Sample records for abrasive grit blasting

  1. Detecting Residues On Grit-Blasted Surfaces

    NASA Technical Reports Server (NTRS)

    Novak, H. L.; Zook, L. M.

    1989-01-01

    Addition of fluorescent or iridescent material to plastic grit particles proposed for detection of grit residues after grit-blast cleaning. Residual films visible by observing grit-blasted surfaces under infrared or ultraviolet light. Plastic grit contains fluorescent or iridescent additive in core and coating. Wherever grit material becomes embedded, additive makes it visible under infrared or ultraviolet light. Applicable to other grit materials, for example fluorescent or iridescent materials added to particles of glass, silicon carbide, aluminum oxide, or zirconium silicate.

  2. Effect of Grit Blasting on Substrate Roughness and Coating Adhesion

    SciTech Connect

    Dominic Varacalle; Donna Guillen; Doug Deason; William Rhodaberger; Elliott Sampson

    2006-09-01

    Statistically designed experiments were performed to compare the surface roughnesses produced by grit blasting A36/1020 steel with different abrasives. Grit blast media, blast pressure, and working distance were varied using a Box-type statistical design of experiment (SDE) approach. The surface textures produced by four metal grits (HG16, HG18, HG25, and HG40) and three conventional grits (copper slag, coal slag, and chilled iron) were compared. Substrate roughness was measured using surface profilometry and correlated with operating parameters. The HG16 grit produced the highest surface roughness of all the grits tested. Aluminum and zinc-aluminum coatings were deposited on the grit-blasted substrates using a Twin-Wire Electric Arc (TWEA) process. Bond strength of the coatings was measured with a portable adhesion tester in accordance with ASTM standard D4541. The coatings on substrates roughened with steel grit exhibit superior bond strength to those on substrates prepared with conventional grit. For aluminum coatings sprayed onto surfaces prepared with the HG16 grit, the bond strength was most influenced by current, spray distance, and spray gun pressure (in that order). The highest bond strength for the zinc-aluminum coatings was attained on surfaces prepared using the metal grits.

  3. Soybean seedlings tolerate abrasion from air-propelled grit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New tools for controlling weeds would be useful for soybean production in organic systems. Air-propelled abrasive grit is one such tool that performs well for in-row weed control in corn, but crop safety in soybean is unknown. We examined responses to abrasion by corn-cob grit of soybean seedlings a...

  4. Abrasion of cemented carbides by small grits

    Microsoft Academic Search

    H Engqvist; N Axén

    1999-01-01

    The abrasion properties of a series of cemented carbides with different carbide grain sizes, different amounts and types of binder phases have been investigated under varied conditions. Abrasion results from other works are also incorporated for comparison reasons. The results are interpreted in the light of a previously published model for the abrasion properties of multiphase materials, although this is

  5. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...with the miner outside the device. (b) Underground areas of underground mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as an abrasive substance in abrasive blasting. [59 FR 8327,...

  6. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...with the miner outside the device. (b) Underground areas of underground mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as an abrasive substance in abrasive blasting. [59 FR 8327,...

  7. Effect of abrasive grit size on wear of manganese-zinc ferrite under three-body abrasion

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1987-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and deformed layers produced in single-crystal Mn-Zn ferrites under three-body abrasion. The abrasion mechanism of Mn-Zn ferrite changes drastically with the size of abrasive grits. With 15-micron (1000-mesh) SiC grits, abrasion of Mn-Zn ferrite is due principally to brittle fracture; while with 4- and 2-micron (4000- and 6000-mesh) SiC grits, abrasion is due to plastic deformation and fracture. Both microcracking and plastic flow produce polycrystalline states on the wear surfaces of single-crystal Mn-Zn ferrites. Coefficient of wear, total thickness of the deformed layers, and surface roughness of the wear surfaces increase markedly with an increase in abrasive grit size. The total thicknesses of the deformed layers are 3 microns for the ferrite abraded by 15-micron SiC, 0.9 microns for the ferrite abraded by 4-micron SiC, and 0.8 microns for the ferrite abraded by 1-micron SiC.

  8. Mechanical assessment of grit blasting surface treatments of dental implants.

    PubMed

    Shemtov-Yona, K; Rittel, D; Dorogoy, A

    2014-11-01

    This paper investigates the influence of surface preparation treatments of dental implants on their potential (mechanical) fatigue failure, with emphasis on grit-blasting. The investigation includes limited fatigue testing of implants, showing the relationship between fatigue life and surface damage condition. Those observations are corroborated by a detailed failure analysis of retrieved fracture dental implants. In both cases, the negative effect of embedded alumina particles related to the grit-blasting process is identified. The study also comprises a numerical simulation part of the grit blasting process that reveals, for a given implant material and particle size, the existence of a velocity threshold, below which the rough surface is obtained without damage, and beyond which the creation of significant surface damage will severely reduce the fatigue life, thus increasing fracture probability. The main outcome of this work is that the overall performance of dental implants comprises, in addition to the biological considerations, mechanical reliability aspects. Fatigue fracture is a central issue, and this study shows that uncontrolled surface roughening grit-blasting treatments can induce significant surface damage which accelerate fatigue fracture under certain conditions, even if those treatments are beneficial to the osseointegration process. PMID:25173238

  9. Grit Blasting Scribes Coats For Tests Of Adhesion

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.

    1991-01-01

    Grit-blasting technique for cutting line gaps in paints, hard coats, lubricants, and other coating films undergoing development. Line gaps cut in chevron patterns, groups of parallel lines, or other prescribed patterns, in preparation for testing adhesions of coats to substrates by attempting to peel patterned areas off with adhesive tapes. Damage to substrate reduced.

  10. PAGMan - propelled abrasive grit to manage weeds in soybean and corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New tools for controlling weeds would be useful for soybean and corn production in organic systems or in systems in which weeds developed resistance to multiple herbicides. Here we report on two developments: (i) the safety to soybean seedlings of using air-propelled abrasive grit (PAG) for managing...

  11. Advances in High Performance Micro Abrasive Blasting

    Microsoft Academic Search

    M. Achtsnick; A. M. Hoogstrate; B. Karpuschewski

    2005-01-01

    Micro abrasive blasting (MAB) has been successfully improved by the introduction of a rectangular Laval nozzle concept. In this paper the earlier presented set of models has been extended to predict the performance of such nozzles. The results of the sub-model for the jet show that its energy intensity is more evenly distributed and at a substantial higher level compared

  12. Surface impurity removal from DIII-D graphite tiles by boron carbide grit blasting

    SciTech Connect

    Lee, R.L.; Hollerbach, M.A.; Holtrop, K.L.; Kellman, A.G.; Taylor, P.L.; West, W.P.

    1993-11-01

    During the latter half of 1992, the DIII-D tokamak at General Atomics (GA) underwent several modifications of its interior. One of the major tasks involved the removal of accumulated metallic impurities from the surface of the graphite tiles used to line the plasma facing surfaces inside of the tokamak. Approximately 1500 graphite tiles and 100 boron nitride tiles from the tokamak were cleaned to remove the metallic impurities. The cleaning process consisted of several steps: the removed graphite tiles were permanently marked, surface blasted using boron carbide (B{sub 4}C) grit media (approximately 37 {mu}m. diam.), ultrasonically cleaned in ethanol to remove loose dust, and outgassed at 1000{degrees}C. Tests were done using, graphite samples and different grit blaster settings to determine the optimum propellant and abrasive media pressures to remove a graphite layer approximately 40-50 {mu}m deep and yet produce a reasonably smooth finish. EDX measurements revealed that the blasting technique reduced the surface Ni, Cr, and Fe impurity levels to those of virgin graphite. In addition to the surface impurity removal, tritium monitoring was performed throughout the cleaning process. A bubbler system was set up to monitor the tritium level in the exhaust gas from the grit blaster unit. Surface wipes were also performed on over 10% of the tiles. Typical surface tritium concentrations of the tiles were reduced from about 500 dpm/100 cm{sup 2} to less than 80 dpm/100 cm{sup 2} following the cleaning. This tile conditioning, and the installation of additional graphite tiles to cover a high fraction of the metallic plasma facing surfaces, has substantially reduced metallic impurities in the plasma discharges which has allowed rapid recovery from a seven-month machine opening and regimes of enhanced plasma energy confinement to be more readily obtained. Safety issues concerning blaster operator exposure to carcinogenic metals and radioactive tritium will also be addressed.

  13. Diffuse reflectance FTIR of stains on grit blasted metals

    SciTech Connect

    Powell, G.L.; Hallman, R.L. Jr.; Cox, R.L. [Oak Ridge Centers for Manufacturing Technologies, TN (United States)

    1997-08-09

    Diffuse reflectance mid-infrared Fourier transform (DRIFT) spectroscopy has been applied to the detection of oil contamination on grit-blasted metals. The object of this application is to detect and discriminate between silicone and hydrocarbon oil contamination at levels approaching 10 mg/m{sup 2}. A portable FTIR spectrometer with dedicated diffuse reflectance optics was developed for this purpose. Using translation devices positioned by instructions from the spectrometer operating system, images of macroscopic substrates were produced with millimeter spatial resolution. The pixels that comprise an image are each a full mid-infrared spectrum with excellent signal-to-noise, each determined as individual files and uniquely saved to disc. Reduced spectra amplitudes, based on peak height, area, or other chemometric techniques, mapped as a function of the spatial coordinates of the pixel are used to display the image. This paper demonstrates the application of the technique to the analysis of stains on grit-blasted metals, including the calibration of the method, the inspection of substrates, and the migration of oil contamination.

  14. Grit

    NSDL National Science Digital Library

    2012-01-01

    This page from Character Lab presents information about the trait of grit and its impact in the classroom. The reader learns what grit is, what it looks like, why it is important, and how to develop it in learners. Included is a 5-minute video of Dr. Angela Duckworth discussing the importance of grit in students as well as links to further resources about the topic.

  15. Acid etching and plasma sterilization fail to improve osseointegration of grit blasted titanium implants.

    PubMed

    Saksř, Mikkel; Jakobsen, Stig S; Saksř, Henrik; Baas, Jřrgen; Jakobsen, Thomas; Sřballe, Kjeld

    2012-01-01

    Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation was evaluated by implant osseointegration and biomechanical fixation.The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant tissue density) and mechanical push-out testing after four weeks observation time.Neither acid etching nor plasma sterilization of the grit blasted implants enhanced osseointegration or mechanical fixation in this press-fit canine implant model in a statistically significant manner. PMID:22962567

  16. Acid Etching and Plasma Sterilization Fail to Improve Osseointegration of Grit Blasted Titanium Implants

    PubMed Central

    Saksř, Mikkel; Jakobsen, Stig S; Saksř, Henrik; Baas, Jřrgen; Jakobsen, Thomas; Sřballe, Kjeld

    2012-01-01

    Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation was evaluated by implant osseointegration and biomechanical fixation. The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant tissue density) and mechanical push-out testing after four weeks observation time. Neither acid etching nor plasma sterilization of the grit blasted implants enhanced osseointegration or mechanical fixation in this press-fit canine implant model in a statistically significant manner. PMID:22962567

  17. A scientific view of the productivity of abrasive blasting nozzles

    Microsoft Academic Search

    G. S. Settles; S. Garg

    1996-01-01

    flow. So does a blasting nozzle, although the diamonds are seldom visible to the naked eye. Micrometer-sized alumina particles are accelerated through the nozzles of the shuttle's solid rocket boosters (Ref 1), just as abrasive particles are accelerated through a blasting nozzle. (Actually, it is easier to analyze the shuttle booster problem because the particles are so small.) This article

  18. Analysis of Abrasive Blasting of DOP-26 Iridium Alloy

    SciTech Connect

    Ohriner, Evan Keith [ORNL; Zhang, Wei [ORNL; Ulrich, George B [ORNL

    2012-01-01

    The effects of abrasive blasting on the surface geometry and microstructure of DOP-26 iridium alloy (Ir-0.3% W-0.006% Th 0.005% Al) have been investigated. Abrasive blasting has been used to control emissivity of components operating at elevated temperature. The effects of abrasive blasting conditions on surface morphology were investigated both experimentally and by numerical modeling. The simplified model, based on finite element analysis of a single angular particle impacting on Ir alloy disk, calculates the surface deformation and residual strain distribution. The experimental results and modeling results both indicate that the surface geometry is not sensitive to the abrasive blast process conditions of nozzle pressure and standoff distance considered in this study. On the other hand, the modeling results suggest that the angularity of the abrasive particle has an important role in determining surface geometry, which in turn, affects the emissivity. Abrasive blasting causes localized surface strains and localized recrystallization, but it does not affect grain size following extended exposure at elevated temperature. The dependence of emissivity of the DOP-26 alloy on mean surface slope follows a similar trend to that reported for pure iridium.

  19. The effect of grit blasting on the oxidation behavior of a platinum-modified nickel-aluminide coating

    Microsoft Academic Search

    V. K. Tolpygo; D. R. Clarke; K. S. Murphy

    2001-01-01

    The surface of platinum-modified nickel-aluminide bond coats on superalloys is usually roughened by grit blasting prior to\\u000a deposition of thermal barrier coatings (TBCs). Analysis of the grit-blasted surface by secondary ion mass spectrometry (SIMS)\\u000a reveals that this pretreatment leads to contamination of the bond coat by various impurities, in particular, the alkali and\\u000a alkaline-earth metals and titanium. These impurities then

  20. Grit blast/silane surface treatment for structural bonding of aluminum

    SciTech Connect

    Mazza, J.J. [USAF Wright Laboratory Materials Directorate, Wright-Patterson Air Force Base, OH (United States)

    1996-12-31

    The use of silane coupling agents as prebond surface treatments for aluminum aircraft structure is not new. The Royal Australian Air Force (RAAF) has extensively used a silane surface preparation in applications of bonded composite repairs to aircraft structure. Recently, the USAF has begun to employ bonded composite repair technology as a means to extend the service lives of its aging aircraft. A grit blast/silane surface treatment optimized by the USAF Wright Laboratory Materials Directorate (ML) has been used in many of the applications, most notably on the C-141 aircraft. The ML process is desirable for many USAF applications since it does not contain acids which could harm aircraft structure, and it is similar to the Australian technique which has claimed years of success. The ML grit blast/silane surface treatment was inspired by the Australian process which was developed by the Aeronautical and Maritime Research Laboratory (AMRL). The Australians generated considerable interest in their process, however, several key organizations were unable to duplicate the performance cited by AMRL. Some questioned the viability of the Australian silane process. To resolve this question for Warner Robins Air Logistics Center (WR-ALC) personnel, as well as continue ML`s ongoing silane work, a program was run to understand the AMRL surface prep. This led to the development of the ML grit blast/silane process and its on-aircraft applications.

  1. Control technology for crystalline silica exposures in construction: wet abrasive blasting.

    PubMed

    Golla, Vijay; Heitbrink, William

    2004-03-01

    This study was designed to document the effect that wet abrasive blasting has on reducing worker exposure to crystalline silica, which has been associated with silicosis and premature death. In this study, worker exposure to respirable crystalline silica was monitored during wet abrasive blasting on the exterior walls of a parking garage to remove surface concrete and expose the underlying aggregate. In this process a wet sand mix comprised of 80% dry sand and 20% water was used. Sampling and analysis revealed that the geometric mean respirable quartz concentration was 0.2 mg/m(3) for workers conducting abrasive blasting and 0.06 mg/m(3) for helpers. When abrasive blasting was conducted in areas that apparently had reduced natural ventilation, dust exposures appeared to increase. When compared with other published data, this case study suggests that wet abrasive blasting causes less exposure to crystalline silica than dry abrasive blasting. PMID:15204868

  2. Surface assessment and modification of concrete using abrasive blasting

    NASA Astrophysics Data System (ADS)

    Millman, Lauren R.

    Composite systems are applied to concrete substrates to strengthen and extend the service life. Successful restoration or rehabilitation requires surface preparation prior to the application of the overlay. Surface coatings, waterproofing systems, and other external surface applications also require surface preparation prior to application. Abrasive blast media is often used to clean and uniformly roughen the substrate. The appropriate surface roughness is necessary to facilitate a strong bond between the existing substrate and overlay. Thus, surface modification using abrasive blast media (sand and dry ice), their respective environmental effects, surface roughness characterization prior to and after blasting, and the adhesion between the substrate and overlay are the focus of this dissertation. This dissertation is comprised of an introduction, a literature review, and four chapters, the first of which addresses the environmental effects due to abrasive blasting using sand, water, and dry ice. The assessment considered four response variables: carbon dioxide (CO2) emissions, fuel and energy consumption, and project duration. The results indicated that for sand blasting and water jetting, the primary factor contributing to environmental detriment was CO22 emissions from vehicular traffic near the construction site. The second chapter is an analysis of the International Concrete Repair Institute's (ICRI) concrete surface profiles (CSPs) using 3-D optical profilometry. The primary objective was to evaluate the suitability of approximating the 3-D surface (areal) parameters with those extracted from 2-D (linear) profiles. Four profile directions were considered: two diagonals, and lines parallel and transverse to the longitudinal direction of the mold. For any CSP mold, the estimation of the 3-D surface roughness using a 2-D linear profile resulted in underestimation and overestimation errors exceeding 50%, demonstrating the inadequacy of 2-D linear profiles to approximate the 3-D concrete surface profiles. The errors were reduced when a weighted average of the four linear profiles approximated the corresponding 3-D parameter. The following chapter considers the parametric and sensitivity of concrete surface topography measurements. The weighted average of the four 2-D profiles consistently resulted in underestimation of the corresponding 3-D parameters: the dispersion of surface elevations (Sq) and the roughness (Sa). Results indicated the 3-D parameter, Sq, had the least sensitivity to data point reduction. The final chapter investigated surface modification using dry ice and sand blasting. The overall objective was to evaluate the change in the 3-D surface roughness (Sa) following blasting as functions of mix design and as induced by freeze-thaw cycling, and to compare the results obtained using dry ice with those obtained using sand as the blasting media. In general, sand blasting produced larger changes in Sa compared to dry ice blasting for the concrete mix designs considered. The primary mechanism responsible for altering the surface topography of the concrete was the scaling of the superficial cement paste layer on the exposed surface, which was due to freeze-thaw cycling. The largest relative change in roughness following blasting occurred in the control samples, which had not undergone freeze-thaw cycling.

  3. Shot peening, grit blasting make pipe steels more resistant to stress-corrosion cracking

    SciTech Connect

    Barlo, T.J.; Fessler, R.R.

    1981-11-16

    Shot peening or grit blasting to one of several controlled conditions is an effective means of increasing the resistance of pipeline steels to stress-corrosion cracking (SCC). Though the principal benefit is to increase the threshold stress for SCC, mill-scale removal and a good coating anchor pattern provide added benefits. Five principal factors influence the initiation and growth rate of stress-corrosion cracks in buried pipelines. These factors are susceptibility of the steel, stress level and strain rate, chemical environment in contact with the steel surface, electrochemical potential established on the steel surface, and temperature of the steel and environment system. These 5 factors are strongly interrelated in rather complex ways, but it is recognized that, for stress-corrosion cracks to grow, all 5 factors must be present concurrently and at appropriate levels. As a result, stress-corrosion cracking can be stopped or reduced by appropriately modifying any one of these 5 factors.

  4. Grit blasting of Ti–6Al–4V alloy: Optimization and its effect on adhesion strength of plasma-sprayed hydroxyapatite coatings

    Microsoft Academic Search

    Z. Mohammadi; A. A. Ziaei-Moayyed; A. Sheikh-Mehdi Mesgar

    2007-01-01

    The effect of grit blasting parameters on the surface roughness of Ti–6Al–4V alloy as the substrate for plasma-sprayed hydroxyapatite (HA) coatings was examined using the factorial and Taguchi designs of experiments. In this study, two grit materials (Al2O3 and SiO2) each at two sizes, and two types of blasting systems (pressure and suction) were used. An equivalent surface roughness of

  5. Exposure to crystalline silica in abrasive blasting operations where silica and non-silica abrasives are used.

    PubMed

    Radnoff, Diane L; Kutz, Michelle K

    2014-01-01

    Exposure to respirable crystalline silica is a hazard common to many industries in Alberta but particularly so in abrasive blasting. Alberta occupational health and safety legislation requires the consideration of silica substitutes when conducting abrasive blasting, where reasonably practicable. In this study, exposure to crystalline silica during abrasive blasting was evaluated when both silica and non-silica products were used. The crystalline silica content of non-silica abrasives was also measured. The facilities evaluated were preparing metal products for the application of coatings, so the substrate should not have had a significant contribution to worker exposure to crystalline silica. The occupational sampling results indicate that two-thirds of the workers assessed were potentially over-exposed to respirable crystalline silica. About one-third of the measurements over the exposure limit were at the work sites using silica substitutes at the time of the assessment. The use of the silica substitute, by itself, did not appear to have a large effect on the mean airborne exposure levels. There are a number of factors that may contribute to over-exposures, including the isolation of the blasting area, housekeeping, and inappropriate use of respiratory protective equipment. However, the non-silica abrasives themselves also contain silica. Bulk analysis results for non-silica abrasives commercially available in Alberta indicate that many contain crystalline silica above the legislated disclosure limit of 0.1% weight of silica per weight of product (w/w) and this information may not be accurately disclosed on the material safety data sheet for the product. The employer may still have to evaluate the potential for exposure to crystalline silica at their work site, even when silica substitutes are used. Limited tests on recycled non-silica abrasive indicated that the silica content had increased. Further study is required to evaluate the impact of product recycling on crystalline silica content for non-silica abrasives. Measurement of blaster exposure was challenging in this study as the blasters evaluated conducted this task intermittently throughout the work shift, frequently removing their blasting helmets. In spite of the challenges in accurately measuring blaster exposure, the measurements were still, for the most part, over the 8-h OEL. Further work is required to develop more effective sampling strategies to evaluate blaster exposure over the full work shift when task-based monitoring is not practical. PMID:24353009

  6. Application of Abrasive-Waterjets for Machining Fatigue-Critical Aircraft Aluminum Parts

    SciTech Connect

    Liu, H. T.; Hovanski, Yuri; Dahl, Michael E.; Zeng, J.

    2010-08-19

    The effects of dry-grid blasting of AWJ-machined dog-bone specimens of aircraft aluminum with aluminum oxide abrasives were investigated in terms of enhancement in fatigue performance and mitigating concerns of abrasive contamination. Results obtained from fatigue tests have indicated that the surface roughness, Ra, of AWJ-induced striations is inversely proportional to the fatigue life. The fatigue life of AWJ-machined and baseline specimens, excluding those processed with dry-grit blasting, decreases with the increase in Ra. Removal of the striations with dry-grit blasting until they disappear visually only reduces Ra from 3.5 to 2.4 ?m and is still higher than that of the conventionally machined edges with Ra = 1.6 ?m. From the surface roughness point of view, the fatigue life of the dry-grit blasted specimens should not have exceeded that of the baseline counterparts. Yet the dry-grit blasting process has extended the fatigue life of the AWJ-machined specimens and the baseline counterparts by more than four and three times, respectively. The extraordinary boost in the fatigue performance is believed to be attributed to the induction of residual compressive stresses by dry-grit blasting. Such a belief was subsequent confirmed quantitatively through measurements of residual compressive stresses. Dry-grid blasting can be carried out efficiently and cost effectively by stacking AWJ-machined parts together. The benefits gained from dry-grit blasting simply outweigh the marginal cost increase.

  7. Demonstration experience with an abrasive blasting technique for decontaminating concrete pads

    SciTech Connect

    Devgun, J.S. (Argonne National Lab., IL (USA)); Land, R.R. (Bechtel National, Inc., Oak Ridge, TN (USA)); Doane, R.W. (TMA/Eberline, Oak Ridge, TN (USA))

    1990-01-01

    A demonstration was performed for decontaminating a radioactivity contaminated concrete pad with a portable abrasive blasting system. The system utilizes a rotating blast wheel that scours the concrete surface with metal abrasive. The metal abrasive, pulverized concrete dust, and contaminants rebound into a separator chamber. The reusable metal abrasive is recycled, and the pulverized media are removed to an integral dust collection system. The exhaust is HEPA filtered to minimize release of airborne contaminants. However, the technique had limited success in reducing contamination around the cracks and seams in the concrete where the higher activity levels of contamination were detected during the radiological survey before the cleanup. The technique can be successful and cost-effective in decontaminating large areas of low contamination; however, careful characterization and planning are necessary. 3 refs., 3 figs., 1 tabs.

  8. Adhesion Strength of Thermal Barrier Coatings with Thermal-Sprayed Bondcoat Treated by Compound Method of High-Current Pulsed Electron Beam and Grit Blasting

    NASA Astrophysics Data System (ADS)

    Cai, Jie; Guan, Qingfeng; Lv, Peng; Hou, Xiuli; Wang, Zhiping; Han, Zhiyong

    2015-06-01

    Microstructural characteristics and adhesion properties of air plasma spraying, thermal barrier coatings (TBCs) having thermally sprayed bond coats treated by high-current pulsed electron beam (HCPEB) irradiation, and a combination treatment of HCPEB and grit blasting were investigated. Microstructure observations revealed that the original coarse surface of thermally sprayed bond coat was significantly changed to interconnected bulged nodules with a compact appearance after HCPEB irradiation. With further grit blasting treatment, these series of bulged nodules appeared with successive and uniform jagged edges. Surface roughness of the bond coat after compound treatment became higher due to these bulged nodules with jagged edges, which was conducive to ceramic deposition. The results of the tensile test revealed that the adhesion strength of thermally sprayed TBCs with the bond coats conducted by a compound treatment was obviously increased. The combination treatment of HCPEB and grit blasting improved the interfacial bonding strength as well as the interfacial homogeneity.

  9. Liquid abrasive grit blasting literature search and decontamination scoping tests report

    Microsoft Academic Search

    1993-01-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP) have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical\\/water flushes and steam jet cleaning.

  10. Grit blasting of medical stainless steel: implications on its corrosion behavior, ion release and biocompatibility.

    PubMed

    Galván, J C; Saldańa, L; Multigner, M; Calzado-Martín, A; Larrea, M; Serra, C; Vilaboa, N; González-Carrasco, J L

    2012-03-01

    This study reports on the biocompatibility of 316 LVM steel blasted with small and rounded ZrO(2) particles or larger and angular shaped Al(2)O(3) particles. The effect of blasting on the in vitro corrosion behavior and the associated ion release is also considered. Surface of Al(2)O(3) blasted samples was rougher than that of ZrO(2) blasted samples, which was also manifested by a higher surface area. Compared to the polished alloy, blasted steels exhibited a lower corrosion resistance at the earlier stages of immersion, particularly when using Al(2)O(3) particles. With increasing immersion time, blasted samples experienced an improvement of the corrosion resistance, achieving impedance values typical of passive alloys. Blasting of the alloy led to an increase in Fe release and the leaching of Ni, Mn, Cr and Mo. On all surfaces, ion release is higher during the first 24 h exposure and tends to decrease during the subsequent exposure time. Despite the lower corrosion resistance and higher amount of ions released, blasted alloys exhibit a good biocompatibility, as demonstrated by culturing osteoblastic cells that attached and grew on the surfaces. PMID:22271277

  11. Enhanced osseointegration of grit-blasted, NaOH-treated and electrochemically hydroxyapatite-coated Ti–6Al–4V implants in rabbits

    Microsoft Academic Search

    Dror Lakstein; William Kopelovitch; Zahava Barkay; Medlej Bahaa; David Hendel; Noam Eliaz

    2009-01-01

    Osseointegration, in terms of the bone apposition ratio (BAR) and the new bone area (NBA), was measured by backscattered electron imaging. The results were compared for four implant types: grit-blasted and NaOH-treated Ti–6Al–4V (Uncoated-NaOH), electrodeposited with hydroxyapatite without alkali treatment (ED-HAp), electrodeposited with hydroxyapatite after alkali treatment (NaOH-ED-HAp), and plasma sprayed with hydroxyapatite (PS-HAp). No heat treatment was done after

  12. The effect of abrasive blasting on the strength of a joint between dental porcelain and metal base.

    PubMed

    Pietnicki, Krzysztof; Wo?owiec, Emilia; Klimek, Leszek

    2014-01-01

    This paper presents the effect of selected parameters of abrasive blasting on the strength of a joint between dental porcelain and metal base. Experiments were conducted for different grain sizes of abrasive material and different blasting angles, with a constant blasting pressure. InLine dental porcelain was fused on samples of cobalt-chromium alloy following abrasive blasting; they were subsequently subjected to shearing forces on a testing machine. The fractures were observed under an electron scanning microscope in order to determine the character and course of fracturing. Strength tests showed that the grain size of abrasive material was a parameter with the greatest effect on the strength. The best effects were achieved for samples subjected to abrasive blasting with material with grain size of 110 ?m. No statistically significant differences were found for the strength of samples worked at different angles. The results of the fractographic examinations have shown that in all the samples, fracturing occurred mainly along the porcelain-metal boundary, with few cases of fracturing through porcelain. PMID:24708248

  13. Abrasives

    Microsoft Academic Search

    Masakatsu Asami; Michael Santorelli

    2010-01-01

    \\u000a The historical development of the abrasives industry is noteworthy considering its evolution from a rudimentary beginning\\u000a to a relatively mature industry. Presently, hardly a material exists that has not been exposed to a grinding operation. It\\u000a can be stated without exaggeration that the abrasives industry represents a basic building block for all other branches of\\u000a industry.\\u000a \\u000a \\u000a There are two basic

  14. Effect of erbium-doped: yttrium, aluminium and garnet laser irradiation on the surface microstructure and roughness of sand-blasted, large grit, acid-etched implants

    PubMed Central

    Lee, Ji-Hun; Kwon, Young-Hyuk; Herr, Yeek; Shin, Seung-Il

    2011-01-01

    Purpose The present study was performed to evaluate the effect of erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser irradiation on sand-blasted, large grit, acid-etched (SLA) implant surface microstructure according to varying energy levels and application times of the laser. Methods The implant surface was irradiated by the Er:YAG laser under combined conditions of 100, 140, or 180 mJ/pulse and an application time of 1 minute, 1.5 minutes, or 2 minutes. Scanning electron microscopy (SEM) was used to examine the surface roughness of the specimens. Results All experimental conditions of Er:YAG laser irradiation, except the power setting of 100 mJ/pulse for 1 minute and 1.5 minutes, led to an alteration in the implant surface. SEM evaluation showed a decrease in the surface roughness of the implants. However, the difference was not statistically significant. Alterations of implant surfaces included meltdown and flattening. More extensive alterations were present with increasing laser energy and application time. Conclusions To ensure no damage to their surfaces, it is recommended that SLA implants be irradiated with an Er:YAG laser below 100 mJ/pulse and 1.5 minutes for detoxifying the implant surfaces. PMID:21811689

  15. Adult stem cells properties in terms of commitment, aging and biological safety of grit-blasted and Acid-etched ti dental implants surfaces.

    PubMed

    Gardin, Chiara; Ferroni, Letizia; Bressan, Eriberto; Calvo-Guirado, José L; Degidi, Marco; Piattelli, Adriano; Zavan, Barbara

    2014-01-01

    Titanium (Ti) is one of the most widely used biomaterials for manufacturing dental implants. The implant surface properties strongly influence osseointegration. The aim of the present study was to in vitro investigate the characteristics of Ti dental implants in terms of mutagenicity, hemocompatibility, biocompatibility, osteoinductivity and biological safety. The Ames test was used to test the mutagenicity of the Ti dental implants, and the hemolysis assay for evaluating their hemocompatibility. Human adipose - derived stem cells (ADSCs) were then seeded onto these implants in order to evaluate their cytotoxicity. Gene expression analyzing with real-time PCR was carried out to investigate the osteoinductivity of the biomaterials. Finally, the genetic stability of the cells cultured onto dental implants was determined by karyotyping. Our results demonstrated that Ti dental implants are not mutagenic, do not cause hemolysis, and are biocompatible. The MTT assay revealed that ADSCs, seeded on Ti dental implants, proliferate up to 30 days in culture. Moreover, ADSCs loaded on Ti dental implants show a substantial expression of some osteoblast specific markers, such as COL1A1, OPN, ALPL, and RUNX2, as well as chromosomal stability after 30 days of culture in a medium without osteogenic factors. In conclusion, the grit-blasted and acid-etched treatment seems to favor the adhesion and proliferation of ADSCs and improve the osteoinductivity of Ti dental implant surfaces. PMID:25635249

  16. Adult Stem Cells Properties in Terms of Commitment, Aging and Biological Safety of Grit-Blasted and Acid-Etched Ti Dental Implants Surfaces

    PubMed Central

    Gardin, Chiara; Ferroni, Letizia; Bressan, Eriberto; Calvo - Guirado, José L.; Degidi, Marco; Piattelli, Adriano; Zavan, Barbara

    2014-01-01

    Titanium (Ti) is one of the most widely used biomaterials for manufacturing dental implants. The implant surface properties strongly influence osseointegration. The aim of the present study was to in vitro investigate the characteristics of Ti dental implants in terms of mutagenicity, hemocompatibility, biocompatibility, osteoinductivity and biological safety. The Ames test was used to test the mutagenicity of the Ti dental implants, and the hemolysis assay for evaluating their hemocompatibility. Human adipose - derived stem cells (ADSCs) were then seeded onto these implants in order to evaluate their cytotoxicity. Gene expression analyzing with real-time PCR was carried out to investigate the osteoinductivity of the biomaterials. Finally, the genetic stability of the cells cultured onto dental implants was determined by karyotyping. Our results demonstrated that Ti dental implants are not mutagenic, do not cause hemolysis, and are biocompatible. The MTT assay revealed that ADSCs, seeded on Ti dental implants, proliferate up to 30 days in culture. Moreover, ADSCs loaded on Ti dental implants show a substantial expression of some osteoblast specific markers, such as COL1A1, OPN, ALPL, and RUNX2, as well as chromosomal stability after 30 days of culture in a medium without osteogenic factors. In conclusion, the grit-blasted and acid-etched treatment seems to favor the adhesion and proliferation of ADSCs and improve the osteoinductivity of Ti dental implant surfaces. PMID:25635249

  17. Machining of Aircraft Titanium with Abrasive-Waterjets for Fatigue Critical Applications

    SciTech Connect

    Liu, H. T.; Hovanski, Yuri; Dahl, Michael E.

    2012-02-01

    Laboratory tests were conducted to determine the fatigue performance of abrasive-waterjet- (AWJ-) machined aircraft titanium. Dog-bone specimens machined with AWJs were prepared and tested with and without sanding and dry-grit blasting with Al2O3 as secondary processes. The secondary processes were applied to remove the visual appearance of AWJ-generated striations and to clean up the garnet embedment. The fatigue performance of AWJ-machined specimens was compared with baseline specimens machined with CNC milling. Fatigue test results of the titanium specimens not only confirmed our previous findings in aluminum dog-bone specimens but in comparison also further enhanced the fatigue performance of the titanium. In addition, titanium is known to be difficult to cut, particularly for thick parts, however AWJs cut the material 34% faster han stainless steel. AWJ cutting and dry-grit blasting are shown to be a preferred ombination for processing aircraft titanium that is fatigue critical.

  18. Monitoring and Testing the Parts Cleaning Stations, Abrasive Blasting Cabinets, and Paint Booths

    NASA Technical Reports Server (NTRS)

    Jordan, Tracee M.

    2004-01-01

    I have the opportunity to work in the Environmental Management Office (EMO) this summer. One of the EMO's tasks is to make sure the Environmental Management System is implemented to the entire Glenn Research Center (GRC). The Environmental Management System (EMS) is a policy or plan that is oriented toward minimizing an organization's impact to the environment. Our EMS includes the reduction of solid waste regeneration and the reduction of hazardous material use, waste, and pollution. With the Waste Management Team's (WMT) help, the EMS can be implemented throughout the NASA Glenn Research Center. The WMT is responsible for the disposal and managing of waste throughout the GRC. They are also responsible for the management of all chemical waste in the facility. My responsibility is to support the waste management team by performing an inventory on parts cleaning stations, abrasive cabinets, and paint booths through out the entire facility. These booths/stations are used throughout the center and they need to be monitored and tested for hazardous waste and material. My job is to visit each of these booths/stations, take samples of the waste, and analyze the samples.

  19. Development and validation of the short grit scale (grit-s).

    PubMed

    Duckworth, Angela Lee; Quinn, Patrick D

    2009-03-01

    In this article, we introduce brief self-report and informant-report versions of the Grit Scale, which measures trait-level perseverance and passion for long-term goals. The Short Grit Scale (Grit-S) retains the 2-factor structure of the original Grit Scale (Duckworth, Peterson, Matthews, & Kelly, 2007) with 4 fewer items and improved psychometric properties. We present evidence for the Grit-S's internal consistency, test-retest stability, consensual validity with informant-report versions, and predictive validity. Among adults, the Grit-S was associated with educational attainment and fewer career changes. Among adolescents, the Grit-S longitudinally predicted GPA and, inversely, hours watching television. Among cadets at the United States Military Academy, West Point, the Grit-S predicted retention. Among Scripps National Spelling Bee competitors, the Grit-S predicted final round attained, a relationship mediated by lifetime spelling practice. PMID:19205937

  20. Potential Use of Abrasive Air-Propelled Agricultural Residues for Weed Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new postemergence weed control tactic is proposed for organic production systems that results in plant abrasion and death upon assault from abrasive grits propelled by compressed air. Grit derived from granulated walnut shells was delivered by a sand blaster at 517 kPa at distances of 30 to 60 cm ...

  1. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, E.L.

    1984-11-29

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  2. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, Edward L. (Santa Fe, NM)

    1985-01-01

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  3. Abrasive tip treatment for use on compressor blades

    NASA Technical Reports Server (NTRS)

    Pedersen, H. C.

    1984-01-01

    A co-spray process was used which simultaneously but separately introduces abrasive grits and metal matrix powder into the plasma stream and entraps the abrasive grits within a molten matrix to form an abrasive coating as the matrix material solidifies on test specimen surfaces. Spray trials were conducted to optimize spray parameter settings for the various matrix/grit combinations before actual spraying of the test specimens. Rub, erosion, and bond adhesion tests were conducted on the coated specimens in the as-sprayed condition as well as on coated specimens that were aged for 100 hours at a temperature of 866K (1100 F). Microscopic examinations were performed to determine the coating abrasive-particle content, the size and shape of the adhesive particles in the coating, and the extent of compositional or morphological changes resulting from the aging process. A nickel chromium/aluminum composite with No. 150 size (0.002 to 0.005 inch) silicon carbide grits was selected as the best matrix/abrasive combination of the candidates surveyed for coating compressor blade tips.

  4. Dry Flowing Abrasive Decontamination Technique for Pipe Systems with Swirling Air Flow

    Microsoft Academic Search

    Yutaka Kameo; Mikio Nakashima; Takakuni Hirabayashi

    2003-01-01

    A dry abrasive decontamination method was developed for removing radioactive corrosion products from surfaces of coolant pipe systems in decommissioning of a nuclear power plant. Erosion behavior of inside surfaces of stainless and carbon steel pipes by a swirling air flow containing alumina or cast-iron grit abrasive was studied. Erosion depths of the test pipes were approximately proportional to an

  5. Abrasion of flat rotating shapes

    NASA Astrophysics Data System (ADS)

    Roth, A. E.; Marques, C. M.; Durian, D. J.

    2011-03-01

    We report on the erosion of flat linoleum “pebbles” under steady rotation in a slurry of abrasive grit. To quantify shape as a function of time, we develop a general method in which the pebble is photographed from multiple angles with respect to the grid of pixels with a digital camera. This reduces digitization noise and allows the local curvature of the contour to be computed with a controllable degree of uncertainty. Several shape descriptors are then employed to follow the evolution of different initial shapes toward a circle, where abrasion halts. The results are in good quantitative agreement with a simple model, where we propose that points along the contour move radially inward in proportion to the product of the radius and the derivative of radius with respect to angle.

  6. Potential of Air-Propelled Abrasives for Selective Weed Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel forms of selective weed control are needed by many types of growers, but especially organic growers who are restricted from using synthetic herbicides. Abrasive grit made from corn cobs was expelled from a sand blaster at 517 kPa pressure and aimed at seedlings of common lambsquarters and corn...

  7. Air Abrasion

    MedlinePLUS

    ... cracks and discolored teeth, to prepare teeth for bonding procedures, such as sealants, and for various other procedures. Air abrasion works ... remove stains and spots; repair old fillings and sealants; and repair broken crowns and bridges. Your general ...

  8. Material response to particle impact during abrasive jet machining of alumina ceramics

    Microsoft Academic Search

    Manabu Wakuda; Yukihiko Yamauchi; Shuzo Kanzaki

    2003-01-01

    Abrasive jet machining (AJM), a specialized form of shot blasting, attracts much attention as a hopeful micro-machining method for hard, brittle materials such as structural ceramics. The present paper attempts to identify the material response of alumina ceramics to the abrasive particle impact in the AJM process. Three kinds of commercial abrasive particles were utilized to dimple the sintered alumina

  9. Abrasion and deformed layer formation of manganese-zinc ferrite in sliding contact with lapping tapes

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.; Tanaka, K.

    1986-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and the deformed layers produced in single-crystal Mn-Zn ferrite simulated heads during contact with lapping tapes. The crystaline state of the head is changed drastically during the abrasion process. Crystalline states ranging from nearly amorphous to highly textured polycrystalline can be produced on the wear surface of a single-crystal Mn-Zn ferrite head. The total thickness of the deformed layer was approximately 0.8 microns. This thickness increased as the load and abrasive grit size increased. The anisotropic wear of the ferrite was found to be inversely proportional to the hardness of the wear surface. The wear was lower in the order 211 111 10 0110. The wear of the ferrite increased markedly with an increase in sliding velocity and abrasive grit size.

  10. The Effect of Abrasive Particle Size on the Wear Behaviour of Metal Matrix Composites

    NASA Astrophysics Data System (ADS)

    Sahin, Y.; Ozdin, K.

    2004-06-01

    The effect of abrasive particle size on the wear behavior of the SiC particle-reinforced aluminium composites produced by liquid metallurgy was investigated under different sizes of SiC grits at a fixed speed. The results show that the wear loss of composite was considerably lower than that of aluminium alloy. The wear loss increased linearly with sliding distance for both materials, but indicating a considerable difference. It increased with increasing SiC abrasive particles. Moreover, SEM examination indicates that abrasive wear observed for the matrix alloy. The depth of wear grooves decreased with decreasing the abrasive particle size and load. For the composites, wear surfaces were found to be a quite smooth indicating that no abrasive grooves appeared.

  11. Development of a two-body wet abrasion test method with attention to the effects of reused abradant

    SciTech Connect

    Blau, Peter Julian [ORNL; Dehoff, Ryan R [ORNL

    2012-01-01

    Abrasive wear is among the most common and costliest causes for material wastage, and it occurs in many forms. A simple method has been developed to quantify the response of metals and alloys to two-body wet abrasion. A metallographic polishing machine was modified to create a disk-on-flat sliding test rig. Adhesive-backed SiC grinding papers were used under fixed load and speed to rank the abrasive wear of seven alloy steels, some of which are candidates for drill cones for geothermal drilling. Standardized two-body abrasion tests, like those described in ASTM G132, feed unused abrasive into the contact; however, the current work investigated whether useful rankings could still be obtained with a simpler testing configuration in which specimens repeatedly slide on the same wear path under water-lubricated conditions. Tests using abrasive grit sizes of 120 and 180 resulted in the same relative ranking of the alloys although the coarser grit produced more total wear. Wear decreased when the same abrasive disk was re-used for up to five runs, but the relative rankings of the steels remained the same. This procedure was presented to ASTM Committee G2 on Wear and Erosion as a potential standard test for wet two-body abrasive wear.

  12. The mechanical value of grit for bobwhite quail

    USGS Publications Warehouse

    Nestler, R.B.

    1946-01-01

    An investigation on the need of grit as a grinding agent in the digestive processes of bobwhite quail was conducted with 1,372 pen-raised birds at the Patuxent Research Refuge, Bowie, Maryland. Some of the stock was reared, maintained through winter, and bred without access to any grit, although the diet after the tenth week consisted of whole seeds......As to survival, weight, and efficiency of feed consumption, the birds without grit during their period of growth equalled those with access to grit. Such birds, when continued on a gritless regimen during the winter, survived and maintained their weight as successfully as birds on grit. There were no gizzard lesions, and the digestion of whole seeds was satisfactory. Subsequent health and reproduction were unaffected by the absence of grit......The quail reared with access to grit retained an appreciable supply of grit in their gizzards for five months after being deprived of it.

  13. Avian Digestive Tract Simulation To Study the Effect of Grit

    E-print Network

    Green, Andy J.

    wheat seed). Dissolved Pb levels in simulated gizzards were consistently higher in the presence supplementation with clean grit may promote reduced shot ingestion in susceptible species. The amount of grit

  14. Machining of Aircraft Titanium with Abrasive-Waterjets for Fatigue Critical Applications

    SciTech Connect

    Liu, H. T.; Hovanski, Yuri; Dahl, Michael E.

    2010-10-04

    Laboratory tests were conducted to determine the fatigue performance of AWJ-machined aircraft titanium. Dog-bone specimens machined with AWJs were prepared and tested with and without sanding and dry-grit blasting with Al2O3 as secondary processes. The secondary processes were applied to remove the visual appearance of AWJ-generated striations and to clean up the garnet embedment. The fatigue performance of AWJ-machined specimens was compared with baseline specimens machined with CNC milling. Fatigue test results not only confirmed the findings of the aluminum dog-bone specimens but also further enhance the fatigue performance. In addition, titanium is known to be notoriously difficult to cut with contact tools while AWJs cut it 34% faster than stainless steel. AWJ cutting and dry-grit blasting are shown to be a preferred combination for processing aircraft titanium that is fatigue critical.

  15. Adhesive transfer to abrasive particles in abrasion testing

    Microsoft Academic Search

    Kenneth G. Budinski

    2011-01-01

    The definition of “abrasive wear” endorsed by the ASTM G2 Committee on Wear And Erosion is: “wear due to hard particles or hard protuberances forced against and moving along a solid surface”[1]. There are many models applied to abrasion that are based upon idealized cones (and other shapes) as an abrasive particle imposed on and moving in contact with a

  16. Valve for abrasive material

    DOEpatents

    Gardner, Harold S. (Turtle Creek, PA)

    1982-01-01

    A ball valve assembly for controlling the flow of abrasive particulates including an enlarged section at the bore inlet and an enlarged section at the bore outlet. A refractory ceramic annular deflector is positioned in each of the enlarged sections, substantially extending the useful life of the valve.

  17. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  18. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M. (Leola, PA)

    1984-10-23

    A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  19. Diallel analysis of corn for special use as corn grits: determining the main genetic effects for corn gritting ability.

    PubMed

    Conrado, T V; Scapim, C A; Bignotto, L S; Pinto, R J B; Freitas, I L J; Amaral, A T; Pinheiro, A C

    2014-01-01

    Corn grits are used for various purposes such as flakes, snacks, livestock feed, hominy, extruded products, beer, etc. The grit size proportion varies according to the hybrid, and thus, once the use of the grits is linked to the particle size, determining the genetic effects is essential to develop hybrids for any specific use. For this purpose a complete diallel series of crosses, involving eight parents, was performed near Maringá, PR, Brazil. The objective of this study was to evaluate the general (GCA) and specific (SCA) combining abilities of 28 progeny for selection of hybrids for breeding programs and extraction of inbred lines for hybrid development. The response variables, such as plant height, ear insertion height, crop stand, grain yield, and grits, small grits and bran production, were gauged and appraised for each of the 28 progeny. The trait effects and GCA were significant for all response variables, while for SCA, only grain yield and crop stand showed significance (P < 0.05), according to Griffing (1955) analysis. A significant weak negative partial correlation was found between grain yield and grits conversion. In relation to the hybrid selection for breeding programs, the parent IAC Nelore was highly recommended for recurrent selection and the hybrids IPR 119 x HT 392 and IAC Nelore x HD 332 for the extraction of pure lines for hybrid development. PMID:25177935

  20. Abrasion protection in process piping

    SciTech Connect

    Accetta, J. [Abresist Corp., Urbana, IN (United States)

    1996-07-01

    Process piping often is subjected to failure from abrasion or a combination of abrasion and corrosion. Abrasion is a complex phenomenon, with many factors involved to varying degrees. Hard, mineral based alumina ceramic and basalt materials are used to provide protection against abrasion in many piping systems. Successful life extension examples are presented from many different industries. Lined piping components require special attention with regard to operating conditions as well as design and engineering considerations. Economic justification involves direct cost comparisons and avoided costs.

  1. Colliding Pressure, Peening Effect and Removing Rate Exerted on Substrate by Blasting

    NASA Astrophysics Data System (ADS)

    Kubohori, Toshifum; Ito, Toru; Inui, Yasuyuki

    Blasting is a substrate processing technique during which spherical or granular materials made of metal or ceramics are jetted against the surface of substrate using compressed air. Blasting causes a variety of effects to appear on the substrate because the blasting material collides at high speed on the surface of substrate. As causes of influences exerted on the substrate, colliding pressure or particle shapes of the blasting material are conceivable. Results of this investigation are summarized as follows. In the range of blasting distance h at 10 - 150 mm, the maximum colliding pressure Pmax became highest at h = 10 mm. Moreover, the blasting surface area increased with an increase of h. Pmax went up as the blasting pressure ? increased, and suddenly dropped with an increase of h. The colliding pressure P was hardly affected by the type and particle size of blasting material, but was greatly influenced by ? and h. The arc height H was larger with steel shot than with steel grit. Shot had greater influences than grit on work hardening. Under the peening effect by blasting, work hardening was induced and the fatigue strength ?f increased. The removal ratio of specimen are different in each particle size.

  2. Abrasion Work on 'Uchben'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1

    Researchers used the rover Spirit's rock abrasion tool to help them study a rock dubbed 'Uchben' in the 'Columbia Hills' of Mars. The tool ground into the rock, creating a shallow hole 4.5 centimeters (1.8 inches) in diameter in the central upper portion of this image. It also used wire bristles to brush a portion of the surface below and to the right of the hole. Spirit used its panoramic camera during the rover's 293rd martian day (Oct. 29, 2004) to take the frames combined into this approximately true-color image.

  3. Grit Particle Enhanced Non-Shock Ignition of Explosives

    NASA Astrophysics Data System (ADS)

    Browning, Richard V.; Peterson, Paul D.; Roemer, Edward L.; Scammon, Richard J.

    2004-07-01

    Grit particles are used in explosive sensitivity tests, such as the drop weight impact test and the drop skid test, as sensitizing agents. In this paper we examine characteristics of common natural and industrial grit particles. They are observed in a wide variety of sizes and shapes. The fine particles can easily migrate around a facility and potentially become embedded in explosive surfaces. To study the effects of grit particles on ignition behavior we identify a simple configuration of particles cutting or grooving adjacent metal surfaces. We then present a process for analyzing the ignition characteristics. Estimates of the effective flow and fracture strength of the metals and explosive composites, on a scale of 1 to 100 microns, are used in chip forming models to calculate chip temperatures. Ignition characteristics are studied using a reactive heat transfer model of individual chips, as cut by grit particles, and held against an explosive surface. The models indicate that very small particles can cause ignition of adjacent explosives given the temperatures resulting from the chip forming process. These simulations are summarized in terms of non-dimensional variables.

  4. GRITS --2010/06/11 Trends in High Performance

    E-print Network

    GRITS -- 2010/06/11 Trends in High Performance Computing, and their Impact on Astrophysical Data at LBNL Focused on computational challenges (simulation and data processing) relevant to cosmology (CMB coordinated CPU allocations for CMB telescopes (funded by NASA, NSF, etc). Involved in building software

  5. Robust Planning of Green Wireless Networks Grit Claen

    E-print Network

    Paris-Sud XI, Université de

    Robust Planning of Green Wireless Networks Grit Claßen RWTH Aachen University Lehrstuhl II f@umic.rwth-aachen.de Abstract--Current methods dealing with the energy efficient wireless network planning problem require a robust optimization model for the energy-efficient planning of wireless networks and apply cutting planes

  6. ORIGINAL PAPER Use of grit supplements by waterbirds: an experimental

    E-print Network

    Paris-Sud XI, Université de

    with food particles causes Pb poisoning in a large number of waterbirds, this being one of the main causes ingest Pb shot pellets as grit or inadvertently with food particles and thus suffer from Pb poisoning to reduce lead poisoning Monica Martinez-Haro & Andy J. Green & Pelayo Acevedo & Rafael Mateo Received: 17

  7. Abrasive wear of cemented carbides

    SciTech Connect

    Hawk, Jeffrey A.; Wilson, Rick D.

    2003-10-01

    Cemented carbides are used for a wide variety of applications where wear is a problem. Usually the wear of the cemented carbides is a combination of metal-to-metal and abrasion. Wear can occur at room or elevated temperatures. This research summarizes initial research to understand the abrasive wear of various cemented carbides (various grain sizes, carbide types, carbide grain sizes and binder compositions) in terms of absolute material removal rates and material removal mechanisms.

  8. Should we be gritting pavements to prevent pedestrian injuries?

    PubMed

    Atenstaedt, Rob; Rees, Michael

    2013-05-01

    Unintentional injuries are an important public health issue, and are a significant burden on health and social services, especially during the winter months. Dr Rob Atenstaedt, Consultant in Public Health Medicine, Public Health Wales & Honorary Senior Lecturer, Bangor University and Professor Michael Rees, University Director of Medical Development & Professor of Cardiovascular Studies, Bangor University look at the importance of pavement gritting in preventing injuries and falls in pedestrians. PMID:23657235

  9. Successive Reduction Dry Milling of Normal and Waxy Corn: Grain, Grit, and Flour Properties.

    PubMed

    Thakur, Sheetal; Kaur, Amritpal; Singh, Narpinder; Virdi, Amardeep Singh

    2015-06-01

    Dry milling of different corn types resulted in varied proportions of germ, pericarp, grit and flour. Grit and flour produced during different reduction stages varied in particle size and chemical constituents, hence applications in food industry. In this study, recovery of different fractions and variation in physicochemical and pasting properties of grit and flour fractions obtained during 3 successive reduction dry millings of 2 normal (African tall, HQPM1) and 1 waxy corn (IC 550353) were evaluated. Waxy corn grains had the highest L*, a*, b*, ash, fat, and protein content and the lowest weight. Waxy and African tall gave the highest recovery of germ and pericarp, respectively. Waxy corn showed lower grit and flour recovery as compared to normal corn. Flour fractions showed higher L* and lower a* and b* values than grit fractions. Particle size of grit and flour fractions ranged from 840 to 982 ?m and 330 to 409 ?m, respectively. Fractions with larger particle size showed lower L* value. The b* value showed positive correlation with yellow pigment content. Grit and flour from the 1st reduction stage showed higher ash and fat content. Protein content was correlated positively with ash content and negatively with L* value. Grit and flour fractions with higher protein content had lower pasting viscosities. Pasting viscosities were higher for flours than their corresponding grits. Protein profiling of grit and flour fractions from different stages showed quantitative and qualitative differences in medium (22, 28, and 35 kDa) and low molecular weight (16, 17, and 19 kDa) polypeptides and were related to grit and flour yield. PMID:25943010

  10. LTC 1073 vacuum blasting (concrete) human factors assessment -- Baseline (summary)

    SciTech Connect

    NONE

    1997-07-31

    The LTC 1073 Vacuum Blasting Machine uses a high capacity, direct pressure blasting system incorporating a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast head. A vacuum system removes dust and debris from the surfaces as it is blasted. After cleaning the surface, the abrasive, together with the rust or coating that was removed from the surface, is vacuumed into the machine through the suction hose. The dust separator contains angled steel collision pads, working with the force of gravity, to allow any reusable abrasive to fall back into the pressure vessel. The filters are manually back flushed to prevent clogging. After back flushing, dust is dumped from the dust chamber into the dust collection bag or drum by operation of the bellows valve. The safety and health evaluation during the testing demonstration focused on dust and noise exposure. Dust exposure was found to be minimal, but noise exposure was potentially significant. Further testing for each of these exposures is recommended because the outdoor environment where the testing demonstration took place may cause the results to be inapplicable to indoor settings. It is feasible that the dust and noise levels will be higher in an enclosed operating environment. Other safety and health issues found were ergonomics, heat stress, tripping hazards, lockout/tagout, and arm-hand vibration.

  11. Characterizing hydrocyclone performance for grit removal from wastewater treatment activated sludge plants

    Microsoft Academic Search

    Majdala Mansour-Geoffrion; Peter L. Dold; Daniel Lamarre; Alain Gadbois; Stéphane Déléris; Yves Comeau

    2010-01-01

    Typically, 15–45% of the mixed liquor (sludge) in biological wastewater treatment plants (WWTPs) consists of inorganic (fixed) suspended solids. A portion of these inorganic compounds is grit (sand) originating from the influent. Grit accumulation impacts WWTP design and operating costs as these unbiodegradable solids reduce the effective treatment capacity of the bioreactor and other unit operations that must be sized

  12. Prediction of the effect of fine grit on the MLVSS/MLSS ratio of activated sludge.

    PubMed

    Fan, Jianping; Ji, Fangying; Xu, Xiaoyi; Wang, Ying; Yan, Dachao; Xu, Xuan; Chen, Qingkong; Xiong, Jingzhong; He, Qiang

    2015-08-01

    This paper investigated the suspension properties of fine grit with different particle sizes in a bioreactor and developed a model to predict its effect on the ratio of mixed liquor volatile suspended solids to the mixed liquor suspended solids (MLVSS/MLSS) of activated sludge. The experimental results revealed that a smaller particle size corresponds to a larger suspension ratio, defined as the proportion of fine grit brought in by influent that is suspended in the activated sludge, and a smaller MLVSS/MLSS ratio. The model demonstrated that the effect of fine grit on the MLVSS/MLSS ratio is related to the fine grit concentration and chemical oxygen demand in influent and the observed sludge yield. However, fine grit has no influence on the activity of microorganisms. Wastewater treatment plants (WWTPs) can adjust MLSS based on the MLVSS/MLSS ratio to ensure the stability of MLVSS, which can achieve the stable operation of WWTPs. PMID:25919937

  13. 9 CFR 311.14 - Abrasions, bruises, abscesses, pus, etc.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Abrasions, bruises, abscesses, pus, etc...CARCASSES AND PARTS § 311.14 Abrasions, bruises, abscesses, pus, etc. All slight, well-limited abrasions on the tongue and inner surface...

  14. Rheological quality of pearl millet porridge as affected by grits size.

    PubMed

    Yadav, Deep N; Chhikara, Navnidhi; Anand, Tanupriya; Sharma, Monika; Singh, Ashish K

    2014-09-01

    Study was conducted to optimize pearl millet grits size for the preparation of acceptable porridge with skimmed milk powder (SMP). Pearl millet porridge was prepared with different grits size (1.410, 0.841, 0.595, and 0.420 mm). A positive (r?=?0.904) correlation was observed between water absorption index and grits size. Porridge showed shear thinning behavior as, initially shear stress increased with increase in shear rate and later on decreased. Porridge prepared with larger grits (1.410 mm) exhibited higher firmness (38.4?±?1.27 N) and viscosity (446?±?3.9 cP), whereas smaller grits (0.420 mm) resulted in less viscous (118.8?±?1.74 cP) and firm (20.4?±?1.85 N) porridge. The medium grits (0.841 mm) produced porridge with acceptable firmness (30.7?±?1.56 N) and viscosity (298.1?±?8.81 cP) with moderate (6.0?±?0.10) acceptability. To improve sensory quality of porridge (grits size 0.841 mm); skimmed milk powder at different levels (0, 5, 10 and 15 %) was added and its effect on various quality parameters was studied. SMP addition significantly (P???0.05) modified the gelatinization and gelling behavior of grits and decreased (P???0.05) all the pasting characteristics except pasting temperature, which increased from 77.1?±?1.85 to 85.9?±?3.46 °C. The peak (499?±?6.6 cP) and final viscosity (450?±?11.9 cP) of porridge (0.841 mm) prepared with 15 % SMP are quite similar. Hence, it maintains viscosity on cooling, similar to maximum viscosity attained during cooking. Keeping in view the rheological, firmness and sensory quality, 0.841 mm grits of pearl millet with 15 % SMP was found optimum for preparation of acceptable porridge. PMID:25190879

  15. The Mars Pathfinder Wheel Abrasion Experiment

    Microsoft Academic Search

    Dale C. Ferguson; David M. Wilt; Aloysius F. Hepp; Joseph C. Kolecki; Mark W. Siebert; Phillip P. Jenkins; David A. Scheiman; Navid S. Fatemi; Richard W. Hoffman

    2001-01-01

    On board the Mars Pathfinder spacecraft, launched in December of 1996, was a small roving vehicle named Sojourner. On Sojourner was an experiment to determine the abrasive characteristics of the Martian surface, called the Wheel Abrasion Experiment (WAE). The experiment worked as follows: one of the wheels of the rover had a strip of black anodized aluminum bonded to the

  16. Wear of elastomeric seals in abrasive slurries

    Microsoft Academic Search

    Hugo M. Ayala; Douglas P. Hart; Oscar C. Yeh; Mary C. Boyce

    1998-01-01

    Seals are a critical aspect of machinery that operates in the presence of abrasive slurries. Seals act to maintain machine lubrication and prevent abrasives from affecting critical components. Over time, however, the slurry will wear the seal and lead to a loss of lubrication and eventual machine failure. It is therefore important to investigate the seal wear process in aims

  17. Cold Spraying Activation Using an Abrasive Admixture

    NASA Astrophysics Data System (ADS)

    Klinkov, S. V.; Kosarev, V. F.

    2012-09-01

    In the present study, on the basis of a two-probability model we theoretically analyze the influence of surface erosion and activation due to abrasive particles impacting on the substrate (coating) surface on the total deposition efficiency of a sprayed mixture of abrasive and metal particles. Relations for the total deposition efficiency derived with regard to the activation effect due to abrasive particles were obtained. In the experiments, the deposition efficiency was measured as a function of the abrasive (SiC) concentration in the initial mixture with copper powder, the size of the abrasive particles, and the working-gas (air) stagnation temperature. Modeling data are compared to the present and previously published experimental data, and a good agreement between the data is shown.

  18. Blast injury.

    PubMed

    de Candole, C A

    1967-01-28

    The shock wave generated by an explosion ("blast wave") may cause injury in any or all of the following: (1) direct impact on the tissues of variations in environmental pressure; (2) flying glass and other debris set in motion by it; (3) propulsion of the body. Injuries in the first category affect gas-containing organs (ears, lungs and intestines), and acute death is attributed to air forced into the coronary vessels via damaged pulmonary alveoli. It is estimated that overpressure sufficient to cause lung injury may occur up to five miles from a 20-megaton nuclear explosion. The greatest single hazard from blast is, however, flying glass, and serious wounding from this cause is possible up to 12 miles from an explosion of this magnitude. PMID:6015742

  19. A semi-fixed abrasive machining technique

    NASA Astrophysics Data System (ADS)

    Yuan, Julong; Wang, Zhiwei; Hong, Tao; Deng, Qianfa; Wen, Donghui; Lv, Binghai

    2009-05-01

    This paper proposes the technique of semi-fixed abrasive machining to reduce or eliminate the surface defects caused by large abrasive grains and improve the efficiency of ultra-precision processing. The method of semi-fixed abrasive machining is described, and a semi-fixed abrasive plate (SFAP) is manufactured. Under the condition of adding or not adding large grains, experiments of semi-fixed and loose abrasive machining for a workpiece of damage-free single crystal silicon are carried out. The surface roughness and SEM micrograph of the workpieces demonstrate that semi-fixed abrasive machining leads to less surface defects, and the existence of large grains has a slight effect on the surface roughness of the workpiece. Single crystal silicon workpieces with a roughness (Ra) of about 0.2 µm are semi-fixed abrasive processed, in order to investigate the influence of load and rotating speed of the SFAP on the surface roughness and material removal rate. No significant variation of the surface roughness is observed when the value of the load or SFAP rotating speed changes, and the material removal rate increases with the increase of the load or SFAP rotating speed, i.e. the machining efficiency can be improved by increasing the load or SFAP rotating speed while the surface quality of the workpiece does not decrease.

  20. Impact-abrasion and abrasion of WC-Co: wear mechanisms in severe environments

    SciTech Connect

    Hawk, Jeffrey A.; Wilson, Rick D.; Osara, K. (Outokumpu Research Oy)

    2003-10-01

    Hard and super-hard materials have very good abrasive wear resistance. However, in many severe wear environments that make use of these materials, impact is a significant component of that environment. Consequently, the behavior of many of these hard materials in impact-wear conditions need to be understood with respect to the mechanisms of material removal such small scale fracture and subsequent crack growth in the carbide. This study details the behavior of several ?hard? materials in abrasion and impact-abrasion focusing on the mechanisms of material removal due to impact and abrasion.

  1. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Tools and Related Equipment § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and...

  2. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Tools and Related Equipment § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and...

  3. Effects of scratching directions on AFM-based abrasive abrasion process

    Microsoft Academic Search

    Y. D. Yan; T. Sun; Y. C. Liang; S. Dong

    2009-01-01

    AFM-based single abrasive abrasion process is widely employed in the surface micro\\/nanomachining for fabrication of structures at the nanometer scale. The wear depth and roughness are significantly important in the application of these structures. To study effects of scratching directions on the wear depth and roughness within the wear mark, single groove scratching test and wear test on the surface

  4. The New BLAST Results Page

    E-print Network

    Levin, Judith G.

    The New BLAST® Results Page Enhanced graphical presentation and added functionality http://blast.ncbi.nlm.nih.gov, 2013 Contact: blast-help@ncbi.nlm.nih.gov Scope NCBI has introduced an enhanced report for search BLAST result page Access to NCBI BLAST web services through its homepage (blast.ncbi.nlm.nih.gov

  5. Influence of granite-grit on nutrient digestibility and haematological parameters of broiler chickens fed rice offal based diets.

    PubMed

    Idachaba, C U; Abeke, F O; Olugbemi, T S; Ademu, L A

    2013-10-01

    A total of 270 broiler chickens were used for the study. The birds were fed common diet containing 23% Crude protein and 2864 kcal kg(-1) Metabolizable energy at the starter phase while 20% Crude protein and 2923 kcal kg(-1) Metabolizable energy was fed at the finisher phase. Starter and finisher diets contained 10 and 15% inclusion levels of rice offal respectively. Granite grit was added to the basal diet at 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0 g per bird per month thus making a total of six treatments. Each treatment was replicated three times with 15 birds per replicate in a completely randomized design. Packed cell volume and haemoglobin level were not significantly (p>0.05) affected by dietary grit levels while total protein increased across the graded levels of granite grit. Crude protein, crude fibre and nitrogen free extract significantly (p<0.05) improved with increasing grit levels. These parameters improved up to the highest level of grit addition (10.0 g) granite-grit. It was concluded that 10.0 g granite grit per bird per month is beneficial to broiler chickens as it allows for efficient nutrient utilization. Further study to determine the optimum level of granite grit in broiler diet is encouraged since result obtained showed the optimum level was not attained. PMID:24502172

  6. Structural blast design

    E-print Network

    Kieval, Tamar S. (Tamar Shoshana), 1980-

    2004-01-01

    Blast design is a necessary part of design for more buildings in the United States. Blast design is no longer limited to underground shelters and sensitive military sites, buildings used by the general public daily must ...

  7. Facile fabrication of superhydrophobic surface with excellent mechanical abrasion and corrosion resistance on copper substrate by a novel method.

    PubMed

    Su, Fenghua; Yao, Kai

    2014-06-11

    A novel method for controllable fabrication of a superhydrophobic surface with a water contact angle of 162 ± 1° and a sliding angle of 3 ± 0.5° on copper substrate is reported in this Research Article. The facile and low-cost fabrication process is composed from the electrodeposition in traditional Watts bath and the heat-treatment in the presence of (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane (AC-FAS). The superhydrophobicity of the fabricated surface results from its pine-cone-like hierarchical micro-nanostructure and the assembly of low-surface-energy fluorinated components on it. The superhydrophobic surface exhibits high microhardness and excellent mechanical abrasion resistance because it maintains superhydrophobicity after mechanical abrasion against 800 grit SiC sandpaper for 1.0 m at the applied pressure of 4.80 kPa. Moreover, the superhydrophobic surface has good chemical stability in both acidic and alkaline environments. The potentiodynamic polarization and electrochemical impedance spectroscopy test shows that the as-prepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Cu substrate. In addition, the as-prepared superhydrophobic surface has self-cleaning ability. It is believed that the facile and low-cost method offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials. PMID:24796223

  8. Universal scaling relations for pebble abrasion

    NASA Astrophysics Data System (ADS)

    Litwin, K. L.; Jerolmack, D. J.

    2012-12-01

    The process of abrasion of gravel in bed load transport results from particle-to-particle collisions, where the energy involved is sufficient to cause chipping and spallation but not fragmentation of parent grains. The removed rock material is not infinitesimal; daughter products as large as coarse sand can be produced. Although previous work has shown that lithology, grain shape, and energy of collision are contributing factors that control abrasion rates of river-bed material, little is known regarding the relationship between these factors and diminution rates. Here we explicitly isolate and investigate how these three factors influence rates of abrasion and the size distribution of daughter products, with laboratory experiments. The apparatus is a double pendulum (Newton's cradle) that produces well-controlled binary collisions. A high-speed camera precisely measures collision energy, while mass of parent rocks. and the size and shape distributions of daughter products, are measured periodically. We examined abrasion of initially square-cut 'rocks' as they underwent successive collisions in the binary collision apparatus. We have examined mass loss rate for varied lithologies, and observe a similar power-law relationship between impact energy and mass abraded. When normalized by sensible material properties, mass loss curves for all materials collapse onto a single curve, suggesting that the underlying mechanics of abrasion for different materials are the same. The relationship does not display the linear trend expected from pure energetics, and we suggest that this is a shape effect as protruding - and hence easily eroded - corners are worn away. Analysis of daughter-product particle size distributions for different lithology fragments - including natural rocks and also bricks - show the same functional form. Surprisingly, it is the power-law relation expected for brittle materials undergoing fragmentation. This suggests that brittle fracture theory also describes the abrasion of river sediments, albeit over a limited length scale that may be associated with skin depth over which collision energy is attenuated. If these results are general, they may be used to search for the signature of abrasion in size distributions of sand and silt particles in natural streams. The apparent universality of both mass loss curves and particle size distributions is in need of theoretical investigation to better understand the underlying mechanics. However, the results are already proving useful for interpreting the role of in-stream abrasion in downstream fining and the production of sand in field studies.

  9. ABRASIVE-BASED NANO-FINISHING TECHNIQUES: AN OVERVIEW

    Microsoft Academic Search

    V. K. Jain

    2008-01-01

    The surface finishing techniques can be divided into two categories: traditional and advanced. To overcome some of the problems of traditional finishing techniques, hybridized processes have been evolved by the researchers. Some of the advanced finishing processes that have been reviewed are abrasive flow machining (AFM), magnetorheological finishing (MRF), magnetorheological abrasive flow finishing (MRAFF), magnetic abrasive finishing (MAF), chemo mechanical

  10. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...An oral cavity abrasive polishing agent is a device in paste or powder form that contains an abrasive material, such as silica pumice, intended to remove debris from the teeth. The abrasive polish is applied to the teeth by a handpiece attachment...

  11. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...An oral cavity abrasive polishing agent is a device in paste or powder form that contains an abrasive material, such as silica pumice, intended to remove debris from the teeth. The abrasive polish is applied to the teeth by a handpiece attachment...

  12. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...An oral cavity abrasive polishing agent is a device in paste or powder form that contains an abrasive material, such as silica pumice, intended to remove debris from the teeth. The abrasive polish is applied to the teeth by a handpiece attachment...

  13. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...An oral cavity abrasive polishing agent is a device in paste or powder form that contains an abrasive material, such as silica pumice, intended to remove debris from the teeth. The abrasive polish is applied to the teeth by a handpiece attachment...

  14. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...An oral cavity abrasive polishing agent is a device in paste or powder form that contains an abrasive material, such as silica pumice, intended to remove debris from the teeth. The abrasive polish is applied to the teeth by a handpiece attachment...

  15. Dust transport and abrasion assessment within simulated standing vegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues are useful in protecting the top soil from depletion and abrasion due to wind erosion. A wind tunnel study was done to measure sand transport and abrasion energies within the simulated artificial standing vegetation. Wind profiles, relative abrasion energies and rates of sand dischar...

  16. Abrasion Technology for Electric Submergible Pumps

    Microsoft Academic Search

    D. G. King; F. T. Traylor; R. E. Stewart

    1983-01-01

    This study describes the results of a 5-yr investigation of sand abrasion phenomena in conventional electric submersible pumps. The investigation includes a review of the available literature on 2 body and 3 body wear processes in the presence of corrosive fluids, and the development of laboratory test methods from which baseline wear rates for conventional pumps can be established. These

  17. Technological Advances in Fine Abrasive Processes

    Microsoft Academic Search

    R. Komanduri; D. A. Lucca; Y. Tani

    1997-01-01

    Fine abrasives, be they loose or fixed, are invariably used in the production of components of the highest quality in terms of form and finish accuracy, and surface integrity. While optical, mechanical, and electronic applications of advanced ceramics, glasses, and semiconductors may require high form and finish accuracies (e.g., roughnesses in the angstrom range), the depth and nature of the

  18. Policy-Based Cognitive Radios David Wilkins, Grit Denker, Mark-Oliver Stehr,

    E-print Network

    Policy-Based Cognitive Radios David Wilkins, Grit Denker, Mark-Oliver Stehr, Daniel Elenius, Rukman, and show how this reasoner can be used with various cognitive radios (in this case, an XG radio-defined cognitive radio. Such cog- nitive radios must be able to sense their environment, must be aware of their own

  19. Effect of extrusion cooking, with and without added glucose, on fumonisin B1 in corn grits.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking reduces fumonisin concentrations in corn but how it affects fumonisin toxicity is not well characterized. A batch of corn grits (SG) was spiked with fumonisin B1 (FB1) and two batches (FG1 & FG2) were contaminated with FB1 by fermentation. Respective FB1 concentrations of SG, FG1...

  20. Abrasive wear behaviour of electrodeposited nanocrystalline materials

    NASA Astrophysics Data System (ADS)

    Jeong, Daehyun

    The effect of grain size refinement on the abrasive wear behaviour of nanocrystalline Ni, Ni-P and Co electrodeposits and the critical materials properties that influence the abrasive wear resistance were studied using the Taber wear test. As the grain size of Ni decreased from 90 mum to 13 nm, the dominant abrasive wear mode changed from ploughing to cutting and the Taber wear resistance was considerably improved by the increases in hardness and surface elastic properties. The abrasive wear behaviour of Ni with various grain sizes can be described using the attack angle model, which takes into consideration the randomly dispersed Al2O3 abrasive particles in the Taber wheel with various sizes, shapes and orientations. Depending on the phosphorus content, the nickel-phosphorus (Ni-P) alloys containing up to 6 wt.% P had nanocrystalline or mixed nanocrystalline-amorphous structures and both regular and inverse Hall-Petch behaviour were observed as a result of the microstructural changes with increasing P content/decreasing grain size. The wear resistance, like hardness, followed the Hall-Petch type behaviour, demonstrating that the smallest grain size does not necessarily provide the best wear resistance. For all Ni-P alloys, the wear resistance was improved by heat treatment due to Ni3P precipitates and, for materials with high P content, nanocrystallization of the amorphous phase. For heat-treated Ni-P alloys, however, the highest hardness did not give the best wear resistance. Despite the grain size reduction of Co from 10 mum to 17 nm, there was no significant change in the wear resistance due to the unusually high degree of plastic deformation of the nanocrystalline material. In addition to hardness and surface elastic properties which are usually considered important material properties that control the abrasive wear resistance, Taber wear ductility was introduced as a new material intrinsic property which can be applied to explain abrasive wear resistance for cases when the former two parameters are poor indicators such as for heat-treated Ni-P with high P content and nanocrystalline Co. The results of this study have shown that both nanocrystalline Ni and Ni-P coatings could be of significant technological importance in the area of wear resistant coatings.

  1. Surface modification of titanium using steel slag ball and shot blasting treatment for biomedical implant applications

    NASA Astrophysics Data System (ADS)

    Arifvianto, Budi; Suyitno; Mahardika, Muslim

    2013-08-01

    Surface modification is often performed using grit or shot blasting treatment for improving the performances of biomedical implants. The effects of blasting treatments using steel slag balls and spherical shots on the surface and subsurface of titanium were studied in this paper. The treatments were conducted for 60-300 s using 2-5 mm steel slag balls and 3.18 mm spherical shots. The surface morphology, roughness, and elemental composition of titanium specimens were examined prior to and after the treatments. Irregular and rough titanium surfaces were formed after the treatment with the steel slag balls instead of the spherical shots. The former treatment also introduced some bioactive elements on the titanium surface, but the latter one yielded a harder surface layer. In conclusion, both steel slag ball and shot blasting treatment have their own specialization in modifying the surface of metallic biomaterials. Steel slag ball blasting is potential for improving the osseointegration quality of implants; but the shot blasting is more appropriate for improving the mechanical properties of temporary and load bearing implants, such as osteosynthesis plates.

  2. Blast furnace stove control

    SciTech Connect

    Muske, K.R. [Villanova Univ., PA (United States). Dept. of Chemical Engineering; Hansen, G.A.; Howse, J.W.; Cagliostro, D.J. [Los Alamos National Lab., NM (United States); Chaubal, P.C. [Inland Steel Industries Inc., East Chicago, IN (United States). Research Labs.

    1998-12-31

    This paper outlines the process model and model-based control techniques implemented on the hot blast stoves for the No. 7 Blast Furnace at the Inland Steel facility in East Chicago, Indiana. A detailed heat transfer model of the stoves is developed. It is then used as part of a predictive control scheme to determine the minimum amount of fuel necessary to achieve the blast air requirements. The controller also considers maximum and minimum temperature constraints within the stove.

  3. The abrasive wear of single and multiphase materials

    SciTech Connect

    McGee, A.C.

    1990-01-01

    Experimental two-body abrasion test equipment was developed to study the effects of temperature and liquid environments on abrasion. The effect of various liquids was determined for AISI 1018 Steel and 1100 Al. The effect of temperature on abrasion was determined for 1100 Al and Cu. An explanation based on adiabatic shear observed in metal cutting is proposed. The size effect, a marked decrease in the abrasion rate observed for abrasive particles less than approximately 100 {mu}m, is investigated for Al and Cu. The effect of temperature and various liquids was also determined. The rule of mixtures for abrasive wear was theoretically and experimentally investigated for Graphite/Epoxy (Gr/Ep) continuous-fiber composite, two chopped-fiber composites, Al, Si, Al-Si alloys, and directionally solidified white cast iron. The size effect was observed for Gr/Ep. The effect of sample orientation on the abrasion rate of Gr/Ep was investigated and an explanation proposed. The Al, Si, Al-Si exhibited a change of relative abrasion resistance with abrasive particle size which was a different type of size effect than that previously discussed. The abrasion rate of the other multiphase materials was determined and their surfaces were investigated by scanning electron microscopy.

  4. Controlled Toothbrush Abrasion of Softened Human Enamel

    Microsoft Academic Search

    J. Voronets; T. Jaeggi; W. Buergin; A. Lussi

    2008-01-01

    The aim of this in vitro study was to compare toothbrush abrasion of softened enamel after brushing with two (soft and hard) toothbrushes. One hundred and fifty-six human enamel specimens were indented with a Knoop diamond. Salivary pellicle was formed in vitro over a period of 3 h. Erosive lesions were produced by means of 1% citric acid. A force-measuring

  5. Circular Signs of the Rock Abrasion Tool

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image was taken by Mars Exploration Rover Opportunity's front hazard-avoidance camera, providing a circular sign of the success of the rover's first grinding of a rock. The round, shallow hole seen in this image is on a rock dubbed 'McKittrick,' located in the 'El Capitan' area of the larger outcrop near Opportunity's landing site.

    Opportunity used its rock abrasion tool to grind off a patch of rock 45.5 millimeters (1.8 inches) in diameter during the 30th martian day, or sol, of its mission (Feb. 23, 2004). The grinding exposed fresh rock for close inspection by the rover's microscopic imager and two spectrometers located on its robotic arm. The Honeybee Robotics team, which designed and operates the rock abrasion tool, determined the depth of the cut at 'McKittrick' to be 4.4 millimeters (0.17 inches) deep.

    On sol 34 (Feb. 27, 2004), the rover is scheduled to grind into its second target on the 'El Capitan' area, a rock dubbed 'Guadalupe' in the upper middle part of this image. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

  6. Predicting abrasive wear with coupled Lagrangian methods

    NASA Astrophysics Data System (ADS)

    Beck, Florian; Eberhard, Peter

    2015-05-01

    In this paper, a mesh-less approach for the simulation of a fluid with particle loading and the prediction of abrasive wear is presented. We are using the smoothed particle hydrodynamics (SPH) method for modeling the fluid and the discrete element method (DEM) for the solid particles, which represent the loading of the fluid. These Lagrangian methods are used to describe heavily sloshing fluids with their free surfaces as well as the interface between the fluid and the solid particles accurately. A Reynolds-averaged Navier-Stokes equations model is applied for handling turbulences. We are predicting abrasive wear on the boundary geometry with two different wear models taking cutting and deformation mechanisms into account. The boundary geometry is discretized with special DEM particles. In doing so, it is possible to use the same particle type for both the calculation of the boundary conditions for the SPH method as well as the DEM and for predicting the abrasive wear. After a brief introduction to the SPH method and the DEM, the handling of the boundary and the coupling of the fluid and the solid particles are discussed. Then, the applied wear models are presented and the simulation scenarios are described. The first numerical experiment is the simulation of a fluid with loading which is sloshing inside a tank. The second numerical experiment is the simulation of the impact of a free jet with loading to a simplified pelton bucket. We are especially investigating the wear patterns inside the tank and the bucket.

  7. Geothermal Energy Market Study on the Atlantic Coastal Plain. GRITS (Version 9): Model Description and User's Guide

    SciTech Connect

    Kroll, Peter; Kane, Sally Minch [eds.

    1982-04-01

    The Geothermal Resource Interactive Temporal Simulation (GRITS) model calculates the cost and revenue streams for the lifetime of a project that utilizes low to moderate temperature geothermal resources. With these estimates, the net present value of the project is determined. The GRITS model allows preliminary economic evaluations of direct-use applications of geothermal energy under a wide range of resource, demand, and financial conditions, some of which change over the lifetime of the project.

  8. Performance of the light trigger system in the liquid xenon ?-ray imaging telescope LXeGRIT

    Microsoft Academic Search

    Uwe Oberlack; Elena Aprile; Alessandro Curioni; Karl-Ludwig Giboni

    2001-01-01

    LXeGRIT is a balloon-borne Compton telescope for MeV ?-ray astrophysics, based on a liquid xenon time projection chamber with charge and light readout. The energy and direction of an incident ?-ray are reconstructed from the three-dimensional locations and energy deposits of individual interactions taking place in the homogeneous detector volume. While the charge signals provide energy information and X-Y-positions, the

  9. Sycamore grit siltstone: informal member of Upper Devonian in north-central West Virginia

    Microsoft Academic Search

    Larry J. Cavallo

    1988-01-01

    The Upper Devonian Sycamore grit siltstone (an informal member of the Brallier Formation) was studied both in outcrop and subsurface. Outcrops consist of approximately 80 ft of thin to medium-bedded, brownish-gray, argillaceous siltstones and olive-gray shales. The Sycamore was presumably deposited by or associated with turbidity currents, because sedimentary structures include incomplete Bouma sequences and flute casts. Petrographic studies from

  10. Computer cast blast modelling

    Microsoft Academic Search

    S. Chung; M. McGill; D. S. Preece

    1994-01-01

    Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than

  11. Lightweight blast shield

    DOEpatents

    Mixon, Larry C. (Madison, AL); Snyder, George W. (Huntsville, AL); Hill, Scott D. (Toney, AL); Johnson, Gregory L. (Decatur, AL); Wlodarski, J. Frank (Huntsville, AL); von Spakovsky, Alexis P. (Huntsville, AL); Emerson, John D. (Arab, AL); Cole, James M. (Huntsville, AL); Tipton, John P. (Huntsville, AL)

    1991-01-01

    A tandem warhead missile arrangement that has a composite material housing structure with a first warhead mounted at one end and a second warhead mounted near another end of the composite structure with a dome shaped composite material blast shield mounted between the warheads to protect the second warhead from the blast of the first warhead.

  12. The grit effect: predicting retention in the military, the workplace, school and marriage.

    PubMed

    Eskreis-Winkler, Lauren; Shulman, Elizabeth P; Beal, Scott A; Duckworth, Angela L

    2014-01-01

    Remaining committed to goals is necessary (albeit not sufficient) to attaining them, but very little is known about domain-general individual differences that contribute to sustained goal commitment. The current investigation examines the association between grit, defined as passion and perseverance for long-term goals, other individual difference variables, and retention in four different contexts: the military, workplace sales, high school, and marriage. Grit predicted retention over and beyond established context-specific predictors of retention (e.g., intelligence, physical aptitude, Big Five personality traits, job tenure) and demographic variables in each setting. Grittier soldiers were more likely to complete an Army Special Operations Forces (ARSOF) selection course, grittier sales employees were more likely to keep their jobs, grittier students were more likely to graduate from high school, and grittier men were more likely to stay married. The relative predictive validity of grit compared to other traditional predictors of retention is examined in each of the four studies. These findings suggest that in addition to domain-specific influences, there may be domain-general individual differences which influence commitment to diverse life goals over time. PMID:24550863

  13. The grit effect: predicting retention in the military, the workplace, school and marriage

    PubMed Central

    Eskreis-Winkler, Lauren; Shulman, Elizabeth P.; Beal, Scott A.; Duckworth, Angela L.

    2013-01-01

    Remaining committed to goals is necessary (albeit not sufficient) to attaining them, but very little is known about domain-general individual differences that contribute to sustained goal commitment. The current investigation examines the association between grit, defined as passion and perseverance for long-term goals, other individual difference variables, and retention in four different contexts: the military, workplace sales, high school, and marriage. Grit predicted retention over and beyond established context-specific predictors of retention (e.g., intelligence, physical aptitude, Big Five personality traits, job tenure) and demographic variables in each setting. Grittier soldiers were more likely to complete an Army Special Operations Forces (ARSOF) selection course, grittier sales employees were more likely to keep their jobs, grittier students were more likely to graduate from high school, and grittier men were more likely to stay married. The relative predictive validity of grit compared to other traditional predictors of retention is examined in each of the four studies. These findings suggest that in addition to domain-specific influences, there may be domain-general individual differences which influence commitment to diverse life goals over time. PMID:24550863

  14. Controlled toothbrush abrasion of softened human enamel.

    PubMed

    Voronets, J; Jaeggi, T; Buergin, W; Lussi, A

    2008-01-01

    The aim of this in vitro study was to compare toothbrush abrasion of softened enamel after brushing with two (soft and hard) toothbrushes. One hundred and fifty-six human enamel specimens were indented with a Knoop diamond. Salivary pellicle was formed in vitro over a period of 3 h. Erosive lesions were produced by means of 1% citric acid. A force-measuring device allowed a controlled toothbrushing force of 1.5 N. The specimens were brushed either in toothpaste slurry or with toothpaste in artificial saliva for 15 s. Enamel loss was calculated from the change in indentation depth of the same indent before and after abrasion. Mean surface losses (95% CI) were recorded in ten treatment groups: (1) soft toothbrush only [28 (17-39) nm]; (2) hard toothbrush only [25 (16-34) nm]; (3) soft toothbrush in Sensodyne MultiCare slurry [46 (27-65) nm]; (4) hard toothbrush in Sensodyne MultiCare slurry [45 (24-66) nm]; (5) soft toothbrush in Colgate sensation white slurry [71 (55-87) nm]; (6) hard toothbrush in Colgate sensation white slurry [85 (60-110) nm]; (7) soft toothbrush with Sensodyne MultiCare [48 (39-57) nm]; (8) hard toothbrush with Sensodyne MultiCare [40 (29-51) nm]; (9) soft toothbrush with Colgate sensation white [51 (37-65) nm]; (10) hard toothbrush with Colgate sensation white [52 (36-68) nm]. Neither soft nor hard toothbrushes produced significantly different toothbrush abrasion of softened human enamel in this model (p > 0.05). PMID:18663297

  15. Mars Pathfinder Wheel Abrasion Experiment Ground Test

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Siebert, Mark W.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

  16. Abrasion-Resistant Coating for Flexible Insulation

    NASA Technical Reports Server (NTRS)

    Mui, D.; Headding, R. E.

    1986-01-01

    Ceramic coating increases durability and heat resistance of flexible high-temperature insulation. Coating compatible with quartz-fabric insulation allowing it to remain flexible during and after repeated exposures to temperatures of 1,800 degree F (982 degree C). Prevents fabric from becoming brittle while increasing resistance to aerodynamic abrasion and loading. Coating consists of penetrating precoat and topcoat. Major ingredients high-purity colloidal silica binder and ground silica filler, which ensure stability and compatibility with fabric at high temperatures. Both precoat and topcoat cured at room temperature.

  17. New blast weapons.

    PubMed

    Dearden, P

    2001-02-01

    Over the last decade a large number of weapon systems have appeared that use blast as their primary damage mechanism. This is a notable trend; until recently very few warheads relied on blast as their primary output. Most warheads in service use explosives to drive metal such as fragments and shaped charge jets to engage targets. New technologies are now being integrated into warheads that claim to have enhanced blast performance. Blast weapons could have been designed to fill a gap in capability; they are generally used for the attack of 'soft' targets including personnel, both in the open and within protective structures. With the increased number and range of these weapons, it is likely that UK forces will have to face them in future conflicts. This paper briefly describes fuel-air explosive blast weapons and reviews a range of enhanced blast weapons that have been developed recently. The paper concludes with a brief discussion on the reasons why enhanced blast technologies may be proliferating and how this could affect the Defence Medical Services. PMID:11307681

  18. Hydroxyapatite and fluorapatite coatings on dental screws: effects of blast coating process and biological response.

    PubMed

    Dunne, Conor F; Twomey, Barry; Kelly, Ciara; Simpson, Jeremy C; Stanton, Kenneth T

    2015-01-01

    This paper describes the deposition of hydroxyapatite (HA) and fluorapatite (FA) onto titanium dental screws using a novel ambient temperature coating technique named CoBlast. The process utilises a coating medium and a blast medium sprayed simultaneously at the substrate surface. The blast medium was a sintered apatite (sHA) and two particles sizes (<106 and <180 µm) were used to assess their influence on the coating process. The influence of the coating process on the coating composition, coating adhesion, screw morphology and screw microstructure was examined. XRD analysis revealed the coating crystallinity was the same as the original HA and FA feedstock powders. Examining the screw's morphology, the threads of the CoBlasted screws exhibited rounding compared to the unmodified screw. This is due to the abrasive nature of the CoBlast process. The degree of rounding was more significant for the screws blasted with the 180 µm sHA than the 106 µm sHA. The blast media particle size significantly influences the surface roughness of both the substrate and coating and the microstructure of the substrate. The screws did not exhibit any loss of coating after insertion into a model bone material, indicating that the coating was strongly adhered to the substrate. There was no statistically significant difference in cell attachment and cell morphology on the unmodified substrates compared to the coated substrates. In conclusion, the CoBlast process can be used to deposit HA and FA onto complex geometries such as dental screws. The choice of blast medium particle size influences the screws morphology. The coating process does not negatively impact on the cell attachment and morphology in vitro. PMID:25578701

  19. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting...

  20. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three ...

  1. Sand abrasion injury and biomass partitiioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three ...

  2. Abrasion of 6 dentifrices measured by vertical scanning interference microscopy

    PubMed Central

    PASCARETTI-GRIZON, Florence; MABILLEAU, Guillaume; CHAPPARD, Daniel

    2013-01-01

    Objectives The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). Material and Methods Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscopy and microanalysis characterized the shape and nature of the particles. Standardized and polished blocks of poly(methylmethacrylate) were brushed with a commercial electric toothbrush with the dentifrices. VSI quantified the mean roughness (Ra) and illustrated in 3D the abraded areas. Results Toothpastes induced a limited abrasion. Toothpowders induced a significantly higher roughness linked to the size of the abrasive particles. One powder (Gencix® produced a high abrasion when used with a standard testing weight. However, the powder is based on pumice particles covered by a plant homogenate that readily dissolves in water. When used in the same volume, or after dispersion in water, Ra was markedly reduced. Conclusion Light and electron microscopy characterize the abrasive particles and VSI is a new tool allowing the analysis of large surface of abraded materials. PMID:24212995

  3. Cotton seedling abrasion and recovery from wind blown sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of crops are exposed to wind blown sand abrasion each year and in many instances the damage is thought to be severe enough to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton (Gossypium hirsutum L.) seedlings...

  4. Dry and wet abrasive resistance of Inconel 600 and stellite

    Microsoft Academic Search

    M. Vite; M. Castillo; L. H. Hernández; G. Villa; I. H. Cruz; D. Stéphane

    2005-01-01

    This paper is a comparative study of the influence of different parameters in abrasive wear in dry and wet conditions of Inconel 600 and stellite. The parameters considered are chemical composition and microstructure characteristics. These alloys are deposited by the shield metal arc welding (SMAW) process, on ASTM A-36 steel. The abrasion tests were carried out using a dry sand\\/rubber

  5. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of acres of crops are exposed to wind blown sand abrasion injury each year and in many instances the damage is thought to be sufficiently severe to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton seedlings. Seedlings of ...

  6. Recycling of spent abrasive media in nonstructural concrete

    Microsoft Academic Search

    Matthew T. Webster; Raymond C. Loehr

    1996-01-01

    Spent abrasive media from bridge repainting operations contain metals which may result in the media being classified as hazardous under the Environmental Protection Agency (EPA) Toxicity Characteristic (TC) criteria. The management of spent abrasive media by recycling it as a component of nonstructural concrete was investigated. Success was measured with respect to the TC criteria for leaching and a compressive

  7. Evaluation of particles released from single-wall carbon nanotube/polymer composites with or without thermal aging by an accelerated abrasion test.

    PubMed

    Jiang, Lin; Kondo, Akira; Shigeta, Masahiro; Endoh, Shigehisa; Uejima, Mitsugu; Ogura, Isamu; Naito, Makio

    2014-01-01

    To provide data required for assessing the environmental health and safety risks of nanocomposites, abrasion-induced particle release from single-wall carbon nanotube (SWCNT)/polymer composites with or without thermal aging were evaluated by a shot blast system. First, overall composite weight loss (i.e., overall particle release) as a result of shot blasting was measured. Incorporating 5 wt% SWCNTs in polystyrene (PS) matrix was observed to reduce overall particle release by approximately 30% compared with pure PS. Heat treatment of the 5 wt% SWCNT/PS composites at 100°C for 10 days induced very slight change in overall particle release due to shot blasting. However, heat treatment at 350°C for 1 hr greatly deteriorated the abrasion resistance of the composites, enhancing overall particle release. Second, to verify the existence and form of SWCNTs released from the composites, released particles were observed by electron microscopy. Micron-sized particles with protruding SWCNTs and submicron-sized SWCNT clusters were observed in the particles released from the composites. Heat treatment of the composites at 350°C for 1 hr enhanced SWCNT release, which mainly formed clusters or rope-like bundles. PMID:24628695

  8. Evidence for Martian electrostatic charging and abrasive wheel wear from the Wheel Abrasion Experiment on the Pathfinder Sojourner rover

    Microsoft Academic Search

    Dale C. Ferguson; Joseph C. Kolecki; Mark W. Siebert; David M. Wilt; Jacob R. Matijevic

    1999-01-01

    The Wheel Abrasion Experiment (WAE) on the Mars Pathfinder rover was designed to find out how abrasive the Martian dust would be on strips of pure metals attached to one of the wheels. A specially modified wheel, with 15 thin film samples (five each of three different metals), specularly reflected sunlight to a photovoltaic sensor. When the wheel was rotated

  9. Effect of operating parameters on mechanical expression of solvent-soaked soybean-grits.

    PubMed

    Sinha, Lalan Kumar; Haldar, Swarrna; Majumdar, Gautam Chandra

    2015-05-01

    Oil from soybean is obtained mostly by solvent extraction of soybean flakes. Legislation banning the use of hexane as solvent for extracting edible vegetable oil has forced a search for an alternative solvent and for developing a suitable oil recovery process. Expellers are being used for obtaining vegetable oil by mechanical means (expression) from oil seeds having oil content higher than 20 %. It was felt, in view of the stiffness of the soybean matrix, a combination of solvent treatment and expression could be a cheaper alternative; thus an attempt has been made here to develop a two stage process constituting soaking of soybean grits in solvent followed by mechanical compression (hydraulic press) of solvent-soaked grits to recover oil. The present work aimed at studying the effect of various process parameters on oil yield from solvent soaked soybean-grits during soaking as well as pressing stages using the solvents: hexane, ethanol (alternative solvent). The process parameters were identified through holistic approach. The dependant variable was oil recovery (expressed as fraction of initial oil content of soybean) whereas the independent parameters were particle size, solvent-bean mass ratio, soaking time, soaking temperature, applied pressure and pressing time. The effect of each of the above parameters on fractional oil recovery (FOR) was studied. The results of the present study indicate that the above parameters have a significant effect on the fractional oil recovery with particle size, soaking temperature, soaking time and pressing time being the most significant factors. The present study also indicates that ethanol can be used as an alternate solvent to hexane by optimizing the factors as discussed in this paper. PMID:25892794

  10. REMOVAL AND CONTAINMENT OF LEAD-BASED PAINT VIA NEEDLE SCALERS

    EPA Science Inventory

    This report describes a comparative technical and economic evaluation of using a dustless needlegun system versus a conventional abrasive grit blasting system in the removal of lead-based paint from steel structures. he objective of the study was to comparatively analyze the oper...

  11. REMOVAL AND CONTAINMENT OF LEAD-BASED PAINT VIA NEEDLE SCALERS

    EPA Science Inventory

    This report describes a comparative technical and economic evaluation of using a dustless needlegun system versus a conventional abrasive grit blasting system in the removal of lead-based paint from steel structures. The objective of the study was to comparatively analyze the ope...

  12. Laser Surface Preparation and Bonding of Aerospace Structural Composites

    NASA Technical Reports Server (NTRS)

    Belcher, Marcus A.; Wohl, Christopher J.; Connell, John W.

    2009-01-01

    A Nd:YAG laser was used to etch patterns conducive to adhesive bonding onto CFRP surfaces. These were compared to typical pre-bonding surface treatments including grit blasting, manual abrasion, and peel ply. Laser treated composites were then subjected to optical microscopy, contact angle measurements, and post-bonding mechanical testing.

  13. Method for removing surface-damaged layers from nickel alloys

    NASA Technical Reports Server (NTRS)

    Fawley, R. W.

    1968-01-01

    Electrical discharge machining /EDM/ damaged layer can be effectively removed from Rene 41, Inconel 625, Inconel 718, and Monel K-500 by abrasive-grit blasting or electropolishing /at room temperature/ at a current density of 5A/inches squared in a water solution of phosphoric and sulfuric acids.

  14. Mechanics, kinematics and geometry of pebble abrasion from binary collisions

    NASA Astrophysics Data System (ADS)

    Miller, K. L.; Jerolmack, D. J.

    2014-12-01

    As sediment is transported downstream as bedload, it collides with the bed causing sharp edges to chip and wear away, rounding the rock through the process of abrasion. Previous work has linked abrasion to downstream fining and rounding of grains, however, there has been little attempt to understand the underlying kinematics of abrasion. Furthermore, most studies neglect the fine particle produced during the abrasion process, as the initial grain gets smaller and rounder. In this research, we preform well-controlled laboratory experiments to determine the functional dependence between impact energy and mass lost from abrasion. We use a double-pendulum "Newton's Cradle" set-up to examine the abrasion between two grains and with a high-speed camera, we can quantify the impact energies during collision. Results from experiments verify that mass loss is proportional to kinetic energy. We define a material parameter that incorporates material density, Young's modulus, and tensile stress and show that this parameter is directly related to the proportionality between mass loss and energy. We identify an initial region of the mass loss curves in which abrasion is independent of energy and material properties; results suggest this region is determined by shape. We show that grain size distributions of daughter products are universal and independent of material; they follow a Weibull distribution, which is expected distribution from brittle fracture theory. Finally, scanning electron microscope (SEM) images show a thin damage zone near the surface, suggesting that collision energy is attenuated over some small skin depth. Overall, we find that pebble abrasion by collision can be characterized by two universal scaling relations - the mass loss versus energy curves and the size distribution of daughter products. Results will be useful for estimating expected abrasion rates in the field, and additionally demonstrate that low-energy collisions produce large quantities of sand and smaller grains.

  15. Micro Fluidic Channel Machining on Fused Silica Glass Using Powder Blasting

    PubMed Central

    Jang, Ho-Su; Cho, Myeong-Woo; Park, Dong-Sam

    2008-01-01

    In this study, micro fluid channels are machined on fused silica glass via powder blasting, a mechanical etching process, and the machining characteristics of the channels are experimentally evaluated. In the process, material removal is performed by the collision of micro abrasives injected by highly compressed air on to the target surface. This approach can be characterized as an integration of brittle mode machining based on micro crack propagation. Fused silica glass, a high purity synthetic amorphous silicon dioxide, is selected as a workpiece material. It has a very low thermal expansion coefficient and excellent optical qualities and exceptional transmittance over a wide spectral range, especially in the ultraviolet range. The powder blasting process parameters affecting the machined results are injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns. In this study, the influence of the number of nozzle scanning, abrasive particle size, and pattern size on the formation of micro channels is investigated. Machined shapes and surface roughness are measured using a 3-dimensional vision profiler and the results are discussed.

  16. Method for forming an abrasive surface on a tool

    DOEpatents

    Seals, Roland D. (Oak Ridge, TN); White, Rickey L. (Harriman, TN); Swindeman, Catherine J. (Knoxville, TN); Kahl, W. Keith (Knoxville, TN)

    1999-01-01

    A method for fabricating a tool used in cutting, grinding and machining operations, is provided. The method is used to deposit a mixture comprising an abrasive material and a bonding material on a tool surface. The materials are propelled toward the receiving surface of the tool substrate using a thermal spray process. The thermal spray process melts the bonding material portion of the mixture, but not the abrasive material. Upon impacting the tool surface, the mixture or composition solidifies to form a hard abrasive tool coating.

  17. Friction and vibration of automotive brake pads containing different abrasive particles

    Microsoft Academic Search

    Sung Soo Kim; Hee Jung Hwang; Min Wook Shin; Ho Jang

    2011-01-01

    Automotive brake friction materials with four different abrasive particles were investigated. The abrasives used in this study were commercial grade silicon carbide, zircon, quartz and magnesia. For microscopic understanding of friction and wear by abrasive particles in the brake friction material, single-particle scratch tests followed by scratch tests with multiple particles were performed first to understand the behavior of abrasive

  18. The meaning of high stress abrasion and its application in white cast irons

    Microsoft Academic Search

    J. D. Gates; G. J. Gore; M. J. P. Hermand; M. J. P. Guerineau; P. B. Martin; J. Saad

    2007-01-01

    White cast irons perform much less favourably in industrial service environments such as ball mills than would be predicted by standard laboratory abrasion tests. Pin abrasive tests are widely thought to simulate high stress abrasion, but in reality they grossly over-estimate service lives of white iron mill liners compared to pearlitic steel liners. The ‘impact-abrasion’ hypothesis has suggested that the

  19. Experimental Study of Grit Particle Enhancement in Non-Shock Ignition

    NASA Astrophysics Data System (ADS)

    Browning, Richard V.; Peterson, Paul D.; Roemer, Edward L.; Oldenborg, Michael R.; Thompson, Darla G.; Deluca, Racci

    2006-07-01

    The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper, we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested with three conditions: (1) smooth steel anvils, (2) standard flint sandpaper, and (3) shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories.

  20. Experimental Study of Grit Particle Enhancement in Non-Shock Ignition of PBX 9501

    NASA Astrophysics Data System (ADS)

    Peterson, Paul

    2005-07-01

    The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested in three conditions, (1) with smooth steel anvils, (2) with standard flint sandpaper, and (3) with shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories.

  1. Sycamore grit siltstone: informal member of Upper Devonian in north-central West Virginia

    SciTech Connect

    Cavallo, L.J. (West Virginia Univ., Morgantown (USA))

    1988-08-01

    The Upper Devonian Sycamore grit siltstone (an informal member of the Brallier Formation) was studied both in outcrop and subsurface. Outcrops consist of approximately 80 ft of thin to medium-bedded, brownish-gray, argillaceous siltstones and olive-gray shales. The Sycamore was presumably deposited by or associated with turbidity currents, because sedimentary structures include incomplete Bouma sequences and flute casts. Petrographic studies from outcrop sections reveal quartz, plagioclase, feldspar, and micas as the dominant framework grains; the matrix is composed of ductile grains and finer detrital material. Porosity is very low in these outcrop samples due to pore filling and grain coating by chlorite and hematite. The subsurface portion of the study was conducted over a 12-county area of north-central West Virginia, where the Sycamore occupies a stratigraphic position approximately 1,500 ft below the Benson sand and 800 ft above the Tully Limestone. Areally, the Sycamore appears as a series of submarine fans and attains its maximum thickness where two or more of these fans overlap. Near Weston, in central Lewis County, the Sycamore grit siltstone reaches a thickness of 90 ft and is a proven economic producer of natural gas when dually completed with shallower formations.

  2. Microstructural effects in abrasive wear. Second annual progress report, August 10, 1982-August 12, 1983

    SciTech Connect

    Kosel, T.H.

    1983-08-12

    Progress has been made in understanding the mechanisms of carbide removal during abrasion by quartz abrasive. In situ SEM scratch tests have demonstrated that carbide fracture is the controlling process in quartz abrasion of white cast irons, suggesting that carbide toughness is a critical parameter in controlling abrasion resistance. A study of surface recrystallization during abrasion has yielded definite evidence of the occurrence of recrystallization in pure Al. A program to investigate the effects of vanadium additions and heat treatments on the abrasion resistance of white cast iron indicate that optimum abrasion resistance as well as optimum spalling resistance may be obtained using a subcritical annealing heat treatment. A new study of the effect of abrasive particle size on abrasion in dual-phase alloys has demonstrated the opposite effect from that observed in single-phase alloys for quartz abrasive, whereas with Al/sub 2/O/sub 3/ particles, dual-phase and single-phase alloys behave more similarly.

  3. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a)...

  4. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a)...

  5. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010...

  6. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010...

  7. Resistance of dentin coating materials against abrasion by toothbrush.

    PubMed

    Gando, Iori; Ariyoshi, Meu; Ikeda, Masaomi; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    2013-01-01

    Thin-film coating of root dentin surface by all-in-one adhesives has been shown to be an effective option to prevent root surface caries. The purpose of this study was to investigate the wear resistance against toothbrush abrasion of two all-in-one coating materials; Shield Force (SF) and Hybrid Coat (HC). Bovine dentin surfaces were covered with one of the coating materials; SF or HC. After storage in water for 24 h, the testing surface was subjected to the toothbrush abrasion test up to 50,000 cycles either in water or toothpaste slurry. The remaining thickness of the coating material was measured using SEM. Toothpaste slurry significantly increased rate of tooth brush abrasion of the coating materials. While SF and HC wore at a similar pace under toothbrush abrasion, SF had a thicker coat and could protect dentin longer, up to 50,000 cycles. PMID:23370872

  8. 7 CFR 3201.66 - Cuts, burns, and abrasions ointments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ointments. (a) Definition. Products designed to aid in the healing and sanitizing of scratches, cuts, bruises, abrasions, sun damaged skin, tattoos, rashes and other skin conditions. (b) Minimum biobased content. The Federal preferred...

  9. Magnetic abrasive finishing of hardened AISI 52100 steel

    Microsoft Academic Search

    Rahul S. Mulik; Pulak M. Pandey

    2011-01-01

    Surface finish has a vital influence on functional properties such as wear resistance and power loss due to friction on most\\u000a of the engineering components. Magnetic abrasive finishing (MAF) is one of the advanced finishing process in which a surface\\u000a is finished by removing the material in the form of microchips by abrasive particles in the presence of magnetic field

  10. Red Imported Fire Ant (Hymenoptera: Formicidae) Control with a Corn Grit Bait of Fenoxycarb without Soybean Oil

    Microsoft Academic Search

    DAVID F. WILLIAMS; WILLIAM A. BANKS; ROBERT K. VANDER MEER; CLIFFORD S. LOFGREN

    The standard fenoxycarb fire ant bait formulation (Logic), composed of pregel defatted corn grits and soybean oil toxicant, was modified by eliminating the soybean oil. This formulation without soybean oil contained >2 times more fenoxycarb and was as effective as the standard bait formulation against laboratory colonies of red imported fire ant, Solenopsis invicta Buren. In field tests, the modified

  11. CLASSIFICATION OF DRY-MILLED MAIZE GRIT YIELD GROUPS USING QUADRATIC DISCRIMINANT ANALYSIS AND DECISION TREE ALGORITHM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetically and environmentally diverse collection of maize (Zea maize L.) samples were evaluated for physical properties and grit yield to help develop a standard set of criteria to identify grain best suited for dry milling. Application of principal component analysis reduced a set of approxima...

  12. Starch degradation and nutrition value improvement in corn grits by solid state fermentation technique with Coriolus versicolor.

    PubMed

    Huang, Mian; Zhang, Song

    2011-10-01

    The study was conducted to evaluate effect of Coriolus versicolor mycelia on degrading starch and improving nutrition value in corn grits through solid state fermentation technique. The results showed that using soybean meal as a nitrogen source, ?-amylase secreted from C. versicolor expressed 407.25U/g of activity, leading to 45.15% of starch degraded. The activity grew with fermentation time until the 15(th) day, after that the amylase was deactivated rapidly. An orthogonal experiment designed for the study illustrated that degradation rate of starch in corn grits attained to maximum, 50.51%, when 100g of corn grits, added 16g of soybean meal, were fermented by C. versicolor for 12 days, in an initial pH 5.5. After fermenting, compared to the nonfermented control, contents of amino acids, total sugar, crude fat and crude protein were increased by 21.00%, 38.45%, 55.56%, 69.15% respectively. The significant improvement of nutrition value in corn grits is probably attributed to the intense metabolism of C. versicolor. PMID:24031762

  13. Starch degradation and nutrition value improvement in corn grits by solid state fermentation technique with Coriolus versicolor

    PubMed Central

    Huang, Mian; Zhang, Song

    2011-01-01

    The study was conducted to evaluate effect of Coriolus versicolor mycelia on degrading starch and improving nutrition value in corn grits through solid state fermentation technique. The results showed that using soybean meal as a nitrogen source, ?-amylase secreted from C. versicolor expressed 407.25U/g of activity, leading to 45.15% of starch degraded. The activity grew with fermentation time until the 15th day, after that the amylase was deactivated rapidly. An orthogonal experiment designed for the study illustrated that degradation rate of starch in corn grits attained to maximum, 50.51%, when 100g of corn grits, added 16g of soybean meal, were fermented by C. versicolor for 12 days, in an initial pH 5.5. After fermenting, compared to the nonfermented control, contents of amino acids, total sugar, crude fat and crude protein were increased by 21.00%, 38.45%, 55.56%, 69.15% respectively. The significant improvement of nutrition value in corn grits is probably attributed to the intense metabolism of C. versicolor. PMID:24031762

  14. Application of data dependent systems approach for evaluation of fracture modes during a single-grit scratching

    Microsoft Academic Search

    Ghatu Subhash; Josh E. Loukus; Sudhakar M. Pandit

    2002-01-01

    Brittle fracture and the associated material removal mechanisms in model brittle materials were investigated using single-grit scratch experiments. The objective was to develop a fundamental understanding of the mechanisms of brittle material removal during machining (e.g., grinding) processes and mathematically describe the induced topological features. Initial experiments were conducted on metals and the ductile material removal response was captured in

  15. A modified ASTM G-75 abrasion test helps select candidate alloys for service in a corrosive and abrasive slurry

    SciTech Connect

    Corbett, R.A.; Morrison, W.S.; Jenkins, C.F. (Corrosion Testing Labs., Inc., Wilmington, DE (USA); Westinghouse Savannah River Co., Aiken, SC (USA))

    1989-01-01

    The design of a hazardous waste immobilization facility at the Savannah River Site (SRS) set material requirements for both abrasion resistance and corrosion resistance in process equipment. Standard ASTM slurry wear test G75 was modified to permit evaluation and comparison of abrasive resistance of candidate materials of construction in the laboratory. However, corrosion was found to contribute significantly to overall metal loss during the testing. Consequently, the abrasive slurry used for the testing was modified by adjusting its chemistry to include appropriate corrosive species. The Miller numbers obtained in the modified G75 Miller abrasion test are described. Pilot plant observations for Type 304L austenitic stainless steel were available. These data were used to generate a Morrison-Miller Ratio'' in order to determine anticipated field abrasion properties for other alloys. Hardness for many of the alloys fell in a narrow range about Rockwell B90, but performance varied significantly in response to slurry chemistry. This effect if synergistic may often be overlooked in the selection process, and it needs to be addressed. Some pilot plant testing of other alloys is essential to confirm the calculated abrasion rates and the approach of using the Morrison-Miller ratio. 6 refs., 3 figs., 5 tabs.

  16. Fatigue behavior of Ti6Al4V and 316 LVM blasted with ceramic particles of interest for medical devices.

    PubMed

    Barriuso, S; Chao, J; Jiménez, J A; García, S; González-Carrasco, J L

    2014-02-01

    Grit blasting is used as a cost-effective method to increase the surface roughness of metallic biomaterials, as Ti6Al4V and 316 LVM, to enhance the osteointegration, fixation and stability of implants. Samples of these two alloys were blasted by using alumina and zirconia particles, yielding rough (up to Ra~8?m) and nearly smooth (up to Ra~1?m) surfaces, respectively. In this work, we investigate the sub-surface induced microstructural effects and its correlation with the mechanical properties, with special emphasis in the fatigue behavior. Blasting with zirconia particles increases the fatigue resistance whereas the opposite effect is observed using alumina ones. As in a conventional shot penning process, the use of rounded zirconia particles for blasting led to the development of residual compressive stresses at the surface layer, without zones of stress concentrators. Alumina particles are harder and have an angular shape, which confers a higher capability to abrade the surface, but also a high rate of breaking down on impact. The higher roughness and the presence of a high amount of embedded alumina particles make the blasted alloy prone to crack nucleation. Interestingly, the beneficial or detrimental role of blasting is more intense for the Ti6Al4V alloy than for the 316 steel. It is proposed that this behavior is related to their different strain hardening exponents and the higher mass fraction of particles contaminating the surface. The low value of this exponent for the Ti6Al4V alloy justifies the expected low sub-surface hardening during the severe plastic deformation, enhancing its capability to soft during cyclic loading. PMID:24216310

  17. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.912 Underwater blasting. (a) A blaster shall conduct all blasting operations, and no shot shall be fired without his approval. (b) Loading tubes and...

  18. Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

    NASA Technical Reports Server (NTRS)

    2006-01-01

    During recent soil-brushing experiments, the rock abrasion tool on NASA's Mars Exploration Rover Spirit became covered with dust, as shown here. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface stratigraphy. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool. Designers of the rock abrasion tool at Honeybee Robotics and engineers at the Jet Propulsion Laboratory developed a plan to run the brush on the rock abrasion tool in reverse to dislodge the dirt and return the tool to normal operation. Subsequent communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

    Spirit acquired this approximately true-color image with the panoramic camera on the rover's 893rd sol, or Martian day (July 8, 2006). The image combines exposures taken through three of the camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers.

  19. Aeolian abrasion on Venus: Preliminary results from the Venus simulator

    NASA Technical Reports Server (NTRS)

    Marshall, J. R.; Greeley, Ronald; Tucker, D. W.; Pollack, J. B.

    1987-01-01

    The role of atmospheric pressure on aeolian abrasion was examined in the Venus Simulator with a constant temperature of 737 K. Both the rock target and the impactor were fine-grained basalt. The impactor was a 3 mm diameter angular particle chosen to represent a size of material that is entrainable by the dense Venusian atmosphere and potentially abrasive by virtue of its mass. It was projected at the target 10 to the 5 power times at a velocity of 0.7 m/s. The impactor showed a weight loss of approximately 1.2 x 10 to the -9 power gm per impact with the attrition occurring only at the edges. Results from scanning electron microscope analysis, profilometry, and weight measurement are summarized. It is concluded that particles can incur abrasion at Venusian temperatures even with low impact velocities expected for Venus.

  20. Study of Dominant Factors Affecting Cerchar Abrasivity Index

    NASA Astrophysics Data System (ADS)

    Rostami, Jamal; Ghasemi, Amireza; Alavi Gharahbagh, Ehsan; Dogruoz, Cihan; Dahl, Filip

    2014-09-01

    The Cerchar abrasion index is commonly used to represent rock abrasion for estimation of bit life and wear in various mining and tunneling applications. Although the test is simple and fast, there are some discrepancies in the test results related to the equipment used, condition of the rock surface, operator skills, and procedures used in conducting and measuring the wear surface. This paper focuses on the background of the test and examines the influence of various parameters on Cerchar testing including pin hardness, surface condition of specimens, petrographical and geomechanical properties, test speed, applied load, and method of measuring wear surface. Results of Cerchar tests on a set of rock specimens performed at different laboratories are presented to examine repeatability of the tests. In addition, the preliminary results of testing with a new device as a potential alternative testing system for rock abrasivity measurement are discussed.

  1. The BLAST experiment

    Microsoft Academic Search

    D. Hasell; T. Akdogan; R. Alarcon; W. Bertozzi; E. Booth; T. Botto; J. R. Calarco; B. Clasie; C. Crawford; A. Degrush; K. Dow; D. Dutta; M. Farkhondeh; R. Fatemi; O. Filoti; W. Franklin; H. Gao; E. Geis; S. Gilad; W. Hersman; M. Holtrop; E. Ihloff; P. Karpius; J. Kelsey; M. Kohl; H. Kolster; S. Krause; T. Lee; A. Maschinot; J. Matthews; K. McIlhany; N. Meitanis; R. Milner; J. Rapaport; R. Redwine; J. Seely; A. Sindile; S. Širca; T. Smith; S. Sobczynski; M. Tanguay; B. Tonguc; C. Tschalaer; E. Tsentalovich; W. Turchinetz; J. van der Laan; F. Wang; T. Wise; Y. Xiao; W. Xu; C. Zhang; Z. Zhou; V. Ziskin; T. Zwart

    2009-01-01

    The Bates large acceptance spectrometer toroid (BLAST) experiment was operated at the MIT-Bates Linear Accelerator Center from 2003 until 2005. The detector and experimental program were designed to study, in a systematic manner, the spin-dependent electromagnetic interaction in few-nucleon systems. As such the data will provide improved measurements for neutron, proton, and deuteron form factors. The data will also allow

  2. Concepts of blast hole pressure applied to blast design

    Microsoft Academic Search

    C. Cunningham

    2006-01-01

    Blast hole pressure is the starting point for many blast design calculations, but the way in which it is usually derived, from measured detonation velocity, indicates that more thought is needed as to its true meaning and implication. The general impression is given that the energy in the hole is defined by velocity of detonation (VoD), but this is rarely

  3. Identification of blast resistance genes for managing rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating diseases worldwide. In the present study, an international set of monogenic differentials carrying 24 major blast resistance (R) genes (Pia, Pib, Pii, Pik, Pik-h, Pik-m, Pik-p, Pik-s, Pish, Pit, Pita, Pita2,...

  4. The material and energy flow through the abrasive waterjet machining and recycling processes

    E-print Network

    Kurd, Michael Omar, 1982-

    2004-01-01

    The purpose of this thesis was to investigate the material and energy flow through the abrasive waterjet machine and the WARD recycling machine. The goal was to track all of the material, water, abrasive, energy, air, and ...

  5. Safety First Safety AlwaysSafety Last Using abrasive wheel equipment exposes you to many

    E-print Network

    Minnesota, University of

    Safety First Safety AlwaysSafety Last Using abrasive wheel equipment exposes you to many potential and strength and meet all manufacturer specifications. Abrasive Wheel Machinery and Tools Safety Tip #1

  6. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 ...SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512—Reflectorized Bicycle Wheel Rim Abrasion Test Device...

  7. Designing a low cost XY stage for abrasive water jet cutting

    E-print Network

    Abu Ibrahim, Fadi, 1980-

    2004-01-01

    This thesis guides the reader through the design of an inexpensive XY stage for abrasive water jet cutting machine starting with a set of functional requirements and ending with a product. Abrasive water jet cutting allows ...

  8. Field evidence of two-phase abrasion process

    NASA Astrophysics Data System (ADS)

    Miller, K. L.; Szabo, T.; Jerolmack, D. J.; Domokos, G.

    2013-12-01

    The rounded shape of river rocks is clear evidence that abrasion due to bed load transport is a significant agent for mass loss. Its contribution to downstream fining, however, is typically assumed to be negligible - as diminution trends may be explained solely by size-selective transport. A recent theory has predicted that pebble abrasion occurs in two well separated phases: in Phase 1, an intially-polyhedral pebble rounds to the shape of an inscribed ellipsoid without any change in axis dimensions; in Phase II, axis dimensions are slowly reduced. Importantly, Phase I abrasion means that an initially-blocky pebble may lose up to half its mass without any apparent change in 'size', which is only measured as the length of a single pebble axis by most field researchers. We hypothesize that field studies have significantly underestimated the importance of abrasion because they do not quantify pebble shape, and we set out to demonstrate that two-phase abrasion occurs in a natural stream. Our study examines downstream trends in pebble size and shape along a 10-km stretch of the Rio Mameyes within the Luquillo Critical Zone observatory, where volcaniclastic cobbles and boulders are transported by bed load at slopes up to 10%. The upper reaches of the stream consist of alluviated bedrock valleys that preclude sediment storage and thus minimize size-selective transport, which allows us to isolate the effects of abrasion. The lower 5 km is an alluvial river in which size-selective transport becomes operative. We quantified the shape and size of thousands of pebbles along the profile using hand and image-based techniques. The data provide the first field validation of two-phase abrasion; in the bedrock reaches, pebbles clearly evolve toward ellipsoids without any significant change in axis dimensions (rounding), while in the lower reaches pebbles slowly reduce their axis dimensions with little or no change in roundness. Results also show that shape metrics determined from two-dimensional (2D) imaging provide an adequate representation of the 3D evolution. In particular, the 2D curvature distribution is a sensitive metric of pebble shape, and is strongly related to the recently proposed 'equilibrium points' determined from 3D hand measurements. Although changes in pebble axis dimensions appear to be dominated by size-selective transport, shape data reveal that abrasion produces significant mass loss of pebbles. This mass loss affects both the mobility of the pebbles, and also produces substantial quantities of sand and silt that contribute to floodplain and ocean deposition downstream.

  9. Blast Coating of Superelastic NiTi Wire with PTFE to Enhance Wear Properties

    NASA Astrophysics Data System (ADS)

    Dunne, Conor F.; Roche, Kevin; Twomey, Barry; Hodgson, Darel; Stanton, Kenneth T.

    2015-04-01

    This work investigates the deposition of polytetrafluoroethylene (PTFE) onto a superelastic NiTi wire using an ambient temperature-coating technique known as CoBlast. The process utilises a stream of abrasive (Al2O3) and a coating medium (PTFE) sprayed simultaneously at the surface of the substrate. Superelastic NiTi wire is used in guidewire applications, and PTFE coatings are commonly applied to reduce damage to vessel walls during insertion and removal, and to aid in accurate positioning by minimising the force required to advance, retract or rotate the wire. The CoBlast coated wires were compared to wire treated with PTFE only. The coated samples were examined using variety of techniques: X-ray diffraction (XRD), microscopy, surface roughness, wear testing and flexural tests. The CoBlast coated samples had an adherent coating with a significant resistance to wear compared to the samples coated with PTFE only. The XRD revealed that the process gave rise to a stress-induced martensite phase in the NiTi which may enhance mechanical properties. The study indicates that the CoBlast process can be used to deposit thin adherent coatings of PTFE onto the surface of superelastic NiTi.

  10. A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage.

    PubMed

    Hines-Beard, Jessica; Marchetta, Jeffrey; Gordon, Sarah; Chaum, Edward; Geisert, Eldon E; Rex, Tonia S

    2012-06-01

    We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4 psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions. PMID:22504073

  11. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    Dr. M.A. Ebadian

    2000-01-13

    The purpose of the project is to increase the productivity and economics of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCB's and lead-base paint and provides worker and environmental protection by continuously recycling the blast media and the full containment of the dust generated in the process.

  12. Dynamic properties of blast furnaces

    Microsoft Academic Search

    V. I. Naboka; G. A. Polyanskii; A. P. Fomenko; N. V. Krutas

    2008-01-01

    In the present work, we investigate the dynamic properties of the blast-furnace process in terms of the two control signals (change in the ore load and change in the blast parameters), as well as random perturbing signals that change the composition of the furnace gas as a function of the ratio of direct and indirect ferrousoxide (FeO) reduction and the

  13. Grooving micro-abrasion of polyamide 11 coated carbon steel tubulars for downhole application

    Microsoft Academic Search

    J. O Bello; R. J. K Wood

    2003-01-01

    The tribological properties of polyamide 11 coated carbon steel injector tubulars are reported using a commercially available micro-abrasion tester, as a candidate method for assessing the abrasive wear of polymer coatings. Efforts have been made to reproduce the wear mechanisms found to predominate in field simulated conditions. The wireline-based tests produced severe grooving abrasion of the polyamide 11 coating resulting

  14. Computer assisted blast design and assessment tools

    SciTech Connect

    Cameron, A.R. [Golder Associates Ltd., Sudbury, Ontario (Canada); Kleine, T.H. [Golder Associates Inc., Seattle, WA (United States); Forsyth, W.W. [Golder Associates Ltd., Vancouver, British Columbia (Canada)

    1995-12-31

    In general the software required by a blast designer includes tools that graphically present blast designs (surface and underground), can analyze a design or predict its result, and can assess blasting results. As computers develop and computer literacy continues to rise the development of and use of such tools will spread. An example of the tools that are becoming available includes: Automatic blast pattern generation and underground ring design; blast design evaluation in terms of explosive distribution and detonation simulation; fragmentation prediction; blast vibration prediction and minimization; blast monitoring for assessment of dynamic performance; vibration measurement, display and signal processing; evaluation of blast results in terms of fragmentation; and risk and reliability based blast assessment. The authors have identified a set of criteria that are essential in choosing appropriate software blasting tools.

  15. A useful evacuation aid for intraoral air-abrasive devices.

    PubMed

    Liebenberg, W H

    1997-02-01

    Air-abrasive technology offers several advantages over conventional handpieces. Although modern high-speed evacuation systems result in limited powder accumulation, the microabrasive debris continues to be a major concern. This article highlights the need for rubber dam isolation and introduces a makeshift evacuation device fabricated from a plastic soft drink container. PMID:10332363

  16. Forces prediction during material deformation in abrasive flow machining

    Microsoft Academic Search

    V. K. Gorana; V. K. Jain; G. K. Lal

    2006-01-01

    To study the finishing mechanism of abrasive flow machining (AFM), theoretical model of forces acting on a single grain has been developed. An experimental research has been carried out by measuring the axial force, radial force and active grain density during the AFM process. Results obtained from theoretical model for grain–workpiece interaction during material deformation have been compared with the

  17. Parametric Effects on Particle Deposition in Abrasive Waterjet Surface Treatments

    Microsoft Academic Search

    D. Arola; C. L. Hall

    2004-01-01

    The abrasive waterjet (AWJ) has primarily been used for net-shape sectioning of engineering materials. In this study an AWJ was adopted for the surface treatment of commercially pure titanium (cpTi) and the contribution of treatment parameters to material removal and the deposition of particles within the substrate were examined. The surface texture and material removal rate were analyzed using conventional

  18. Abrasive water-jet cutting; remote hot cell application

    SciTech Connect

    Leist, K.J.; Funnell, G.J.

    1988-09-01

    In the process of selecting a failed equipment cut-up tool for the Process Facility Modifications (PFM) Project, a system using an Abrasive Water Jet (AWJ) was developed and tested for remote disassembly of failed equipment by the Westinghouse Hanford Company, PFM Mechanical Development Unit.

  19. Apparatus for producing abrasion resistant coke from brown coal briquets

    Microsoft Academic Search

    H. Dungs; H. Kersting; R. Kurtz; K. Lorenz; H. Weber

    1981-01-01

    A method of producing abrasion resistant coke from brown coal briquets in a shaft furnace comprises charging the coke briquets into the top of the furnace and removing coke from the bottom of the furnace while directing inert hot combustion gases into the furnace and through the briquets at a plurality of vertically spaced levels throughout the height of the

  20. Raising the resistance of mainline pump parts to hydraulic abrasion

    Microsoft Academic Search

    V. Ya. Belousov; V. V. Borisenko; Yu. V. Zhuravlev

    1988-01-01

    The authors investigate the diffusion coating of mainline petroleum pump surfaces with boron carbides and the subsequent hardness and abrasion resistance of the working surfaces based on the temperature of the treatment and the depth and concentration of the coating. Industrial testing on an NM 2500 x 230 centrifugal pump demonstrated an increase in service life by a factor of

  1. Characterization and prediction of abrasive wear of powder composite materials

    Microsoft Academic Search

    R. Veinthal; P. Kulu; J. Pirso; H. Käerdi

    2009-01-01

    Composite materials produced by powder metallurgy provide a solution in many engineering applications where materials with high abrasion and erosion resistance are required. The actual wear behaviour of the material is associated with many external factors (particle size, velocity, angularity, etc.) and intrinsic material properties (hardness, toughness, Young modulus, etc.). Hardness and toughness properties of such tribomaterials are highly dependent

  2. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Abrasive device and accessories. 872...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous...in § 872.9. If the device is not labeled or otherwise...of the quality system regulation in part 820 of this...

  3. Industrial cooling tower fan blade having abrasion resistant leading edge

    Microsoft Academic Search

    L. F. Burdick; S. E. Mayes

    1992-01-01

    This patent describes a glass fiber reinforced, synthetic resin fan blade for large diameter industrial water cooling tower fans, wherein the outer body portion of the blade is constructed of a thermoset resin and has upper and lower surfaces of which a part thereof define an elongated leading which would be subject to abrasion deterioration during use of the blade.

  4. PROTECTIVE EFFECT OF GREEN TEA ON DENTIN EROSION AND ABRASION

    PubMed Central

    Kato, Melissa Thiemi; Magalhăes, Ana Carolina; Rios, Daniela; Hannas, Angélica Reis; Attin, Thomas; Buzalaf, Marília Afonso Rabelo

    2009-01-01

    Objective: This in situ study evaluated the protective effect of green tea on dentin erosion (ERO) and erosion-abrasion (ABR). Material and methods: Ten volunteers wore intraoral palatal appliances with bovine dentin specimens subjected to ERO or ERO + toothbrushing abrasion performed immediately (ERO+I-ABR) or 30 min after erosion (ERO+30-min-ABR). During 2 experimental 5-day crossover phases, the volunteers rinsed with green tea or water (control, 1 min) between each erosive (5 min, cola drink) and abrasive challenge (30 s, toothbrushing), 4x/day. Dentin wear was measured by profilometry. Results: The green tea reduced the dentin wear significantly for all conditions compared to control. ERO+I-ABR led to significantly higher wear than ERO, but it was not significantly different from ERO+30-min-ABR. ERO+30-min-ABR provoked significant higher wear than ERO, only for the placebo treatment. Conclusions: From the results of the present study, it may be concluded that green tea reduces the dentin wear under erosive/abrasive conditions. PMID:20027426

  5. Innovative decontamination technology by abrasion in vibratory vessels

    SciTech Connect

    Fabbri, Silvio; Ilarri, Sergio [National Atomic Energy Commission - CNEA, Avda. del Libertador 8250, CP 1429, Ciudad Autonoma de Buenos Aires (Argentina)

    2007-07-01

    Available in abstract form only. Full text of publication follows: The possibility of using conventional vibratory vessel technology as a decontamination technique is the motivation for the development of this project. The objective is to explore the feasibility of applying the vibratory vessel technology for decontamination of radioactively-contaminated materials such as pipes and metal structures. The research and development of this technology was granted by the U.S. Department of Energy (DOE). Abrasion processes in vibratory vessels are widely used in the manufacture of metals, ceramics, and plastics. Samples to be treated, solid abrasive media and liquid media are set up into a vessel. Erosion results from the repeated impact of the abrasive particles on the surface of the body being treated. A liquid media, generally detergents or surfactants aid the abrasive action. The amount of material removed increases with the time of treatment. The design and construction of the machine were provided by Vibro, Argentina private company. Tests with radioactively-contaminated aluminum tubes and a stainless steel bar, were performed at laboratory level. Tests showed that it is possible to clean both the external and the internal surface of contaminated tubes. Results show a decontamination factor around 10 after the first 30 minutes of the cleaning time. (authors)

  6. 6/2/12 NCBI Blast:sbe vs human 1/770www.ncbi.nlm.nih.gov/blast/Blast.cgi

    E-print Network

    Hickman, Mark

    6/2/12 NCBI Blast:sbe vs human 1/770www.ncbi.nlm.nih.gov/blast/Blast.cgi Database Name Description Blast:sbe vs human 2/770www.ncbi.nlm.nih.gov/blast/Blast.cgi Legend for links to other resources: Uni

  7. SPECIFIC ENERGY AND SCRATCH HARDNESS OF GAMMA TITANIUM ALUMINIDES SUBJECTED TO SINGLE-GRIT PENDULUM SCRATCHING

    SciTech Connect

    Wang, Hong [ORNL; Lin, Hua-Tay [ORNL; Wereszczak, Andrew A [ORNL

    2006-01-01

    Two gamma titanium aluminides TiAls (Daido TiAl HIP and HOWMET TiAl) with fully lamellar structure but with different colony sizes were studied using a single-grit pendulum (rotational) scratch tester. The maximum depth of groove was ~ 0.07 mm and the scratch velocity used was ~ 1,000 mm/s. Normal and tangential forces were monitored during each scratch. The material removal mechanisms were examined using a scanning electronic microscope (SEM), and also measured by using a laser profilometer. Extensive thermal softening was observed. Sizable fractures were revealed in the transverse direction; however the role of these fractures in the chip formation depends on the microstructure of materials and the size of groove. The tribological properties were characterized by instantaneous specific energy and scratch hardness as related to the depth of groove. The overall response of materials can be effectively characterized by a two-parameter model, namely, HEM model and PSR model, even though the underlining material removal might be subjected to the different mechanisms. The TiAl with the larger colony or grain size exhibits a strong resistance to material loss or material removal (higher depth-independent specific energy) while exhibiting lower scratch hardness. The obtained depth-independent specific energy and scratch hardness can be used to screen the candidate materials depending on whether the application is sliding or impact dominant.

  8. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    1999-05-31

    The objective of this project is to improve the productivity and lower the expense of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCBs, and lead-based paint and provides worker protection by continuously recycling the material and dust for the decontamination tasks. The proposed work would increase the cleaning rate and provide safe and cost-effective decontamination of the DOE sites. This work focuses on redesigning and improving existing vacuum blasting technology including blast head nozzles, ergonomic handling of the blast head by reducing its weight; brush-ring design, vacuum level regulator, efficiency of the dust separator, and operational control sensors. The redesign is expected to enhance the productivity and economy of the vacuum blasting system by at least 50% over current vacuum blasting systems. There are three phases in the project. Phase I consists of developing and testing mathematical models. Phase II consists of pre-prototype design and fabrication and pre-prototype unit testing. Phase III consists of prototype design and field verification testing. In phase I, mathematical models are developed and analyzed for the nozzle, blast head, wind curtain, and dust separator, first as individual devices and then combined as an integrated model. This allows study of respective airflow and design parameters. The Contractor shall, based on the results of the mathematical modeling studies, design experimental models of the components and test these models. In addition, the Contractor shall develop sensors to detect the relationship of the blast head to the blast surfaces and controls to minimize the dependency on an operator's skill and judgment to obtain optimum positioning, as well as real-time characterization sensors to determine as the blast head is moving the depth to which coatings must be removed, thereby improving production and minimizing waste. In phase II, the Contractor shall design and construct a pre-prototype of the nozzle, blast head with wind curtain, sensors, and dust separator and test this system to assess the performance of the new design under controlled conditions at the contractor's facility. In phase III, the Contractor shall design and construct a prototype of the High Productivity Vacuum Blasting System, based on the results of the pre-prototype design and testing performed. This unit will be a full-scale prototype and will be tested at a designated Department of Energy (DOE) facility. Based on the results, the system performance, the productivity, and the economy of the improved vacuum blasting system will be evaluated.

  9. Centrifugal shot blast system

    SciTech Connect

    NONE

    1998-02-01

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997.

  10. Blasting casting to raise productivity

    SciTech Connect

    Pilshaw, S.R.

    1987-07-01

    Normally, surface mines employ draglines or truck and shovel systems to remove overburden. Blasting merely fragments and displaces the overburden enough to allow for easy digging. But during the past two decades, the effect of inflation and increased labor costs have encouraged unconventional methods of overburden removal. All of us are aware of the tremendous inflationary effects on costs of equipment, fuel, labor, interest, insurance, environmental compliance, etc. This has allowed the authors to take a new look at the use of explosives as an effective alternate method of overburden removal. This technique is known by several names, but basically blast casting or just casting best describes it. Other terms in vogue are explosive casting, controlled trajectory blasting, trajectory control blasting, and whatever terminology comes to mind.

  11. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2010-10-26

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  12. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2007-05-22

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  13. Blast-wave density measurements

    Microsoft Academic Search

    D. V. Ritzel

    1986-01-01

    Applications of a densitometer to obtain time-resolved data on the total density in blast-wave flows are described. A beta-source (promethium-147) is separated by a gap from a scintillator and a photomultiplier tube (PMT). Attenuation of the radiation beam by the passing blast wave is due to the total density in the gap volume during the wave passage. Signal conditioning and

  14. Nanometric Finishing on Biomedical Implants by Abrasive Flow Finishing

    NASA Astrophysics Data System (ADS)

    Subramanian, Kavithaa Thirumalai; Balashanmugam, Natchimuthu; Shashi Kumar, Panaghra Veeraiah

    2015-05-01

    Abrasive flow finishing (AFF) is a non-conventional finishing technique that offers better accuracy, efficiency, consistency, economy in finishing of complex/difficult to machine materials/components and provides the possibility of effective automation as aspired by the manufacturing sector. The present study describes the finishing of a hip joint made of ASTM grade Co-Cr alloy by Abrasive Flow Machining (AFM) process. The major input parameters of the AFF process were optimized for achieving nanometric finishing of the component. The roughness average (Ra) values were recorded during experimentation using surface roughness tester and the results are discussed in detail. The surface finished hip joints were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and residual stress analysis using X-Ray Diffraction (XRD). The discussion lays emphasis on the significance, efficacy and versatile nature of the AFF process in finishing of bio-medical implants.

  15. A physically-based abrasive wear model for composite materials

    SciTech Connect

    Lee, Gun Y.; Dharan, C.K.H.; Ritchie, Robert O.

    2001-05-01

    A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of the reinforcement is estimated by modeling the three primary wear mechanisms, specifically plowing, interfacial cracking and particle removal. Critical variables describing the role of the reinforcement, such as its relative size and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy matrix composite material.

  16. Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Fatemi, Navid S.; Wilt, David M.; Ferguson, Dale C.; Hoffman, Richard; Hill, Maria M.; Kaloyeros, Alain E.

    1996-01-01

    A series of metals was examined for suitability for the Wheel Abrasion Experiment, one of ten microrover experiments of the Mars Pathfinder Mission. The seven candidate metals were: Ag, Al, Au, Cu, Ni, Pt, and W. Thin films of candidate metals from 0.1 to 1.0 micrometer thick were deposited on black anodized aluminum coupons by e-beam and resistive evaporation and chemical vapor deposition. Optical, corrosion, abrasion, and adhesion criteria were used to select Al, Ni, and Pt. A description is given of the deposition and testing of thin films, followed by a presentation of experimental data and a brief discussion of follow-on testing and flight qualification.

  17. Blast From the Past

    NSDL National Science Digital Library

    A recently recovered deep-sea core supports theories that an asteroid collided with the earth 65 million years ago, around the time of the extinction of the dinosaurs. The Smithsonian Institution National Museum of Natural History's new site, Blast from the Past, contains details on this cataclysmic event. Colorful graphics provide conceptual illustrations of the asteroid impact and aftermath, accompanied by photographs of the deep-sea core. Text summaries, followed by bibliographic references, describe the asteroid hypothesis, the Cretaceous/Tertiary (K/T) boundary, and the utility of deep-sea cores. With links to other paleobiological sites and related museum exhibits, this site is a useful resource for those wanting to know more about fateful asteroid impacts.

  18. The BLAST experiment

    NASA Astrophysics Data System (ADS)

    Hasell, D.; Akdogan, T.; Alarcon, R.; Bertozzi, W.; Booth, E.; Botto, T.; Calarco, J. R.; Clasie, B.; Crawford, C.; DeGrush, A.; Dow, K.; Dutta, D.; Farkhondeh, M.; Fatemi, R.; Filoti, O.; Franklin, W.; Gao, H.; Geis, E.; Gilad, S.; Hersman, W.; Holtrop, M.; Ihloff, E.; Karpius, P.; Kelsey, J.; Kohl, M.; Kolster, H.; Krause, S.; Lee, T.; Maschinot, A.; Matthews, J.; McIlhany, K.; Meitanis, N.; Milner, R.; Rapaport, J.; Redwine, R.; Seely, J.; Shinozaki, A.; Sindile, A.; Širca, S.; Smith, T.; Sobczynski, S.; Tanguay, M.; Tonguc, B.; Tschalaer, C.; Tsentalovich, E.; Turchinetz, W.; van den Brand, J. F. J.; van der Laan, J.; Wang, F.; Wise, T.; Xiao, Y.; Xu, W.; Zhang, C.; Zhou, Z.; Ziskin, V.; Zwart, T.

    2009-05-01

    The Bates large acceptance spectrometer toroid (BLAST) experiment was operated at the MIT-Bates Linear Accelerator Center from 2003 until 2005. The detector and experimental program were designed to study, in a systematic manner, the spin-dependent electromagnetic interaction in few-nucleon systems. As such the data will provide improved measurements for neutron, proton, and deuteron form factors. The data will also allow details of the reaction mechanism, such as the role of final state interactions, pion production, and resonances to be studied. The experiment used: a longitudinally polarized electron beam stored in the South Hall Storage Ring; a highly polarized, isotopically pure, internal gas target of hydrogen or deuterium provided by an atomic beam source; and a symmetric, general purpose detector based on a toroidal spectrometer with tracking, time-of-flight, Cherenkov, and neutron detectors. Details of the experiment and operation are presented.

  19. A study of abrasive waterjet characteristics by CFD simulation

    Microsoft Academic Search

    H. Liu; J. Wang; N. Kelson; R. J. Brown

    2004-01-01

    Computational fluid dynamics (CFD) models for ultrahigh velocity waterjets and abrasive waterjets (AWJs) are established using the Fluent6 flow solver. Jet dynamic characteristics for the flow downstream from a very fine nozzle are then simulated under steady state, turbulent, two-phase and three-phase flow conditions. Water and particle velocities in a jet are obtained under different input and boundary conditions to

  20. Topographical anomaly on surfaces created by abrasive waterjet

    Microsoft Academic Search

    Sergej Hloch; Jan Valí?ek

    In the present study, real topographic function and maximal depth of neglected initial zone were analytically developed to\\u000a predict surface roughness on the top region of surfaces created by abrasive waterjet. An upper area of workpieces was analysed\\u000a in details. Experimentally created surfaces were measured by HOMMEL TESTER T8000 and non-contact profilometer Micro Prof FRT.\\u000a As an experimental material, stainless

  1. Optimum Path Planning of Robotic Free Abrasive Polishing Process

    Microsoft Academic Search

    Guangchao Han; Ming Sun

    2008-01-01

    In the rapid spray metal tooling, high efficient polishing process can improve the mold quality and shorten the lead time\\u000a of the rapid tool. The polishing of the tool is frequently carried out manually, and the introduction of robotic polishing\\u000a can minimize the production times and enhance the efficiency obviously. Robotic polishing process with free abrasive and soft\\u000a polishing tool

  2. Optimization of abrasive water jet cutting of ductile materials

    Microsoft Academic Search

    Asif Iqbal; Naeem U. Dar; Ghulam Hussain

    2011-01-01

    Full factorial design of experiments was developed in order to investigate the effects of jet pressure, abrasive mixing rate,\\u000a cutting feed, and plate thickness upon three response variables, surface finish of cutting wear zone, percentage proportion\\u000a of striation free area, and maximum width of cut. The set of sixteen experiments was performed on each of the following two\\u000a ductile materials:

  3. Experimental Investigations on Ice Bonded Abrasive Polishing of Copper Materials

    Microsoft Academic Search

    R. Mohan; N. Ramesh Babu

    2010-01-01

    In this article, an attempt is made to prepare an ice-bonded abrasive polishing (IBAP) tool, in situ, for ultrafine finishing of flat, Electrolytic Copper (EC)-grade copper specimen. Two different methods such as direct and layer-by-layer methods of freezing slurry were tried for preparation of the IBAP tool. Tools prepared by both these methods were characterized to analyze the distribution of

  4. Occlusive Dressings and the Healing of Standardized Abrasions

    PubMed Central

    Beam, Joel W

    2008-01-01

    Context: Acute skin trauma during sport participation, resulting in partial-thickness abrasions, is common. The limited investigations focusing on the acute wound environment and dressing techniques and the subsequent lack of evidence-based standards complicate clinical wound care decisions. Objective: To examine the effects of occlusive dressings on healing of standardized, partial-thickness abrasions. Design: Controlled, counterbalanced, repeated-measures design. Setting: University laboratory. Patients or Other Participants: Sixteen healthy women (n ?=? 10) and men (n ?=? 6). Intervention(s): Four standardized, partial-thickness abrasions were inflicted. Film, hydrogel, and hydrocolloid occlusive dressings and no dressing (control) were applied. Participants returned on postwound days 1, 3, 5, 7, 10, and 14 for digital imaging. Wound healing time was measured by change in wound contraction (cm2) and change in wound color (chromatic red) and luminance in red, green, and blue color values. Main Outcome Measure(s): Wound contraction, color (chromatic red), and luminance. Results: A day-by-dressing interaction was found for wound contraction, color, and luminance. Post hoc testing indicated that the film and hydrocolloid dressings produced greater wound contraction than the hydrogel and no dressing on days 7 and 10. Film, hydrogel, and hydrocolloid dressings also resulted in greater wound contraction than the control on day 14. Hydrocolloid dressings produced smaller measures of color and greater measures of luminance than no dressing on day 7. Film, hydrogel, and hydrocolloid dressings also resulted in smaller measures of color and greater measures of luminance compared with no dressing on days 10 and 14. Conclusions: When compared with the control (no dressing), the film, hydrogel, and hydrocolloid occlusive dressings were associated with a faster healing rate of partial-thickness abrasions across time measured by wound contraction, color, and luminance. Overall, these data indicate that occlusive dressings were more effective in healing than no dressing was. PMID:19030138

  5. Performance of the Light Trigger System in the Liquid Xenon Gamma-Ray Telescope LXeGRIT

    Microsoft Academic Search

    Uwe Oberlack; Elena Aprile; Alessandro Curioni; Karl-Ludwig Giboni

    2000-01-01

    LXeGRIT is a balloon-borne Compton telescope for MeV gamma-ray astrophysics,\\u000abased on a liquid xenon time projection chamber with charge and light readout.\\u000aThe energy and direction of an incident gamma-ray is reconstructed from the\\u000athree-dimensional locations and energy deposits of individual interactions\\u000ataking place in the homogeneous detector volume. While the charge signals\\u000aprovide energy information and X-Y positions,

  6. Abrasion of Candidate Spacesuit Fabrics by Simulated Lunar Dust

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Meador, Mary Ann; Rogers, Kerry J.; Sheehy, Brennan H.

    2009-01-01

    A protocol has been developed that produced the type of lunar soil abrasion damage observed on Apollo spacesuits. This protocol was then applied to four materials (Kevlar(Registered TradeMark), Vectran(Registered TradeMark), Orthofabric, and Tyvek(Registered TradeMark)) that are candidates for advanced spacesuits. Three of the four new candidate fabrics (all but Vectran(Registered TradeMark)) were effective at keeping the dust from penetrating to layers beneath. In the cases of Kevlar(Registered TradeMark) and Orthofabric this was accomplished by the addition of a silicone layer. In the case of Tyvek , the paper structure was dense enough to block dust transport. The least abrasive damage was suffered by the Tyvek(Registered TradeMark). This was thought to be due in large part to its non-woven paper structure. The woven structures were all abraded where the top of the weave was struck by the abrasive. Of these, the Orthofabric suffered the least wear, with both Vectran(Registered TradeMark) and Kevlar(Registered TradeMark) suffering considerably more extensive filament breakage.

  7. Modelling of blast loading on aboveground structures - II. Internal blast and ground shock

    Microsoft Academic Search

    F. B. A. Beshara

    1994-01-01

    Recent studies of the nature and structural effects of confined explosions, contact blast and explosion-induced ground shock are presented. High explosive blast is distinguished from that due to a gaseous deflagration. The effects of confinement and venting are considered in the evaluation of dynamic loads. Maxima for the initial internal blast pressure can be estimated from the scaled blast data

  8. The effect of hydrogen peroxide on polishing removal rate in CMP with various abrasives

    NASA Astrophysics Data System (ADS)

    Manivannan, R.; Ramanathan, S.

    2009-01-01

    The effect of hydrogen peroxide in chemical mechanical planarization slurries for shallow trench isolation was investigated. The various abrasives used in this study were ceria, silica, alumina, zirconia, titania, silicon carbide, and silicon nitride. Hydrogen peroxide suppresses the polishing of silicon dioxide and silicon nitride surfaces by ceria abrasives. The polishing performances of other abrasives were either unaffected or enhanced slightly with the addition of hydrogen peroxide. The ceria abrasives were treated with hydrogen peroxide, and the polishing of the work surfaces with the treated abrasive shows that the inhibiting action of hydrogen peroxide is reversible. It was found that the effect of hydrogen peroxide as an additive is a strong function of the nature of the abrasive particle.

  9. NCBI Handout Series | BLAST homepage & search pages | Last Update August 19, 2013 Contact: blast-help@ncbi.nlm.nih.gov BLAST Homepage and Selected Search Pages

    E-print Network

    Levin, Judith G.

    NCBI Handout Series | BLAST homepage & search pages | Last Update August 19, 2013 Contact: blast-help@ncbi.nlm.nih.gov/functions of selected search pages http://blast.ncbi.nlm.nih.gov National Center for Biotechnology Information present in a selected tar- get database. The NCBI BLAST homepage (http://blast.ncbi.nlm.nih.gov) provides

  10. Surface roughness prediction based on processing parameters in abrasive jet finishing with grinding wheel as restraint

    Microsoft Academic Search

    Li Changhe; Mao Weiping; Du Chao; Liu Zhanrui

    2010-01-01

    Based on the modeling and experiments concerning the surface roughness in abrasive jet finishing with grinding wheel as restraint, the effect of abrasive size, abrasive fluid concentration, machining cycles, wheel velocity and carrier fluid on machined surface quality was investigated. Surface grinder KP-36 was employed in a jet machining experiment conducted with W18Cr4V and 40Cr materials, profilometer TALYSURF was used

  11. New Experimental Rig to Investigate Abrasive–Corrosive Characteristics of Metals in Aqueous Media

    Microsoft Academic Search

    M. Salasi; G. B. Stachowiak; G. W. Stachowiak

    2010-01-01

    A new tribometer to investigate a conjoint effect of three-body abrasion and corrosion has been developed. In this design,\\u000a a flat wear sample is loaded against a rotating cylindrical disc counterface and the abrasive slurry is delivered to the contact\\u000a interface. Capabilities of the newly developed tribometer have been assessed through conducting abrasion–corrosion tests involving\\u000a simultaneous electrochemical measurements. In this

  12. Effect of coupling agent on abrasive wear behaviour of chopped jute fibre-reinforced polypropylene composites

    Microsoft Academic Search

    Navin Chand; U. K. Dwivedi

    2006-01-01

    In this paper, studies have been conducted to investigate the abrasive wear behaviour of jute fibre-reinforced polypropylene composites. Effect of addition of maleic anhydride-grafted polypropylene (MA-g-PP)-coupling agent by two different approach, sliding distance and load on abrasive wear performance of jute fibre–PP composites has been determined by using a SUGA abrasion tester. Use of coupling agent gives better wear resistance

  13. Transgressive stratigraphy, anoxia, and regional correlations within the late Precambrian Windermere grit of the southern Canadian Cordillera

    SciTech Connect

    Ross, G.M.; Murphy, D.C.

    1988-02-01

    The Windermere grit system in the southern Canadian Cordillera comprises the depositional record of a late Precambrian continental basin of uncertain tectonic affinity. Attempts to analyze the basin by means of these largely nonfossiliferous turbiditic rocks have been frustrated by a lack of chronostratigraphic marker units, a problem common in Precambrian sedimentary sequences. Stratigraphic analysis and regional mapping in the Cariboo Mountains (southeastern Canadian Cordillera) suggest that comparison of Precambrian sequences with Phanerozoic analogues holds promise for constructing chronologically significant sea-level lithostratigraphy. In the Cariboo and western Rocky mountains, a distinctive upward-thinning, dominantly pelitic succession (120 m thick) of rhythmic marble-silty pelite that is capped by a 20-m-thick carbonaceous sulfidic pelite represents a dramatic departure from sandy turbidite deposition and is interpreted as the depositional response of the turbidite system to eustatic sea-level rise. This marker unit appears to persist throughout Windermere grits in the southern Canadian Cordillera and, by analogy with well-constrained Phanerozoic examples of black shale deposition, is inferred to represent a synchronous basinwide highstand event. When analyzed within the context of black-shale depositional models, facies variations within the marker unit provide important constraints on basin shape, possibly water depth, and the magnitude of transcurrent fault movement in the southern Rocky Mountain trench.

  14. An Experimental Study on the Fabrication of Glass-based Acceleration Sensor Body Using Micro Powder Blasting Method

    PubMed Central

    Park, Dong-Sam; Yun, Dae-Jin; Cho, Myeong-Woo; Shin, Bong-Cheol

    2007-01-01

    This study investigated the feasibility of the micro powder blasting technique for the micro fabrication of sensor structures using the Pyrex glass to replace the existing silicon-based acceleration sensor fabrication processes. As the preliminary experiments, the effects of the blasting pressure, the mass flow rate of abrasive and the number of nozzle scanning times on erosion depth of the Pyrex and the soda lime glasses were examined. From the experimental results, optimal blasting conditions were selected for the Pyrex glass machining. The dimensions of the designed glass sensor was 1.7×1.7×0.6mm for the vibrating mass, and 2.9×0.7×0.2mm for the cantilever beam. The machining results showed that the dimensional errors of the machined glass sensor ranged from 3 ?m in minimum to 20 ?m in maximum. These results imply that the micro powder blasting method can be applied for the micromachining of glass-based acceleration sensors to replace the exiting method.

  15. MOLECULAR CONTROL OF THE RICE BLAST DISEASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by Magnaporthe grisea is a major constraint to rice production worldwide. The rice blast system is one of the best-characterized monocot model systems. The goal of this project is to understand molecular mechanisms of disease resistance using rice blast as a model system....

  16. Characterization of abrasion surfaces in rock shore environments of NW Spain

    NASA Astrophysics Data System (ADS)

    Feal-Pérez, Alejandra; Blanco-Chao, Ramón

    2013-04-01

    Despite the recent upsurge in rock coast research, many aspects of abrasion and their relationships to other processes remain poorly understood. In this paper, mechanisms subsumed under the general term abrasion were investigated at the beaches of Oia and Sartańa along the Galician coast of NW Spain, in particular at the micro- to meso-scale (mm-cm). Relationships between abrasion and mechanical rock strength served to explore feedbacks between weathering and abrasion on rock coasts, based on measurements of rock surface strength by means of the Equotip (Proceq) method, and stereomicroscope analyses of rock surfaces undergoing varying degrees of abrasion. The results suggest that (1) abrasion along near-vertical rock surfaces leads to a decrease in rock strength with elevation above the top of the basal sediment layer, (2) abrasion processes encompass two different modes, namely, the wave-induced sweeping and dragging of sand and gravel, and the projection of clasts against rock surfaces, each mode depending predominantly on the grain size of the abrasive agent, and (3) the two abrasion modes produce different rock surfaces whose roughness is strongly influenced by the properties of diverse minerals, in particular fracture and cleavage.

  17. Blast-wave density measurements

    NASA Astrophysics Data System (ADS)

    Ritzel, D. V.

    Applications of a densitometer to obtain time-resolved data on the total density in blast-wave flows are described. A beta-source (promethium-147) is separated by a gap from a scintillator and a photomultiplier tube (PMT). Attenuation of the radiation beam by the passing blast wave is due to the total density in the gap volume during the wave passage. Signal conditioning and filtering methods permit the system to output linearized data. Results are provided from use of the system to monitor blast waves emitted by detonation of a 10.7 m diameter fiberglass sphere containing 609 tons of ammonium nitrate/fuel oil at a 50.6 m height. Blast wave density data are provided for peak overpressure levels of 245, 172 and 70 kPa and distances of 183, 201 and 314 m from ground zero. Data resolution was of high enough quality to encourage efforts to discriminate dust and gasdynamic phenomena within passing blast waves.

  18. Tyre-blast injuries.

    PubMed

    Murty, O P

    2009-05-01

    A teenager college student was fatally injured by burst tyre air pressure while waiting on a public bus stand to catch a bus to reach her college at Kuala Lumpur. She accidentally came near the wheel while boarding when tube and tyre got burst .The air pressure had blown the girl in the air and she subsequently fell on a rough surface. The iron-locking rim of the wheel acted as a missile and hit the girl. She died on her way to the hospital. A medico-legal autopsy was performed which showed extensive injuries in the cranial and chest cavity. Head had large scalp laceration with diffuse separation and gaping from in the vault region; skull bones were fractured. Chest cavity had extensive rib fractures, lacerated lungs and haemo-thorax while externally there was no obvious injury. It requires intensive care management and screening of the victims. Tyre-blast injuries are not so common. This case exposes the hazard due to burst tyre. PMID:19329081

  19. Blast-Driven Hydrodynamic Instability

    NASA Astrophysics Data System (ADS)

    Henry de Frahan, Marc T.; Johnsen, Eric

    2013-11-01

    Accurate characterization of mixing from hydrodynamic instabilities, such as Richtmyer-Meshkov, Rayleigh-Taylor, and Kelvin-Helmholtz, is important to many multi-fluid applications, particularly, inertial confinement fusion, supernova collapse, and scramjet combustion. We investigate the dynamics of a perturbed interface between two fluids subjected to a planar blast wave. An initial point source explosion initiates a blast, which can be described as a shock front followed by a rarefaction wave. The interface, therefore, experiences an instantaneous acceleration (a pressure increase) followed by a gradual, time-dependent deceleration (a pressure decrease). The resulting interaction gives rise to Richtmyer-Meshkov and Rayleigh-Taylor growth, depending on the shock strength and blast profile. Using a high-order accurate numerical method that prevents pressure errors at interfaces when simulating variable specific heats ratios, we identify regimes in which one or the other instability dominates. Accurate characterization of mixing from hydrodynamic instabilities, such as Richtmyer-Meshkov, Rayleigh-Taylor, and Kelvin-Helmholtz, is important to many multi-fluid applications, particularly, inertial confinement fusion, supernova collapse, and scramjet combustion. We investigate the dynamics of a perturbed interface between two fluids subjected to a planar blast wave. An initial point source explosion initiates a blast, which can be described as a shock front followed by a rarefaction wave. The interface, therefore, experiences an instantaneous acceleration (a pressure increase) followed by a gradual, time-dependent deceleration (a pressure decrease). The resulting interaction gives rise to Richtmyer-Meshkov and Rayleigh-Taylor growth, depending on the shock strength and blast profile. Using a high-order accurate numerical method that prevents pressure errors at interfaces when simulating variable specific heats ratios, we identify regimes in which one or the other instability dominates. This research was supported by the DOE NNSA/ASC under the predictive Science Academic Alliance Program by Grant No. DEFC52-08NA28616.

  20. Standard Test Method for Abrasive Wear Resistance of Cemented

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the determination of abrasive wear resistance of cemented carbides. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units are in parentheses and may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Porcine Head Response to Blast

    PubMed Central

    Shridharani, Jay K.; Wood, Garrett W.; Panzer, Matthew B.; Capehart, Bruce P.; Nyein, Michelle K.; Radovitzky, Raul A.; Bass, Cameron R. ‘Dale’

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740?kPa peak incident overpressure with scaled durations from 1.3 to 6.9?ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30?s and the remaining two recovered within 8?min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390?kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830?kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2?=?0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are presented to provide experimental data for computer model validation. PMID:22586417

  2. Community response to blast noise

    NASA Astrophysics Data System (ADS)

    Nykaza, Edward T.; Pater, Larry L.; Fidell, Sanford; Schomer, Paul

    2005-09-01

    Although community response to impulsive noise from military operations is usually discussed for NEPA-related purposes in terms of the prevalence of annoyance, it is managed on a local, daily basis in terms of numbers of recent complaints. Reconciling blast noise complaint rates with the annoyance predicted by dosage-effect analysis would be of considerable benefit to the Army, since it would provide insight into the dynamics of community reaction to this distinctive form of noise exposure, and put its assessment and management on a common footing. This paper describes a systematic approach to the challenges of quantifying community reaction to blast noise. [Work supported by ERDC-CERL.

  3. Nucleon Form Factors from BLAST

    NASA Astrophysics Data System (ADS)

    Kohl, Michael

    2009-08-01

    The BLAST (Bates Large Acceptance Spectrometer Toroid) experiment has been carried out at the MIT-Bates Linear Accelerator Center to study spin-dependent electron scattering from protons and deuterons with small systematic uncertainties. The experiment used a longitudinally polarized, intense electron beam stored in the Bates South Hall Ring in combination with isotopically pure, highly-polarized internal targets of polarized hydrogen and vector- and tensor-polarized deuterium from an atomic beam source. The BLAST data have been used to extract precise results for the elastic form factor ratios GE/GM of the proton and the neutron at low momentum transfer.

  4. Nucleon Form Factors from BLAST

    SciTech Connect

    Kohl, Michael [Hampton University, Hampton, VA 23668, USA and Jefferson Lab, Newport News, VA 23606 (United States)

    2009-08-04

    The BLAST (Bates Large Acceptance Spectrometer Toroid) experiment has been carried out at the MIT-Bates Linear Accelerator Center to study spin-dependent electron scattering from protons and deuterons with small systematic uncertainties. The experiment used a longitudinally polarized, intense electron beam stored in the Bates South Hall Ring in combination with isotopically pure, highly-polarized internal targets of polarized hydrogen and vector- and tensor-polarized deuterium from an atomic beam source. The BLAST data have been used to extract precise results for the elastic form factor ratios G{sub E}/G{sub M} of the proton and the neutron at low momentum transfer.

  5. Effect of mechanical abrasion on the viability, disruption and germination of spores of Bacillus subtilis

    PubMed Central

    Jones, C.A.; Padula, N.L.; Setlow, P.

    2005-01-01

    Aims To elucidate the factors influencing the sensitivity of Bacillus subtilis spores to killing and disruption by mechanical abrasion, and the mechanism of stimulation of spore germination by abrasion. Methods and Results Spores of B. subtilis strains were abraded by shaking with glass beads in liquid or the dry state, and spore killing, disruption and germination were determined. Dormant spores were more resistant to killing and disruption by abrasion than were growing cells or germinated spores. However, dormant spores of the wild-type strain with or without most coat proteins removed, spores of strains with mutations causing spore coat defects, spores lacking their large depot of dipicolinic acid (DPA) and spores with defects in the germination process exhibited essentially identical rates of killing and disruption by abrasion. When spores lacking all nutrient germinant receptors were enumerated by plating directly on nutrient medium, abrasion increased the plating efficiency of these spores before killing them. Spores lacking all nutrient receptors and either of the two redundant cortex-lytic enzymes behaved similarly in this regard, but the plating efficiency of spores lacking both cortex-lytic enzymes was not stimulated by abrasion. Conclusions Dormant spores are more resistant to killing and disruption by abrasion than are growing cells or germinated spores, and neither the complete coats nor DPA are important in spore resistance to such treatments. Germination is not essential for spore killing by abrasion, although abrasion can trigger spore germination by activation of either of the spore’s cortex-lytic enzymes. Significance and Importance This work provides new insight into the mechanisms of the killing, disruption and germination of spores by abrasion and makes the surprising finding that at least much of the spore coat is not important in spore resistance to abrasion. PMID:16313421

  6. Evidence for Martian electrostatic charging and abrasive wheel wear from the Wheel Abrasion Experiment on the Pathfinder Sojourner rover

    NASA Astrophysics Data System (ADS)

    Ferguson, Dale C.; Kolecki, Joseph C.; Siebert, Mark W.; Wilt, David M.; Matijevic, Jacob R.

    1999-04-01

    The Wheel Abrasion Experiment (WAE) on the Mars Pathfinder rover was designed to find out how abrasive the Martian dust would be on strips of pure metals attached to one of the wheels. A specially modified wheel, with 15 thin film samples (five each of three different metals), specularly reflected sunlight to a photovoltaic sensor. When the wheel was rotated to present the different sample surfaces to the sensor, the resulting signal was interpreted in terms of dust adhesion and abrasive wear. Many data sequences were obtained. Ground tests of similar wheels in a simulated Martian environment showed that static charging levels of 100-300 V could be expected. To prevent the possibility of Paschen discharge in the low-pressure Martian atmosphere, charge dissipation points were added to the Sojourner rover and were shown in ground tests to keep charging levels at 80 V or less. Nevertheless, significant dust accumulations on Sojourner's wheels may be interpreted as evidence for electrostatic charging. Simple considerations of the expected maximum level of charging and electrostatic dust adhesion lead to an estimate for the size of the adhering dust grains. From the WAE data, it is hypothesized that the photoelectric effect is the most important mechanism for slow discharge in Martian daylight. Sensor signals obtained late in the Pathfinder mission show that significant wheel wear was seen on the metal wheel strips, with the most wear on the thinnest aluminum samples and the least on the thickest nickel and platinum samples. An estimate is made of the reflectance of the adhering Martian dust. The depth of dig of the WAE wheel shows that the dust is in some places very loose and in others tightly packed. Finally, comparison of the WAE results with ground test results makes possible a comparison of the Martian soil with mineral grain types and sizes found on Earth and show that the Martian dust is fine-grained and of limited hardness.

  7. Cotton Seedling Injury and Recovery from Wind Blown Sand Abrasion: I. Duration of Exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of acres of crops are exposed to wind blown sand abrasion injury each year and in many instances the damage is thought to be sufficiently severe to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton seedlings. Seedlings of...

  8. The effect of footwear sole abrasion on the coefficient of friction on melting and hard ice

    Microsoft Academic Search

    Chuansi Gao; John Abeysekera; Mikko Hirvonen; Carita Aschan

    2003-01-01

    Footwear sole wear by natural use or artificial abrasion either increases or decreases slip resistance on floors with and without lubricant. The objectives of this paper were to study the effect of footwear sole abrasive wear on slip resistance on ice with respect to temperature, and to compare the slip resistance of abraded soles on melting and hard ice with

  9. Flexural fatigue and surface abrasion of Kevlar-29 and other high-modulus fibres

    Microsoft Academic Search

    J. W. S. Hearle; B. S. Wong

    1977-01-01

    This investigation deals with some flexural fatigue and abrasion studies of Kevlar-29, glass and carbon fibres. The test methods included in the study are fatigue by pure flexing, buckling and rotation over a wire, and abrasion by rubbing against a rotating rod. Kevlar-29 fibres were found to perform well in these tests because they could survive the relatively high bending

  10. A Material Removal Model for CMP Based on the Contact Mechanics of Pad, Abrasives, and Wafer

    E-print Network

    Müftü, Sinan

    A Material Removal Model for CMP Based on the Contact Mechanics of Pad, Abrasives, and Wafer Dinçer, Massachusetts 02115, USA Applied pressure in chemical mechanical polishing CMP is shared by the two-body pad­wafer and the three-body pad­abrasive­ wafer contacts. The fraction of applied pressure transferred through

  11. Abrasive wear behavior of particle reinforced ultrahigh molecular weight polyethylene composites

    Microsoft Academic Search

    Chaozong Liu; Luquan Ren; R. D. Arnell; Jin Tong

    1999-01-01

    This paper, based on orthogonal experimental design method, reports the results of abrasive wear investigations of various composites of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with quartz powder rubbed against abrasive papers under dry conditions. The main purpose was to study the influence of such parameters such as filler particle size, load, sliding speed and abrading particle size on the

  12. Effect of Source of Fly Ash on Abrasion Resistance of Concrete

    E-print Network

    Wisconsin-Milwaukee, University of

    Effect of Source of Fly Ash on Abrasion Resistance of Concrete Tarun R. Naik1 ; Shiw S. Singh2 and amount of fly ash on abrasion resistance of concrete. A reference concrete was proportioned to have a 28 in producing the concrete mixtures. The water to cementitious materials ratio was kept constant at 0.30 for all

  13. Mass loss from abrasion on ogive-nose steel projectiles that penetrate concrete targets

    Microsoft Academic Search

    S. A. Silling; M. J. Forrestal

    2007-01-01

    We developed an abrasion model that predicts mass loss and change in nose shape for steel projectiles that penetrate concrete targets. Mass loss data from four sets of experiments with two ogive-nose projectile geometries and concrete targets with limestone and quartz aggregates were used to develop the abrasion model. We plotted post-test mass loss versus initial kinetic energy and found

  14. Effect of Abrasion on Protective Properties of Polyester and Cotton\\/Polyester Blend Fabrics

    Microsoft Academic Search

    A. Shaw; Y. J. Lin; E. Pfeil

    1996-01-01

    ®finish (fluoroalkyl methacrylate polymer) drastically reduced the sorption and penetration of pesticide through cotton, polyester, and cotton polyester blend fabrics (Shaw, 1992). As surface properties change due to abrasion, the level of protection provided by “worn” fabrics against pesticides may change. This study was conducted to determine the effect of surface abrasion on the sorption and penetration of pesticide through

  15. On the residual stress field induced by a scratching round abrasive grain

    Microsoft Academic Search

    G. Kermouche; J. Rech; H. Hamdi; J. M. Bergheau

    2010-01-01

    Most of superfinishing processes are based on the action of abrasive grains scratching the surface of a workpiece. These processes are known to improve the surface texture but they also modify the surface integrity, and thus the durability of engineering parts. In this paper, the residual stress field induced by the scratch of a single round abrasive grain is investigated

  16. Effect of canopy leaf distribution on sand transport and abrasion energy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During times when crop canopies are short or sparse, wind erosion can uncover plant roots, deplete the soil resource, and damage plants by abrasion and desiccation. Few studies have considered the effects of position and number of leaves on sand transport and the distribution of the sand abrasion en...

  17. Abrasion Resistant Coating and Method of making the same

    SciTech Connect

    Sordelet, Daniel J.; Besser, Matthew F.

    1999-06-25

    An abrasion resistant coating is created by adding a ductile phase to a brittle matrix phase during spray coating where an Al-Cu-Fe quasicrystalline phase (brittle matrix) and an FeAl intermetallic (ductile phase) are combined. This composite coating produces a coating mostly of quasicrystal phase and an inter-splat layer of the FeAl phase to help reduce porosity and cracking within the coating. Coatings are prepared by plasma spraying unblended and blended quasicrystal and intermetallic powders. The blended powders contain 1, 5, 10 and 20 volume percent of the intermetallic powders. The unblended powders are either 100 volume percent quasicrystalline or 100 volume percent intermetallic; these unblended powders were studied for comparison to the others. Sufficient ductile phase should be added to the brittle matrix to transform abrasive wear mode from brittle fracture to plastic deformation, while at the same time the hardness of the composite should not be reduced below that of the original brittle phase material.

  18. Air abrasion experiments in U-Pb dating of zircon

    USGS Publications Warehouse

    Goldich, S.S.; Fischer, L.B.

    1986-01-01

    Air abrasion of zircon grains can remove metamict material that has lost radiogenic Pb and zircon overgrowths that were added during younger events and thereby improve the precision of the age measurements and permit closer estimates of the original age. Age discordance that resulted from a single disturbance of the U-Pb isotopic decay systems, as had been demonstrated by T.E. Krogh, can be considerably reduced, and, under favorable conditions, the ages brought into concordancy. Two or more events complicate the U-Pb systematics, but a series of abrasion experiments can be helpful in deciphering the geologic history and in arriving at a useful interpretation of the probable times of origin and disturbances. In east-central Minnesota, U.S.A., Penokean tonalite gneiss is dated at 1869 ?? 5 Ma, and sheared granite gneiss is shown to have been a high-level granite intrusion at 1982 ?? 5 Ma in the McGrath Gneiss precursor. Tonalite gneiss and a mafic granodiorite in the Rainy Lake area, Ontario, Canada, are dated at 2736 ?? 16 and 2682 ?? 4 Ma, respectively. The tonalitic phase of the Morton Gneiss, southwestern Minnesota, is dated at 3662 ?? 42 Ma. ?? 1986.

  19. Rice blast disease in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is an important agricultural commodity in Texas, with an economic impact of more than $1 billion annually. Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases in rice. Texas Rice Belt provides a warm, humid climate favorable for the infection and reproduction of M....

  20. Community response to blast noise

    Microsoft Academic Search

    Edward T. Nykaza; Larry L. Pater; Sanford Fidell; Paul Schomer

    2005-01-01

    Although community response to impulsive noise from military operations is usually discussed for NEPA-related purposes in terms of the prevalence of annoyance, it is managed on a local, daily basis in terms of numbers of recent complaints. Reconciling blast noise complaint rates with the annoyance predicted by dosage-effect analysis would be of considerable benefit to the Army, since it would

  1. Red imported fire ant (Hymenoptera: Formicidae) control with a corn grit bait of fenoxycarb without soybean oil.

    PubMed

    Williams, D F; Banks, W A; Vander Meer, R K; Lofgren, C S

    1991-06-01

    The standard fenoxycarb fire ant bait formulation (Logic), composed of pregel defatted corn grits and soybean oil toxicant, was modified by eliminating the soybean oil. This formulation without soybean oil contained greater than 2 times more fenoxycarb and was as effective as the standard bait formulation against laboratory colonies of red imported fire ant, Solenopsis invicta Buren. In field tests, the modified and standard baits were equally effective in controlling fire ants after 6, 12, and 18 wk. Individual worker ants obtained from plots treated with fenoxycarb baits without soybean oil had greater than 47 times less fenoxycarb than did workers from the plots treated with the standard fenoxycarb baits containing soybean oil. PMID:1885843

  2. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

  3. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

  4. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

  5. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

  6. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

  7. Self-traveling robotic system for autonomous abrasive blast cleaning in double-hulled structures of ships

    E-print Network

    Kim, Jongwon

    of ships Donghun Lee a, , Namkuk Ku b , Tea-Wan Kim b , Kyu-Yeul Lee b , Jongwon Kim a , Sooho Kim c instability of the robot platform. Proposed robotic platform, will bring great benefits to ship yard after midnight on March 24, 1989, the 987-foot tank vessel Exxon Valdez, of the Exxon shipping company

  8. Modelling of blast loading on aboveground structures - I. General phenomenology and external blast

    Microsoft Academic Search

    F. B. A. Beshara

    1994-01-01

    The paper is concerned with the prediction of dynamic effects of unconfined explosions needed for the structural analysis of blast-loaded aboveground structures. The basic features of the explosion and blast wave phenomena are presented along with a discussion of TNT equivalency and blast scaling laws. The characteristics of incident overpressure loading due to atomic weapons, conventional high explosives and unconfined

  9. Photographs of Blast Effects on Structures

    NSDL National Science Digital Library

    Christopher Griffith

    This photograph collection shows a wood-frame house located 1,100 meters from ground zero, exposed to a nuclear blast at the Nevada Test Site. The test was Upshot-Knothole Annie, a 16 Kt tower shot, on March 17, 1953. Exposure to thermal radiation was 25 cal/cm2, about one-quarter of that experienced at ground zero in Hiroshima. The blast over pressure was 5 psi, and the blast wave created surface winds of 160 mph.

  10. Fatigue Testing of Abrasive Water Jet Cut Titanium

    SciTech Connect

    Hovanski, Yuri; Dahl, Michael E.; Williford, Ralph E.

    2009-06-08

    Battelle Memorial Institute as part of its U.S. Department of Energy (USDOE) Contract No. DE-AC05-76RL01830 to operate the Pacific Northwest National Laboratory (PNNL) provides technology assistance to qualifying small businesses in association with a Technology Assistance Program (TAP). Qualifying companies are eligible to receive a set quantity of labor associated with specific technical assistance. Having applied for a TAP agreement to assist with fatigue characterization of Abrasive Water Jet (AWJ) cut titanium specimens, the OMAX Corporation was awarded TAP agreement 09-02. This program was specified to cover dynamic testing and analysis of fatigue specimens cut from titanium alloy Ti-6%Al-4%V via AWJ technologies. In association with the TAP agreement, a best effort agreement was made to characterize fatigue specimens based on test conditions supplied by OMAX.

  11. Estimating rock compressive strength from Rock Abrasion Tool (RAT) grinds

    NASA Astrophysics Data System (ADS)

    Thomson, B. J.; Bridges, N. T.; Cohen, J.; Hurowitz, J. A.; Lennon, A.; Paulsen, G.; Zacny, K.

    2013-06-01

    Each Mars Exploration Rover carries a Rock Abrasion Tool (RAT) whose intended use was to abrade the outer surfaces of rocks to expose more pristine material. Motor currents drawn by the RAT motors are related to the strength and hardness of rock surfaces undergoing abrasion, and these data can be used to infer more about a target rock's physical properties. However, no calibration of the RAT exists. Here, we attempt to derive an empirical correlation using an assemblage of terrestrial rocks and apply this correlation to data returned by the rover Spirit. The results demonstrate a positive correlation between rock strength and RAT grind energy for rocks with compressive strengths less than about 150 MPa, a category that includes all but the strongest intact rocks. Applying this correlation to rocks abraded by Spirit's RAT, the results indicate a large divide in strength between more competent basaltic rocks encountered in the plains of Gusev crater (Adirondack-class rocks) and the weaker variety of rock types measured in the Columbia Hills. Adirondack-class rocks have estimated compressive strengths in the range of 70-130 MPa and are significantly less strong than fresh terrestrial basalts; this may be indicative of a degree of weathering-induced weakening. Rock types in the Columbia Hills (Wishstone, Watchtower, Clovis, and Peace class) all have compressive strengths <50 MPa and are consistent with impactites or volcanoclastic materials. In general, when considered alongside chemical, spectral, and rock textural data, these inferred compressive strength results help inform our understanding of rock origins and modification history.

  12. Linear abrasion of a titanium superhydrophobic surface prepared by ultrafast laser microtexturing

    NASA Astrophysics Data System (ADS)

    Steele, Adam; Nayak, Barada K.; Davis, Alexander; Gupta, Mool C.; Loth, Eric

    2013-11-01

    A novel method of fabricating titanium superhydrophobic surfaces by ultrafast laser irradiation is reported. The ultrafast laser irradiation creates self-organized microstructure superimposed with nano-scale roughness, after which a fluoropolymer coating is applied to lower the surface energy of the textured surface and achieve superhydrophobicity. The focus of this study is to investigate abrasion effects on this mechanically durable superhydrophobic surface. The mechanical durability is analyzed with linear abrasion testing and microscopy imaging. Linear abrasion tests indicate that these surfaces can resist complete microstructure failure up to 200 abrasion cycles and avoid droplet pinning up to ten abrasion cycles at 108.4 kPa applied pressure, which roughly corresponds to moderate to heavy sanding or rubbing in the presence of abrasive particles. The wear mechanisms are also investigated and the primary mechanism for this system is shown to be abrasive wear with fatigue by repeated plowing. Although these results demonstrate an advancement in mechanical durability over the majority of existing superhydrophobic surfaces, it exemplifies the challenge in creating superhydrophobic surfaces with suitable mechanical durability for harsh applications, even when using titanium.

  13. Relationships Between Abrasive Wear, Hardness, and Surface Grinding Characteristics of Titanium-Based Metal Matrix Composites

    SciTech Connect

    Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    The objective of this work was to support the development of grinding models for titanium metal-matrix composites (MMCs) by investigating possible relationships between their indentation hardness, low-stress belt abrasion, high-stress belt abrasion, and the surface grinding characteristics. Three Ti-based particulate composites were tested and compared with the popular titanium alloy Ti-6Al-4V. The three composites were a Ti-6Al-4V-based MMC with 5% TiB{sub 2} particles, a Ti-6Al-4V MMC with 10% TiC particles, and a Ti-6Al-4V/Ti-7.5%W binary alloy matrix that contained 7.5% TiC particles. Two types of belt abrasion tests were used: (a) a modified ASTM G164 low-stress loop abrasion test, and (b) a higher-stress test developed to quantify the grindability of ceramics. Results were correlated with G-ratios (ratio of stock removed to abrasives consumed) obtained from an instrumented surface grinder. Brinell hardness correlated better with abrasion characteristics than microindentation or scratch hardness. Wear volumes from low-stress and high-stress abrasive belt tests were related by a second-degree polynomial. Grindability numbers correlated with hard particle content but were also matrix-dependent.

  14. Microstructural effects in abrasive wear. Third annual progress report, August 12, 1983-August 14, 1984

    SciTech Connect

    Kosel, T.H.

    1984-08-14

    The two major goals of the project are to improve our understanding of the mechanisms of carbide removal and of the role of matrix properties in abrasion. In the area of carbide removal mechanisms, progress this year has included completion of the fixed-depth scratch test apparatus and its use to demonstrate the occurrence of gross carbide cracking under fixed-depth conditions; comparable cracking does not occur under fixed-load conditions at a similar mean load. A high-stress abrasion system has been constructed and tested which will facilitate studies of abrasion under conditions similar to those produced by the fixed-depth scratch test system. Analysis of the work on the size effect in abrasion of dual-phase alloys has been completed. The largest single item in this year's proposed work in a study of the abrasion resistance and mechanisms of material removal in model alloys having second-phase particles (SPP's) with varying fracture properties. In the area of the effects of matrix properties on abrasion, the majority of the effort this year has centered on transmission electron microscopy of the subsurface deformation microstructures developed during abrasion.

  15. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    2001-08-31

    The Department of Energy (DOE) needs improved technologies to decontaminate large areas of both concrete and steel surfaces. The technology should have high operational efficiency, minimize exposures to workers, and produce low levels of secondary waste. In order to meet the DOE's needs, an applied research and development project for the improvement of a current decontamination technology, Vacuum Blasting, is proposed. The objective of this project is to improve the productivity and lower the expense of the existing vacuum blasting technology which has been widely used in DOE sites for removing radioactive contamination, PCBs, and lead-based paint. The proposed work would increase the productivity rate and provide safe and cost-effective decontamination of the DOE sites.

  16. Laboratory blast wave driven instabilities

    NASA Astrophysics Data System (ADS)

    Kuranz, Carolyn

    2008-11-01

    This presentation discusses experiments involving the evolution of hydrodynamic instabilities in the laboratory under high-energy-density (HED) conditions. These instabilities are driven by blast waves, which occur following a sudden, finite release of energy, and consist of a shock front followed by a rarefaction wave. When a blast wave crosses an interface with a decrease in density, hydrodynamic instabilities will develop. Instabilities evolving under HED conditions are relevant to astrophysics. These experiments include target materials scaled in density to the He/H layer in SN1987A. About 5 kJ of laser energy from the Omega Laser facility irradiates a 150 ?m plastic layer that is followed by a low-density foam layer. A blast wave structure similar to those in supernovae is created in the plastic layer. The blast wave crosses an interface having a 2D or 3D sinusoidal structure that serves as a seed perturbation for hydrodynamic instabilities. This produces unstable growth dominated by the Rayleigh-Taylor (RT) instability in the nonlinear regime. We have detected the interface structure under these conditions using x-ray backlighting. Recent advances in our diagnostic techniques have greatly improved the resolution of our x-ray radiographic images. Under certain conditions, the improved images show some mass extending beyond the RT spike and penetrating further than previously observed or predicted by current simulations. The observed effect is potentially of great importance as a source of mass transport to places not anticipated by current theory and simulation. I will discuss the amount of mass in these spike extensions, the associated uncertainties, and hypotheses regarding their origin We also plan to show comparisons of experiments using single mode and multimode as well as 2D and 3D initial conditions. This work is sponsored by DOE/NNSA Research Grants DE-FG52-07NA28058 (Stewardship Sciences Academic Alliances) and DE-FG52-04NA00064 (National Laser User Facility).

  17. Nucleon Form Factors from BLAST

    Microsoft Academic Search

    Michael Kohl

    2009-01-01

    The BLAST (Bates Large Acceptance Spectrometer Toroid) experiment has been carried out at the MIT-Bates Linear Accelerator Center to study spin-dependent electron scattering from protons and deuterons with small systematic uncertainties. The experiment used a longitudinally polarized, intense electron beam stored in the Bates South Hall Ring in combination with isotopically pure, highly-polarized internal targets of polarized hydrogen and vector-

  18. Target correlation effects on neutron-nucleus total, absorption, and abrasion cross sections

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.

    1991-01-01

    Second order optical model solutions to the elastic scattering amplitude were used to evaluate total, absorption, and abrasion cross sections for neutron nucleus scattering. Improved agreement with experimental data for total and absorption cross sections is found when compared with first order (coherent approximation) solutions, especially below several hundred MeV. At higher energies, the first and second order solutions are similar. There are also large differences in abrasion cross section calculations; these differences indicate a crucial role for cluster knockout in the abrasion step.

  19. High Resolution Laser Scanning Techniques for Rock Abrasion and Texture Analyses on Mars and Earth

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Razdan, A.; Greeley, R.; Laity, J. E.

    2004-01-01

    Aeolian abrasion is operative in many arid locations on Earth and is probably the dominant rock erosion process in the current Martian environment. Therefore, understanding the controlling parameters and rates of aeolian abrasion provides 1) insight into the stability of rocks on planetary surfaces and the environments under which the rocks abrade, and 2) a link between ventifact (a rock abraded by windblown particles) morphology and: a) abrasion conditions, b) possible ancient environments under which the rocks were abraded, and c) rock properties. promising and we plan further investigations in the wind tunnel and field. Our intent here is to discuss the basic technique, initial results, and upcoming plans.

  20. Three-Body Abrasion Testing Using Lunar Dust Simulants to Evaluate Surface System Materials

    NASA Technical Reports Server (NTRS)

    Kobrick, Ryan L.; Budinski, Kenneth G.; Street, Kenneth W., Jr.; Klaus, David M.

    2010-01-01

    Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement techniques for quantifying controlled volumetric wear. Subsequent efforts described in the paper involved three-body abrasion testing designed to be more representative of actual lunar interactions. For these tests, a new tribotester was developed to expose samples to a variety of industrial abrasives and lunar simulants. The work discussed in this paper describes the three-body hardware setup consisting of a rotating rubber wheel that applies a load on a specimen as a loose abrasive is fed into the system. The test methodology is based on ASTM International (ASTM) B611, except it does not mix water with the abrasive. All tests were run under identical conditions. Abraded material specimens included poly(methyl methacrylate) (PMMA), hardened 1045 steel, 6061-T6 aluminum (Al) and 1018 steel. Abrasives included lunar mare simulant JSC- 1A-F (nominal size distribution), sieved JSC-1A-F (<25 m particle diameter), lunar highland simulant NU-LHT-2M, alumina (average diameter of 50 m used per ASTM G76), and silica (50/70 mesh used per ASTM G65). The measured mass loss from each specimen was converted using standard densities to determine total wear volume in cm3. Abrasion was dominated by the alumina and the simulants were only similar to the silica (i.e., sand) on the softer materials of aluminum and PMMA. The nominal JSC- 1A-F consistently showed more abrasion wear than the sieved version of the simulant. The lunar dust displayed abrasivity to all of the test materials, which are likely to be used in lunar landing equipment. Based on this test experience and pilot results obtained, recommendations are made for systematic abrasion testing of candidate materials intended for use in lunar exploration systems and in other environments with similar dust challenges.

  1. Concussive brain injury from explosive blast

    PubMed Central

    de Lanerolle, Nihal C; Hamid, Hamada; Kulas, Joseph; Pan, Jullie W; Czlapinski, Rebecca; Rinaldi, Anthony; Ling, Geoffrey; Bandak, Faris A; Hetherington, Hoby P

    2014-01-01

    Objective Explosive blast mild traumatic brain injury (mTBI) is associated with a variety of symptoms including memory impairment and posttraumatic stress disorder (PTSD). Explosive shock waves can cause hippocampal injury in a large animal model. We recently reported a method for detecting brain injury in soldiers with explosive blast mTBI using magnetic resonance spectroscopic imaging (MRSI). This method is applied in the study of veterans exposed to blast. Methods The hippocampus of 25 veterans with explosive blast mTBI, 20 controls, and 12 subjects with PTSD but without exposure to explosive blast were studied using MRSI at 7 Tesla. Psychiatric and cognitive assessments were administered to characterize the neuropsychiatric deficits and compare with findings from MRSI. Results Significant reductions in the ratio of N-acetyl aspartate to choline (NAA/Ch) and N-acetyl aspartate to creatine (NAA/Cr) (P < 0.05) were found in the anterior portions of the hippocampus with explosive blast mTBI in comparison to control subjects and were more pronounced in the right hippocampus, which was 15% smaller in volume (P < 0.05). Decreased NAA/Ch and NAA/Cr were not influenced by comorbidities – PTSD, depression, or anxiety. Subjects with PTSD without blast had lesser injury, which tended to be in the posterior hippocampus. Explosive blast mTBI subjects had a reduction in visual memory compared to PTSD without blast. Interpretation The region of the hippocampus injured differentiates explosive blast mTBI from PTSD. MRSI is quite sensitive in detecting and localizing regions of neuronal injury from explosive blast associated with memory impairment. PMID:25493283

  2. Bayesian detection of acoustic muzzle blasts

    Microsoft Academic Search

    Kenneth D. Morton Jr.; Leslie Collins

    2009-01-01

    Acoustic detection of gunshots has many security and military applications. Most gunfire produces both an acoustic muzzle-blast signal as well as a high-frequency shockwave. However some guns do not propel bullets with the speed required to cause shockwaves, and the use of a silencer can significantly reduce the energy of muzzle blasts; thus, although most existing commercial and military gunshot

  3. Gasification of phosphorus in the blast furnace

    Microsoft Academic Search

    L. A. Polulyakh; A. L. Petelin; V. Ya. Dashevskii; A. Ya. Travyanov; Yu. S. Yusfin

    2009-01-01

    The behavior of phosphorus in blast-furnace smelting requires further study, in order to determine its distribution among the products. It is conventional to assume that practically all the phosphorus supplied to the blast furnace with the batch enters the hot metal [1]. However, in recent balance calculations, estimates have been obtained for the ratio of the quantity of phosphorus supplied

  4. Zinc recovery from blast furnace flue dust

    Microsoft Academic Search

    B. Asadi Zeydabadi; D. Mowla; M. H. Shariat; J. Fathi Kalajahi

    1997-01-01

    Blast furnace flue dusts are a mixture of oxides expelled from the top of the blast furnace, whose major components are iron oxides. They also contain zinc, silicon, magnesium and other minor element oxides in lesser amounts. The direct recycling of flue dust is not usually possible since it contains some undesirable elements (zinc and alkaline metals) that can cause

  5. Existing and prospective blast-furnace conditions

    SciTech Connect

    I.G. Tovarovskii; V.I. Bol'shakov; V.P. Lyalyuk; A.E. Merkulov; D. V. Pinchuk [Ukrainian Academy of Sciences, Dnepropetrovsk (Ukraine). Institute of Ferrous Metallurgy

    2009-07-15

    Blast-furnace conditions are investigated by means of a multizone model. The expected performance of prospective technologies is assessed, as well as the trends in blast-furnace processes. The model permits the identification of means of overcoming practical difficulties.

  6. Highly concentrated foam formulation for blast mitigation

    DOEpatents

    Tucker, Mark D. (Albuquerque, NM); Gao, Huizhen (Albuquerque, NM)

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  7. Color changing photonic crystals detect blast exposure

    PubMed Central

    Cullen, D. Kacy; Xu, Yongan; Reneer, Dexter V.; Browne, Kevin D.; Geddes, James W.; Yang, Shu; Smith, Douglas H.

    2010-01-01

    Blast-induced traumatic brain injury (bTBI) is the “signature wound” of the current wars in Iraq and Afghanistan. However, with no objective information of relative blast exposure, warfighters with bTBI may not receive appropriate medical care and are at risk of being returned to the battlefield. Accordingly, we have created a colorimetric blast injury dosimeter (BID) that exploits material failure of photonic crystals to detect blast exposure. Appearing like a colored sticker, the BID is fabricated in photosensitive polymers via multi-beam interference lithography. Although very stable in the presence of heat, cold or physical impact, sculpted micro- and nano-structures of the BID are physically altered in a precise manner by blast exposure, resulting in color changes that correspond with blast intensity. This approach offers a lightweight, power-free sensor that can be readily interpreted by the naked eye. Importantly, with future refinement this technology may be deployed to identify soldiers exposed to blast at levels suggested to be supra-threshold for non-impact blast-induced mild TBI. PMID:21040795

  8. PROTECTIVE DESIGNS FOR BLAST AND IMPACT THREATS

    Microsoft Academic Search

    J. E. Crawford

    This paper describes methods for designing and implementing protective technologies for improving the blast and impact resistance of buildings. A protection plan for buildings may include designing blast-resistant columns, walls, and windows; other elements of security may also play a major part, including physical security measures such as: anti-ram barriers and fencing to demarcate a protective perimeter; features such as

  9. Blast wave reflection from lightly destructible wall

    Microsoft Academic Search

    V. V. Golub; T. V. Bazhenova; O. A. Mirova; Y. L. Sharov; V. V. Volodin

    The paper presents the results of experimental study of the action of blast waves on the obstacle made of different materials.\\u000a The pressure in the front of reflected blast wave is compared in the cases of its interaction with a rigid metal wall and\\u000a the destructible wall made of weakly cemented sand.

  10. Building BLAST for Coprocessor Accelerators Using Macah

    Microsoft Academic Search

    Ben Weintraub

    Abstract The problem of detecting similarities between different genetic sequences is fun- damental to many,research pursuits in biology and genetics. BLAST (Basic Local Alignment and Search Tool) is the most commonly,used tool for identi- fying and assessing the significance of such similarities. With the quantity of available genetic sequence data rapidly increasing, improving the performance of the BLAST algorithm is

  11. Paint removal using wheat starch blast media

    Microsoft Academic Search

    Terry Foster; John Oestreich

    1993-01-01

    A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of

  12. What a gas: Blasting under pressure

    SciTech Connect

    Wallace, J.

    1996-12-31

    This project consisted of blasting for expansion of a major interstate natural gas transmission pipeline pump station. The pump station handled 400--500 million cubic feet (11--14 million cubic meters) of gas per day. Site work blasting for the new 4,000 horsepower 200 ton (3,000 kW 180 tonnes) compressor engine and pump took place to within 24 feet (7.5 meters) of the existing operating unit. All trenching operations were within 20 feet (6 meters) of existing apparatus and lines, some of which were 30 inches (0,75 meter) diameter and carried 700 psi (4,800 kPa) pressure. This was the first time the owner had allowed blasting in such close proximity to large pressurized lines while the compressor station pump-engine continued operating. Two off-site incidents occurred between the time the blasting option was accepted and the start of operations that heightened valid owner and regulatory agency concerns. The first was a line break and resultant 10 acre (4 hectare) fire approximately 400 mile s(65 km) from the project site. The second was the bombing of the federal building in Oklahoma City. As a result, the owner and the local Fire Marshal`s office required an extensive, revised blasting safety and transportation plan. Blasting began furthest from the highest hazard. Vibration data and blast results were continually analyzed as blasting progressed, with necessary changes made prior to moving into the next zone.

  13. The effect on cast post dimensions of casting investment and airborne particle abrasion.

    PubMed

    Hashem, Danya; German, Matthew J; Wassell, Robert W

    2011-09-01

    Cast posts can sometimes prove difficult to seat fully during fitting. This study compared two different liquid/water dilutions for phosphate bonded investment and the effect of controlled airborne particle abrasion on resulting post diameter. After measuring polymeric post patterns (n = 18), 3 groups were invested using concentrated solution and 3 groups using dilute solution. After casting they were weighed and remeasured then exposed to airborne particle abrasion. Both solutions produced oversized cast posts. Mean diameter reduction during airborne particle abrasion was 8 microm/10s taking an average of 41s to reach precast size. Where a post pattern fits tightly, airborne particle abrasion for 70s should reduce the casting sufficiently to accommodate the cement lute. PMID:22645794

  14. Experimental Testing of an Electrical Submersible Pump Undergoing Abrasive Slurry Erosion 

    E-print Network

    Saleh, Ramy Moaness M

    2013-04-01

    The Electrical Submersible Pump (ESP) manufactured by Baker Hughes, model no. WJE-1000 is designed for wells that are expected to have a high content of abrasive solids. It is a mixed flow, tandem compression type pump. Although the erosion...

  15. Particle Abrasion Within the Chicxulub Ejecta Blanket: Implications for the Emplacement Process

    NASA Astrophysics Data System (ADS)

    Schönian, F.; Stöffler, D.; Kenkmann, T.

    2008-03-01

    Roundness and sphericity of 1575 clasts from 14 localities of Chicxulub ejecta blanket were measured. Increasing particle abrasion with crater distance can be related to a viscous and erosive secondary flow with increasing strain localization.

  16. Effect of canopy leaf distribution on sand transport and abrasion energy

    NASA Astrophysics Data System (ADS)

    Hagen, L. J.; Casada, M. E.

    2013-09-01

    During times when crop canopies are short or sparse, wind erosion can uncover plant roots, deplete the soil resource, and damage plants by abrasion and desiccation. Few studies have considered the effects of position and number of leaves on sand transport and the distribution of the sand abrasion energy. The objectives of this study were to determine the effects of number and distribution of leaves on threshold velocities, sand transport rates, and relative abrasion energy among simulated dicotyledonous plant canopies. Six canopies were tested in a wind tunnel with two levels of leaf area index (LAI), two different maximum leaf heights, and either two or four leaves per plant with maximum freestream wind speeds from 12 to 17 m s-1. The leaf heights were selected to position the lowest leaves to be either intercepting saltating sand or largely above the saltation layer. The wind tunnel was a 1.52 W × 1.82 H × 15.3 L m push-type recirculating tunnel with the floor covered with a layer of sieved sand. Sand discharge and relative abrasion energy were measured during 3-min duration test runs. For canopies with two leaves, the experimental sand transport capacity was reduced most when the leaves were highest above the surface even though they were intercepting saltation when in their lowest positions. As expected, canopy LAI was directly related to threshold velocity and inversely related to sand transport capacity. Total abrasion energy impacting the target soil channel containers located vertically in the canopy increased with wind speeds above the threshold. Within canopies, high wind speeds increased height of maximum abrasion but often still caused less total abrasion per unit sand discharge than over a bare, sandy surface. When leaves were located nearest the surface, they modified the vertical abrasion profiles by deflecting a portion of the sand impact energy upward in the wind stream. Overall, the canopies modified both the profiles and normalized abrasion energy of the sand discharge when compared with a bare, sandy surface. Hence, it may be important to place test plants within a canopy of similar plants—to allow development of a fully developed velocity profile in the canopy by using a minimum upwind fetch of about 70 canopy heights in a wind tunnel—when conducting plant abrasion tests using sand to achieve results representative of plants in the interior of a field. In contrast, abrasion on inter-row flat soil containers was independent of wind speeds, but was higher without a canopy compared with measurements in the canopy for a given sand discharge.

  17. Layered sacrificial claddings under blast loading Part II — experimental studies

    Microsoft Academic Search

    S. Guruprasad; Abhijit Mukherjee

    2000-01-01

    This paper discusses the performance of sacrificial layer under blast loading. A number of blast experiments have been carried out on sacrificial layered claddings. The blast overpressures were recorded by two crystal-type blast pressure gauges. The deformations of the layers of the claddings were also recorded. The layers collapsed successively in the same manner as predicted in the analytical studies.

  18. Characterization of novel blast resistant genes for US rice breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blast resistance genes, such as Pi-ta, conveying resistance up to 8 common US races of the blast pathogen (Magnaporthe oryzae), have been used for 20 years in the US rice (Oryza sativa) industry. However, Pi-ta is susceptible to two known US races of blast. Race IE-1K has caused blast outbreaks in A...

  19. Predicting the effectiveness of blast wall barriers using neural networks

    Microsoft Academic Search

    Alex M. Remennikov; Timothy A. Rose

    2007-01-01

    Blast damage assessment of buildings and structural elements requires an accurate prediction of the blast loads in terms of the peak pressures and impulses. Blast loadings on structures have typically been evaluated using empirical relationships. These relationships assume that there are no obstacles between the explosive device and the target. If a blast barrier is used to protect personnel or

  20. Behavior of Silicone Sealants in Bomb Blast Mitigating Window Designs

    Microsoft Academic Search

    Kenneth Yarosh; Gerald Braeuer; Sigurd Sitte

    2002-01-01

    The threat of terrorist attack impacts our lives every day. Because this threat is very real, we have seen the use of bomb blast mitigating window designs grow significantly in recent years. Effective bomb blast mitigating window designs allow the window system to withstand a moderate bomb blast without causing significant injury to building occupants from the blast itself or

  1. Aspects of blast resistant masonry design

    SciTech Connect

    Volkman, D.E.

    1989-01-01

    Blast resistant design should be examined for building code incorporation, due to the potential of explosions occurring in an industrial society. Specifically, public and commercial structures of concrete masonry construction need additional building code criteria, since these buildings have high density populations to protect. Presently, blast resistant design is accomplished by using government published manuals, but these do not address industry standard construction. A design air blast load of 4.54 kg (10 lbs) of TNT, located 0.91 m (3 ft) above ground surface and 30.48 m (100 ft) from a structure should be considered standard criteria. This loading would be sufficient to protect against blast, resist progressive failure, and yet not be an economic impediment. Design details and adequate inspection must be observed to ensure blast resistant integrity. 10 refs., 3 figs., 1 tab.

  2. Abrasive wear property of laser melting\\/deposited Ti 2Ni\\/TiNi intermetallic alloy

    Microsoft Academic Search

    Fei GAO; Hua-Ming WANG

    2007-01-01

    A wear resistant intermetallic alloy consisting of TiNi primary dendrites and Ti2Ni matrix was fabricated by the laser melting deposition manufacturing process. Wear resistance of Ti2Ni\\/TiNi alloy was evaluated on an abrasive wear tester at room temperature under the different loads. The results show that the intermetallic alloy suffers more abrasive wear attack under low wear test load of 7,

  3. Correlation between the surface quality and the abrasive grains wear in optical glass lapping

    Microsoft Academic Search

    N. Belkhir; D. Bouzid; V. Herold

    2007-01-01

    The subject of this study is to determine the relation between the optical glass surface quality and the wear of abrasive grains used in finishing process. The glass surface quality was characterized by the roughness (rms,CLA and peak to valley). Alumina abrasive grains (Al2O3) are used with average sizes (80, 40, 20, 7?m) respectively. After 2min lapping for each fraction

  4. Non-steroidal anti-inflammatory drugs decrease the quality of pleurodesis after mechanical pleural abrasion

    Microsoft Academic Search

    D. Lardinois; P. Vogt; L. Yang; I. Hegyi; M. Baslam; W. Weder

    2004-01-01

    Objective: Non-steroidal anti-inflammatory drugs (NSAIDs) are often applied for pain management after thoracic surgery. Since these drugs diminish collagen deposition through inhibition of the prostaglandin synthesis, we investigated their effects on adhesion formation after endoscopic mechanical pleural abrasion, which is often applied in the therapy of pneumothorax. Methods: Mechanical pleural abrasion was performed unilaterally by the use of video-assisted thoracoscopic

  5. A Material Removal Model for CMP Based on the Contact Mechanics of Pad, Abrasives, and Wafer

    Microsoft Academic Search

    Dinc?er Bozkaya; Sinan Mu?ftu?

    2009-01-01

    Applied pressure in chemical mechanical polishing CMP is shared by the two-body pad-wafer and the three-body pad-abrasive- wafer contacts. The fraction of applied pressure transferred through the particle contacts is a significant factor as most of the material removal is due to abrasive particles trapped in the pad-wafer interface. In this work, the contact of a rough, deformable pad and

  6. Finishing effect of abrasive flow machining on micro slit fabricated by wire-EDM

    Microsoft Academic Search

    Hsinn-Jyh Tzeng; Biing-Hwa Yan; Rong-Tzong Hsu; Han-Ming Chow

    2007-01-01

    This experimental research use the method of abrasive flow machining (AFM) to evaluate the characteristics of various levels\\u000a of roughness and finishing of the complex shaped micro slits fabricated by wire electrical discharge machining (Wire-EDM).\\u000a An investigative methodology based on the Taguchi experimental method for the micro slits of biomedicine was developed to\\u000a determine the parameters of AFM, including abrasive

  7. Prediction of surface roughness in abrasive waterjet machining of particle reinforced MMCs using genetic expression programming

    Microsoft Academic Search

    Metin Kök; Erdogan Kanca; Ömer Eyercio?lu

    2011-01-01

    Machining of particle-reinforced metal matrix composites has been considerably difficult due to the extremely abrasive nature\\u000a of the reinforcements that causes rapid tool wear and high machining cost. Abrasive water jet (AWJ) machining has proven to\\u000a be a viable technique to machine such materials compared to conventional machining processes. The present study is focused\\u000a on the surface roughness of AWJ

  8. Resistance of a binderless cemented carbide to abrasion and particle erosion

    Microsoft Academic Search

    H. Engqvist; N. Axén; S. Hogmark

    1998-01-01

    A binderless cemented carbide has been evaluated in abrasion and erosion tests. The binderless carbide was compared with:\\u000a SiC, Al2O3 and two conventional cemented carbides with 6% Co and different WC grain sizes (1 and 7 ?m). In the abrasion tests, the materials\\u000a were ground with silica, silicon carbide and diamond particles in the size range of 5–15 ?m. The

  9. On the Propagation and Interaction of Spherical Blast Waves

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Freeman, Robert

    2007-01-01

    The characteristics and the scaling laws of isolated spherical blast waves have been briefly reviewed. Both self-similar solutions and numerical solutions of isolated blast waves are discussed. Blast profiles in the near-field (strong shock region) and the far-field (weak shock region) are examined. Particular attention is directed at the blast overpressure and shock propagating speed. Consideration is also given to the interaction of spherical blast waves. Test data for the propagation and interaction of spherical blast waves emanating from explosives placed in the vicinity of a solid propellant stack are presented. These data are discussed with regard to the scaling laws concerning the decay of blast overpressure.

  10. Two-Phase Abrasion in Eolian Transport of Gypsum Sand, White Sands NM

    NASA Astrophysics Data System (ADS)

    Shaw, S.; Jerolmack, D. J.; Miller, K. L.

    2014-12-01

    Downstream rounding of grains is consistently observed in natural sediment transport settings. A recent theory put forth by Domokos et al. (2014) attributes particle rounding and size reduction to a geometric curvature-driven abrasion process. This process occurs in two phases, in which irregularly shaped or angular particles round to convex shapes with negligible change in axis dimension, then slowly reduce in particle diameter. Miller et al (in review) establish the existence of two-phase abrasion in the natural setting of a fluvial gravel stream. This study examines field samples from White Sands, NM to investigate the presence of two-phase abrasion in a different, non-idealized natural environment - a high-energy, eolian gypsum dunefield. Analysis of grain shapes from White Sands confirms the two-phase abrasion process, dependent upon mode of sediment transport. We find that large sand grains carried in saltation bed load transport exhibit shape change indicative of two-phase abrasion, while smaller particles carried in suspension do not. We observe rapid shape change in bed load particles approaching a convex shape, followed by slower reduction in grain axis dimensions. Confirmation of this process in a natural, non-idealized setting establishes two-phase abrasion as a general application for bed load transport.

  11. Age-related mandible abrasion in the groundhopper Tetrix tenuicornis (Tetrigidae, Orthoptera).

    PubMed

    Ku?avová, Kate?ina; Hajduková, Lenka; Ko?árek, Petr

    2014-05-01

    A study was conducted to determine whether the mandibles of the detrito-/bryophagous groundhopper Tetrix tenuicornis are subject to mechanical wear as a result of feeding, as is the case for grasshoppers that feed on silica-rich grasses. Abrasion was evaluated by measuring the length and width of the 3rd incisor and length of the 4th incisor in adults of different ages collected under natural conditions during one season. Although T. tenuicornis and other groundhoppers avoid feeding on grasses, we found that mandible abrasion increased with T. tenuicornis age. Age-related abrasion of the incisors of left and right mandibles was statistically significant in both sexes but the degree of abrasion was greater for females than males, apparently reflecting differences in the frequency and magnitude of feeding. Degree of abrasion also differed between right and left mandibles, probably because of differences in how each mandible is used during food processing. Abrasion of cuticular mandible structures may reduce the effectiveness of food processing late in the season. PMID:24583696

  12. Relationships Between Abrasion Index and Shape Properties of Progressively Abraded Dolerite Railway Ballasts

    NASA Astrophysics Data System (ADS)

    Okonta, F. N.

    2014-07-01

    Sub-angular-shaped aggregates are used as rail foundation ballasts and must remain sub-angular during their service life time to maintain particle-particle interlocking, in order to ensure the stability of the rail line and prevent accidents by derailment. Here, the screening of dolerite quarry aggregates for use as railway foundation ballasts was investigated by employing simple digital image and chart methods. The average particle size ( d 50), flakiness index (FI), Los Angeles abrasion index (LAAI), sphericity (SPH) and roundness (RND) were determined for two batches of dolerite ballasts from the Rooikraal quarry in Johannesburg and Ngagane quarry in Newcastle. Thirty samples from each of the two batches of ballast were analysed. The ballasts were progressively abraded using a Los Angeles abrasion device and were analysed after each cycle of abrasion. A decrease in d 50 and an increase in FI with increased number of abrasion cycles were observed for both batches of dolerite ballast. The difference in the chart and digital image values of RND and SPH were marginal before abrasion; however, these differences increased with each abrasion cycle. The LAAI, d 50, mean RND and mean SPH correlated significantly and were found to have high regression coefficients. Thus, statistical models are proposed for the non-destructive routine screening of in-place ballasts in order to track marginal changes in aggregate shapes, facilitate ballast replacement programmes and avoid rail line instability.

  13. Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD

    SciTech Connect

    Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

    2010-03-15

    This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

  14. Minimization of carryover for high-throughput liquid chromatography with tandem mass spectrometry analysis of 14 mycotoxins in corn grits.

    PubMed

    Tamura, Masayoshi; Matsumoto, Keiko; Watanabe, Jun; Iida, Junko; Nagatomi, Yasushi; Mochizuki, Naoki

    2014-07-01

    A method for the simultaneous analysis of 14 mycotoxins with the minimization of carryover was developed. Our verification experiments suggested that the carryover occurred due to the chelation of fumonisins with the metal. To wash the fumonisins from the metal, the inner surface of the injection needle was rinsed with 10 mM trisodium citrate and 1% formic acid in water/methanol/acetonitrile/isopropanol after each injection, and the analysis was performed on a metal-free Mastro C18 column. This approach remarkably minimized the carryover of fumonisins. Fourteen mycotoxins in samples were extracted with 2% acetic acid in water/acetonitrile and a quick, easy, cheap, effective, rugged, and safe extraction kit, purified on a MultiSep 229 Ochra, and then quantified by liquid chromatography with tandem mass spectrometry. Determinations performed using this method produced a linearity greater than 0.99 and recoveries ranging from 72.6 to 117.4%, with good intraday precision from 4.0 to 12.4%, and interday precision from 6.5 to 17.0%. The limits of detection ranged from 0.01 to 0.71 ?g/kg, demonstrating that a highly sensitive method for the simultaneous analysis of mycotoxins over a wide range of concentrations was achieved with minimal carryover. When 12 samples of commercially available corn grits were analyzed with this method, deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, and zearalenone were present most frequently. PMID:24723378

  15. Chronic Traumatic Encephalopathy in Blast-Exposed Military Veterans and a Blast Neurotrauma Mouse Model

    PubMed Central

    Goldstein, Lee E.; Fisher, Andrew M.; Tagge, Chad A.; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A.; Upreti, Chirag; Kracht, Jonathan M.; Ericsson, Maria; Wojnarowicz, Mark W.; Goletiani, Cezar J.; Maglakelidze, Giorgi M.; Casey, Noel; Moncaster, Juliet A.; Minaeva, Olga; Moir, Robert D.; Nowinski, Christopher J.; Stern, Robert A.; Cantu, Robert C.; Geiling, James; Blusztajn, Jan K.; Wolozin, Benjamin L.; Ikezu, Tsuneya; Stein, Thor D.; Budson, Andrew E.; Kowall, Neil W.; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F.; Moss, William C.; Cleveland, Robin O.; Tanzi, Rudolph E.; Stanton, Patric K.; McKee, Ann C.

    2013-01-01

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein–linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory. PMID:22593173

  16. Experimental Study on Abrasive Waterjet Polishing of Hydraulic Turbine Blades

    NASA Astrophysics Data System (ADS)

    Khakpour, H.; Birglenl, L.; Tahan, A.; Paquet, F.

    2014-03-01

    In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated.

  17. Installation of Standalone BLAST on Windows PC A suite of programs for performing BLAST sequence alignment locally against custom datasets

    E-print Network

    Levin, Judith G.

    and their intended platforms. BLAST+ Packages Intended operating system ncbi-blast-#.#.#+-3.i686.rpm 32-bit linux rpm package ncbi-blast-#.#.#+-3.x86_64.rpm 64-bit linux rpm package ncbi-blast-#.#.#+-ia32-linux.tar.gz 32-bit Linux platform ncbi-blast-#.#.#+-ia32-win32.tar.gz 32-bit Windows, equivalent to win32.exe ncbi

  18. ScalaBLAST 2.0: rapid and robust BLAST calculations on multiprocessor systems

    PubMed Central

    Oehmen, Christopher S.; Baxter, Douglas J.

    2013-01-01

    Motivation: BLAST remains one of the most widely used tools in computational biology. The rate at which new sequence data is available continues to grow exponentially, driving the emergence of new fields of biological research. At the same time, multicore systems and conventional clusters are more accessible. ScalaBLAST has been designed to run on conventional multiprocessor systems with an eye to extreme parallelism, enabling parallel BLAST calculations using >16 000 processing cores with a portable, robust, fault-resilient design that introduces little to no overhead with respect to serial BLAST. Availability: ScalaBLAST 2.0 source code can be freely downloaded from http://omics.pnl.gov/software/ScalaBLAST.php. Contact: christopher.oehmen@pnl.gov PMID:23361326

  19. Acceleration of Ungapped Extension in Mercury BLAST

    PubMed Central

    Buhler, Jeremy; Chamberlain, Roger D.

    2007-01-01

    The amount of biosequence data being produced each year is growing exponentially. Extracting useful information from this massive amount of data efficiently is becoming an increasingly difficult task. There are many available software tools that molecular biologists use for comparing genomic data. This paper focuses on accelerating the most widely used such tool, BLAST. Mercury BLAST takes a streaming approach to the BLAST computation by off loading the performance-critical sections to specialized hardware. This hardware is then used in combination with the processor of the host system to deliver BLAST results in a fraction of the time of the general-purpose processor alone. This paper presents the design of the ungapped extension stage of Mercury BLAST. The architecture of the ungapped extension stage is described along with the context of this stage within the Mercury BLAST system. The design is compact and runs at 100 MHz on available FPGAs, making it an effective and powerful component for accelerating biosequence comparisons. The performance of this stage is 25× that of the standard software distribution, yielding close to 50× performance improvement on the complete BLAST application. The sensitivity is essentially equivalent to that of the standard distribution. PMID:20160873

  20. LTC vacuum blasting machine (concrete): Baseline report

    SciTech Connect

    NONE

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC 1073 Vacuum Blasting Machine uses a high-capacity, direct-pressure blasting system which incorporates a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast. It incorporates a vacuum system which removes dust and debris from the surface as it is blasted. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure during maintenance activities was minimal, but due to mechanical difficulties dust monitoring could not be conducted during operation. Noise exposure was significant. Further testing for each of these exposures is recommended because of the outdoor environment where the testing demonstration took place. This may cause the results to be inaccurate. It is feasible that the dust and noise levels will be higher in an enclosed environment. In addition, other safety and health issues found were ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, and arm-hand vibration.

  1. Failure of a novel silicone–polyurethane copolymer (Optim™) to prevent implantable cardioverter-defibrillator lead insulation abrasions

    PubMed Central

    Hauser, Robert G.; Abdelhadi, Raed H.; McGriff, Deepa M.; Kallinen Retel, Linda

    2013-01-01

    Aim The purpose of this study was to determine if Optim™, a unique copolymer of silicone and polyurethane, protects Riata ST Optim and Durata implantable cardioverter-defibrillator (ICD) leads (SJM, St Jude Medical Inc., Sylmar, CA, USA) from abrasions that cause lead failure. Methods and results We searched the US Food and Drug Administration's (FDA's) Manufacturers and User Device Experience (MAUDE) database on 13 April 2012 using the simple search terms ‘Riata ST Optim™ abrasion analysis’ and ‘Durata abrasion analysis’. Lead implant time was estimated by subtracting 3 months from the reported lead age. The MAUDE search returned 15 reports for Riata ST Optim™ and 37 reports for Durata leads, which were submitted by SJM based on its analyses of returned leads for clinical events that occurred between December 2007 and January 2012. Riata ST Optim™ leads had been implanted 29.1 ± 11.7 months. Eight of 15 leads had can abrasions and three abrasions were caused by friction with another device, most likely another lead. Four of these abrasions resulted in high-voltage failures and one death. One failure was caused by an internal insulation defect. Durata leads had been implanted 22.2 ± 10.6 months. Twelve Durata leads had can abrasions, and six leads had abrasions caused by friction with another device. Of these 18 can and other device abrasions, 13 (72%) had electrical abnormalities. Low impedances identified three internal insulation abrasions. Conclusions Riata ST Optim™ and Durata ICD leads have failed due to insulation abrasions. Optim™ did not prevent these abrasions, which developed ?4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications. PMID:22915789

  2. Abrasive Wear Comparison of Cr 3C 2\\/Ni 3Al Composite and Stellite 12 Alloy Cladding

    Microsoft Academic Search

    He-li LUO; Gong Karin; Shang-ping LI; Xu CAO; Xi-e ZHANG; Di FENG; Chang-hai LI

    2007-01-01

    The room-temperature abrasive wear resistance of Cr3C2\\/Ni3Al composite and Stellite 12 alloy cladding was investigated. Three kinds of tests, designed for different load and abrasive' size, were utilized to understand the wear behaviour of these materials. Under all three wear conditions, the abrasion resistance of Cr3C2\\/Ni3Al composite cladding is much higher than Stellite 12 alloy. In addition, the wear-resistant advantage

  3. Dry media blasting with wheat starch

    NASA Astrophysics Data System (ADS)

    Foster, Terry

    1995-04-01

    The brand name TECHNOSTRIP covers several types of installations and facilities. These were developed mainly to meet the requirements of customers in the aeronautic field. The range of products includes: complete self-supporting and semi-automated system for aircraft stripping; large-size blasting booth for semi-automatic stripping; manual blasting booth; and sealed and portable manual stripping head. Wheat starch media was developed for particle blasting stripping and is used in TECHNOSTRIP. This paper reviews its origins and use as well as use of automated facilities, reliability, effects on materials, effects on environment, and utilization examples.

  4. CO{sub 2} pellet blasting studies

    SciTech Connect

    Archibald, K.E.

    1997-01-01

    Initial tests with CO{sub 2} pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO{sub 2} pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO{sub 2} blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report.

  5. Gun blast - Its propagation and determination

    NASA Astrophysics Data System (ADS)

    Schmidt, E. M.; Kahl, G. D.; Shear, D. D.

    1980-06-01

    Muzzle blast overpressure levels are limiting the operation of high performance gun systems. The pressures at crew stations are of particular concern and have not been well defined either experimentally or analytically. The present paper presents measurement and analysis of the blast fields about a range of weapons from small arms through artillery. The effects of near muzzle flow upon the blast wave are discussed and a scaling relationship is developed from experimental data which is extended to various weapons and shown to predict pressure acceptably.

  6. Industrial cooling tower fan blade having abrasion resistant leading edge

    SciTech Connect

    Burdick, L.F.; Mayes, S.E.

    1992-06-23

    This patent describes a glass fiber reinforced, synthetic resin fan blade for large diameter industrial water cooling tower fans, wherein the outer body portion of the blade is constructed of a thermoset resin and has upper and lower surfaces of which a part thereof define an elongated leading which would be subject to abrasion deterioration during use of the blade. This patent describes improvement in an elongated protective outermost sheet member having opposed, longitudinally extending edges and wrapped over at least a part of the longitudinal extent of the leading edge of the blade with one of the longitudinally extending edges of the member overlying the upper surface of the blade outer body portion and the other longitudinally extending edge of the member on the lower surface of the blade outer body portion, means for mechanically attaching the member to the blade outer body portion substantially throughout the length of the member; and means for attaching the member to the blade outer body portion including upper and lower hold down strips of a synthetic resin and disposed in overlying relationship to the longitudinally extending edges of the member on the upper and lower surfaces of the blade outer body portion and over the longitudinally extending areas of the blade outer body portion which are adjacent respective longitudinally extending edges of the member, the member being provided with a series of openings therein, the thermoset resin making up the blade outer body portion extending through respective openings in the member and being joined with an overlying hold down strip.

  7. Economical solutions to blast mitigation on bridges

    E-print Network

    DeRogatis, Austin (Austin Patrick)

    2008-01-01

    Mitigating the energy created from a blast has been a topic of utmost importance in the terrorism-feared world of today. Main targets of concern are passageways that are significant to a specific area, such as bridges. ...

  8. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (b) Loading tubes and casings of dissimilar metals shall not be used because of possible electric transient currents from galvanic action of the metals and water. (c) Only water-resistant blasting caps and detonating cords shall...

  9. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (b) Loading tubes and casings of dissimilar metals shall not be used because of possible electric transient currents from galvanic action of the metals and water. (c) Only water-resistant blasting caps and detonating cords shall...

  10. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (b) Loading tubes and casings of dissimilar metals shall not be used because of possible electric transient currents from galvanic action of the metals and water. (c) Only water-resistant blasting caps and detonating cords shall...

  11. Material Systems for Blast-Energy Dissipation

    SciTech Connect

    James Schondel; Henry S. Chu

    2010-10-01

    Lightweight panels have been designed to protect buildings and vehicles from blast pressures by activating energy dissipation mechanisms under the influence of blast loading. Panels were fabricated which featured a variety of granular materials and hydraulic dissipative deformation mechanisms and the test articles were subjected to full-scale blast loading. The force time-histories transmitted by each technology were measured by a novel method that utilized inexpensive custom-designed force sensors. The array of tests revealed that granular materials can effectively dissipate blast energy if they are employed in a way that they easily crush and rearrange. Similarly, hydraulic dissipation can effectively dissipate energy if the panel features a high fraction of porosity and the panel encasement features low compressive stiffness.

  12. Nucleon and Deuteron Form Factors from BLAST

    SciTech Connect

    Hasell, D. K. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2009-12-17

    The BLAST experiment was designed to study in a systematic manner the spin-dependent, electromagnetic interaction on hydrogen and deuterium. Measuring only asymmetries in electron scattering with respect to the beam helicity, target spin, or both; the BLAST experiment was able to extract information on nucleon and deuteron form factors independent of beam intensity or target density. By further forming 'super-ratios' of asymmetries, measurements were possible independent of beam and target polarization thus reducing uncertainties due to these quantities as well. Some of the form factor results from BLAST will be briefly presented here. Also, in response to observed discrepancies between polarization measurements and those obtained using traditional Rosenbluth separation techniques a proposed experiment, OLYMPUS, which will use the BLAST detector to measure the two photon contribution to elastic electron scattering will also be presented.

  13. Release of carbon nanotubes from an epoxy-based nanocomposite during an abrasion process.

    PubMed

    Schlagenhauf, Lukas; Chu, Bryan T T; Buha, Jelena; Nüesch, Frank; Wang, Jing

    2012-07-01

    The abrasion behavior of an epoxy/carbon nanotube (CNT) nanocomposite was investigated. An experimental setup has been established to perform abrasion, particle measurement, and collection all in one. The abraded particles were characterized by particle size distribution and by electron microscopy. The abrasion process was carried out with a Taber Abraser, and the released particles were collected by a tube for further investigation. The particle size distributions were measured with a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS) and revealed four size modes for all measured samples. The mode corresponding to the smallest particle sizes of 300-400 nm was measured with the SMPS and showed a trend of increasing size with increasing nanofiller content. The three measured modes with particle sizes from 0.6 to 2.5 ?m, measured with the APS, were similar for all samples. The measured particle concentrations were between 8000 and 20,000 particles/cm(3) for measurements with the SMPS and between 1000 and 3000 particles/cm(3) for measurements with the APS. Imaging by transmission electron microscopy (TEM) revealed that free-standing individual CNTs and agglomerates were emitted during abrasion. PMID:22662874

  14. Abrasion model of downstream changes in grain shape and size along the Williams River, Australia

    NASA Astrophysics Data System (ADS)

    Szabó, Tímea; Fityus, Stephen; Domokos, Gábor

    2013-12-01

    pebble abrasion during bed load transport is of fundamental importance in fluvial geomorphology, as it may help to understand downstream fining patterns along gravel bed rivers. Here we review a recently published analytical abrasion model called box equations, which can simultaneously track the shape and size evolution of large pebble populations as the cumulative effect of binary collisions between particles. The model predicts that pebble shapes move away from the sphere and develop sharp edges due to collisional abrasion by sand. We present a field study on the downstream evolution of basalt particle shape and size along the Williams River in the Hunter Valley, Australia. Pebbles get flatter and thinner, and several aquafacts (i.e., abraded pebbles with sharp edges) emerge in the downstream reaches, both suggesting the importance of abrasion by sand. Applying box equations with a few fitted parameters, we present a numerical simulation which reproduces both the shape and size evolution of pebbles along the Williams River. The simulation allows tracking of the shape and size evolution of individual particles as well, revealing an interesting phenomenon that particle size controls shape evolution. Box equations, in combination with existing transport concepts, provide a framework for future shape and size evolution studies in sedimentary environments. In particular, they may help to assess the relative importance of size selective transport versus abrasion in causing downstream fining in gravel bed rivers.

  15. Comparative Evaluation of Gingival Depigmentation using Tetrafluoroethane Cryosurgery and Gingival Abrasion Technique: Two Years Follow Up

    PubMed Central

    Kumar, Santhosh; Bhat, G. Subraya; Bhat, K. Mahalinga

    2013-01-01

    Objective: A comparative evaluation of the gingival depigmentation by using Tetrafluoroethane cryosurgery and the gingival abrasion technique – 2 years of follow up. Material and Methods: Ten systemically healthy patients who were aged 18 to 36 years were selected for the study. Tetrafluoroethane was used for the cryosurgical depigmentation and the gingival abrasion technique used a coarse flame shaped bur. The presence or absence of pigmentation was tabulated, based on the GPI (Gingival Pigmentation Index). For the statistical analysis, Freidman’s test was used. Results: The keratinization was completed within a week after the application of the cryogen and about 10 days after the gingival abrasion technique was done. The statistical analysis which was done after 90th, 180th days and 2 years. The p-value which was obtained (p<.001) showed the superiority of cryosurgery over the gingival abrasion. During the follow up period, no side effects were seen for both the techniques and the improved aesthetics was maintained upto 2 years. Conclusion: The use of cryogen Tetrafluoroethane is easy, practical and inexpensive as compared to gingival abrasion, due to its high rate of recurrence. Hence, it is more acceptable to the patients and the operator. Further studies are needed to assess the long term effectiveness of the cryosurgical method of depigmentation. PMID:23543863

  16. Baryon Loaded Relativistic Blast Waves in Supernovae

    Microsoft Academic Search

    Sayan Chakraborti; Alak Ray

    2011-01-01

    We provide a new analytic blast wave solution which generalizes the Blandford-McKee solution to arbitrary ejecta masses and Lorentz factors. Until recently relativistic supernovae have been discovered only through their association with long-duration gamma-ray bursts (GRBs). The blast waves of such explosions are well described by the Blandford-McKee (in the ultra-relativistic regime) and Sedov-Taylor (in the non-relativistic regime) solutions during

  17. Rice Blast Genomics: K12 Outreach

    NSDL National Science Digital Library

    This outreach component of the Rice Blast Project provides online genomics activities for high-school students. A lab manual is also offered free of charge to teachers of high-school biology in North Carolina, Texas, Kentucky, Arizona, Virginia, and Indiana. The Rice Blast Project is a collaboration of scientists from North Carolina State University, Texas A&M University, University of Kentucky, University of Arizona, Purdue University, Ohio State University, and Virginia Bioinformatics Institute.

  18. Lightweight Energy Absorbers for Blast Containers

    NASA Technical Reports Server (NTRS)

    Balles, Donald L.; Ingram, Thomas M.; Novak, Howard L.; Schricker, Albert F.

    2003-01-01

    Kinetic-energy-absorbing liners made of aluminum foam have been developed to replace solid lead liners in blast containers on the aft skirt of the solid rocket booster of the space shuttle. The blast containers are used to safely trap the debris from small explosions that are initiated at liftoff to sever frangible nuts on hold-down studs that secure the spacecraft to a mobile launch platform until liftoff.

  19. Blast injuries: mechanics and wounding patterns.

    PubMed

    Covey, Dana C; Born, Christopher T

    2010-01-01

    Blast and fragment injuries are the most frequently encountered wounds in modern warfare. Explosive devices have become the preferred weapon of domestic and foreign terrorists because they are relatively inexpensive to manufacture and can cause substantial casualties. Although blast injuries have traditionally been associated with the battlefield, this type of trauma is being seen more commonly today among noncombatants due to increasing worldwide terrorism. PMID:20371000

  20. Space shuttle holddown post blast shield

    NASA Technical Reports Server (NTRS)

    Larracas, F. B.

    1991-01-01

    The original and subsequent designs of the Solid Rocket Booster/Holddown Post blast shield assemblies and their associated hardware are described. It presents the major problems encountered during their early use in the Space Shuttle Program, during the Return-to-Flight Modification Phase, and during their fabrication and validation testing phases. The actions taken to correct the problems are discussed, along with the various concepts now being considered to increase the useful life of the blast shield.

  1. Computer modeling of thoracic response to blast.

    PubMed

    Stuhmiller, J H; Chuong, C J; Phillips, Y Y; Dodd, K T

    1988-01-01

    Primary blast injury affects the gas-containing structures of the body. Damage to the lungs with resultant respiratory insufficiency and arterial embolization of air from alveolar pulmonary venous fistulae is the predominant cause of morbidity and mortality following high-level blast exposure. In an effort to generate a widely applicable damage-risk criterion for thoracic injury from blast we are developing a complex computer finite element model (FEM) of the thorax. Taking an engineering approach, a horizontal cross-section of the thorax is divided into small discrete units (finite elements) of homogeneous structure. The necessary physical properties (density, bulk modulus, etc.) are then determined for each element. Specifying the material constants and geometry of the elements, the computer can load the surface of the structure with some force-time function (blast pressure-time history) and calculate the resultant physical events such as displacement, compression, stress, strain, etc. Computer predictions of pressure wave phenomena in the lung parenchyma are compared with trans-bronchially measured pressures in blast-exposed animals. The model should prove useful in assessing the risk of blast injury in diverse overpressure environments and may give insight into pathophysiologic mechanisms and strategies for protection. PMID:3339675

  2. Highly effective thin-walled hexagonal checker parts for blast furnace hot-blast stoves

    Microsoft Academic Search

    V. V. Primachenko; R. S. Shulyak; V. L. Bulakh; V. V. Martynenko; N. M. Anzheurov; V. D. Troyan; V. Ya. Sakulin; M. Z. Noginskii

    1987-01-01

    Conclusions Experimental lots of thin-walled hexagonal checker parts with a specific heating surface of 48 m2\\/m3 for high-temperature blast furnace hot blast-stoves were produced under production conditions, chamotte ones at Borovichi Refractory Combine, mullite-corundum ones at Zaporozhe and Semiluki Refractory Plants, and dinas at Pervouralsk Dinas Plant.

  3. Inhibitors for organic phosphonic acid system abrasive free polishing of Cu

    NASA Astrophysics Data System (ADS)

    Wei, Zhang; Xinchun, Lu; Yuhong, Liu; Guoshun, Pan; Jianbin, Luo

    2009-01-01

    Organic phosphonic acid system abrasive free slurry for copper polishing is developed in our earlier work. Since material removal rate is too high to be applied as precision polishing slurry for copper, inhibitors are needed. Experiment results also show us that the most commonly used inhibitor benzotriazole is unsuitable for this abrasive free slurry, and then another kind of compound inhibitors for this organic phosphonic acid system abrasive free slurry are developed. The compound inhibitors, consisting of ascorbic acid and ethylene thiourea, can control the material removal rate and also reduce surface roughness. XPS results show that, in the compound inhibitors, ascorbic acid participates in the surface chemical reaction, forms passivating layer on copper surface and helps to control the material removal rate. Corrosion current calculated from polarization curve is consistent with material removal rate. Ethylene thiourea contributes to the reduction of surface roughness, which can be indicated by the peak shape change of S 2p in XPS results.

  4. The rock abrasion record at Gale Crater: Mars Science Laboratory results from Bradbury Landing to Rocknest

    NASA Astrophysics Data System (ADS)

    Bridges, N. T.; Calef, F. J.; Hallet, B.; Herkenhoff, K. E.; Lanza, N. L.; Le Mouélic, S.; Newman, C. E.; Blaney, D. L.; Pablo, M. A.; Kocurek, G. A.; Langevin, Y.; Lewis, K. W.; Mangold, N.; Maurice, S.; Meslin, P.-Y.; Pinet, P.; Renno, N. O.; Rice, M. S.; Richardson, M. E.; Sautter, V.; Sletten, R. S.; Wiens, R. C.; Yingst, R. A.

    2014-06-01

    Ventifacts, rocks abraded by wind-borne particles, are found in Gale Crater, Mars. In the eastward drive from "Bradbury Landing" to "Rocknest," they account for about half of the float and outcrop seen by Curiosity's cameras. Many are faceted and exhibit abrasion textures found at a range of scales, from submillimeter lineations to centimeter-scale facets, scallops, flutes, and grooves. The drive path geometry in the first 100 sols of the mission emphasized the identification of abrasion facets and textures formed by westerly flow. This upwind direction is inconsistent with predictions based on models and the orientation of regional dunes, suggesting that these ventifact features formed from very rare high-speed winds. The absence of active sand and evidence for deflation in the area indicates that most of the ventifacts are fossil features experiencing little abrasion today.

  5. Blast Resistance and Damage Modelling of Fibre Metal Laminates to Blast Loads

    NASA Astrophysics Data System (ADS)

    Mohamed, Galal F. A.; Soutis, Costas; Hodzic, Alma

    2012-06-01

    A robust and efficient computational model has been developed which is capable of modelling the dynamic non-linear behaviour of GLARE panels subjected to blast loadings. Numerical model validation have been performed considering case studies of GLARE panels subjected to a blast-type pressure pulse for which experimental data on the back-face deflection and post-damage observations were available. Excellent agreement of mid-point deflections and evidence of severe yield line deformation were shown and discussed against the performed blast tests. A further parametric study identified GLARE as a potential blast attenuating structure, exhibiting superior blast potential against monolithic aluminium plates. It was concluded that further work needed to be carried out to take into account the influence of geometry (cylindrical structures), pre-pressurisation effects and boundary conditions

  6. NCBI Handout Series | Primer-BLAST | Last Update August 19, 2013 Contact: info@ncbi.nlm.nih.gov NCBI Primer-BLAST

    E-print Network

    Levin, Judith G.

    NCBI Handout Series | Primer-BLAST | Last Update August 19, 2013 Contact: info@ncbi.nlm.nih.gov) http://www.ncbi.nlm.nih.gov/tools/primer-blast/ National Center for Biotechnology Information-based application accessible through the "Specialized BLAST" section of the BLAST homepage (blast.ncbi.nlm.nih.gov

  7. A Critical Review of Non-carious Cervical (Wear) Lesions and the Role of Abfraction, Erosion, and Abrasion

    Microsoft Academic Search

    D. W. Bartlett; P. Shah

    2006-01-01

    The terms ‘abfraction’ and ‘abrasion’ describe the cause of lesions found along the cervical margins of teeth. Erosion, abrasion, and attrition have all been associated with their formation. Early research suggested that the cause of the V-shaped lesion was excessive horizontal toothbrushing. Abfraction is another possible etiology and involves occlusal stress, producing cervical cracks that predispose the surface to erosion

  8. NK cells are necessary for recovery of corneal CD11c+ dendritic cells after epithelial abrasion injury

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mechanisms controlling CD11c(+) MHCII(+) DCs during corneal epithelial wound healing were investigated in a murine model of corneal abrasion. Selective depletion of NKp46(+) CD3- NK cells that normally migrate into the cornea after epithelial abrasion resulted in >85% reduction of the epithelial CD1...

  9. A parametric evaluation of residual stress resulting from abrasive waterjet surface treatments with elastic prestress: Experiments and modeling

    Microsoft Academic Search

    Balaji Sadasivam

    2010-01-01

    Recent advances in Abrasive Waterjet (AWJ) technology have resulted in a new process for surface treatment that is capable of introducing compressive residual stresses and a surface texture that facilitates bonding. The current research focuses on quantifying the influences of Abrasive Waterjet Peening (AWJP) with elastic prestress on the surface and subsurface residual stress distributions and surface texture of three

  10. Structural transformations, strengthening, and wear resistance of titanium nickelide upon abrasive and adhesive wear

    Microsoft Academic Search

    L. G. Korshunov; V. G. Pushin; N. L. Chernenko; V. V. Makarov

    2010-01-01

    Wear resistance and structural transformations upon abrasive and adhesive wear of titanium nickelide Ti49.4Ni50.6 in microcrystalline\\u000a (MC) and submicrocrystalline (SMC) states have been investigated. It has been shown that the abrasive wear resistance of this\\u000a alloy exceeds that of the steel 12Kh18N9 by a factor of about 2, that of the steel 110G13 (Hadfield steel), by a factor of\\u000a 1.3,

  11. A novel low temperature synthesis technique of sol–gel derived nanocrystalline alumina abrasive

    Microsoft Academic Search

    Zicheng Li; Aiju Zhang; Zhihong Li; Yumei Zhu; Liangjun Liu; Huiqiang Xiang

    2011-01-01

    The effect of ball milling process, co-doped seed and two step sintering technique on the properties of sol–gel derived alumina\\u000a abrasive sintered at low temperature was investigated. The results showed that ball milling time with 10 h can be effective\\u000a in enhancing the activity of the precursor and the microstructural uniformity of sintered alumina abrasive. A small amount\\u000a of Al2O3–(NH4)3AlF6 co-doped

  12. A theoretical investigation on the abrasive wear prevention mechanism of ZDDP and ZP tribofilms

    NASA Astrophysics Data System (ADS)

    Onodera, Tasuku; Morita, Yusuke; Suzuki, Ai; Sahnoun, Riadh; Koyama, Michihisa; Tsuboi, Hideyuki; Hatakeyama, Nozomu; Endou, Akira; Takaba, Hiromitsu; Kubo, Momoji; Del Carpio, Carlos A.; Minfray, Clotilde; Martin, Jean-Michel; Miyamoto, Akira

    2008-09-01

    We investigated wear prevention mechanism of tribofilms generated from zinc dialkyldithiophosphate (ZDDP) and zinc dialkylphosphate (ZP) anti-wear additive using molecular dynamics simulations. The friction behavior of two model materials, zinc metathiophosphate and zinc metaphosphate, was studied. The results indicated that zinc metathiophosphate prevents the abrasive wear due to the atomistic digestion of the wear particles in the tribofilm. We also investigated wear prevention mechanism of zinc metaphosphate and found that it has a better wear prevention performance than zinc metathiophosphate as far as abrasive wear is concerned. Our study showed that zinc metaphosphate can achieve good wear prevention and reduce the environmental load since it does not contain sulfur.

  13. 6. Photocopy of a drawing of the lead blast furnace ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopy of a drawing of the lead blast furnace from J.L. Bray, The Principles of Metallurgy, Ginn & Co. New York, 1929. - International Smelting & Refining Company, Tooele Smelter, Blast Furnace Building, State Route 178, Tooele, Tooele County, UT

  14. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...with regard to ground vibration and airblast, the...operations. (b) Monitoring system. Each application...sensitivity of any blast-monitoring equipment and proposed procedures and locations of monitoring. (c) Blasting...

  15. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...with regard to ground vibration and airblast, the...operations. (b) Monitoring system. Each application...sensitivity of any blast-monitoring equipment and proposed procedures and locations of monitoring. (c) Blasting...

  16. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...with regard to ground vibration and airblast, the...operations. (b) Monitoring system. Each application...sensitivity of any blast-monitoring equipment and proposed procedures and locations of monitoring. (c) Blasting...

  17. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...with regard to ground vibration and airblast, the...operations. (b) Monitoring system. Each application...sensitivity of any blast-monitoring equipment and proposed procedures and locations of monitoring. (c) Blasting...

  18. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...with regard to ground vibration and airblast, the...operations. (b) Monitoring system. Each application...sensitivity of any blast-monitoring equipment and proposed procedures and locations of monitoring. (c) Blasting...

  19. INTERIOR VIEW OF BLAST FURNACE NO. 3 LOOKING EAST, SLAG ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF BLAST FURNACE NO. 3 LOOKING EAST, SLAG RUNNERS & GATES IN FOREGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

  20. DETAIL VIEW OF BLAST FURNACE NO. 3 AREA BELOW BUSTLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF BLAST FURNACE NO. 3 AREA BELOW BUSTLE PIPE, CINDER NOTCH IN CENTER, SLAG RUNNER IN FOREGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

  1. 30 CFR 75.1316 - Preparation before blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...using a blasting multimeter or other instrument specifically designed for such use. (3) The blasting cable or detonator circuitry shall not come in contact with energized electric equipment, including cables. (b) Before loading boreholes with...

  2. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  3. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  4. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  5. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  6. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  7. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  8. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  9. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  10. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  11. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

  12. Use of probabilistic methods in evaluating blast performance of structures

    E-print Network

    Gillis, Andrew Nicholas

    2011-01-01

    The social and political climate of the modern world has lead to increased concern over the ability of engineered structures to resist blast events which may be incurred during terrorist attacks. While blast resistance ...

  13. 70. CONTROL PANEL INSIDE OF THE DOROTHY SIX BLAST FURNACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. CONTROL PANEL INSIDE OF THE DOROTHY SIX BLAST FURNACE STOCKHOUSE LOOKING NORTH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  14. 59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING NORTHEAST. THE LADLE HOUSE IS ON THE RIGHT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  15. 68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST FURNACE. INTERIOR OF CAST HOUSE LOOKING NORTH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  16. 3. VIEW OF DUQUESNE'S RAIL LINES AND BLAST FURNACE PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF DUQUESNE'S RAIL LINES AND BLAST FURNACE PLANT LOOKING NORTH. DOROTHY SIX IS THE CLOSEST FURNACE IN THE PHOTOGRAPH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  17. 58. LOOKING EAST DOROTHY SIX BLAST FURNACE WITH BRICK SHED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. LOOKING EAST DOROTHY SIX BLAST FURNACE WITH BRICK SHED No. 3 IN FOREGROUND ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  18. 55. GENERAL NORTHEASTERN VIEW OF DOROTHY SIX BLAST FURNACE COMPLEX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. GENERAL NORTHEASTERN VIEW OF DOROTHY SIX BLAST FURNACE COMPLEX WITH LADLE HOUSE AND IRON DESULPHERIZATION BUILDING ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  19. 56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST HOUSE IN FOREGROUND AND DUSTCATCHER AT RIGHT OF FURNACE (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  20. Numerical simulation of blast wave interaction with structure columns

    Microsoft Academic Search

    Yanchao Shi; Hong Hao; Zhong-Xian Li

    2007-01-01

    Accurate estimation of blast loads on structures is essential for reliable predictions of structural response and damage.\\u000a Current practice in blast effect analysis and design estimates blast loads primarily based on empirical formulae obtained\\u000a from field blast tests. Due to the limited availability of test data, those empirical formulae are usually applicable to the\\u000a case that the reflection surface of

  1. Integrating Gene Ontology and Blast to predict gene functions

    Microsoft Academic Search

    WANG Cheng-gang; MO Zhi-hong

    2007-01-01

    A GoBlast system was built to predict gene function by integrating Blast search and Gene Ontology (GO) annotations together. The operation system was based on Debian Linux 3.1, with Apache as the web server and Mysql database as the data storage system. FASTA files with GO annotations were taken as the sequence source for blast alignment, which were formatted by

  2. BLAST FURNACE CAST HOUSE EMISSION CONTROL TECHNOLOGY ASSESSMENT

    EPA Science Inventory

    The study describes the state-of-the-art of controlling fumes escaping from blast furnace cast houses. Background information is based on: a study of existing literature; visits to blast furnaces in the U.S., Japan, and Europe; meetings with an ad hoc group of experienced blast f...

  3. Gram-range explosive blast scaling and associated materials response

    E-print Network

    Settles, Gary S.

    Gram-range explosive blast scaling and associated materials response M. J. Hargather1 , G. S. Laboratory-scale gram-range explosive blast testing of materials is shown to be feasible. Blast loading from different explosive compounds is coupled to a witness plate through the air by way of a shock wave of known

  4. Blast-furnace smelting with improved coke at OAO Zaporozhkoks

    Microsoft Academic Search

    A. P. Fomenko; V. I. Naboka; N. V. Krutas; M. E. Sharapov; V. N. Rubchevskii; Yu. A. Chernyshov; A. I. Kompaniets; A. V. Podlubnyi; E. T. Kovalev; I. V. Shul’ga; Yu. S. Kaftan

    2009-01-01

    As an experiment, coke from batteries 5 and 6 at OAO Zaporozhkoks is used in blast furnace 5 at Zaporozhstal, in order to\\u000a determine the influence of coke quality on blast-furnace operation. This research is associated with the prospects for coal-dust\\u000a injection into the blast furnace at OAO Zaporozhstal.

  5. Approach to Blast Wall Structure Computing in Ocean Engineering

    Microsoft Academic Search

    Qu Haifu; Li Xueguang

    2009-01-01

    With the rapid development of ocean engineering industry, researches on blast wall indicated that it is important and a key design for effective ocean engineering industry security production. However, existing theories of blast wall do not adequately address how and which approach is suitable for real production of ocean engineering. This paper presents a formal framework for blast wall in

  6. Blast wave transmission along rough-walled tunnels

    Microsoft Academic Search

    P. D. Smith; P. Vismeg; L. C. Teo; L. Tingey

    1998-01-01

    There is a sizeable body of published work relating to the transmission of blast waves along smooth tunnels of both simple and complex geometry though relatively little has been presented on the propagation of blast waves along tunnels with roughened walls. This paper presents the results of experimental studies carried out at small scale into the propagation of blast waves

  7. Electrohydraulic rock blasting for mining in urban areas

    Microsoft Academic Search

    Carlos Magno Muniz e Silva; Edson Guedes da Costa; Wildor Theodoro Hennies

    2001-01-01

    Conventional rock blasting promotes many negative environmental impacts including ground vibration, flying rock, air blast, and the emission of noise, dust and gases. An unconventional alternative process is the application of electrohydraulic principles. Electrohydraulic blasting is able to create a state of fracturing and rupture in the rock, almost instantly. A high current impulse generator produces the energy, without the

  8. Bayesian detection of acoustic muzzle blasts

    NASA Astrophysics Data System (ADS)

    Morton, Kenneth D., Jr.; Collins, Leslie

    2009-05-01

    Acoustic detection of gunshots has many security and military applications. Most gunfire produces both an acoustic muzzle-blast signal as well as a high-frequency shockwave. However some guns do not propel bullets with the speed required to cause shockwaves, and the use of a silencer can significantly reduce the energy of muzzle blasts; thus, although most existing commercial and military gunshot detection systems are based on shockwave detection, reliable detection across a wide range of applications requires the development of techniques which incorporate both muzzle-blast and shockwave phenomenologies. The detection of muzzle blasts is often difficult due to the presence of non-stationary background signals. Previous approaches to muzzle blast detection have applied pattern recognition techniques without specifically considering the non-stationary nature of the background signals and thus these techniques may perform poorly under realistic operating conditions. This research focuses on time domain modeling of the non-stationary background using Bayesian auto-regressive models. Bayesian parameter estimation can provide a principled approach to non-stationary modeling while also eliminating the stability concerns associated with standard adaptive procedures. Our proposed approach is tested on a synthetic dataset derived from recordings of actual background signals and a database of isolated gunfire. Detection results are compared to a standard adaptive approach, the least-mean squares (LMS) algorithm, across several signal to background ratios in both indoor and outdoor conditions.

  9. ARL Explosive Blast Bar Gauge Response Simulation

    NASA Astrophysics Data System (ADS)

    Sutherland, Gerrit; Boyle, Vincent; Benjamin, Richard

    2013-06-01

    Simulations allow us to optimize the design of a bar gauge. The incident blast wave imparts a wave that travels down the metal bar. Strain gauges positioned along the bar measure the strain produced by the bar wave, allowing determination of pressure and impulse at the bar face. The measured pressure history depends on the arrangement of the bar gauge. If a large metal plate surrounds the bar face, a reflected blast pressure is measured. If a metal fixture that forms a nozzle surrounds the bar face, the initial pressure will be the same as above. In time, release waves emanating from the nozzle edge will decrease the pressure at the bar face. The bar diameter and size of strain gauges control the time response or gauge bandwidth. CTH hydrocode simulations allow optimization of bar gauge features for various size explosive charges. The simulations predicted the response of the metal plate arrangement to a blast from a spherical composition C4 charge. The simulations predicted the proper metal plate diameter for a reflected pressure measurement. Other simulations compared the response of the bar gauge for both configurations (nozzle or plate surround) when subjected to the same blast loading. Pressure histories from simulations were compared to those from experiment and those predicted by the CONWEP blast code. The initial experimental and CONWEP pressures were in reasonable agreement.

  10. Modelling human eye under blast loading.

    PubMed

    Esposito, L; Clemente, C; Bonora, N; Rossi, T

    2015-01-01

    Primary blast injury (PBI) is the general term that refers to injuries resulting from the mere interaction of a blast wave with the body. Although few instances of primary ocular blast injury, without a concomitant secondary blast injury from debris, are documented, some experimental studies demonstrate its occurrence. In order to investigate PBI to the eye, a finite element model of the human eye using simple constitutive models was developed. The material parameters were calibrated by a multi-objective optimisation performed on available eye impact test data. The behaviour of the human eye and the dynamics of mechanisms occurring under PBI loading conditions were modelled. For the generation of the blast waves, different combinations of explosive (trinitrotoluene) mass charge and distance from the eye were analysed. An interpretation of the resulting pressure, based on the propagation and reflection of the waves inside the eye bulb and orbit, is proposed. The peculiar geometry of the bony orbit (similar to a frustum cone) can induce a resonance cavity effect and generate a pressure standing wave potentially hurtful for eye tissues. PMID:23521031

  11. Computational modeling of human head under blast in confined and open spaces: primary blast injury.

    PubMed

    Rezaei, A; Salimi Jazi, M; Karami, G

    2014-01-01

    In this paper, a computational modeling for biomechanical analysis of primary blast injuries is presented. The responses of the brain in terms of mechanical parameters under different blast spaces including open, semi-confined, and confined environments are studied. In the study, the effect of direct and indirect blast waves from the neighboring walls in the confined environments will be taken into consideration. A 50th percentile finite element head model is exposed to blast waves of different intensities. In the open space, the head experiences a sudden intracranial pressure (ICP) change, which vanishes in a matter of a few milliseconds. The situation is similar in semi-confined space, but in the confined space, the reflections from the walls will create a number of subsequent peaks in ICP with a longer duration. The analysis procedure is based on a simultaneous interaction simulation of the deformable head and its components with the blast wave propagations. It is concluded that compared with the open and semi-confined space settings, the walls in the confined space scenario enhance the risk of primary blast injuries considerably because of indirect blast waves transferring a larger amount of damaging energy to the head. PMID:23996897

  12. The Effect of Pleural Abrasion on the Treatment of Primary Spontaneous Pneumothorax: A Systematic Review of Randomized Controlled Trials

    PubMed Central

    Ming, Mo-yu; Cai, Shuang-qi; Chen, Yi-Qiang

    2015-01-01

    Background Pleural abrasion has been widely used to control the recurrence of primary spontaneous pneumothorax (PSP). However, controversy still exists regarding the advantages and disadvantages of pleural abrasion compared with other interventions in preventing the recurrence of PSP. Methods The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to December 15, 2014 to identify randomized controlled trials (RCTs) that compared the effects of pleural abrasion with those of other interventions in the treatment of PSP. The study outcomes included the PSP recurrence rate and the occurrence rate of adverse effects. Results Mechanical pleural abrasion and apical pleurectomy after thoracoscopic stapled bullectomy exhibited similarly persistent postoperative air leak occurrence rates (p = 0.978) and 1-year PSP recurrence rates (p = 0.821), whereas pleural abrasion led to reduced residual chest pain and discomfort (p = 0.001) and a smaller rate of hemothorax (p = 0.036) than did apical pleurectomy. However, the addition of minocycline pleurodesis to pleural abrasion did not reduce the pneumothorax recurrence rate compared with apical pleurectomy (3.8% for both procedures) but was associated with fewer complications. There was no statistical difference in the pneumothorax recurrence rate between mechanical pleural abrasion and chemical pleurodesis with minocycline on either an intention-to-treat basis (4 of 42 versus 0 of 42, p = 0.12; Fisher exact test) or after exclusions (2 of 40 versus 0 of 42, p = 0.24; Fisher exact test). Pleural abrasion plus minocycline pleurodesis also did not reduce the pneumothorax recurrence rate compared with pleural abrasion alone (p = 0.055). Moreover, pleural abrasion plus minocycline pleurodesis was associated with more intense acute chest pain. The postoperative overall recurrence rate in patients who underwent staple line coverage with absorbable cellulose mesh and fibrin glue was similar to that with mechanical abrasion after thoracoscopic bullectomy (13.8% vs. 14.2%, respectively; p = 0.555), but staple line coverage resulted in less postoperative residual pain than mechanical abrasion (0.4% vs.3.2%; p<0.0001). Pleural abrasion after thoracoscopic wedge resection did not decrease the recurrence of pneumothorax compared with wedge resection alone (p = 0.791), but the intraoperative bleeding and postoperative pleural drainage rates were higher when pleural abrasion was performed. Conclusions In addition to resulting in the same pneumothorax recurrence rate, thoracoscopic pleural abrasion with or without minocycline pleurodesis is safer than apical pleurectomy in the treatment of PSP. However, minocycline pleurodesis with or without pleural abrasion is not any more effective than pleural abrasion alone. Moreover, additional mechanical abrasion is not safer than additional staple line coverage with absorbable cellulose mesh and fibrin glue after thoracoscopic bullectomy because of increased postoperative pain. Additionally, pleural abrasion after thoracoscopic wedge resection should not be recommended for routine application due to the greater incidence of adverse effects than wedge resection alone. However, further large-scale, well-designed RCTs are needed to confirm the best procedure. PMID:26042737

  13. Evolution of blast wave profiles in simulated air blasts: experiment and computational modeling

    NASA Astrophysics Data System (ADS)

    Chandra, N.; Ganpule, S.; Kleinschmit, N. N.; Feng, R.; Holmberg, A. D.; Sundaramurthy, A.; Selvan, V.; Alai, A.

    2012-09-01

    Shock tubes have been extensively used in the study of blast traumatic brain injury due to increased incidence of blast-induced neurotrauma in Iraq and Afghanistan conflicts. One of the important aspects in these studies is how to best replicate the field conditions in the laboratory which relies on reproducing blast wave profiles. Evolution of the blast wave profiles along the length of the compression-driven air shock tube is studied using experiments and numerical simulations with emphasis on the shape and magnitude of pressure time profiles. In order to measure dynamic pressures of the blast, a series of sensors are mounted on a cylindrical specimen normal to the flow direction. Our results indicate that the blast wave loading is significantly different for locations inside and outside of the shock tube. Pressure profiles inside the shock tube follow the Friedlander waveform fairly well. Upon approaching exit of the shock tube, an expansion wave released from the shock tube edges significantly degrades the pressure profiles. For tests outside the shock tube, peak pressure and total impulse reduce drastically as we move away from the exit and majority of loading is in the form of subsonic jet wind. In addition, the planarity of the blast wave degrades as blast wave evolves three dimensionally. Numerical results visually and quantitatively confirm the presence of vortices, jet wind and three-dimensional expansion of the planar blast wave near the exit. Pressure profiles at 90° orientation show flow separation. When cylinder is placed inside, this flow separation is not sustained, but when placed outside the shock tube this flow separation is sustained which causes tensile loading on the sides of the cylinder. Friedlander waves formed due to field explosives in the intermediate-to far-field ranges are replicated in a narrow test region located deep inside the shock tube.

  14. IBPAT/OSHA Health and Safety Education Quiz Book. Painters, Abrasive Blasters, Tapers, Paint Makers, Floorcoverers.

    ERIC Educational Resources Information Center

    International Brotherhood of Painters and Allied Trades, Washington, DC.

    Designed for use by instructors using the "Health and Safety Education Book" (International Brotherhood of Painters and Allied Trades/Occupational Safety and Health Act), this book contains quizzes specifically for painters, abrasive blasters, tapers, paint makers, and floorcoverers. Quizzes included in the book focus on testing areas such as (1)…

  15. Abrasion, erosion and scuffing resistance of carbide and oxide ceramic thermal sprayed coatings for different applications

    Microsoft Academic Search

    G. Barbezat; A. R. Nicoll; A. Sickinger

    1993-01-01

    In the area of antiwear coatings, carbide-containing coatings and oxide ceramic coatings are applied using different thermal spray processes in the form of individual layers. In many industries these coatings have become technically significant on components where wear and friction can cause critical damage in the form of abrasion, erosion and scuffing together with corrosion. Carbide-containing and ceramic coatings have

  16. Theoretical analysis of the particle acceleration process in abrasive water jet cutting

    Microsoft Academic Search

    A. Tazibt; F. Parsy; N. Abriak

    1996-01-01

    In this paper, a general modelling for the acceleration process of abrasive particles in a high pressure water jet is presented. For this purpose, a new mathematical method is used which consists of the analytical resolution of the differential and non-linear equation of particle motion within a high speed waterjet flowing in a mixing nozzle (mixing tube). As a result,

  17. Platelet response to corneal abrasion is necessary for acute inflammation and efficient re-epithelialization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Adhesion molecules play a critical role in leukocyte emigration to wound sites, but differences are evident in different vascular beds. This study investigates the contributions of P-selectin to neutrophil emigration into the cornea following central epithelial abrasion. Methods: Re-epithel...

  18. Sand abrasion injury and plant survival in cotton seedlings of different ages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of crops are exposed to wind-blown soil abrasion injury each year and in many instances the damage is severe enough to require replanting. Little attention has been given to plant physiological or morphological factors that may lend resistance to, or enhance recovery from, wind-...

  19. Effect of different air-abrasion particles on metal-ceramic bond strength

    Microsoft Academic Search

    Tolga Külünk; Murat Kurt; Ça?r? Ural; ?afak Külünk; Seniha Baba

    2011-01-01

    Background\\/purposeChipping and delaminating of veneering ceramics are critical problems in the fabrication of metal-ceramic restorations. The purpose of this study was to evaluate the effect of different air-abrasion particles on the shear bond strength of a ceramic to nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloys.

  20. Apparatus for producing abrasion-proof coke forms from bituminous coal, brown coal or peat briquets

    Microsoft Academic Search

    H. Dungs; H. B. Koenigs; R. Kurtz; K. Lorenz

    1981-01-01

    Abrasion-proof coke forms are produced from bituminous coal, brown coal, or peat in the form of briquets, by preheating the briquets, dehydrating or predrying them, carbonizing them and then cooling them in at least three separate stages in which the briquets are dehydrated indirectly by subjecting them to indirect temperature conditions, producing a temperature gradient in the briquets. The briquets

  1. Method of producing abrasion-proof coke forms from bituminous coal, brown coal or peat briquets

    Microsoft Academic Search

    H. Dungs; H. B. Koenigs; R. Kurtz; K. Lorenz

    1981-01-01

    Abrasion-proof coke forms are produced from bituminous coal, brown coal, or peat in the form of briquets, by preheating the briquets, dehydrating or predrying them, carbonizing them and then cooling them in at least three separate stages in which the briquets are dehydrated indirectly by subjecting them to indirect temperature conditions, producing a temperature gradient in the briquets. The briquets

  2. Fracture and wear of composite materials in interaction with a stream of abrasive particles

    Microsoft Academic Search

    T. D. Karimbaev; Yu. A. Nozhnitskii; V. I. Gundarov; L. S. Rysin; V. G. Lyuttsai; I. A. Tarasov

    1980-01-01

    In the present work, an experimental study was made of the abrasive erosion of several composite materials and coatings based on polymers, carbon, and metals, and reinforced with glass, carbon, boron, and organic fibers, strips and cloths made of these fibers, whiskers, particles, and metal netting. For the sake of comparison, we also tested several metal alloys widely used in

  3. Influences of nanoscale abrasive suspensions on the polishing of fiber-optic connectors

    Microsoft Academic Search

    Ling Yin; Han Huang; Wei Kian Chen

    2005-01-01

    Effects of different nanoscale abrasive suspensions on the geometrical quality including fiber and ferrule surface roughness, fiber height, radius of curvature and apex offset, and the optical performance in terms of return and insertion losses in polishing of fiber connectors were investigated using a commercial fiber-connector polishing machine. Significant differences in geometrical and optical qualities were found among the suspensions

  4. Methods for the determination of platinum group elements originating from the abrasion of automotive catalytic converters

    Microsoft Academic Search

    László Bencs; Khaiwal Ravindra; René Van Grieken

    2003-01-01

    Anthropogenic emission of platinum group elements (PGEs) from the abrasion of automotive catalytic converters into the environment has significantly increased. However, the concentration level of these PGEs (i.e. Pd, Pt, Rh) is still very low in the nature. Accordingly, their determination and speciation in various environmental compartments appears to be a challenging task for analytical chemists. The present review gives

  5. Wear and surface roughness of current prosthetic composites after toothbrush\\/dentifrice abrasion

    Microsoft Academic Search

    Naomi Tanoue; Hideo Matsumura; Mitsuru Atsuta

    2000-01-01

    Statement of Problem: Surface changes of prosthetic composites caused by toothbrushing are known, although composite materials have been improved and are now widely used for various kinds of prosthetic restorations. Purpose: This study evaluated the influence of toothbrushing on abrasive wear and surface roughness of current prosthetic composites. Material and Methods: Seven composite materials (Artglass, Axis, Cesead II, Conquest Sculpture,

  6. Laser abrasion for cosmetic and medical treatment of facial actinic damage

    SciTech Connect

    David, L.M.; Lask, G.P.; Glassberg, E.; Jacoby, R.; Abergel, R.P.

    1989-06-01

    Previous studies have shown the carbon dioxide (CO/sub 2/) laser to be effective in the treatment of actinic cheilitis. After CO/sub 2/ laser abrasion, normal skin and marked cosmetic improvement of the lip were noted. In our study, twenty-three patients were treated with CO/sub 2/ laser abrasions for cosmetic improvement of facial lines and actinic changes. Pre- and postoperative histopathologic examinations were made on two patients. Preoperative examination of specimens from actinically damaged skin showed atypical keratinocytes in the basal layer of the epidermis, with overlying dense compact orthokeratosis and parakeratosis. Abundant solar elastosis was seen in the papillary dermis. Postoperative histologic specimens showed a normal-appearing epidermis with fibrosis in the papillary dermis and minimal solar elastosis (about four weeks after laser treatment). At present, various modalities are available for the regeneration of the aged skin, including chemical peels and dermabrasion. Significantly fewer complications were noted with CO/sub 2/ laser abrasion than with these methods. Thus, CO/sub 2/ laser abrasion can be useful in the cosmetic and medical treatment of the aged skin. Marked clinical and histologic improvement has been demonstrated.

  7. Scratching technique for the study and analysis of soil surface abrasion mechanism

    NASA Astrophysics Data System (ADS)

    Ta, Wanquan

    2007-11-01

    Aeolian abrasion is the most fundamental and active surface process that takes place in arid and semi-arid environments. Its nature is a wear process for wind blown grains impinging on a soil or sediment surface, which causes particles and aggregates to fracture from the soil surface through a series of plastic and brittle cracking deformation such as cutting, ploughing and brittle fracturing. Using a Universal Micro-Tribometer (UMT), a scratching test was carried out on six soil surfaces (sandy soil, sand loam, silt loam, loam, silt clay loam, and silt clay). The results indicate that traces of normal and tangential force vs. time show a jagged curve, which can reflect the plastic deformation and brittle fracturing of aggregates and particles of various sizes fractured from the soil surfaces. The jagged curve peaks, and the area enclosed underneath, may represent the bonding forces and bonding energies of some aggregates and grains on the soil surface, respectively. Connecting the scratching test with an impact abrasion experiment furthermore demonstrates that soil surface abrasion rates are proportional to the square of speeds of impacting particles and to the 2.6 power of mean soil grain size, and inversely proportional to the 1.5 power of specific surface abrasive energy or to the 1.7 power of specific surface hardness.

  8. NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural killer cells are lymphocytes of the innate immune system that have crucial cytotoxic and regulatory roles in adaptive immunity and inflammation. Herein, we consider a role for these cells in corneal wound healing. After a 2-mm central epithelial abrasion of the mouse cornea, a subset of clas...

  9. The effect of lubricants in single point scratching and abrasive machining of alumina and silicon nitride

    Microsoft Academic Search

    O. Desa; S. Bahadur

    2001-01-01

    The machining of ceramic materials is fraught with subsurface damage and low material removal rates because of their high hardness, low thermal conductivity and brittle behavior. With this in mind, the subsurface damage and material removal in single point scratching and abrasive machining of alumina and silicon nitride were studied. The lubricants were selected based on their potential for high

  10. Abrasive wear behavior of heat-treated ABC-silicon carbide

    SciTech Connect

    Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da; Ritchie, Robert O.; De Jonghe, Lutgard C.

    2002-06-17

    Hot-pressed silicon carbide, containing aluminum, boron, and carbon additives (ABC-SiC), was subjected to three-body and two-body wear testing using diamond abrasives over a range of sizes. In general, the wear resistance of ABC-SiC, with suitable heat treatment, was superior to that of commercial SiC.

  11. Blast noise impacts on sleep

    NASA Astrophysics Data System (ADS)

    Nykaza, Edward T.; Pater, Larry L.

    2005-04-01

    Firing large guns during the hours of darkness is essential to combat readiness for the military. At the same time most people are particularly sensitive to noise when sleeping or trying to fall asleep. Laboratory studies done by Griefahn [J. Sound and Vib. 128, 109-119 (1989)] and Luz [see Luz et al., ERDC/CERL, TR-04-26 (2004)] suggest that a time period at night may exist where people are more tolerant to large weapon impulse noise (blast noise) and therefore, are less likely to be awakened from noise events. In the fall of 2004, a field study was conducted around a military installation to determine if such a time period(s) exists. Noise monitors were set up inside and outside of residents homes to record noise levels from live military training activities and actimeters were worn by participants sleeping their natural environment to measure sleep disturbance and awakening. The method and results of this study will be presented. [Work supported by US Army Engineer Research and Development Center CERL.

  12. Computation of blast wave-obstacle interactions

    NASA Technical Reports Server (NTRS)

    Champney, J. M.; Chaussee, D. S.; Kutler, P.

    1982-01-01

    Numerical simulations of the interaction of a planar blast wave with various obstacles are presented. These obstacles are either ground structures or vehicles flying in the atmosphere. For a structure on the ground, the blast wave encounter is side-on, while for the flying vehicles the encounter is either head-on or oblique. Second-order accurate, finite-difference, and shock-capturing procedures are employed to solve the two-dimensional, axisymmetric, and three-dimensional unsteady Euler equations. Results are presented for the flow field consisting of blast wave striking obstacles that are at rest, moving subsonically and moving supersonically. Comparison of the numerical results with experimental data for a configuration at rest substantiates the validity of this approach and its potential as a flow analysis tool.

  13. Single Pass Streaming BLAST on FPGAs*†

    PubMed Central

    Herbordt, Martin C.; Model, Josh; Sukhwani, Bharat; Gu, Yongfeng; VanCourt, Tom

    2008-01-01

    Approximate string matching is fundamental to bioinformatics and has been the subject of numerous FPGA acceleration studies. We address issues with respect to FPGA implementations of both BLAST- and dynamic-programming- (DP) based methods. Our primary contribution is a new algorithm for emulating the seeding and extension phases of BLAST. This operates in a single pass through a database at streaming rate, and with no preprocessing other than loading the query string. Moreover, it emulates parameters turned to maximum possible sensitivity with no slowdown. While current DP-based methods also operate at streaming rate, generating results can be cumbersome. We address this with a new structure for data extraction. We present results from several implementations showing order of magnitude acceleration over serial reference code. A simple extension assures compatibility with NCBI BLAST. PMID:19081828

  14. Paint removal using wheat starch blast media

    NASA Astrophysics Data System (ADS)

    Foster, Terry; Oestreich, John

    1993-03-01

    A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of cracks confirms better crack visibility with wheat starch media versus Type V or Type II plastic media. Testing of wheat starch media in several composite test programs, including fiberglass, Kevlar, and graphite-epoxy composites, showed no fiber damage. Process developments and production experience at the first U.S. aircraft stripping facility are also reviewed. Corporate and regional aircraft are being stripped in this three nozzle dry blast hanger.

  15. The blast wave mitigation effects of a magnetogasdynamic decelerator

    SciTech Connect

    Baty, Roy S [Los Alamos National Laboratory; Lundgren, Ronald G [APPLIED RESEARCH ASSOCIATES; Tucker, Don H [UNIV OF UTAH

    2009-01-01

    This work computes shock wave jump functions for viscous blast waves propagating in a magnetogasdynamic decelerator. The decelerator is assumed to be a one-dimensional channel with sides that are perfect conductors. An electric field applied on the walls of the channel produces a magnetogasdynamic pump, which decelerates the flow field induced by a blast wave. The blast wave jump functions computed here are compared to magnetogasdynamic results for steady supersonic channel flow to quantify potential blast mitigation effects. Theoretical shock wave jump functions are also presented for inviscid blast waves propagating in a one-dimensional channel with an electromagnetic field.

  16. BLAST: a more efficient report with usability improvements.

    PubMed

    Boratyn, Grzegorz M; Camacho, Christiam; Cooper, Peter S; Coulouris, George; Fong, Amelia; Ma, Ning; Madden, Thomas L; Matten, Wayne T; McGinnis, Scott D; Merezhuk, Yuri; Raytselis, Yan; Sayers, Eric W; Tao, Tao; Ye, Jian; Zaretskaya, Irena

    2013-07-01

    The Basic Local Alignment Search Tool (BLAST) website at the National Center for Biotechnology (NCBI) is an important resource for searching and aligning sequences. A new BLAST report allows faster loading of alignments, adds navigation aids, allows easy downloading of subject sequences and reports and has improved usability. Here, we describe these improvements to the BLAST report, discuss design decisions, describe other improvements to the search page and database documentation and outline plans for future development. The NCBI BLAST URL is http://blast.ncbi.nlm.nih.gov. PMID:23609542

  17. The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way

    PubMed Central

    Tellefsen, Georg; Johannsen, Annsofi; Liljeborg, Anders

    2013-01-01

    Objective. To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively. Materials and methods. Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface roughness value (Ra-value) and also a volume loss value were calculated from the profilometer measurements. These values were then correlated to each other. An unpaired t-test for the difference in the abrasion values between the toothpastes and the abrasion values over time was used. Results. The polishing paste RDA® 170 yielded higher Ra-values than RDA 250®, both after 1 and 6 h of brushing (1.01 ± 0.22 and 8.99 ± 1.55 compared to 0.63 ± 0.26 and 7.83 ± 5.89, respectively) as well as volume loss values (3.71 ± 0.17 and 20.20 ± 2.41 compared to 2.15 ± 1.41 and 14.79 ± 11.76, respectively), thus poor correlations between the RDA and Ra and Volume loss values were shown. Among the toothpastes, Apotekets® showed the highest Ra value after 1 h of brushing and Pepsodent® whitening after 6 h of brushing. Pepsodent® whitening also showed the highest volume loss values, both after 1 and 6 h of brushing. Conclusion. This study emphasizes the importance of not only considering the RDA value, but also a roughness value, when describing the abrasivity of a toothpaste. Furthermore, it can be concluded that so called ‘whitening' toothpastes do not necessarily have a higher abrasive effect than other toothpastes. PMID:22746180

  18. Experimental investigation on the effect of abrasive grain size on the lapping uniformity of a sapphire wafer

    NASA Astrophysics Data System (ADS)

    Wen, Donghui; Wang, Zhiwei; Zhang, Kehua

    2009-05-01

    Experiments are taken to investigate the effect of abrasive grain size on the lapping uniformity of sapphire wafer, macro and micro surface profiles are measured and compared by contact and contactless measurement methods. For W14 carbide boron abrasive lapping process, rolling and extruding effects are the main material removal mechanism and leaves high density micro-crack on the lapped sapphire surface. On the other hand, W3.5 carbide boron abrasive grain performs a ductile cutting process for material remove process under the same operated parameters, only scratch on sapphire surface can be viewed by AFM. Experimental results show that abrasive grain size has a great effect on the surface integrity of the lapped sapphire, charging status of abrasive grain into the lapping plate and its effect on the surface integrity should be considered when choosing the abrasive grain size for precision lapping process. Lapping uniformity both for macro and micro level, roughness and flatness of sapphire wafer can be achieved by using W3.5 carbide boron abrasive grain and acceptable by pre-polishing process.

  19. The design, implementation, and evaluation of mpiBLAST

    SciTech Connect

    Darling, A. E. (Aaron E.); Carey, L. (Lucas); Feng, W. C. (Wu-Chun)

    2003-01-01

    mpiBLAST is an open-source parallelization of BLAST that achieves superlinear speed-up by segmenting a BLAST database and then having each node in a computational cluster search a unique portion of the database. Database segmentation permits each node to search a smaller portion of the database, eliminating disk I/O and vastly improving BLAST performance. Because database segmentation does not create heavy communication demands, BLAST users can take advantage of low-cost and efficient Linux cluster architectures such as the bladed Beowulf. In addition to presenting the software architecture of mpiBLAST we present a detailed performance analysis of mpiBLAST to demonstrate its scalability.

  20. LTC American`s, Inc. vacuum blasting machine: Baseline report

    SciTech Connect

    NONE

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC 1073 Vacuum Blasting Machine uses a high-capacity, direct-pressure blasting system which incorporates a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast. It incorporates a vacuum system which removes dust and debris from the surface as it is blasted. The safety and health evaluation during the testing focused on two main areas of exposure: dust and noise.

  1. Characterizing explosives and blasting emissions

    SciTech Connect

    Johnson, M.B. [Army Dugway Proving Ground, UT (United States); Bacon, D.P. [ECO, L.C., Salt Lake City, UT (United States)

    1995-12-31

    With the advance of science, rise of public interest in environmental matters, and continuing erosion of air quality, Federal and state regulators are demanding an increasing complex array of data concerning emissions produced by burning and detonating energetic materials. The US Department of Defense, one of the world`s largest consumers of energetic materials, now must characterize combustion products resulting from open burning/open detonation disposal operations. The catch-all phrase ``below detection limits`` no longer satisfies the regulators who now want testing to delve into the ppt level for volatile organic compounds and ppt level for semivolatile organic compounds. Regulators are also expanding their scope of interest and may soon be asking for emissions data on training operations such as artillery firing. Providing this type of information is no longer an impossibility. The Army, as the single manager of conventional munitions for the three military services, anticipated the tightening of data requirements and in the mid-1980s funded a study into technologies to characterize emissions produced by open-air destruction of propellants, explosives, and pyrotechnics. This study, conducted in cooperation with the US Environmental Protection Agency, has resulted in a unique testing system which gathers data from small detonations and burns and can accurately scale the data to allow characterizing combustion products of field open-burning/open-detonation disposal operations. The system and its technologies apply to other operations involving energetic materials. This paper describes the system (known as the BangBox Testing System), its component technologies, emerging results, and potential applications in the explosives and blasting industries.

  2. Durability of traditional plasters with respect to blast furnace slag-based plaster

    SciTech Connect

    Cerulli, T.; Pistolesi, C.; Maltese, C.; Salvioni, D

    2003-09-01

    Blast furnace slag is a residue of steel production. It is a latent hydraulic binder and is normally used to improve the durability of concrete and mortars. Slag could be also used as rendering mortar for masonry and old buildings. Today, cement and hydraulic lime are the most popular hydraulic binders used to make plasters. They are characterised by a low durability when exposed to the action of chemical and physical agents. The aim of this study was to provide a comparison between the physical-mechanical properties of some renders made with ordinary Portland cement, hydraulic lime, or slag. Furthermore, an investigation was carried out to analyse mortar resistance to several aggressive conditions like acid attack, freezing and thawing cycles, abrasion, sulphate aggression, cycles in ultraviolet screening device, and salt diffusion. The specimens, after chemical attack, have been characterised from the chemical-physical [specific surface according to the BET (Brunauer-Emmet-Teller) method], crystal-chemical (X-ray diffraction, XRD), and morphological (scanning electron microscopy, SEM) points of view.

  3. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards

    NASA Technical Reports Server (NTRS)

    Street, Kenneth W., Jr.; Kobrick, Ryan L.; Klaus, David M.

    2013-01-01

    Abrasion of mechanical components and fabrics by soil on Earth is typically minimized by the effects of atmosphere and water. Potentially abrasive particles lose sharp and pointed geometrical features through erosion. In environments where such erosion does not exist, such as the vacuum of the Moon, particles retain sharp geometries associated with fracturing of their parent particles by micrometeorite impacts. The relationship between hardness of the abrasive and that of the material being abraded is well understood, such that the abrasive ability of a material can be estimated as a function of the ratio of the hardness of the two interacting materials. Knowing the abrasive nature of an environment (abrasive)/construction material is crucial to designing durable equipment for use in such surroundings. The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed Zone of Interaction (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width. The ZOI has been found to be at least twice the size of a standard width measurement; in some cases, considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for de tailed analysis. Documenting additional changes to various surface roughness par ameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Further - more, by investigating the use of custom scratch tips for specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized manner, and not just by scratch width alone, is reinforced. This benefit is made apparent when a tip creates an intricate contour having multiple peaks and valleys within a single scratch. The current innovation consists of a software- driven method of quantitatively evaluating a scratch profile. The profile consists of measuring the topographical features of a scratch along the length of the scratch instead of the width at one location. The digitized profile data is then fed into software code, which evaluates enough metrics of the scratch to reproduce the scratch from the evaluated metrics. There are three key differences between the current art and this innovation. First, scratch width does not quantify how far from the center of the scratch damage occurs (ZOI). Second, scratch width does not discern between material displacement and material removal from the scratch. Finally, several scratches may have the same width but different zones of interactions, different displacements, and different material removals. The current innovation allows quantitative assessment of all three.

  4. Relationship between Los Angeles attrition test and Nordic abrasion test of volcanic rocks

    NASA Astrophysics Data System (ADS)

    Krutilová, Kate?ina; Prikryl, Richard

    2015-04-01

    Various volcanic rocks contribute significantly to the production of crushed stone in the Czech Republic. When used for road surfacing, results of Los Angeles attrition test (LA value below 25 or 30 depending on the mode of use) together with polished stone value are required. In the recent study, we have focused on the search for possible correlation between results obtained by Los Angeles attrition test and Nordic abrasion test, a test widely employed in Scandinavia. For the experimental study, a set of volcanic rocks from 36 active quarries was used. The rocks under study represent range of volcanic rocks from ultrabasic to acid members, formed form Neoproterozoic to Tertiary. The most favourable results of Los Angeles attrition test (i.e. the lowest LA values) were obtained for basalts (range of values 9.4-19.4) and spilites (range of values 8.4-14.9) which are in fact Neoproterozoic to Late Palaeozoic basalts affected by low grade metamorphism. Nordic abrasion test exhibited much broader range of values (6.4 to 36.9) with average value at 15.2 for basalts, resulting in weak coefficient of determination (0.19). . On contrary, narrow range of values from Nordic abrasion test of spilites (7.2-15.9), very similar to the range of LA values, is reflect in higher coefficient of determination (0.56). On contrary, the least favourable properties (LA values 12.3-29.2, Nordic abrasion 16.8-43.3) have been observed for a group of basic to intermediate rocks classified in older literature as melaphyres and diabases (ranging from basalts to trachyndesites and/or trachybasalts) of Palaeozoic age. However, in this specific group of volcanic rocks, the highest coefficient of determination (0.89) between both tests has been achieved. For volcanic rocks exhibiting acid composition (rhyolites and quartz porphyry), coefficient of determination between LA values (15.1-19.3) and Nordic abrasion test (7.3-21.9) is weak (0.42). The weakest relationship between LA values (14.9-23.8) and Nordic abrasion test results (14.2-17.6) have been observed for group of phonolites, with value of coefficient of determination 0.12. Despite the similar principle of both test methods (i.e. the mechanism of deterioration of aggregate particles during the test), the results seems to be variable for rocks of similar mode of formation. The differences between individual groups of volcanic rocks can be partially explained by variable rock macro- and microfabrics that significantly affect their rock physical properties.

  5. Pipeline response to blasting in rock

    Microsoft Academic Search

    Esparza

    1991-01-01

    Twenty-one highway construction blasts were used to record pipeline data from production shots that consisted of small explosive arrays with delays among the explosive holes. A 30-in pipe section and a 12-in. pipeline in the vicinity of the highway construction work were instrumented with strain gages. The data provided an opportunity to determine if the estimating equations and techniques developed

  6. Rice blast evaluation of newly introduced germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic resistance to the rice blast fungus, Magnaporthe oryzae (anamorph Pyricularia grisea oryzae) was identified in newly introduced rice germplasm through quarantine when tested in artificially inoculated greenhouse and field nursery tests during the 2007 growing season. Of 229 accessions, 31 we...

  7. Global efforts in managing rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by the fungus Magnaporthe oryzae is a major destructive disease threatening global food security. Resistance (R) genes to M. oryzae are effective in preventing infections by strains of M. oryzae carry the corresponding avirulence (AVR) genes. Effectiveness of genetic resist...

  8. Air blast effects on concrete walls

    Microsoft Academic Search

    C. A. Kot; P. Turula

    1976-01-01

    The effects of airblast due to explosive detonation in close proximity of a concrete wall are investigated analytically. Estimates are obtained both for the spalling of the back-face of the concrete wall and for the overall wall response produced by the total impulsive load of the air blast. Assuming elastic wave propagation in the concrete wall, it is found that

  9. Dangers of Toxic Fumes from Blasting

    Microsoft Academic Search

    Richard J. Mainiero; Marcia L. Harris

    This paper reviews the potential hazards posed by the toxic fumes produced by detonating explosives in surface m ining and construction operations. Blasting operations produce both toxic and nontoxic gaseous products; the toxic being mainly carbon monoxide (CO) and the oxides of nitrogen (NOx). The quantity of toxic gases produced by an explosive is affected by formulation, confinement, age of

  10. Heat transfer analysis of blast furnace stave

    Microsoft Academic Search

    Lijun Wu; Xun Xu; Weiguo Zhou; Yunlong Su; Xiaojing Li

    2008-01-01

    The three-dimensional mathematical model of temperature and thermal stress field of the blast furnace stave is built. The radiation heat transmitted from solid materials (coke and ore) to inner surface of the stave, which has been neglected by other studies, is taken into account. The cast steel stave is studied and the finite element method is used to perform the

  11. Blast waves and how they interact with structures.

    PubMed

    Cullis, I G

    2001-02-01

    The paper defines and describes blast waves, their interaction with a structure and its subsequent response. Explosions generate blast waves, which need not be due to explosives. A blast wave consists of two parts: a shock wave and a blast wind. The paper explains how shock waves are formed and their basic properties. The physics of blast waves is non-linear and therefore non-intuitive. To understand how an explosion generates a blast wave a numerical modelling computer code, called a hydrocode has to be employed. This is briefly explained and the cAst Eulerian hydrocode is used to illustrate the formation and propagation of the blast wave generated by a 1 kg sphere of TNT explosive detonated 1 m above the ground. The paper concludes with a discussion of the response of a structure to a blast wave and shows that this response is governed by the structures natural frequency of vibration compared to the duration of the blast wave. The basic concepts introduced are illustrated in a second simulation that introduces two structures into the blast field of the TNT charge. PMID:11307674

  12. 22 CFR 121.11 - Military demolition blocks and blasting caps.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Military demolition blocks and blasting caps. 121.11 Section 121...Articles § 121.11 Military demolition blocks and blasting caps. Military demolition blocks and blasting caps referred to in...

  13. 22 CFR 121.11 - Military demolition blocks and blasting caps.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Military demolition blocks and blasting caps. 121.11 Section 121...Articles § 121.11 Military demolition blocks and blasting caps. Military demolition blocks and blasting caps referred to in...

  14. Defining an Abrasion Index for Lunar Surface Systems as a Function of Dust Interaction Modes and Variable Concentration Zones

    NASA Technical Reports Server (NTRS)

    Kobrick, Ryan L.; Klaus, David M.; Street, Kenneth W., Jr.

    2010-01-01

    Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and subcategorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a single particle or asperity slides across a given surface removing or displacing material. Three-body abrasion occurs when multiple particles interact with a solid surface, or in between two surfaces, allowing the abrasives to freely rotate and interact with the material(s), leading to removal or displacement of mass. Different modes of interaction are described in this paper along with corresponding types of tests that can be utilized to evaluate each configuration. In addition to differential modes of abrasion, variable concentrations of dust in different zones can also be considered for a given system design and operational protocol. These zones include: (1) outside the habitat where extensive dust exposure occurs, (2) in a transitional zone such as an airlock or suitport, and (3) inside the habitat or spacesuit with a low particle count. These zones can be used to help define dust interaction frequencies, and corresponding risks to the systems and/or crew can be addressed by appropriate mitigation strategies. An abrasion index is introduced that includes the level of risk, R, the hardness of the mineralogy, H, the severity of the abrasion mode, S, and the frequency of particle interactions, F.

  15. Cubic boron nitride: Tools and abrasives. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1994-01-01

    The bibliography contains citations of selected patents concerning materials of cubic boron nitride (CBN) for machine tools and superhard abrasives. Included are methods of producing CBN compacts and abrasive structures for cutting tools, tool inserts, grinding wheels, wire drawing dies, gears, and drill bits. Bonding methods on various substrates are also presented. (Contains a minimum of 244 citations and includes a subject term index and title list.)

  16. Defining an abrasion index for lunar surface systems as a function of dust interaction modes and variable concentration zones

    NASA Astrophysics Data System (ADS)

    Kobrick, Ryan L.; Klaus, David M.; Street, Kenneth W.

    2011-11-01

    Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and sub-categorically by physical interactions of compression, rolling, sliding, and bending representing specific applications within the system. Two-body abrasion occurs when a single particle or asperity slides across a given surface removing or displacing material. Three-body abrasion occurs when multiple particles interact with a solid surface, or in between two surfaces, allowing the abrasives to freely rotate and interact with the material(s), leading to removal or displacement of mass. Different modes of interaction are described in this paper along with corresponding types of tests that can be utilized to evaluate each configuration. In addition to differential modes of abrasion, variable concentrations of dust in different zones can also be considered for a given system design and operational protocol. These zones include (1) outside the habitat where extensive dust exposure occurs, (2) in a transitional zone such as an airlock or suitport, and (3) inside the habitat or spacesuit with a low particle count. These zones can be used to help define dust interaction frequencies, and corresponding risks to the systems and/or crew can be addressed by appropriate mitigation strategies. An abrasion index is introduced that includes the level of risk, R, the hardness of the mineralogy, H, the severity of the abrasion mode, S, and the frequency of particle interactions, F.

  17. Characterization of fillers used in abrasive articles by means of inverse gas chromatography and principal component analysis

    Microsoft Academic Search

    Adam Voelkel; Beata Strzemiecka

    2007-01-01

    Abrasive articles consists of cutting particle—very often from electrocorundum, filler—inorganic compound, e.g. potassium fluoroborate or cryolite, binder—novolak resin and wetting agent—resol. The most important stages during manufacturing of grinding tools are: the coverage of the abrasive by wetting agent and proper hardening. The fillers play a very important role during the work of the grinding tools—they collect the heat and

  18. Analysis of composite type and different sources of polymerization light on in vitro toothbrush\\/dentifrice abrasion resistance

    Microsoft Academic Search

    N Tanoue; H Matsumura; M Atsuta

    2000-01-01

    Objectives: This study examined toothbrush\\/dentifrice abrasion of a photo-activated prosthetic composite (dentin and enamel variations) for the purpose of evaluating the influence of polymerization sources on abrasive wear.Methods: A photo-activated prosthetic composite material (Artglass) was assessed. Dentin and enamel variations were polymerized using a proprietary photo-curing unit with two xenon stroboscopic lamps (UniXS), and other enamel specimens were polymerized either

  19. Mechanisms of microhole formation on glasses by an abrasive slurry jet

    SciTech Connect

    Wang, J.; Nguyen, T.; Pang, K. L. [School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia)

    2009-02-15

    Abrasive jet micromachining is considered as a promising precision processing technology for brittle materials such as silicon substrates and glasses that are increasingly used in various applications. In this paper, the mechanisms of microhole formation on brittle glasses by an abrasive slurry jet are studied based on the viscous flow and erosion theories. It is shown that the hole cross section is characterized by a ''W'' shape and can be classified into three zones caused, respectively, by jet direct impact, viscous flow, and turbulent flow induced erosion. An analysis of the surface morphology shows that ductile-mode erosion is dominant. The effect of process parameters on material removal is studied which shows that increasing the pressure and erosion time increases the hole depth, but has little effect on the hole diameter.

  20. Abrasive water suspension jet -- A multifunctional working tool for underwater applications

    SciTech Connect

    Brandt, C.; Louis, H.; Meier, G.; Tebbing, G. [Univ. of Hannover (Germany). Inst. of Material Science

    1995-12-31

    It is the aim of the paper to show the possibilities of Abrasive Water Suspension Jets (AWSJ) for underwater machining tasks in the offshore industry and other deep sea operations. The AWSJ is a remote-controllable and multifunctional tool for different underwater purposes like maintenance and repair as well as salvage, removal and decommissioning. Therefore it is possible to clean structures from rust and marine growth, to remove concrete and other functional coatings, to cut through different materials as well as composite materials and also to carry out the preparation for repair welding. First the paper will give some basic information about Abrasive Water Jets under water and about the equipment to produce AWSJ. Afterwards the possibilities of jet generation for cutting (round jet), cleaning and material removal (flat jet) and multifunctional operation will be demonstrated. Test results which were carried out under water will be presented. The influence of relevant parameters on processing efficiency is given and discussed.

  1. M"ossbauer study of corrosion and abrasion products in oil transporting pipes

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Perez Mazariego, Jose Luis; Marquina, Vivianne; Marquina, Ma. Luisa; Ridaura, Rosalia; Martinez, Lorenzo

    2012-02-01

    It is known that one of the main technological problems in carbon steel oleoducts is the corrosion produced by different substances, such as water, carbon dioxide, sulfur, and microorganisms. In addition, if in such mixture there is sand, aggressive sludge can be form that abrasions material from the oleoduct. A room temperature M"ossbauer study of corroded material taken from different sites of oleoducts is presented. Most of the M"ossbauer spectra reveal the presence of nanoparticles, indicating that in these pipes the abrasion problem is severe. A preliminary identification of the oxidized samples suggests the presence of magnetite, and some Iron hydroxides. Further studies are in course in order to identify unambiguously the products present in the corroded materials.

  2. Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics

    PubMed Central

    Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

    2013-01-01

    Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8?kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect. PMID:24135813

  3. Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics.

    PubMed

    Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

    2013-01-01

    Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8?kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect. PMID:24135813

  4. Abrasive wear behavior of P/M titanium metal-matrix composites

    SciTech Connect

    Alman, D.E.; Hawk, J.A.; Simmons, J.W.

    1997-01-01

    The abrasive wear behavior of titanium metal-matrix composites produced by powder metallurgical techniques was studied. Ti powder was mixed with 0, 20, or 40 volume percent (v%) TiB2, TiC, TiN, SiC, an B4C powder to produce a composite powder blend. The blends were consolidated by hot-pressing at 1200° C and 20 MPa for 2 hours. Also a series of Ti-TiB2 composites was consolidated by press and sinter techniques. Two-body abrasive wear resistance, of the composites worn against either SiC or garnet particles, was evaluated using a pin-on-drum apparatus. The wear behavior of the composites was correlated to the physical properties (e.g., microstructure, sintered density, hardness, strength) of the composites, and compared to the behavior of conventional cast adn wrought Ti and other alloys.

  5. Multivariable Modeling of Impact-Abrasion Wear Rates in Metal Matrix-Carbide Composite Materials

    Microsoft Academic Search

    E. Badisch; S. Ilo; R. Polak

    2009-01-01

    Carbide-matrix hardfacings reinforced with spherical and angular particles of different size and density have been investigated\\u000a about correlation of their specific material parameters—especially matrix hardness and microstructure parameters—with the\\u000a wear rates in continuous impact abrasion test (CIAT). For this study, 12 different hardfacings have been characterized by\\u000a the quantitative metallographic method for determination of specific structural parameters, such as the

  6. Waterjet and abrasive waterjet surface treatment of titanium: a comparison of surface texture and residual stress

    Microsoft Academic Search

    D. Arola; M. L. McCain; S. Kunaporn; M. Ramulu

    2002-01-01

    In this study, commercially pure titanium (cpTi) and a titanium alloy (Ti6Al4V) were subjected to waterjet (WJ) peening and abrasive waterjet (AWJ) peening surface treatments. The texture and in-plane biaxial residual stress of the treated surfaces were quantified using contact profilometry and X-ray diffraction, respectively. Regardless of the specific process conditions, the surface residual stresses resulting from WJ and AWJ

  7. AN EXAMINATION OF ABRASIVE WATERJET PEENING WITH ELASTIC PRESTRESS AND THE EFFECTS OF BOUNDARY CONDITIONS

    Microsoft Academic Search

    Balaji Sadasivam; Dwayne Arola

    2012-01-01

    Abrasive Waterjet Peening (AWJP) has emerged as a potentially viable method of surface treatment for components requiring compressive residual stress and a rough surface texture. In the present investigation the residual stress distributions resulting from AWJP of Ti6Al4V with load and displacement control flexure pre-stress were compared. An experimental evaluation was conducted to quantify the variations in the residual stress

  8. Mathematical model for abrasive suspension jet cutting based on orthogonal test design

    Microsoft Academic Search

    Gui-hua Hu; Wen-hua Zhu; Hong-xia Cai; Chong Xu; Yu-jie Bai; Jun Cheng; Jin Yuan; Tao Yu

    2009-01-01

    This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive\\u000a suspension jet (ASJ) cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless\\u000a steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerf ratio\\u000a of the bottom width to the

  9. MULTI-OBJECTIVE OPTIMIZATION OF ABRASIVE FLOW MACHINING PROCESSES USING POLYNOMIAL NEURAL NETWORKS AND GENETIC ALGORITHMS

    Microsoft Academic Search

    M. Ali-Tavoli; N. Nariman-Zadeh; A. Khakhali; M. Mehran

    2006-01-01

    Abrasive flow machining (AFM) is an economic and effective non-traditional machining technique, which is capable of providing excellent surface finish on difficult to approach regions on a wide range of components. With this method, it has become possible to substitute various time-consuming deburring and polishing operations that had often lead to non-reproducible results. In this paper, group method of data

  10. Three-body abrasive wear behaviour of carbon and glass fiber reinforced epoxy composites

    Microsoft Academic Search

    B. Suresha; G. Chandramohan; Siddaramaiah; P. Samapthkumaran; S. Seetharamu

    2007-01-01

    Three-body abrasive wear behaviour of carbon–epoxy (C–E) and glass–epoxy (G–E) composites has been investigated. The effect of abrading distance, viz., 270, 540, 810 and 1080m and different loads of 22 and 32N at 200rpm have been studied. The wear volume loss and specific wear rate as a function of load and abrading distance were determined. The wear volume loss increases

  11. Abrasive Wear Resistance of Tool Steels Evaluated by the Pin-on-Disc Testing

    NASA Astrophysics Data System (ADS)

    Bressan, José Divo; Schopf, Roberto Alexandre

    2011-05-01

    Present work examines tool steels abrasion wear resistance and the abrasion mechanisms which are one main contributor to failure of tooling in metal forming industry. Tooling used in cutting and metal forming processes without lubrication fails due to this type of wear. In the workshop and engineering practice, it is common to relate wear resistance as function of material hardness only. However, there are others parameters which influences wear such as: fracture toughness, type of crystalline structure and the occurrence of hard precipitate in the metallic matrix and also its nature. In the present investigation, the wear mechanisms acting in tool steels were analyzed and, by normalized tests, wear resistance performance of nine different types of tool steels were evaluated by pin-on-disc testing. Conventional tool steels commonly used in tooling such as AISI H13 and AISI A2 were compared in relation to tool steels fabricated by sintering process such as Crucible CPM 3V, CPM 9V and M4 steels. Friction and wear testing were carried out in a pin-on-disc automated equipment which pin was tool steel and the counter-face was a abrasive disc of silicon carbide. Normal load of 5 N, sliding velocity of 0.45 m/s, total sliding distance of 3000 m and room temperature were employed. The wear rate was calculated by the Archard's equation and from the plotted graphs of pin cumulated volume loss versus sliding distance. Specimens were appropriately heat treated by quenching and three tempering cycles. Percentage of alloying elements, metallographic analyses of microstructure and Vickers microhardness of specimens were performed, analyzed and correlated with wear rate. The work is concluded by the presentation of a rank of tool steel wear rate, comparing the different tool steel abrasion wear resistance: the best tool steel wear resistance evaluated was the Crucible CPM 9V steel.

  12. Effects of Different Lasers and Particle Abrasion on Surface Characteristics of Zirconia Ceramics

    PubMed Central

    Arami, Sakineh; Tabatabae, Masoume Hasani; Namdar, Seyedeh Fatemeh; Chiniforush, Nasim

    2014-01-01

    Objective: The aim of this study was to assess the surface of yttrium-stabilized tetragonal zirconia (Y-TZP) after surface treatment with lasers and airborne-particle abrasion. Materials and Methods: First, 77 samples of presintered zirconia blocks measuring 10 × 10 × 2 mm were made, sintered and polished. Then, they were randomly divided into 11 groups (n=7) and received surface treatments namely, Er:YAG laser irradiation with output power of 1.5, 2 and 2.5 W, Nd:YAG laser with output power of 1.5, 2 and 2.5 W, CO2 laser with output power of 3, 4 and 5 W, AL2O3 airborne-particle abrasion (50?) and no treatment (controls). Following treatment, the parameters of surface roughness such as Ra, Rku and Rsk were evaluated using a digital profilometer and surface examination was done by SEM. Results: According to ANOVA and Tukey’s test, the mean surface roughness (Ra) after Nd:YAG laser irradiation at 2 and 2.5 W was significantly higher than other groups. Roughness increased with increasing output power of Nd:YAG and CO2 lasers. Treated surfaces by Er:YAG laser and air abrasion showed similar surface roughness. SEM micrographs showed small microcracks in specimens irradiated with Nd:YAG and CO2 lasers. Conclusion: Nd:YAG laser created a rough surface on the zirconia ceramic with many microcracks; therefore, its use is not recommended. Air abrasion method can be used with Er:YAG laser irradiation for the treatment of zirconia ceramic. PMID:24910700

  13. Energy Dissipation Control in Hydro-Abrasive Machining Using Quantitative Acoustic Emission

    Microsoft Academic Search

    R. Kovacevic; A. W. Momber; R. S. Mohen

    2002-01-01

    The efficiency and product quality of hydro-abrasive machining (HAM) could be considerably improved if the energy dissipation\\u000a phenomenon of the jet-like tool during the material removal is clearly understood. An on-line technique for quantifying the\\u000a amount of energy dissipated in the workpiece during HAM using acoustic emission (AE) measurements is presented in this paper.\\u000a The measured AE-signals are linked to

  14. Experimental investigations into forces acting during a magnetic abrasive finishing process

    Microsoft Academic Search

    Dhirendra K. Singh; V. K. Jain; V. Raghuram

    2006-01-01

    A magnetic abrasive finishing (MAF) process is the one in which material is removed in such a way that surface finishing and\\u000a deburring are performed simultaneously with the applied magnetic field in the finishing zone. Knowledge of forces acting during\\u000a MAF is important to understand the mechanism of material removal. Forces have direct influence on the generation of a finished

  15. An in-vitro investigation of the effects of variable operating parameters on alumina air-abrasion cutting characteristics.

    PubMed

    Paolinelis, George; Banerjee, Avijit; Watson, Timothy F

    2009-01-01

    Air-abrasion is a tooth preparation technology developed in the 1940s that is currently gaining popularity due to its compatibility with adhesive restorations. Variables, including propellant pressure, powder flow rate, nozzle angle and distance to the tooth surface abrasion time, can affect the cutting rate of the air-abrasion unit. A static setup and a more clinically realistic dynamic experimental setup have been used to assess the effect of these parameters of the cutting rate on an enamel analogue. By keeping each parameter fixed, its effect on the cutting rate was examined. The results showed that increasing the propellant pressure (20-100 PSI) caused an almost linear increase in the cutting rate in both setups. Increasing the powder flow rate (0.5 - 3 g/minute) concurrently increased the powder flow and caused an increase in the cutting rate but with a plateau differing for the different propellant pressures. The nozzle angles producing the highest cutting rates were 60 degrees and 75 degrees for static and dynamic cutting, respectively, with smaller and larger angles producing lower rates. Increasing abrasion time in static cutting and the nozzle advancement rate in dynamic cutting both caused an increase in the cutting rate. These findings are relevant for both clinicians, who might wish to alter the cutting rate of their instrument, and researchers, who should always control the numerous parameters in studies involving air-abrasion in order to control the variables, which can influence the end effect of air-abrasion. PMID:19192842

  16. Nuclear-chemical methods in a hard tooth tissue abrasion study

    NASA Astrophysics Data System (ADS)

    Gosman, A.; Sp?vá?ek, V.; Koní?ek, J.; Vopálka, D.; Hou?ová, D.; Doležalová, L.

    1999-01-01

    The advanced method consists in implantation—labelling of the thin surface layers of the solid objects, e.g. hard tooth tissue, by atoms of suitable natural or artificial radionuclides. Nuclides from the uranium series were implanted into the surface by using nuclear recoil effect at alpha decay of 226Ra to 222Rn, alpha decay of 222Rn to RaA, alpha decay of RaA to RaB (beta-emitter) and further alpha or beta emitters. With regard to chosen alpha detection and to the half—lives of the radionuclides, there was actually measured the activity of 222Rn, RaA and RaC’ in the thin surface layer. This was followed by the laboratory simulation of the abrasion in the system of “toothbrush—various suspensions of the tooth-pastes—hard tooth tissue (or material standard—ivory)” in specially designed device—the dentoabrasionmeter. The activities of the tissue surface measured before and after abrasion were used for calculations of the relative drop of the surface activity. On this basis the influence of various tooth-pastes containing various abrasive substances was determined.

  17. Efficacy of a new jet nozzle for removal of carious dentin with an air abrasion system.

    PubMed

    Honda, Kosuke; Kinoshita, Naoto; Abe, Tetsuya; Hasegawa, Makoto; Shimizu, Akihiko

    2008-11-01

    A new version of an air abrasion device, which expelled abrasive sodium bicarbonate powder, was fabricated to remove carious tissue. This device had a motor-driven mechanism to control the amount of powder expelled. The purpose of this study was to estimate the abrading efficacy of this device, in particular the new jet nozzle, for removal of carious dentin. Powder was supplied to the handpiece by a rotary gear attached to the powder control motor. Two types of jet nozzles, a cylinder-type and a bugle-type, were fabricated and evaluated. The duct of bugle-type nozzle had an isthmus to increase the air pressure on the powder and to spread it out in a cone-shaped flow. Results obtained showed that the bugle-type jet nozzle exhibited a more prominent abrasive capability. Compared to the cylinder-type nozzle, it was thus more effective in removing the carious dentin which remained in the undercut region of the cavities. PMID:19241693

  18. Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response.

    PubMed

    Shi, Xingling; Xu, Lingli; Munar, Melvin L; Ishikawa, Kunio

    2015-04-01

    Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant-gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl2 solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120°C was the critical temperature for the hydrothermal treatment condition. Treatment below 120°C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. PMID:25686920

  19. Drill Holes and Predation Traces versus Abrasion-Induced Artifacts Revealed by Tumbling Experiments

    PubMed Central

    Gorzelak, Przemys?aw; Salamon, Mariusz A.; Trz?siok, Dawid; Nied?wiedzki, Robert

    2013-01-01

    Drill holes made by predators in prey shells are widely considered to be the most unambiguous bodies of evidence of predator-prey interactions in the fossil record. However, recognition of traces of predatory origin from those formed by abiotic factors still waits for a rigorous evaluation as a prerequisite to ascertain predation intensity through geologic time and to test macroevolutionary patterns. New experimental data from tumbling various extant shells demonstrate that abrasion may leave holes strongly resembling the traces produced by drilling predators. They typically represent singular, circular to oval penetrations perpendicular to the shell surface. These data provide an alternative explanation to the drilling predation hypothesis for the origin of holes recorded in fossil shells. Although various non-morphological criteria (evaluation of holes for non-random distribution) and morphometric studies (quantification of the drill hole shape) have been employed to separate biological from abiotic traces, these are probably insufficient to exclude abrasion artifacts, consequently leading to overestimate predation intensity. As a result, from now on, we must adopt more rigorous criteria to appropriately distinguish abrasion artifacts from drill holes, such as microstructural identification of micro-rasping traces. PMID:23505530

  20. Fabricating superhydrophobic polymer surfaces with excellent abrasion resistance by a simple lamination templating method.

    PubMed

    Xu, Qian Feng; Mondal, Bikash; Lyons, Alan M

    2011-09-01

    Fabricating robust superhydrophobic surfaces for commercial applications is challenging as the fine-scale surface features, necessary to achieve superhydrophobicity, are susceptible to mechanical damage. Herein, we report a simple and inexpensive lamination templating method to create superhydrophobic polymer surfaces with excellent abrasion resistance and water pressure stability. To fabricate the surfaces, polyethylene films were laminated against woven wire mesh templates. After cooling, the mesh was peeled from the polymer creating a 3D array of ordered polymer microposts on the polymer surface. The resulting texture is monolithic with the polymer film and requires no chemical modification to exhibit superhydrophobicity. By controlling lamination parameters and mesh dimensions, polyethylene surfaces were fabricated that exhibit static contact angles of 160° and slip angles of 5°. Chemical and mechanical stability was evaluated using an array of manual tests as well as a standard reciprocating abraser test. Surfaces remained superhydrophobic after more than 5500 abrasion cycles at a pressure of 32.0 kPa. In addition, the surface remains dry after immersing into water for 5 h at 55 kPa. This method is environmental friendly, as it employs no solvents or harsh chemicals and may provide an economically viable path to manufacture large areas of mechanically robust superhydrophobic surfaces from inexpensive polymers and reusable templates. PMID:21797228

  1. Reducing the mechanical action of polishing pressure and abrasive during copper chemical mechanical planarization

    NASA Astrophysics Data System (ADS)

    Mengting, Jiang; Yuling, Liu

    2014-12-01

    Chemical mechanical planarization (CMP) is a critical process in deep sub-micron integrated circuit manufacturing. This study aims to improve the planarization capability of slurry, while minimizing the mechanical action of the pressure and silica abrasive. Through conducting a series of single-factor experiments, the appropriate pressure and the optimum abrasive concentration for the alkaline slurry were confirmed. However, the reduced mechanical action may bring about a decline of the polishing rate, and further resulting in the decrease of throughput. Therefore, we take an approach to compensating for the loss of mechanical action by optimizing the composition of the slurry to enhance the chemical action in the CMP process. So 0.5 wt% abrasive concentration of alkaline slurry for copper polishing was developed, it can achieve planarization efficiently and obtain a wafer surface with no corrosion defect at a reduced pressure of 1.0 psi. The results presented here will contribute to the development of a “softer gentler polishing” technique in the future.

  2. Evaluation of the Effects of Enameloplasty and Air Abrasion on Sealant Micro-Leakage

    PubMed Central

    Soleymani, Aliasghar; Bahrololoomi, Zahra; Javadinejadi, Shahrzad; Salehi, Parisa

    2014-01-01

    Objective: Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1) acid etching, 2) fissure enameloplasty and acid etching, and 3) air abrasion and acid etching. Materials and Methods: Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group). Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure. Results: Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016), but no significant difference in micro-leakage was observed between air abrasion and the other methods. Conclusion: Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too. PMID:25628693

  3. Development and Testing of Abrasion Resistant Hard Coats For Polymer Film Reflectors: Preprint

    SciTech Connect

    Jorgensen, G.; Gee, R.; DiGrazia, M.

    2010-10-01

    Reflective polymer film technology can significantly reduce the cost of solar reflectors and installed Concentrated Solar Power (CSP) plants by both reduced material cost and lower weight. One challenge of polymer reflectors in the CSP environment pertains to contact cleaning methods typically used with glass mirrors. Such contact cleaning methods can scratch the surface of polymer reflectors and thereby reduce specular reflectance. ReflecTech, Inc. (a subsidiary of SkyFuel, Inc.) and the National Renewable Energy Laboratory (NREL) initiated a cooperative research and development agreement (CRADA) to devise and develop an abrasion resistant coating (ARC) suitable for deposition onto polymer based mirror film. A number of candidate ARC products were identified as candidate formulations. Industrial collaborators prepared samples having their ARCs deposited onto ReflecTech Mirror Film pre-laminated to aluminum sheet substrates. Samples were provided for evaluation and subjected to baseline (unweathered) and accelerated exposure conditions and subsequently characterized for abrasion resistance and adhesion. An advanced ARC product has been identified that exhibits outstanding initial abrasion resistance and adhesion to ReflecTech Mirror Film. These properties were also retained after exposure to the various accelerated stress conditions. This material has been successfully manufactured as a 1.5 m wide roll-to-roll construction in a production environment.

  4. The art and science of abrasive finishing and polishing in restorative dentistry.

    PubMed

    Jefferies, S R

    1998-10-01

    Effective use of rotary cutting burs and bonded, coated, and loose abrasives can greatly simplify and improve the effectiveness of finishing and polishing procedures. Fluted carbide finishing burs appear to be the optimal rotary contouring devices for posterior composite resins. Finishing diamonds are preferred for gross finishing of adjusted porcelain. Coated abrasive discs and strips provide unique interproximal and incisal access and are preferred for finishing and polishing of microfil resins. Rubberized bonded abrasives have evolved to provide a greater range of finishing and polishing action on composite resin and for polishing porcelain. A wide selection of aluminum oxide and diamond polishing pastes, together with highly effective felt and foam application devices, are now available to polish composite and porcelain to an enamel-like appearance. Aluminum oxide composite polishing pastes are highly effective and strongly recommended for use on highly filled hybrid composites but have limited utility on microfil resins, with use of extrafine (0.3-mu) pastes clearly contraindicated. PMID:9891644

  5. Device for Underwater Laboratory Simulation of Unconfined Blast Waves

    E-print Network

    Courtney, Elijah; Courtney, Michael

    2015-01-01

    Shock tubes simulate blast waves to study their effects in air under laboratory conditions; however, few experimental models exist for simulating underwater blast waves that are needed for facilitating experiments in underwater blast transmission, determining injury thresholds in marine animals, validating numerical models, and exploring mitigation strategies for explosive well removals. This method incorporates an oxy-acetylene driven underwater blast simulator which creates peak blast pressures of about 1860 kPa. Shot-to-shot consistency was fair, with an average standard deviation near 150 kPa. Results suggest peak blast pressures from 460 kPa to 1860 kPa are available by adjusting the distance from the source.

  6. Note: Device for underwater laboratory simulation of unconfined blast waves

    NASA Astrophysics Data System (ADS)

    Courtney, Elijah; Courtney, Amy; Courtney, Michael

    2015-06-01

    Shock tubes simulate blast waves to study their effects in air under laboratory conditions; however, few experimental models exist for simulating underwater blast waves that are needed for facilitating experiments in underwater blast transmission, determining injury thresholds in marine animals, validating numerical models, and exploring mitigation strategies for explosive well removals. This method incorporates an oxy-acetylene driven underwater blast simulator which creates peak blast pressures of about 1860 kPa. Shot-to-shot consistency was fair, with an average standard deviation near 150 kPa. Results suggest that peak blast pressures from 460 kPa to 1860 kPa are available by adjusting the distance from the source.

  7. An Analytic Model of Close-Range Blast Fragment Loading

    Microsoft Academic Search

    Ernst Rottenkolber; Werner Arnold

    2005-01-01

    The effects of blast-fragmentation warheads need to be carefully characterized in a variety of applications like passive and active vehicle protection or hard target defeat and TBM defense. With these applications in mind, we have developed a collection of tools called FI-BLAST (Fast Interface for Blast-Fragment Load Analysis of Structures). In the present paper we describe the essential part of

  8. An Analytic Model of Close-Range Blast Fragment Loading

    Microsoft Academic Search

    Ernst Rottenkolber; Werner Arnold

    2006-01-01

    The effects of blast-fragmentation warheads need to be carefully characterized in a variety of applications like passive and active vehicle protection or hard target defeat and TBM defense. With these applications in mind, we have developed a collection of tools called FI-BLAST (Fast Interface for Blast-Fragment Load Analysis of Structures). In the present paper we describe the essential part of

  9. Mitigation of blast effects on aluminum foam protected masonry walls

    Microsoft Academic Search

    Yu Su; Chengqing Wu; Mike Griffith

    2008-01-01

    Terrorist attacks using improvised explosive devices (IED) can result in unreinforced masonry (URM) wall collapse. Protecting\\u000a URM wall from IED attack is very complicated. An effective solution to mitigate blast effects on URM wall is to retrofit URM\\u000a walls with metallic foam sheets to absorb blast energy. However, mitigation of blast effects on metallic foam protected URM\\u000a walls is currently

  10. A computational study on brain tissue under blast: primary and tertiary blast injuries.

    PubMed

    Rezaei, A; Salimi Jazi, M; Karami, G; Ziejewski, M

    2014-08-01

    In this paper, a biomechanical study of a human head model exposed to blast shock waves followed by a blunt impact with the surface of the enclosing walls of a confined space is carried out. Under blast, the head may experience primary blast injury (PBI) due to exposure to the shockwaves and tertiary blast injury (TeBI) due to a possible blunt impact. We examine the brain response data in a deformable finite element head model in terms of the inflicted stress/pressure, velocity, and acceleration on the brain for several blast scenarios with different intensities. The data will be compared for open space and confined spaces. Following the initial impact of the shock front in the confined space, one can see the fluctuations in biomechanical data due to wave reflections. Although the severity of the PBI and TeBI is dependent on the situation, for the cases studied here, PBI is considerably more pronounced than TeBI in confined spaces. PMID:24515869

  11. Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments

    PubMed Central

    RODRIGUES, Marcela Charantola; MONDELLI, Rafael Francisco Lia; OLIVEIRA, Gabriela Ulian; FRANCO, Eduardo Batista; BASEGGIO, Wagner; WANG, Linda

    2013-01-01

    Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. Material and Methods: Fifty (50) fragments of bovine enamel (15 mm x 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p?0.05) which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p?0.05). Results: Means and standard deviations of roughness and wear (mm) after all the promoted stages were: G1=7.26(1.81)/13.16(2.67), G2=2.02(0.62)/37.44(3.33), G3=1.81(0.91)/34.93(6.92), G4=1.92(0.29)/38.42(0.65) and G5=1.98(0.53)/33.45(2.66). At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. Conclusions: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear. PMID:23739863

  12. Rock Abrasion as Seen by the MSL Curiosity Rover: Insights on Physical Weathering on Mars

    NASA Astrophysics Data System (ADS)

    Bridges, N.; Day, M. D.; Le Mouelic, S.; Martin-Torres, F. J.; Newsom, H. E.; Sullivan, R. J., Jr.; Ullan, A.; Wiens, R. C.; Zorzano, M. P.

    2014-12-01

    Mars is a dry planet, with actively blowing sand in many regions. In the absence of stable liquid water and an active hydrosphere, rates of chemical weathering are slow, such that aeolian abrasion is a dominant agent of landscape modification where sand is present and winds above threshold occur at sufficient frequency. Reflecting this activity, ventifacts, rocks that have been abraded by windborne particles, and wind-eroded outcrops, are common. They provide invaluable markers of the Martian wind record and insight into climate and landscape modification. Ventifacts are distributed along the traverse of the Mars Science Laboratory Curiosity rover. They contain one or more diagnostic features and textures: Facets, keels, basal sills, elongated pits, scallops/flutes, grooves, rock tails, and lineations. Keels at the junction of facets are sharp enough to pose a hazard MSL's wheels in some areas. Geomorphic and textural patterns on outcrops indicate retreat of windward faces. Moonlight Valley and other depressions are demarcated by undercut walls and scree boulders, with the valley interiors containing fewer rocks, most of which show evidence for significant abrasion. Together, this suggests widening and undercutting of the valley walls, and erosion of interior rocks, by windblown sand. HiRISE images do not show any dark sand dunes in the traverse so far, in contrast to the large dune field to the south that is migrating up to 2 m per year. In addition, ChemCam shows that the rock Bathurst has a rind rich in mobile elements that would be removed in an abrading environment. This indicates that rock abrasion was likely more dominant in the past, a hypothesis consistent with rapid scarp retreat as suggested by the cosmogenic noble gases in Yellowknife Bay. Ventifacts and evidence for bedrock abrasion have also been found at the Pathfinder, Spirit, and Opportunity sites, areas, like the Curiosity traverse so far, that lack evidence for current high sand fluxes. Yardangs are also common on the planet, regardless of whether local sand is mobile. This suggest that abrasion on Mars is an episodic process driven by the passage of sand in which rock retreat rates, based on fluxes of current active dunes, may reach 10s of microns per year. Such a process has acted, over long time scales, to imprint upon the surface a record of sand activity.

  13. Using vibration prediction to reduce blasting costs and complaints

    SciTech Connect

    Berger, P.R. Jr. [GeoSonics Inc., Warrendale, PA (United States); Leonard, T. [Bardon Trimount, Inc., Peabody, MA (United States). Aggregates Div.; Papillon, B.E. [Austin Powder Co., Northampton, PA (United States)

    1996-12-31

    Bardon Trimount Inc., a large producer of aggregate, crushed stone, and concrete, was experiencing significant public opposition to its five quarries in the Boston area. It was believed by the authors that this opposition could be significantly lessened if the total number of blasts per week were reduced. Although the blasting company at these quarries, Austin Powder Company, contended that this could easily and safely be accomplished by increasing the size of the blasts, regulations precluded this alternative by limiting the total amount of explosives that could be used per blast. In an attempt to resolve this impasse, Iso-Seismic Studies were performed. The results of these studies clearly illustrated how the surface geology surrounding these quarries affected ground vibrations as they emanated from a blast site. The results of these studies were presented to the public which resulted in greater confidence that larger blasts could be safely controlled. Moreover, local regulators were similarly impressed with the results and were persuaded to waive their limits on blast size. The aftermath of these studies has been a dramatic decrease in drilling and blasting costs, a sharp drop in blasting complaints, and a much improved relationship between Bardon Trimount and the surrounding communities.

  14. Offutt Air Force Base, Looking Glass Airborne Command Post, Blast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Offutt Air Force Base, Looking Glass Airborne Command Post, Blast Deflector Fences, Northeast & Southwest sides of Operational Apron, Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  15. On the Interaction and Coalescence if Spherical Blast Waves

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Freeman, Robert J.

    2005-01-01

    The scaling and similarity laws concerning the propagation of isolated spherical blast waves are briefly reviewed. Both point source explosions and high pressure gas explosions are considered. Test data on blast overpressure from the interaction and coalescence of spherical blast waves emanating from explosives in the form of shaped charges of different strength placed in the vicinity of a solid propellant stack are presented. These data are discussed with regard to the scaling laws concerning the decay of blast overpressure. The results point out the possibility of detecting source explosions from far-field pressure measurements.

  16. Mechanisms of Hearing Loss after Blast Injury to the Ear

    PubMed Central

    Cho, Sung-Il; Gao, Simon S.; Xia, Anping; Wang, Rosalie; Salles, Felipe T.; Raphael, Patrick D.; Abaya, Homer; Wachtel, Jacqueline; Baek, Jongmin; Jacobs, David; Rasband, Matthew N.; Oghalai, John S.

    2013-01-01

    Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body’s most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction. PMID:23840874

  17. Indoor human response to blast sounds that generate rattles.

    PubMed

    Schomer, P D; Averbuch, A

    1989-08-01

    The two major noise sources that cause environmental problems for the U. S. Army are helicopters and large weapons such as artillery, tanks, and demolition. These large weapons produce blast sounds that contain little energy above 200 Hz and that are particularly troublesome to deal with because they excite rattles in structures. The purpose of this study was to systematically test subjective response to the presence or absence of rattles in otherwise similar blast sound environments. A second purpose of the study was to test if there were structural changes that could reduce annoyance within the indoor blast sound environment. This study was done using a specially constructed test house and highly repeatable shake table to generate the blast sounds. The data clearly show that no commonly used environmental noise measure adequately describes the indoor environment when the blast excites rattles. Although the indoor blast ASEL changes by only about a decibel or so (and the indoor blast CSEL changes by even less), the subjective response changes by up to 13 dB. At low blast levels, the increase in human annoyance response is largest, and this annoyance response offset decreases to about 6 dB when the outside, flat-weighted peak sound-pressure level of the blast increases from 112 to 122 dB. PMID:2768676

  18. 13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH SAWDUST HOPPER. BLASTING TUB HAS DOUBLE WALLS OF 3/4' THICK STEEL ARMOR PLATE. CHARGE TO BE TESTED IS BURIED IN SAWDUST WITH FLAME RESISTANT CHEMICALS. ELEVATOR BEHIND TUB CARRIES SAWDUST BACK TO TOP OF SAWDUST HOPPER AFTER TEST IS COMPLETED AND SAWDUST IN BLASTING TUB HAS BEEN SIFTED FOR SHELL FRAGMENTS. LOUVERS IN WALLS ARE HINGED FREELY SO THEY OPEN TO RELIEVE BLAST PRESSURE DURING A TEST. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

  19. Brain injury from explosive blast: description and clinical management.

    PubMed

    Ling, G; Ecklund, J M; Bandak, F A

    2015-01-01

    Accumulating clinical experience is indicating that explosive blast brain injury is becoming recognized as a disease distinct from the penetrating form of blast injury as well as the classic closed head injury (CHI). In recent US conflicts in Iraq and Afghanistan, over 60% of combat casualties were from explosive blast with the hallmark explosive weapon being the improvised explosive device (IED). Explosive blast TBI is a condition afflicting many combat injured warfighters potentially constituting another category of TBI. Clinically, it shares many features with conventional TBI but possesses some unique aspects. In its mild form, it also shares many clinical features with PTSD but here again has distinct aspects. Although military medical providers depend on civilian standard of care guidelines when managing explosive blast mTBI, they are continually adapting their medical practice in order to optimize the treatment of this disease, particularly in a theater of war. It is clear that further rigorous scientific study of explosive blast mTBI at both the basic science and clinical levels is needed. This research must include improved understanding of the causes and mechanisms of explosive blast TBI as well as comprehensive epidemiologic studies to determine the prevalence of this disease and its risk factors. A widely accepted unambiguous clinical description of explosive blast mTBI with diagnostic criteria would greatly improve diagnosis. It is hoped that through appropriate research meaningful prevention, mitigation, and treatment strategies for explosive blast mTBI can be speedily realized. PMID:25702216

  20. Understanding litter decomposition in drylands: Is litter abrasion an important abiotic factor?

    NASA Astrophysics Data System (ADS)

    Peterson, M.; Bravo-Garza, M. R.; Throop, H. L.; Duarte, L. C.

    2012-12-01

    Drylands comprise approximately 40% of global land cover and about 20% of global soil organic carbon (C) pool. Changes in dryland ecosystem processes, such as litter decomposition, could greatly influence global C cycling and climate change. Current models underestimate rates of litter decomposition in drylands, and little is known about the role and interactions of abiotic drivers in these systems. Research suggests leaf abrasion may play an important role on litter decomposition in drylands by increasing microbial activity or leaching. The Scrape Site at Jornada LTER was stripped of vegetation in 1991, leaving exposed soil that could serve as a source of sand particles to promote leaf abrasion on mesquite shrubs located downwind. This project examines the role that leaf abrasion, promoted in the field by wind erosion, and induced through laboratory simulations, will play in litter decomposition. We hypothesize that leaf abrasion will increase rates of litter decomposition due to facilitation of microbial colonization. Mesquite leaves were collected from two locations: down-wind from the Scrape Site and 80 meters away representing "field abraded" and "unabraded" treatments, respectively. For a "lab abraded" treatment, abrasion was performed by shaking leaves for 30 seconds with sand particles to simulate microscopic characteristics seen in "field abraded" treatment; this treatment resulted in an average leaf area loss of 3.267 %. Differences in decomposition rates among litter treatments were evaluated in a 16 week laboratory incubation. Litter was incubated at 22°C in airtight glass jars containing 50 g of soil (0.053 g water g-1 soil). Rapid colonization by fungi was apparent across treatments, but lab abraded litter showed the most abundant growth. Consequently, lab abraded litter treatment showed 20% and 30% times more accumulation of CO2 -C than field (P= 0.0008) and unabraded (P< 0.0001) litter treatments during the first 6 days of incubation. These results agree with a significant higher mass loss of lab abraded litter after one week of incubation, 4.6% and 4.8% higher than field abraded (P= 0.0005) and unabraded (P= 0.0004) litter, respectively. Results from litter mass loss showed an exponential decrease in all treatments during the first 4 weeks of incubation, where abraded treatments had higher decomposition decay constants than the unabraded leaves: 0.187, 0.170, and 0.164 for the lab abraded, field abraded and unabraded treatments, respectively. Interestingly, differences in the process of litter decomposition among treatments were pronounced during the first weeks of incubation and disappeared by the end of the incubation period where a similar rate of litter mineralization and a ca. 50% mass loss was reported by all litter treatments. Our results suggest that abrasion of leaf litter enhances early stages of decomposition perhaps by creating an exposed outer tissue suitable for microbial colonization. This is reflected by a higher initial accumulation of CO2-C and losses of litter mass in lab abraded litter. Influence of abrasion in litter decomposition was more evident on lab abraded leaves perhaps due to the faster and easier microbial colonization of recently abraded surfaces. Work is in progress to evaluate the amount of C transferred to the soil and the implications of our results on longer-term decomposition.

  1. Cylindrical blast wave propagation in an enclosure

    NASA Astrophysics Data System (ADS)

    Bagabir, A. M.

    2012-11-01

    A numerical study of propagation and interaction of cylindrical blast waves in an enclosure at different blast intensities is presented. The interest to study such flows stems from the need to bring in an updated description of the flow field and to predict the pressure loads on the structure. An implicit-unfactored high-resolution hybrid Riemann solver for the two-dimensional Euler equations is used. The characteristic values at the cell faces are evaluated by a modified MUSCL scheme. Numerical schlieren-type images are used for understanding the flows qualitatively. The investigation indicated that the resulting flow field is dominated by complex interacting shock systems due to the complex series of shock focusing events, shock-structure and shock-shock interactions. The pressure-load distribution and maximum overpressure are estimated.

  2. Shock (Blast) Mitigation by "Soft" Condensed Matter

    E-print Network

    Vitali F. Nesterenko

    2007-08-24

    It is a common point that "soft" condensed matter (like granular materials or foams) can reduce damage caused by impact or explosion. It is attributed to their ability to absorb significant energy. This is certainly the case for a quasistatic type of deformation at low velocity of impact where such materials are widely used for packing of fragile devices. At the same time a mitigation of blast phenomena must take into account shock wave properties of "soft" matter which very often exhibit highly nonlinear, highly heterogeneous and dissipative behavior. This paper considers applications of "soft" condensed matter for blast mitigation using simplified approach, presents analysis of some anomalous effects and suggestions for future research in this exciting area.

  3. Blast waves generated by planar detonations

    NASA Astrophysics Data System (ADS)

    Thibault, P. A.; Penrose, J. D.; Shepherd, J. E.; Benedick, W. B.; Ritzel, D. V.

    This paper presents experimental and theoretical studies of blast waves generated by gaseous and HE detonations in long cylindrical tubes. The experimental studies were performed using the 1.8 m diameter shock tube facilities at the Defence Research Establishment Suffield and at the New Mexico Engineering Research Institute. Two gaseous explosives, acetylene-oxygen and hydrogen-air, and one solid explosive, 120g nitroguanidine, were used in order to verify the validity of energy scaling in the far-field. The above experimental work is supported by one- and two-dimensional numerical computations which are based on the Flux Corrected Transport (FCT) algorithm. The experimental results are also analyzed in terms of a simple analytical blast model.

  4. WIPFRAG -- A new tool for blast evaluation

    SciTech Connect

    Palangio, T.C. [ETI Explosives, North Bay, Ontario (Canada)

    1995-12-31

    Traditionally, mines and quarries have lacked a practical method of describing blast results. Adjectives such as good, fair, or poor do little to define performance, and sieving and/or counting particles was too costly and time consuming to be considered a viable alternative. Recent advances in imaging technology along with ongoing research and development by Franklin Geotechnical Ltd., ETI Explosives, INCO and the University of Waterloo have created a digital analysis system that generates a fragmentation size distribution curve from muckpile images. These images are acquired on a videotape or still photo format and can be automatically processed by grabbing the image, scaling it and defining the block edges through a series of routines to quantify blast fragmentation. This technique is ideal for evaluating oversize reduction programs, pattern optimization efforts, prevention of overblasting and fines generation or just benchmarking. This paper will describe the WIPFRAG System and illustrate by means of actual case studies, the usefulness of this tool.

  5. Metal sorption on blast-furnace slag

    Microsoft Academic Search

    S. V. Dimitrova

    1996-01-01

    The removal of Cu, Ni and Zn-ions from water solution by ungranulated blast-furnace slag has been studied depending on contact time, initial ion concentration, pH and solution temperature. The polymineral composition and the slag specific properties determine its high sorption activity in metal salts solutions. In the range of the concentrations studied (10?4–10?3 M), the sorption data for Cu2+, Ni2+

  6. Developments in vapour cloud explosion blast modeling.

    PubMed

    Mercx, W P; van den Berg, A C; Hayhurst, C J; Robertson, N J; Moran, K C

    2000-01-01

    TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be used as a simple and practical method. Computer codes based on computational fluid dynamics (CFD) like AutoReaGas, developed by TNO and Century Dynamics, could be used also in case a more rigorous analysis is required. Application of the Multi-Energy method requires knowledge of two parameters describing the explosion: a charge size and a charge strength. During the last years, research has led to an improved determination of the charge strength (i.e., the class number or source overpressure) to be chosen to apply the blast charts. A correlation has been derived relating the charge strength to a set of parameters describing the boundary conditions of the flammable cloud and the fuel in the cloud. A simple approach may not be satisfactory in all situations. The overpressure distribution inside a vapour cloud explosion is generally not homogeneous and the presence of obstructions causes directional blast propagation in the near field. A CFD approach, in which the actual situation is modeled, supplies case-specific results. An overview of the key aspects relevant to the application of the Multi-Energy method and CFD modeling is provided. Then the application of the two methods is demonstrated for an example problem involving the calculation of the explosion blast load on a structure at some distance from the explosion in an offshore platform complex. PMID:10677667

  7. Blast furnace on-line simulation model

    Microsoft Academic Search

    Henrik Saxén

    1990-01-01

    A mathematical model of the ironmaking blast furnace (BF) is presented. The model describes the steady-state operation of\\u000a the furnace in one spatial dimension using real process data sampled at the steelworks. The measurement data are reconciled\\u000a by an interface routine which yields boundary conditions obeying the conservation laws of atoms and energy. The simulation\\u000a model, which provides a picture

  8. Centrifugal shot blasting. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-07-01

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

  9. Coke oven gas injection to blast furnaces

    SciTech Connect

    Maddalena, F.L.; Terza, R.R.; Sobek, T.F.; Myklebust, K.L. [U.S. Steel, Clairton, PA (United States)

    1995-12-01

    U.S. Steel has three major facilities remaining in Pennsylvania`s Mon Valley near Pittsburgh. The Clairton Coke Works operates 12 batteries which produce 4.7 million tons of coke annually. The Edgar Thomson Works in Braddock is a 2.7 million ton per year steel plant. Irvin Works in Dravosburg has a hot strip mill and a range of finishing facilities. The coke works produces 120 mmscfd of coke oven gas in excess of the battery heating requirements. This surplus gas is used primarily in steel re-heating furnaces and for boiler fuel to produce steam for plant use. In conjunction with blast furnace gas, it is also used for power generation of up to 90 MW. However, matching the consumption with the production of gas has proved to be difficult. Consequently, surplus gas has been flared at rates of up to 50 mmscfd, totaling 400 mmscf in several months. By 1993, several changes in key conditions provided the impetus to install equipment to inject coke oven gas into the blast furnaces. This paper describes the planning and implementation of a project to replace natural gas in the furnaces with coke oven gas. It involved replacement of 7 miles of pipeline between the coking plants and the blast furnaces, equipment capable of compressing coke oven gas from 10 to 50 psig, and installation of electrical and control systems to deliver gas as demanded.

  10. Vehicle overturning vulnerability from air blast loads

    NASA Astrophysics Data System (ADS)

    Robinson, R. R.; Napadensky, H.; Longinow, A.

    1984-08-01

    The overturning response of an armored personnel carrier to air blast loads derived from a nuclear blast environment is presented. The orientation of the vehicle is side-on to the air blast shock front. It is assumed there is no translation at the downwind wheels, i.e., the roll over point. In addition, the vehicle is assumed to behave as a rigid body. That is, the suspension system are taken as rigid, so that the wheels and axles rotate in unison with the body. It can be shown that this assumption slightly overestimates the overturning resistance of vehicles with suspension systems. For a stiff suspension system, such as that of the APC, the rigid body behavior assumption is justified. The only motion possible for this analysis is rotation about the rollover point. The effect of overturning restraint systems has been included in the analysis by incorporating a perfectly plastic vehicle to ground connection on the upwind side of the vehicle. The results give the threshold nuclear environment that just causes overturning. The threshold environment is given in terms of a peak overpressure corresponding to a weapon yield. Results are presented for a range of weapon yields from 1KT to 1MT.

  11. Mycobacterium ulcerans Fails to Infect through Skin Abrasions in a Guinea Pig Infection Model: Implications for Transmission

    PubMed Central

    Williamson, Heather R.; Mosi, Lydia; Donnell, Robert; Aqqad, Maha; Merritt, Richard W.; Small, Pamela L. C.

    2014-01-01

    Transmission of M. ulcerans, the etiological agent of Buruli ulcer, from the environment to humans remains an enigma despite decades of research. Major transmission hypotheses propose 1) that M. ulcerans is acquired through an insect bite or 2) that bacteria enter an existing wound through exposure to a contaminated environment. In studies reported here, a guinea pig infection model was developed to determine whether Buruli ulcer could be produced through passive inoculation of M. ulcerans onto a superficial abrasion. The choice of an abrasion model was based on the fact that most bacterial pathogens infecting the skin are able to infect an open lesion, and that abrasions are extremely common in children. Our studies show that after a 90d infection period, an ulcer was present at intra-dermal injection sites of all seven animals infected, whereas topical application of M. ulcerans failed to establish an infection. Mycobacterium ulcerans was cultured from all injection sites whereas infected abrasion sites healed and were culture negative. A 14d experiment was conducted to determine how long organisms persisted after inoculation. Mycobacterium ulcerans was isolated from abrasions at one hour and 24 hours post infection, but cultures from later time points were negative. Abrasion sites were qPCR positive up to seven days post infection, but negative at later timepoints. In contrast, M. ulcerans DNA was detected at intra-dermal injection sites throughout the study. M. ulcerans was cultured from injection sites at each time point. These results suggest that injection of M. ulcerans into the skin greatly facilitates infection and lends support for the role of an invertebrate vector or other route of entry such as a puncture wound or deep laceration where bacteria would be contained within the lesion. Infection through passive inoculation into an existing abrasion appears a less likely route of entry. PMID:24722416

  12. Using stream sediment lithology to explore the roles of abrasion and channel network structure in shaping downstream sediment yields

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Smith, M. E.; Pitlick, J.

    2012-12-01

    Both the flux and characteristics of stream sediment evolve downstream in response to variations in sediment supply, abrasion rate, and channel network structure. We use a simple erosion-abrasion mass balance to model the downstream evolution of sediment flux in two adjacent watersheds draining differing mixtures of soft and resistant rock types in the northern Rocky Mountains. Measurements of bed sediment grain size and lithology are used in conjunction with measured bed load and suspended load sediment fluxes to constrain the model. The results show that the downstream evolution in bed load flux and composition can be strongly influenced by subtle differences in underlying geology, which shapes both the abrasion characteristics and travel path lengths of individual rock types. In the Big Wood basin, abrasion rapidly reduces the size of soft sedimentary and volcanic rocks exposed in headwater areas, concentrating resistant granitic rocks in the stream bed and depressing bed load in favor of suspended load. Alternatively, in the North Fork Big Lost basin, volcanic and sedimentary lithologies are exposed throughout the catchment, and the bed material becomes dominated by erodible but resistant quartzitic sandstones. The result is a much higher bed load flux best modeled with modest abrasion rates. In both cases, the best-fit model can reproduce within 5% the composition of the stream bed substrate using realistic erosion and abrasion parameters. The results also demonstrate a strong linkage between modern hillslopes and channel systems even in these formerly glaciated landscapes, as the sediment signature of the primary streams reflects the systematic tapping of distinct source areas. While this work shows promise, measurement of the spatial patterns in the size and composition of bed and suspended load fluxes at locations throughout a channel network would better elucidate that relative importance of supply, sorting, and abrasion processes.

  13. Pilot-scale treatability testing -- Recycle, reuse, and disposal of materials from decontamination and decommissioning activities: Soda blasting demonstration

    SciTech Connect

    NONE

    1995-08-01

    The US Department of Energy (DOE) is in the process of defining the nature and magnitude of decontamination and decommissioning (D and D) obligations at its sites. With disposal costs rising and available storage facilities decreasing, DOE is exploring and implementing new waste minimizing D and D techniques. Technology demonstrations are being conducted by LMES at a DOE gaseous diffusion processing plant, the K-25 Site, in Oak Ridge, Tennessee. The gaseous diffusion process employed at Oak Ridge separated uranium-235 from uranium ore for use in atomic weapons and commercial reactors. These activities contaminated concrete and other surfaces within the plant with uranium, technetium, and other constituents. The objective of current K-25 D and D research is to make available cost-effective and energy-efficient techniques to advance remediation and waste management methods at the K-25 Site and other DOE sites. To support this objective, O`Brien and Gere tested a decontamination system on K-25 Site concrete and steel surfaces contaminated with radioactive and hazardous waste. A scouring system has been developed that removes fixed hazardous and radioactive surface contamination and minimizes residual waste. This system utilizes an abrasive sodium bicarbonate medium that is projected at contaminated surfaces. It mechanically removes surface contamination while leaving the surface intact. Blasting residuals are captured and dissolved in water and treated using physical/chemical processes. Pilot-scale testing of this soda blasting system and bench and pilot-scale treatment of the generated residuals were conducted from December 1993 to September 1994.

  14. Identification of rice blast resistance genes using international monogenic differentials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating diseases of rice that severely affects crop production in Jilin Province, Northeast China, where temperate japonica rice is primarily grown. In the present study, 44 representative local blast isolat...

  15. Preliminary assessment of sandwich plates subject to blast loads

    Microsoft Academic Search

    Zhenyu Xue; John W. Hutchinson

    2003-01-01

    The question motivating the present study is whether metal sandwich plates with sufficiently strong cores are able to sustain substantially larger blast loads than monolithic solid plates of the same material and total mass. Circular plates clamped at their edges are considered under blast loads large enough to produce substantial deflections. The material is elastic–perfectly plastic. Material strain-rate dependence and

  16. Investigation of Ultrafast Laser-Driven Radiative Blast Waves

    Microsoft Academic Search

    M. J. Edwards; A. J. MacKinnon; J. Zweiback; K. Shigemori; D. Ryutov; A. M. Rubenchik; K. A. Keilty; E. Liang; B. A. Remington; T. Ditmire

    2001-01-01

    We have examined the evolution of cylindrically symmetric blast waves produced by the deposition of femtosecond laser pulses in gas jets. In high- Z gases radiative effects become important. We observe the production of an ionization precursor ahead of the shock front and deceleration parameters below the adiabatic value of 1\\/2 (for a cylinder), an effect expected when the blast

  17. Blast response comparison of multiple steel frame connections

    Microsoft Academic Search

    Girum S. Urgessa; Tomasz Arciszewski

    2011-01-01

    When a structural steel frame is subjected to blast, the beam-to-column connections, which are responsible for load transfer between different members within the frame, play a major role in structural response. This paper presents results of a comparative finite element analysis of a steel frame subjected to a blast loading from a vehicular threat. The study compared three connection systems

  18. Removal of phosphate from aqueous solution with blast furnace slag

    Microsoft Academic Search

    Ensar Oguz

    2004-01-01

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential

  19. Storage stability of flour-blasted brown rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brown rice was blasted with rice flour rather than sand in a sand blaster to make microscopic nicks and cuts so that water can easily penetrate into the brown rice endosperm and cook the rice in a shorter time. The flour-blasted American Basmati brown rice, long grain brown rice, and parboiled long...

  20. VIEW FROM THE SOUTH OF THE #2 BLAST FURNACE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM THE SOUTH OF THE #2 BLAST FURNACE AND CASTING SEED ON THE LEFT, THE #1 BLAST FURNACE AND CASTING SHED ON THE RIGHT, AND THE STOVES, BOILERS, AND AUXILIARY EQUIPMENT IN THE CENTER. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  1. Identification of major blast resistance genes in the southern US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance (R) genes in rice play important roles in preventing infections of rice blast fungus, Magnaporthe oryzae. In order to identify more R genes for different rice growing areas in the Southern US, an extensive field survey of the blast fungus was performed from 2012 to 2013. A total of 500 is...

  2. Current advances on genetic resistance to rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by the fungal pathogen Magnaporthe oryzae is one of the most threatening fungal diseases resulting in significant annual crop losses worldwide. Blast disease has been effectively managed by a combination of resistant (R) gene deployment, application of fungicides, and suita...

  3. Mechanical etching of micro pockets by powder blasting

    Microsoft Academic Search

    D. S. Park; T. I. Seo; M. W. Cho

    2005-01-01

    The main objective of this research is to develop a mechanical etching technique to produce micro mould dies having micro pockets of hundreds of µm. A powder blasting technique is applied to stainless steel plates based on predefined process conditions. This paper describes the performance of a powder blasting technique and the effect of the number of nozzle scanning times

  4. Blast venting through blanket material in the HYLIFE ICF reactor

    Microsoft Academic Search

    J. C. Liu; P. F. Peterson; V. E. Schrock

    1992-01-01

    This work presents a numerical study of blast venting through various blanket configurations in the HYLIFE ICF reactor design. The study uses TSUNAMI -- a multi-dimensional, high-resolution, shock capturing code -- to predict the momentum exchange and gas dynamics for blast venting in complex geometries. In addition, the study presents conservative predictions of wall loading by gas shock and impulse

  5. Blast-furnace performance with coal-dust injection

    SciTech Connect

    G.G. Vasyura [OAO Alchevskii Metallurgicheskii Kombinat, Alchevsk (Russian Federation)

    2007-07-01

    For the blast furnace shop at OAO Alchevskii Metallurgicheskii Kombinat (AMK) the injection of pulverized fuel is promising. Preliminary steps toward its introduction are underway, including analytical research. In this context, blast furnace performance when using pulverized coal is calculated in this study.

  6. Minerals and iron-making reactions in blast furnaces

    Microsoft Academic Search

    S. Gupta; R. Sakurovs; M. Grigore; H. Sun; T. Cham; T. Hilding; M. Hallin; B. Lindblom; V. Sahajwalla

    2008-01-01

    Coke is central to blast furnace operation, but because it is the most expensive raw material used, there is continuing pressure to minimize its use. Consequently, it has become increasingly pertinent to measure and predict the factors affecting coke performance more accurately. Coke performance is affected both by its properties and blast furnace operation. Recently, the importance of the minerals

  7. Air blast atomization using large air flow rates

    Microsoft Academic Search

    G. E. Andrews

    1989-01-01

    The 'jet mix' type interacting shear layer mixing flame stabilizer has been experimentally tested to ascertain combined air blast atomization and fuel\\/air mixing characteristics at gas turbine primary zone design conditions. Air blast atomization performance improves with increasing proportion of combustion airflow use for this purpose. Low Sauter mean diameter (SMD) values were achieved, but the atomization distribution deteriorated with

  8. Experimental Studies of Mitigation Materials for Blast Induced Tbi

    NASA Astrophysics Data System (ADS)

    Alley, M. D.; Son, S. F.; Christou, G.; Goel, R.; Young, L.

    2009-12-01

    The objective of this experimental study is to compare the effects of various materials obstructing the flow of a blast wave and the ability of the material to reduce the damage caused by the blast. Several methods of energy transfer in blast wave flows are expected including: material interfaces with impedance mismatches, density changes in a given material, internal shearing, and particle fracture. Our hypothesis is that the greatest energy transfer within the obstructing material will yield the greatest mitigation effects to the blast. Sample configurations of foam were varied to introduce material interfaces and filler materials with varying densities and impedances (liquids and powders). The samples were dynamically loaded using a small scale blast produced by an explosive driven shock tube housing gram-scale explosive charges. The transmitted blast profiles were analyzed for variations in impulse characteristics and frequency components as compared to standard free field profiles. The results showed a rounding effect of the transmitted blast profile for all samples with the effects of the high density fillers surpassing all others tested. These results lead to a conclusion that low porosity, high density materials offer superior attenuation by reducing air blast features and spatially distributing the transmitted wave.

  9. Elastic–plastic response spectra for exponential blast loading

    Microsoft Academic Search

    Charis J. Gantes; Nikos G. Pnevmatikos

    2004-01-01

    The design of structures subjected to loads due to explosions is often treated by means of elastic–plastic response spectra. Such spectra that are currently available in the literature were computed on the basis of triangular shape of blast pressure with respect to time. In the present paper, response spectra based on an exponential distribution of blast pressure, which is in

  10. The spectrum of pediatric injuries after a bomb blast

    Microsoft Academic Search

    Doris A Quintana; Fred B Jordan; David W Tuggle; P. Cameron Mantor; William P Tunell

    1997-01-01

    The spectrum of pediatric injuries seen after a bomb blast is poorly documented. The pathophysiology of blast injuries differ significantly from other forms of trauma and typically result in large numbers of distinctly patterned injuries. On April 19, 1995, a truck bomb was detonated directly adjacent to the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma. A total of

  11. Standardization of a Volumetric Displacement Measurement for Two-Body Abrasion Scratch Test Data Analysis

    NASA Technical Reports Server (NTRS)

    Street, K. W. Jr.; Kobrick, R. L.; Klaus, D. M.

    2011-01-01

    A limitation has been identified in the existing test standards used for making controlled, two-body abrasion scratch measurements based solely on the width of the resultant score on the surface of the material. A new, more robust method is proposed for analyzing a surface scratch that takes into account the full three-dimensional profile of the displaced material. To accomplish this, a set of four volume- displacement metrics was systematically defined by normalizing the overall surface profile to denote statistically the area of relevance, termed the Zone of Interaction. From this baseline, depth of the trough and height of the plowed material are factored into the overall deformation assessment. Proof-of-concept data were collected and analyzed to demonstrate the performance of this proposed methodology. This technique takes advantage of advanced imaging capabilities that allow resolution of the scratched surface to be quantified in greater detail than was previously achievable. When reviewing existing data analysis techniques for conducting two-body abrasive scratch tests, it was found that the ASTM International Standard G 171 specified a generic metric based only on visually determined scratch width as a way to compare abraded materials. A limitation to this method was identified in that the scratch width is based on optical surface measurements, manually defined by approximating the boundaries, but does not consider the three-dimensional volume of material that was displaced. With large, potentially irregular deformations occurring on softer materials, it becomes unclear where to systematically determine the scratch width. Specifically, surface scratches on different samples may look the same from a top view, resulting in an identical scratch width measurement, but may vary in actual penetration depth and/or plowing deformation. Therefore, two different scratch profiles would be measured as having identical abrasion properties, although they differ significantly.

  12. Simplified Abrasion Test Methodology for Candidate EVA Glove Lay-Ups

    NASA Technical Reports Server (NTRS)

    Rabel, Emily; Aitchison, Lindsay

    2015-01-01

    During the Apollo Program, space suit outer-layer fabrics were badly abraded after performing just a few extravehicular activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots that penetrated the outer-layer fabric into the thermal protection layers after less than 8 hrs of surface operations. Current plans for the exploration planetary space suits require the space suits to support hundreds of hours of EVA on a lunar or Martian surface, creating a challenge for space suit designers to utilize materials advances made over the last 40 years and improve on the space suit fabrics used in the Apollo Program. Over the past 25 years the NASA Johnson Space Center Crew and Thermal Systems Division has focused on tumble testing as means of simulating wear on the outer layer of the space suit fabric. Most recently, in 2009, testing was performed on 4 different candidate outer layers to gather baseline data for future use in design of planetary space suit outer layers. In support of the High Performance EVA Glove Element of the Next Generation Life Support Project, testing a new configuration was recently attempted in which require 10% of the fabric per replicate of that need in 2009. The smaller fabric samples allowed for reduced per sample cost and flexibility to test small samples from manufacturers without the overhead to have a production run completed. Data collected from this iteration was compared to that taken in 2009 to validate the new test method. In addition the method also evaluated the fabrics and fabric layups used in a prototype thermal micrometeoroid garment (TMG) developed for EVA gloves under the NASA High Performance EVA Glove Project. This paper provides a review of previous abrasion studies on space suit fabrics, details methodologies used for abrasion testing in this particular study, results of the validation study, and results of the TMG testing.

  13. Microleakage on Class V glass ionomer restorations after cavity preparation with aluminum oxide air abrasion.

    PubMed

    Corona, Silmara Aparecida Milori; Borsatto, Maria Cristina; Rocha, Renata Andréa Salvitti de Sá; Palma-Dibb, Regina Guenka

    2005-01-01

    This in vitro study assessed the marginal microleakage on class V cavities prepared with aluminum oxide air abrasion and restored with different glass ionomer cements. The cavities were prepared on the buccal and lingual surfaces of 15 sound third molars with an air- abrasion device (Kreativ Mach 4.1; New Image) using a 27.5-microm aluminum oxide particle stream, and were assigned to 3 groups of 10 cavities each. The restorative materials were: group I, a conventional glass ionomer cement (Ketac-Fil); groups II and III, resin-modified glass ionomer cements (Vitremer R and Fuji II LC, respectively). After placement of the restorations, the teeth were stored in distilled water at 37 degrees C for 24 h, polished and then submitted to a thermocycling regimen of 500 cycles, isolated, immersed in 0.2% Rhodamine B solution for 24 h, included and serially sectioned. Microleakage was assessed by viewing the specimens under an optical microscope connected to a color video camera and a computer. The images obtained were digitized and analyzed for microleakage using software that allows for a standard quantitative assessment of dye penetration in millimeters. Statistical analysis was done using the Kruskall-Wallis and Wilcoxon tests. Means of dye penetration (%) were: occlusal - I: 25.76 +/- 34.35, II: 20.00 +/- 42.16, III: 28.25 +/- 41.67; cervical - I: 23.72 +/- 41.84; II: 44.22 +/- 49.69, III: 39.27 +/- 50.74. No statistically significant differences (p>0.05) were observed among either the glass ionomer cements or the margins. In conclusion, class V cavities restored with either conventional or resin-modified glass ionomer cements after preparation with aluminum oxide air abrasion did not show complete sealing at the enamel and dentin/cementum margins. PMID:16113931

  14. The influence of aluminum and carbon on the abrasion resistance of high manganese steels

    NASA Astrophysics Data System (ADS)

    Buckholz, Samuel August

    Abrasive wear testing of lightweight, austenitic Fe-Mn-Al-C cast steel has been performed in accordance with ASTM G65 using a dry sand, rubber wheel, abrasion testing apparatus. Testing was conducted on a series of Fe-30Mn-XAl-YC-1Si-0.5Mo chemistries containing aluminum levels from 2.9 to 9.5 wt.% and carbon levels from 0.9 to 1.83 wt.%. Solution treated materials having an austenitic microstructure produced the highest wear resistance. Wear resistance decreased with higher aluminum, lower carbon, and higher hardness after age hardening. In the solution treated condition the wear rate was a strong function of the aluminum to carbon ratio and the wear rate increased with a parabolic dependence on the Al/C ratio, which ranged from 1.8 to 10.2. Examination of the surface wear scar revealed a mechanism of plowing during abrasion testing and this method of material removal is sensitive to work hardening rate. Work hardening behavior was determined from tensile tests and also decreased with increasing Al/C ratio and after aging hardening. The loss of wear resistance is related to short range ordering of Al and C in the solution treated materials and kappa-carbide precipitation in age hardened materials and both contribute to planar slip and lower work hardening rates. A high carbon tool steel (W1) and a bainitic low alloy steel (SAE 8620) were also tested for comparison. A lightweight steel containing 6.5 wt.% Al and 1.2 wt.% C has wear resistance comparable to within 5% of the bainitic SAE 8620 steel forging currently used for the Bradley Fighting Vehicle track shoe and this cast Fe-Mn-Al-C steel, at equivalent tensile properties, would be 10% lighter.

  15. Magmatic model for the Mount St. Helens blast of May 18, 1980

    Microsoft Academic Search

    J. C. Eichelberger; D. B. Hayes

    1982-01-01

    Analytical and numerical solutions to the hydrodynamic equations of motion, constrained by physical properties of juvenile ejecta in the Mount St. Helens blast deposit, were used to investigate magmatic conditions required to produce the initial devastating blast phase of the eruption of May 18, 1980. Evidence that the blast was magmatic includes equivalence in volume of juvenile blast ejecta to

  16. A Thoracic Mechanism of Mild Traumatic Brain Injury Due to Blast Pressure Waves

    Microsoft Academic Search

    Amy Courtney; Michael Courtney

    2008-01-01

    The mechanisms by which blast pressure waves cause mild to moderate traumatic brain injury (mTBI) are an open question. Possibilities include acceleration of the head, direct passage of the blast wave via the cranium, and propagation of the blast wave to the brain via a thoracic mechanism. The hypothesis that the blast pressure wave reaches the brain via a thoracic

  17. Latest Evolution in Blast Furnace Hearth thermo-Mechanical Stress Modelling Jrme BRULIN, Frdric ROULET (1)

    E-print Network

    Paris-Sud XI, Université de

    1 Latest Evolution in Blast Furnace Hearth thermo-Mechanical Stress Modelling Jérôme BRULIN.blond@univ-orleans.fr; alain.gasser@univ-orleans.fr Keywords: blast-furnace, modeling, hearth, ceramic cup Abstract Saint-Gobain has a long experience in the design and supply of blast furnace hearth linings. The Blast Furnace

  18. BLAST: at the core of a powerful and diverse set of sequence analysis tools

    E-print Network

    Narasimhan, Giri

    (http://www.ncbi.nlm.nih.gov/BLAST/). All the algorithm­database combinations can be executed- page (http://www.ncbi.nlm.nih.gov/BLAST/) lists the vari- eties of BLAST searches by type: Nucleotide version of this table (http://www.ncbi.nlm.nih.gov/blast/link_params.html), each cell of the top row

  19. Study of blasting vibrations in sarcheshmeh copper mine

    NASA Astrophysics Data System (ADS)

    Najm, K.; Javaherian, A.; Amnieh, H. B.

    2002-11-01

    Ground vibration is one of the side effects of blasting, in which way considerable amount of explosive energy is exhausted, and causes decrease in production and even decline in mine development workings. In this study, 57 recorded 3-C seismograms from 11 blasts in Sarcheshmeh copper mine, Kerman, Iran, are processed and analyzed. These data were recorded by digital seismograph PDAS-100 and analyzed by DADISP software. Finally, blasting parameters, such as explosive weight and type, distance between the structures and blasting site, blasting delays, affecting ground vibration are reviewed and their influence on peak particle velocity (PPV) are studied. Based on this study, suitable detonation delays and explosive type is determined. Considering these data, a graph of PPV versus scaled distance for Sarcheshmeh copper mine is prepared, by the help of which, safe distance for structures and accordingly explosive quantity could be determined.

  20. Studies of laser-driven radiative blast waves

    SciTech Connect

    Edwards, M J; Hansen, J; Edens, A; Ditmire, T; Adams, R; Rambo, P; Ruggles, L; Smith, I; Porter, J

    2004-04-29

    We have performed two sets of experiments looking at laser-driven radiating blast waves. In one set of experiments the effect of a drive laser's passage through a background gas on the hydrodynamical evolution of blast waves was examined. It was found that the laser's passage heats a channel in the gas, creating a region where a portion of the blast wave front had an increased velocity, leading to the formation of a bump-like protrusion on the blast wave. The second set of experiments involved the use of regularly spaced wire arrays to induce perturbations on a blast wave surface. The decay of these perturbations as a function of time was measured for various wave number perturbations and found to be in good agreement with theoretical predictions.