only option for studying chemicals and process parameters in order to prevent naphthenate deposition has been field tests. Statoil has now developed a small scale pilot plant where these experiments can be performed in the laboratory at Statoil's Research and Technology Center in Trondheim, Norway. The results from the pilot plant are in full agreement with the extensive naphthenate experience obtained from almost 9 years operation of the Heidrun oilfield. The design and operational procedures for this test facility are based on the recent discovery by Statoil and ConocoPhillips of the ARN acid. The ARN acid is a prerequisite for calcium naphthenate deposition. The new continuous flow pilot plant, the Naphthenate Rig, is used to develop new environmental friendly naphthenate inhibitors and to optimize process operating conditions. Since it operates on real crudes the need for field tests in qualifying new naphthenate inhibitors is reduced. To the best of our knowledge, the rig is the first of its kind in the world. (Author)

  2. Method for deposition of a conductor in integrated circuits

    Science.gov (United States)

    Creighton, J. Randall; Dominguez, Frank; Johnson, A. Wayne; Omstead, Thomas R.

    1997-01-01

    A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten.

  3. Carbon Deposition Diagnostics for Reliability and State-of-Health Assessment of SOFC

    DEFF Research Database (Denmark)

    Ploner, A.; Hagen, A.; Hauch, A.

    2018-01-01

    -YSZ-supported cell under steam reforming conditions by stopping the steam supply and investigates the cell voltage and temperature responses due to this fault. Simultaneously, time-dependent electrochemical impedance spectroscopy (EIS) monitoring during cell operation was performed which could be correlated to two...... processes, one mainly originating from support layer and another from the active anode layer of the cell in a Ni-YSZ supported cell. Monitoring via EIS may therefore be used to allow recognition of carbon deposition in due course and give the opportunity to counteract before detrimental failure occurs....

  4. Optical thin film deposition

    International Nuclear Information System (INIS)

    Macleod, H.A.

    1979-01-01

    The potential usefulness in the production of optical thin-film coatings of some of the processes for thin film deposition which can be classified under the heading of ion-assisted techniques is examined. Thermal evaporation is the process which is virtually universally used for this purpose and which has been developed to a stage where performance is in almost all respects high. Areas where further improvements would be of value, and the possibility that ion-assisted deposition might lead to such improvements, are discussed. (author)

  5. Cu and Cu(Mn) films deposited layer-by-layer via surface-limited redox replacement and underpotential deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J.S., E-mail: jsfang@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Sun, S.L. [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Cheng, Y.L. [Department of Electrical Engineering, National Chi-Nan University, Nan-Tou 54561, Taiwan (China); Chen, G.S.; Chin, T.S. [Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

    2016-02-28

    Graphical abstract: - Abstract: The present paper reports Cu and Cu(Mn) films prepared layer-by-layer using an electrochemical atomic layer deposition (ECALD) method. The structure and properties of the films were investigated to elucidate their suitability as Cu interconnects for microelectronics. Previous studies have used primarily a vacuum-based atomic layer deposition to form a Cu metallized film. Herein, an entirely wet chemical process was used to fabricate a Cu film using the ECALD process by combining underpotential deposition (UPD) and surface-limited redox replacement (SLRR). The experimental results indicated that an inadequate UPD of Pb affected the subsequent SLRR of Cu and lead to the formation of PbSO{sub 4}. A mechanism is proposed to explain the results. Layer-by-layer deposition of Cu(Mn) films was successfully performed by alternating the deposition cycle-ratios of SLRR-Cu and UPD-Mn. The proposed self-limiting growth method offers a layer-by-layer wet chemistry-based deposition capability for fabricating Cu interconnects.

  6. Uranium deposits in the metamorphic basement of the Rouergue massif. Genesis and extension of related albitization processes

    International Nuclear Information System (INIS)

    Schmitt, J.M.

    1982-02-01

    Albitization processes in the Rouergue metamorphic basement, probably Permian aged is evidenced. Late development of uranium orebodies occured within albitized zones. The detection of the latter serves as a highly valuable indirect guide for prospecting this type of deposits in a metamorphic basement [fr

  7. Data on nearshore wave process and surficial beach deposits, central Tamil Nadu coast, India.

    Science.gov (United States)

    Joevivek, V; Chandrasekar, N

    2017-08-01

    The chronicles of nearshore morphology and surficial beach deposits provide valuable information about the nature of the beach condition and the depositional environment. It imparts an understanding about the spatial and temporal relationship of nearshore waves and its influence over the distribution of beach sediments. This article contains data about wave and sediment dynamics of the ten sandy beaches along the central Tamil Nadu coast, India. This present dataset comprises nearshore wave parameters, breaker wave type, beach morphodynamic state, grain size distribution and weight percentage of heavy and light mineral distribution. The dataset will figure out the beach morphology and hydrodynamic condition with respect to the different monsoonal season. This will act as a field reference to realize the coastal dynamics in an open sea condition. The nearshore entities were obtained from the intensive field survey between January 2011 and December 2011, while characteristics of beach sediments are examined by the chemical process in the laboratory environment.

  8. 20 CFR 670.545 - How does Job Corps ensure that students receive due process in disciplinary actions?

    Science.gov (United States)

    2010-04-01

    ... receive due process in disciplinary actions? 670.545 Section 670.545 Employees' Benefits EMPLOYMENT AND... process in disciplinary actions? The center operator must ensure that all students receive due process in disciplinary proceedings according to procedures developed by the Secretary. These procedures must include, at...

  9. Precambrian uranium deposits as a possible source of uranium for the European Variscan deposits

    International Nuclear Information System (INIS)

    Mineeva, I.G.; Klochkov, A.S.

    2002-01-01

    The Precambrian uranium deposits have been studied on the territory of Baltic and Ukrainian shields. The primary Early Proterozoic complex Au-U deposits originated in granite-greenstone belts as a result of their evolution during continental earth crust formation by prolonged rift genesis. The greenstone belts are clues for revealing ancient protoriftogenic structures. The general regularities of uranium deposition on Precambrian shields are also traceable in Variscan uranium deposits from the Bohemian massif. The Variscan period of uranium ore formation is connected with a polychronous rejuvenation of ancient riftogenous systems and relatively younger processes of oil and gas formation leading to the repeated mobilization of U from destroyed Proterozoic and Riphean uranium deposits. (author)

  10. Interpretation of sedimentological processes of coarse-grained deposits applying a novel combined cluster and discriminant analysis

    Science.gov (United States)

    Farics, Éva; Farics, Dávid; Kovács, József; Haas, János

    2017-10-01

    The main aim of this paper is to determine the depositional environments of an Upper-Eocene coarse-grained clastic succession in the Buda Hills, Hungary. First of all, we measured some commonly used parameters of samples (size, amount, roundness and sphericity) in a much more objective overall and faster way than with traditional measurement approaches, using the newly developed Rock Analyst application. For the multivariate data obtained, we applied Combined Cluster and Discriminant Analysis (CCDA) in order to determine homogeneous groups of the sampling locations based on the quantitative composition of the conglomerate as well as the shape parameters (roundness and sphericity). The result is the spatial pattern of these groups, which assists with the interpretation of the depositional processes. According to our concept, those sampling sites which belong to the same homogeneous groups were likely formed under similar geological circumstances and by similar geological processes. In the Buda Hills, we were able to distinguish various sedimentological environments within the area based on the results: fan, intermittent stream or marine.

  11. Coating of diamond-like carbon nanofilm on alumina by microwave plasma enhanced chemical vapor deposition process.

    Science.gov (United States)

    Rattanasatien, Chotiwan; Tonanon, Nattaporn; Bhanthumnavin, Worawan; Paosawatyanyong, Boonchoat

    2012-01-01

    Diamond-like carbon (DLC) nanofilms with thickness varied from under one hundred to a few hundred nanometers have been successfully deposited on alumina substrates by microwave plasma enhanced chemical vapor deposition (MW-PECVD) process. To obtain dense continuous DLC nanofilm coating over the entire sample surface, alumina substrates were pre-treated to enhance the nucleation density. Raman spectra of DLC films on samples showed distinct diamond peak at around 1332 cm(-1), and the broad band of amorphous carbon phase at around 1550 cm(-1). Full width at half maximum height (FWHM) values indicated good formation of diamond phase in all films. The result of nano-indentation test show that the hardness of alumina samples increase from 7.3 +/- 2.0 GPa in uncoated samples to 15.8 +/- 4.5-52.2 +/- 2.1 GPa in samples coated with DLC depending on the process conditions. It is observed that the hardness values are still in good range although the thickness of the films is less than a hundred nanometer.

  12. Reconstructing depositional processes and history from reservoir stratigraphy: Englebright Lake, Yuba River, northern California

    Science.gov (United States)

    Snyder, N.P.; Wright, S.A.; Alpers, Charles N.; Flint, L.E.; Holmes, C.W.; Rubin, D.M.

    2006-01-01

    Reservoirs provide the opportunity to link watershed history with its stratigraphic record. We analyze sediment cores from a northern California reservoir in the context of hydrologic history, watershed management, and depositional processes. Observations of recent depositional patterns, sediment-transport calculations, and 137CS geochronology support a conceptual model in which the reservoir delta progrades during floods of short duration (days) and is modified during prolonged (weeks to months) drawdowns that rework topset beds and transport sand from topsets to foresets. Sediment coarser than 0.25-0.5 mm. deposits in foresets and topsets, and finer material falls out of suspension as bottomset beds. Simple hydraulic calculations indicate that fine sand (0.063-0.5 mm) is transported into the distal bottomset area only during floods. The overall stratigraphy suggests that two phases of delta building occurred in the reservoir. The first, from dam construction in 1940 to 1970, was heavily influenced by annual, prolonged >20 m drawdowns of the water level. The second, built on top of the first, reflects sedimentation from 1970 to 2002 when the influence of drawdowns was less. Sedimentation rates in the central part of the reservoir have declined ???25% since 1970, likely reflecting a combination of fewer large floods, changes in watershed management, and winnowing of stored hydraulic mining sediment. Copyright 2006 by the American Geophysical Union.

  13. Electrochemically Deposited Nickel Membranes; Process-Microstructure-Property Relationships

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl; Pantleon, Karen; Somers, Marcel A.J.

    2003-01-01

    This paper reports on the manufacturing, surface morphology, internal structure and mechanical properties of Ni-foils used as membranes in reference-microphones. Two types of foils, referred to as S-type and 0-type foils, were electrochemically deposited from a Watts-type electrolyte, with (S...

  14. The due-diligence process of purchasing or buying into a dental practice.

    Science.gov (United States)

    Conner, Vincent L

    2003-01-01

    A due-diligence or evaluation process is necessary when assessing a practice purchase opportunity. The standards for assessing the investment remain the same whether the buyer is purchasing a practice outright or buying a co-ownership interest.

  15. Hot-wire chemical vapour deposition of carbon nanotubes

    CSIR Research Space (South Africa)

    Cummings, FR

    2006-07-01

    Full Text Available ablation of graphite, carbon-arc discharge and chemical vapour deposition (CVD). However, some of these techniques have been shown to be expensive due to high deposition temperatures and are not easily controllable. Recently hot-wire chemical vapour...

  16. Sea-level proxies in Holocene raised beach ridge deposits (Greenland) revealed by ground-penetrating radar.

    Science.gov (United States)

    Nielsen, Lars; Bendixen, Mette; Kroon, Aart; Hede, Mikkel Ulfeldt; Clemmensen, Lars B; Weβling, Ronny; Elberling, Bo

    2017-04-19

    Identification of sea-level proxies is important for reconstruction of past sea-level variation. Methods for reconstructing Holocene relative sea-level curves are crucial for quantification of the impact of Greenland ice thickness variation on global sea level and vertical land movement. Arctic beach ridges constitute important potential archives of sea-level variation. However, their surface morphology may have undergone modification since deposition due to freezing/thawing processes and erosion, and their morphology may therefore not be trustworthy for sea-level reconstruction. Therefore, geophysical imaging is used to examine the internal structures of the beach ridges and to define a sea-level proxy unaffected by surface processes. The GPR reflections from study sites in West and South Greenland show deposition of beachface deposits and upper shoreface deposits; the contact between steeply dipping beachface reflections and less-dipping shoreface reflections is used as sea-level proxy. Numerous points are identified along GPR transects facilitating reconstruction of relative sea-level variation of hitherto unprecedented resolution. Erosional events and deformation caused by freezing/thawing processes are clearly delineated. The approach constitutes a solid base for reconstruction of relative sea-level curves affected by a well-defined vertical land movement history since the studied beach ridge systems represent long time intervals and only relatively small spatial extents.

  17. Photocatalytic evaluation of self-assembled porous network structure of ferric oxide film fabricated by dry deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yunchan; Kim, Hyungsub; Lee, Geon-Yong; Pawar, Rajendra C.; Lee, Jai-Sung; Lee, Caroline Sunyong, E-mail: sunyonglee@hanyang.ac.kr

    2016-09-15

    Ferric oxide powder in the alpha phase (α-Fe{sub 2}O{sub 3}) was deposited on an aluminum oxide (Al{sub 2}O{sub 3}) substrate by a nanoparticle deposition system using the dry deposition method. X-ray diffraction (XRD) images confirmed that the phase of the deposited α-Fe{sub 2}O{sub 3} did not change. The deposited α-Fe{sub 2}O{sub 3} was characterized in terms of its microstructure using scanning electron microscopy (SEM). A porous network microstructure formed when small agglomerates of Fe{sub 2}O{sub 3} (SAF) were deposited. The deposition and formation mechanism of the microstructure were investigated using SEM and three-dimensional (3D) profile analysis. First, a dense coating layer formed when the film was thinner than the particle size. After that, as the film thickness increased to over 5 μm, the porous network structure formed by excavating the surface of the coating layer as it was bombarded by particles. Rhodamine B (RhB) was degraded after 6 h of exposure to the Fe{sub 2}O{sub 3} coating layer with SAF, which has good photocatalytic activity and a high porous network structure. The kinetic rate constants of the SAF and large agglomerates of Fe{sub 2}O{sub 3} (LAF) were calculated to be 0.197(h{sup −1}) and 0.128(h{sup −1}), respectively, based on the absorbance results. Using linear sweep voltammetry, we confirmed that the photoelectric effect occurred in the coating layer by measuring the resulting current under illuminated and dark conditions. - Graphical abstract: Self-assembled porous photocatalytic film fabricated by dry deposition method for water purification. - Highlights: • Different sizes of Fe{sub 2}O{sub 3} agglomerates were used to form porous network structure. • Fe{sub 2}O{sub 3} agglomerate particles were deposited using solvent-free process. • Self-assembled porous network microstructure formed better with small agglomerates of Fe{sub 2}O{sub 3}. • Fabricated porous network structure showed its potential to be used

  18. Thermal Vapor Deposition and Characterization of Polymer-Ceramic Nanoparticle Thin Films and Capacitors

    Science.gov (United States)

    Iwagoshi, Joel A.

    Research on alternative energies has become an area of increased interest due to economic and environmental concerns. Green energy sources, such as ocean, wind, and solar power, are subject to predictable and unpredictable generation intermittencies which cause instability in the electrical grid. This problem could be solved through the use of short term energy storage devices. Capacitors made from composite polymer:nanoparticle thin films have been shown to be an economically viable option. Through thermal vapor deposition, we fabricated dielectric thin films composed of the polymer polyvinylidine fluoride (PVDF) and the ceramic nanoparticle titanium dioxide (TiO2). Fully understanding the deposition process required an investigation of electrode and dielectric film deposition. Film composition can be controlled by the mass ratio of PVDF:TiO2 prior to deposition. An analysis of the relationship between the ratio of PVDF:TiO2 before and after deposition will improve our understanding of this novel deposition method. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy were used to analyze film atomic concentrations. The results indicate a broad distribution of deposited TiO2 concentrations with the highest deposited amount at an initial mass concentration of 17% TiO2. The nanoparticle dispersion throughout the film is analyzed through atomic force microscopy and energy dispersive x-ray spectroscopy. Images from these two techniques confirm uniform TiO2 dispersion with cluster size less than 300 nm. These results, combined with spectroscopic analysis, verify control over the deposition process. Capacitors were fabricated using gold parallel plates with PVDF:TiO 2 dielectrics. These capacitors were analyzed using the atomic force microscope and a capacohmeter. Atomic force microscope images confirm that our gold films are acceptably smooth. Preliminary capacohmeter measurements indicate capacitance values of 6 nF and break down voltages of 2.4 V

  19. Formation, Sintering and Removal of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi

    conditions in laboratory-scale setups. Deposit formation was simulated in an Entrained Flow Reactor, to investigate the effect of operating conditions and ash chemistry on the rate of deposit formation. Experiments were performed using model biomass fly ash, prepared from mixtures of K2Si4O9, KCl, K2SO4, Ca....... Moreover, biomass ash deposits may cause severe corrosion of boiler surfaces. Therefore, reducing deposit formation and timely deposit removal are essential for optimal boiler operation. The formation, sintering and removal of boiler deposits has been investigated in this PhD project, by simulating boiler...... temperature increased the sticking probability of the fly ash particles/deposit surface, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, it was observed...

  20. Review of progress in pulsed laser deposition and using Nd:YAG laser in processing of high Tc superconductors

    International Nuclear Information System (INIS)

    Chen, C.W.; Mukherjee, K.

    1993-01-01

    The current progress in pulsed laser ablation of high-temperature superconductors is reviewed with emphasis on the effect of pulse-width and wavelength, nature of the plasma plume, post-annealing and methods to improve quality of films grown at low temperature. An ion beam assisted millisecond pulsed laser vapor deposition process has been developed to fabricate YBa 2 Cu 3 O x high T. superconductor thin films. Solution to target overheating problem, effects of oxygen ion beam, properties of deposited films, and effect of silver buffer layer on YSZ substrate are presented. A new laser calcining process has been used to produce near single phase high T c superconductors of Bi-Pb-Sr-Ca-Cu-0 system. The total processing time was reduced to about 100 hours which is about half of that for conventional sintering. For this compound both resistance and magnetic susceptibility data showed an onset of superconducting transition at about 110K. A sharp susceptibility drop was observed above 106K. The zero resistance temperature was about 98K. High T c phase was formed via a different kinetic path in laser calcined sample compare with the conventionally processed sample

  1. Deposition and Characterization of TRISO Coating Layers

    International Nuclear Information System (INIS)

    Kim, Do Kyung; Kim, Min Woo; Lee, Hyeon Keun; Choi, Doo Jin; Kim, Jun Kyu; Cho, Sung Hyuk

    2008-03-01

    Both ZrC and SiC layers are crucial layers in TRISO coated fuel particles since they prevent diffusion of fission products and provide mechanical strength for the fuel particle. However, each layer has its own defects, so the purpose of this study is to complement such defects of these layers. In this study, we carried out thermodynamic simulations before actual experiments. With these simulation results, we deposited the ZrC layers on SiC/graphite substrates through CVD process. SiC films on graphite have different microstructures which are a hemispherical angular, domed top and faceted structure at different deposition temperature, respectively. According to the microstructures of SiC, preferred orientation, hardness and elastic modules of deposited ZrC layer were changed. TRISO particles. The fracture the SiC coating layer occurred by the tensile stress due to the traditional pressure vessel failure criteria. It is important to find fracture stress of SiC coating layer by the internal pressurization test method. The finite-element analysis was carried out to obtain the empirical equation of strength evaluation. By using this empirical equation, the mechanical properties of several types of SiC coating film with different microstructure and thicknesses will discussed

  2. Deposition and Characterization of TRISO Coating Layers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Kyung; Kim, Min Woo; Lee, Hyeon Keun [KAIST, Daejeon (Korea, Republic of); Choi, Doo Jin; Kim, Jun Kyu; Cho, Sung Hyuk [Younsei University, Seoul (Korea, Republic of)

    2008-03-15

    Both ZrC and SiC layers are crucial layers in TRISO coated fuel particles since they prevent diffusion of fission products and provide mechanical strength for the fuel particle. However, each layer has its own defects, so the purpose of this study is to complement such defects of these layers. In this study, we carried out thermodynamic simulations before actual experiments. With these simulation results, we deposited the ZrC layers on SiC/graphite substrates through CVD process. SiC films on graphite have different microstructures which are a hemispherical angular, domed top and faceted structure at different deposition temperature, respectively. According to the microstructures of SiC, preferred orientation, hardness and elastic modules of deposited ZrC layer were changed. TRISO particles. The fracture the SiC coating layer occurred by the tensile stress due to the traditional pressure vessel failure criteria. It is important to find fracture stress of SiC coating layer by the internal pressurization test method. The finite-element analysis was carried out to obtain the empirical equation of strength evaluation. By using this empirical equation, the mechanical properties of several types of SiC coating film with different microstructure and thicknesses will discussed.

  3. Progress in the Study of Coastal Storm Deposits

    Science.gov (United States)

    Xiong, Haixian; Huang, Guangqing; Fu, Shuqing; Qian, Peng

    2018-05-01

    Numerous studies have been carried out to identify storm deposits and decipher storm-induced sedimentary processes in coastal and shallow-marine areas. This study aims to provide an in-depth review on the study of coastal storm deposits from the following five aspects. 1) The formation of storm deposits is a function of hydrodynamic and sedimentary processes under the constraints of local geological and ecological factors. Many questions remain to demonstrate the genetic links between storm-related processes and a variety of resulting deposits such as overwash deposits, underwater deposits and hummocky cross-stratification (HCS). Future research into the formation of storm deposits should combine flume experiments, field observations and numerical simulations, and make full use of sediment source tracing methods. 2) Recently there has been rapid growth in the number of studies utilizing sediment provenance analysis to investigate the source of storm deposits. The development of source tracing techniques, such as mineral composition, magnetic susceptibility, microfossil and geochemical property, has allowed for better understanding of the depositional processes and environmental changes associated with coastal storms. 3) The role of extreme storms in the sedimentation of low-lying coastal wetlands with diverse ecosystem services has also drawn a great deal of attention. Many investigations have attempted to quantify widespread land loss, vertical marsh sediment accumulation and wetland elevation change induced by major hurricanes. 4) Paleostorm reconstructions based on storm sedimentary proxies have shown many advantages over the instrumental records and historic documents as they allow for the reconstruction of storm activities on millennial or longer time scales. Storm deposits having been used to establish proxies mainly include beach ridges and shelly cheniers, coral reefs, estuary-deltaic storm sequences and overwash deposits. Particularly over the past few

  4. Research on chemical vapor deposition processes for advanced ceramic coatings

    Science.gov (United States)

    Rosner, Daniel E.

    1993-01-01

    Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

  5. Depth-resolved detection and process dependence of traps at ultrathin plasma-oxidized and deposited SiO2/Si interfaces

    International Nuclear Information System (INIS)

    Brillson, L. J.; Young, A. P.; White, B. D.; Schaefer, J.; Niimi, H.; Lee, Y. M.; Lucovsky, G.

    2000-01-01

    Low-energy electron-excited nanoluminescence spectroscopy reveals depth-resolved optical emission associated with traps near the interface between ultrathin SiO 2 deposited by plasma-enhanced chemical vapor deposition on plasma-oxidized crystalline Si. These near-interface states exhibit a strong dependence on local chemical bonding changes introduced by thermal/gas processing, layer-specific nitridation, or depth-dependent radiation exposure. The depth-dependent results provide a means to test chemical and structural bond models used to develop advanced dielectric-semiconductor junctions. (c) 2000 American Vacuum Society

  6. Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure

    OpenAIRE

    Michael Arthur Cuiffo; Jeffrey Snyder; Alicia M. Elliott; Nicholas Romero; Sandhiya Kannan; Gary P. Halada

    2017-01-01

    Polylactic acid (PLA) is an organic polymer commonly used in fused deposition (FDM) printing and biomedical scaffolding that is biocompatible and immunologically inert. However, variations in source material quality and chemistry make it necessary to characterize the filament and determine potential changes in chemistry occurring as a result of the FDM process. We used several spectroscopic techniques, including laser confocal microscopy, Fourier transform infrared (FTIR) spectroscopy and pho...

  7. Nano/micro particle beam for ceramic deposition and mechanical etching

    International Nuclear Information System (INIS)

    Chun, Doo-Man; Kim, Min-Saeng; Kim, Min-Hyeng; Ahn, Sung-Hoon; Yeo, Jun-Cheol; Lee, Caroline Sunyong

    2010-01-01

    Nano/micro particle beam (NPB) is a newly developed ceramic deposition and mechanical etching process. Additive (deposition) and subtractive (mechanical etching) processes can be realized in one manufacturing process using ceramic nano/micro particles. Nano- or micro-sized powders are sprayed through the supersonic nozzle at room temperature and low vacuum conditions. According to the process conditions, the ceramic powder can be deposited on metal substrates without thermal damage, and mechanical etching can be conducted in the same process with a simple change of process conditions and powders. In the present work, ceramic aluminum oxide (Al 2 O 3 ) thin films were deposited on metal substrates. In addition, the glass substrate was etched using a mask to make small channels. Deposited and mechanically etched surface morphology, coating thickness and channel depth were investigated. The test results showed that the NPB provides a feasible additive and subtractive process using ceramic powders.

  8. Cold Spraying of Armstrong Process Titanium Powder for Additive Manufacturing

    Science.gov (United States)

    MacDonald, D.; Fernández, R.; Delloro, F.; Jodoin, B.

    2017-04-01

    Titanium parts are ideally suited for aerospace applications due to their unique combination of high specific strength and excellent corrosion resistance. However, titanium as bulk material is expensive and challenging/costly to machine. Production of complex titanium parts through additive manufacturing looks promising, but there are still many barriers to overcome before reaching mainstream commercialization. The cold gas dynamic spraying process offers the potential for additive manufacturing of large titanium parts due to its reduced reactive environment, its simplicity to operate, and the high deposition rates it offers. A few challenges are to be addressed before the additive manufacturing potential of titanium by cold gas dynamic spraying can be reached. In particular, it is known that titanium is easy to deposit by cold gas dynamic spraying, but the deposits produced are usually porous when nitrogen is used as the carrier gas. In this work, a method to manufacture low-porosity titanium components at high deposition efficiencies is revealed. The components are produced by combining low-pressure cold spray using nitrogen as the carrier gas with low-cost titanium powder produced using the Armstrong process. The microstructure and mechanical properties of additive manufactured titanium components are investigated.

  9. Preliminary results on adhesion improvement using Ion Beam Sputtering Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yonggi; Kim, Bomsok; Lee, Jaesang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Sputtering is an established technique for depositing films with smooth surfaces and interfaces and good thick control. Ejection of articles from a condensed matter due to impingement of high energy particles, termed as sputtering was observed as early as in 1852, however, it is only recently that the complex process of sputtering system. Coating adhesion and environmental stability of the ion beam sputtering deposition coatings performed very well. High-energy high-current ion beam thin film synthesis of adhesion problems can be solved by using. Enhancement of adhesion in thin film synthesis, using high energy and high current ion beam, of mobile phones, car parts and other possible applications in the related industry Alternative technology of wet chrome plating, considering environment and unit cost, for car parts and esthetic improvement on surface of domestic appliances.

  10. Preliminary results on adhesion improvement using Ion Beam Sputtering Deposition

    International Nuclear Information System (INIS)

    Kim, Yonggi; Kim, Bomsok; Lee, Jaesang

    2013-01-01

    Sputtering is an established technique for depositing films with smooth surfaces and interfaces and good thick control. Ejection of articles from a condensed matter due to impingement of high energy particles, termed as sputtering was observed as early as in 1852, however, it is only recently that the complex process of sputtering system. Coating adhesion and environmental stability of the ion beam sputtering deposition coatings performed very well. High-energy high-current ion beam thin film synthesis of adhesion problems can be solved by using. Enhancement of adhesion in thin film synthesis, using high energy and high current ion beam, of mobile phones, car parts and other possible applications in the related industry Alternative technology of wet chrome plating, considering environment and unit cost, for car parts and esthetic improvement on surface of domestic appliances

  11. Standard Setting as Psychometric Due Process: Going a Little Further Down an Uncertain Road.

    Science.gov (United States)

    Cizek, Gregory J.

    The concept of due process provides an analogy for the process of standard setting that emphasizes many of the procedural and substantive elements of the process over technical and statistical concerns. Surely such concerns can and should continue to be addressed. However, a sound rationale for standard setting does not rest on this foundation.…

  12. Laser deposition of HTSC films

    International Nuclear Information System (INIS)

    Sobol', Eh.N.; Bagratashvili, V.N.; Zherikhin, A.N.; Sviridov, A.P.

    1990-01-01

    Studies of the high-temperature superconducting (HTSC) films fabrication by the laser deposition are reviewed. Physical and chemical processes taking place during laser deposition are considered, such as the target evaporation, the material transport from the target to the substrate, the film growth on the substrate, thermochemical reactions and mass transfer within the HTSC films and their stability. The experimental results on the laser deposition of different HTSC ceramics and their properties investigations are given. The major technological issues are discussed including the deposition schemes, the oxygen supply, the target compositions and structure, the substrates and interface layers selection, the deposition regimes and their impact on the HTSC films properties. 169 refs.; 6 figs.; 2 tabs

  13. Method for depositing high-quality microcrystalline semiconductor materials

    Science.gov (United States)

    Guha, Subhendu [Bloomfield Hills, MI; Yang, Chi C [Troy, MI; Yan, Baojie [Rochester Hills, MI

    2011-03-08

    A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.

  14. Due Diligence Processes for Public Acquisition of Mining-Impacted Landscapes

    Science.gov (United States)

    Martin, E.; Monohan, C.; Keeble-Toll, A. K.

    2016-12-01

    The acquisition of public land is critical for achieving conservation and habitat goals in rural regions projected to experience continuously high rates of population growth. To ensure that public funds are utilized responsibly in the purchase of conservation easements appropriate due diligence processes must be established that limit landowner liability post-acquisition. Traditional methods of characterizing contamination in regions where legacy mining activities were prevalent may not utilize current scientific knowledge and understanding of contaminant fate, transport and bioavailability, and therefore are likely to have type two error. Agency prescribed assessment methods utilized under CERLA in many cases fail to detect contamination that presents liability issues by failing to require water quality sampling that would reveal offsite transport potential of contaminants posing human health risks, including mercury. Historical analysis can be used to inform judgmental sampling to identify hotspots and contaminants of concern. Land acquisition projects at two historic mine sites in Nevada County, California, the Champion Mine Complex and the Black Swan Preserve have established the necessity of re-thinking due diligence processes for mining-impacted landscapes. These pilot projects demonstrate that pre-acquisition assessment in the Gold Country must include judgmental sampling and evaluation of contaminant transport. Best practices using the current scientific knowledge must be codified by agencies, consultants, and NGOs in order to ensure responsible use of public funds and to safeguard public health.

  15. Annealing and deposition effects of the chemical composition of silicon rich nitride

    DEFF Research Database (Denmark)

    Andersen, Karin Nordström; Svendsen, Winnie Edith; Stimpel-Lindner, T.

    2005-01-01

    Silicon-rich nitride, deposited by LPCVD, is a low stress amorphous material with a high refractive index. After deposition the silicon-rich nitride thin film is annealed at temperatures above 1100 oC to break N-H bonds, which have absorption peaks in the wavelength band important for optical...... in optical waveguides. This means that the annealing temperature must be high enough to break the N-H bonds, but no so high as to produce clusters. Therefore, the process window for an annealing step lies between 1100 and 1150 oC. The chemical composition of amorphous silicon-rich nitride has been...... investigated by Rutherford back scattering (RBS) and X-ray photoelectron spectroscopy (XPS). The influence of deposition parameters and annealing temperatures on the stoichiometry and the chemical bonds will be discussed. The origin of the clusters has been found to be silicon due to severe silicon out...

  16. The Analytical Pragmatic Structure of Procedural Due Process: A Framework for Inquiry in Administrative Decision Making.

    Science.gov (United States)

    Fisher, James E.; Sealey, Ronald W.

    The study describes the analytical pragmatic structure of concepts and applies this structure to the legal concept of procedural due process. This structure consists of form, purpose, content, and function. The study conclusions indicate that the structure of the concept of procedural due process, or any legal concept, is not the same as the…

  17. An Alternative Low-Cost Process for Deposition of MCrAlY Bond Coats for Advanced Syngas/Hydrogen Turbine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying [Tennessee Technological Univ., Cookeville, TN (United States)

    2015-09-11

    The objective of this project was to develop and optimize MCrAlY bond coats for syngas/hydrogen turbine applications using a low-cost electrolytic codeposition process. Prealloyed CrAlY-based powders were codeposited into a metal matrix of Ni, Co or Ni-Co during the electroplating process, and a subsequent post-deposition heat treatment converted it to the MCrAlY coating. Our research efforts focused on: (1) investigation of the effects of electro-codeposition configuration and parameters on the CrAlY particle incorporation in the NiCo-CrAlY composite coatings; (2) development of the post-deposition heat treating procedure; (3) characterization of coating properties and evaluation of coating oxidation performance; (4) exploration of a sulfurfree electroplating solution; (5) cost analysis of the present electrolytic codeposition process. Different electro-codeposition configurations were investigated, and the rotating barrel system demonstrated the capability of depositing NiCo-CrAlY composite coatings uniformly on the entire specimen surface, with the CrAlY particle incorporation in the range 37-42 vol.%. Post-deposition heat treatment at 1000-1200 °C promoted interdiffusion between the CrAlY particles and the Ni-Co metal matrix, resulting in β/γ’/γ or β/γ’ phases in the heat-treated coatings. The results also indicate that the post-deposition heat treatment should be conducted at temperatures ≤1100 °C to minimize Cr evaporation and outward diffusion of Ti. The electro-codeposited NiCrAlY coatings in general showed lower hardness and surface roughness than thermal spray MCrAlY coatings. Coating oxidation performance was evaluated at 1000-1100 °C in dry and wet air environments. The initial electro-codeposited NiCoCrAlY coatings containing relatively high sulfur did not show good oxidation resistance. After modifications of the coating process, the cleaner NiCoCrAlY coating exhibited good oxidation performance at 1000 °C during the 2,000 1-h cyclic

  18. Reaction kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers

    International Nuclear Information System (INIS)

    Gokcen, Dincer; Bae, Sang-Eun; Brankovic, Stanko R.

    2011-01-01

    The study of the kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers is presented. The model system was Pt submonolayer deposition on Au(1 1 1) via red-ox replacement of Pb and Cu UPD monolayers on Au(1 1 1). The kinetics of a single replacement reaction was studied using the formalism of the comprehensive analytical model developed to fit the open circuit potential transients from deposition experiments. The practical reaction kinetics parameters like reaction half life, reaction order and reaction rate constant are determined and discussed with their relevance to design and control of deposition experiments. The effects of transport limitation and the role of the anions/electrolyte on deposition kinetics are investigated and their significance to design of effective deposition process is discussed.

  19. Parametric Investigation of the Isothermal Kinetics of Growth of Graphene on a Nickel Catalyst in the Process of Chemical Vapor Deposition of Hydrocarbons

    Science.gov (United States)

    Futko, S. I.; Shulitskii, B. G.; Labunov, V. A.; Ermolaeva, E. M.

    2016-11-01

    A kinetic model of isothermal synthesis of multilayer graphene on the surface of a nickel foil in the process of chemical vapor deposition, on it, of hydrocarbons supplied in the pulsed regime is considered. The dependences of the number of graphene layers formed and the time of their growth on the temperature of the process, the concentration of acetylene, and the thickness of the nickel foil were calculated. The regime parameters of the process of chemical vapor deposition, at which single-layer graphene and bi-layer graphene are formed, were determined. The dynamics of growth of graphene domains at chemical-vapor-deposition parameters changing in wide ranges was investigated. It is shown that the time dependences of the rates of growth of single-layer graphene and bi-layer graphene are nonlinear in character and that they are determined by the kinetics of nucleation and growth of graphene and the diffusion flow of carbon atoms in the nickel foil.

  20. Mediation and Due Process Procedures in Special Education: An Analysis of State Policies. Final Report. Project FORUM.

    Science.gov (United States)

    Ahearn, Eileen M.

    This survey of 50 states and 3 of 10 non-state U.S. jurisdictions concerning state due process procedures focuses mainly on the use of mediation as a form of dispute resolution that offers an alternative to due process hearings in special education. A background section discusses the definition of mediation and the mediation process. Survey…

  1. Particle deposition in low-speed, high-turbulence flows

    DEFF Research Database (Denmark)

    Reck, Mads; Larsen, Poul Scheel; Ullum, U.

    2002-01-01

    The experimental and numerical study considers the concentration of airborne particulate contaminants, such as spores of spoilage fungi, and their deposition on a surface, in a petri dish, and on a warm box-shaped product placed in a food-processing environment. Field measurements by standard...... field measurements. Particle deposition is shown to be associated with near-wall coherent structures. Flow reversal, simulated by impulsive start, is shown to give higher deposition rates than steady mean flows. Key word index: Spoilage fungi; spores; food processing plant; deposition flux; large eddy...

  2. Influence of the deposition geometry on the microstructure of sputter-deposited V-Al-C-N coatings

    Energy Technology Data Exchange (ETDEWEB)

    Darma, Susan; Krause, Baerbel; Doyle, Stephen; Mangold, Stefan; Baumbach, Tilo [ISS, Karlsruher Institut fuer Technologie (Germany); Ulrich, Sven; Stueber, Michael [IAM-AWP, Karlsruher Institut fuer Technologie (Germany)

    2012-07-01

    Multi-element hard coating materials such as V-Al-C-N are of great interest for many technological applications. Their mechanical properties depend on the composition and microstructure of the coating. In order to determine the optimum composition and deposition conditions of these complex materials, many samples are required. One powerful tool for reducing the number of experiments is based on the so-called combinatorial approach for thin film deposition: many different thin film samples can be realized simultaneously, exploiting the deposition gradient resulting from codeposition of several materials. We will present an X-ray diffraction study of the influence of the deposition geometry on the microstructure of V-Al-C-N coatings. The films were deposited by reactive RF magnetron sputtering from a segmented target composed of AlN and VC. Synchrotron radiation measurements where performed at the beamline PDIFF at ANKA. Significant texture changes were observed which can be attributed to the deposition geometry, as verified by calculations of the flux distribution. We conclude that codeposition can accelerate significantly the screening of new materials, under the condition that the desired property is not significantly influenced by the microstructural changes due to the deposition geometry.

  3. Deformed glacial deposits of Passamaquoddy Bay area, New Brunswick

    International Nuclear Information System (INIS)

    Kumarapeli, S.

    1990-03-01

    The New Brunswick-Maine border area, centred around Passamaquoddy Bay, is characterized by a distinctly higher level of seismic activity compared with the very low level background activity of the region. In this same general area, post-glacial deformation including faulting, has been observed in glaciofluvial and ice contact deposits and the possibility that these structures may in some way related to neotectonic movements in the area has been suggested. A study was undertaken to document these structures and to investigate their origin. The studies show that structures related to collapse of sediments due to melting of buried ice masses are the most prominent post-depositional structures in the glacial sediments. A second group of structures includes failure phenomena such as slumping. These require the action of a mechanism leading to reduction of sediment strength which could be achieved by seismic shaking. However, such failure phenomena could also be brought about by non-seismic processes, thus a unique interpretation of the origin of these structures is difficult, if not impossible. Since seismic shaking is the most effective, regionally extensive trigger of a broad group of failure phenomena in soft sediments, the related structures are usually spread over a large area, but are restricted to a very short time gap. Although the establishment of such space and time relationships may be feasible, for example in extensive lake deposits, it is difficult to do so in patchy laterally variable deposits such as the glacial deposits in Passamaquoddy Bay area

  4. Vertically aligned carbon nanotube growth by pulsed laser deposition and thermal chemical vapor deposition methods

    International Nuclear Information System (INIS)

    Sohn, Jung Inn; Nam, Chunghee; Lee, Seonghoon

    2002-01-01

    We have grown vertically aligned carbon nanotubes on the various substrates such as a planar p-type Si(1 0 0) wafer, porous Si wafer, SiO 2 , Si 3 N 4 , Al 2 O 3 , and Cr by thermal chemical vapor deposition (CVD) at 800 deg.C, using C 2 H 2 gas as a carbon source and Fe catalyst films deposited by a pulsed laser on the substrates. The Fe films were deposited for 5 min by pulsed laser deposition (PLD). The advantage of Fe deposition by PLD over other deposition methods lies in the superior adhesion of Fe to a Si substrate due to high kinetic energies of the generated Fe species. Scanning electron microscopy (SEM) images show that vertically well-aligned carbon nanotubes are grown on Fe nanoparticles formed from the thermal annealing of the Fe film deposited by PLD on the various substrates. Atomic force microscopy (AFM) images show that the Fe film annealed at 800 deg.C is broken to Fe nanoparticles of 10-50 nm in size. We show that the appropriate density of Fe nanoparticles formed from the thermal annealing of the film deposited by PLD is crucial in growing vertically aligned carbon nanotubes. Using a PLD and a lift-off method, we developed the selective growth of carbon nanotubes on a patterned Fe-coated Si substrate

  5. Fluorine and boron co-doped diamond-like carbon films deposited by pulsed glow discharge plasma immersion ion processing

    CERN Document Server

    He, X M; Peters, A M; Taylor, B; Nastasi, M

    2002-01-01

    Fluorine (F) and boron (B) co-doped diamond-like carbon (FB-DLC) films were prepared on different substrates by the plasma immersion ion processing (PIIP) technique. A pulse glow discharge plasma was used for the PIIP deposition and was produced at a pressure of 1.33 Pa from acetylene (C sub 2 H sub 2), diborane (B sub 2 H sub 6), and hexafluoroethane (C sub 2 F sub 6) gas. Films of FB-DLC were deposited with different chemical compositions by varying the flow ratios of the C sub 2 H sub 2 , B sub 2 H sub 6 , and C sub 2 F sub 6 source gases. The incorporation of B sub 2 H sub 6 and C sub 2 F sub 6 into PIIP deposited DLC resulted in the formation of F-C and B-C hybridized bonding structures. The levels of the F and B concentrations effected the chemical bonding and the physical properties as was evident from the changes observed in density, hardness, stress, friction coefficient, and contact angle of water on films. Compared to B-doped or F-doped DLC films, the F and B co-doping of DLC during PIIP deposition...

  6. Thermal barrier coatings of rare earth materials deposited by electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhenhua [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); He Limin, E-mail: he_limin@yahoo.co [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Chen Xiaolong; Zhao Yu [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Cao Xueqiang, E-mail: xcao@ciac.jl.c [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2010-10-15

    Thermal barrier coatings (TBCs) have very important applications in gas turbines for higher thermal efficiency and protection of components at high temperature. TBCs of rare earth materials such as lanthanum zirconate (La{sub 2}Zr{sub 2}O{sub 7}, LZ), lanthanum cerate (La{sub 2}Ce{sub 2}O{sub 7}, LC), lanthanum cerium zirconate (La{sub 2}(Zr{sub 0.7}Ce{sub 0.3}){sub 2}O{sub 7}, LZ7C3) were prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, cross-sectional morphology and cyclic oxidation behavior of these coatings were studied. These coatings have partially deviated from their original compositions due to the different evaporation rates of oxides, and the deviation could be reduced by properly controlling the deposition condition. A double ceramic layer-thermal barrier coatings (DCL-TBCs) of LZ7C3 and LC could also be deposited with a single LZ7C3 ingot by properly controlling the deposition energy. LaAlO{sub 3} is formed due to the chemical reaction between LC and Al{sub 2}O{sub 3} in the thermally grown oxide (TGO) layer. The failure of DCL-TBCs is a result of the sintering-induced of LZ7C3 coating and the chemical incompatibility of LC and TGO. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL-TBCs are an important development direction of TBCs.

  7. On the Internal Structure of Mobile Barchan Sand Dunes due to Granular Processes

    Science.gov (United States)

    Vriend, N. M.; Arran, M.; Louge, M. Y.; Hay, A. G.; Valance, A.

    2017-12-01

    In this work, we visualize the internal structure of mobile barchan desert dunes at the avalanche scale. We reveal an intriguing history of dune building using a novel combination of local sand sampling and advanced geophysical techniques resulting in high resolution measurements of individual avalanche events. Due to progressive rebuilding, granular avalanching, erosional and depositional processes, these marching barchan dunes are reworked every few years and a characteristic zebra-pattern (figure 1a), orientated parallel to the slipface at the angle of repose, appears at regular intervals. We present scientific data on the structure obtained from several mobile barchan dunes of different sizes during recent desert field campaigns (2014, 2015, 2017) in a mobile barchan dune field in Qatar (25.01°N, 51.34°E in the AlWakrah municipality). The site has been equipped with a weather station and has been regularly visited by a multidisciplinary research team in recent years (e.g. [1]). By applying high-frequency (1200 MHz) ground penetrating radar (GPR) transects across the midline (figure 1b) we map the continuous evolution of this cross-bedding at high resolution deep within the dune. The GPR reveals a slope reduction of the slipface near the base of the dune; evidence of irregular wind reversals; and the presence of a harder aeolian cap around the crest and extending to the brink. The data is supplemented with granulometry from layers stabilized by dyed water injection and uncovered by excavating vertical walls perpendicular to old buried avalanches. We attribute visible differences in water penetration between adjacent layers to fine particle segregation processes in granular avalanches. This work was made possible by the support of NPRP grant 6-059-2-023 from the Qatar National Research Fund to MYL and AGH, and a Royal Society Dorothy Hodgkin Research Fellowship to NMV. We thank Jean-Luc Métayer for performing detailed particle size distribution measurements

  8. Simulation of erosion and deposition processes of many-component surface layers in fusion devices; Simulation von Erosion- und Depositionsprozessen mehrkomponentiger Oberflaechenschichten in Fusionsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Droste, S.

    2007-02-15

    The present choice of first wall materials in ITER will unavoidably lead to the formation of mixed carbon, tungsten and beryllium layers. Predictive modelling of erosion processes, impurity transport and deposition processes is important. For this the 3D Monte-Carlo code ERO can be used. In this thesis ERO has been coupled to the existing Monte-Carlo code SDTrimSP to describe material mixing processes in wall components correctly. SDTrimSP describes the surface by calculating the transport of ions in solids. It keeps track of the depth dependent material concentration caused by the implantation of projectiles in the solid. The calculation of movements of the recoil atoms within the solid gives reflection coefficients and sputtering yields. Since SDTrimSP does not consider chemical processes a new method has been developed to implement chemical erosion of carbon by the impact of hydrogen projectiles. The new code ERO-SDTrimSP was compared to TEXTOR experiments which were carried out to study the formation of mixed surface layers. In these experiments methane CH4 was injected through drillings in graphite and tungsten spherical limiters into the plasma. A pronounced substrate dependence was observed. The deposition efficiency, i.e. the ratio of the locally deposited to the injected amount of carbon, was 4% for graphite and 0.3% for tungsten. The deposition-dominated area on the graphite limiter covers a five times larger area than on the tungsten limiter. Modelling of this experiment with ERO-SDTrimSP also showed a clear substrate dependence with 2% deposition efficiency for graphite and less than 0.5% for tungsten. An important result of the comparison between experiment and simulation was that the effective sticking of hydrocarbon radicals hitting the surface must be negligible. Furthermore, it was shown that local re-deposited carbon layers are 10 times more effectively eroded than ordinary graphite. Simulation of the impurity transport in the plasma was checked

  9. Deposition and high temperature corrosion in a 10 MW straw

    DEFF Research Database (Denmark)

    Michelsen, Hanne Philbert; Frandsen, Flemming; Dam-Johansen, Kim

    1998-01-01

    Deposition and corrosion measurements were conducted at a 10 MW wheat straw fired stoker boiler used for combined power and heat production. The plant experiences major problems with deposits on the heat transfer surfaces, and test probes have shown enhanced corrosion due to selective corrosion...... for metal temperatures above 520 C. Deposition measurements carried out at a position equal to the secondary superheater showed deposits rich in potassium and chlorine and to a lesser extent in silicon, calcium, and sulfur. Potassium and chlorine make up 40-80 wt% of the deposits. Mechanisms of deposit...

  10. Nature of the pulsed laser process for the deposition of high T/sub c/ superconducting thin films

    International Nuclear Information System (INIS)

    Venkatesan, T.; Wu, X.D.; Inam, A.

    1988-01-01

    The pulsed laser thin-film deposition process can enable preparation of thin films of complex composition with good control over the film stoichiometry. The film compositions are similar to that of the target pellet and as a consequence this technique appears to be an ideal method for preparing high T/sub c/ thin films on a variety of substrates.The factors which contribute to this beneficial phenomenon have been explored by a laser ionization mass spectrometry (LIMS) and a post ablation ionization (PAI) neutral velocity analysis technique in order to determine the mass and velocities of the laser ejected material. In addition, x-ray absorption measurements on films deposited onto substrates at room temperature were performed in order to identify the presence of short-range crystalline order in the films. Both of these studies rule out the ejection of stoichiometric clusters of material from the pellet during the laser ablation/deposition process. Instead, binary and ternary suboxides are emitted from the target pellet. These suboxides most likely have unit sticking coefficient to the substrate which could contribute to the preservation of the film stoichiometry. The velocity distribution of several neutral species (e.g., BaO) indicates that particles have energies of several eV. Thus the effective temperatures of the emitted species are ∼15 x 10 3 K, and these energetic particles may facilitate growth of the crystalline films at low substrate temperatures

  11. Acidic deposition and its effects on forest productivity: a review of the present state of knowledge, research activities, and information needs

    Energy Technology Data Exchange (ETDEWEB)

    Pinkerton, J.E.

    1981-01-01

    The present state of knowledge with regard to acid deposition is reviewed. Sources include the literature and direct contact with persons responsible for carrying out all completed, ongoing, and planned research activities, national and international, related to acidic deposition and its effects, with emphasis on forest productivity. In addition, a list of information needs in seven areas was developed, these include: a characterization of forest soils to define their sensitivity to acidic deposition; effects on forest soil chemical and biological processes; development of improved dry deposition measurement methods; changes in precipitation composition due to forest canopies; more extensive monitoring of acidic deposition in industry owned forest lands; expansion of long-term greenhouse and controlled field experiments; and the relationship of acidic deposition and intensive forestry management practices. 85 references. (MDF)

  12. Effects of deposition conditions on the properties of pyrolytic carbon deposited in a fluidized bed

    International Nuclear Information System (INIS)

    Lowden, Richard Andrew; Hunn, John D.; Nunn, Stephen D.; Kercher, Andrew K.; Price, Jeffery R.; Jellison, Gerald Earle Jr.

    2005-01-01

    The high-density, isotropic pyrolytic carbon layer beneath the silicon carbide (IPyC) plays a key role in the irradiation performance of coated particle fuel. The IPyC layer protects the kernel from reactions with chlorine during deposition of the SiC layer, provides structural support for the SiC layer, and protects the SiC from fission products and carbon monoxide. The process conditions used by the Germans to deposit the IPyC coating produced a highly isotropic, but somewhat permeable IPyC coating. The permeability of the IPyC coating was acceptable for use with the dense German UO 2 kernels, but may not be suitable when coating UCO kernels. The UCO kernels are typically more porous and thus have a larger surface area than UO 2 kernels. The lower density and the higher surface area of UCO kernels could make them more susceptible to attack by HCl gas during the silicon carbide (SiC) coating process, which could result in heavy metal dispersion into the buffer and IPyC coatings and a higher level of as-manufactured SiC defects. The relationship between IPyC deposition conditions, permeability, and anisotropy must be understood and the appropriate combination of anisotropy and permeability for particle fuel containing UCO kernels selected. A reference set of processing conditions have been determined from review of historical information and results of earlier coating experiments employing 350 and 500 (micro)m UO 2 kernels. It was decided that a limited study would be conducted, in which only coating gas fraction (CGF) and temperature would be varied. Coatings would be deposited at different rates and with a range of microstructures. Thickness, density, porosity and anisotropy would be measured and permeability evaluated using a chlorine leach test. The results would be used to select the best IPyC coating conditions for use with the available natural enrichment uranium carbide/uranium oxide (NUCO) kernels. The response plots from the investigation of the

  13. Atmospheric deposition of nitrogen at five subtropical forested sites in South China

    International Nuclear Information System (INIS)

    Chen, Xi Yun; Mulder, Jan

    2007-01-01

    Elevated concentrations of reactive nitrogen (N) in precipitation have been reported for many cities in China. Due to increased use of fossil fuels and expansion in agriculture, further increases in deposition of ammonia (NH x ) and reactive N oxides (NO y ) are predicted. Increased deposition of reactive N is likely to affect N dynamics and N runoff in forest ecosystems. Yet, in China little work has been done to quantify the levels of atmospheric N deposition in such systems. Here, we assess the deposition of inorganic N (ammonium, NH 4 + and nitrate, NO 3 - ) for five subtropical forest ecosystems in remote and urban areas of South China. Annual volume-weighted concentrations in bulk precipitation range from 0.18 to 1.55 mg NH 4 + -N L - 1 and from 0.12 to 0.74 mg NO 3 - -N L - 1 . These values are large and several times greater than those reported for remote sites of the world. The fluxes of total inorganic N (TIN) in wet-only deposition range from 0.8 to 2.3 g N m - 2 yr - 1 , with NH 4 + -N contributing 54% to 77%. Both the tree canopy and the ground vegetation layer are important in determining the net N flux reaching the forest floor, but the net effect varies from site to site. At TieShanPing (TSP), close to Chongqing city, and at CaiJiaTang (CJT), near Shaoshan (Hunan province), the canopy represents a net source of N, probably due to dry deposition. At the other three sites (LiuChongGuan (LCG), LeiGongShan (LGS), both in Guizhou province, and LiuXiHe (LXH) in Guangdong), a net loss of reactive N from precipitation water occurs in the canopy, probably due to uptake processes. The total annual atmospheric TIN load is estimated to range from at least 0.8 g N m - 2 yr - 1 to 4.0 g N m - 2 yr - 1 , with a considerable contribution from dry deposition. Concentrations and fluxes of inorganic N in tree canopy throughfall are greater than those in North America. Also the contribution of NH 4 + -N to TIN fluxes in throughfall (40% to 70%) is greater than in North

  14. Cortical T2 signal shortening in amyotrophic lateral sclerosis is not due to iron deposits

    Energy Technology Data Exchange (ETDEWEB)

    Hecht, M.J.; Neundoerfer, B. [University of Erlangen-Nurenberg, Department of Neurology, Erlangen (Germany); Fellner, C.; Fellner, F.A. [University of Erlangen-Nurenberg, Institute of Diagnostic Radiology, Erlangen (Germany); Landes-Nervenklinik Wagner-Jauregg, Institute of Radiology, Linz (Austria); Schmid, A. [University of Erlangen-Nurenberg, Institute of Diagnostic Radiology, Erlangen (Germany)

    2005-11-01

    Signal shortening of the motor cortex in T2-weighted MR images is a frequent finding in patients with amyotrophic lateral sclerosis (ALS). The cause of signal shortening in ALS is unknown, although iron deposits have been suggested. To test this hypothesis, we acquired T2*-weighted gradient-echo (GRE) MR images in addition to T2-weighted turbo spin-echo in 69 patients with ALS. Signal shortening in T2-weighted images was found in 31 patients. In T2*-weighted GRE images, only three patients had signal shortening. One patient with additional bifrontal haemorrhage had frontal but no motor cortex signal shortening. Iron deposits do not cause cortical signal shortening in patients with ALS predominantly. Other factors are presumably more important in the generation of cortical T2 shortening in ALS. (orig.)

  15. Cortical T2 signal shortening in amyotrophic lateral sclerosis is not due to iron deposits

    International Nuclear Information System (INIS)

    Hecht, M.J.; Neundoerfer, B.; Fellner, C.; Fellner, F.A.; Schmid, A.

    2005-01-01

    Signal shortening of the motor cortex in T2-weighted MR images is a frequent finding in patients with amyotrophic lateral sclerosis (ALS). The cause of signal shortening in ALS is unknown, although iron deposits have been suggested. To test this hypothesis, we acquired T2*-weighted gradient-echo (GRE) MR images in addition to T2-weighted turbo spin-echo in 69 patients with ALS. Signal shortening in T2-weighted images was found in 31 patients. In T2*-weighted GRE images, only three patients had signal shortening. One patient with additional bifrontal haemorrhage had frontal but no motor cortex signal shortening. Iron deposits do not cause cortical signal shortening in patients with ALS predominantly. Other factors are presumably more important in the generation of cortical T2 shortening in ALS. (orig.)

  16. Quantitative analysis of precipitation over Fukushima to understand the wet deposition process in March 2011

    Science.gov (United States)

    Yatagai, A.; Onda, Y.; Watanabe, A.

    2012-04-01

    The Great East Japan Earthquake caused a severe accident at the Fukushima-Daiichi nuclear power plant (NPP), leading to the emission of large amounts of radioactive pollutants into the environment. The transport and diffusion of these radioactive pollutants in the atmosphere caused a disaster for residents in and around Fukushima. Studies have sought to understand the transport, diffusion, and deposition process, and to understand the movement of radioactive pollutants through the soil, vegetation, rivers, and groundwater. However, a detailed simulation and understanding of the distribution of radioactive compounds depend on a simulation of precipitation and on the information on the timing of the emission of these radioactive pollutants from the NPP. Past nuclear expansion studies have demonstrated the importance of wet deposition in distributing pollutants. Hence, this study examined the quantitative precipitation pattern in March 2011 using rain-gauge observations and X-band radar data from Fukushima University. We used the AMeDAS rain-gauge network data of 1) the Japan Meteorological Agency (1273 stations in Japan) and 2) the Water Information System (47 stations in Fukushima prefecture) and 3) the rain-gauge data of the Environmental Information Network of NTT Docomo (30 stations in Fukushima) to construct 0.05-degree mesh data using the same method used to create the APHRODITE daily grid precipitation data (Yatagai et al., 2009). Since some AMeDAS data for the coastal region were lost due to the earthquake, the complementary network of 2) and 3) yielded better precipitation estimates. The data clarified that snowfall was observed on the night of Mar 15 into the morning of Mar 16 throughout Fukushima prefecture. This had an important effect on the radioactive contamination pattern in Fukushima prefecture. The precipitation pattern itself does not show one-on-one correspondence with the contamination pattern. While the pollutants transported northeast of the

  17. Solid Organic Deposition During Gas Injection Studies

    DEFF Research Database (Denmark)

    Dandekar, Abhijit Y.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    2000-01-01

    Recently a series of first contact miscibility (swelling) experiments have been performed on undersaturated light and heavy oils using LPG rich and methane rich injection gases, in which solid organic deposition was observed. A compositional gradient in the oils during the gas injection process....... The asphaltene content of the different oil samples were determined by the TP 143 method. The standard asphaltenes and the solid organic deposit recovered from the swelling tests were analyzed using FTIR, HPLC-SEC and H-1 NMR. The aim of these analyses is to reveal the molecular nature of the deposits formed...... during the gas injection process in comparison with the standard asphaltenes in order to understand the mechanisms involved in asphaltene deposition....

  18. Energy and momentum deposition to plasmas due to the lower hybrid wave by a finite source

    International Nuclear Information System (INIS)

    Nakajima, Noriyoshi; Abe, Hirotada; Itatani, Ryohei.

    1981-10-01

    Heating and current generation due to the lower hybrid wave are studied using the particle simulation. In contrast with previous work, where only the single mode is treated, main interests of this work are focused on the physical problems on a propagation cone consisting of many Fourier-expanded modes. It is found that the trajectory of the propagation cone is well described up to the lower hybrid resonance layer using both cold plasma approximation and the WKB method. An ion cross-field drift due to the ponderomotive force is observed. It is a main discovery that the modes in the higher side of the spectrum of the antenna play a key role for creation of the ion high energy tail. This process cannot be explained by the linear theory and is called the cascade process judging from the time variation of the damping of each mode. The particle model is significantly improved using the elongated grid and the quadric spatial interpolation. Many applications of this model to the simulations on other problems are expected to be very fruitful in the research of the plasma physics and nuclear fusion. (author)

  19. Microbial weathering processes after release of heavy metals and arsenic from fluvial tailing deposits; Mikrobielle Verwitterungsprozesse bei der Freisetzung von Schwermetallen und Arsen aus fluvialen Tailingablagerungen

    Energy Technology Data Exchange (ETDEWEB)

    Willscher, S. [Technische Univ. Dresden (Germany). Fak. fuer Forst, Geo und Hydrowissenschaften, Inst. fuer Abfallwirtschaft und Altlasten

    2006-07-01

    Microbial processes play an important role in global metal cycles. The microbial weathering of mineral surfaces, including deposited anthropogenic mineral remainders, is a natural occurring process, taking place on uncovered dump surfaces as well as in deeper zones of dumps. Such weathering processes also occur in metal contaminated soils and sediments. In this work, a sulfidic fluvial tailing sediment was investigated for its acidity and salinity generating potential and the subsequent mobilisation of heavy metals, generated by biogeochemical processes. The long-term risks of such a deposit were evaluated. Unstabilised deposits of such materials can generate a considerable contamination of the surrounding ground and surface water. It could be shown in the experiments that in acid generating dumps and tailing materials besides the well known acidophilic autotrophs also acidotolerant heterotrophic microorganisms play a role in the mobilisation of metals. (orig.)

  20. Exploitation by in-situ leaching of an uranium deposit in Kazakhstan

    International Nuclear Information System (INIS)

    Belieres, M.

    2006-01-01

    ISL is a process allowing recovery of valuable metal from a low grade deposit without mining operation. Geological and physical conditions are very strict. The reagent used may be alkaline (mixture of alkaline carbonate and bicarbonate) or acid (sulfuric acid).The paper describes such an operation in Kazakhstan, pointing out the preliminary studies, pilot operations and industrial operation starting up and explains the specific difficulties due to the environment and the remoteness of the mine site. (author)

  1. Fabrication of a miniature diamond grinding tool using a hybrid process of micro-EDM and co-deposition

    International Nuclear Information System (INIS)

    Chen, Shun-Tong; Lai, Yun-Cheng; Liu, Ching-Chang

    2008-01-01

    A novel miniature diamond grinding tool usable for the precise micro-grinding of miniature parts is presented. A hybrid process that combines 'micro-EDM' with 'precision co-deposition' is proposed. The metal substrate is micro-EDMed to a 50 µm diameter and micro diamonds with 0–2 µm grains are 'electroformed' on the substrate surface, producing a miniature multilayered grinding tool. Nickel and diamond act as binders and cutters, respectively. A partition plate with an array of drilled holes is designed to ensure good convection in the electroforming solution. The dispersion of diamond grains and displacement of nickel ions are noticeably improved. A miniature funnel mould enables the diamond grains to converge towards the cathode to increase their deposition probability on the substrate, thereby improving their distribution on the substrate surface. A micro ZrO 2 ceramic ferrule is finely ground by the developed grinding tool and then yields a surface roughness of R a = 0.085 µm. The proposed approach is applied during the final machining process

  2. CTS and CZTS for solar cells made by pulsed laser deposition and pulsed electron deposition

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt

    This thesis concerns the deposition of thin films for solar cells using pulsed laser deposition (PLD) and pulsed electron deposition (PED). The aim was to deposit copper tin sulfide (CTS) and zinc sulfide (ZnS) by pulsed laser deposition to learn about these materials in relation to copper zinc tin...... time. We compared the results of CZTS deposition by PLD at DTU in Denmark to CZTS made by PED at IMEM-CNR, where CIGS solar cells have successfully been fabricated at very low processing temperatures. The main results of this work were as follows: Monoclinic-phase CTS films were made by pulsed laser...... deposition followed by high temperature annealing. The films were used to understand the double band gap that we and other groups observed in the material. The Cu-content of the CTS films varied depending on the laser fluence (the laser energy per pulse and per area). The material transfer from...

  3. Observation- and model-based estimates of particulate dry nitrogen deposition to the oceans

    Directory of Open Access Journals (Sweden)

    A. R. Baker

    2017-07-01

    Full Text Available Anthropogenic nitrogen (N emissions to the atmosphere have increased significantly the deposition of nitrate (NO3− and ammonium (NH4+ to the surface waters of the open ocean, with potential impacts on marine productivity and the global carbon cycle. Global-scale understanding of the impacts of N deposition to the oceans is reliant on our ability to produce and validate models of nitrogen emission, atmospheric chemistry, transport and deposition. In this work,  ∼  2900 observations of aerosol NO3− and NH4+ concentrations, acquired from sampling aboard ships in the period 1995–2012, are used to assess the performance of modelled N concentration and deposition fields over the remote ocean. Three ocean regions (the eastern tropical North Atlantic, the northern Indian Ocean and northwest Pacific were selected, in which the density and distribution of observational data were considered sufficient to provide effective comparison to model products. All of these study regions are affected by transport and deposition of mineral dust, which alters the deposition of N, due to uptake of nitrogen oxides (NOx on mineral surfaces. Assessment of the impacts of atmospheric N deposition on the ocean requires atmospheric chemical transport models to report deposition fluxes; however, these fluxes cannot be measured over the ocean. Modelling studies such as the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP, which only report deposition flux, are therefore very difficult to validate for dry deposition. Here, the available observational data were averaged over a 5° × 5° grid and compared to ACCMIP dry deposition fluxes (ModDep of oxidised N (NOy and reduced N (NHx and to the following parameters from the Tracer Model 4 of the Environmental Chemical Processes Laboratory (TM4: ModDep for NOy, NHx and particulate NO3− and NH4+, and surface-level particulate NO3− and NH4+ concentrations. As a model ensemble, ACCMIP can be

  4. Geochronology of the Thompson Creek Mo Deposit: Evidence for the Formation of Arc-related Mo Deposits

    Science.gov (United States)

    Lawrence, C. D.; Coleman, D. S.; Stein, H. J.

    2016-12-01

    The Thompson Creek Mo deposit in central ID, has been categorized as an arc-related Mo deposit due to the location, grade of Mo, and relative lack of enrichments in F, Rb, and Nb, compared to the Climax-type Mo deposits. Geochronology from this arc-related deposit provides an opportunity to compare and contrast magmatism, and mineralization to that in Climax-type deposits. Distinct pulses of magmatism were required to form the Thompson Creek Mo deposit, which is consistent with recent geochronology from Climax-type deposits. Molybdenite Re-Os geochronology from five veins requires at least three pulses of magmatism and mineralization between 89.39 +/- 0.37 and 88.47 +/- 0.16 Ma. Zircon U-Pb ages from these mineralized samples overlap with molybdenite mineralization, but show a much wider range (91.01 +/- 0.37 to 87.27 +/- 0.69). Previous work from Climax-type Mo deposits suggest a correlation between a super eruption, and the subsequent rapid (<1 Ma) onset, and completion of Mo mineralizing intrusions. The longer life (3-4 Ma) for the Thompson Creek Mo deposit suggests that the mineralizing intrusions for arc-related Mo deposits may not need to have as high [Mo] as the Climax-type deposits. This study also finds a shift in the source of magmatism from the pre- to syn-mineralizing intrusions. Zircons from pre-mineralizing intrusions have much higher (15-60 pg) concentrations of radiogenic Pb than zircons from mineralized intrusions, which all have less than 15 pg, though whole rock [U] are similar.

  5. Substrate Effect on Plasma Clean Efficiency in Plasma Enhanced Chemical Vapor Deposition System

    Directory of Open Access Journals (Sweden)

    Shiu-Ko JangJian

    2007-01-01

    Full Text Available The plasma clean in a plasma-enhanced chemical vapor deposition (PECVD system plays an important role to ensure the same chamber condition after numerous film depositions. The periodic and applicable plasma clean in deposition chamber also increases wafer yield due to less defect produced during the deposition process. In this study, the plasma clean rate (PCR of silicon oxide is investigated after the silicon nitride deposited on Cu and silicon oxide substrates by remote plasma system (RPS, respectively. The experimental results show that the PCR drastically decreases with Cu substrate compared to that with silicon oxide substrate after numerous silicon nitride depositions. To understand the substrate effect on PCR, the surface element analysis and bonding configuration are executed by X-ray photoelectron spectroscopy (XPS. The high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS is used to analyze microelement of metal ions on the surface of shower head in the PECVD chamber. According to Cu substrate, the results show that micro Cu ion and the CuOx bonding can be detected on the surface of shower head. The Cu ion contamination might grab the fluorine radicals produced by NF3 ddissociation in the RPS and that induces the drastic decrease on PCR.

  6. Self-Ordering and Complexity in Epizonal Mineral Deposits

    Science.gov (United States)

    Henley, Richard W.; Berger, Byron R.

    Epizonal base and precious metal deposits makeup a range of familiar deposit styles including porphyry copper-gold, epithermal veins and stockworks, carbonate-replacement deposits, and polymetallic volcanic rock-hosted (VHMS) deposits. They occur along convergent plate margins and are invariably associated directly with active faults and volcanism. They are complex in form, variable in their characteristics at all scales, and highly localized in the earth's crust. More than a century of detailed research has provided an extensive base of observational data characterizing these deposits, from their regional setting to the fluid and isotope chemistry of mineral deposition. This has led to a broad understanding of the large-scale hydrothermal systems within which they form. Low salinity vapor, released by magma crystallization and dispersed into vigorously convecting groundwater systems, is recognized as a principal source of metals and the gases that control redox conditions within systems. The temperature and pressure of the ambient fluid anywhere within these systems is close to its vapor-liquid phase boundary, and mineral deposition is a consequence of short timescale perturbations generated by localized release of crustal stress. However, a review of occurrence data raises questions about ore formation that are not addressed by traditional genetic models. For example, what are the origins of banding in epithermal veins, and what controls the frequency of oscillatory lamination? What controls where the phenomenon of mineralization occurs, and why are some porphyry deposits, for example, so much larger than others? The distinctive, self-organized characteristics of epizonal deposits are shown to be the result of repetitive coupling of fracture dilation consequent on brittle failure, phase separation ("boiling"), and heat transfer between fluid and host rock. Process coupling substantially increases solute concentrations and triggers fast, far

  7. Acid-deposition research program. Volume 2. Effects of acid-forming emissions on soil microorganisms and microbially-mediated processes

    Energy Technology Data Exchange (ETDEWEB)

    Visser, S.; Danielson, R.M.; Parr, J.F.

    1987-02-01

    The interactions of soil physical, chemical, and biological processes are ultimately expressed in a soil's fertility and its capacity for plant production. Consequently, much of the research conducted to date regarding the impact of acid-forming pollutants on soil properties has been geared towards possible effects on plant productivity. This trend continues in this paper where the effects of acidic deposition on microbial communities are reviewed in relation to potential impact on plant growth. The objectives of the review are to discuss: (1) The effects of acid-forming emissions (primarily S-containing pollutants) on microbial community structure with emphasis on qualitative and quantitative aspects; (2) The effects of acidic deposition on microbially mediated processes (i.e., community functions); (3) Acidification effects of pollutants on symbiotic and disease-causing microorganisms. The symbionts discussed include ectomycorrhizal fungi, vesicular-arbuscular mycorrhizal fungi, and N/sub 2/-fixing bacteria, particularly Rhizobium, while the disease-causing microorganisms will include those responsible for foliage, stem, and root diseases.

  8. Fog deposition to the Atacama desert

    Science.gov (United States)

    Westbeld, A.; Klemm, O.; Griessbaum, F.; Sträter, E.; Larrain, H.; Osses, P.; Cereceda, P.

    2010-07-01

    In the Atacama Desert, one of the driest places on earth, fog deposition plays an important role for the water balance and for the survival of vulnerable ecosystems. The eddy covariance method, previously applied for the quantification of fog deposition to forests in various parts of the world, was used for the first time to measure deposition of fog water to a desert. We estimated the amount of water available for the ecosystem by deposition and determined the relevant processes driving fog deposition. This is especially important for the species Tillandsia landbecki living in coastal Atacama at the limit of plant existence with fog and dew being the only sources of liquid water. Between 31 July and 19 August, 2008, measurements were realized in a 31 ha large Tillandsia carpet at Cerro Guanaco, located 15 km south of Iquique, northern Chile. Several data quality assurance procedures were applied. For the values in compliance with the applied criteria, the mean total deposition per hour was determined (0.04 L per m2) for foggy periods. This number was applied to estimate the amount of water deposited during the measuring period, during the entire month of August 2008, and throughout a whole year. For August 2008, a frequency of fog of 16 %, as established during the measuring period, was assumed. The frequency for a whole year was estimated from the differences of the collected amount of water obtained with standard fog collectors installed at Cerro Guanaco in an earlier study. Calculations resulted in an amount of 2.5 L per m2 of deposited fog water for the measuring period. During the entire August, 4.4 L per m2 have likely been available, and for a whole year, a total of 25 L per m2 was estimated to have reached the surface. Inaccuracies could have been caused by the low amount of data applied, and by a possible underestimation of the deposition due to additional formation of radiation fog during the fog events. Three days were used for further analysis because

  9. Effect of post-deposition implantation and annealing on the properties of PECVD deposited silicon nitride films

    International Nuclear Information System (INIS)

    Shams, Q.A.

    1988-01-01

    Recently it has been shown that memory-quality silicon nitride can be deposited using plasma enhanced chemical vapor deposition (PECVD). Nitrogen implantation and post-deposition annealing resulted in improved memory properties of MNOS devices. The primary objective of the work described here is the continuation of the above work. Silicon nitride films were deposited using argon as the carrier gas and evaluated in terms of memory performance as the charge-trapping layer in the metal-nitride-oxide-silicon (MNOS) capacitor structure. The bonding structure of PECVD silicon nitride was modified by annealing in different ambients at temperatures higher than the deposition temperature. Post-deposition ion implantation was used to introduce argon into the films in an attempt to influence the transfer, trapping, and emission of charge during write/erase exercising of the MNOS devices. Results show that the memory performance of PECVD silicon nitride is sensitive to the deposition parameters and post-deposition processing

  10. A pressure tuned stop-flow atomic layer deposition process for MoS2 on high porous nanostructure and fabrication of TiO2/MoS2 core/shell inverse opal structure

    Science.gov (United States)

    Li, Xianglin; Puttaswamy, Manjunath; Wang, Zhiwei; Kei Tan, Chiew; Grimsdale, Andrew C.; Kherani, Nazir P.; Tok, Alfred Iing Yoong

    2017-11-01

    MoS2 thin films are obtained by atomic layer deposition (ALD) in the temperature range of 120-150 °C using Mo(CO)6 and dimethyl disulfide (DMDS) as precursors. A pressure tuned stop-flow ALD process facilitates the precursor adsorption and enables the deposition of MoS2 on high porous three dimensional (3D) nanostructures. As a demonstration, a TiO2/MoS2 core/shell inverse opal (TiO2/MoS2-IO) structure has been fabricated through ALD of TiO2 and MoS2 on a self-assembled multilayer polystyrene (PS) structure template. Due to the self-limiting surface reaction mechanism of ALD and the utilization of pressure tuned stop-flow ALD processes, the as fabricated TiO2/MoS2-IO structure has a high uniformity, reflected by FESEM and FIB-SEM characterization. A crystallized TiO2/MoS2-IO structure can be obtained through a post annealing process. As a 3D photonic crystal, the TiO2/MoS2-IO exhibits obvious stopband reflecting peaks, which can be adjusted through changing the opal diameters as well as the thickness of MoS2 layer.

  11. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Trkula, M.

    1996-01-01

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  12. Radionuclide deposition control

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

  13. Incidence and outcome of patients starting renal replacement therapy for end-stage renal disease due to multiple myeloma or light-chain deposit disease: an ERA-EDTA Registry study

    DEFF Research Database (Denmark)

    Tsakiris, D.J.; Stel, V.S.; Finne, P.

    2010-01-01

    Background. Information on demographics and survival of patients starting renal replacement therapy (RRT) for end-stage renal disease (ESRD) due to multiple myeloma (MM) or light-chain deposit disease (LCDD) is scarce. The aim of this study was to describe the incidence, characteristics, causes...... causes (non-MM) was observed overtime. Patient survival on RRT was examined, unadjusted and adjusted for age and gender. Results. Of the 159 637 patients on RRT, 2453 (1.54%) had MM or LCDD. The incidence of RRT for ESRD due to MM or LCDD, adjusted for age and gender, increased from 0.70 pmp in 1986...

  14. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Strandstroem, Kjell; Mueller, Christian; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Biskopsgatan 8, FI-20500 Aabo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling is since long considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. (author)

  15. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Kjell Strandstroem; Christian Muellera; Mikko Hupa [Abo Akademi Process Chemistry Centre, Abo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling has long been considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. 12 refs., 10 figs.

  16. Towards a genetic classification of uranium deposits

    International Nuclear Information System (INIS)

    Cuney, M.

    2009-01-01

    As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

  17. The IRSN publishes an assessment of doses received in Japan by external irradiation due to radioactive deposits caused by the Fukushima-Daiichi power plant accident; L'IRSN publie une estimation des doses recues au Japon par irradiation externe due aux depots radioactifs provoques par l'accident de la centrale de Fukushima-Daiichi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This document first describes how dry and wet radioactive deposits are formed. It also indicates their main components: iodine 131 and 132, caesium 134, 136 and 137, tellurium 132, and barium 140. It describes the different exposure ways due to radioactive deposits in the environment. A map indicates dose level assessments few tens of kilometres around the Fukushima power plant. A brief comment of this map is proposed

  18. Criticality safety concerns of uranium deposits in cascade equipment

    International Nuclear Information System (INIS)

    Plaster, M.J.

    1996-01-01

    The Paducah and Portsmouth Gaseous Diffusion Plants enrich uranium in the 235 U isotope by diffusing gaseous uranium hexafluoride (UF 6 ) through a porous barrier. The UF 6 gaseous diffusion cascade utilized several thousand open-quotes stagesclose quotes of barrier to produce highly enriched uranium (HEU). Historically, Portsmouth has enriched the Paducah Gaseous Diffusion Plant's product (typically 1.8 wt% 235 U) as well as natural enrichment feed stock up to 97 wt%. Due to the chemical reactivity of UF 6 , particularly with water, the formation of solid uranium deposits occur at a gaseous diffusion plant. Much of the equipment operates below atmospheric pressure, and deposits are formed when atmospheric air enters the cascade. Deposits may also be formed from UF 6 reactions with oil, UF 6 reactions with the metallic surfaces of equipment, and desublimation of UF 6 . The major deposits form as a result of moist air in leakage due to failure of compressor casing flanges, blow-off plates, seals, expansion joint convolutions, and instrument lines. This report describes criticality concerns and deposit disposition

  19. Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

    International Nuclear Information System (INIS)

    Tan Chenglong

    2006-01-01

    The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

  20. Nitrogen emission and deposition budget in West and Central Africa

    International Nuclear Information System (INIS)

    Galy-Lacaux, C; Delon, C

    2014-01-01

    Atmospheric nitrogen depends on land surface exchanges of nitrogen compounds. In Sub Saharan Africa, deposition and emission fluxes of nitrogen compounds are poorly quantified, and are likely to increase in the near future due to land use change and anthropogenic pressure. This work proposes an estimate of atmospheric N compounds budget in West and Central Africa, along an ecosystem transect, from dry savanna to wet savanna and forest, for years 2000−2007. The budget may be considered as a one point in time budget, to be included in long term studies as one of the first reference point for Sub Saharan Africa. Gaseous dry deposition fluxes are estimated by considering N compounds concentrations measured in the frame of the IDAF network (IGAC/DEBITS/AFrica) at the monthly scale and modeling of deposition velocities at the IDAF sites, taking into account the bi directional exchange of ammonia. Particulate dry deposition fluxes are calculated using the same inferential method. Wet deposition fluxes are calculated from measurements of ammonium and nitrate chemical content in precipitations at the IDAF sites combined with the annual rainfall amount. In terms of emission, biogenic NO emissions are simulated at each IDAF site with a surface model coupled to an emission module elaborated from an artificial neural network equation. Ammonia emissions from volatilization are calculated from literature data on livestock quantity in each country and N content in manure. NO x and NH 3 emission from biomass burning and domestic fires are estimated from satellite data and emission factors. The total budget shows that emission sources of nitrogen compounds are in equilibrium with deposition fluxes in dry and wet savannas, with respectively 7.40 (±1.90) deposited and 9.01 (±3.44) kgN ha −1 yr −1 emitted in dry savanna, 8.38 (±2.04) kgN ha −1 yr −1 deposited and 9.60 (±0.69) kgN ha −1 yr −1 emitted in wet savanna. In forested ecosystems, the total budget is dominated

  1. Identification of Non-Faradaic Processes by Measurement of the Electrochemical Peltier Heat during the Silver Underpotential Deposition on Au(111).

    Science.gov (United States)

    Frittmann, Stefan; Halka, Vadym; Schuster, Rolf

    2016-04-04

    We measured the heat which is reversibly exchanged during the course of an electrochemical surface reaction, i.e., the deposition/dissolution of the first two monolayers of Ag on a Au(111) surface in (bi)sulfate and perchlorate containing electrolytes. The reversibly exchanged heat corresponds to the Peltier heat of the reaction and is linearly related to its entropy change, including also non-Faradaic side processes. Hence, the measurement of the Peltier heat provides thermodynamic information on the electrochemical processes which is complementary to the current-potential relations usually obtained by conventional electrochemical methods. From the variation of the molar Peltier heat during the various stages of the deposition reaction we inferred that co-adsorption processes of anions and Ag do not play a prominent role, while we find strong indications for a charge neutral substitution reaction of adsorbed anions by hydroxide, which would not show up in cyclic voltammetry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. GYPSUM DEPOSITS IN THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Anto Gabrić

    2002-12-01

    Full Text Available The occurences and deposits of gypsum can be found in big karst poljes (Sinjsko, Vrličko, Petrovo, Kosovo and Kninsko as well as in tectonnically predestined river valleys of Zrmanja, Butišnica and Una. There also appear spatially localized occurences on the island of Vis and in the vicinity of Samobor. Evaporites (gypsum and anhydrite with adjoining overlying clastic rocks (red sandstones, siltites and pelites, carbonate rocks (dolomites and limestones and porous carbonate breccias (Rauhwackes were deposited during the period of Upper Permian. The recent position of the Upper Permian beds is a result of complex tectonic, particularly neotectonic, movements and diapiric displacements. Evaporites were deposited in marginal areas of the epicontinental marine basin, in a period of favourable conditions for the sabkha and playa sedimentation due to the continuous shoreline progradation. The Upper Permian age of these sediments in Dalmatio is proved by the characteristic mineral paragenesis and palinological determinations in elastics rocks, as well as by isotope analyses of sulphure in gypsum. Gypsum is a significant ore mineral resource in building, cement production, as well as in a number of tehnological processes used in chemical industry and elsewhere. According to the recent investigations gypsum is predestined to serve as an ore mineral resource of significant perspectives (the paper is published in Croatian.

  3. Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

    Science.gov (United States)

    Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

    1995-01-01

    The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

  4. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    Science.gov (United States)

    Kundrát, Vojtěch; Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin; Sullivan, John; Ye, Haitao

    2015-04-01

    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) - tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  5. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    Energy Technology Data Exchange (ETDEWEB)

    Kundrát, Vojtěch; Sullivan, John; Ye, Haitao, E-mail: h.ye@aston.ac.uk [School of Engineering and Applied Science, Aston University, Birmingham, B4 7ET (United Kingdom); Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin [Miba Coating Group: Teer Coatings Ltd, West-Stone-House, West-Stone, Berry-Hill-Industrial-Estate, WR9 9AS, Droitwich (United Kingdom)

    2015-04-15

    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) – tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  6. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    Directory of Open Access Journals (Sweden)

    Vojtěch Kundrát

    2015-04-01

    Full Text Available Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42 substrates using a multi-structured molybdenum (Mo – tungsten (W interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  7. Experience in oil field processing of gas and condensate at the Shatlyk deposits

    Energy Technology Data Exchange (ETDEWEB)

    Dalmatov, V.V.; Chernikov, Ye.I.; Govorun, V.P.; Turevskiy, Ye.N.

    1983-01-01

    The operation of installations for preparing gas are analyzed, along with the operation of individual technological devices at the Shatlyk deposit, the basic things which hinder the support of the designed low temperature conditions are shown and recommendations for standardizing the operation of the technological installations are given. Experience in the operation of the gas preparation installations at the Shatlyk deposit is recommended for use in deposits being introduced into development.

  8. Inkjet printing of aqueous rivulets: Formation, deposition, and applications

    Science.gov (United States)

    Bromberg, Vadim

    The past two decades have seen an explosion of research and development into nanotechnology, ranging from synthesis of novel materials that exhibit unique behavior to the assembly of fully functional devices that hold the potential to benefit all sectors of industry and society as a whole. One significant challenge for this emerging technology is the scaling of newly developed processes to the industrial level where manufacturing should be cheap, fast and with high throughput. One approach to this problem has been to develop processes of material deposition and device fabrication via solution-based additive manufacturing techniques such as printing. Specifically, it is envisioned that (in)organic functional nanomaterial that can be processed into solution form can be deposited in a precise manner (i.e., printed) onto sheets of flexible plastic/glass in a process similar to the printing of newspaper (formally, the process is dubbed Roll-to-Roll). This work is focused on experimentally studying and developing one type of solution-based material deposition technique---drop-on-demand ink-jet printing. This technique allows highly-repeatable deposition of small (pico-liter) droplets of functional ink in precise locations on a given target substrate. Although the technology has been in existence and in continuous use for many decades in the paper graphics industry, its application to nanotechnology-based fabrication processes on non-porous substrates presents many challenges stemming from the coupling of the wetting, material transport, evaporation and solid deposition phenomena that occur when printing patterns more complex than single droplets. The focus of this research has been to investigate these phenomena for the case of printed rivulets of water-based inks. A custom ink-jet apparatus has been assembled to allow direct optical observation of the flow and deposition that occur during printing. Experimental results show the importance of substrate surface energy and

  9. Electrical and optical characteristics of ITO films by pulsed laser deposition using a 10 wt.% SnO2-doped In2O3 ceramic target

    International Nuclear Information System (INIS)

    Kim, Sang Hyeob; Park, Nae-Man; Kim, TaeYoub; Sung, GunYong

    2005-01-01

    We have investigated the effect of the oxygen pressure and the deposition temperature on the electrical and optical properties of the Sn-doped indium oxide (ITO) films on quartz glass substrate by pulsed laser deposition (PLD) using a 10 wt.% SnO 2 -doped In 2 O 3 target. The resistivity and the carrier concentration of the films were decreased due to the decrease of the oxygen vacancy while increasing the oxygen pressure. With increasing deposition temperature, the resistivity of the films was decreased and the carrier concentration was increased due to the grain growth and the enhancement of the Sn diffusion. We have optimized the PLD process to deposit a highly conductive and transparent ITO film, which shows the optical transmittance of 88% and the resistivity of 2.49x10 -4 Ω cm for the film thickness of 180 nm

  10. Dry deposition models for radionuclides dispersed in air: a new approach for deposition velocity evaluation schema

    Science.gov (United States)

    Giardina, M.; Buffa, P.; Cervone, A.; De Rosa, F.; Lombardo, C.; Casamirra, M.

    2017-11-01

    In the framework of a National Research Program funded by the Italian Minister of Economic Development, the Department of Energy, Information Engineering and Mathematical Models (DEIM) of Palermo University and ENEA Research Centre of Bologna, Italy are performing several research activities to study physical models and mathematical approaches aimed at investigating dry deposition mechanisms of radioactive pollutants. On the basis of such studies, a new approach to evaluate the dry deposition velocity for particles is proposed. Comparisons with some literature experimental data show that the proposed dry deposition scheme can capture the main phenomena involved in the dry deposition process successfully.

  11. Morphosedimentary and hydrographic features of the northern Argentine margin: The interplay between erosive, depositional and gravitational processes and its conceptual implications

    Science.gov (United States)

    Preu, Benedict; Hernández-Molina, F. Javier; Violante, Roberto; Piola, Alberto R.; Paterlini, C. Marcelo; Schwenk, Tilmann; Voigt, Ines; Krastel, Sebastian; Spiess, Volkhard

    2013-05-01

    Bottom currents and their margin-shaping character became a central aspect in the research field of sediment dynamics and paleoceanography during the last decades due to their potential to form large contourite depositional systems (CDS), consisting of both erosive and depositional features. A major CDS at the northern Argentine continental margin was studied off the Rio de la Plata River by means of seismo- and hydro-acoustic methods including conventional and high-resolution seismic, parametric echosounder and single and swath bathymetry. Additionally, hydrographic data were considered allowing jointly interpretation of morphosedimentary features and the oceanographic framework, which is dominated by the presence of the dynamic and highly variable Brazil-Malvinas Confluence. We focus on three regional contouritic terraces identified on the slope in the vicinity of the Mar del Plata Canyon. The shallowest one, the La Plata Terrace (˜500 m), is located at the Brazil Current/Antarctic Intermediate Water interface characterized by its deep and distinct thermocline. In ˜1200 m water depth the Ewing Terrace correlates with the Antarctic Intermediate Water/Upper Circumpolar Deep Water interface. At the foot of the slope in ˜3500 m the Necochea Terrace marks the transition between Lower Circumpolar Deep Water and Antarctic Bottom Water during glacial times. Based on these correlations, a comprehensive conceptual model is proposed, in which the onset and evolution of contourite terraces is controlled by short- and long-term variations of water mass interfaces. We suggest that the terrace genesis is strongly connected to the turbulent current pattern typical for water mass interfaces. Furthermore, the erosive processes necessary for terrace formation are probably enhanced due to internal waves, which are generated along strong density gradients typical for water mass interfaces. The terraces widen through time due to locally focused, partly helical currents along the

  12. Modeling of thermophoretic deposition of aerosols in nuclear reactor containments

    International Nuclear Information System (INIS)

    Fernandes, A.; Loyalka, S.K.

    1996-01-01

    Aerosol released in postulated or real nuclear reactor accidents can deposit on containment surfaces via motion induced by temperature gradients in addition to the motion due to diffusion and gravity. The deposition due to temperature gradients is known as thermophoretic deposition, and it is currently modeled in codes such as CONTAIN in direct analogy with heat transfer, but there have been questions about such analogies. This paper focuses on a numerical solution of the particle continuity equation in laminar flow condition characteristics of natural convection. First, the thermophoretic deposition rate is calculated as a function of the Prandtl and Schmidt numbers, the thermophoretic coefficient K, and the temperature difference between the atmosphere and the wall. Then, the cases of diffusion alone and a boundary-layer approximation (due to Batchelor and Shen) to the full continuity equation are considered. It is noted that an analogy with heat transfer does not hold, but for the circumstances considered in this paper, the deposition rates from the diffusion solution and the boundary-layer approximation can be added to provide reasonably good agreement (maximum deviation 30%) with the full solution of the particle continuity equation. Finally, correlations useful for implementation in the reactor source term codes are provided

  13. Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

    International Nuclear Information System (INIS)

    Hoeve, J.

    1980-01-01

    Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

  14. Low-temperature atomic layer deposition of TiO2 thin layers for the processing of memristive devices

    International Nuclear Information System (INIS)

    Porro, Samuele; Conti, Daniele; Guastella, Salvatore; Ricciardi, Carlo; Jasmin, Alladin; Pirri, Candido F.; Bejtka, Katarzyna; Perrone, Denis; Chiolerio, Alessandro

    2016-01-01

    Atomic layer deposition (ALD) represents one of the most fundamental techniques capable of satisfying the strict technological requirements imposed by the rapidly evolving electronic components industry. The actual scaling trend is rapidly leading to the fabrication of nanoscaled devices able to overcome limits of the present microelectronic technology, of which the memristor is one of the principal candidates. Since their development in 2008, TiO 2 thin film memristors have been identified as the future technology for resistive random access memories because of their numerous advantages in producing dense, low power-consuming, three-dimensional memory stacks. The typical features of ALD, such as self-limiting and conformal deposition without line-of-sight requirements, are strong assets for fabricating these nanosized devices. This work focuses on the realization of memristors based on low-temperature ALD TiO 2 thin films. In this process, the oxide layer was directly grown on a polymeric photoresist, thus simplifying the fabrication procedure with a direct liftoff patterning instead of a complex dry etching process. The TiO 2 thin films deposited in a temperature range of 120–230 °C were characterized via Raman spectroscopy and x-ray photoelectron spectroscopy, and electrical current–voltage measurements taken in voltage sweep mode were employed to confirm the existence of resistive switching behaviors typical of memristors. These measurements showed that these low-temperature devices exhibit an ON/OFF ratio comparable to that of a high-temperature memristor, thus exhibiting similar performances with respect to memory applications

  15. Characterization of the acidic cold seep emplaced jarositic Golden Deposit, NWT, Canada, as an analogue for jarosite deposition on Mars

    Science.gov (United States)

    Battler, Melissa M.; Osinski, Gordon R.; Lim, Darlene S. S.; Davila, Alfonso F.; Michel, Frederick A.; Craig, Michael A.; Izawa, Matthew R. M.; Leoni, Lisa; Slater, Gregory F.; Fairén, Alberto G.; Preston, Louisa J.; Banerjee, Neil R.

    2013-06-01

    deposits on Mars. Most terrestrial analogues for Mars jarosites have been identified in temperate environments, where evaporation rates are very high and jarosites form along with other sulfates due to rapid evaporation (e.g. Rio Tinto, Spain; Western Australian acidic saline lake deposits). The GD is a rare example of an analogue site where jarosite precipitates under dominant freezing processes similar to those which could have prevailed on early Mars. Thus, the GD offers a new perspective on jarosite deposition by the upwelling of acidic waters through permafrost at Meridiani Planum and Mawrth Vallis, Mars. The GD also demonstrates that martian deposits may show considerably more chemical and mineral variability than indicated by the current remote sensing data sets.

  16. Eemian Rhine delta architecture in The Netherlands: facies distribution, deposit characteristics and preservation potential in an near-coastal deltaic setting

    NARCIS (Netherlands)

    Peeters, J.

    2012-01-01

    Within near-coastal environments, the fluvial-tidal transition zone is one of the most complex zones due to mixture of processes and sediments of different source and depositional styles. Despite a large number of excellent Holocene fluvial-estuarine cases, transferring sedimentary concepts into

  17. Development of Cotton Fabrics with Durable UV Protective and Self-cleaning Property by Deposition of Low TiO2 Levels through Sol-gel Process.

    Science.gov (United States)

    Mishra, Anu; Butola, Bhupendra Singh

    2018-01-19

    In this article, the deposition of TiO 2 on cotton fabric using sol-gel technique has been described. Various process routes (pad-dry-cure, pad-dry-hydrothermal and pad-dry-solvothermal) were examined to impart a stable coating of TiO 2 on fabric. The role of precursor concentration, process temperature and time of treatment were studied to aim at a wash durable, UV protective and self-cleaning property in the treated fabric. EDX and ICP-MS techniques were used to examine the add-on percentage of TiO 2 on cotton fabrics treated via different routes. It has been found that the TiO 2 remains largely amorphous and nondurable if it is given a short thermal treatment. To convert the deposited TiO 2 to its anatase crystal form, a prolonged hydrothermal treatment for at least 3 h needs to be given. TiO 2 deposition levels of less than 0.1% were found to be effective in imparting reasonable degree of UV protection and self-cleaning property to the cotton fabric. The self-cleaning ability of the treated fabric against coffee stain was also studied and was found to be related to the process route and the deposition levels of TiO 2 . © 2018 The American Society of Photobiology.

  18. Power Deposition due to Muon Decay Losses in a Neutrino Factory

    CERN Document Server

    Keil, Eberhard

    2000-01-01

    The power in the charged muon decay products, deposited per unit distance, depends on the muon energy only through the relativistic factor beta. For a typical neutrino factory it is about one Watt/m, multiplied by the number of passes through a particular component. The power is highest in the muon decay ring, where the muon lifetime cooresponds to about 150 turns. The electrons or positrons from muon decay in the long straight section may remain inside the vacuum chamber, until they are lost at the beginning of the arcs, because of their large energy errors, that are enhanced by synchrotron radiation losses. The power losses along the straight section and the arcs are studied by computer simulation, and the results are presented. About two thirds of the power ends up in the straight section, the remainder in the matching section and in the first half of the dispersion suppressor.

  19. Global deposition of airborne dioxin.

    Science.gov (United States)

    Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

    2013-10-15

    We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Thermal plasma spheroidization and spray deposition of barium titanate powder and characterization of the plasma sprayable powder

    Energy Technology Data Exchange (ETDEWEB)

    Pakseresht, A.H., E-mail: amirh_pak@yahoo.com [Department of Ceramics, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Rahimipour, M.R. [Department of Ceramics, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Vaezi, M.R. [Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Salehi, M. [Department of Materials Engineering, Isfahan University of Technology, P.O. Box 84156-83111, Isfahan (Iran, Islamic Republic of)

    2016-04-15

    In this paper, atmospheric plasma spray method was used to produce dense plasma sprayable powder and thick barium titanate film. In this regard, the commercially feedstock powders were granulated and spheroidized by the organic binder and the thermal spray process, respectively. Scanning electron microscopy was used to investigate the microstructure of the produced powders and the final deposits. X-ray diffraction was also implemented to characterize phase of the sprayed powder. The results indicated that spheroidized powder had suitable flowability as well as high density. The micro-hardness of the film produced by the sprayed powders was higher than that of the film deposited by the irregular granules. Additionally, relative permittivity of the films was increased by decreasing the defects from 160 to 293 for film deposited using spheroidized powder. The reduction in the relative permittivity of deposits, in comparison with the bulk material, was due to the existence of common defects in the thermal spray process. - Highlights: • We prepare sprayable BaTiO{sub 3} powder with no or less inside voids for plasma spray application for first time. • The sprayable powder has good flow characteristics and high density. • Powder spheroidization via plasma spray improves the hardness and dielectric properties of the deposited film.

  1. Thermal plasma spheroidization and spray deposition of barium titanate powder and characterization of the plasma sprayable powder

    International Nuclear Information System (INIS)

    Pakseresht, A.H.; Rahimipour, M.R.; Vaezi, M.R.; Salehi, M.

    2016-01-01

    In this paper, atmospheric plasma spray method was used to produce dense plasma sprayable powder and thick barium titanate film. In this regard, the commercially feedstock powders were granulated and spheroidized by the organic binder and the thermal spray process, respectively. Scanning electron microscopy was used to investigate the microstructure of the produced powders and the final deposits. X-ray diffraction was also implemented to characterize phase of the sprayed powder. The results indicated that spheroidized powder had suitable flowability as well as high density. The micro-hardness of the film produced by the sprayed powders was higher than that of the film deposited by the irregular granules. Additionally, relative permittivity of the films was increased by decreasing the defects from 160 to 293 for film deposited using spheroidized powder. The reduction in the relative permittivity of deposits, in comparison with the bulk material, was due to the existence of common defects in the thermal spray process. - Highlights: • We prepare sprayable BaTiO_3 powder with no or less inside voids for plasma spray application for first time. • The sprayable powder has good flow characteristics and high density. • Powder spheroidization via plasma spray improves the hardness and dielectric properties of the deposited film.

  2. Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane : The role of dissociative ionization and dissociative electron attachment in the deposition process

    NARCIS (Netherlands)

    Ragesh Kumar, T. P.; Hari, S.; Damodaran, Krishna K.; Ingólfsson, Oddur; Hagen, C.W.

    2017-01-01

    We present first experiments on electron beam induced deposition of silacyclohexane (SCH) and dichlorosilacyclohexane (DCSCH) under a focused high-energy electron beam (FEBID). We compare the deposition dynamics observed when growing pillars of high aspect ratio from these compounds and we

  3. Structurally controlled deposition of silicon onto nanowires

    Science.gov (United States)

    Wang, Weijie; Liu, Zuqin; Han, Song; Bornstein, Jonathan; Stefan, Constantin Ionel

    2018-03-20

    Provided herein are nanostructures for lithium ion battery electrodes and methods of fabrication. In some embodiments, a nanostructure template coated with a silicon coating is provided. The silicon coating may include a non-conformal, more porous layer and a conformal, denser layer on the non-conformal, more porous layer. In some embodiments, two different deposition processes, e.g., a PECVD layer to deposit the non-conformal layer and a thermal CVD process to deposit the conformal layer, are used. Anodes including the nanostructures have longer cycle lifetimes than anodes made using either a PECVD or thermal CVD method alone.

  4. Influence of deposition temperature of thermal ALD deposited Al2O3 films on silicon surface passivation

    Directory of Open Access Journals (Sweden)

    Neha Batra

    2015-06-01

    Full Text Available The effect of deposition temperature (Tdep and subsequent annealing time (tanl of atomic layer deposited aluminum oxide (Al2O3 films on silicon surface passivation (in terms of surface recombination velocity, SRV is investigated. The pristine samples (as-deposited show presence of positive fixed charges, QF. The interface defect density (Dit decreases with increase in Tdep which further decreases with tanl up to 100s. An effective surface passivation (SRV<8 cm/s is realized for Tdep ≥ 200 °C. The present investigation suggests that low thermal budget processing provides the same quality of passivation as realized by high thermal budget process (tanl between 10 to 30 min.

  5. Microbial activity in an acid resin deposit: Biodegradation potential and ecotoxicology in an extremely acidic hydrocarbon contamination

    International Nuclear Information System (INIS)

    Kloos, Karin; Schloter, Michael; Meyer, Ortwin

    2006-01-01

    Acid resins are residues produced in a recycling process for used oils that was in use in the forties and fifties of the last century. The resin-like material is highly contaminated with mineral oil hydrocarbons, extremely acidic and co-contaminated with substituted and aromatic hydrocarbons, and heavy metals. To determine the potential for microbial biodegradation the acid resin deposit and its surroundings were screened for microbial activity by soil respiration measurements. No microbial activity was found in the core deposit. However, biodegradation of hydrocarbons was possible in zones with a lower degree of contamination surrounding the deposit. An extreme acidophilic microbial community was detected close to the core deposit. With a simple ecotoxicological approach it could be shown that the pure acid resin that formed the major part of the core deposit, was toxic to the indigenous microflora due to its extremely low pH of 0-1. - Acidity is the major toxic factor of the extremely hydrophobic and acidic mixed contamination found in an acid resin deposit

  6. Assessment of the dose to a representative Japanese due to stationary release of tritium to the environment

    International Nuclear Information System (INIS)

    Saito, Masahiro

    2005-01-01

    The computer program TriStat was applied to estimate the dose to a representative Japanese due to a stationary release of tritium as HTO and/or HT to the atmosphere from nuclear facilities. In TriStat, the air tritium concentration is estimated by a Gaussian dispersion model. The tritium deposition to the soil was assumed to occur both by dry and wet deposition processes of atmospheric tritium. The primary process of tritium transfer to human body is assumed to take place through a local food-chain in the contaminated area. Tritium concentrations in soil, vegetables and forage were estimated as the tritium concentration per water equivalent. The food chain was modeled by assuming a vegetable compartment and an animal-food compartment. By using TriStat the annual dose to the representative Japanese was evaluated for stationary release of tritium as a function of the distance from a release point. The dose contribution from drinking water was neglected, since the drinking water is generally supplied as tap water or as commercial bottled water. In the case of HT release, the committed dose due to tritium intake through breathing and skin absorption was found to be of minor importance. (author)

  7. Growth model and structure evolution of Ag layers deposited on Ge films.

    Science.gov (United States)

    Ciesielski, Arkadiusz; Skowronski, Lukasz; Górecka, Ewa; Kierdaszuk, Jakub; Szoplik, Tomasz

    2018-01-01

    We investigated the crystallinity and optical parameters of silver layers of 10-35 nm thickness as a function 2-10 nm thick Ge wetting films deposited on SiO 2 substrates. X-ray reflectometry (XRR) and X-ray diffraction (XRD) measurements proved that segregation of germanium into the surface of the silver film is a result of the gradient growth of silver crystals. The free energy of Ge atoms is reduced by their migration from boundaries of larger grains at the Ag/SiO 2 interface to boundaries of smaller grains near the Ag surface. Annealing at different temperatures and various durations allowed for a controlled distribution of crystal dimensions, thus influencing the segregation rate. Furthermore, using ellipsometric and optical transmission measurements we determined the time-dependent evolution of the film structure. If stored under ambient conditions for the first week after deposition, the changes in the transmission spectra are smaller than the measurement accuracy. Over the course of the following three weeks, the segregation-induced effects result in considerably modified transmission spectra. Two months after deposition, the slope of the silver layer density profile derived from the XRR spectra was found to be inverted due to the completed segregation process, and the optical transmission spectra increased uniformly due to the roughened surfaces, corrosion of silver and ongoing recrystallization. The Raman spectra of the Ge wetted Ag films were measured immediately after deposition and ten days later and demonstrated that the Ge atoms at the Ag grain boundaries form clusters of a few atoms where the Ge-Ge bonds are still present.

  8. Progress Toward Meeting NIF Specifications for Vapor Deposited Polyimide Ablator Coatings

    International Nuclear Information System (INIS)

    Letts, Stephan A.; Anthamatten, Mitchell; Buckley, Steven R.; Fearon, Evelyn; Nissen, April E.H.; Cook, Robert C.

    2004-01-01

    We are developing an evaporative coating technique for deposition of thick polyimide (PI) ablator layers on ICF targets. The PI coating technique utilizes stoichiometrically controlled fluxes from two Knudsen cell evaporators containing a dianhydride and a diamine to deposit a polyamic acid (PAA) coating. Heating the PAA coating to 300 deg. C converts the PAA coating to a polyimide. Coated shells are rough due to particles on the substrate mandrels and from damage to the coating caused by the agitation used to achieve a uniform coating. We have developed a smoothing process that exposes an initially rough PAA coated shell to solvent vapor using gas levitation. We found that after smoothing the coatings developed a number of wide (low-mode) defects. We have identified two major contributors to low-mode roughness: surface hydrolysis, and deformation during drying/curing. By minimizing air exposure prior to vapor smoothing, avoiding excess solvent sorption during vapor smoothing, and using slow drying we are able to deposit and vapor smooth coatings 160 μm thick with a surface roughness less than 20 nm RMS

  9. Quartz-pebble-conglomerate gold deposits: Chapter P in Mineral deposit models for resource assessment

    Science.gov (United States)

    Taylor, Ryan D.; Anderson, Eric D.

    2018-05-17

    Quartz-pebble-conglomerate gold deposits represent the largest repository of gold on Earth, largely due to the deposits of the Witwatersrand Basin, which account for nearly 40 percent of the total gold produced throughout Earth’s history. This deposit type has had a controversial history in regards to genetic models. However, most researchers conclude that they are paleoplacer deposits that have been modified by metamorphism and hydrothermal fluid flow subsequent to initial sedimentation.The deposits are found exclusively within fault-bounded depositional basins. The periphery of these basins commonly consists of granite-greenstone terranes, classic hosts for lode gold that source the detrital material infilling the basin. The gold reefs are typically located along unconformities or, less commonly, at the top of sedimentary beds. Large quartz pebbles and heavy-mineral concentrates are found associated with the gold. Deposits that formed prior to the Great Oxidation Event (circa 2.4 giga-annum [Ga]) contain pyrite, whereas younger deposits contain iron oxides. Uranium minerals and hydrocarbons are also notable features of some deposits.Much of the gold in these types of deposits forms crystalline features that are the product of local remobilization. However, some gold grains preserve textures that are undoubtedly of detrital origin. Other heavy minerals, such as pyrite, contain growth banding that is truncated along broken margins, which indicates that they were transported into place as opposed to forming by in situ growth in a hydrothermal setting.The ore tailings associated with these deposits commonly contain uranium-rich minerals and sulfides. Oxidation of the sulfides releases sulfuric acid and mobilizes various metals into the environment. The neutralizing potential of the tailings is minimal, since carbonate minerals are rare. The continuity of the tabular ore bodies, such as those of the Witwatersrand Basin, has allowed these mines to be the deepest in

  10. An iron-deficient diet stimulates the onset of the hepatitis due to hepatic copper deposition in the Long-Evans Cinnamon (LEC) rat

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Naoki; Sugawara, Chieko [Sapporo Medical Univ. (Japan). Dept. of Public Health

    1999-09-01

    To study effects of dietary Cu and Fe levels on the onset of hepatitis in Long-Evans Cinnamon (LEC) rats, female rats (40 days old) were fed a semipurified diet containing 0.1 or 10 mg Cu/kg and 1.5 or 150 mg Fe/kg in a 2 x 2 factorial arrangement for 35 days. At 75 days after birth, LEC rats (+Cu-Fe) fed a Cu-sufficient but Fe-deficient diet (Cu, 10 mg/kg; Fe, 1.5 mg/kg) showed jaundice, with lethargy, anorexia, and malaise. The biochemical variables relating to liver function were significantly increased compared to three other groups, a Cu- and Fe-deficient (-Cu-Fe) group, a Cu-deficient but Fe-sufficient (-Cu+Fe) group, and a Cu and Fe sufficient (+Cu+Fe) group. Furthermore, the +Cu-Fe rat liver showed massive necrosis with huge nuclei. The other three groups presented no biochemical and histological findings of hepatitis. Hepatic Cu and metallothionein concentrations were 289 {+-} 87 (mean {+-} SD) {mu}g/g liver and 8.7 {+-} 1.8 mg/g liver, respectively, in the +Cu-Fe rats. However, in the +Cu+Fe group the values were 196 {+-} 28 {mu}g Cu/g liver and 10.8 {+-} 1.0 mg/g liver. Hepatic Fe deposition was not influenced significantly by the dietary Cu level. The +Cu-Fe group with jaundice showed the highest free Cu concentration in the liver among the four groups, but the hepatic free Fe concentration was similar to those in the -Cu+Fe and +Cu+Fe groups. Our results indicate that an Fe-deficient diet enhances the deposition of hepatic Cu due to increased absorption of Cu from the gastrointestinal tract. This deposition stimulated the onset of hepatitis. (orig.)

  11. Thorium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main occurences of the thorium minerals of the Argentine Republic which have not been exploited, due to their reduced volume, are described. The thoriferous deposits have three genetic types: pegmatitic, hydrothermal and detritic, being the most common minerals: monazite, thorite and thorogummite. The most important thorium accumulations are located in Salta, being of less importance those of Cordoba, Jujuy and San Juan. (M.E.L.) [es

  12. EDDA: integrated simulation of debris flow erosion, deposition and property changes

    Science.gov (United States)

    Chen, H. X.; Zhang, L. M.

    2014-11-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of debris flow mixture is determined at limit equilibrium using the Mohr-Coulomb equation, which is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, a variable time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional dam-break water flow and a one-dimensional debris flow with constant properties. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

  13. Insights into the IASB due process: the influence of country characteristics on constituents’ formal participation

    Directory of Open Access Journals (Sweden)

    Karsten Eisenschmidt

    2017-12-01

    Full Text Available The paper explores the impact of country characteristics on constituents’ formal participation in the IASB’s due process. We hypothesize that there is an association between the level of constituents’ partic- ipation and (1 the level of economic development, and (2 the cultural characteristics of the country of origin. We use a number of comment letters (CLs and their length as proxies for constituents’ formal participation in the IASB’s due process. The results indicate that economic development (equity market capitalization is the most important explanatory factor for the different levels of participation. In con- trast, the cultural characteristics measured by Hofstede’s cultural framework can only partially explain that differences. Only individualism is a significant positive influence factor for the level of constituents’ participation. The results of our descriptive analysis for the CLs and the information input provided show that there is still a lack of participation in the IASB’s due process. Despite the huge impact of accounting norms on societies, only a limited number of constituents participate, and some constituent groups, like users or academics, participate less.

  14. EDDA 1.0: integrated simulation of debris flow erosion, deposition and property changes

    Science.gov (United States)

    Chen, H. X.; Zhang, L. M.

    2015-03-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA (Erosion-Deposition Debris flow Analysis), is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of the debris flow mixture determined at limit equilibrium using the Mohr-Coulomb equation is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, an adaptive time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional debris flow with constant properties and a two-dimensional dam-break water flow. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

  15. High performance emitter for thermionic diode obtained by chemical vapor deposition

    International Nuclear Information System (INIS)

    Faron, R.; Bargues, M.; Durand, J.P.; Gillardeau, J.

    1973-01-01

    Vapor deposition process conditions presently known for tungsten and molybdenum (specifically the range of high temperatures and low pressures) permit the achievement of high performance thermionic emitters when used with an appropriate technology. One example of this uses the following series of successive vapor deposits, the five last vapor deposits constituting the fabrication of the emitting layer: Mo deposit for the formation of the nuclear fuel mechanical support; Mo deposit, which constitutes the sheath of the nuclear fuel; epitaxed Mo--W alloy deposit; epitaxed tungsten deposit; fine-grained tungsten deposit; and tungsten deposit with surface orientation according to plane (110)W. In accordance with vapor deposition techniques previously developed, such a sequence of deposits can easily be achieved with the same equipment, even without having to take out the part during the course of the process. (U.S.)

  16. Long-term deposition patterns of airborne wastes in the North-East of Estonia

    International Nuclear Information System (INIS)

    Kaasik, M.; Kaasik, H.

    1999-01-01

    The deposition loads of fly ash and sulfur have been high in the North-East Estonia since the late fifties, when the oil shale energetics, chemical and cement industry achieved the remarkable extent. The combined effects of both pollutants have seriously damaged sensitive ecosystems (forest on podsolic soils and bog). Most of sulphur deposition is closely related to the oil shale fly ash deposition. The main effects are related with alkalisation due to accumulation of fly ash components and the Sphagnum growth inhibition due to sulfur load. These effects have the time scale of several years or even more. The pollution loads have been changed during recent 40 years due to launching and reconstruction of enterprises (incl. purification systems) and variations of production capacity. First representative data on air pollution deposition originate from the middle of eighties. Only model estimations could be used to quantify the deposition fluxes before that time, as well as for assessing the future scenarios

  17. Dispersion, deposition and resuspension of atmospheric contaminants

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The following topics are discussed: dry deposition, oil shale fugitive air emissions, particle resuspension and translocation, theoretical studies and applications, and processing of emissions by clouds and precipitation. The concentration of contaminant species in air is governed by the rate of input from sources, the rate of dilution or dispersion as a result of air turbulence, and the rate of removal to the surface by wet and dry deposition processes. Once on the surface, contaminants also may be resuspended, depending on meteorological and surface conditions. An understanding of these processes is necessary for accurate prediction of exposures of hazardous or harmful contaminants to humans, animals, and crops. In the field, plume dispersion and plume depletion by dry deposition were studied by the use of tracers. Dry deposition was investigated for particles of both respiration and inhalation interest. Complementary dry deposition studies of particles to rock canopies were conducted under controlled conditions in a wind tunnel. Because of increasing concern about hazardous, organic gases in the atmosphere some limited investigations of the dry deposition of nitrobenzene to a lichen mat were conducted in a stirred chamber. Resuspension was also studied using tracers and contaminated surfaces and in the wind tunnel. The objective of the resuspension studies was to develop and verify models for predicting the airborne concentrations of contaminants over areas with surface contamination, develop resuspension rate predictors for downwind transport, and develop predictors for resuspension input to the food chain. These models will be of particular relevance to the evaluation of deposition and resuspension of both radionuclides and chemical contaminants

  18. Characterization of aluminum/aluminum nitride coatings sputter deposited using the pulsed-gas process

    International Nuclear Information System (INIS)

    Springer, R.W.; Hosford, C.D.

    1981-01-01

    A dc triode magnetron has been used to produce freestanding Al/Al + AlN lamellar foils by sputter deposition. The 5-μm-thick foils produced on both flat substrates as well as curved substrates exhibited good specularity as well as excellent mechanical properties. The pulse spacing was varied from none to 100-nm spacing. The yield strength of the material was found to obey the Hall-Petch relation sigma/sub ys/ = 230 + .07/d/sup 1/2/, where sigma/sub ys/ is in MPa. Auger electron Spectroscopy and Secondary Ion Mass Spectroscopy indicate that the large flow stress of 230 MPa must be due to grain refinement of the extended source and not an impurity effect. The result is that limitations of masking found in uniaxial flux sources for curved surfaces can be removed allowing the high quality coating of more general shapes

  19. Hydrothermal processes in the Edmond deposits, slow- to intermediate-spreading Central Indian Ridge

    Science.gov (United States)

    Cao, Hong; Sun, Zhilei; Zhai, Shikui; Cao, Zhimin; Jiang, Xuejun; Huang, Wei; Wang, Libo; Zhang, Xilin; He, Yongjun

    2018-04-01

    The Edmond hydrothermal field, located on the Central Indian Ridge (CIR), has a distinct mineralization history owing to its unique magmatic, tectonic, and alteration processes. Here, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this area. Based on the mineralogical investigations, the Edmond hydrothermal deposits comprise of high-temperature Fe-rich massive sulfides, medium-temperature Zn-rich sulfide chimney and low-temperature Ca-rich sulfate mineral assemblages. According to these compositions, three distinctive mineralization stages have been identified: (1) low-temperature consisting largely of anhydrite and pyrite/marcasite; (2) medium-high temperature distinguished by the mineral assemblage of pyrite, sphalerite and chalcopyrite; and (3) low-temperature stage characterized by the mineral assemblage of colloidal pyrite/marcasite, barite, quartz, anglesite. Several lines of evidence suggest that the sulfides were influenced by pervasive low-temperature diffuse flows in this area. The hydrothermal deposits are relatively enriched in Fe (5.99-18.93 wt%), Zn (2.10-10.00 wt%) and Ca (0.02-19.15 wt%), but display low Cu (0.28-0.81 wt%). The mineralogical varieties and low metal content of sulfides in the Edmond hydrothermal field both indicate that extensive water circulation is prevalent below the Edmond hydrothermal field. With regard to trace elements, the contents of Pb, Ba, Sr, As, Au, Ag, and Cd are significantly higher than those in other sediment-starved mid-ocean ridges, which is indicative of contribution from felsic rock sources. Furthermore, the multiphase hydrothermal activity and the pervasive water circulation underneath are speculated to play important roles in element remobilization and enrichment. Our findings deepen our understanding about the complex mineralization process in slow- to intermediate-spreading ridges globally.

  20. The application of imperialist competitive algorithm for optimization of deposition rate in submerged arc welding process using TiO2 nano particle

    International Nuclear Information System (INIS)

    Ghaderi, Mohammad Reza; Eslampanah, Amirhossein; Ghaderi, Kianoosh; Aghakhani, Masood

    2015-01-01

    We used a novel optimization algorithm based on the imperialist competitive algorithm (ICA) to optimize the deposition rate in the submerged arc welding (SAW) process. This algorithm offers some advantages such as simplicity, accuracy and time saving. Experiments were conducted based on a five factor, five level rotatable central composite design (RCCD) to collect welding data for deposition rate as a function of welding current, arc voltage, contact tip to plate distance, welding speed and thickness of TiO 2 nanoparticles coated on the plates of mild steel. Furthermore, regression equation for deposition rate was obtained using least squares method. The regression equation as the cost function was optimized using ICA. Ultimately, the levels of input variables to achieve maximum deposition rate were obtained using ICA. Computational results indicate that the proposed algorithm is quite effective and powerful in optimizing the cost function.