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1

Metallurgical Evaluation of Grit Blasted Versus Non-Grit Blasted Iridium Alloy Clad Vent Set Cup Surfaces  

Microsoft Academic Search

Metallurgical evaluations were conducted to determine what, if any, grain size differences exist between grit blasted and non-grit blasted DOP-26 iridium alloy cup surfaces and if grit blasting imparts sufficient compressive cold work to induce abnormal grain growth during subsequent temperature exposures. Metallographic measurements indicated that grit blasting cold worked the outside cup surface to a depth of approximately 19

George B Ulrich; Hu Foster Longmire

2010-01-01

2

Loose abrasive blasting as an alternative to slurry polishing of optical fibre end faces  

Microsoft Academic Search

A novel method of polishing the end face of an optical fibre by blasting it with loose dry abrasive grit travelling at high speeds is presented. The method, called loose abrasive blasting (LAB), is specifically designed to improve the surface quality of micro-lenses ground at the tips of optical fibres. Thus, the method described is suitable for polishing non-flat surfaces.

Yousef A Gharbia; Jayantha Katupitiya

2003-01-01

3

Air-propelled abrasive grit for postemergence in-row weed control in field corn  

Technology Transfer Automated Retrieval System (TEKTRAN)

Organic growers need additional tools for weed control. A new technique involving abrasive grit propelled by compressed air was tested in field plots. Grit derived from corn cobs was directed at seedlings of summer annual weeds growing at the bases of corn plants when the corn was at differing early...

4

Alumina grit blasting parameters for surface preparation in the plasma spraying operation  

NASA Astrophysics Data System (ADS)

This paper examines how the grit blasting process influences the surface roughness of different sub-strates, the grit residue, and the grit erosion. The influence of grit blasting conditions on induced sub-strate residual stresses is also discussed. Aluminum alloy, cast iron, and hard steel were blasted with white alumina grits of 0.5,1, and 1.4 mm mean diameters. Grit blasting was performed using either a suction-type or a pressure-type machine equipped with straight nozzles made of B4C. The influence of the follow-ing parameters was studied: grit blasting distance (56 to 200 mm), blasting time (3 to 30 s), angle between nozzle and blasted surface (30°, 60°, 90°), and blasting pressure (0.2 to 0.7 MPa). The roughness of the substrate was characterized either by using a perthometer or by image analysis. The grit residue remain-ing at the blasted surface was evaluated after cleaning by image analysis. The residual stresses induced by grit blasting were determined by using the incremental hole drilling method and by measuring the de-flection of grit-blasted beams. Grit size was determined to be the most important influence on roughness. The average values of Ra and Rt and the percentage of grit residue increased with grit size as well as the depth of the plastic zone under the substrate. An increase of the pressure slightly increased the values of Äa and Rt but also promoted grit breakdown and grit residue. A blasting time of 3 to 6 s was sufficient to obtain the highest roughness and limit the grit breakdown. The residual stresses generated under the blasted surface were compressive, and the depth of the affected zone depended on the grit diameter, the blasting pressure, and the Young’s modulus of the substrate. More-over, the maximum residual stress was reached at the limit of the plastic zone (i.e., several tenths of a mil-limeter below the substrate surface).

Mellali, M.; Grimaud, A.; Leger, A. C.; Fauchais, P.; Lu, J.

1997-06-01

5

Effect of Grit-Blasting on the Surface Energy of Graphite\\/Epoxy Composites  

Microsoft Academic Search

Contact-angle measurements were used to determine the surface energies of graphite\\/epoxy composites before and after grit-blasting with 80- and 220-grit garnet particles. Two different composite systems cured at 350°F were considered but they behaved similarly. Contact angles made by a series of liquids, including water, ethylene glycol, glycerol, formamide, and methylene iodide on as-tooled and grit-blasted composite panels were measured

F. J. Boerio; B. Roby; R. G. Dillingham; R. H. Bossi; R. L. Crane

2006-01-01

6

Influence of Grit Blasting on the Roughness and the Bond Strength of Detonation Sprayed Coating  

Microsoft Academic Search

The process of roughening the surfaces by grit blasting prior to coating them using thermal spray techniques is very important\\u000a to obtain consistently high tensile bond strength between the coating and the substrate. The available literature on the influence\\u000a of grit-blasting parameters in the case of detonation spray or HVOF coatings is quite limited. The present study aims to study

D. Sen; Naveen M. Chavan; D. S. Rao; G. Sundararajan

2010-01-01

7

Biological fixation of hydroxyapatite-coated versus grit-blasted titanium hip stems: a canine study  

Microsoft Academic Search

Background. The purpose of the study was to evaluate the influence of a proximal hydroxyapatite (HA) coating in comparison with a grit-blasted titanium surface of an anatomic hip stem in an animal model over a maximum duration of 2 years. Methods. Thirty adult dogs underwent implantation of either a proximally HA-coated or a grit-blasted anatomic titanium stem. The animals were

Anke Eckardt; Harold M. Aberman; Dan H. Cantwell; Jochen Heine

2003-01-01

8

Abrasive Blasting Agents: Designing Studies to Evaluate Relative Risk  

Microsoft Academic Search

Workers exposed to respirable crystalline silica used in abrasive blasting are at increased risk of developing a debilitating and often fatal fibrotic lung disease called silicosis. The National Institute for Occupational Safety and Health (NIOSH) recommends that silica sand be prohibited as abrasive blasting material and that less hazardous materials be used in blasting operations. However, data are needed on

Ann Hubbs; Mark Greskevitch; Eileen Kuempel; Fernando Suarez; Mark Toraason

2005-01-01

9

The manufacture and fatigue cracking resistance of grit free aluminide diffusion coatings  

Microsoft Academic Search

Abrasive blasting is an inexpensive and effective means of cleaning superalloy castings, and of roughening the surface of these castings prior to platinum electroplating or overlay coating deposition. However, during the blasting operations, some of the abrasive grit particles become embedded in the surface of the superalloy and this embedded grit can result in detrimental effects on the mechanical properties

Bruce M Warnes; Andrew L Purvis; John E Schilbe

2003-01-01

10

Supersonic fan nozzle for abrasive blasting media  

US Patent & Trademark Office Database

A supersonic fan nozzle for abrasive blast removal of coatings particularly for use with plastic abrasive media, provides much greater media particle velocity, a more uniform velocity profile, and a more uniform media particle distribution than prior art nozzles. The new nozzle has a constant height throat area about 1 inch long, about 1.57 inches wide, and about 0.125 inche high. The throat opens into a constant height diverging slot which diverges at about a 6.5 degree half-angle for about 9.5 inches to a final exit width of about 3.75 inches. A nozzle-to-hose coupling connects at one end to a conventionally sized blasting hose and at the other by a rectangular opening to the throat. Used with light plastic media entrained in an airflow stream at operating pressures of 15 to 80 psig, the nozzle has successfully removed coatings from a variety of delicate underlying substrates with little or no observable damage to the substrates. In tests, it has produced minimal residual stress effects on substrates while increasing production stripping rates by 50-200% . Tests have shown that the optimum range of dimensions for the new nozzle are a slot exit area to throat area ratio about 2.2 to about 2.5 and a constant divergence half-angle of about 5 to about 8 degrees.

1994-12-06

11

Simulation and Improvement of the Micro Abrasive Blasting Process  

Microsoft Academic Search

Micro abrasive blasting (MAB) is becoming an important machining technique for the fabrication of Micro Electro Mechanical systems. The process is based on the erosion of a mask-protected brittle substrate by an abrasive-laden air jet. Currently available blasting machines are relatively simple. However, to exploit this technique for applications of industrial interest a more efficient and controllable process is required.

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

2004-01-01

12

Modelling and evaluation of the micro abrasive blasting process  

Microsoft Academic Search

Micro abrasive blasting (MAB) is becoming an important machining technique for the cost effective fabrication of micro devices. The material removal process is based on the erosion of a mask-protected brittle substrate by an abrasive-laden air jet. To exploit the potentials of this technique for applications of industrial interest, the blasting process has to become more efficient and better predictable.

M. Achtsnick; P. F. Geelhoed; A. M. Hoogstrate; B. Karpuschewski

2005-01-01

13

Development of a thermal reclamation system for spent blasting abrasive  

SciTech Connect

Abrasive blasting is the most economical method for paint removal from large surface areas such as the hulls and tanks of oceangoing vessels. Tens of thousands of tons of spent abrasive are generated annually by blasting operations in private and US Navy shipyards. Some of this material is classified as hazardous waste, and nearly all of it is currently being either stockpiled or disposed in landfills. The rapid decline in available landfill space and corresponding rise in landfill tipping fees pose a severe problem for shipyard operators throughout the US. This paper discusses the results of a research and development program initiated by the Institute of Gas Technology and supported by the US Navy to develop and test a fluidized-bed thermal reclamation system for spent abrasive waste minimization. Bench- and pilot-scale reclaimer tests and reclaimed abrasive performance tests are described along with the current status of a program to build and test a 5-ton/hour prototype reclaimer at a US Navy shipyard.

Bryan, B.B.; Mensinger, M.C.; Rehmat, A.G.

1991-01-01

14

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

SciTech Connect

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.

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

1981-11-16

15

A Review of Engineering Control Technology for Exposures Generated During Abrasive Blasting Operations  

Microsoft Academic Search

This literature review presents information on measures for controlling worker exposure to toxic airborne contaminants generated during abrasive blasting operations occurring primarily in the construction industry. The exposures of concern include respirable crystalline silica, lead, chromates, and other toxic metals. Unfortunately, silica sand continues to be widely used in the United States as an abrasive blasting medium, resulting in high

Michael R. Flynn; Pam Susi

2004-01-01

16

Effect of Abrasive Blasting on the Fatigue and Corrosion of an Aluminium-Copper Alloy.  

National Technical Information Service (NTIS)

Rotating bending fatigue tests have established that glass bead and alumina grit blasting have only a slight effect on the fatigue properties of 2014-T6 aluminium alloy. Exposure to salt fog for 8 hours or alternate immersion in 3 1/2% salt solution for 3...

C. J. E. Smith M. A. H. Hewins

1984-01-01

17

Abrasive micro-blasting to improve surface integrity of electrical discharge machined WC–Co composite  

Microsoft Academic Search

This study investigates the improvement of surface integrity of wire electrical discharge machined (EDM) WC–Co composite by abrasive micro-blasting. The thermally damaged recast layer generated by EDM has craters, cracks, and bubbles, which deteriorate the surface mechanical properties. The micro-blasting, using 6–12 and 4–20?m size SiC abrasive, enables the removal of the recast layer and is suitable for micro mechanical

Jun Qu; Albert J. Shih; Ronald O. Scattergood; Jie Luo

2005-01-01

18

Influence of Abrasive Blast Cleaning and Corrosion Inhibitors on Protective Paint Coatings.  

National Technical Information Service (NTIS)

Wet blast cleaning of steel surfaces results in flash rusting and to combat this problem, water soluble inhibitors are used. It was suggested that inhibitors could be improved and to investigate this problem, it was necessary to produce abrasive blast cle...

A. R. Amey

1984-01-01

19

Fibrogenic potential of slags used as substitutes for sand in abrasive blasting operations  

Microsoft Academic Search

The fibrogenic potentials of coal and copper slags used as substitutes for silica sand in abrasive blasting operations were assessed in rats. The test animals were given a single pulmonary intralobar instillation of 20?mg of test material and were sacrificed 10 months after dosing. Pulmonary fibrosis was seen in the coal slag-treated rats while no fibrosis was seen in the

GEORGE R. MACKAY; LLOYD E. STETTLER; CHOUDARI KOMMINENI; HARRY M. DONALDSON

1980-01-01

20

The effect of bond coat grit blasting on the durability and thermally grown oxide stress in an electron beam physical vapor deposited thermal barrier coating  

Microsoft Academic Search

Photo-stimulated luminescence Piezo-spectroscopy (PLPS) is being developed as a non-destructive technique for thermal barrier coatings (TBC). In this study, the evolution of photo-stimulated luminescence with thermal cycling was systematically investigated from the thermally grown oxide (TGO) in a production TBC, which consists of an electron beam physical vapor deposited (EB-PVD) 7 wt.% Y2O3–ZrO2 top coat, a grit blasted (Ni,Pt)Al bond

Liangde Xie; Yongho Sohn; Eric H. Jordan; Maurice Gell

2003-01-01

21

Mechanical and histological evaluation of hydroxyapatite-coated, titanium-coated and grit-blasted surfaces under weight-bearing conditions  

Microsoft Academic Search

Cylindric titanium rods with different surfaces were axially implanted into the femora of sheep. The three surfaces were grit-blasted titanium, plasma-sprayed titanium and plasma-sprayed hydroxyapatite (HA). After 2 months, a 2-cm segment of the femoral shaft was completely resected to load the implant, and the animals were allowed full weight-bearing for 9 months. Biomechanical and histological evaluation of the implants

A. Dávid; J. Eitenmüller; G. Muhr; A. Pommer; H. F. Bär; P. A. W. Ostermann; T. A. Schildhauer

1995-01-01

22

Grit-blasted and hydroxyapatite-coated total hip arthroplasty: an 11- to 14-year follow-up study.  

PubMed

We report long-term results of the first clinical trial of hydroxyapatite-coated total hip arthroplasty conducted in Japan. The hemispherical cup and the straight-tapered stem were made of titanium alloy with a grit-blasted, hydroxyapatite-coated surface. The surface roughness before and after hydroxyapatite coating was 1.4 microm and 3.4 microm, respectively. Thirty-three patients (35 hips) were followed prospectively; of these, 1 patient was lost to follow-up, 5 were deceased at the latest follow-up, and 27 were followed for 11 to 14 years. Two cups and one stem (two patients) were revised. Survivorship, with radiological acetabular loosening as the endpoint, was 62.3% at 14 years. At the latest radiological follow-up, stable fixation with bone ongrowth was achieved in 46% of the acetabular cups and 89% of the femoral stems. Acetabular cups with host bone coverage of less than 60% had a high rate of failure. The suboptimal result of the hydroxyapatite-coated smooth cup indicates that porous coatings under the hydroxyapatite coating would be beneficial for hydroxyapatite-coated total hip implants, especially for the acetabular components. PMID:15449121

Miyakawa, Shumpei; Kawamura, Haruo; Mishima, Hajime; Yasumoto, Jun

2004-01-01

23

A wet abrasive blasting process for smooth micromachining of glass by ductile-mode removal  

NASA Astrophysics Data System (ADS)

This paper describes the ductile removal behavior of a Pyrex glass substrate in a wet blasting process with an aqueous fine abrasive slurry of 4 µm Al2O3 particles in water. Glass was removed in a ductile cutting mode when the blasting was carried out with low applied pressure or with a long nozzle distance. Although the removal rate in the ductile mode was much lower than with brittle-mode blasting, a smooth surface within a roughness of 50 nm Ra was obtained. Using ductile-mode blasting, a micro groove with a smooth surface (roughness <50 nm Ra) was successfully obtained. The profile of the micro groove was U-shaped, in contrast to the V-shaped profile obtained with conventional brittle-mode blasting. Ductile-mode blasting was also used for surface finishing after a rough pre-blasting process. The roughness of the pre-blasted surface was reduced from 200 nm Ra to about 100 nm Ra by the finishing process.

Mineta, Takashi; Takada, Takehisa; Makino, Eiji; Kawashima, Takahiro; Shibata, Takayuki

2009-01-01

24

Study on cylindrical magnetic abrasive finishing using unbonded magnetic abrasives  

Microsoft Academic Search

The process principle and the finishing characteristics of unbonded magnetic abrasive within cylindrical magnetic abrasive finishing are described in this study. The unbonded magnetic abrasive is a mechanical mixture of SiC abrasive and ferromagnetic particles with a SAE30 lubricant. Iron grit and steel grit, for which three various particle sizes were prepared for both, were used as ferromagnetic particles, each

Geeng-Wei Chang; Biing-Hwa Yan; Rong-Tzong Hsu

2002-01-01

25

Superficial severe plastic deformation of 316 LVM stainless steel through grit blasting: Effects on its microstructure and subsurface mechanical properties  

Microsoft Academic Search

The microstructure and mechanical properties of austenitic stainless steel 316 LVM (Low Vacuum Melting) blasted with either small and rounded ZrO2 particles or larger and angular shaped Al2O3 particles are analysed through magnetic force microscopy, synchrotron radiation diffraction and ultramicroindentation techniques. It is shown that blasting causes a severe plastic deformation that roughens the surface and produces a significant subsurface

M. Multigner; S. Ferreira-Barragáns; E. Frutos; M. Jaafar; J. Ibáñez; P. Marín; M. T. Pérez-Prado; G. González-Doncel; A. Asenjo; J. L. González-Carrasco

2010-01-01

26

Abrasives  

Microsoft Academic Search

\\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

Masakatsu Asami; Michael Santorelli

2010-01-01

27

Effect of substrate roughness induced by grit blasting upon adhesion of WC-17% Co thermal sprayed coatings  

Microsoft Academic Search

WC-Co thermally sprayed coatings are often used for their high hardness and resistance to abrasion and erosion-induced wear. Several compositions ranging mostly from 12 to 18% Co are commercially available and numerous studies have reported the changes in hardness and wear properties in relation to these compositions. A great number of parameters influence functional as well as adhesive properties of

M. H. Staia; E. Ramos; A. Carrasquero; A. Roman; J. Lesage; D. Chicot; G. Mesmacque

2000-01-01

28

Bone-added osteotome sinus floor elevation with simultaneous placement of non-submerged sand blasted with large grit and acid etched implants: a 5-year radiographic evaluation  

PubMed Central

Purpose Implant survival rates using a bone-added osteotome sinus floor elevation (BAOSFE) procedure with simultaneous placement of a non-submerged sand blasted with large grit and acid etched (SLA) implant are well documented at sites where native bone height is less than 5 mm. This study evaluated the clinical results of non-submerged SLA Straumann implants placed at the time of the BAOSFE procedure at sites where native bone height was less than 4 mm. Changes in graft height after the BAOSFE procedure were also assessed using radiographs for 5 years after the implant procedure. Methods The BAOSFE procedure was performed on 4 patients with atrophic posterior maxillas with simultaneous placement of 7 non-submerged SLA implants. At least 7 standardized radiographs were obtained from each patient as follows: before surgery, immediately after implant placement, 6 months after surgery, every year for the next 3 years, and after more than 5 years had passed. Clinical and radiographic examinations were performed at every visit. Radiographic changes in graft height were calculated with respect to the implant's known length and the original sinus height. Results All implants were stable functionally, as well as clinically and radiographically, during the follow-up. Most of the radiographic reduction in the grafted bone height occurred in the first 2 years; reduction after 2 years was slight. Conclusions The simultaneous placement of non-submerged SLA implants using the BAOSFE procedure is a feasible treatment option for patients with severe atrophic posterior maxillas. However, the grafted bone height is reduced during the healing period, and patients must be selected with care.

Jung, Jee-Hee; Choi, Seong-Ho; Cho, Kyoo-Sung

2010-01-01

29

Abrasive blasting, a technique for the industrial decontamination of metal components and concrete blocks from decommissioning to unconditional release levels  

SciTech Connect

When decommissioning nuclear installations, large quantities of metal components are produced as well as significant amounts of other radioactive materials, which mostly show low surface contamination. Having been used or having been brought for a while in a controlled area marks them as 'suspected material'. In view of the very high costs for radioactive waste processing and disposal, alternatives have been considered, and much effort has gone to recycling through decontamination, melting and unconditional release of metals. In a broader context, recycling of materials can considered to be a first order ecological priority in order to limit the quantities of radioactive wastes for final disposal and to reduce the technical and economic problems involved with the management of radioactive wastes. It will help as well to make economic use of primary material and to conserve natural resources of basic material for future generations. In a demonstration programme, Belgoprocess has shown that it is economically interesting to decontaminate metal components to unconditional release levels using dry abrasive blasting techniques, the unit cost for decontamination being only 30 % of the global cost for radioactive waste treatment, conditioning, storage and disposal. As a result, an industrial dry abrasive blasting unit was installed in the Belgoprocess central decontamination infrastructure. At the end of December 2006, more than 1,128 Mg of contaminated metal has been treated as well as 313 Mg of concrete blocks. The paper gives an overview of the experience relating to the decontamination of metal material and concrete blocks at the decommissioning of the Eurochemic reprocessing plant in Dessel, Belgium as well from the decontamination of concrete containers by abrasive blasting. (authors)

Gills, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R. [Belgoprocess N.V., Gravenstraat 73, 2480 Dessel (Belgium)

2007-07-01

30

State-of-the-Science Review of the Occupational Health Hazards of Crystalline Silica in Abrasive Blasting Operations and Related Requirements for Respiratory Protection  

Microsoft Academic Search

Excessive exposures to airborne crystalline silica have been known for over 100 years to pose a serious health hazard. Work practices and regulatory standards advanced as the knowledge of the hazards of crystalline silica evolved. This article presents a comprehensive historical examination of the literature on exposure, health effects, and personal protective equipment related to silica and abrasive blasting operations

Amy K. Madl; Ellen P. Donovan; Shannon H. Gaffney; Meg A. McKinley; Emily C. Moody; John L. Henshaw; Dennis J. Paustenbach

2008-01-01

31

Loose abrasive truing and dressing of resin bond diamond cup wheels for grinding fibre optic connectors  

Microsoft Academic Search

A loose abrasive lapping technology was developed for truing and dressing ultrafine diamond cup wheels for grinding spherical end faces of fibre optic connectors. The relative densities of exposed grits and grit pull-outs measured from wheel surfaces prepared using the loose abrasive lapping and the bonded abrasive dressing were compared. It was found that the lapping method with loose abrasives

W. K. Chen; H. Huang; L. Yin

2005-01-01

32

State-of-the-science review of the occupational health hazards of crystalline silica in abrasive blasting operations and related requirements for respiratory protection.  

PubMed

Excessive exposures to airborne crystalline silica have been known for over 100 years to pose a serious health hazard. Work practices and regulatory standards advanced as the knowledge of the hazards of crystalline silica evolved. This article presents a comprehensive historical examination of the literature on exposure, health effects, and personal protective equipment related to silica and abrasive blasting operations over the last century. In the early 1900s, increased death rates and prevalence of pulmonary disease were observed in industries that involved dusty operations. Studies of these occupational cohorts served as the basis for the first occupational exposure limits in the 1930s. Early exposure studies in foundries revealed that abrasive blasting operations were particularly hazardous and provided the basis for many of the engineering control and respiratory protection requirements that are still in place today. Studies involving abrasive blasters over the years revealed that engineering controls were often not completely effective at reducing airborne silica concentrations to a safe level; consequently, respiratory protection has always been an important component of protecting workers. During the last 15-20 yr, quantitative exposure-response modeling, experimental animal studies, and in vitro methods were used to better understand the relationship between exposure to silica and disease in the workplace. In light of Occupational Safety and Health Administration efforts to reexamine the protectiveness of the current permissible exposure limit (PEL) for crystalline silica and its focus on protecting workers who are known to still be exposed to silica in the workplace (including abrasive blasters), this state-of-the-science review of one of the most hazardous operations involving crystalline silica should provide useful background to employers, researchers, and regulators interested in the historical evolution of the recognized occupational health hazards of crystalline silica and abrasive blasting operations and the related requirements for respiratory protection. PMID:18584454

Madl, Amy K; Donovan, Ellen P; Gaffney, Shannon H; McKinley, Meg A; Moody, Emily C; Henshaw, John L; Paustenbach, Dennis J

2008-08-01

33

Abrasive flow finishing of stereolithography prototypes  

Microsoft Academic Search

This research investigated the use of two relatively new technologies, abrasive flow machining (AFM) and stereolithography (SL), to minimize the time to develop a finished prototype. Statistical analysis was used to determine effects of media grit size, media pressure, build style, build orientation and resin type on flatness, material removal rate and surface roughness. Results indicated that media pressure, grit

Robert E. Williams; Vicki L. Melton

1998-01-01

34

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 ...

35

Scarification and Degermination of Sorghum for Grits Production: Effects of Hybrid and Conditioning 1  

Microsoft Academic Search

Cereal Chem. 77(6):808-815 Three sorghum hybrids were tempered and decorticated with an abrasive- type mill (scarifier) to pr oduce low-ash and low-fat grits. The effects of tempering time and temperature were investigated, and the optimum tempering conditions for obtaining low-ash and low-fat grits were found for each sorghum hybrid. The conditions were 3 min at 30°C for bronze sorghum with

Janti Suroso; Rolando A. Flores; John E. Boyer

2000-01-01

36

Estimation of the minimum machining performance in the abrasive waterjet machining using integrated ANN-SA  

Microsoft Academic Search

In this study, Artificial Neural Network (ANN) and Simulated Annealing (SA) techniques were integrated labeled as integrated ANN-SA to estimate optimal process parameters in abrasive waterjet (AWJ) machining operation. The considered process parameters include traverse speed, waterjet pressure, standoff distance, abrasive grit size and abrasive flow rate. The quality of the cutting of machined-material is assessed by looking to the

Azlan Mohd Zain; Habibollah Haron; Safian Sharif

2011-01-01

37

A study on surface roughness in abrasive waterjet machining process using artificial neural networks and regression analysis method  

Microsoft Academic Search

In the present study, artificial neural network (ANN) and regression model were developed to predict surface roughness in abrasive waterjet machining (AWJ) process. In the development of predictive models, machining parameters of traverse speed, waterjet pressure, standoff distance, abrasive grit size and abrasive flow rate were considered as model variables. For this purpose, Taguchi's design of experiments was carried out

Ula? Çayda?; Ahmet Hasçal?k

2008-01-01

38

Abrasive wear of alumina fibre-reinforced aluminium  

NASA Astrophysics Data System (ADS)

The friction and abrasive wear behaviour of an Al-Si1MgMn aluminium alloy reinforced with 10, 15 and 30 vol.% of alumina fibers has been evaluated. The influence of fiber content, matrix hardness, applied load as well as the hardness and size of the abrasive grits was investigated. The tests were performed with a pin-on-drum two-body abrasion apparatus. The wear mechanisms were studied using scanning electron microscopy. It is shown that fiber reinforcement increases the wear resistance in milder abrasive situations, i.e. small and soft abrasives and low loads. However, in tougher abrasive situations, meaning coarse and hard abrasives and high loads, the wear resistance of the composites is equal to or, in some cases, even lower than that of the unreinforced material. It is also shown that the coefficient of friction decreases with increasing fiber content and matrix hardness of the composites.

Axen, N.; Alahelisten, A.; Jacobson, S.

1994-04-01

39

Plastic Media Blasting - An alternative for coating removal  

Microsoft Academic Search

Plastic Media Blasting (PMB) is a revolutionary method for the rapid and safe removal of primer, paint and even powder and other chemically resistant coatings from a vast range of products without the use of toxic chemicals or pneumatic blasting with hard abrasives. Although resembling sand-blasting, PMB does not use the hard abrasives or high pressures of that process. Instead,

Kenneth E. Abbott

1989-01-01

40

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...

41

Plastic Media Blasting - An alternative for coating removal  

NASA Astrophysics Data System (ADS)

Plastic Media Blasting (PMB) is a revolutionary method for the rapid and safe removal of primer, paint and even powder and other chemically resistant coatings from a vast range of products without the use of toxic chemicals or pneumatic blasting with hard abrasives. Although resembling sand-blasting, PMB does not use the hard abrasives or high pressures of that process. Instead, PMB uses reusable plastic particles which are applied at pressures of 20 to 40 psi. The unique abrasive blast media not only replaces potentially hazardous abrasives such as silica sand, but since it is reusable it also generates less overall waste material.

Abbott, Kenneth E.

1989-03-01

42

7 CFR 3201.78 - Blast media.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Blast media. 3201.78 Section 3201.78 Agriculture... Designated Items § 3201.78 Blast media. (a) Definition. Abrasive particles...preference for qualifying biobased blast media. By that date, Federal agencies...

2013-01-01

43

Facilities Used for Plastic Media Blasting.  

National Technical Information Service (NTIS)

The equipment used for plastic media blasting (PMB) is generally independent of the media and is similar to equipment used in traditional abrasive blasting. PMB equipment is usually modified to enable the close control of the media flow and the operation ...

T. Foster

1995-01-01

44

High resolution powder blast micromachining  

Microsoft Academic Search

Powder blasting, or Abrasive Jet Machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials like glass, silicon and ceramics. By introducing electroplated copper as a new mask material, the feature size of this process was decreased. It

Henk Wensink; J. W. Berenschot; Henri V. Jansen; Miko C. Elwenspoek

2000-01-01

45

The effect of particle feed rate on the plastic media blast jet  

Microsoft Academic Search

Paint removal from military aircraft is often done by plastic media blasting (PMB): the use of plastic grit in a conventional blast jet. However, there is some concern that PMB will cause damage. To help in evaluating this possibility, a time of flight'' meter is used to measure particle velocity in the jet, as a function of air pressure, distance

M. J. McIntosh

1992-01-01

46

Reduction of sidewall inclination and blast lag of powder blasted channels  

Microsoft Academic Search

Powder blasting (abrasive jet machining) is a fast directional machining technique for brittle materials like silicon and glass. The cross-section of a powder blasted channel has a rounded V-shape. These inclined sidewalls are caused by the typical impact angle dependent removal rate for brittle materials. It has a negative influence on the channel depth and aspect ratio, and results in

Henk Wensink; Miko C. Elwenspoek

2002-01-01

47

Blast Injuries  

MedlinePLUS

... blast over-pressurization wave travels at a high velocity and is affected by the environment; for example, ... injuries are similar to those observed following high-speed motor vehicle accidents. Quaternary blast injury can occur ...

48

Enhancing Oil Production by Helical Hydraulic Sand-Blasting  

Microsoft Academic Search

The helical hydraulic sand-blasting slotting technology is a new development of the traditional hydraulic sand-blasting slotting technology. The original nozzle gun movement control system was replaced with a helical slid rail, and thus the application was extended to directional and horizontal wells. Experiments were conducted to study the feasibility abrasive water jet slotting sand prevention tubes. The effects of slotting

G. Li; J. Song; J. Niu; R. Tang; Z. Huang

2007-01-01

49

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

Microsoft Academic Search

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,

Y. Sahin; K. Ozdin

2004-01-01

50

Electrolytic magnetic abrasive finishing  

Microsoft Academic Search

Electrolytic magnetic abrasive finishing (EMAF) is a compound finishing process, involving traditional magnetic abrasive finishing (MAF) and an electrolytic process. The aim of including the electrolytic process into the EMAF system is to produce a passive film (or oxide film), which is much easier to remove than the original metal surface during processing. Moreover, in the presence of both electric

Biing-Hwa Yan; Geeng-Wei Chang; Tsung-Jen Cheng; Rong-Tzong Hsu

2003-01-01

51

Mask materials for powder blasting  

NASA Astrophysics Data System (ADS)

Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials such as glass, silicon and ceramics. The particle jet (which expands to about 1 cm in diameter) can be optimized for etching, while the mask defines the small and complex structures. The quality of the mask influences the performance of powder blasting. In this study we tested and compared several mask types and added a new one: electroplated copper. The latter combines a highly resistant mask material for powder blasting with the high-resolution capabilities of lithography, which makes it possible to obtain an accurate pattern transfer and small feature sizes (<50 µm).

Wensink, Henk; Jansen, Henri V.; Berenschot, J. W.; Elwenspoek, Miko C.

2000-06-01

52

GRIT-USE PATTERNS IN NORTH AMERICAN BIRDS: THE INFLUENCE OF DIET BODY SIZE AND GENDER  

Microsoft Academic Search

ABSTRACT.-we,investigated avian,grit use by examining,the gizzard contents of 1440 birds collected from,12 states. Grit was,present in gizzards of 62 of 90 species and varied greatly in number,and mean,particle size. Gizzards of granivorous,birds contained more,grit particles than those of insectivores, omnivores, and frugivores. Grit particle characteristics (mean size, shape, and surface texture) did not differ among birds consuming different diets. Mean

James I Gionfriddo; Louis B. Best

53

Solidification/stabilization of spent abrasives and use as nonstructural concrete  

SciTech Connect

Tons of spent abrasives result each year from the removal of old paint from bridges. Because the spent abrasives contain metals from the paint, some spent abrasives may be considered hazardous by the Toxicity Characteristic (TC) criteria. Incorporation of the spent blasting abrasives in nonstructural concrete (rip-rap, dolphins) offers an opportunity to recycle the spent abrasives while immobilizing potentially leachable metals. This study focused on the Portland Cement Solidification/Stabilization (S/S) of spent blasting abrasives taken from a bridge located in Southeast Texas. The study examined (a) the cadmium, chromium, and lead concentrations in extracts obtained by using the Toxicity Characteristic Leaching Procedure (TCLP) and (b) the compressive strengths of Portland Cement mixes that contained different amounts of the spent abrasives. Performance was measured by meeting the TC criteria as well as the requirements for compressive strength. Study results indicated that considerable quantities of these spent abrasives can be solidified/stabilized while reducing the leachability of cadmium, chromium, and lead and producing compressive strengths over 6,895 kN/m[sup 2] (1,000 psi).

Brabrand, D.J.; Loehr, R.C. (Univ. of Texas, Austin, TX (United States))

1993-01-01

54

Grit Particle Enhanced Non-Shock Ignition of Explosives  

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

55

Turkana Grits - a Cretaceous braided alluvial system in northern Kenya  

Microsoft Academic Search

Rather spotty but excellent exposures of the Cretaceous-age Turkana Grits occur near the western shore of Lake Turkana, northern Kenya. These very coarse to pebbly arkosic sandstones and sandy conglomerates were derived from and rest unconformably upon Precambrian metamorphic basement; they are overlain by late Tertiary basaltic flows that comprise much of the volcanics in the East African Rift Zone.

Handford

1987-01-01

56

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

Microsoft Academic Search

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

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

2010-01-01

57

The osseous response to corundum blasted implant surfaces in a canine hip model.  

PubMed

The purpose of this study was to examine the radiographic and histologic response to corundum blasted implant surfaces of varying roughness in a canine total hip arthroplasty model. Three types of tapered femoral implants were made from titanium alloy and were identical in every respect except surface finish. The entire surface of the femoral implant had a 2.9-, 4.2-, or 6.7-micron average surface roughness (Ra) from blasting with 60-, 24-, or 16-grit corundum particles, respectively. Twenty-two stems in 11 dogs were evaluated at 6 months. Twenty-one of the stems showed osseointegration, whereas in one stem a fibrous interface developed. Abundant new periimplant bone formation occurred, particularly within the intramedullary canal where trabeculae spanned implant to endosteal cortex gaps as large as 5 mm. Bone apposition with the 60-, 24-, and 16-grit stems averaged 31.7%, 32%, and 27.9%, respectively; the differences were not statistically significant. However, the pattern of new bone formation was different in that the average length of each region of bone apposition for the 60- and 24-grit surfaces was 50% greater than that for the coarser 16-grit surface. The observations of this study indicate that because of their highly osteoconductive nature, corundum blasted surfaces represent an important and valuable technology for the design of noncemented implants. PMID:10416415

Hacking, S A; Bobyn, J D; Tanzer, M; Krygier, J J

1999-07-01

58

Ultrasonic abrasion of quartz crystals  

Microsoft Academic Search

In the present work, we investigate the wear mechanisms associated with the ultrasonic abrasion of quartz. Ultrasonic abrasion was carried out in X-, Y-, Z- and AT-cut plates of natural quartz and Z-cut plates of synthetic quartz. The counter bodies, square and cylindrical, were fabricated from stainless steel. The abrasive slurry was made from boron carbide with mean grain size

P. L Guzzo; A. A Raslan; J. D. B De Mello

2003-01-01

59

Abrasion resistant heat pipe  

Microsoft Academic Search

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

Donald M

1984-01-01

60

Valve for abrasive material  

SciTech Connect

A ball valve assembly is disclosed 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.

Gardner, H.S.

1982-08-31

61

Abrasion resistant heat pipe  

DOEpatents

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.

Ernst, D.M.

1984-10-23

62

Perimeter blasting in granite with holes with axial notches and radial bottom slots  

Microsoft Academic Search

Five single perimeter rows, each with 8–13, 2-3 m deep Ø 64 mm holes have been blasted in a granite quarry to develop a technique for perimeter blasting with slotted holes that decreases the blast damage primarily in road cuts and consequently the maintenance costs. Most holes had radial bottom slots, which were cut with high-pressure abrasive water jets. The

Finn Ouchterlony; Mats Olsson; S. O. Båvik

2000-01-01

63

Plastic media blasting activities at Hill Air Force Base  

Microsoft Academic Search

Hill Air Force Base in Utah developed plastic media blasting (PMB) paint removal process for removing paint from Air Force aircraft. The development of the process involved extensive testing of various abrasives and subsequent parameters to end up with an approved production process. Hill AFB has been using PMB in a production mode since 1985, and completely discontinued chemical stripping

J. D. Christensen

1993-01-01

64

Four Variables Affecting Magnitude of Dentrifice Abrasiveness  

Microsoft Academic Search

Abrasion studies were done to evaluate which factors in addition to dentifrice abrasive will affect the wear caused by brushing dentin with abrasives. The factors were concentration, diluent, brush brand, brush hardness, and temperature of testing. Hard brushes were found to cause higher abrasion and glycerine to cause low abrasion. Concentration, brush brand, and temperature were significant influences and there

D. B. Harte; R. S. Manly

1976-01-01

65

Blast injury.  

PubMed

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

de Candole, C A

1967-01-28

66

Blast Injury  

PubMed Central

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.

de Candole, C. A.

1967-01-01

67

Evaluating the abrasion resistance of coatings with abrasive finishing tape  

Microsoft Academic Search

Abrasion resistance is often a coating or surface treatment's most important characteristic. Unfortunately, most of the many abrasion tests that exist were not developed for use on thin coatings and surface treatments (The test development and modifications are described and test data are presented on typical hard coatings (anodize, PVD TiN, chromium, etc.). The test is simple, fast, and it

Kenneth G. Budinski

2004-01-01

68

PARTICLES DURING SIMULATED ABRASIVE CLEANING  

Microsoft Academic Search

Most people clean their teeth using toothpaste, consisting of abrasive particles in a carrier fluid, and a filament based toothbrush to remove plaque and stain. In order to optimise cleaning efficiency it is important to understand how toothbrush filaments, abrasive particles and fluid interact in a tooth cleaning contact. Work has been carried out to visualise, simulate, and model the

R. LEWIS; R. S. DWYER-JOYCE

69

Turkana Grits - a Cretaceous braided alluvial system in northern Kenya  

SciTech Connect

Rather spotty but excellent exposures of the Cretaceous-age Turkana Grits occur near the western shore of Lake Turkana, northern Kenya. These very coarse to pebbly arkosic sandstones and sandy conglomerates were derived from and rest unconformably upon Precambrian metamorphic basement; they are overlain by late Tertiary basaltic flows that comprise much of the volcanics in the East African Rift Zone. The formation ranges up to 2000 ft thick in the Laburr Range. Several outcrops contain sauropod, crocodile, and tortoise remains as well as abundant trunks of petrified wood (Dryoxylon). Five major facies make up the Turkana Grits and record a major episode of continental fluvial deposition in basins flanked by Precambrian basement. Facies 1 is crudely stratified, cobble and boulder conglomerate (clast-supported); Facies 2 is crudely stratified pebble-cobble conglomerate and pebbly sandstone; Facies 3 is trough cross-bedded, very coarse sandstones containing fossils wood and vertebrate remains; Facies 4 is crudely stratified to massive sandstones with ironstone nodules; and Facies 5 is red, purple, and gray mudstone and mud shale with carbonate nodules. Facies 1 through 3 record deposition in proximal to medial braided-stream channel, longitudinal bar and dune complexes. Facies 4 is a lowland, hydromorphic paleosol, and Facies 5 represents overbank and abandoned channel-fill sedimentation in an alluvial plain.

Handford, C.R.

1987-05-01

70

Reduced toxicity of fumonisin B1 in corn grits by single-screw extrusion  

Technology Transfer Automated Retrieval System (TEKTRAN)

Extrusion cooking under conditions of high heat and pressure reduces the concentration of fumonisins in corn-based products; however, the toxicity of heretofore uncharacterized fumonisin reactions products in extruded materials has not been determined. Uncontaminated corn grits, grits spiked with 3...

71

The effect of extrusion on the fumonisin content and toxicity of corn grits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Extrusion cooking reduces fumonisin concentrations in corn; however, the nature and toxicity of fumonisin reaction products in food matrices are not well understood. Corn grits were contaminated by spiking with fumonisin B1 (FB1) (Spiked grits = SG, 43 nmol/g dry wt FB1; measured by LC-MS) or by fer...

72

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

SciTech Connect

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.

NONE

1997-07-31

73

Brain injuries from blast.  

PubMed

Traumatic brain injury (TBI) from blast produces a number of conundrums. This review focuses on five fundamental questions including: (1) What are the physical correlates for blast TBI in humans? (2) Why is there limited evidence of traditional pulmonary injury from blast in current military field epidemiology? (3) What are the primary blast brain injury mechanisms in humans? (4) If TBI can present with clinical symptoms similar to those of Post-Traumatic Stress Disorder (PTSD), how do we clinically differentiate blast TBI from PTSD and other psychiatric conditions? (5) How do we scale experimental animal models to human response? The preponderance of the evidence from a combination of clinical practice and experimental models suggests that blast TBI from direct blast exposure occurs on the modern battlefield. Progress has been made in establishing injury risk functions in terms of blast overpressure time histories, and there is strong experimental evidence in animal models that mild brain injuries occur at blast intensities that are similar to the pulmonary injury threshold. Enhanced thoracic protection from ballistic protective body armor likely plays a role in the occurrence of blast TBI by preventing lung injuries at blast intensities that could cause TBI. Principal areas of uncertainty include the need for a more comprehensive injury assessment for mild blast injuries in humans, an improved understanding of blast TBI pathophysiology of blast TBI in animal models and humans, the relationship between clinical manifestations of PTSD and mild TBI from blunt or blast trauma including possible synergistic effects, and scaling between animals models and human exposure to blasts in wartime and terrorist attacks. Experimental methodologies, including location of the animal model relative to the shock or blast source, should be carefully designed to provide a realistic blast experiment with conditions comparable to blasts on humans. If traditional blast scaling is appropriate between species, many reported rodent blast TBI experiments using air shock tubes have blast overpressure conditions that are similar to human long-duration nuclear blasts, not high explosive blasts. PMID:22012085

Bass, Cameron R; Panzer, Matthew B; Rafaels, Karen A; Wood, Garrett; Shridharani, Jay; Capehart, Bruce

2011-10-20

74

Greenland Inland Traverse (GrIT): 2010 Mobility Performance and Implications.  

National Technical Information Service (NTIS)

The National Science Foundation initiated the Greenland Inland Traverse (GrIT) to resupply science stations at NEEM and Summit via over-snow transport. The inaugural traverse in 2008, while successful, encountered mobility problems owing to steep slopes a...

J. H. Lever

2011-01-01

75

Optimal Blast Condition for the Inner Surface of Mass Produced NAS Battery Cylindrical Aluminum Cell Containers as Pretreatment of Thermal Spraying  

NASA Astrophysics Data System (ADS)

The relationship between roughness caused by blasting and adhesion of spray coatings on aluminum container substrates was studied through various experiments as part of measures for improving the adhesion of the 75mass%Cr-Fe alloy plasma spray coating for sulfi dation corrosion resistance, which is applied on the inner surface of cylindrical Al containers of high-temperature type NAS batteries. Surface roughness of ?mRa2.8 - 7.3 was acquired by using Al2O3 particle size #100 (212 - 75?m) to #46 (600 - 250?m) grit. In order to achieve uniform roughness and a clean surface, a combination of blasting when the nozzle was being inserted from the top of the container, and air blowing when the nozzle was being removed was done. It was determined that when Al2O3 particles of size #100 grit was used, a good anchoring shape was formed throughout with a roughened surface of ?mRa 2.8. When the internal surface of 3000 Al cylindrical containers were continually blasted using particle size #100 grit, the initial surface roughness of ?mRa3.7 - 3.9 only deteriorated to about ?mRa2.6. A 75mass%Cr-Fe alloy spray coating was applied to the Al cylindrical containers that were roughened using particle size #100 grit. This coating showed cracks by a bending test, but no peeling occurred. This coating was examined by a tensile strength test and showed good adhesion at 64 - 66 MPa. Through experiments, it was proven that spray coatings formed on the Al cylindrical containers after receiving optimal blasting with particle size #100 grit had good adhesion and corrosion resistance after being used for NAS batteries that stored electrical power for about nine years.

Ando, Takashi; Harada, Yoshio

76

Use of grit supplements by waterbirds: an experimental assessment of strategies to reduce lead poisoning  

Microsoft Academic Search

The ingestion of spent Pb shot due to confusion with grit or inadvertently with food particles causes Pb poisoning in a large\\u000a number of waterbirds, this being one of the main causes of mortality for some species. Lead ammunition for hunting is being\\u000a progressively banned in more countries, while grit supplementation has been proposed as a management measure to reduce

Monica Martinez-Haro; Andy J. Green; Pelayo Acevedo; Rafael Mateo

2011-01-01

77

Properties and Performance of the Balloon-Borne Compton Telescope LXeGRIT  

Microsoft Academic Search

The balloon-borne LXeGRIT is the first prototype of a novel Compton telescope based on a high resolution 3-D imaging time projection chamber (TPC). Filled with high purity liquid Xenon, the LXeGRIT TPC has an active volume of 400 cm^2 × 7 cm, implemented with 128 electronic channels for X-Y position readout and total energy measurement and with 4 VUV PMTs

Elena Aprile; Alessandro Curioni; Karl-Ludwig Giboni; Masanori Kobayashi; Jamilla Hussain; Uwe Oberlack; Tadayoshi Doke; Jun Kikuchi; Edward L. Chupp; Philip P. Dunphy; Sandro Ventura

2002-01-01

78

High speed abrasive belt grinding  

NASA Astrophysics Data System (ADS)

A project was established to reduce current stock removal costs and eliminate finish turning operations of tubes by combining rough stock removal and finish grinding. The first phase was designated for engineering and investigation into the feasibility and application of abrasive belt grinding technology. This information was then used to generate a specification establishing some criteria for design and manufacture of a machine to remove heavy stock and finish tubes using abrasive belt technology. The specification was subsequently used for the acquisition of a machine to perform the tasks. The second phase was designated for testing of the equipment and establishing production parameters.

Bak, Joseph

1989-01-01

79

Hard Rock Cutting with Abrasion Jet.  

National Technical Information Service (NTIS)

The usefulness of high-pressure waterjets in cutting hard materials such as concrete, rock, and minerals was significantly improved by entraining selective abrasives into the waterjet. In fact, good entrainment of abrasives into the waterjet was found to ...

G. G. Yie

1983-01-01

80

Mass flow rate measurement in abrasive jets using acoustic emission  

NASA Astrophysics Data System (ADS)

The repeatability of abrasive jet machining operations is presently limited by fluctuations in the mass flow rate due to powder compaction, stratification and humidity effects. It was found that the abrasive mass flow rate for a typical abrasive jet micromachining setup could be determined by using data from the acoustic emission of the abrasive jet impacting a flat plate. Two methods for extracting the mass flow rate from the acoustic emission were developed and compared. In the first method, the number of particle impacts per unit time was determined by a direct count of peaks in the acoustic emission signal. The second method utilizes the power spectrum density of the acoustic emission in a specific frequency range. Both measures were found to correlate strongly with the mass flow rate measured by weighing samples of blasted powder for controlled time periods. It was found that the peak count method permits measurement of the average frequency of the impacts and the mass flow rate, but can only be applied to flow rates in which the impact frequency is approximately one order of magnitude less than the frequency of the target plate ringing. The power spectrum density method of signal processing is applicable to relatively fine powders and to flow rates at which the average impact frequency is of the same order of magnitude as that of the ringing due to the impact. The acoustic emission technique can be used to monitor particle flow variations over a wide range of time periods and provides a straightforward and accurate means of process control.

Ivantsiv, V.; Spelt, J. K.; Papini, M.

2009-09-01

81

Geometric Modeling of Engineered Abrasive Processes  

Microsoft Academic Search

One of the common issues that arises in abrasive machining is the inconsistency of the surface roughness within the same batch and under identical machining conditions. Recent advances in engineered abrasives have allowed replacement of the random arrangement of minerals on conventional belts with precisely shaped structures uniformly cast directly onto a backing material. This allows for abrasive belts that

Andres L. Carrano; James B. Taylor

2005-01-01

82

Clarification of magnetic abrasive finishing mechanism  

Microsoft Academic Search

In order to clarify the mechanism of magnetic abrasive polishing, a planar type process for a non-magnetic material, stainless steel, was examined. A magnetic abrasive brush was formed between a magnetic pole and a workpiece material, in which the summation of three kinds of energy necessary for magnetization of abrasives, i.e. repulsion between bundles (Faraday effect) and line tension of

T Mori; K Hirota; Y Kawashima

2003-01-01

83

Claw Abrasives in Layer Cages - A Review  

Microsoft Academic Search

A review was undertaken to obtain information on the range of claw abrasives which could be used in layer cages to keep claws of hens blunt. In Europe a council directive has been issued which requires that all layer cages be fitted with suitable claw shortening devices. Research in Europe on claw abrasives suggest that abrasives reduce claw length of

P. C. Glatz

2002-01-01

84

Four variables affecting magnitude of dentrifice abrasiveness.  

PubMed

A five-factor study was done on human dentin abrasion that involved two abrasives, either alone or in dentifrice form, two brush brands, two brush hardnesses, two concentrations, and two temperatures of testing. The hard brushes caused 3.6 times as much wear as the soft brushes, a greater influence than the abrasives compared. A brush X hardness interaction indicated that there is a wide variation among the stiffness gradings of toothbrushes. Tests run at 37 C were 28% less abrasive than those at room temperature, suggesting a softening of bristles because of the warmer temperature. A highly significant abrasive X concentration interaction showed that dentifrices became more than twice as abrasive on dilution form 100 to 50%, but that abrasives alone did not show such changes on dilution. The second study included two hardnesses, two abrasives, three diluents, four concentrations, and two replicates. An interaction was found between abrasive and diluent, showing that glycerine inhibited abrasion by 88% in comparison with saliva and CMC. A hardness X concentration interaction showed that wear varied widely with concentration for the hard brush but scarcely at all for the soft brush. These findings suggest that abrasiveness of dentifrices depends strongly on testing conditions and that no single set of conditions is suitable for evaluating dentifrice abrasiveness. PMID:178706

Harte, D B; Manly, R S

85

Abrasive swivel assembly and method  

DOEpatents

An abrasive swivel assembly for providing a rotating, particle-laden fluid stream and, ultimately, a rotating particle-laden fluid jet is disclosed herein. This assembly includes a tubular arrangement for providing a particle-free stream of fluid, means for rotating a section of the tubular arrangement, and means for introducing solid particles into the particle-free fluid stream at a point along the rotating tubular section, whereby to produce a particle-laden fluid stream. This last-mentioned stream can then be used in combination with a cooperating nozzle arrangement for providing a rotating particle-laden fluid jet. In an actual working embodiment, the fluid stream is of sufficiently high pressure so that the abrasive jet can be used as a cutting jet.

Hashish, Mohamed (Kent, WA); Marvin, Mark (Tacoma, WA)

1989-01-01

86

Blast furnace stove control  

SciTech Connect

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.

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

87

Blast injury research models  

PubMed Central

Blast injuries are an increasing problem in both military and civilian practice. Primary blast injury to the lungs (blast lung) is found in a clinically significant proportion of casualties from explosions even in an open environment, and in a high proportion of severely injured casualties following explosions in confined spaces. Blast casualties also commonly suffer secondary and tertiary blast injuries resulting in significant blood loss. The presence of hypoxaemia owing to blast lung complicates the process of fluid resuscitation. Consequently, prolonged hypotensive resuscitation was found to be incompatible with survival after combined blast lung and haemorrhage. This article describes studies addressing new forward resuscitation strategies involving a hybrid blood pressure profile (initially hypotensive followed later by normotensive resuscitation) and the use of supplemental oxygen to increase survival and reduce physiological deterioration during prolonged resuscitation. Surprisingly, hypertonic saline dextran was found to be inferior to normal saline after combined blast injury and haemorrhage. New strategies have therefore been developed to address the needs of blast-injured casualties and are likely to be particularly useful under circumstances of enforced delayed evacuation to surgical care.

Kirkman, E.; Watts, S.; Cooper, G.

2011-01-01

88

Carbon and carbon-containing refractory materials for blast-furnaces at the Chelyabinsk Electrode Plant Joint-Stock Co  

Microsoft Academic Search

The effect of SiC additives and the granular composition on porosity, abrasive resistance, and endurance of carbon refractory blocks used in the blast-furnace steel-making technology. The use of microporous refractory blocks makes it possible to extend the blast-furnace production campaign by several years. The high efficiency of low heat-conducting cold-rammed mixes and a carbon-containing concentrate (available from ChEP JSC) is

S. A. Podkopaev; L. N. Ruzhevskaya; I. V. Rybyanets

2004-01-01

89

Blast furnace reactions  

Microsoft Academic Search

Vast a dvances h ave b een m ade in blast-furnace t echnology d uring t he p ast two decades through p lant t rials and plant d evelopments a ssisted by research to provide b etter u nderstanding of physical and chemical w orkings of the blast f urnace. T he f ields of research have i ncluded

E. T. Turkdogan

1978-01-01

90

Improvement of Local Surface Quality by Using Single Abrasive Abrasion Process  

Microsoft Academic Search

AFM-based wear process actually is single abrasive abrasion process. It is widely employed in the surface micro\\/nano machining\\u000a for fabrication of structures at the nanometer scale exhibiting high removing ability of nanometer scale materials. In this\\u000a study, application of AFM-based single abrasive abrasion process in the local surface quality (surface roughness) improvement\\u000a was studied. Merged holes were fabricated using an

Yongda Yan; Tao Sun; Shen Dong

2007-01-01

91

Blast wave energy diagnostic  

NASA Astrophysics Data System (ADS)

The distance radiation waves that supersonically propagate in optically thick, diffusive media are energy sensitive. A blast wave can form in a material when the initially diffusive, supersonic radiation wave becomes transonic. Under specific conditions, the blast wave is visible with radiography as a density perturbation. [Peterson et al., Phys. Plasmas 13, 056901 (2006)] showed that the time-integrated drive energy can be measured using blast wave positions with uncertainties less than 10% at the Z Facility. In some cases, direct measurements of energy loss through diagnostic holes are not possible with bolometric and x-ray radiometric diagnostics. Thus, radiography of high compression blast waves can serve as a complementary technique that provides time-integrated energy loss through apertures. In this paper, we use blast waves to characterize the energy emerging through a 2.4 mm aperture and show experimental results in comparison to simulations.

Tierney, Thomas E.; Tierney, Heidi E.; Idzorek, George C.; Watt, Robert G.; Peterson, Robert R.; Peterson, Darrell L.; Fryer, Christopher L.; Lopez, Mike R.; Jones, Michael C.; Sinars, Daniel; Rochau, Gregory A.; Bailey, James E.

2008-10-01

92

Ultrasonic assisted magnetic abrasive finishing of hardened AISI 52100 steel using unbonded SiC abrasives  

Microsoft Academic Search

Ultrasonic assisted magnetic abrasive finishing (UAMAF) integrates the use of ultrasonic vibrations and magnetic abrasive finishing (MAF) process to finish surfaces to nanometer order in a relatively short time. The present study emphasizes on the fabrication of UAMAF setup. Using this experimental setup, experimental studies have been carried out with respect to five important process parameters namely supply voltage, abrasive

Rahul S. Mulik; Pulak M. Pandey

2011-01-01

93

Mobility and Economic Feasibility of the Greenland Inland Traverse (GrIT).  

National Technical Information Service (NTIS)

The mobility and economic feasibility of resupplying Summit Camp on the Greenland ice cap from Thule AFB via a 1410-mile (round trip) overland traverse was examined following safe and successful implementation of the Greenland Inland Traverse (GrIT) proof...

J. C. Weale J. H. Lever

2011-01-01

94

Chemical and Toxicological Fate of Fumonisin B1 during Extrusion Processing of Corn Grits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two batches of flaking corn grits were prepared by growing Fusarium verticillioides to contain low and high levels of fumonisin B1 (FB1), Batch-1 at 9.7 ppm and Batch-2 at 50 ppm FB1 as determined by HPLC. These two batches were extruded (Batch-1E; Batch-2E) or extruded with 10% w/w glucose supplem...

95

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

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 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...

2009-01-01

96

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

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

97

BLAST+: architecture and applications  

PubMed Central

Background Sequence similarity searching is a very important bioinformatics task. While Basic Local Alignment Search Tool (BLAST) outperforms exact methods through its use of heuristics, the speed of the current BLAST software is suboptimal for very long queries or database sequences. There are also some shortcomings in the user-interface of the current command-line applications. Results We describe features and improvements of rewritten BLAST software and introduce new command-line applications. Long query sequences are broken into chunks for processing, in some cases leading to dramatically shorter run times. For long database sequences, it is possible to retrieve only the relevant parts of the sequence, reducing CPU time and memory usage for searches of short queries against databases of contigs or chromosomes. The program can now retrieve masking information for database sequences from the BLAST databases. A new modular software library can now access subject sequence data from arbitrary data sources. We introduce several new features, including strategy files that allow a user to save and reuse their favorite set of options. The strategy files can be uploaded to and downloaded from the NCBI BLAST web site. Conclusion The new BLAST command-line applications, compared to the current BLAST tools, demonstrate substantial speed improvements for long queries as well as chromosome length database sequences. We have also improved the user interface of the command-line applications.

2009-01-01

98

Passive blast pressure sensor  

DOEpatents

A passive blast pressure sensor for detecting blast overpressures of at least a predetermined minimum threshold pressure. The blast pressure sensor includes a piston-cylinder arrangement with one end of the piston having a detection surface exposed to a blast event monitored medium through one end of the cylinder and the other end of the piston having a striker surface positioned to impact a contact stress sensitive film that is positioned against a strike surface of a rigid body, such as a backing plate. The contact stress sensitive film is of a type which changes color in response to at least a predetermined minimum contact stress which is defined as a product of the predetermined minimum threshold pressure and an amplification factor of the piston. In this manner, a color change in the film arising from impact of the piston accelerated by a blast event provides visual indication that a blast overpressure encountered from the blast event was not less than the predetermined minimum threshold pressure.

King, Michael J.; Sanchez, Roberto J.; Moss, William C.

2013-03-19

99

Abrasion by Aeolian Particles: Earth and Mars.  

National Technical Information Service (NTIS)

Estimation of the rate of aeolian abrasion of rocks on Mars requires knowledge of: (1) particle flux, (2) susceptibilities to abrasion of various rocks, and (3) wind frequencies on Mars. Fluxes and susceptibilities for a wide range of conditions were obta...

R. Greeley S. Williams B. R. White J. Pollack J. Marshall

1984-01-01

100

Ceramic-bonded abrasive grinding tools  

DOEpatents

Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

Holcombe, Jr., Cressie E. (Farragut, TN); Gorin, Andrew H. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN)

1994-01-01

101

ECM-abrasive polishing of metals  

Microsoft Academic Search

The combined action of abrasives and electrochemical machining (ECM) results in a better surface finish than that could be achieved by using abrasives alone. From an initial roughness of Rtm 30 to 50 nm, flat carbon steel and stainless steel specimens could be finished to a roughness of Rtm 0-4 ?m. The procedures in conducting the experiments and analysing the

S. C. TAM; N. H. LOH; S. MIYAZAWA

1989-01-01

102

Abrasive flow machining of turbine engine components  

Microsoft Academic Search

A technique used for improving the performance and durability of aircraft turbine engines by flowing abrasive media through critical components is described. The process is abrasive only where the flow is restricted: the extrusion area (the process is also known as extrusion honing). Process parameters including extrusion pressure and the volume of flow are presented, and the tooling and media

Rhoades

1990-01-01

103

Surface evolution models in abrasive jet micromachining  

Microsoft Academic Search

The paper presents model predictions and experimental data related to the abrasive jet micromachining of masked and unmasked channels in glass. The spatial and velocity distributions of particles in the jet of an abrasive jet micromachining (AJM) setup were measured using a novel technique. It was found that the velocity decreased linearly from the centerline of the jet to the

A. Ghobeity; T. Krajac; T. Burzynski; M. Papini; J. K. Spelt

2008-01-01

104

Selected problems of abrasive hybrid machining  

Microsoft Academic Search

Advanced manufacturing processes are increasingly hybridized with other conventional and nontraditional machining processes to create entirely new techniques with superior manufacturing and control capabilities. The study reported in this paper explores some of the fundamental processes, which occur during abrasive electrochemical machining (AECM, AECG, ECH) and abrasive electrical discharge machining (AEDM, AEDG).

Jerzy Kozak; Kazimierz E Oczo?

2001-01-01

105

Parametric study of magnetic abrasive finishing process  

Microsoft Academic Search

In the present investigation on magnetic abrasive finishing (MAF) process, Taguchi design of experiments is applied to find out important parameters influencing the surface quality generated. Important parameters influencing the surface quality generated during the MAF are identified as: (i) voltage (DC) applied to the electromagnet, (ii) working gap, (iii) rotational speed of the magnet, and (iv) abrasive size (mesh

Dhirendra K. Singh; V. K. Jain; V. Raghuram

2004-01-01

106

Ceramic-bonded abrasive grinding tools  

DOEpatents

Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

Holcombe, C.E. Jr.; Gorin, A.H.; Seals, R.D.

1994-11-22

107

Bound-abrasive polishers for optical glass.  

PubMed

Polishing abrasives that have been bound in a solid matrix can offer several potential advantages over loose-abrasive processes with pitch or polyurethane laps for finishing of optics. These advantages include polishing efficiency, temperature stability, cost of consumables, and compatibility with computer numerically controlled generating machines. Unfortunately, little has been published on bound-abrasive polishers, and very few commercially available products exist. We have developed several compositions and manufacturing techniques that show promise for polishing a variety of optical glasses. We establish the various criteria for a successful bound-abrasive polisher. The numerous variables to be considered in designing these polishers are identified, and the results of screening experiments are used to find successful compositions. Polishing experiments with bound abrasives in arrays of pellets, as ring tools, and as full-contact laps are described. PMID:18273316

Gillman, B E; Jacobs, S D

1998-06-01

108

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

NASA Astrophysics Data System (ADS)

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.

Arifvianto, Budi; Suyitno; Mahardika, Muslim

2013-08-01

109

ESF BLAST DESIGN ANALYSIS  

SciTech Connect

The purpose and objective of this design analysis are to develop controls considered necessary and sufficient to implement the requirements for the controlled drilling and blasting excavation of operations support alcoves and test support alcoves in the Exploratory Studies Facility (ESF). The conclusions reached in this analysis will flow down into a construction specification ensuring controlled drilling and blasting excavation will be performed within the bounds established here.

E.F. fitch

1995-03-13

110

Computer cast blast modelling  

SciTech Connect

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 normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC, applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the DMC can perform a blast simulation in 0.5 hours on the SUN SPARCstation 10--41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC computer. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.

Chung, S. [ICI Explosives Canada, North York, ON (Canada); McGill, M. [ICI Explosives USA, Dallas, TX (United States); Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States)

1994-07-01

111

Plastic media blasting activities at Hill Air Force Base  

NASA Astrophysics Data System (ADS)

Hill Air Force Base in Utah developed plastic media blasting (PMB) paint removal process for removing paint from Air Force aircraft. The development of the process involved extensive testing of various abrasives and subsequent parameters to end up with an approved production process. Hill AFB has been using PMB in a production mode since 1985, and completely discontinued chemical stripping of airframes in 1989. We have recently installed and began operating a fully automated PMB facility that utilizes two nine-axis robots to strip an aircraft. This system has enabled us to further reduce the manhours required to strip an aircraft, and also allowed us to remove the employee from the blasting atmosphere into a control room. We have, and will continue to realize, significant environmental and economic savings by using PMB. Hill is also actively involved with the development of future paint stripping technologies.

Christensen, J. D.

1993-03-01

112

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

SciTech Connect

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.

Kroll, Peter; Kane, Sally Minch [eds.

1982-04-01

113

Blast lung: experience at CIMS.  

PubMed

Blast lung is a clinical condition which is characterised by respiratory difficulty and hypoxia without obvious external injury to the chest in bomb blast cases. Two patients of the bomb blast episode were brought at emergency department at Chhattisgarh Institute of Medical Sciences, Bilaspur in a state of shock. After proper wound care, resuscitation and investigation both the cases proved to be that of blast lung. In bomb blast cases although there might not be any external injury over chest wall, it will be sensible to rule out blast lung in all cases with the help of computerised tomography. PMID:23029850

Singh, Archana; Deshkar, A M; Kashyap, B K; Choudhary, K N; Naik, S K; Tembhurnikar, P S; Singh, B P

2012-02-01

114

The abrasion and impact-abrasion behavior of austempered ductile irons  

SciTech Connect

Austempering of ductile irons has led to a new class of irons, Austempered Ductile Irons (ADIs), with improved mechanical strength and fracture toughness lacking in gray cast irons. Laboratory wear tests have been used to evaluate the abrasive and impact-abrasive wear behavior of a suite of ADIs. The use of high-stress, two-body abrasion, low-stress, three-body abrasion, and impact-abrasion tests provides a clear picture of the abrasive wear behavior of the ADIs and the mechanisms of material removal. When combined with hardness measurements, fracture toughness and a knowledge of the microstructure of the ADIs, the overall performance can be assessed relative to more wear resistant materials such as martensitic steels and high-chromium white cast irons

Hawk, Jeffrey A.; Dogan, Omer N.; Lerner, Y.S. (University of Northern Iowa)

1998-01-01

115

Design and simulation for mico-hole abrasive flow machining  

Microsoft Academic Search

Abrasive flow machining technology has become an effective way for micro-hole precise machining. In this paper, we design an equipment for abrasive flow machining to achieve precise machining for peculiar parts. The Fluent, fluid dynamics software, is used here to simulate the abrasive flow micro-hole processing state. We can achieve an ideal machining program for abrasive flow through comparative analysis

Junye Li; Weina Liu; Lifeng Yang; Chun Li; Bin Liu; Haihong Wu; Xiaoli Sun

2009-01-01

116

Spectroscopy and Imaging Performance of the Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)  

Microsoft Academic Search

LXeGRIT is a balloon-borne Compton telescope based on a liquid xenon time projection chamber (LXeTPC) for imaging cosmic gamma -rays in the energy band 0.2- 20 MeV. The detector, with 400 cm2 area and 7 cm drift gap, is filled with high purity LXe. Both ionization and scintillation light signals are detected to measure the energy deposits and the three

E. Aprile; V. Egorov; K.-L. Giboni; U. G. Oberlack; J. Kikuchi; K. Takizawa; P. P. Dunphy

2000-01-01

117

In-flight Performance of the Balloon Borne LXeGRIT Compton Telescope  

Microsoft Academic Search

The balloon-borne LXeGRIT is the first prototype of a novel Compton telescope based on a high resolution 3-D imaging time projection chamber (TPC). The ionization detector, triggered by the fast Xe scintillation light, measures the three spatial coordinates and the energy deposited by each gamma-ray interaction in its active volume of 2800 cm3 of pure liquid Xenon. As a calorimeter,

Elena Aprile; Alessandro Curioni; Karl-Ludwig Giboni; Masanori Kobayashi; Uwe Oberlack; Edward L. Chupp; Philip P. Dunphy; Sandro Ventura; Tadayoshi Doke; Jun Kikuchi

2003-01-01

118

Liquid xenon gamma-ray imaging telescope (LXeGRIT) for medium energy astrophysics  

Microsoft Academic Search

As part of our ongoing research program to develop a liquid xenon gamma-ray imaging telescope (LXe-GRIT) for medium energy astrophysics, we have built a liquid xenon time projection chamber (LXeTPC) with a total volume of 10 liters and a sensitive are of 20 cm by 20 cm. The detector has been successfully tested with gamma-ray sources in the laboratory and

Elena Aprile; Valeri Egorov; Fang Xu; Edward L. Chupp; Philip Dunphy; Tadayoshi Doke; Jun Kikuchi; Gerald J. Fishman; Geoffrey N. Pendleton; Kimiaki Masuda; Toshisuke Kashiwagi

1996-01-01

119

Effect of addition of grit made of crude and expanded amaranth seeds on the quality of canned meat.  

PubMed

Grit made of crude and expanded amaranth seeds was added to meat-fat batter in order to determine its effect on its quality. Amaranthus cruentus seeds were expanded by the nonpressure method and graded by density (degree of expansion) into three fractions: 341, 208 and 135 kg/m3; crude seed density was 800 kg/m3. Then the seeds were ground to a homogeneous mass with granulation of 0.8 mm. The water-holding capacity and viscosity of grit made of crude and expanded seeds were determined. Class II pork was used for the production of meat-fat batter. Cooking losses were determined in model meat-fat batter, pasteurized and sterilized cans. The texture and color parameters of canned meat were also determined, and a taste-panel evaluation was made. It was found that expanded seed grit was characterized by worse hydration and gelling properties than crude seed grit. Grit made of crude amaranth seeds had a positive effect on the water-holding capacity of stuffing and allowed to reduce the cooking losses in cans. Better water-holding capacity resulted in an improvement in the tenderness, juiciness and taste of canned meat. Its quality deteriorated when large amounts of highly-expanded seed grit were used. PMID:12224423

Ostoja, H; Cierach, M; Konopko, H; Majewska, K

2002-08-01

120

New iron-based SiC spherical composite magnetic abrasive for magnetic abrasive finishing  

NASA Astrophysics Data System (ADS)

SiC magnetic abrasive is used to polish surfaces of precise, complex parts which are hard, brittle and highly corrosion-resistant in magnetic abrasive finishing(MAF). Various techniques are employed to produce this magnetic abrasive, but few can meet production demands because they are usually time-consuming, complex with high cost, and the magnetic abrasives made by these techniques have irregular shape and low bonding strength that result in low processing efficiency and shorter service life. Therefore, an attempt is made by combining gas atomization and rapid solidification to fabricate a new iron-based SiC spherical composite magnetic abrasive. The experimental system to prepare this new magnetic abrasive is constructed according to the characteristics of gas atomization and rapid solidification process and the performance requirements of magnetic abrasive. The new iron-based SiC spherical composite magnetic abrasive is prepared successfully when the machining parameters and the composition proportion of the raw materials are controlled properly. Its morphology, microstructure, phase composition are characterized by scanning electron microscope(SEM) and X-ray diffraction(XRD) analysis. The MAF tests on plate of mold steel S136 are carried out without grinding lubricant to assess the finishing performance and service life of this new SiC magnetic abrasive. The surface roughness( R a) of the plate worked is rapidly reduced to 0.051 ?m from an initial value of 0.372 ?m within 5 min. The MAF test is carried on to find that the service life of this new SiC magnetic abrasive reaches to 155 min. The results indicate that this process presented is feasible to prepare the new SiC magnetic abrasive; and compared with previous magnetic abrasives, the new SiC spherical composite magnetic abrasive has excellent finishing performance, high processing efficiency and longer service life. The presented method to fabricate magnetic abrasive through gas atomization and rapid solidification presented can significantly improve the finishing performance and service life of magnetic abrasive, and provide a more practical approach for large-scale industrial production of magnetic abrasive.

Zhang, Guixiang; Zhao, Yugang; Zhao, Dongbiao; Zuo, Dunwen; Yin, Fengshi

2013-03-01

121

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

SciTech Connect

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.

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

2003-10-01

122

Abrasive-Waterjet Machining of Isogrid Structures.  

National Technical Information Service (NTIS)

An experimental investigation was conducted to determine the feasibility of machining isogrid structures with abrasive-waterjets (AWJs). The main objective was to mill isogrid patterns in surfaces with accurate depth control using an AWJ. Three different ...

M. Hashish M. Marvin D. Monserud

1990-01-01

123

Abrasive flow machining of turbine engine components  

SciTech Connect

A technique used for improving the performance and durability of aircraft turbine engines by flowing abrasive media through critical components is described. The process is abrasive only where the flow is restricted: the extrusion area (the process is also known as extrusion honing). Process parameters including extrusion pressure and the volume of flow are presented, and the tooling and media are covered. The abrasive grains are mostly made of silicon carbide, although boron carbide, aluminum oxide, and diamond may also be used. Some abrasive-flow machining applications in aerospace involve removal of the thermal recast layer in the lasered cooling holes of blades and disks, deburring fuel spray nozzles, and polishing cast surfaces of blades, compressor wheels, and impellers. 6 refs.

Rhoades, L.J. (Extrude Hone Corp., Irwin, PA (USA))

1990-01-01

124

Winter Operations-Abrasives and Salt Brine.  

National Technical Information Service (NTIS)

The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road sur...

G. Pesti Y. Liu

2003-01-01

125

Blast Furnace Operation with Oxygen-Enriched Unheated Blast Air.  

National Technical Information Service (NTIS)

Three trials with oxygen-enriched unheated blast air are described. The trials were conducted in the Bureau of Mines experimental blast furnace located in Bruceton, PA. For the first trial, moisture was added to the oxygenated blast. The second and third ...

P. L. Woolf

1985-01-01

126

Experimental investigations into abrasive flow machining (AFM)  

Microsoft Academic Search

A new non-traditional finishing process known as abrasive flow machining (AFM) is used to deburr, radius, polish and remove recast layer of components in a wide range of applications. The process is relatively new, although around 2000 machines are in use worldwide. Material is removed from the workpiece by flowing a semisolid visco-elastic\\/visco-plastic abrasive-laden medium across the surface to be

V. K. Jain; S. G. Adsul

2000-01-01

127

Blast Noise Standards and Instrumentation.  

National Technical Information Service (NTIS)

A survey of noise from quarry production blasting was conducted at seven crushed-stone quarries, providing information on close-in noise generation, comparative instrumentation, and evaluation of the sound levels as related to blasting parameters and exis...

D. E. Siskind C. R. Summers

1974-01-01

128

Advances in abrasive technology--prophylaxis pastes.  

PubMed

A newly developed prophylaxis paste that contains perlite as an abrasive medium was compared to conventional prophylaxis pastes with regard to relative dentin and enamel abrasion, cleaning ability, and polishing power. Rubber cups and nylon brushes were used as paste carriers. Water, flour of pumice, and a dentin polishing paste served as controls. The Prophylaxis Paste Index was created to assess the clinical potential of the various prophylaxis pastes more accurately. The index was computed for dentin as cleaning ability divided by relative dentin abrasion x surface roughness (in Ra) x 10, and for enamel as cleaning ability divided by relative enamel abrasion x surface abrasion (in Ra). On dentin and enamel, the perlite-based prophylaxis paste consistently yielded low relative dentin and enamel abrasion values, a good cleaning ability, and low surface roughness scores with both rubber cups and nylon brushes. Of all tested prophylaxis pastes, the perlite-based prophylaxis paste excelled in the Prophylaxis Paste Index on dentin and enamel and with both rubber cup and nylon brush applications. Therefore, a perlite-containing prophylaxis paste may have broad professional therapeutic indications and may be used universally as a single paste to clean and polish both dentin and enamel. PMID:11887699

Lutz, Felix; Imfeld, Thomas

2002-01-01

129

In vitro biological effects of titanium rough surface obtained by calcium phosphate grid blasting.  

PubMed

Surface roughness modulates the osseointegration of orthopaedic and dental titanium implants. High surface roughness are currently obtained by blasting of titanium implants with silica or aluminium oxide abrasive particles. This process may cause the release of cytotoxic silicium or aluminium ions in the peri-implant tissue. To generate a biocompatible roughened titanium surface, we currently develop an innovative grid-blasting process using biphasic calcium phosphate (BCP) particles. Titanium alloy (Ti6Al4V) discs were either polished, BCP grid-blasted or left as-machined. BCP grid-blasting created an average surface roughness of 1.57 +/- 0.07 microm compared to the original machined surface of 0.58 +/- 0.05 microm. X-ray photoelectron spectroscopy indicated traces of calcium and phosphorus and relatively less aluminium on the BCP grid-blasted surface than on the initial titanium specimen. Scanning electronic microscopy observations and measurement of mitochondrial activity (MTS assay) showed that osteoblastic MC3T3-E1 cells were viable in contact with the BCP grid-blasted titanium surface. In addition, our results indicate that MC3T3-E1 cells expressed ALP activity and conserved their responsiveness to bone morphogenetic protein BMP-2. The overall results clearly indicate that this calcium phosphate grid-blasting technique increases the roughness of titanium implants and provides a non-cytotoxic surface with regard to mouse osteoblasts. PMID:15207462

Citeau, Anthony; Guicheux, Jerome; Vinatier, Claire; Layrolle, Pierre; Nguyen, Thien P; Pilet, Paul; Daculsi, Guy

2005-01-01

130

Management of primary blast injury  

Microsoft Academic Search

Blast waves are produced following the detonation of munitions, the firing of large caliber guns, or from any type of explosion. These blast waves can be powerful enough to injure the individuals exposed to them. This type of injury is called primary blast injury (PBI) and the organs most vulnerable to PBI are the gas-filled organs, namely the ear, the

Gregory J. Argyros

1997-01-01

131

Expanded rock blast modeling capabilities of DMC( )BLAST, including buffer blasting.  

National Technical Information Service (NTIS)

A discrete element computer program named DMC( )BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements that are represented a...

D. S. Preece J. P. Tidman S. H. Chung

1996-01-01

132

Jet Blast Hazards.  

National Technical Information Service (NTIS)

The report encompasses a broad review of hazards directly related to inadvertent use of jet thrust power and its adverse effects on other aircraft, airport-ramp personnel, passengers and airport equipment. These jet-blast hazards are illustrated by a repr...

1972-01-01

133

Factors Affecting Internal Blast  

Microsoft Academic Search

Internal blast refers to explosion effects in confined spaces, which are dominated by the heat output of the explosive. Theoretical temperatures and pressures may not be reached due to heat losses and incomplete gas mixing. Gas mixing can have the largest effect, potentially reducing peak quasi-static pressure by a factor of two due to lack of thermal equilibrium between products

R. H. Granholm; H. W. Sandusky; J. E. Felts

2007-01-01

134

FACTORS AFFECTING INTERNAL BLAST  

Microsoft Academic Search

Internal blast refers to explosion effects in confined spaces, which are dominated by the heat output of the explosive. Theoretical temperatures and pressures may not be reached due to heat losses and incomplete gas mixing. Gas mixing can have the largest effect, potentially reducing peak quasi-static pressure by a factor of two due to lack of thermal equilibrium between products

R. H. Granholm; H. W. Sandusky; J. E. Felts

2007-01-01

135

Explosions and blast injuries  

Microsoft Academic Search

Powerful explosions have the potential to inflict many different types of injuries on victims, some of which may be initially occult. Flying debris and high winds commonly cause conventional blunt and penetrating trauma. Injuries caused by blast pressures alone result from complex interactions on living tissues. Interfaces between tissues of different densities or those between tissues and trapped air result

John M. Wightman; Sheri L. Gladish

2001-01-01

136

Expanded rock blast modeling capabilities of DMC{_}BLAST, including buffer blasting  

SciTech Connect

A discrete element computer program named DMC{_}BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in 2-D. DMC{_}BLAST calculations compare favorably with data from actual bench blasts. The blast modeling capabilities of DMC{_}BLAST have been expanded to include independently dipping geologic layers, top surface, bottom surface and pit floor. The pit can also now be defined using coordinates based on the toe of the bench. A method for modeling decked explosives has been developed which allows accurate treatment of the inert materials (stemming) in the explosive column and approximate treatment of different explosives in the same blasthole. A DMC{_}BLAST user can specify decking through a specific geologic layer with either inert material or a different explosive. Another new feature of DMC{_}BLAST is specification of an uplift angle which is the angle between the normal to the blasthole and a vector defining the direction of explosive loading on particles adjacent to the blasthole. A buffer (choke) blast capability has been added for situations where previously blasted material is adjacent to the free face of the bench preventing any significant lateral motion during the blast.

Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States); Tidman, J.P.; Chung, S.H. [ICI Explosives (Canada)

1996-12-31

137

An investigation into magnetic electrolytic abrasive turning  

NASA Astrophysics Data System (ADS)

The magnetic electrolytic abrasive turning (MEAT) process as a non-traditional machining is used to obtain surface finishing like mirror. MEAT provides one of the best alternatives for producing complex shapes with good finish in advanced materials used in aircraft and aerospace industries. The improvement of machining accuracy of MEAT continues to be a major challenge for modern industry. MEAT is a hybrid machining which combines two or more processes to remove material. The present research focuses on the development of precision electrochemical turning (ECT) under the effects of magnetic field and abrasives. The effect of magnetic flux density, electrochemical conditions and abrasive parameters on finishing efficiency and surface roughness are investigated. An empirical relationship is deduced.

Mahdy, M. A. M.; Ismaeial, A. L.; Aly, F. F.

2013-07-01

138

PC controlled toothbrush/dentifrice abrasion machine.  

PubMed

A toothbrush/dentifrice abrasion machine was developed to use in dental research laboratory. The mechanism was designed as a hexagonal block driven by two stepping motors which move the mechanism in four directions. In order to control the stepping motors speed, position and direction commands or signals were generated by a software written in C Programming Language and then these commands were applied the stepping motor drives through parallel port of a personal computer. The toothbrush/dentifrice abrasion machine was finally used to measure different longevity of tooth brush. It was experimentally shown that the mechanism can be used for highly accurate position and speed applications. PMID:10321377

Bal, G; Uçta?li, S; Bekiro?lu, E

1999-02-01

139

29 CFR 1910.215 - Abrasive wheel machinery.  

Code of Federal Regulations, 2013 CFR

...SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel... (a) General requirements â(1) Machine guarding. Abrasive wheels shall be used only on machines provided with safety guards as...

2013-07-01

140

21 CFR 872.6010 - Abrasive device and accessories.  

Code of Federal Regulations, 2013 CFR

...accessories. (a) Identification. An abrasive device and accessories is a device constructed of various abrasives, such as diamond chips, that are glued to shellac-based paper. The device is intended to remove excessive restorative materials,...

2013-04-01

141

BLAST BIOLOGY. Technical Progress Report  

Microsoft Academic Search

Experimental data regarding the biologic consequences of exposure to ;\\u000a several environmental variations associated with actual and simulated explosive ;\\u000a detonations were reviewed. Blast biology is discussed relative to primary, ;\\u000a secondary, tentiary, and miscellaneous blast effects as those attributable, ;\\u000a respectively, to variations in environmental pressure, trauma from blast-produced ;\\u000a missiles (both penetrating and nonpenetrating), the consequences of physical

C. S. White; D. R. Richmond

1959-01-01

142

Noetning av Belaeggningssten i Kulkvarn (Abrasion in Laboratory Ball Mill).  

National Technical Information Service (NTIS)

Tests have been made in a laboratory ball mill, manufactured by Centro-Morgardshammar, Sweden, in order to investigate an alternative test method to the Swedish Abrasion Value (a modified B.S. 812 Abrasion Test). Wet abrasion has been carried out in the b...

P. Hoebeda J. Chytla

1985-01-01

143

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...

144

ABRASIVE-BASED NANO-FINISHING TECHNIQUES: AN OVERVIEW  

Microsoft Academic Search

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

V. K. Jain

2008-01-01

145

21 CFR 872.6030 - Oral cavity abrasive polishing agent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Oral cavity abrasive polishing agent...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive...

2013-04-01

146

Modeling and simulation of magnetic abrasive finishing process  

Microsoft Academic Search

Magnetic abrasive finishing (MAF) is one of the advanced finishing processes, which produces a high level of surface quality and is primarily controlled by a magnetic field. In MAF, the workpiece is kept between the two poles of a magnet. The working gap between the workpiece and the magnet is filled with magnetic abrasive particles. A magnetic abrasive flexible brush

S. C. Jayswal; V. K. Jain; P. M. Dixit

2005-01-01

147

Analysis of magnetic abrasive finishing with slotted magnetic pole  

Microsoft Academic Search

Magnetic Abrasive Finishing (MAF) is relatively a new finishing process among the advanced finishing processes in which the workpiece is kept in the magnetic field created by two poles of an electromagnet. The working gap between the workpiece and the magnet is filled with magnetic abrasive particles. A flexible magnetic abrasive brush is formed, acting as a multipoint cutting tool,

S. C. Jayswal; V. K. Jain; P. M. Dixit

2004-01-01

148

29 CFR 1915.134 - Abrasive wheels.  

Code of Federal Regulations, 2010 CFR

...be used. (2) When wheels 2 inches or less in diameter...securely mounted on the end of a steel mandrel are...d) Portable abrasive wheels used for internal grinding...securely mounted on the end of a steel mandrel are used. (2) If the wheel is entirely within...

2009-07-01

149

29 CFR 1915.134 - Abrasive wheels.  

Code of Federal Regulations, 2010 CFR

...be used. (2) When wheels 2 inches or less in diameter...securely mounted on the end of a steel mandrel are...d) Portable abrasive wheels used for internal grinding...securely mounted on the end of a steel mandrel are used. (2) If the wheel is entirely within...

2010-07-01

150

Abrasive wear behaviour of austempered ductile iron  

Microsoft Academic Search

This paper presents a study of the abrasive wear behaviour of austempered ductile irons (ADI’s) with dual matrix structures under different conditions. The wear resistance model was developed based on the type of the material, applied load and sliding distance. The orthogonal array and analysis of variance were employed to find out which design parameters significantly affect the quality characteristic.

Y. Sahin; O. Durak

2007-01-01

151

Cleaning Power and Abrasivity of European Toothpastes  

Microsoft Academic Search

For 41 toothpastes available to European consumers in 1995, the cleaning efficacy was evaluated in comparison with abrasivity on dentin (RDA value). For cleaning power assessment, a modified pellicle cleaning ratio (PCR) measurement method was developed. The method is characterized by a five-day tea-staining procedure on bovine front teeth slabs on a rotating wheel, standardized brushing of the slabs in

P. Wiilknitz

1997-01-01

152

Neural Network Modeling of Abrasive Flow Machining  

Microsoft Academic Search

This paper discusses the preliminary development of a neural network-based process monitor and off-line controller for abrasive flow machining of automotive engine intake manifolds. The process is only observable indirectly, yet the time at which machining achieves the specified air flow rate must be estimated accurately. A neural network model is used to estimate when the process has achieved air

Alice E. Smith; William S. Slaughter

153

Rock Abrasion Tool: Mars Exploration Rover mission  

Microsoft Academic Search

The Rock Abrasion Tool (RAT) is an integral part of the Athena Science payload. Serving primarily as the geologist's rock hammer, the RAT will expose fresh surfaces of Martian rocks to other instruments on the payload. The RAT also brushes dust and debris from an excavated hole or unaltered rocks. To accomplish these tasks autonomously, the RAT, a sophisticated 3-axis

S. P. Gorevan; T. Myrick; K. Davis; J. J. Chau; P. Bartlett; S. Mukherjee; R. Anderson; S. W. Squyres; R. E. Arvidson; M. B. Madsen; P. Bertelsen; W. Goetz; C. S. Binau; L. Richter

2003-01-01

154

Corneal abrasions associated with pepper spray exposure  

Microsoft Academic Search

Pepper spray containing oleoresin capsicum is used by law enforcement and the public as a form of nonlethal deterrent. Stimulated by the identification of a case of a corneal abrasion associated with pepper spray exposure, a descriptive retrospective review of a physician-maintained log of patients presenting to a jail ward emergency area over a 3-year period was performed. The objective

Lance Brown; Darren Takeuchi; Kathryn Challoner

2000-01-01

155

Method of forming a flexible abrasive sheet article  

US Patent & Trademark Office Database

Flexible abrasive sheet articles having precision thickness flat-topped raised island structures that are coated with a monolayer of equal sized abrasive agglomerate are described. Methods of producing high quality equal-sized spherical shaped composite abrasive agglomerate beads containing small diamond abrasive particles are described. Beads are produced by level-filling fine mesh screens or perforated sheets with a water based metal oxide slurry containing abrasive particles and then using a fluid jet to eject the abrasive slurry lumps from the individual screen cells into a dehydrating environment. Surface tension forces form the ejected liquid lumps into spheres that are solidified and then heated in a furnace to form ceramic beads. These porous ceramic abrasive beads can be bonded directly onto the flat planar surface of a flexible backing material or they can be bonded onto raised island surfaces to form rectangular or disk abrasive sheet articles. Abrasive articles having equal sized abrasive beads are particularly suited for lapping and raised island articles are suited for high speed lapping. Non-abrasive equal-sized beads can also be formed using this simple bead manufacturing process, which requires only a very low capital investment.

Duescher; Wayne O. (Roseville, MN)

2013-10-01

156

Blast load assessment using hydrocodes  

Microsoft Academic Search

The evaluation of pressures and impulses produced by blast loads with the aid of hydrocodes is studied in this paper. Numerical results are compared with those obtained with existing analytical expressions for different scaled distances and boundary conditions. In particular, the capacity of both methods to capture multiple reflections of the blast load is analyzed. The effects of mesh size

B. Luccioni; D. Ambrosini; R. Danesi

2006-01-01

157

Blast furnace injection symposium: Proceedings  

SciTech Connect

These proceedings contain 14 papers related to blast furnace injection issues. Topics include coal quality, coal grinding, natural gas injection, stable operation of the blast furnace, oxygen enrichment, coal conveying, and performance at several steel companies. All papers have been processed separately for inclusion on the data base.

NONE

1996-12-31

158

Classification of Dry-Milled Maize Grit Yield Groups Using Quadratic Discriminant Analysis and Decision Tree Algorithm  

Microsoft Academic Search

Cereal Chem. 84(2):152-161 A genetically and environmentally diverse collection of maize (Zea maize L.) samples was 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 (PCA) reduced a set of approximately 500 samples collected from six states to 154 maize hybrids.

Kyung-Min Lee; Timothy J. Herrman; Scott R. Bean; David S. Jackson; Jane Lingenfelser

2007-01-01

159

Centrifugal shot blast system  

SciTech Connect

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.

NONE

1998-02-01

160

A 71-year-old man with anaphylaxis after eating grits.  

PubMed

The allergist is frequently called on to evaluate patients after episodes of anaphylaxis to determine the cause and implement preventive measures that will reduce the patient's risk from future episodes. The etiology of anaphylaxis can be the result of numerous causes that may go undiagnosed if a thorough evaluation is not performed. We present a 71-year-old man with no history of food allergy or atopy who presented to the emergency room and then our allergy clinic for evaluation after suffering anaphylaxis after a meal of grits and shrimp. The underlying diagnosis, which was subsequently determined, requires a high index of suspicion and should be included in the differential diagnosis of any patient presenting with unexplained anaphylaxis. PMID:22370536

Posthumus, Jonathon; Borish, Larry

161

Effectiveness of Power Tool Cleaning as an Alternative to Abrasive Blasting.  

National Technical Information Service (NTIS)

Zone fabrication methods implemented by U.S. shipyards, incorporating block construction and zone outfitting and painting, have increased the need for more productive methods of secondary surface preparation. This 'interim product' oriented ship construct...

J. W. Peart

1995-01-01

162

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

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.

William S. McPhee

1999-05-31

163

Measurement of nanoparticle removal by abrasion  

NASA Astrophysics Data System (ADS)

A strong release limitation of single nanoparticles from commercial manufactured "nanoproducts" is necessary to decrease potential exposure risks of consumers and represents also a pragmatic way to facilitate acceptance for nanomaterial commercialization before obtaining definitive toxicological results. So, it is of prime importance to know how to characterize the release of small materials during usage solicitations such as mechanical, thermal, UV stress: are they single nanoparticles, aggregates or nanoparticles included in a bigger piece of the matrix? In the frame of NanoSafe2 project, CEA developed and qualified a specific bench test where the material to be tested is mechanically solicited by abrasion using a normalized Taber equipment. The first results show that nanofillers can be released in usage by abrasion for non optimised nanoproducts.

Guiot, Arnaud; Golanski, Luana; Tardif, François

2009-05-01

164

Design of an impact abrasion testing machine  

Microsoft Academic Search

By using a cam-flat follower-impact shaft with a crank-flat rotating anvil system, the machine to be described can create various impact abrasion conditions to simulate a large range of industrial situations encountered in this field. The main features of the machine are the long working life of the flat rotating anvil, which works in the same way as that of

D. Zhang; P. R. Beeley; A. J. Baker

1994-01-01

165

Controlled Toothbrush Abrasion of Softened Human Enamel  

Microsoft Academic Search

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

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

2008-01-01

166

A study of abrasion in steel during comminution  

NASA Astrophysics Data System (ADS)

Comminution is a process used in mineral processing for the size reduction of mined material, to permit effective handling, separation and recovery. The equipment used is kinetically complex, with very high-energy impacts and high forces, leading to great amounts of abrasive wear. It is desired to develop a better understanding of these processes, to both measure them and increase comminution while reducing wear. The Steel Wheel Abrasion Test is a laboratory technique used to generate controlled, abrasive three-body wear. By altering the applied force, rotational speed of the wheel and abrasive agent used in the SWAT, the wear behaviour of a material can be quantified. High-stress wear, which occurs when abrasive material is degraded during the test, can replicate the processes occurring in comminution systems. This work has found that abrasive wear will increase with increasing input energy into the tribological interaction. This wear can be linked to the energy input into the system, through the measurement of applied forces, wheel rotational speed and generated torque. This results in the development of a specific abrasion energy, EAS, which provide an energy metric for the abrasion process. Furthermore, the breakage induced in the abrasive particles can also be quantified and evaluated, generating a comminution metric, the specific comminution energy, ECS. These indices can then be linked, to develop an understanding of systems where comminution and abrasion occur concurrently.

Lafleur, Jean-Philippe

167

The abrasive wear of single and multiphase materials  

SciTech Connect

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.

McGee, A.C.

1990-01-01

168

The BLAST experiment  

NASA Astrophysics Data System (ADS)

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.

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

169

[Determination of abrasive properties of toothpastes by means of copper abrasion].  

PubMed

The results are presented of the investigations of the proposed method for determination of the abrasive properties of toothpastes and raw materials used for their production. The method is based on brushing of copper surface with the studied paste in a device of own design, followed by chemical analysis of copper content in the mass after brushing. The optimal parameters of the work of the abrasive device were determined and the method for determination of copper content is described. For chemical analysis absorption spectroscopy in visible light and atomic absorption spectroscopy were used. The advantages of the proposed method of abrasive force determination was discussed comparing them to those of radioisotope assay. PMID:2104375

Kosta?ski, M; Magas, S; Górski, Z; Mendyk, W

1990-08-01

170

Simulation for the prediction of surface roughness in magnetic abrasive flow finishing (MAFF)  

Microsoft Academic Search

The final machining (or finishing) of precision parts with high level of surface finish and close tolerance is making the application of magnetic abrasive finishing technology increasingly important. Magnetic abrasive flow finishing (MAFF) is a new abrasive finishing process combining the features of abrasive flow finishing (AFF) and magnetic abrasive finishing (MAF). MAFF provides a high level of surface finish

Amit M. Wani; Vinod Yadava; Atul Khatri

2007-01-01

171

Blast-Induced Translational Effects.  

National Technical Information Service (NTIS)

A mathematical model was developed to predict the time displacement histories of objects translated by the blast winds from conventional or nuclear explosions; these predictions were then compared to actual experiments. The objects studied varied in size ...

E. R. Fletcher I. G. Bowen

1966-01-01

172

Predicting three-body abrasive wear using Monte Carlo methods  

Microsoft Academic Search

Predicting wear of materials under three-body abrasion is a challenging project, since three-body abrasion is more complicated than two-body abrasion. In this paper, a Monte Carlo model for simulating plastic deformation wear rate, i.e. low-cycle fatigue wear rate, is proposed. The Manson–Coffin formula and the Palmgrom–Miner linear accumulated-damage principle were used in the model as well as the Monte Carlo

Liang Fang; Weimin Liu; Daoshan Du; Xiaofeng Zhang; Qunji Xue

2004-01-01

173

An abrasion algorithm for projectile mass loss during penetration  

Microsoft Academic Search

A finite-element algorithm is presented for the computation of projectile mass loss due to abrasion at a projectile\\/target interface. The algorithm includes an abrasion-rate model applied to the surface nodes of the projectile, an adjustment of nodal masses, an adjustment of element volumes, and fully automatic rezoning of the projectile as required. Calibration of the abrasion-rate model is followed by

Stephen R Beissel; Gordon R Johnson

2000-01-01

174

Global primary blast injury: a rat model.  

PubMed

Blast wave injury from bombs cause a unique but poorly understood spectrum of injuries. Previous blast wave models involved high energy explosives detonated in an open field without the sophisticated monitoring of laboratory equipment. We characterized a rodent model that produces a global blast injury in a safe laboratory environment. Male rats, prospectively randomized to four groups of ten, were anesthetized and subjected to a blast at 2.0 cm, 2.5 cm, or 3.5 cm from the blast nozzle. The control group received no blast. Intensity of the blast (80-120 psi peak pressure, 1-2 msec duration) was controlled by varying the distance of the blast wave generator to the rat. The rats were monitored for three hours following the blast and then euthanized. Bradycardia was an immediate but transient response to blast injury. Mean arterial pressure was bimodal with severe hypotension occurring immediately after the blast and, again, two to three hours later. The characteristic injuries from a blast wave, such as pulmonary hemorrhage with increased lung weight, intestinal serosal hemorrhage, and hemoperitoneum, were found in the rats subjected to the blast pressure wave. In conclusion, our rodent model accurately reproduces the clinical spectrum of injuries seen in blast victims and will provide a powerful tool for studying the pathophysiology and potential treatments of bomb blast victims. PMID:9793276

Irwin, R J; Lerner, M R; Bealer, J F; Lightfoot, S A; Brackett, D J; Tuggle, D W

1998-10-01

175

STUDY OF ANOMALOUS MINE BLASTS  

Microsoft Academic Search

The Altai-Sayan mining region located east of Novosibirsk, Russia, comprises over 72 mines which are located between 7 and 559 km from the International Monitoring System (IMS) primary 3-component station ZAL. We have origin time and location estimates of 853 blasts that have occurred in this trend between 1\\/1\\/1995 and 6\\/30\\/2000. The mines are known to use millisecond delay-fire blasting

Michael A. H. Hedlin; Vitaly I. Khalturin

176

Water blasting paint removal methods  

NASA Astrophysics Data System (ADS)

Water blasting is a paint removal technique that has been used for cleaning and paint removal for many years. The major disadvantages until recently were the slow rate of paint removal and the possibility of damage to the substrate from the high pressures used. With the improvement in nozzle design that allows for higher operating pressures and the use of environmentally compliant paint softeners or strippers, water blasting is becoming a recognized technique for paint removal in the aircraft industry.

Foster, Terry

1995-04-01

177

Controlled toothbrush abrasion of softened human enamel.  

PubMed

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

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

2008-07-29

178

Tyre-blast injuries.  

PubMed

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

Murty, O P

2009-01-29

179

Geothermal energy market study on the Atlantic Coastal Plain. GRITS: A computer program for the economic evaluation of direct-use applications of geothermal energy  

NASA Astrophysics Data System (ADS)

The Geothermal Resource Interactive Temporal Simulation (GRITS) model calculates the cost and revenue streams for each year in the lifetime of a project that utilizes low to moderate temperature geothermal resources. With these two estimates, the net present value of the project can be determined for each year. 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.

Barron, W.; Kroll, P.; Weissbrod, R.; Toth, W. J.

1980-06-01

180

Calculation of the depth of penetration of an abrasive particle in abrasive-impact wear  

Microsoft Academic Search

of the contact load Pim, the number of load cycles n, the stress state of local volumes of the metal -- which can be expressed through the depth of penetration h of the abrasive particles into the surface layer-- and the complex of mechanical properties of the metal and ab ras ire. We will examine a method of calculating the

G. M. Sorokin; V. P. Eroshkin; S. P. Grigor'ev

1983-01-01

181

Compton scattering sequence reconstruction algorithm for the liquid xenon gamma-ray imaging telescope (LXeGRIT)  

Microsoft Academic Search

The Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT) is a balloon born experiment sensitive to (gamma) -rays in the energy band of 0.2 - 20 MeV. The main detector is a time projection chamber filled with high purity liquid xenon (LXeTPC), in which the three-dimensional location and energy deposit of individual (gamma) -ray interactions are accurately measured in one homogeneous volume.

Uwe G. Oberlack; Elena Aprile; Alessandro Curioni; Valeri Egorov; Karl-Ludwig Giboni

2000-01-01

182

Preliminary results from the 1999 balloon flight of the Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)  

Microsoft Academic Search

LXeGRIT is a balloon-borne Compton telescope employing a large volume liquid xenon time projection chamber (LXe-TPC) as the central (gamma) -ray detector. It is designed to image (gamma) - rays in the energy range of approximately 200 keV to 20 MeV, with an angular resolution of about 3 degrees (1 sigma) at 2 MeV, within a field-of-view (FOV) of about

Elena Aprile; Uwe G. Oberlack; Alessandro Curioni; Valeri Egorov; Karl-Ludwig Giboni; Sandro Ventura; Tadayoshi Doke; Jun Kikuchi; Kyoko Takizawa; Edward L. Chupp; Philip P. Dunphy

2000-01-01

183

Microstructural Effects in Abrasive Wear. Second Annual Progress Report, August 10, 1982-August 12, 1983.  

National Technical Information Service (NTIS)

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 t...

T. H. Kosel

1983-01-01

184

Laboratory abrasive wear tests: investigation of test methods and alloy correlation  

Microsoft Academic Search

When screening materials, laboratory abrasive wear testing is a quick and inexpensive way of obtaining large quantities on information on wear rates and wear mechanisms. Typical laboratory abrasive wear tests approximate two- and three-body abrasion. The Albany Research Center, however, uses a suite of four laboratory abrasion, gouging–abrasion, and impact–gouging abrasion wear tests to rank materials for wear applications in

J. A. Hawk; R. D. Wilson; J. H. Tylczak; Ö. N. Do?an

1999-01-01

185

Mars Exploration Rovers' Rock Abrasion Tool  

NASA Astrophysics Data System (ADS)

Each of the twin 2003 Mars Exploration Rovers will be equipped with a Rock Abrasion Tool (RAT) designed and tested by Honeybee Robotics. The RAT is a robotic grinding tool and science instrument about the size of a soda can and weighing less than 690 grams that is carried by the robotic arm or Instrument Deployment Device (IDD) of the rover. The primary purpose of the RAT is to remove the dust and surface rind from Mars rock targets to reveal the underlying petrographic features. After the RAT is placed and preloaded against the target rock by the IDD, all operations of the RAT are performed autonomously. Using three small motors to drive the rotation, revolve and z-axis subassemblies the RAT removes a 45 mm diameter, 5 mm deep patch of rock. The RAT has a resin-bonded diamond abrasion wheel and two brushes to provide a clean observation surface for the three surface instruments - APXS, Microscopic Imager and Moessbauer Spectrometer. Detailed design and operation descriptions, as well as recent qualification and operational testing results will be presented.

Gorevan, S.; Myrick, T.; Davis, K.; Ji, J.; Bartlett, P.; Mukherjee, S.; Arafat, T.

2003-04-01

186

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...

187

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 ...

188

Particle motion and stain removal during simulated abrasive tooth cleaning  

Microsoft Academic Search

Stain removal from teeth is important both to prevent decay and for appearance. This is usually achieved using a filament-based toothbrush with a toothpaste consisting of abrasive particles in a carrier fluid. This work has been carried out to examine how these abrasive particles interact with the filaments and cause material removal from a stain layer on the surface of

R. Lewis; S. C. Barber; R. S. Dwyer-Joyce

2007-01-01

189

Failure analysis of an abrasive cut-off wheel  

Microsoft Academic Search

The relationship between composition, structure, properties and performance is central to the design, use and failure analysis of engineering components. Thermogravimetric analysis (TGA) and wavelength X-ray fluorescence (WRXF) were applied in evaluating the elemental composition and thermal properties, respectively, of a failed abrasive cut-off wheel. The cutting tool, consisting of a bonded abrasive disc, failed prematurely during the routine sectioning

A. T. Riga; C. G. Scott

2001-01-01

190

A Laboratory Method for Assessment of Dentrifrice Abrasivity  

Microsoft Academic Search

This is the report of the Laboratory Abrasion Committee of the American Dental Association (ADA) Dentifrice Program relative to specific methods to measure the in vitro abrasivity of dentifrices. This method was used in two collaborative studies with six participating laboratories. These studies were designed by the ADA Dentifrice Program Statistical Committee and their interpretations form a basis for recommendations

John J. Hefferren

1976-01-01

191

Dry and wet abrasive resistance of Inconel 600 and stellite  

Microsoft Academic Search

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

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

2005-01-01

192

Impact-abrasion behavior of low alloy white cast irons  

Microsoft Academic Search

The impact-abrasion behavior of a series of low alloy white cast irons with different morphologies of eutectic carbide was investigated using a repetitive impact-abrasive wear tester. By means of a defined morphological parameter, the roundness area fraction SFi, the morphology of the eutectic carbide in each alloy was quantitatively assessed. It was found that the mean weight loss of the

Ma Qian; Wang Chaochang

1997-01-01

193

Investigation of material reliabilities under gaseous abrasive wearing conditions  

Microsoft Academic Search

plants the pneumatic systems undergo severe abrasion, which is characterized by being nonuniform and localized [1]. Local wearing is of primary significance in limiting the service life of pneumatic pipework. A method has been developed in the Moscow Institute of Chemical Engineering for determining the wearing rates of materials operating under gaseous abrasive wearing conditions, by directing a jet of

V. I. Krasnov; I. B. Zhilinskii

1973-01-01

194

Experimental investigations into rotating workpiece abrasive flow finishing  

Microsoft Academic Search

Abrasive flow finishing (AFF) is used to deburr, polish or radius surfaces and edges by flowing a semisolid abrasive medium over the intended surface to be finished. Such finishing operations play a crucial role in manufacturing process of machine parts. The cost escalates sharply when the requirement is to achieve surface roughness values near nano levels. The need for finishing

Mamilla Ravi Sankar; V. K. Jain; J. Ramkumar

2009-01-01

195

Fluid flow analysis of magnetorheological abrasive flow finishing (MRAFF) process  

Microsoft Academic Search

A new precision finishing process called magnetorheological abrasive flow finishing (MRAFF), which is basically a combination of abrasive flow machining (AFM) and magnetorheological finishing (MRF), has been developed for nano-finishing of parts even with complicated geometry for a wide range of industrial applications. This paper deals with the theoretical investigations into the mechanism of MRAFF process to study the effects

Manas Das; V. K. Jain; P. S. Ghoshdastidar

2008-01-01

196

Improving Electrical Discharge Machined Surfaces Using Magnetic Abrasive Finishing  

Microsoft Academic Search

A recast layer is invariably present on surfaces produced by electrical discharge machining (EDM). For some metals with high hardness, the recast layer may contain micro-cracks. This damaged layer can affect the service life of the parts produced by this method. This investigation demonstrates that magnetic abrasive finishing (MAF) process using unbonded magnetic abrasives (UMA), can improve the quality of

Biing-Hwa Yan; Geeng-Wei Chang; Jung-Hsien Chang; Rong-Tzong Hsu

2004-01-01

197

AN EXPERIMENTAL ANALYSIS OF MAGNETIC ABRASIVES FINISHING OF PLANE SURFACES  

Microsoft Academic Search

Magnetic abrasive finishing (MAF) uses magnetic force of very low magnitude applied on ferromagnetic abrasive particles to obtain very high level surface finish. The process has been investigated extensively in the finishing of cylindrical surfaces. This paper reports an experimental work on the analysis of surface roughness and material removal using response surface method in the MAF of plane surfaces.

Berhanu Girma; Suhas S. Joshi; M. V. G. S. Raghuram; R. Balasubramaniam

2006-01-01

198

Diamond particle shape: Its measurement and influence in abrasive wear  

Microsoft Academic Search

The classification of diamond particles in terms of their abrasive characteristics is addressed in this work. Specifically, diamond particles of different grades have been studied in terms of their shape to identify useful trends and correlations with experimental wear rate. Ten diamond types, typically used by the abrasives industry and exhibiting varied shape, were selected. They included highly geometric single

Dennis V. De Pellegrin; Normand D. Corbin; Gary Baldoni; Andrew A. Torrance

2009-01-01

199

Response of isotropic brittle materials to abrasive processes.  

National Technical Information Service (NTIS)

This paper is an overview of brittle material responses to abrasion. It proposes a 3 region model for both 2-body and 3-body wear, two regions being where removal rate is nearly independent of abrasive size at otherwise identical conditions and a transiti...

N. J. Brown B. A. Fuchs P. P. Hed I. F. Stowers

1989-01-01

200

Post-emergence weed control through abrasion with an approved organic fertilizer  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn gluten meal (CGM) is an approved organic fertilizer and preemergence herbicide that can be manufactured in the form of grit. This grit was tested for its ability to abrade seedlings of the summer annual weedy grass, Setaria pumila, when plants were in the 1- to 5-leaf stages of growth. It was p...

201

Solidification Structure and Abrasion Resistance of High Chromium White Irons  

SciTech Connect

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

Dogan, O.N.; Hawk, J.A.; Laird, George, II

1997-06-01

202

Solidification structure and abrasion resistance of high chromium white irons  

SciTech Connect

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

Dogan, O.N.; Hawk, J.A.; Laird, G. II [Dept. of Energy, Albany, OR (United States). Albany Research Center

1997-06-01

203

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

PubMed

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

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

2012-04-07

204

Experimental Rock-on-Rock Abrasive Wear Under Aqueous Conditions: its Role in Subglacial Abrasion  

NASA Astrophysics Data System (ADS)

We have determined experimentally the rate of abrasive wear of rock on rock for a range of rock types as a function of normal stress and shear displacement. Unlike abrasive wear in fault zones, where wear products accumulate as a thickening gouge zone, in our experiments wear particles were removed by flowing water. The experiments are thus directly pertinent to one of the most important processes in subglacial erosion, and to some extent in river incision. Wear was produced between rotating discs machined from rock samples and measured from the progressive approach of the disc axes towards each other under various levels of normal load. Shear displacements of several km were produced. Optical and scanning electron microscopy were used to study the worn rock surfaces, and particle size distributions in wear products were characterized using a laser particle size analyzer. Rock types studied were sandstones of various porosities and cement characteristics, schists and a granite. In all cases abrasion rate decreased logarithmically with displacement by up to 2 orders of magnitude until a steady state was approached, but only after at least 1 km displacement. The more porous, less-well cemented rocks wore fastest. Amount of abrasion could be characterized quantitatively using an exponentially decaying plus a steady-state term. Wear rate increased non-linearly with normal contact stress, apparently to an asymptote defined by the unconfined compressive strength. Microstructural study showed that the well-cemented and/or lowest porosity rocks wore by progressive abrasion of grains without plucking, whereas whole grains were plucked out of weakly-cemented and/or more porous rocks. This difference in behavior was reflected in wear-product particle size distributions. Where whole-grain plucking was possible, wear products were dominated by particles of the original grain size rather than finer rock flour. Comparison of our results to glacier basal abrasive wear estimated from suspended sediment load (Findeln Glacier, Switzerland) showed the steady-state experimental data seriously to underestimate the natural wear rate. This suggests continuous resetting of the subglacial surface occurs, so that wear is continuously in the 'running-in' stage.

Rutter, E. H.; Lee, A. G.

2003-12-01

205

Blasting, graphical interfaces and Unix  

SciTech Connect

A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphical interface has been developed. DMC is currently executed on both Sun SPARCstation 2 and Sun SPARCstation 10 platforms and routinely used to model bench and crater blasting problems. This paper will document the design and development of the full-featured interface to DMC. The development of the interface will be tracked through the various stages, highlighting the adjustments made to allow the necessary parameters to be entered in terms and units that field blasters understand. The paper also discusses a novel way of entering non-integer numbers and the techniques necessary to display blasting parameters in an understandable visual manner. A video presentation will demonstrate the graphics interface and explains its use.

Knudsen, S. [RE/SPEC, Inc., Albuquerque, NM (United States); Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States)

1993-11-01

206

Surface Mining and the Natural Environment: Blasting.  

National Technical Information Service (NTIS)

Blasting is the process commonly used to fracture the rock strata overlying a mineral seam. It is an important component of many surface mining operations. The technical guide will discuss several aspects of blasting, including a description of the method...

M. L. Clar J. M. Ward

1980-01-01

207

Evaluation of Plastic Media Blasting Equipment.  

National Technical Information Service (NTIS)

This report evaluates the design of plastic media blasting (PMB) equipment currently used in the military and private industry. Five PMB functional equipment groups were established: blasting, floor recovery, media recycling, ventilation, and dense partic...

E. Radonich M. Wells

1987-01-01

208

Low Cost Oxygen for Blast Furnace.  

National Technical Information Service (NTIS)

A low cost process is examined which provides oxygen enrichment of blast air for blast furnaces to increase steel production without increasing the steelmaking or final finishing facilities. The proposed process is designed to separate the oxygen from nit...

R. Jablin

1980-01-01

209

Brain Injury Risk from Primary Blast.  

National Technical Information Service (NTIS)

Objectives: Increased use of explosive devices in recent military conflicts have resulted in, blast overpressure is the primary cause of traumatic brain injury among combat veterans (Owens, 2008). Primary blast injury has been studied extensively in air-c...

C. R. Bass K. A. Rafaels M. B. Panzer R. S. Salzar W. A. Woods

2012-01-01

210

30 CFR Blasting - Surface and Underground  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Surface and Underground Blasting Electric Blasting Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...in the same work area shall be initiated from one source. Electric BlastingâSurface and...

2010-07-01

211

Blast Pendulum Testing of Milliken Tegris Panels.  

National Technical Information Service (NTIS)

Milliken contracted Southwest Research Institute (SwRI) to conduct blast pendulum tests on various panels. The blast pendulum allows one to investigate a material's capability of mitigating sample deformation and bulk structural loading that result from '...

D. J. Grosch E. J. Sagebiel H. Eleazer

2008-01-01

212

Explosive blasting method and means  

SciTech Connect

An explosive blasting method and apparatus are claimed for producing rock fragmentation and reducing the amplitude of seismic effects (ground vibration) in the vicinity of the blast. It utilizes an air gap method and apparatus for superheating the air surrounding the charge in a borehole. This raises the pressure therein coupled with the use of multiple detonation points along the borehole for the reduction of burn time. This reduces the quantity of explosives used along with a marked reduction of seismic shock, sound, and dust effects to the surrounding area.

Bowling, D.S.; Moore, R.N.

1983-05-10

213

Nucleon Form Factors from BLAST  

NASA Astrophysics Data System (ADS)

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.

Kohl, Michael

2009-08-01

214

Gun muzzle blast and flash  

NASA Astrophysics Data System (ADS)

A repository of fundamental experimental and analytical data concerning the complex phenomena associated with gun-muzzle blast and flash effects is presented, proceeding from gun muzzle signatures to modern gun-propulsion concepts, interior and transitional ballistics, and characterizations of blast-wave research and muzzle flash. Data are presented in support of a novel hypothesis which explains the ignition of secondary flash and elucidates the means for its suppression. Both chemical and mechanical (often competing) methods of flash suppression are treated. The historical work of Kesslau and Ladenburg is noted, together with French, British, Japanese and American research efforts and current techniques of experimental characterization for gun muzzle phenomena.

Klingenberg, Guenter; Heimerl, Joseph M.

215

Clinical Outcome of 802 Immediately Loaded 2-stage Submerged Implants with a New Grit-Blasted and Acid-Etched Surface: 12-month Follow-up  

Microsoft Academic Search

Purpose: The aim of this study was to evaluate the clinical outcome of delayed or immediately loaded implants of 3 different implant macrodesigns. The hypothesis was that no significant differences in implant success would be observed between immediately and delayed loaded implants. Materials and Methods: Between July 2003 and December 2003, 321 patients were consecutively enrolled for this study. Immediate

Marco Degidi; Adriano Piattelli; Peter Gehrke; Francesco Carinci

216

Blast wave investigated using a high enthalpy blast simulator  

Microsoft Academic Search

An experimental study to examine the behavior of blast propagation is described. Its decay characteristics are analyzed to establish an empirical relationship for peak pressure distribution. A scaled length parameter is used in the development of a peak pressure prediction scheme. An assessment is also made to improve the data correlation using the axial Mach disc distance in scaling the

K. C. Phan; C. V. Hurdle

1990-01-01

217

Blast wave investigation using a high enthalpy blast simulator  

Microsoft Academic Search

An experimental study to examine the behavior of blast propagation is described. Its decay characteristics are analyzed to establish an empirical relationship for peak pressure distribution which employs scaled length parameter. An assessment is also made to improve the data correlation using the axial Mach disk distance in scaling the radial distance from the tube exit.

K. C. Phan; C. V. Hurdle

1990-01-01

218

System for supplying blasting media to a media blasting system  

SciTech Connect

This patent describes a pressure pot system for supplying blasting media under pressure to a pressurized blasting conduit for feeding blasting media to one or more blasting guns, the system including a media storage means and a first and second pressure chambers with means for pressurizing and exhausting the first and second chambers, the media storage means being stacked above the pressure chambers with the first pressure chamber stacked above the second pressure chamber; first and second media valve means for providing communication between the storage means and the first pressure chamber and between the pressure chambers, respectively; air valve means for controlling the air pressurizing and exhausting of the first and second pressure chambers, the improvement comprising: means for opening and closing the first and second media valve means and the air valve means, the first, second and air valve means being offset from each other in both vertical and horizontal dimensions; push rods extending vertically upward from the valve means and spaced one from the other for actuating the valve means to open and close the same; an overhead cam shaft means mounted above the push rods and having a plurality of spaced cams, each of the cams being aligned and operatively associated with one of the push rods for actuating the push rods and thereby the valve means to control the opening and closing of the first and second media valve means and the air valve means; and actuating means for actuating the cam shaft means.

Van Kuiken, L.L. Jr.

1988-10-25

219

Design of an impact abrasion testing machine  

NASA Astrophysics Data System (ADS)

By using a cam-flat follower-impact shaft with a crank-flat rotating anvil system, the machine to be described can create various impact abrasion conditions to simulate a large range of industrial situations encountered in this field. The main features of the machine are the long working life of the flat rotating anvil, which works in the same way as that of the disk in a pin-on-disk wear tester, and the accurate control of both the impact energy delivered to the specimen and the total sliding distance of the specimen on the anvil. Statistical analysis of test results on the machine with EN24 steel and cast high manganese steel shows that the uncertainty of the population mean is within +/- 4.7% of the sample mean under a 95% confidence level of student distribution, which indicates a very good accuracy of test.

Zhang, D.; Beeley, P. R.; Baker, A. J.

1994-04-01

220

Lightweighting large optics with abrasive waterjets  

NASA Astrophysics Data System (ADS)

A new approach to lightweighting large optics using the abrasive waterjet (AWJ) milling process has been developed and has demonstrated that significant weight reductions in glass face sheets can be achieved. The AWJ glass milling process has been developed to offer a safe and low cost machining alternative over conventional methods that are considered a high risk machining process. The lightweighting approach has been oriented towards precise controlled depth milling of isogrid pattern pockets in the back side of optic face sheets. The AWJ milling process has been successfully applied to lightweighting a wide range of materials; such as ULE, Zerodur, Fused Silica, Fused Quartz, and Pyrex, with part sizes ranging from 70 mm (3 inches) in diameter to in excess of 2 meters (80 inches) in diameter.

Miles, Peter J.

1998-12-01

221

An equivalent method for blasting vibration simulation  

Microsoft Academic Search

Due to the complicated blasting load, the diversified medium models and various constitutive relations of the rock mass, and a huge job for simulating blasting of multiple holes, it is very difficult and costly to simulate the blasting vibration accurately in numerical computation. This paper presents an equivalent simulation method so as to transform this complex dynamic problem into an

Wenbo Lu; Jianhua Yang; Ming Chen; Chuangbing Zhou

2011-01-01

222

The pathology of primary blast overpressure injury  

Microsoft Academic Search

Primary blast injury occurs in civilian and military detonations and from the firing of weapon systems. The pathology of primary blast injury has been reported for the last 70 years and has primarily been limited to descriptions of gross pathology and histology. Commonly accepted tenets have not been confirmed as blast overpressure experiments in enclosures and with multiple detonations have

Maria A. Mayorga

1997-01-01

223

Physical Mechanisms of Quarry Blast Sources.  

National Technical Information Service (NTIS)

Models of quarry blasts may serve to develop efficient and robust methods for discriminating quarry blasts from other sources. In this report, we present progress on modeling quarry blasts at the Chemline quarry in central Texas and the Black Thunder mine...

T. G. Barker K. L. mcLaughlin J. Bonner

1997-01-01

224

29 CFR 1926.912 - Underwater blasting.  

Code of Federal Regulations, 2013 CFR

...moored or anchored within 1,500 feet shall be notified before a blast is fired. (e) No blast shall be fired while any swimming or diving operations are in progress in the vicinity of the blasting area. If such operations are in progress, signals...

2013-07-01

225

Blast waves in frozen soils  

Microsoft Academic Search

We present results of experimental studies of spherical blast waves in seasonally frozen soils with different physical and mechanical properties at different temperatures. A comparison with results in [i, 2] shows that the wave parameters depend strongly on the characteristics of the soil in the initial unfrozen state and on the temperature. When the temperature falls, the maximum stresses and

G. M. Lyakhov; G. B. Frash

1983-01-01

226

Gun Blast from Naval Guns.  

National Technical Information Service (NTIS)

The available data on gun blasts from naval guns are complied utilizing computer curve fitting techniques. Curves of peak free-air pressure are presented for all naval guns, ranging in size from 20 mm to 16in./50. In addition, curves of arrival time, dura...

M. F. Walther

1972-01-01

227

Mixing Effect in Internal Blast  

NASA Astrophysics Data System (ADS)

Detonation product gases are usually assumed to be completely mixed with an existing atmosphere by the time a peak quasi-static pressure (Pqs) is reached within an enclosed internal blast environment. With incomplete mixing, however, comes a loss in pressure from unburned fuel as well as a previously unrecognized source of error: heat capacity of the gas increases substantially with temperature, providing an energy sink in regions of unmixed hot gas. Our objective was to look at the extent of mixing by measuring gas temperature at several locations within a blast chamber at the time of peak Pqs. We recorded ranges of up to 400° C depending on charge location within the chamber, which is presumed to affect turbulence and mixing. Losses in peak Pqs of up to 13% may be attributed to this mixing effect for 1-kg Pentolite charges in a 62-m3 chamber in the simple geometries tested. A reasonably accurate Pqs may be extracted from blast wave reverberations in a chamber, allowing a closer look at effects such as gas mixing and consistency among multiple gages. These results point to an explanation for missing energy and a better understanding of heat flow in internal blast.

Granholm, R. H.; Sandusky, H. W.

2009-12-01

228

Effect of microstructure on slurry abrasion response of En31 steel  

Microsoft Academic Search

Wear by slurry abrasion occurs in extruders, slurry pumps, and pipes carrying slurry of minerals and ores in mineral processing industries. The wear life of components used under slurry abrasion conditions is governed by the process parameters, properties of abrasive particles in slurry and material properties. In the present work slurry abrasion response of heat treated En-31 steel was studied.

S. G. Sapate; A. D. Chopde; P. M. Nimbalkar; D. K. Chandrakar

2008-01-01

229

Comparison of abrasion model differences in heavy ion fragmentation: Optical versus geometric models  

Microsoft Academic Search

Using an abrasion-ablation collision model, which includes contributions from frictional-spectator interactions and electromagnetic dissociation, analyses of the sensitivities of predicted fragmentation cross sections to the choice of a particular abrasion formalism are made using both geometric and optical potential abrasion models. Most cross section differences obtained using the two abrasion models are less than the present experimental uncertainties, suggesting that

L. W. Townsend; J. W. Wilson; F. A. Cucinotta; J. W. Norbury

1986-01-01

230

Chemical mechanical polishing with fixed abrasives using different subpads to optimize wafer uniformity  

Microsoft Academic Search

Chemical mechanical polishing (CMP) processes are widely used in the semiconductor industry and are conventionally carried out using abrasive slurry and a polishing pad. In an alternative procedure, called ‘slurry free CMP’, the abrasive particles are embedded in the pad material (‘fixed abrasives’). A microreplicated resin layer of pyramids filled with the abrasives is placed on top of a rigid

P van der Velden

2000-01-01

231

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

Microsoft Academic Search

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

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

2007-01-01

232

Study of an internal magnetic abrasive finishing using a pole rotation system  

Microsoft Academic Search

An internal magnetic abrasive finishing process using a pole rotation system was proposed to produce highly finished inner surfaces of workpieces used in critical applications. Previous research found that the process incorporating one of the characteristic behaviors of the abrasive, the jumbling of the abrasive, results in aggressive contact of the abrasive against the inner surface, disturbing the smooth surface

Hitomi Yamaguchi; Takeo Shinmura

2000-01-01

233

Prediction System of Magnetic Abrasive Finishing (MAF) on the Internal Surface of a Cylindrical Tube  

Microsoft Academic Search

This study mainly used magnetic abrasive finishing (MAF) to explore a stainless steel SUS304 cylindrical tube related to the processing characteristic and the prediction system. The self-made adjustable electricity polishing mechanism was assembled on a magnetic abrasive machine. The cylindrical stainless steel tube was filled with magnetic abrasive, which consisted of sintered iron and aluminum oxide powder. Magnetic abrasive in

Ching-Lien Hung; Wei-Liang Ku; Lieh-Dai Yang

2010-01-01

234

An Upgraded Data Acquisition System for the Balloon-Borne Liquid Xenon Gamma-Ray Telescope LXeGRIT  

Microsoft Academic Search

LXeGRIT is a balloon-borne Compton telescope for MeV gamma-ray astrophysics,\\u000abased on a liquid xenon time projection chamber (LXe-TPC) with charge and light\\u000areadout. The first balloon flights in 1997 revealed limitations of the trigger\\u000aelectronics and the data acquisition (DAQ) system, leading to their upgrade.\\u000aNew electronics was developed to handle the xenon scintillation light trigger.\\u000aThe original processor

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

2000-01-01

235

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

Microsoft Academic Search

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,

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

2000-01-01

236

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

SciTech Connect

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.

Kosel, T.H.

1983-08-12

237

Undersoekningar av Slipvaerdesmetoden (Investigation of the Swedish Abrasion Value).  

National Technical Information Service (NTIS)

Different factors that influence the Swedish Abrasion Value, in the original and modified form have been investigated in 1984. A new equipment has been bought for performing the modified test parallel to the original test during a transition period. Inves...

P. Hoebeda J. Chytla

1985-01-01

238

Improved wound healing in blue LED treated superficial abrasions  

NASA Astrophysics Data System (ADS)

A blue-LED photocoagulator device was designed in order to induce a selective photocoagulation effect in superficial bleeding. An in vivo study in rat back skin evidenced an improved healing process in the LED treated abrasions.

Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Bacci, Stefano; De Siena, Gaetano; Cicchi, Riccardo; Pavone, Francesco; Alfieri, Domenico

2013-06-01

239

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

Code of Federal Regulations, 2013 CFR

...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 procurement product...

2013-01-01

240

Skin Abrasion Effects of Lunar Dust Relevant to Astronauts  

NASA Astrophysics Data System (ADS)

Future astronauts exploring the Moon will need to consider the biological effects of lunar dust, including potential inhalation toxicity, ocular effects and skin effects. This paper will focus on skin abrasivity.

Jones, L.; Jacques, S.; Tranfield, E.; Rask, J.; Kerschmann, R.; Loftus, D.

2008-03-01

241

Effects of fluvial abrasion on shapes of quartz sand grains  

SciTech Connect

The effects of abrasion on the shapes of medium and fine quartz sand grains that are transported through a 300-mi (500-km) stretch of the Mississippi River were determined by Fourier grain-shape measurement and scanning electron microscopy. The results indicate that the abrasion of medium and fine quartz sand grains in the low-gradient stream does not significantly affect their source-inherited shapes.

Peterson, M.; Mazzullo, J.

1987-09-01

242

Modeling of Polishing Mechanism in Magnetic Abrasive Polishing  

Microsoft Academic Search

Magnetic Abrasive Polishing (MAP) is a super-finishing process primarily used for polishing of non- magnetic and hard materials like, ceramics and stainless steel. This paper deals with the detailed parametric study in polishing of stainless steel work surface. Statistically designed experiments based on Taguchi methods show that size-ratio, tool-work surface clearance, polishing speed, magnetic abrasive diameter and polishing time have

M. G. V. S. Raghuram; Suhas S. Joshi

243

Optimizing fracture toughness and abrasion resistance in white cast irons  

NASA Astrophysics Data System (ADS)

A series of twelve Cr-Mo white irons varying in carbide volume from 7 to 45 pct were tested for dynamic fracture toughness and wet sand abrasion resistance. Carbon content was varied from 1.4 to 3.9 pct. Two matrix microstructures were employed, and the compositions (copper and chromium content) were varied to assure constant matrix compositions. Chromium was varied from 11.6 to 25.7 pct. In addition, one composition of white iron was subjected to thirty different heat treatments to define the effect of matrix microstructure on dynamic fracture toughness and abrasion resistance. It was shown that for the abrasive wear system used, a carbide volume of about 30 pct represented an optimum quantity, above which abrasion resistance decreased. Martensitic irons provided consistently better abrasion resistance than austenitic irons. Dynamic fracture toughness decreased with carbide volume, as expected. Higher toughness values were obtained with predominantly austenitic matrix microstructures than with predominantly martensitic matrix microstructures. Considering both abrasion resistance and fracture toughness, it was shown that heat treated irons could provide an optimal combination of these properties.

Gahr, Karl-Heinz Zum; Doane, Douglas V.

1980-04-01

244

Abrasive-waterjet machining of isogrid structures  

NASA Astrophysics Data System (ADS)

An experimental investigation was conducted to determine the feasibility of machining isogrid structures with abrasive-waterjets (AWJs). The main objective was to mill isogrid patterns in surfaces with accurate depth control using an AWJ. Three different approaches using AWJs were tested: linear cutting of isogrid patterns for diffusion bonding, milling with conventional AWJ nozzles, and milling with a single-angled rotary AWJ nozzle. It was shown that pocket milling with conventional AWJs is the most feasible of those tested. The milling can be done internally on preformed aluminum tubes, and the AWJ can also be used on materials other than aluminum. Accurate depth control can be achieved at high productivity rates. As an example, it is projected that a 48-inch-diameter skirt 12 inches high could be milled with an isogrid pattern in 6.3 hours. Milled isogrid patterns can be controlled to 0.001 inch, and thin walls of less than 0.025 inch are achievable. Milling isogrid patterns with conventional AWJs could be very economical, but additional development efforts are required to optimize the milling process and to demonstrate the milling of prototype parts.

Hashish, Mohamed; Marvin, Mark; Monserud, David

1990-12-01

245

Computed tomography to quantify tooth abrasion  

NASA Astrophysics Data System (ADS)

Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

2010-08-01

246

Surface quality control in diamond abrasive finishing  

NASA Astrophysics Data System (ADS)

The paper presents a procedure for measuring laser radiation reflection and scattering coefficients of polished surface. A relation between the scattered light intensity and the polished surface roughness is studied. It is demonstrated that colorimetric characteristics of non-metallic materials can be determined from the light scattering and reflection coefficients. This work has demonstrated a possibility of and created prerequisites for the development of an express method for tentative assessment of polished surface roughness. Of interest is the use of the ?(Rz) function for the purposes of quality inspection of polished surfaces of natural and synthetic stone and other non-metallic materials. It was established that the most relevant parameter of roughness, which can be defined by the light reflection is Rz. The Dependency of the reflection factor from parameter of roughness Rz was approximated by formula with inaccuracy 5-10%. Inaccuracy of the determination of roughness Rz has formed 1%. It was shown that method of the surface roughness control using the light reflection factor is the most efficient for surfaces with roughness Rz <0.3 microns, typical for finish diamond-abrasive machining.

Filatov, Yuriy D.; Sidorko, Volodymyr I.; Filatov, Olexandr Yu.; Yaschuk, Vasil P.; Heisel, Uwe; Storchak, Michael

2009-06-01

247

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

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.

William S. McPhee

2001-08-31

248

Abrasion of mild steel in wet and dry conditions with the rubber and steel wheel abrasion apparatus  

Microsoft Academic Search

Abrasion behaviour with a rotating wheel-type apparatus has been examined with angular alumina and rounded silica abrasives as a function of test conditions, namely wheel-type (rubber wheel or steel wheel) and environment (dry or wet conditions). Water tends to lubricate the contact between the particles and the testpiece, especially with small and\\/or rounded particles and thus the wear rate is

S. Wirojanupatump; P. H. Shipway

2000-01-01

249

Self-modulating abrasive medium and its application to abrasive flow machining for finishing micro channel surfaces  

Microsoft Academic Search

This study developed a self-modulating abrasive medium whose viscosity and fluidity can be adjusted during the processing\\u000a period. The complex micro channel was fabricated on the stainless steel (SUS304) by using wire electrical discharge machining\\u000a (wire-EDM). An experiment of employing abrasive flow machining (AFM) was conducted to evaluate the characteristics of various\\u000a levels of roughness and finishing of the micro

Hsinn-Jyh Tzeng; Biing-Hwa Yan; Rong-Tzong Hsu; Yan-Cherng Lin

2007-01-01

250

Comparison of the efficacy of prophylaxis pastes with conventional abrasives or a new self-adjusting abrasive.  

PubMed

A newly developed prophylaxis paste that contains perlite as an abrasive medium (Cleanic) was compared to conventional prophylaxis pastes with regard to relative dentin and enamel abrasion, cleaning ability, and polishing power. Rubber cups and nylon brushes were used as paste carriers. Water, flour of pumice, and the dentin-polishing paste CCS 40 served as controls. The tested prophylaxis pastes, selected according to their popularity among clinicians, were CCS 250, Détartrine Z, Nupro Coarse, and Zircate. The Prophylaxis Paste Index was created to assess the clinical potential of the various prophylaxis pastes more accurately. The Index was computed for dentin as cleaning ability dended by relative dentin abrasion x surface roughness (in Ra) x 10, and for enamel as cleaning ability dended by relative enamel abrasion x surface abrasion (in Ra). On dentin and enamel, Cleanic consistently yielded low relative dentin and enamel abrasion values, a good cleaning ability, and low surface roughness scores with both rubber cups and nylon brushes. Of all tested prophylaxis pastes, Cleanic excelled in the Prophylaxis Paste Index on dentin and enamel and with both rubber cup and nylon brush applications. Therefore, a perlite-containing prophylaxis paste has broad professional therapeutic indications and may be used universally as a single paste to clean and polish both dentin and enamel. PMID:8390067

Lutz, F; Sener, B; Imfeld, T; Barbakow, F; Schüpbach, P

1993-03-01

251

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

SciTech Connect

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.

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

252

Primary and secondary skeletal blast trauma.  

PubMed

This study examines primary (resulting from blast wave) and secondary (resulting from disintegrated, penetrating fragments) blast trauma to the skeleton. Eleven pigs were exposed to semi-controlled blast events of varying explosive type, charge size, and distance, including some cases with shrapnel. Skeletal trauma was found to be extensive, presenting as complex, comminuted fractures with numerous small, displaced bone splinters and fragments. Traumatic amputation of the limbs and cranium was also observed. Fractures were concentrated in areas nearer the blast, but there was generally no identifiable point of impact. Fractures were more random in appearance and widespread than those typically associated with gunshot or blunt force injury events. These patterns appear to be uniquely associated with blast trauma and may therefore assist forensic anthropologists and other forensic examiners in the interpretation of skeletal trauma by enabling them to differentiate between blast trauma and trauma resulting from some other cause. PMID:21981586

Christensen, Angi M; Smith, Victoria A; Ramos, Vanessa; Shegogue, Candie; Whitworth, Mark

2011-10-07

253

Abrasive rolling effects on material removal and surface finish in chemical mechanical polishing analyzed by molecular dynamics simulation  

Microsoft Academic Search

In an abrasive chemical mechanical polishing (CMP) process, materials were considered to be removed by abrasive sliding and rolling. Abrasive sliding has been investigated by many molecular dynamics (MD) studies; while abrasive rolling was usually considered to be negligible and therefore was rarely investigated. In this paper, an MD simulation was used to study the effects of abrasive rolling on

Lina Si; Dan Guo; Jianbin Luo; Xinchun Lu; Guoxin Xie

2011-01-01

254

Sorting out abrasion in a gypsum dune field  

NASA Astrophysics Data System (ADS)

Grain size distributions in eolian settings are the result of both sorting and abrasion of grains by saltation. The two are tightly coupled because mobility of particles determines abrasion rate, while abrasion affects the mobility of particles by changing their mass and shape; few field studies have examined this quantitatively. We measured grain size and shape over a 9 km transect downwind of a line sediment source at White Sands National Monument, a gypsum dune field. The sediment source is composed of rodlike (elongate), coarse particles whose shapes appear to reflect the crystalline structure of gypsum. Dispersion in grain size decreases rapidly from the source. Coarse particles gradually become less elongate, while an enrichment of smaller, more elongate grains is observed along the transect. Transport calculations confirm that White Sands is a threshold sand sea in which (1) the predominant particle diameter reflects grains transported in saltation under the dune-forming wind velocity and (2) smaller, elongate grains move in suspension under this dominant wind. Size-selective transport explains first-order trends in grain size; however, abrasion changes the shape of saltating grains and produces elongate, smaller grains that are spallation and breaking products of larger particles. Both shape and size changes saturate 5-6 km downwind of the source. As large particles become more equant, abrasion rates slow down because protruding regions have been removed. Such asymptotic behavior of shape and abrasion rate has been observed in theory and experiment and is likely a generic result of the abrasion process in any environment.

Jerolmack, Douglas J.; Reitz, Meredith D.; Martin, Raleigh L.

2011-06-01

255

Modeling Coal Seam Damage in Cast Blasting  

SciTech Connect

A discrete element computer program named DMC_BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting (Preece & Taylor, 1989). This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in two dimensions. DMC_BLAST calculations compare favorably with data from actual bench blasts (Preece et al, 1993). Coal seam chilling refers to the shattering of a significant portion of the coal leaving unusable fines. It is also refereed to as coal damage. Chilling is caused during a blast by a combination of explosive shock energy and movement of the adjacent rock. Chilling can be minimized by leaving a buffer zone between the bottom of the blastholes and the coal seam or by changing the blast design to decrease the powder factor or by a combination of both. Blast design in coal mine cast blasting is usually a compromise between coal damage and rock fragmentation and movement (heave). In this paper the damage to coal seams from rock movement is examined using the discrete element computer code DMC_BLAST. A rock material strength option has been incorporated into DMC_BLAST by placing bonds/links between the spherical particles used to model the rock. These bonds tie the particles together but can be broken when the tensile, compressive or shear stress in the bond exceeds the defined strength. This capability has been applied to predict coal seam damage, particularly at the toe of a cast blast where drag forces exerted by movement of the overlying rock can adversely effect the top of the coal at the bench face. A simulation of coal mine cast blasting has been performed with special attention being paid to the strength of the coal and its behavior at t he bench face during movement of the overlying material.

Chung, S.H.; Preece, D.S.

1998-11-23

256

Head injury and blast exposure: vestibular consequences.  

PubMed

Young adults are more likely to suffer blast injury and traumatic brain injury (TBI) than other age groups. This article reviews the literature on the vestibular consequences of blast exposure and TBI and concussion. In addition, the vestibular test findings obtained from 31 veterans with a history of blast exposure and/or mild TBI are presented. The authors discuss loss of horizontal semicircular canal function and postural instability related to head injury. Preliminary data suggest the novel theory that otolith organs are uniquely vulnerable to head injury and blast exposure. PMID:21474007

Akin, Faith W; Murnane, Owen D

2011-04-01

257

Health Hazard Assessment for Blast Overpressure Exposures Subtitle - Blast Overpressure Research Program.  

National Technical Information Service (NTIS)

The advent of nuclear blast caused a renewed interest in blast research in the United States. Thus, was the beginning of the Blast Overpressure Program at Kirtland Air Force Base, New Mexico. From the early 1950's through 1997, research on the biomedical,...

B. S. Martinez J. H. Stuhmiller

1999-01-01

258

Factors in Selecting and Applying Commercial Explosives and Blasting Agents.  

National Technical Information Service (NTIS)

In the report commercial blasting compounds are classified according to their nitroglycerin (or equivalent explosive oil) and ammonium nitrate content as dynamites, gelatins, blasting agents, military explosives, and blasting accessories. The ingredients ...

R. A. Dick

1968-01-01

259

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

PubMed Central

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.

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

2007-01-01

260

Explosive signatures: Pre & post blast  

NASA Astrophysics Data System (ADS)

Manuscripts 1 and 2 of this dissertation both involve the pre-blast detection of trace explosive material. The first manuscript explores the analysis of human hair as an indicator of exposure to explosives. Field analysis of hair for trace explosives is quick and non-invasive, and could prove to be a powerful linkage to physical evidence in the form of bulk explosive material. Individuals tested were involved in studies which required handling or close proximity to bulk high explosives such as TNT, PETN, and RDX. The second manuscript reports the results of research in the design and application of canine training aids for non-traditional, peroxide-based explosives. Organic peroxides such as triacetonetriperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD) can be synthesized relatively easily with store-bought ingredients and have become popular improvised explosives with many terrorist groups. Due to the hazards of handling such sensitive compounds, this research established methods for preparing training aids which contained safe quantities of TATP and HMTD for use in imprinting canines with their characteristic odor. Manuscripts 3 and 4 of this dissertation focus on research conducted to characterize pipe bombs during and after an explosion (post-blast). Pipe bombs represent a large percentage of domestic devices encountered by law enforcement. The current project has involved the preparation and controlled explosion of over 90 pipe bombs of different configurations in order to obtain data on fragmentation patterns, fragment velocity, blast overpressure, and fragmentation distance. Physical data recorded from the collected fragments, such as mass, size, and thickness, was correlated with the relative power of the initial device. Manuscript 4 explores the microstructural analysis of select pipe bomb fragments. Shock-loading of the pipe steel led to plastic deformation and work hardening in the steel grain structure as evidenced by optical microscopy and microhardness testing respectively.

Bernier, Evan Thomas

261

Rodent model of direct cranial blast injury.  

PubMed

Traumatic brain injury resulting from an explosive blast is one of the most serious wounds suffered by warfighters, yet the effects of explosive blast overpressure directly impacting the head are poorly understood. We developed a rodent model of direct cranial blast injury (dcBI), in which a blast overpressure could be delivered exclusively to the head, precluding indirect brain injury via thoracic transmission of the blast wave. We constructed and validated a Cranium Only Blast Injury Apparatus (COBIA) to deliver blast overpressures generated by detonating .22 caliber cartridges of smokeless powder. Blast waveforms generated by COBIA replicated those recorded within armored vehicles penetrated by munitions. Lethal dcBI (LD(50) ? 515?kPa) was associated with: (1) apparent brainstem failure, characterized by immediate opisthotonus and apnea leading to cardiac arrest that could not be overcome by cardiopulmonary resuscitation; (2) widespread subarachnoid hemorrhages without cortical contusions or intracerebral or intraventricular hemorrhages; and (3) no pulmonary abnormalities. Sub-lethal dcBI was associated with: (1) apnea lasting up to 15?sec, with transient abnormalities in oxygen saturation; (2) very few delayed deaths; (3) subarachnoid hemorrhages, especially in the path of the blast wave; (4) abnormal immunolabeling for IgG, cleaved caspase-3, and ?-amyloid precursor protein (?-APP), and staining for Fluoro-Jade C, all in deep brain regions away from the subarachnoid hemorrhages, but in the path of the blast wave; and (5) abnormalities on the accelerating Rotarod that persisted for the 1 week period of observation. We conclude that exposure of the head alone to severe explosive blast predisposes to significant neurological dysfunction. PMID:21639724

Kuehn, Reed; Simard, Philippe F; Driscoll, Ian; Keledjian, Kaspar; Ivanova, Svetlana; Tosun, Cigdem; Williams, Alicia; Bochicchio, Grant; Gerzanich, Volodymyr; Simard, J Marc

2011-08-08

262

BLAST autonomous daytime star cameras  

NASA Astrophysics Data System (ADS)

We have developed two redundant daytime star cameras to provide the fine pointing solution for the balloon-borne submillimeter telescope, BLAST. The cameras are capable of providing a reconstructed pointing solution with an absolute accuracy < 5". They are sensitive to stars down to magnitudes ~ 9 in daytime float conditions. Each camera combines a 1 megapixel CCD with a 200mm f/2 lens to image a 2° × 2.5° field of the sky. The instruments are autonomous. An internal computer controls the temperature, adjusts the focus, and determines a real-time pointing solution at 1 Hz. The mechanical details and flight performance of these instruments are presented.

Rex, Marie; Chapin, Edward; Devlin, Mark J.; Gundersen, Joshua; Klein, Jeff; Pascale, Enzo; Wiebe, Donald

2006-07-01

263

Refractories for lining blast furnaces  

SciTech Connect

The authors develop and introduce a technology for the production of chamotte kaolin refractories with a porosity of not more than 12% and a mass proportion of not less than 42% A1/sub 2/O/sub 3/ on the basis of chamotte from high-grade Polozhe kaolin, and also additions to the batch of finely milled mullite-corundum chamotte. Using the new technology, a batch of goods designated ShPD-42 was produced for lining the shafts, bosh, and upper parts of blast furnaces of large capacity.

Fedoruk, R.M.; Baksheeva, V.S.; Karyakina, E.L.; Khmelenko, T.P.; Pitak, N.V.

1986-01-01

264

27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...  

Code of Federal Regulations, 2010 CFR

...Table of separation distances of ammonium nitrate and blasting agents from explosives or...Table of separation distances of ammonium nitrate and blasting agents from explosives or...donor when barricaded (ft.) Ammonium nitrate Blasting agent Minimum thickness...

2010-04-01

265

27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...  

Code of Federal Regulations, 2010 CFR

...Table of separation distances of ammonium nitrate and blasting agents from explosives or...Table of separation distances of ammonium nitrate and blasting agents from explosives or...donor when barricaded (ft.) Ammonium nitrate Blasting agent Minimum thickness...

2009-04-01

266

Prepolishing on a CNC platform with bound abrasive contour tools  

NASA Astrophysics Data System (ADS)

Deterministic microgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-5?m peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an Optipro CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Schoeffler, Adrienne E.; Gregg, Leslie L.; Schoen, John M.; Fess, Edward M.; Hakiel, Michael; Jacobs, Stephen D.

2003-05-01

267

Liquid-abrasive decontamination is versatile, safe, and effective  

SciTech Connect

The safety hazards inherent in electropolishing are eliminated by using liquid abrasives. Electropolishing requires high currents and electrolytes consisting of low-pH acids. In addition, the process generates hydrogen and oxygen. Under these conditions, electropolishing has an inherently high hazard potential, and elaborate precautions are necessary to protect the operating technician. The liquid-abrasive system isolates the operating technician from both direct contact with decontamination solutions and the atmosphere around those solutions. The entire process takes place in an enclosed area, and no corrosive, flammable, or explosive chemicals are involved. Most decontamination operations do not result in true cost savings because of slow processing times, marginal ability to decontaminate to free-release limits, and generation of large volumes of secondary waste. Experience shows that liquid-abrasive decontamination reduces these inadequacies to a minimum. The result is a truly costeffective, volume-reducing operation.

Mis, F.J.; Voit, R.E.

1983-10-01

268

Estimating Abrasivity of Rock by Laboratory and In Situ Tests  

NASA Astrophysics Data System (ADS)

The degree to which a rock abrades another rock is called its "abrasivity". Laboratory tests of abrasivity can be broadly divided into four kinds: drilling, rubbing, turning-operation and tumbling tests. The present study was initiated 30 years ago with the objective of investigating and developing methods for measuring rock abrasivity, and making some contribution towards understanding the relationships between the above test methods. Within the range of tests conducted, the turning-operation test turned out to be superior to the drilling test, albeit slightly, in terms of practicality. We have also conducted in situ tests using rock drills for the last 20 years. The results of those tests have been investigated and compared with the results of laboratory tests. There is a large degree of scatter in the data on gauge loss in button bits, which has obscured any correlations with laboratory data. Some correlations were found between height loss in button bits and laboratory findings.

Okubo, S.; Fukui, K.; Nishimatsu, Y.

2011-03-01

269

Abrasion resistance of in situ Fe-TiC composites  

SciTech Connect

Metal matrix composites containing a high volume fraction of carbide, nitride, boride, and/or oxide particles are frequently the materials of choice for applications which require high wear resistance. It is the very hard second phase particles which imbue the metal matrix composite with its superior wear resistance. For example, additions of titanium carbide (TiC), one of the hardest of the carbides with a Vickers hardness of 19.6--31.4 GPa, can be used to improve the abrasion resistance of iron alloys. In the present study in situ metal matrix composites, containing between 23 and 31 volume percent carbides, were produced from Fe-Ti-C and Fe-Cr-Ti-C melts, and their abrasion resistance was compared with that of unreinforced Fe and a white cast iron using a high-stress pin abrasion test.

Dogan, O.N.; Hawk, J.A. [Bureau of Mines, Albany, OR (United States). Albany Research Center

1995-09-15

270

A Robust Helical Abrasive Flow Machining (HLX-AFM) Process  

NASA Astrophysics Data System (ADS)

Abrasive flow machining (AFM) is a fine finishing process in which an abrasives laden semi-solid paste is used for finishing of internal inaccessible recesses or surfaces. Recently, several modifications in the tooling with/without additional machining action have been tried for increasing the material removal in the AFM. The present study is about a novel development in the AFM process, towards the enhancement of material removal rate while polishing the internal cylindrical surfaces. The modified process is termed as helical abrasive flow machining process (HLX-AFM). Taguchi's quality engineering approach has been applied to the developed HLX-AFM process, leading to the optimization of various process parameters and thus the development of a robust machining process with significantly enhanced material removal.

Brar, B. S.; Walia, R. S.; Singh, V. P.; Sharma, M.

2013-01-01

271

Blast-related traumatic brain injury.  

PubMed

A bomb blast may cause the full severity range of traumatic brain injury (TBI), from mild concussion to severe, penetrating injury. The pathophysiology of blast-related TBI is distinctive, with injury magnitude dependent on several factors, including blast energy and distance from the blast epicentre. The prevalence of blast-related mild TBI in modern war zones has varied widely, but detection is optimised by battlefield assessment of concussion and follow-up screening of all personnel with potential concussive events. There is substantial overlap between post-concussive syndrome and post-traumatic stress disorder, and blast-related mild TBI seems to increase the risk of post-traumatic stress disorder. Post-concussive syndrome, post-traumatic stress disorder, and chronic pain are a clinical triad in this patient group. Persistent impairment after blast-related mild TBI might be largely attributable to psychological factors, although a causative link between repeated mild TBIs caused by blasts and chronic traumatic encephalopathy has not been established. The application of advanced neuroimaging and the identification of specific molecular biomarkers in serum for diagnosis and prognosis are rapidly advancing, and might help to further categorise these injuries. PMID:23884075

Rosenfeld, Jeffrey V; McFarlane, Alexander C; Bragge, Peter; Armonda, Rocco A; Grimes, Jamie B; Ling, Geoffrey S

2013-07-22

272

Paint removal using wheat starch blast media  

Microsoft Academic Search

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

Terry Foster; John Oestreich

1993-01-01

273

Simulation of blast waves with shock tubes  

Microsoft Academic Search

It is shown that quasi-one-dimensional computational techniques can be successfully used to model the flow in large, geometrically complicated shock tubes. Such shock tubes, or blast simulators, can be used to simulate nuclear or conventional explosions by shaping the pressure history. Results from computations show favorable agreement when compared with data taken in a blast simulator facility in Gramat, France.

Andrew Mark

1990-01-01

274

The biology of CML blast crisis  

Microsoft Academic Search

of BCR\\/ABL with genes dysregulated dur- ing disease progression. Most genetic abnormalities of CML blast crisis have a direct or indirect effect on p53 or Rb (or both) gene activity, which are primarily required for cell proliferation and sur- vival, but not differentiation. Thus, the differentiation arrest of CML blast crisis cells is a secondary consequence of these abnormalities or

Bruno Calabretta; Danilo Perrotti

2004-01-01

275

Blast furnace coal injection in China  

SciTech Connect

The development of blast furnace coal injection in China will be summarized. The improvements in the technical process for pneumatic conveying, injection feed control, distribution and combustion of pulverized coal will be covered. Ideas are also described concerning the use of oxy-coal technology in a blast furnace.

Zhou, J.G. (Ministry of Metallurgical Industry, Beijing (China). Central Iron and Steel Research Inst.)

1994-09-01

276

The Biological Effects Of Repeated Blasts.  

National Technical Information Service (NTIS)

The results of investigations on the biological effects of repeated blasts were reviewed. In the present study, sheep and swine were subjected to multiple blasts at a rate of one per minute in a high-explosive-driven shocktube. Three 1% lethal doses (LD1)...

D. R. Richmond E. R. Fletcher J. T. Yelverton

1981-01-01

277

Severe tyre blast injuries during servicing  

Microsoft Academic Search

BackgroundThe destructive potential of the tyre explosions has received little attention in the medical literature. Fatal and severely deforming injuries have been reported. These blasts mainly affect the personnel servicing big vehicle tyres such as trucks and buses. We aimed to review the relevant literature on tyre blast injuries so as to define the mechanism of injury, outcome, and its

Ashraf F. Hefny; Hani O. Eid; Fikri M. Abu-Zidan

2009-01-01

278

PROTECTIVE DESIGNS FOR BLAST AND IMPACT THREATS  

Microsoft Academic Search

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

J. E. Crawford

279

Fragmentation Monitoring of Production Blasts at Mrica,  

National Technical Information Service (NTIS)

The aim of the project was to collect field data regarding blasting, bench geometry and rock structures and to study the influence of these properties on the size distribution of the blasted rock. A conceptual model called SweFrag, for predicting the size...

S. Abrahamsson B. Niklasson F. Ouchterlony

1987-01-01

280

Review of scratch test studies of abrasion mechanisms  

SciTech Connect

The use of scratch tests to simulate the material removal mechanisms which occur during abrasion is reviewed. Although useful studies of the effect of the rake angle on material removal have been carried out using diamond tools, closer simulation of the mechanisms of material removal can be obtained using actual irregular individual abrasive particles as scratch tools. Previous studies are reviewed in which scratch tests have been performed with both conventional scratch test instruments and a specially designed system used for )ital in situ) scratch tests in the scanning electron microscope (SEM). Multiple-pass scratch tests over the same scratch path have been shown to create surface features and wear debris particles which are very similar to those produced by low-stress abrasion. Alumina (Al/sub 2/O/sub 3/) particles have been shown to produce continuous micromachining chips from the hard, brittle carbide phase of Stellite alloys, establishing direct cutting as the important mechanism of material removal for this type of abrasive. An )ital in situ) study of material removal from white cast irons by quartz particles has provided conclusive evidence that carbide removal does not occur by direct cutting but rather always involves microfracture. Previously unpublished work which has compared scratch tests with crushed quartz and alumina particles is included. Also described is a new scratch test system which controls the depth of cut rather than the scratch load in order to simulate high-stress abrasion, in which abrasive particles are constrained to a fixed depth of cut. Preliminary new results show substantially different carbide fracture behavior under fixed-depth conditions. 8 figs., 20 refs.

Kosel, T.H.

1986-01-01

281

Dynamic fragmentation of blast mitigants  

NASA Astrophysics Data System (ADS)

Experimental evidence from a wide range of sources shows that the expanding cloud of explosively disseminated material comprises “particles” or fragments which have different dimensions from those associated with the original material. Powders and liquids have often been used to surround explosives to act as blast mitigants, and this is the main driver for our research. There are also many other areas of interest where an initially intact material surrounding an explosive charge is dynamically fragmented into a distribution of fragment sizes. Examples of such areas include fuel air explosives and enhanced blast explosives as well as quasi-static pressure mitigation systems, and our studies are thus also relevant to these applications. In this paper, we consider the processes occurring as an explosive interacts with a surrounding layer of liquid or powder and identify why it is important to model these processes as a multiphase material problem as opposed to a single phase, single material velocity problem. We shall present results from this class of numerical modelling. In this paper we shall explore what determines the particle or fragment size distribution resulting from explosive dissemination of a layer of material and discuss reasons why clouds from disseminated liquids and powders look similar. We shall support our analysis with results from recent explosives trials and introduce early results from some ongoing small scale explosive mitigation experiments.

Milne, A. M.; Parrish, C.; Worland, I.

2010-02-01

282

Advances in composite machining with abrasive-waterjets  

NASA Astrophysics Data System (ADS)

Abrasive-waterjets are being used in many composite trimming applications. The macro morphology and geometrical features, such as kerf taper or waviness of cuts produced in composites are not different than those observed in other materials. However, depending on the composite structure, micro effects may be significantly different. This paper, an extension of a previously published work, presents new data and observations on linear cutting, turning, drilling, and milling of composites. In general, the abrasive-waterjet is shown to allow accurate control of the machining process; machining accuracies of 0.025 mm have been demonstrated.

Hashish, M.

283

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2013 CFR

...Blasting signs, warnings, and access control. 816.66 Section 816.66...Blasting signs, warnings, and access control. (a) Blasting signs. Blasting...the blasting schedule. (c) Access control. Access within the...

2013-07-01

284

Aspects of blast resistant masonry design  

SciTech Connect

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.

Volkman, D.E.

1989-01-01

285

Microstructural Effects in Abrasive Wear: Final Report for Period September 15, 1981-March 14, 1986.  

National Technical Information Service (NTIS)

This report summarizes research performed on abrasion of metallic alloys. The work was designed to improve our understanding of the factors affecting abrasion rates in two-phase alloys containing large, hard second-phase particles (SPPs) such as carbides,...

T. H. Kosel

1988-01-01

286

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

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 ...SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512âReflectorized Bicycle Wheel Rim Abrasion Test Device...

2010-01-01

287

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

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 ...SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512âReflectorized Bicycle Wheel Rim Abrasion Test Device...

2009-01-01

288

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

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 ...SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512âReflectorized Bicycle Wheel Rim Abrasion Test Device...

2013-01-01

289

Three-body abrasive wear of short glass fibre polyester composite  

Microsoft Academic Search

Short E-glass fibre-reinforced polyester composites with and without filler have been studied for the low stress abrasive wear behaviour carried out using Rubber Wheel Abrasion Test (RWAT) apparatus. In the present investigation, angular silica sand particles of size ranging between 100–200 and 200–300 ?m were used as dry and loose abrasives. The volume loss of the composite during three-body abrasion

Navin Chand; Ajay Naik; Somit Neogi

2000-01-01

290

Ball-cratering abrasion tests of high-Cr white cast irons  

Microsoft Academic Search

The application of a ball-cratering method to test three-body abrasive wear of bulk materials in the presence of large abrasive particles has been investigated. Three high-Cr white cast irons (WCIs) with different material properties were used as wear samples. Abrasive slurries contained two types of abrasive particles, silica sand and crushed quartz. Silica sand and crushed quartz particles have similar

G. B. Stachowiak; G. W. Stachowiak; O. Celliers

2005-01-01

291

Model of the abrasive wear of HVOF deposited Cr3C2-NiCr coating  

Microsoft Academic Search

Based on the abrasive wear theory of composite materials in the condition of equal pressure, the coating microstructure and abrasive wear condition, the model for characterization the abrasive wear behavior of HVOF sprayed Cr3C2-NiCr coating was proposed. By examination of the morphology of the different area of worn surface, this model was confirmed. It is shown the abrasive wear of

Gangchang Ji; Hongtao Wang; Qingyu Chen; Wei Fu; Changjiu Li

2010-01-01

292

Performance of abrasive wear of Cr3C2-NiCr coatings sprayed by HVOF  

Microsoft Academic Search

The abrasive wear behavior of high velocity oxy-fuel (HVOF) sprayed Cr3C2-25%NiCr coatings deposited in different conditions was investigated by wet sand rubber wheel abrasive wear tester using three kinds of abrasives (brown alumina, Jin Gang sand and Hu Kou sand). The abrasive wear mechanism was discussed. The results show that weight loss of HVOF sprayed Cr3C2-25% NiCr coating after worn

Gang-Chang Ji; Hong-Tao Wang; Qing-Yu Chen; Wei Fu; Jie-Guang Song; Can-Hui He; Si-De Huang

2010-01-01

293

Study of Micro Abrasive Tool Making by Pulse Plating Using Taguchi Method  

Microsoft Academic Search

Experimental investigation of pulse plating parameters on the extent of incorporation of micro diamond abrasives within metallic binder was performed for a micro abrasive tool. The Taguchi experimental design has been applied to investigate the optimal combination of process parameters to achieve embedment of nominal amount of abrasives in the nickel bond matrix. Analysis of variance was performed and signal-to-noise

Anuj Dabholkar; Murali M. Sundaram

2012-01-01

294

PENETRATION ABILITY OF ABRASIVE WATERJETS IN CUTTING OF ALUMINUM-SILICON CARBIDE PARTICULATE METAL MATRIX COMPOSITES  

Microsoft Academic Search

This article presents a set of studies performed on aluminum-silicon carbide particulate metal matrix composites prepared by adding 5, 10, 15 and 20% of SiC in aluminum alloy and processed with abrasive water jets that are formed with garnet and silicon carbide abrasives of 80 mesh size. These studies are essentially meant to assess the penetration ability of abrasive water

S. Srinivas; N. Ramesh Babu

2012-01-01

295

Evaluation of abrasive wear of ductile cast iron in a single pass pendulum device  

Microsoft Academic Search

The abrasive wear resistance of ductile cast iron with different matrix microstructures (ferrite, pearlite, bainite and martensite) was studied under instrumented single-pass pendulum sclerometry testing. This technique uses only one abrasive particle with known geometry and the abrasive wear event can be isolated, providing fundamental information on the interaction between the particle and the material. The testing conditions selected were

Juan Manuel Vélez; D. K. Tanaka; A. Sinatora; A. P. Tschiptschin

2001-01-01

296

Prediction system of magnetic abrasive finishing (MAF) on the internal surface of cylindrical tube  

Microsoft Academic Search

This study mainly used the way of the magnetic abrasive finishing (MAF) to explore the cylindrical tube of stainless steel SUS304 related to the processing characteristic and the prediction system. The self-make adjustable electricity polishing mechanism was assembled on the magnetic abrasive machine. The magnetic abrasive which was consisted of the sintered iron and Aluminum Oxide powder filled in the

Ching-Lien Hung; Wei-Liang Ku; Lieh-Dai Yang; Han-Ming Chow

2010-01-01

297

Modeling and simulation of surface roughness in magnetorheological abrasive flow finishing (MRAFF) process  

Microsoft Academic Search

Magnetorheological abrasive flow finishing (MRAFF) process was developed for super finishing of internal geometries of hard materials. This process relies for its performance on magnetorheological effect exhibited by carbonyl iron particles along with abrasive particles in non-magnetic viscoplastic base medium. The extent of finishing action depends on radial and tangential forces coming on abrasive particles due to carbonyl iron particles

Sunil Jha; V. K. Jain

2006-01-01

298

Mechanism of Surface Finishing in Ultrasonic-Assisted Magnetic Abrasive Finishing Process  

Microsoft Academic Search

Ultrasonic-assisted magnetic abrasive finishing (UAMAF) integrates the use of ultrasonic vibrations and magnetic abrasive finishing (MAF) processes to finish surfaces of nanometer order within a minute's time. The present study emphasizes the mechanism of surface finishing in UAMAF. This article reports the study of the microscopic changes in the surface texture resulting from interaction of abrasives with ground workpiece surface.

Rahul S. Mulik; Pulak M. Pandey

2010-01-01

299

Design and development of the magnetorheological abrasive flow finishing (MRAFF) process  

Microsoft Academic Search

A new precision finishing process for complex internal geometries using smart magnetorheological polishing fluid is developed. Magnetorheological abrasive flow finishing (MRAFF) process provides better control over rheological properties of abrasive laden magnetorheological finishing medium. Magnetorheological (MR) polishing fluid comprises of carbonyl iron powder and silicon carbide abrasives dispersed in the viscoplastic base of grease and mineral oil; it exhibits change

Sunil Jha; V. K. Jain

2004-01-01

300

Characteristics of the surface of a titanium alloy following milling with abrasive waterjets  

Microsoft Academic Search

Abrasive waterjets have been used for many years for the cutting of materials. Abrasive particles are entrained into a rapidly moving jet of water which impinges onto a substrate. Material is removed by erosion processes and the jet fully penetrates the material being cut in a single pass. More recently, abrasive waterjets have been employed for the machining of materials

P. H. Shipway; G. Fowler; I. R. Pashby

2005-01-01

301

Chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model.  

PubMed

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

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

2012-05-16

302

Sliding and abrasive wear behaviour of boride coatings  

Microsoft Academic Search

Polyphase boride coatings constituted by an inner layer of Fe2B and an outer layer of FeB were thermochemically grown on iron and medium carbon steel by a pack cementation process. The tribological behaviour of borided samples was investigated under both sliding and abrasion testing conditions. Considerably different values of wear rate were found in different regions of the coatings. The

C. Martini; G. Palombarini; G. Poli; D. Prandstraller

2004-01-01

303

Abrasion of Concrete by Ice in Arctic Sea Structures.  

National Technical Information Service (NTIS)

In arctic sea regions a concrete sea structure is subjected to heavy mechanical loads near the water level due to the moving ice sheets. The determination of the abrasion depth is based on laboratory tests for measuring ice pressures against protruding ag...

S. Huovinen

1990-01-01

304

Iatrogenic tooth abrasion comparisons among composite materials and finishing techniques  

Microsoft Academic Search

Statement of Problem. Many different rotary instruments are available for shaping composite restorations. Whether use of these instruments causes undesirable iatrogenic abrasion of either the tooth surface or the composite restorative material is unknown. Assuming that damage occurs, which technique is least damaging is unknown. Purpose. This in vitro study quantified the loss of surface enamel and dentin surrounding Class

Christina A. Mitchell; Maria R. Pintado; William H. Douglas

2002-01-01

305

29 CFR 1926.303 - Abrasive wheels and tools.  

Code of Federal Regulations, 2010 CFR

...be used; (ii) When wheels 2 inches or less in diameter...securely mounted on the end of a steel mandrel are...4) Portable abrasive wheels used for internal grinding...securely mounted on the end of a steel mandrel are used; (ii) If the wheel is entirely within...

2009-07-01

306

29 CFR 1926.303 - Abrasive wheels and tools.  

Code of Federal Regulations, 2010 CFR

...be used; (ii) When wheels 2 inches or less in diameter...securely mounted on the end of a steel mandrel are...4) Portable abrasive wheels used for internal grinding...securely mounted on the end of a steel mandrel are used; (ii) If the wheel is entirely within...

2010-07-01

307

Mechanochemistry of metal polishing with an abrasive suspension  

Microsoft Academic Search

Conditions in which the mechanism of precision polishing, based on controlled oxidation of the metal surface and mechanical\\u000a removal of the oxidation products with an abrasive suspension in its shear deformation by a polishing instrument, can be implemented\\u000a are considered.

E. E. Bibik

2010-01-01

308

FURTHER RESEARCH OF ABRASIVE WEAR BEHAVIOUR OF ENGINEERING POLYMERS  

Microsoft Academic Search

To improve the abrasive wear behaviour of a certain tribo system - modifying the system -, there are more keys e.g. replacing the metal surface with a plastic one. If in a given tribo system the engineering plastic part can be acceptable from other engineering points (e.g. strength, life period and fatigue) than the proper plastic selection may improve the

Kalácska Gábor; Zsidai László; Bors Zoltán; Fenyvesi László; Eberst Ottó; Pop Sever

309

Self-adjusting abrasiveness: a new technology for prophylaxis pastes.  

PubMed

An ideal prophylaxis paste should have both cleaning and polishing properties. Key elements would be abrasive particles that become less aggressive under load. The abrasive perlite, a volcanic glass with a sheetlike geometry, is claimed to have these unique properties. This study evaluated the average particle size, size distribution, and morphology of perlite in raw form, in an unused prophylaxis paste, and a used prophylaxis paste. The surface roughness induced on enamel and dentinal specimens was quantitated after paste application in either a rubber cup or a nylon brush. Flour of pumice, a standard prophylaxis paste, a polishing paste, and water were tested similarly. The luster induced by the tested pastes and controls was assessed. Perlite blunted and disintegrated under load. The perlite-containing prophylaxis paste acted as a fine or superfine prophylaxis paste, although it was ranked as medium, based on the mean particle size of its abrasive in the fresh, unused form. Perlite might provide the properties required for the abrasive material of an ideal prophylaxis paste. PMID:8390065

Lutz, F; Sener, B; Imfeld, T; Barbakow, F; Schüpbach, P

1993-01-01

310

A nonmineralized approach to abrasion-resistant biomaterials.  

PubMed

The tooth-like mouthparts of some animals consist of biomacromolecular scaffolds with few mineral components, making them intriguing paradigms of biostructural materials. In this study, the abrasion resistance of the jaws of one such animal, the bloodworm Glycera dibranchiata, has been evaluated by nanoindentation, nanoscratching, and wear testing. The hardest, stiffest, and most abrasion-resistant materials are found within a thin (<3 microm) surface layer near the jaw tip and a thicker (10-20 microm) subsurface layer, both rich in unmineralized Cu. These results are consistent with the supposition that Cu ions are involved in the formation of intermolecular coordination complexes between proteins, creating a highly cross-linked molecular network. The intervening layer contains aligned atacamite [Cu(2)(OH)(3)Cl] fibers and exhibits hardness and stiffness (transverse to the alignment direction) that are only slightly higher than those of the bulk material but lower than those of the two Cu-rich layers. Furthermore, the atacamite-containing layer is the least abrasion-resistant, by a factor of approximately 3, even relative to the bulk material. These observations are broadly consistent with the behavior of engineering polymer composites with hard fiber or particulate reinforcements. The alignment of fibers parallel to the jaw surface, and the fiber proximity to the surface, are both suggestive of a natural adaptation to enhance bending stiffness and strength rather than to endow the surface regions with enhanced abrasion resistance. PMID:17702868

Pontin, Michael G; Moses, Dana N; Waite, J Herbert; Zok, Frank W

2007-08-16

311

Innovative decontamination technology by abrasion in vibratory vessels  

SciTech Connect

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)

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

2007-07-01

312

Soviet abrasive polishing compositions for precision photocopy blanks  

Microsoft Academic Search

. The purpose of our paper was to investigate the properties of aqueous suspensions of abrasive powders based on cerium dioxide, produced by different methods. Complex physicochemical processes occur on the surface of a glass plate during polishing. The rate of removal of the material and the quality of the glass blanks are determined not only by the hardness of

L. N. Shevyakova; A. M. Mazin; R. A. Rodionov; B. G. Gribov

1982-01-01

313

Mechanical Removal in CMP of Copper Using Alumina Abrasives  

Microsoft Academic Search

Results from experiments on the removal of copper using chemical mechanical polishing ~CMP! by alumina abrasives suspended in deionized water are reported. The experiments were carried out in a benchtop polishing tool using IC1000 perforated pads and SUBA 500 pads. The removal rate was measured over a good range of values of the relative velocity and pressure, and for different

Lirong Guo; R. Shankar Subramanianz

2004-01-01

314

Abrasion and impact properties of partially chilled ductile iron  

Microsoft Academic Search

This paper reports the results of laboratory tests carried out to evaluate the abrasion wear resistance and impact properties of partially chilled ductile iron (PCDI). The versatility of the casting process allows the use of coolers (commonly referred as chills) at specified locations in the mold, in order to increase the solidification rate and in consequence, obtain a high carbide

B. A Ceccarelli; R. C Dommarco; R. A Mart??nez; M. R Mart??nez Gamba

2004-01-01

315

A neural network process model for abrasive flow machining operations  

Microsoft Academic Search

This paper describes the development of a predictive process modeling system for the abrasive flow machining (AFM) process. This process is used for polishing and surface removal of workpieces with an internal flow path. The core of the process modeling system is a set of neural network models that predicts surface finish and dimensional change. These neural network models are

Kimberly L. Petri; Richard E. Billo; Bopaya Bidanda

1998-01-01

316

Modelling of abrasive flow machining process: a neural network approach  

Microsoft Academic Search

A simple neural network model for abrasive flow machining process has been established. The effects of machining parameters on material removal rate and surface finish have been experimentally analysed. Based on this analysis, model inputs and outputs were chosen and off-line model training using back-propagation algorithm was carried out. Simulation results confirm the feasibility of this approach and show a

R. K. Jain; V. K. Jain; P. K. Kalra

1999-01-01

317

Statistical Analysis of Magnetic Abrasive Finishing (MAF) On Surface Roughness  

Microsoft Academic Search

Magnetic assisted finishing is one of the nontraditional methods of polishing that recently has been attractive for the researchers. This paper investigates the effects of some parameters such as rotational speed of the permanent magnetic pole, work gap between the permanent pole and the work piece, number of the cycles and the weight of the abrasive particles on aluminum surface

Mehrdad Givi; Alireza Fadaei Tehrani; Aminollah Mohammadi

2010-01-01

318

Investigations into abrasive flow finishing of complex workpieces using FEM  

Microsoft Academic Search

Abrasive flow machining (AFM) process provides a high level of surface finish and close tolerances with an economically acceptable rate of surface generation for a wide range of industrial components. It is attempted to analyze the AFM process using finite element method (FEM) for finishing of external surfaces. To study the material removal mechanism of AFM, finite element model of

V. K. Jain; Rajani Kumar; P. M. Dixit; Ajay Sidpara

2009-01-01

319

Metastable austenitic stainless steel tool for magnetic abrasive finishing  

Microsoft Academic Search

Through selective heat treatment, a metastable austenitic stainless steel tool can be fabricated to exhibit alternating magnetic and nonmagnetic regions. Magnetic abrasive is attracted to the borders of the magnetic regions of the developed tool to create additional finishing points. In combination with a multiple pole-tip system, this unique magnetic property facilitates simultaneous finishing of multiple regions for shortening finishing

H. Yamaguchi; J. Kang; F. Hashimoto

2011-01-01

320

Effective Deburring of Micro Burr Using Magnetic Abrasive Finishing Method  

Microsoft Academic Search

Micro burrs formed in micro parts are not subject to be removed by the conventional deburring method for marco parts. Magnetic abrasive deburring method which was proved to be effective for small burrs are applied for deburring the micro burr in electric gun parts used in TV monitor. A specific magnetic inductor is designed and manufactured for this part. To

Jung Il Park; S.-L. Ko; Y. H. Hanh; Yuri M. Baron

2005-01-01

321

The management of corneal abrasions in accident and emergency.  

PubMed

Recent debate over the use of eyepads and mydriatics for corneal abrasions in ophthalmology departments (Mindin et al., 1996, JAMA 1996; 27: 837) has prompted this review of the management of small corneal abrasions (< 60% of cornea) in a large teaching hospital accident and emergency (A&E) department. Ninety-nine patients were studied who presented to the Leicester Royal Infirmary A&E Department with a corneal abrasion; 49 were given an eye pad and 50 were not given an eye pad. All patients received chloramphenicol (1%) ointment. There was no significance difference between the two groups in terms of the duration of pain (p > 0.2). Four patients developed corneal infections (two wore an eyepad, two had no eye pad). There was only one patient who suffered a transient but significant reduction in visual acuity (6/9-6/18), following the use of an eye pad and subsequent diagnosis in eye casualty of a dendritic ulcer. It is concluded that accident and emergency treatment of small corneal abrasions is safe and effective if an eye pad is not given. Previous criticisms of A&E management of eye problems (Nayeen and Stansfield, Archs Emerg Med, 1992; 9: 257) are unfounded in this department. PMID:9616389

Hart, A; White, S; Conboy, P; Quinton, D

1997-10-01

322

Characterization and prediction of abrasive wear of powder composite materials  

Microsoft Academic Search

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

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

2009-01-01

323

Abrasive waterjet peening with elastic prestress: A parametric evaluation  

Microsoft Academic Search

Abrasive waterjet peening (AWJP) has emerged as a potentially viable method of surface treatment for metal orthopedic devices. In this study the influences of AWJP with elastic prestress on the surface and subsurface residual stress distributions and surface texture of spring steel (ASTM 228) as well as titanium (Ti6Al4V) and nickel (inconel 718) alloys were studied. A design of experiments

B. Sadasivam; A. Hizal; D. Arola

2009-01-01

324

Blast investigation by fast multispectral radiometric analysis  

NASA Astrophysics Data System (ADS)

Knowledge regarding the processes involved in blasts and detonations is required in various applications, e.g. missile interception, blasts of high-explosive materials, final ballistics and IED identification. Blasts release large amount of energy in short time duration. Some part of this energy is released as intense radiation in the optical spectral bands. This paper proposes to measure the blast radiation by a fast multispectral radiometer. The measurement is made, simultaneously, in appropriately chosen spectral bands. These spectral bands provide extensive information on the physical and chemical processes that govern the blast through the time-dependence of the molecular and aerosol contributions to the detonation products. Multi-spectral blast measurements are performed in the visible, SWIR and MWIR spectral bands. Analysis of the cross-correlation between the measured multi-spectral signals gives the time dependence of the temperature, aerosol and gas composition of the blast. Farther analysis of the development of these quantities in time may indicate on the order of the detonation and amount and type of explosive materials. Examples of analysis of measured explosions are presented to demonstrate the power of the suggested fast multispectral radiometric analysis approach.

Devir, A. D.; Bushlin, Y.; Mendelewicz, I.; Lessin, A. B.; Engel, M.

2011-05-01

325

Acceleration of Ungapped Extension in Mercury BLAST  

PubMed Central

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.

Buhler, Jeremy; Chamberlain, Roger D.

2007-01-01

326

LTC vacuum blasting machine (concrete): Baseline report  

SciTech Connect

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.

NONE

1997-07-31

327

30 CFR 75.1320 - Multiple-shot blasting.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Multiple-shot blasting. 75.1320 Section 75.1320...and Blasting § 75.1320 Multiple-shot blasting. (a) No more than 20 boreholes...blasting cut coalâ (i) The first shot or shots fired in a round shall be...

2009-07-01

328

30 CFR 75.1320 - Multiple-shot blasting.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Multiple-shot blasting. 75.1320 Section 75.1320...and Blasting § 75.1320 Multiple-shot blasting. (a) No more than 20 boreholes...blasting cut coalâ (i) The first shot or shots fired in a round shall be...

2010-07-01

329

Analysis of magnetic abrasive finishing with slotted magnetic pole  

NASA Astrophysics Data System (ADS)

Magnetic Abrasive Finishing (MAF) is relatively a new finishing process among the advanced finishing processes in which the workpiece is kept in the magnetic field created by two poles of an electromagnet. The working gap between the workpiece and the magnet is filled with magnetic abrasive particles. A flexible magnetic abrasive brush is formed, acting as a multipoint cutting tool, due to the effect of magnetic field in the working gap. This process is capable of producing the surface finish of nanometer range. Most of the researchers have been using the electromagnet having a slot in it to improve the performance of the process but hardly any information is available about its effect on the process performance. This paper deals with the effect of a slot made in the electromagnet on the forces and surface quality during MAF. An experimental set-up is designed and fabricated for the measurement of the magnetic field distribution in the working gap. The magnetic field is simulated using a finite element model of the process. The magnetic field is also measured experimentally to validate the theoretical results. It indicates a good agreement between the experimental results and simulated values. The finite element method is further used for the evaluation of the magnetic force and surface quality during MAF. To our surprise it is found that the force under the slot is negative, even then process performance is improved. MAF process removes a very small amount of material by indentation and rotation of the magnetic abrasive particles in the circular tracks. Due to rotation of the magnetic abrasive flexible brush, grooves are formed on the workpiece surface which decides the surface profile after MAF. Surface quality is determined on the basis of the surface profile achieved by equating the volume of groove produced. These results show an improvement in finishing rate while using a slotted pole surface.

Jayswal, S. C.; Jain, V. K.; Dixit, P. M.

2004-06-01

330

Blast-induced mild traumatic brain injury.  

PubMed

Traumatic brain injury (TBI) has been a major cause of mortality and morbidity in the wars in Iraq and Afghanistan. Blast exposure has been the most common cause of TBI, occurring through multiple mechanisms. What is less clear is whether the primary blast wave causes brain damage through mechanisms that are distinct from those common in civilian TBI and whether multiple exposures to low-level blast can lead to long-term sequelae. Complicating TBI in soldiers is the high prevalence of posttraumatic stress disorder. At present, the relationship is unclear. Resolution of these issues will affect both treatment strategies and strategies for the protection of troops in the field. PMID:21093677

Elder, Gregory A; Mitsis, Effie M; Ahlers, Stephen T; Cristian, Adrian

2010-10-15

331

Partnering and the WCI blast furnace reline  

SciTech Connect

In 1993, WCI Steel entered into a partnership agreement to perform a blast furnace reline. The reline included a complete rebrick from the tuyere breast to the furnace top including the tapholes. Also included was the replacement of the Paul Wurth top equipment from the receiving hoppers through the gearbox and distribution chute, a skip incline replacement, and installation of tilting runners and a casthouse roof. The bustle pipe and hot blast main were repaired. One stove was also replaced. The reline was accomplished in 36 days, wind to wind, which allowed for 29 days of construction inside the blast furnace proper.

Musolf, D.W. [WCI Steel, Inc., Warren, OH (United States)

1997-11-01

332

CO{sub 2} pellet blasting studies  

SciTech Connect

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.

Archibald, K.E.

1997-01-01

333

Study on the characteristics of Magneto-Electrolytic-Abrasive Polishing by using the newly developed nonwoven-abrasive pads  

Microsoft Academic Search

Recently, advanced technologies in general industry demand that the production of precision parts is much more precise and efficient. However, most of the precision finishing technologies cannot satisfy both the finishing efficiency and surface finishing at the same time. Magneto-Electrolytic-Abrasive Polishing (MEAP) is a new ultra precision machining technology, which combined many kinds of energy, has been deeply investigated under

Jeong-Du Kim; Yan-Meng Xu; Youn-Hee Kang

1998-01-01

334

Factors influencing the abrasion resistance of thin-film magnetic media  

NASA Astrophysics Data System (ADS)

Abrasion testing was performed on direct current (DC) hydrogenated carbon films on commercial thin-film disks processed under several conditions. Four film characteristics were found to influence the abrasion resistance of the disk, i.e., roughness, film adhesion, carbon toughness, and coefficient of friction. It was found that both fine-scale surface topography from the sputtered layer and substrate texture degraded abrasion resistance. Excellent abrasion resistance was observed for carbon films as thin as 10 nm on polished substrates when the magnetic film topography was minimized. Film adhesion was degraded by exposure to temperature and humidity. Hydrogen incorporation into the carbon films reduced film hardness which degraded abrasion resistance.

Schulz, K. J.; Viswanathan, K. V.

1994-07-01

335

Effect of the Blasting Angle on Blast Processing of a Cylindrical Surface  

NASA Astrophysics Data System (ADS)

Blast processing is a substrate processing technique during which spherical or granular materials are jetted against the substrate surface using compressed air. Blasting techniques is widely used for various mechanical parts as a surface reforming technique. When performing blast processing to a complicated-shaped substrate for the purpose of thermal spraying method, it is difficult to set blasting angle to a constant value and it is necessary to clarify the effect of state of substrate on blast processing. In present paper, the effect of blasting angle to removal processing effect and the modification state of substrate is investigated. Results from this investigation are summarized as follows: When blasting angle ? was 30º, the removal quantity ? showed the maximum. The removal quantity became large as cylindrical diameter D was larger. Removal quantity of particle diameter a =100 ?m is bigger than that of a =700 ?m. As a nozzle movement rate v increased, removal quantity ? became small. As blasting angle ? became small, removal quantity ? became large even though nozzle movement rate v was changed. As blasting pressure P increases, removal quantity ? became big.

Kubohori, Toshifumi; Binti Khalil, Nur Zalikha; Tojo, Yuichi; Takahashi, Shigetaka

336

Primary blast injuries--an updated concise review.  

PubMed

Blast injuries have been increasing in the civilian setting and clinicians need to understand the spectrum of injury and management strategies. Multisystem trauma associated with combined blunt and penetrating injuries is the rule. Explosions in closed spaces increase the likelihood of primary blast injury. Rupture of tympanic membranes is an inaccurate marker for severe primary blast injury. Blast lung injury manifests early and should be managed with lung-protective ventilation. Blast brain injury is more common than previously appreciated. PMID:22411082

Yeh, Daniel Dante; Schecter, William P

2012-05-01

337

Plastic Media Blasting Recycling Equipment Study.  

National Technical Information Service (NTIS)

Plastic Media Blasting (PMB) is a new technology introduced as a candidate to replace wet chemical paint stripping of airframes and component parts. This report documents the physical testing, observations, and laboratory analyses used to evaluate the eff...

1988-01-01

338

Plastic Media Blasting (PMB) waste treatment technology.  

National Technical Information Service (NTIS)

Environmental and occupational hazard regulations have motivated consideration of several new developments in paint removal technology. Plastic Media Blasting (PMB)/paint wastes consist predominantly of degraded plastic media plus the stripped paint. They...

H. Jermyn R. P. Wichner

1991-01-01

339

Material Systems for Blast-Energy Dissipation  

SciTech Connect

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.

James Schondel; Henry S. Chu

2010-10-01

340

BLAST FURNACE GRANULAR COAL INJECTION SYSTEM  

SciTech Connect

Bethlehem Steel Corporation (BSC) requested financial assistance from the Department of Energy (DOE), for the design, construction and operation of a 2,800-ton-per-day blast furnace granulated coal injection (BFGCI) system for two existing iron-making blast furnaces. The blast furnaces are located at BSC's facilities in Burns Harbor, Indiana. The demonstration project proposal was selected by the DOE and awarded to Bethlehem in November 1990. The design of the project was completed in December 1993 and construction was completed in January 1995. The equipment startup period continued to November 1995 at which time the operating and testing program began. The blast furnace test program with different injected coals was completed in December 1998.

Unknown

1999-10-01

341

Nucleon and Deuteron Form Factors from BLAST  

NASA Astrophysics Data System (ADS)

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.

Hasell, D. K.

2009-12-01

342

Materials Evaluations in an Experimental Blast Furnace.  

National Technical Information Service (NTIS)

Seven evaluation tests with blast furnace iron-bearing burden materials are described. The effects of pellet strength, fines in the burden, decreasing slag volume, pellet size, eliminating stone with superfluxed sinter, and eliminating stone by prefluxing...

P. L. Woolf

1984-01-01

343

Blast Trauma: The Effects on Hearing.  

National Technical Information Service (NTIS)

This project will determine what effects impulse noise (blast trauma) has on hearing performance, the response patterns of auditory nerve fibers and the morphology of cochlea. Initially, audiograms and psychophysical tuning curves of the normal chinchilla...

R. P. Hamernik D. Henderson R. Salvi

1981-01-01

344

Improvement of Blasting Techniques in Opencast Mines.  

National Technical Information Service (NTIS)

Experience to date indicates that the most important factors affecting the degree of blasting required are the homogeneity of the hard rocks and their overall thickness, taken together with the amount of regional jointing, stratification fractures and ind...

1987-01-01

345

An upgraded data-acquisition system for the balloon-borne liquid xenon gamma-ray imaging telescope LXeGRIT  

Microsoft Academic Search

LXeGRIT is a balloon-borne Compton telescope for MeV gamma-ray astrophysics, based on a liquid xenon time projection chamber (LXe-TPC) with charge and light readout. The first balloon flights in 1997 revealed limitations of the trigger electronics and the data acquisition (DAQ) system, leading to their upgrade. New electronics was developed to handle the xenon scintillation light trigger. The original processor

E. Aprile; A. Curioni; K.-L. Giboni; U. Oberlack; S. Ventura

2001-01-01

346

Observation of 1-10 MeV Gamma-Rays from the Crab with the Balloon-Borne LXeGRIT Compton Telescope  

Microsoft Academic Search

The balloon-borne LXeGRIT is the first prototype of a novel Compton telescope based on a high resolution 3-D imaging time projection chamber (TPC). The ionization detector, triggered by the fast Xe scintillation light, measures the three spatial coordinates and the energy deposited by each gamma-ray interaction in its active volume of 2800 cm3 of pure liquid Xenon. As a calorimeter,

E. Aprile; A. Curioni; K.-L. Giboni; M. Kobayashi; U. G. Oberlack; E. L. Chupp; P. P. Dunphy; S. Ventura; T. Doke; J. Kikuchi

2003-01-01

347

Fabrication of microstructures by powder blasting  

Microsoft Academic Search

This thesis deals with the use of powder blasting as a micromachining\\u000atechnique to create micro systems. Powder blasting is a technology in\\u000awhich small particles, accelerated by an air jet, are directed towards a\\u000abrittle target for mechanical material removal. It is especially useful for\\u000aglass machining due to the limitations of other glass micromachining\\u000atechniques.\\u000aParticle jets have

Hendrik Wensink

2002-01-01

348

Creating successful blast furnace refractory systems  

SciTech Connect

Successful lifetimes of the refractories utilized in the blast furnace are dependent on a variety of external factors such as operation, geometry, cooling capability, configuration and arrangement, as well as refractory properties. These external factors, as well as the properties required to withstand the main mechanisms of wear, combine to create the successful refractory system. These significant factors and properties are reviewed with the intention of providing guidelines required for successful refractory performance in the blast furnace.

Dzermejko, A.J. [UCAR Carbon Co., Inc., Columbia, TN (United States)

1995-07-01

349

Pion Electroproduction from Deuterium at BLAST  

NASA Astrophysics Data System (ADS)

The latest pion electroproduction results from the BLAST (Bates Large Acceptance Spectrometer Toroid) experiment at the MIT-Bates Linear Accelerator Center are presented. The experiment used the BLAST detector, a longitudinally polarized electron beam at 850 MeV, and internal targets of polarized hydrogen and vector and tensor polarized deuterium. Event selection and particle identification will be discussed. The measured asymmetries for exclusive pion electroproduction from deuterium will be presented and compared with results obtained from hydrogen and available theoretical predictions.

Shinozaki, Aki

2007-04-01

350

Blast injuries: mechanics and wounding patterns.  

PubMed

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

Covey, Dana C; Born, Christopher T

2010-01-01

351

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.

352

Wind tunnel measurements of adobe abrasion by blown sand: profile characteristics in relation to wind velocity and sand flux  

Microsoft Academic Search

Blown sand causes various damages, such as extensive abrasion to crops, structural wear of facilities and buildings, and abrasion of soil clods and clayey materials generating fine particulate matter. In this study, experiments conducted in a straight-line blowing wind tunnel confirmed field observations and provided useful information for understanding abrasion profiles created by sand drift. Abrasion rates of 20 adobe

Liu Lian-You; Gao Shang-Yu; Shi Pei-Jun; Li Xiao-Yan; Dong Zhi-Bao

2003-01-01

353

Neuropathology of explosive blast traumatic brain injury.  

PubMed

During the conflicts of the Global War on Terror, which are Operation Enduring Freedom (OEF) in Afghanistan and Operation Iraqi Freedom (OIF), there have been over a quarter of a million diagnosed cases of traumatic brain injury (TBI). The vast majority are due to explosive blast. Although explosive blast TBI (bTBI) shares many clinical features with closed head TBI (cTBI) and penetrating TBI (pTBI), it has unique features, such as early cerebral edema and prolonged cerebral vasospasm. Evolving work suggests that diffuse axonal injury (DAI) seen following explosive blast exposure is different than DAI from focal impact injury. These unique features support the notion that bTBI is a separate and distinct form of TBI. This review summarizes the current state of knowledge pertaining to bTBI. Areas of discussion are: the physics of explosive blast generation, blast wave interaction with the bony calvarium and brain tissue, gross tissue pathophysiology, regional brain injury, and cellular and molecular mechanisms of explosive blast neurotrauma. PMID:22836523

Magnuson, John; Leonessa, Fabio; Ling, Geoffrey S F

2012-10-01

354

Ultra Safe And Secure Blasting System  

SciTech Connect

The Ultra is a blasting system that is designed for special applications where the risk and consequences of unauthorized demolition or blasting are so great that the use of an extraordinarily safe and secure blasting system is justified. Such a blasting system would be connected and logically welded together through digital code-linking as part of the blasting system set-up and initialization process. The Ultra's security is so robust that it will defeat the people who designed and built the components in any attempt at unauthorized detonation. Anyone attempting to gain unauthorized control of the system by substituting components or tapping into communications lines will be thwarted in their inability to provide encrypted authentication. Authentication occurs through the use of codes that are generated by the system during initialization code-linking and the codes remain unknown to anyone, including the authorized operator. Once code-linked, a closed system has been created. The system requires all components connected as they were during initialization as well as a unique code entered by the operator for function and blasting.

Hart, M M

2009-07-27

355

Effects of mine blasting on residential structures  

SciTech Connect

Blasting is common in the coal industry to remove rock overburden so that the exposed coal can be mechanically excavated. The ground vibrations and air blast produced by blasting are often felt by residents surrounding the mines. There has been a trend for regulatory authorities, especially those concerned with the environment, to impose low limits on blast vibration levels in response to community pressure, based on human perception and response to vibration. This paper reports the findings of an extensive study on a house which was located adjacent to a coal mine. The house was monitored for over 1 year and was subjected to ground peak particle velocity (PPV) ranging from 1.5 to 222 mm/s. The house was instrumented with accelerometers to measure its dynamic response due to blasting and it was also monitored for cracks before and after each blast. Based on this study, ground motion amplifications along the height of the structure have been established. A simplified methodology presented in this paper has been used to estimate the ground PPV at which cracking is likely.

Gad, E.F.; Wilson, J.L.; Moore, A.J.; Richards, A.B. [Swinburne University of Technology, Hawthorn, Vic. (Australia). Faculty of Engineering & Industrial Science

2005-08-01

356

Neuro-glial and systemic mechanisms of pathological responses in rat models of primary blast overpressure compared to "composite" blast.  

PubMed

A number of experimental models of blast brain injury have been implemented in rodents and larger animals. However, the variety of blast sources and the complexity of blast wave biophysics have made data on injury mechanisms and biomarkers difficult to analyze and compare. Recently, we showed the importance of rat position toward blast generated by an external shock tube. In this study, we further characterized blast producing moderate traumatic brain injury and defined "composite" blast and primary blast exposure set-ups. Schlieren optics visualized interaction between the head and a shock wave generated by external shock tube, revealing strong head acceleration upon positioning the rat on-axis with the shock tube (composite blast), but negligible skull movement upon peak overpressure exposure off-axis (primary blast). Brain injury signatures of a primary blast hitting the frontal head were assessed and compared to damage produced by composite blast. Low to negligible levels of neurodegeneration were found following primary blast compared to composite blast by silver staining. However, persistent gliosis in hippocampus and accumulation of GFAP/CNPase in circulation was detected after both primary and composite blast. Also, markers of vascular/endothelial inflammation integrin alpha/beta, soluble intercellular adhesion molecule-1, and L-selectin along with neurotrophic factor nerve growth factor-beta were increased in serum within 6?h post-blasts and persisted for 7?days thereafter. In contrast, systemic IL-1, IL-10, fractalkine, neuroendocrine peptide Orexin A, and VEGF receptor Neuropilin-2 (NRP-2) were raised predominantly after primary blast exposure. In conclusion, biomarkers of major pathological pathways were elevated at all blast set-ups. The most significant and persistent changes in neuro-glial markers were found after composite blast, while primary blast instigated prominent systemic cytokine/chemokine, Orexin A, and Neuropilin-2 release, particularly when primary blast impacted rats with unprotected body. PMID:22403567

Svetlov, Stanislav I; Prima, Victor; Glushakova, Olena; Svetlov, Artem; Kirk, Daniel R; Gutierrez, Hector; Serebruany, Victor L; Curley, Kenneth C; Wang, Kevin K W; Hayes, Ronald L

2012-02-09

357

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

SciTech Connect

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)

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

358

Proper bit design improves penetration rate in abrasive horizontal wells  

SciTech Connect

Overall drilling penetration rates nearly tripled, and drill bit life nearly doubled compared to conventional bits when specially designed natural diamond and polycrystalline diamond compact (PDC) bits were used during a seven-well horizontal drilling program. The improvement in drilling performance from better-designed bits lowered drilling costs at ANR Pipeline Co.'s Reed City gas storage field in Michigan. Laboratory tests with scaled down bits used on abrasive cores helped determine the optimum design for drilling the gas storage wells. The laboratory test results and actual field data were used to develop a matrix-body natural diamond bit, which was later modified to become a matrix-body, blade-type polycrystalline diamond compact bit. This bit had excellent penetration rates and abrasion resistance. The paper describes the background to the project, bit selection, natural diamond bits, field results, new bit designs, and field results from the new design.

Gentges, R.J. (ANR Pipeline Co., Detroit, MI (United States))

1993-08-09

359

The worn dentition--pathognomonic patterns of abrasion and erosion.  

PubMed

Historically, the dental literature has revealed various causes of tooth wear, yet it has failed to provide a conclusive method of differentiation and diagnosis of the condition. The categories of tooth wear encountered most commonly in dental practice are abrasion and erosion. The major causes of wear from abrasion are bruxism and toothpaste abuse, and the major causes of wear from erosion are regurgitation, coke-swishing and fruit-mulling. Through in-depth clinical study of these causes, this paper provides a diagnostic system that will enable dental professionals to determine and differentiate the exact aetiology of the worn dentition simply by the recognition of the pathognomonic wear patterns on diagnostic casts, which are based upon the position and quantity of the non-carious loss of tooth structure. PMID:16167605

Abrahamsen, Thomas C

2005-01-01

360

Abrasive-waterjet machining of ceramic-coated materials  

NASA Astrophysics Data System (ADS)

This paper addresses an experimental investigation on the feasibility of using abrasive-waterjets (AWJs) for the precision drilling of small-diameter holes in advanced aircraft engine components. These components are sprayed with ceramic thermal barrier coating (TBC), and the required holes are typically 0.025 inch in diameter, with a drilling angle of 25 deg. The parameters of the AWJ were varied to study their effects on both quantitative and qualitative hole drilling parameters. The unique techniques of assisting the abrasive feed process, ramping the waterjet pressure, during drilling, and varying the jet dwell time after piercing were effectively implemented to control hole quality and size. The results of the experiments indicate the accuracy and repeatability of the AWJ technique in meeting the air flow and hole size requirements. Production parts were drilled for prototype engine testing.

Hashish, M.; Whalen, J.

1991-09-01

361

A physically-based abrasive wear model for composite materials  

SciTech Connect

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.

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

2001-05-01

362

Developing a Process Model for Abrasive Flow Machining  

Microsoft Academic Search

\\u000a Abrasive flow machining (AFM) is a unique machining method used to achieve high surface quality on inner, difficult-to-access\\u000a contours and on outside edges. Using AFM, it is possible to deburr complex shaped intersecting holes and to realize pre-defined\\u000a edge rounding on any brittle or hard material. Moreover it is easy to integrate into an automated manufacturing environment.\\u000a Reproducibility of results

E. Uhlmann; V. Mihotovic; H. Szulczynski; M. Kretzschmar

363

Visualization of the abrasive-waterjet cutting process  

Microsoft Academic Search

Cutting with abrasive waterjets was visualized in three types of materials: Lexan, Lucite and glass. Movie cameras were used\\u000a at speeds of 64 and 1000 frames\\/s to record sequences of the jet penetration in these materials. It was found that the cutting\\u000a process consists of two basic modes of erosion. The first, known as the cutting-wear mode, occurs at relatively

Mohamed Hashish

1988-01-01

364

Optimum Path Planning of Robotic Free Abrasive Polishing Process  

Microsoft Academic Search

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

Guangchao Han; Ming Sun

2008-01-01

365

Mechanism of abrasive polishing of refractory transition metals  

Microsoft Academic Search

1.A study was made of the relationship between the ductility of titanium, niobium, and tungsten carbides and the amount of material removed from Groups IV–VI refractory transition metals during abrasive polishing and also of the relationship between the surface finish acquired by these metals during polishing and their mechanical properties.2.It was established that, for all the metals investigated, the greater

G. V. Samsonov; L. A. Gaevskaya; A. A. Adamovskii

1976-01-01

366

ABRASIVE MACHINING OF GLASS-CERAMICS WITH A DENTAL HANDPIECE  

Microsoft Academic Search

Dental restorations are commonly prepared from machinable glass-ceramics using modern dental CAD\\/CAM systems. Unfortunately, little is understood about the influence of machining parameters on material removal rates and any damage which could be introduced into the restoration during the abrasive machining processes employed with these systems. These effects are investigated for three experimental machinable glass-ceramics with varying microstructure and one

X. Dong; L. Yin; S. Jahanmir; L. K. Ives; E. D. Rekow

2000-01-01

367

Optimizing fracture toughness and abrasion resistance in white cast irons  

Microsoft Academic Search

A series of twelve Cr-Mo white irons varying in carbide volume from 7 to 45 pct were tested for dynamic fracture toughness\\u000a and wet sand abrasion resistance. Carbon content was varied from 1.4 to 3.9 pct. Two matrix microstructures were employed,\\u000a and the compositions (copper and chromium content) were varied to assure constant matrix compositions. Chromium was varied\\u000a from 11.6

Karl-Heinz Zum Gahr; Douglas V. Doane

1980-01-01

368

Subsurface damage in the abrasive machining of titanium aluminide (gamma)  

Microsoft Academic Search

This research concerns experimental and modeling results for the grinding of titanium aluminides. These intermetallic compounds have unique characteristics such as high strength-to-weight ratio and high corrosion resistance. The research has involved grinding at various conditions with an abrasive diamond wheel, quantifying the subsurface damage by laser profiler, characterizing the type\\/pattern of damage by microscopy, and measuring forces and power

Luis Manuel Nelson Pino

1997-01-01

369

Optimization of abrasive water jet cutting of ductile materials  

Microsoft Academic Search

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:

Asif Iqbal; Naeem U. Dar; Ghulam Hussain

2011-01-01

370

Blasting injuries in surface mining with emphasis on flyrock and blast area security  

Microsoft Academic Search

Problem: Blasting is a hazardous component of surface mining. Serious injuries and fatalities result from improper judgment or practice during rock blasting. This paper describes several fatal injury case studies, analyzes causative factors, and emphasizes preventive measures. Method: This study examines publications by MSHA, USGS, and other authors. The primary source of information was MSHA's injury-related publications. Results: During the

T. S. Bajpayee; T. R. Rehak; G. L. Mowrey; D. K. Ingram

2004-01-01

371

Friction and Wear with a Single-Crystal Abrasive Grit of Silicon Carbide in Contact with Iron Base Binary Alloys in Oil: Effects of Alloying Element and Its Content.  

National Technical Information Service (NTIS)

Sliding friction experiments were conducted with various iron-base binary alloys (alloying elements were Ti, Cr, Mn, Ni, Rh, and W) in contact with a rider of 0.025-millimeter-radius, single-crystal silicon carbide in mineral oil. Results indicate that at...

K. Miyoshi D. H. Buckley

1979-01-01

372

[Abrasion reducing polyethylene ceramic-metal compound hip prosthesis head].  

PubMed

There are two specific problems in using metallic or ceramic heads for hip prostheses: (1) the amount of polyethylene abrasions in the cup caused by the heads (especially a metal head). (2) the polyethylene abrasions caused by Al2O3 ceramic heads is far less than metal heads, but its ability to adapt geometrically is limited due to its being less strong. The abrasions appear because of geometric differences in the prosthetic joint, local problems in the surface architecture and physical/chemical interactions between the different materials. In this study we compare the new "Titan-Niob Ceramic Multilayer Sandwich Head" (built three layers of microsegregation phases and three in-between layers of ultrathin metal, 8-10 microns thick, and a surface with integrated grease holes) with the common CoCrMo heads and Al2O3 ceramic heads. Testing 2,000,000 cycles in a bodylike liquid under permanent loads of 90 kPa, periodically increasing up to 250 kPa, simulating normal stress situations (i.e., walking), the "Titan-Niob Ceramic Multilayer Sandwich Head" showed major advantages over the metal heads and also over the ceramic heads even though the ceramic head has been accepted so far to have the best friction coefficient. Furthermore, there has been no problem in surface fracture with the "Titan-Niob Ceramic Multilayer Sandwich Head". PMID:7502087

Hennig, F F; Repenning, D

1995-10-01

373

Dressing methods for grinding wheels made of superhard abrasive materials  

NASA Astrophysics Data System (ADS)

As a result of the increase in the use of difficult-to-machine materials more and more machining tasks are falling within the sphere of grinding. Since the requirements that must be met by the working accuracy under conditions of high productivity of the working cycle are becoming ever more stringent, high-capacity grinding tools are essential. The development of new, superhard abrasives has provided the necessary conditions for achieving technological and economic advantages in the machining of high-alloy materials. In this context cubic crystalline boron nitride (CBN) is used as an abrasive in a number of new fields. After diamond, CBN is the hardest abrasive. While the machining of hard metals is still the field in which diamond grinding wheels are used, the use of CBN grinding wheels in the machining of high alloy, heated treated high-speed steel offers technological and economic advantages. The principal reasons for this are to be found in the fact that CBN does not have a chemical affinity to the alloying elements of the steel, but has a greater thermal stability than diamond.

Spur, G.

374

Development of underwater cutting system by abrasive water-jet  

NASA Astrophysics Data System (ADS)

The technology to cut objects in the ocean's depths with abrasive water jets was examined for possible application in view of the greater water depths and sophistication involved in work on the ocean floor today. A test model was developed to study this technology's safety and practicability. The test model was designed for use at great water depths and has functions and a configuration that are unlike equipment used on land. A continuous, stable supply of abrasive is a distinctive design feature. In land applications, there had been problems with plugged tubes and an uneven supply. For this reason, the abrasive was converted to slurry form, and a continuous pressurized tube pump system was adopted for supply to the nozzle head. Also, a hydraulic motor that does not employ oil or electric power was used to provide an underwater drive that is environment-friendly. The report outlines the technology's general design concept including its distinctive functions and its configuration for use at great depths, and the report provides great detail on the equipment.

Demura, Kenji; Yamaguchi, Hitoshi

1993-09-01

375

Surface characterization of current composites after toothbrush abrasion.  

PubMed

The present study was designed to evaluate the surface roughness and the gloss of current composites before and after toothbrush abrasion. We assessed forty dimensionally standardized composite specimens (n=8/group) from five composites: two nanohybrids (i. e., IPS Empress Direct Enamel and IPS Empress Direct Dentin), two microhybrids (i. e., Clearfil AP-X and Filtek Z250) and one organically modified ceramics (Admira). All of the specimens were polished with 4000-grid silicon carbide papers. Surface roughness was measured with a profilometer and gloss was measured with a glossmeter before and after powered toothbrush abrasion with a 1:1 slurry (dentifrice/tap water) at 12,000 strokes in a toothbrush simulator. There was a significant increase in the surface roughness and a reduction in gloss after toothbrush abrasion in all of the composites except Clearfil AP-X (p<0.05). Simple regression analysis showed that there was not an association between the surface roughness and the gloss (R(2)=0.191, p<0.001). PMID:23370873

Takahashi, Rena; Jin, Jian; Nikaido, Toru; Tagami, Junji; Hickel, Reinhard; Kunzelmann, Karl-Heinz

2013-01-01

376

Microstructural effects in abrasive wear: Final report for period September 15, 1981--March 14, 1986  

SciTech Connect

This report summarizes research performed on abrasion of metallic alloys. The work was designed to improve our understanding of the factors affecting abrasion rates in two-phase alloys containing large, hard second-phase particles (SPPs) such as carbides, since this class of alloys generally has very high abrasion resistance owing to the presence of such carbides. The project was divided into sections dealing with material removal in the carbide and matrix phases. The materials studied included Stellite and high Cr-Mo white cast irons and a set of specially prepared model alloys containing one of six types of artificial SPPs dispersed in a sintered matrix of pure Cu. Scratch tests were employed to simulate abrasion mechanisms, and specially designed scratch test systems were fabricated to permit scratch testing in-situ in the scanning electron microscope (SEM) and to permit scratches to be made at fixed depths of cut rather than fixed loads. Three types of abrasion tests were employed; a dry-sand rubber wheel abrasion test; a low-speed ''gouging'' abrasion test employing a special low-speed Al/sub 2/O/sub 3/ grinding wheel; and a pin-on-disc abrasion test using abrasive paper. Abrasive type and size was varied in the rubber wheel and the pin-on-disc tests. 27 refs., 10 figs., 5 tabs.

Kosel, T.H.

1988-03-08

377

Blast traumatic brain injury in the rat using a blast overpressure model.  

PubMed

Traumatic brain injury (TBI) is a serious health concern for civilians and military populations, and blast-induced TBI (bTBI) has become an increasing problem for military personnel over the past 10 years. To understand the biological and psychological effects of blast-induced injuries and to examine potential interventions that may help to prevent, attenuate, and treat effects of bTBI, it is valuable to conduct controlled animal experiments. This unit discusses available paradigms to model traumatic brain injury in animals, with an emphasis on the relevance of these various models to study blast-induced traumatic brain injury (bTBI). This paper describes the detailed methods of a blast overpressure (BOP) paradigm that has been used to conduct experiments with rats to model blast exposure. This particular paradigm models the pressure wave created by explosions, including improvised explosive devices (IEDs). PMID:23315947

Yarnell, Angela M; Shaughness, Michael C; Barry, Erin S; Ahlers, Stephen T; McCarron, Richard M; Grunberg, Neil E

2013-01-01

378

Blast-wave characteristics near Site 300  

SciTech Connect

The blast-wave overpressures propagating in the atmosphere near the Lawrence Livermore National Laboratory (LLNL) Site 300 have been measured at selected locations to determine whether the Site 300 blast operations will be hindered by the proposed construction of a residential development adjacent to its border.We tested high-explosives (HE) weights ranging from 14 to 545 lb under various weather conditions. Although more tests should be conducted before a definitive statement can be made on the blast propagation near Site 300, we offer the following preliminary interpretation of the results obtained to date. The readings at the closest locations show that the blast-wave overpressures exceed the 126-decibel (dB) level established by LLNL at about 250 lb of HE detonation. The weather conditions do not materially affect the pressure levels at these locations. Insufficient test data exist along the Corral Hollow Road perimeter, making it difficult to reasonably predict HE blast effects along the southern border. Therefore, we recommend that additional measurements be made along this and other boundaries in future tests, to provide more comprehensive data to help determine the blast-wave propagation characteristics in the proposed development areas. Blast-wave focusing may occur in the proposed residential development area under certain weather conditions. We recommend that this possibility should be addressed for its potentially adverse impact on the proposed residential area. Because the testing ground controlled by Physics International, Inc. (PI) is adjacent to Site 300, it is important to be aware of PI`s detonation activities. Peak overpressure measurements near PI`s Corral Hollow Road entrance reveal that PI shots over 25 lb HE have exceeded 126 dB, the limit established by LLNL for safe operations.

Kang, Sang-Wook; Kleiber, J.C. Jr.

1993-08-01

379

Alkahest NuclearBLAST : a user-friendly BLAST management and analysis system  

PubMed Central

Background - Sequencing of EST and BAC end datasets is no longer limited to large research groups. Drops in per-base pricing have made high throughput sequencing accessible to individual investigators. However, there are few options available which provide a free and user-friendly solution to the BLAST result storage and data mining needs of biologists. Results - Here we describe NuclearBLAST, a batch BLAST analysis, storage and management system designed for the biologist. It is a wrapper for NCBI BLAST which provides a user-friendly web interface which includes a request wizard and the ability to view and mine the results. All BLAST results are stored in a MySQL database which allows for more advanced data-mining through supplied command-line utilities or direct database access. NuclearBLAST can be installed on a single machine or clustered amongst a number of machines to improve analysis throughput. NuclearBLAST provides a platform which eases data-mining of multiple BLAST results. With the supplied scripts, the program can export data into a spreadsheet-friendly format, automatically assign Gene Ontology terms to sequences and provide bi-directional best hits between two datasets. Users with SQL experience can use the database to ask even more complex questions and extract any subset of data they require. Conclusion - This tool provides a user-friendly interface for requesting, viewing and mining of BLAST results which makes the management and data-mining of large sets of BLAST analyses tractable to biologists.

Diener, Stephen E; Houfek, Thomas D; Kalat, Sam E; Windham, DE; Burke, Mark; Opperman, Charles; Dean, Ralph A

2005-01-01

380

Blasting to the Substrate of Various Temperatures  

NASA Astrophysics Data System (ADS)

Blasting is a substrate processing technique during which spherical or granular materials made of metal or ceramics are jetted against the substrate surface using compressed air. The high speed colliding of blasting materials against the surface produces a peening effect. The purpose of blasting is to create a clean substrate surface. However, there are almost no investigations that consider the influence of the substrate temperature. The object of this investigation is to clarify the influence of substrate temperature on blasting. Results of this investigation are summarized as follows: in spite of the substrate material, the removal rate was the smallest at 260~270 K. Influence of substrate temperature on the removal rate of an Al substrate is larger than that of other substrates. Influence of substrate temperature on arc height is large when higher than the room temperature. Influence of substrate temperature on arc height of an Al substrate is larger than that of other substrates. As hardness HV value increases, arc height becomes large. Even if the substrate temperature changes, an Am substrate can be used as a standard substrate for the blasting process.

Kubohori, Toshifumi; Tojo, Yuichi; Inui, Yasuyuki

2010-10-01

381

Densification of pond ash by blasting  

SciTech Connect

Fly ash from thermal power plants is disposed, in huge quantities in ash ponds, which occupy large land areas otherwise useful for agriculture, housing, or other development. For effective rehabilitation of ash ponds, densification of the slurry deposit is essential to increase the bearing capacity and to improve its resistance to liquefaction. Extensive field trials were carried out to evaluate the effectiveness of deep blasting for densification of deposited fly ash. Ninety explosions comprising 15 single blasts, with varying depths and quantities of charges, and 3 group blasts, each having 25 charges placed at various spacings, were carried out. The compaction achieved in terms of an increase in relative density was evaluated from surface settlement measurements. Extensive field monitoring was undertaken through pore-water pressure measurements, vibration measurements, penetration tests, and block vibration tests. For the average charge of 2--4 g of explosive per cubic meter of untreated deposit, the average relative density was found to improve from 50% to 56--58%. Analysis of the test results indicates that deep blasting may be an effective technique for modest compaction of loose fly ash deposits. The field testing program presented in this paper provides valuable information that can be used for planning blast densification of fly ash deposits.

Gandhi, S.R.; Dey, A.K.; Selvam, S. [Indian Inst. of Tech., Madras (India)

1999-10-01

382

Bayesian detection of acoustic muzzle blasts  

NASA Astrophysics Data System (ADS)

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.

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

2009-05-01

383

Characterization of blasted austenitic stainless steel and its corrosion resistance  

NASA Astrophysics Data System (ADS)

It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180 paper. A martensite phase is formed in the surface layer of both blasted and scraped specimens. Compressive residual stress is generated in the blasted specimen and the maximum residual stress is formed at 50 100 µm from the surface. The corrosion potentials of the blasted specimen and subsequently solution treated specimen are lower than that of the non-blasted specimen. The passivation current densities of the blasted specimens are higher those of the non-blasted specimen. The blasted specimen and the subsequently solution treated specimen exhibit rust in 5% sodium chloride (NaCl) solution, while the non-blasted specimen and ground specimen do not rust in the solution. It is concluded that the deterioration of corrosion resistance of austenitic stainless steel through blasting is caused by the roughed morphology of the surface.

Otsubo, F.; Kishitake, K.; Akiyama, T.; Terasaki, T.

2003-12-01

384

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2013 CFR

...Blasting signs, warnings, and access control. 817.66 Section 817.66...Blasting signs, warnings, and access control. (a) Blasting signs. Blasting...in § 817.64(a). (c) Access control. Access within the...

2013-07-01

385

Thickness of softened human enamel removed by toothbrush abrasion: an in vitro study.  

PubMed

The aim of the study was to assess the thickness of softened enamel removed by toothbrushing. Human enamel specimens were indented with a Knoop diamond. Softening was performed with citric acid or orange juice. The specimens were brushed in a brushing machine with a manual soft toothbrush in toothpaste slurry or in artificial saliva. Enamel loss was calculated from the change in indentation depth of the same indent before and after abrasion. Mean surface losses (95% confidence interval) were recorded in treatment groups (in nanometers): (1) citric acid, abrasion with slurry = 339 (280-398); (2) citric acid, abrasion with artificial saliva = 16 (5-27); (3) orange juice, abrasion with slurry = 268 (233-303); (4) orange juice, abrasion with artificial saliva = 14 (5-23); (5) no softening, abrasion with slurry = 28 (10-46). The calculated thickness of the softened enamel varied between 254 and 323 nm, depending on the acid used. PMID:19499254

Voronets, J; Lussi, A

2009-06-05

386

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

NASA Astrophysics Data System (ADS)

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.

Manivannan, R.; Ramanathan, S.

2009-01-01

387

Wear mechanisms in ball-cratering tests with large abrasive particles  

Microsoft Academic Search

Three-body abrasive wear resistance of mild steel and 27%Cr white cast iron was investigated using a ball-cratering test. Glass beads, silica sand, quartz and alumina abrasive particles with sizes larger than 200?m were used to make slurries. It was found that the wear rates of mild steel increased with sliding time for all abrasive particles tested, while the wear rates

G. B. Stachowiak; G. W. Stachowiak

2004-01-01

388

Basic observations in the flat lapping of aluminum and steels using standard abrasives  

Microsoft Academic Search

This research studies the characteristics of aluminum 2024, 304 stainless steel, and 1018 steel during lapping with three\\u000a different types of abrasives, namely, garnet, silicon carbide, and white aluminum oxide, through detailed experimental analysis.\\u000a Specifically, the effects of different abrasives on material removal rate and surface finish were evaluated. It was found\\u000a that silicon carbide and white aluminum oxide abrasives

Casmir Agbaraji; Shivakumar Raman

2009-01-01

389

Boronizing of cast martensitic chromium nickel stainless steel and its abrasion and cavitation-erosion behaviour  

Microsoft Academic Search

Boronizing of steels has been very effectively used in overcoming adhesive, sliding and abrasive wear. However, little information is available on boronized cast chromium–nickel steel (13Cr–4Ni) with regard to cavitation-erosion and abrasion resistance as well as their effect on mechanical properties. In this paper, the cavitation-erosion characteristics along with abrasive wear of boronized 13Cr–4Ni steel are studied in detail. Cavitation-erosion

B. S Mann

1997-01-01

390

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

Microsoft Academic Search

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

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

2010-01-01

391

[Forensic medical examination of abrasions in the study of mummified tissues in experiment].  

PubMed

Morphological and biophysical characteristics of abrasions and intact skin were studied during the process of their mummification at temperatures from 40 to 70 degrees C. The time after which the injuries become undetectable because color of the skin and injuries coincides, was determined. Changes in configuration and area of abrasions while drying are described. The rate of mummification and duration of the latter were established by dielectric indices of abrasions and skin at 10 cm wave length. PMID:16279493

Ten'kov, A A

392

High temperature abrasive wear behavior of an as-cast ductile iron  

Microsoft Academic Search

In this study, high temperature abrasive wear behavior of a GGG 40 quality as-cast ductile iron was examined. Wear tests were performed under a compression stress of 5.7N\\/mm2, by rubbing the samples (pins) on Al2O3 abrasive grains at various temperatures in between 25 and 600°C. The examined ductile iron exhibited the highest resistance to abrasion at temperature range between 50

Ozgur Celik; Hayrettin Ahlatci; E. Sabri Kayali; Huseyin Cimenoglu

2005-01-01

393

Micro machining of an STS 304 bar by magnetic abrasive finishing  

Microsoft Academic Search

A magnetic abrasive finishing process is a method of non-traditional precision machining in which the finishing process is\\u000a completed using magnetic force and magnetic abrasives. In this research, a STS 304 cylindrical workpiece was finished using\\u000a a magnetic abrasive finishing process at 30,000 rpm, and the roughness, roundness, and changes in the micro-diameter were\\u000a investigated. The study showed that it

Ik-Tae Im; Sang Don Mun; Seong Mo Oh

2009-01-01

394

Study of magnetic abrasive finishing in free-form surface operations using the Taguchi method  

Microsoft Academic Search

This study employed magnetic abrasive finishing (MAF) to conduct free-form surface abrasion of stainless SUS304 material operations.\\u000a The operations were demonstrated using a permanent magnetic finishing mechanism installed at the CNC machining center. The\\u000a operations were performed using the Taguchi experimental design, considering the effects of magnetic field, spindle revolution,\\u000a feed rate, working gap, abrasive, and lubricant. Furthermore, the experimental

Ching-Tien Lin; Lieh-Dai Yang; Han-Ming Chow

2007-01-01

395

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

Microsoft Academic Search

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

Li Changhe; Mao Weiping; Du Chao; Liu Zhanrui

2010-01-01

396

Numerical simulation of single particle acceleration process by SPH coupled FEM for abrasive waterjet cutting  

Microsoft Academic Search

The existing numerical simulations of hydrodynamic characteristics of abrasive waterjet in a cutting head were mainly based\\u000a on Eulerian grid or arbitrary Lagrange–Eulerian grid method to establish computational fluid dynamics models. However, using\\u000a these two methods, the abrasive and water were premixed and given an identical initial velocity, which were different from\\u000a the mixing and acceleration processes of abrasive in

Yu Feng; Wang Jianming; Liu Feihong

397

Single Pass Streaming BLAST on FPGAs*†  

PubMed Central

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.

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

2008-01-01

398

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

399

EXTERIOR VIEW, BLAST FURNACE NO. 3 (JANE FURNACE) CENTER, NO. ...  

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

EXTERIOR VIEW, BLAST FURNACE NO. 3 (JANE FURNACE) CENTER, NO. 3 CAST HOUSE TO THE LEFT, WEST ORE BRIDGE TO THE RIGHT. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

400

VIEW LOOKING NORTHWEST WITH OPENHEARTH TO LEFT WITH BLAST FURNACE ...  

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

VIEW LOOKING NORTHWEST WITH OPEN-HEARTH TO LEFT WITH BLAST FURNACE NO. 2 AND CAST HOUSE TO THE RIGHT. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

401

INTERIOR VIEW LOOKING EAST, BLAST FURNACE NO. 1 CLOSEUP, IRON ...  

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

INTERIOR VIEW LOOKING EAST, BLAST FURNACE NO. 1 CLOSE-UP, IRON NOTCH IN CENTER. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

402

30 CFR 57.6306 - Loading, blasting, and security.  

Code of Federal Regulations, 2010 CFR

...device, all persons shall leave the blast area except persons in a blasting shelter or other location that protects them from concussion (shock wave), flying material, and gases. (f) Before firing a blastâ (1) Ample warning shall be given to...

2009-07-01

403

30 CFR 56.6306 - Loading, blasting, and security.  

Code of Federal Regulations, 2010 CFR

...device, all persons shall leave the blast area except persons in a blasting shelter or other location that protects them from concussion (shock wave), flying material, and gases. (f) Before firing a blastâ (1) Ample warning shall be given to...

2009-07-01

404

Underwater Blast Injury - a Review of the Literature.  

National Technical Information Service (NTIS)

Underwater blast injury is reviewed for the period 1916 to the present date (1970). The physics of the blast, the mechanism of injury, the pathology, and clinical considerations are discussed. A discussion and criticism is presented of the various formula...

N. M. Wolf

1970-01-01

405

Enhancements and Analysis of CTH Software for Underbody Blast.  

National Technical Information Service (NTIS)

Accurate tools and procedures for simulating the blast effects of shallow buried explosive devices are critical to the Department of Defense's efforts to design blast-resistant vehicles that can increase crew survivability and counter the threat from impr...

C. Moore R. Thyagarajan R. Weed

2013-01-01

406

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

407

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

408

30 CFR 57.6306 - Loading, blasting, and security.  

Code of Federal Regulations, 2013 CFR

...device, all persons shall leave the blast area except persons in a blasting shelter or other location that protects them from concussion (shock wave), flying material, and gases. (f) Before firing a blastâ (1) Ample warning shall be given to...

2013-07-01

409

30 CFR 56.6306 - Loading, blasting, and security.  

Code of Federal Regulations, 2013 CFR

...device, all persons shall leave the blast area except persons in a blasting shelter or other location that protects them from concussion (shock wave), flying material, and gases. (f) Before firing a blastâ (1) Ample warning shall be given to...

2013-07-01

410

30 CFR 56.6605 - Isolation of blasting circuits.  

Code of Federal Regulations, 2013 CFR

...METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits...and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from...

2013-07-01

411

Characterization of abrasion surfaces in rock shore environments of NW Spain  

NASA Astrophysics Data System (ADS)

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 Sartaña 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.

Feal-Pérez, Alejandra; Blanco-Chao, Ramón

2013-04-01

412

Blast-furnace performance with coal-dust injection  

Microsoft Academic Search

For the blast-furnace shop at OAO Alchevskii Met- allurgicheskii Kombinat (AMK), the injection of coal- dust fuel is promising. Preliminary steps toward its introduction are underway, including analytical research. In this context, we calculate blast-furnace per- formance when using coal-dust fuel in the present work. As in any combined blast, the consumption of coal- dust fuel in unit blast and

G. G. Vasyura

2007-01-01

413

A rotary-airlock valve resists abrasive mixtures  

SciTech Connect

Hill and Griffith (H and G, Cincinnati, Ohio) is a leading supplier of custom-blended additives to founderies. Thousands of tons of clay and carbon blends such as bentonite, gilsonite and pulverized coal, pass through the company's rotary-airlock feeding system each month. H and G's original rotary valves had cylinders lined with chrome, and closed-end rotors with tips made from nickel-chromium alloys. These valves remained in service for a maximum of only three months each. During that time, the abrasive mixtures passing through the valves virtually eroded them, increasing tolerances and causing significant air leakage. The leaks caused the pneumatic line to plug up, reducing the velocity of the line below the minimum level needed to carry any material. To overcome the leakage, a second blower was added to the system. This unit supplied an additional 40 brake hp to the pneumatic-conveying line. With constant maintenance of the valve and the continuous operation of both blowers, H and G was able to extend the valve's life by nine months. After 20 years of trying valves with various configuration, H and G installed a Smoot Type 6 rotary-airlock valve in September of 1985. The new valve's internals were made from abrasion-resistant grades of NiHard and Stellite. This combination of alloys prolonged the active life of the valve by improving its abrasion resistance. During its first year, the Smoot valve did not break down, leak air or require use of the secondary blower. After its first year of service no wear was found on the valve's internal surfaces. Another mechanical analysis was performed in 1991, after five additional years of valve operation. The valve, which had now handled more than 250,000 tons of product, showed minimal wear. H and G's capital costs had been reduced from 25[cents]/ton to 3[cents]/ton by the new valve.

Not Available

1993-03-01

414

Thermal effects in blasting and erosion of polymeric materials  

Microsoft Academic Search

The application of solid particle blasting has been investigated as a means for the removal of coatings from polymeric substrates for reuse and recycling. Experimentally, it has been observed that during particle blasting, substantial temperature rises are observed in the polymer substrates, even when the blast media is solid carbon dioxide at less than ?78.5°C. Such temperature rises are not

P. H. Shipway; D. P. Weston

2009-01-01

415

Layered sacrificial claddings under blast loading Part I — analytical studies  

Microsoft Academic Search

In this paper, we present the behaviour of layered sacrificial claddings subjected to blast loading.The cladding layers are constructed out of thin mild steel sheets. The blast load was modelled as an equivalent triangular blast pulse. Both experimental and numerical analyses have been carried out. The analytical work is presented in this paper. Finite element analysis with step by step

S. Guruprasad; Abhijit Mukherjee

2000-01-01

416

Nineteen-Foot Diameter Explosively Driven Blast Simulator  

Microsoft Academic Search

This report describes the 19-foot diameter blast tunnel at Sandia National Laboratories. The blast tunnel configuration consists of a 6 foot diameter by 200 foot long shock tube, a 6 foot diameter to 19 foot diameter conical expansion section that is 40 feet long, and a 19 foot diameter test section that is 65 feet long. Therefore, the total blast

MANUEL G

2001-01-01

417

Spectrum of abdominal organ injury in a primary blast type  

Microsoft Academic Search

INTRODUCTION: Abdominal organ injury in a primary blast type is always challenging for diagnosis. Air containing abdominal viscera is most vulnerable to effects of primary blast injury. In any patient exposed to a primary blast wave who presents with an acute abdomen, an abdominal organ injury is to be kept in a clinical suspicion. AIM: Study various abdominal organ injuries

Imtiaz Wani; Fazal Q Parray; Tariq Sheikh; Rauf A Wani; Abid Amin; Imran Gul; Mir Nazir

2009-01-01

418

Electrohydraulic rock blasting for mining in urban areas  

Microsoft Academic Search

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

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

2001-01-01

419

Reevaluation of refractory anemia with excess blasts in transformation  

Microsoft Academic Search

The category ‘refractory anemia with excess blasts in transformation (RAEBt)’ consists of two sub-sets; one group is categorized based on the percentage of blasts in the marrow (?20%) and other is based on the percentage of blasts in the peripheral blood (?5%). We separated RAEBt patients based on these two criteria and compared hematologic and clinical relevance to assess the

Kazuma Ohyashiki; Jiroh Nishimaki; Nahoko Shoji; Keisuke Miyazawa; Yukihiko Kimura; Junko H Ohyashiki

2001-01-01

420

The abrasive wear behaviour of continuous fibre polymer composites  

Microsoft Academic Search

The dry abrasive-dominant wear behaviour of several composite materials consisting of uni-directional continuous fibres and polymer matrices was investigated. Seven materials were examined: neat epoxy (3501-6), carbon fibre epoxy (AS4\\/3501-6), glass fibre\\/epoxy (E-glass\\/ 3501-6), aramid fibre\\/epoxy (K49\\/3501-6), neat polyetheretherketone (PEEK), carbon fibre\\/PEEK (APC2) and aramid fibre\\/PEEK (K49\\/PEEK). The wear behaviour of the materials was characterized by experimentally determining the friction

M. Cirino; R. B. Pipes; K. Friedrich

1987-01-01

421

Solution of the Roth-Marques-Durian rotational abrasion model  

NASA Astrophysics Data System (ADS)

We solve the rotational abrasion model of Roth, Marques, and Durian [Phys. Rev. EPRLTAO1539-375510.1103/PhysRevE.83.031303 83, 031303 (2011)], a one-dimensional quasilinear partial differential equation resembling the inviscid Burgers equation with the unusual feature of a step function factor as a coefficient. The complexity of the solution is primarily in keeping track of the cases in the piecewise function that results from certain amputation and interpolation processes, so we also extract from it a model of an evolving planar tree graph that tracks the evolution of the coarse features of the contour.

Chen, Bryan Gin-Ge

2011-03-01

422

Some speculations on the mechanisms of abrasive grinding and polishing  

SciTech Connect

The mechanisms of grinding, a predominantly fracture mechanism in brittle material, and polishing, a predominantly plastic shearing mechanism, appear quite different. However, in a number of cases it can be shown that the difference between the two mechanisms can be triggered by differences in depth of cut and abrasive size. This paper will present results from recent polishing research that tend to support a physico-chemical interaction model involving aqueous diffusion, internal hydrolysis, and ion exchange mechanisms that may explain the plastic to brittle transition in silicate materials. The model would seem to have clear implications for both low scatter polishing and fine machining of silicate materials.

Brown, N.J.

1987-05-11

423

[Filling composites. Experimental study of surface finishing by abrasion].  

PubMed

Dealing with composite resins, our work is an account of personal researches on the methods and means of polishing. We have tested four rotary abrasive instruments on two composite resins: diamond burs, white Arkansas stones, silicon-carbide polishers, flexible polyurethane-based finishing and polishing disks. The results of the obtained measures of the surface roughness have enabled us to select a limited specific instrumentation which is included in a second experimentation leading to the conception of simple finishing procedures of the composite resins. PMID:2077864

Briand, D E

1990-12-01

424

Assessment of Atmospheric Emissions from Quenching of Blast Furnace Slag with Blast Furnace Blowdown Water.  

National Technical Information Service (NTIS)

The report gives results of 15 emission measurements made on a laboratory scale facility simulating typical plant slag quenching practice. The measurements were made to determine if a potential alternative to treatment prior to discharge of blast furnace ...

G. Annamraju W. Kemner P. J. Schworer

1984-01-01

425

A direction-sensitive underwater blast detector and its application for managing blast fishing.  

PubMed

Little is known about the spatial and temporal distribution of blast fishing which hampers enforcement against this activity. We have demonstrated that a triangular array of hydrophones 1 m apart is capable of detecting blast events whilst effectively rejecting other sources of underwater noise such as snapping shrimp and nearby boat propellers. A total of 13 blasts were recorded in Sepangor bay, North of Kota Kinabalu, Sabah, Malaysia from 7th to 15th July 2002 at distances estimated to be up to 20 km, with a directional uncertainty of 0.2 degrees . With such precision, a network of similar hydrophone arrays has potential to locate individual blast events by triangulation to within 30 m at a range of 10 km. PMID:15556182

Woodman, George H; Wilson, Simon C; Li, Vincent Y F; Renneberg, Reinhard

2004-12-01

426

Swift GRBs and the blast wave model  

NASA Astrophysics Data System (ADS)

The complex structure of the light curves of Swift GRBs has made their interpretation and that of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to constrain the blast wave parameters: electron energy distribution, p, density profile of the circumburst medium, k, and the continued energy injection index, q. We do so by comparing the observed multi-wavelength light curves and X-ray spectra of a Swift sample to the predictions of the blast wave model. We can successfully interpret all of the bursts in our sample of 10, except two, within the framework of the blast wave model, and we can estimate with confidence the electron energy distribution index for 6 of the sample. Furthermore we identify jet breaks in half of the bursts. A statistical analysis of the distribution of p reveals that, even in the most conservative case of least scatter, the values are not consistent with a single, universal value. The values of k suggest that the circumburst density profiles are not drawn from only one of the constant density or wind-like media populations.

Curran, P. A.; van der Horst, A. J.; Starling, R. L. C.; Wijers, R. A. M. J.

2009-05-01

427

Use of Waste Oil in Blast Furnaces.  

National Technical Information Service (NTIS)

The project dealt with investigating the conditions under which waste oil could be used instead of heavy fuel oil to fire blast furnaces so as to permit cost savings. When using waste oil, the pumps in the feed line that were used to build up the supply p...

K. Goebel

1983-01-01

428

PMB (Plastic Media Blasting): An Implementation Report.  

National Technical Information Service (NTIS)

The report is aimed at determining how to cause a plastic media blasting facility in the Ardmore Industrial Airpark. It outlines a detailed asset plan that includes an architectural model for multi-use large aircraft maintenance hangars. The market analys...

1988-01-01

429

Plastic Media Blasting Data Gathering Study.  

National Technical Information Service (NTIS)

Plastic Media Blasting (PMB) is proving to be a cost effective method of paint removal with many benefits. Economic savings may reach 50 percent of chemical stripping costs, while hazardous waste volumes can be reduced by up to 90 percent. This task gathe...

1986-01-01

430

Thermal Treatment of Plastic Media Blasting Waste.  

National Technical Information Service (NTIS)

Plastic media blasting (PMB) is a process employed by the Air Force and others to strip protective coatings from aircraft and other equipment. The waste is made up of about 90% plastic medium and 10% paint residue, when garnet is not used. The plastic med...

U. Gat M. D. Kass D. B. Lloyd

1995-01-01

431

Plastic Media Blasting (PMB) waste treatment technology  

Microsoft Academic Search

Environmental and occupational hazard regulations have motivated consideration of several new developments in paint removal technology. Plastic Media Blasting (PMB)\\/paint wastes consist predominantly of degraded plastic media plus the stripped paint. They are, in general, placed in the category of being characteristically hazardous'' according to the definition in the RCRA Act because of the excess leachability of toxic metals. The

H. Jermyn; R. P. Wichner

1991-01-01

432

BLAST: Building energy simulation in Hong Kong  

Microsoft Academic Search

The characteristics of energy use in buildings under local weather conditions were studied and evaluated using the energy simulation program BLAST-3.0. The parameters used in the energy simulation for the study and evaluation include the architectural features, different internal building heat load settings and weather data. In this study, mathematical equations and the associated coefficients useful to the industry were

Sai-Keung Fong

1999-01-01

433

Design of blast simulators for nuclear testing  

Microsoft Academic Search

A quasi-dimensional computational technique is used to model the flow of a large, complicated shock tube. The shock tube, or Large Blast Simulator, is used to simulate conventional or nuclear explosions by shaping the pressure history. Results from computations show favorable agreement when compared with data taken in the facility at Gramat, France. Such future shock tubes will include a

A. Mark; K. O. Opalka; C. W. Jr. Kitchens

1981-01-01

434

BLAST resolves origins of Cosmic Infrared Background  

NASA Astrophysics Data System (ADS)

The cosmic infrared background (CIB), composed of starlight which is absorbed by dust and re-emitted at infrared wavelengths, has approximately the same intensity as the optical background. The CIB is most intense at around 200,m, where the atmosphere is very opaque, which makes observing it very difficult. The Balloon-borne Large-Aperture Submillimetre Telescope (BLAST) operates above 99.5% of the atmosphere and has made the first direct observations at 250, 350 and 500,m. In December 2006, BLAST completed an 11-day flight over Antarctica. 220 hours of data were collected, 90 of which were spent in the Great Observatories Origins Deep Survey (GOODS) South Field. We calculate the covariance of the BLAST data with catalogs of 24,m sources. With this method, we measure the CIB brightness levels at BLAST wavelengths. This analysis resolves the CIB into contributions from 24,m identified galaxies. At 500,m, we find that over half of the light comes from sources with redshifts greater than 1.2. Furthermore, this analysis allows us to determine the characteristics of the galaxies which produce the CIB.

Ngo, Henry

2009-05-01

435

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...

436

MODELING BLAST-RELATED BRAIN INJURY  

Microsoft Academic Search

Recent military conicts in Iraq and Afghanistan have highlighted the wartime eect of traumatic brain in- jury (TBI). While it is not clear why TBI has been so prominent in these particular conicts, one reason may be that improvements in body armor have led to in- creased survivability of blasts. Closed traumatic brain injury covers a spectrum of central nervous

M. Nyein; A. J erusalem; R. Radovitzky; D. Moore; L. Noels

437

People Interview: Solar physics blasts into space  

NASA Astrophysics Data System (ADS)

INTERVIEW Solar physics blasts into space Lucie Green's physics and astrophysics degree has taken her to the Crimea to study binary stars and to the Mullard Space Science Laboratory. David Smith talks to her about her career as a solar physicist and her involvement in outreach activities.

2010-09-01

438

Expanding Blast Furnace Slag Without Air Pollution  

Microsoft Academic Search

Expansion of blast furnace slag causes emissions of hydrogen sulfide, creating an air pollution problem common throughout the steel industry. This paper describes a new process, called pelletizing which eliminates the air pollution problem while at the same time producing a superior slag product.

Richard Jablin

1972-01-01

439

The Stability of Plane Blast Waves.  

National Technical Information Service (NTIS)

The stability of a plane blast wave to surface perturbations is examined. It is found possible by making a 'thin' sheet approximation to the geometry, to obtain a set of ordinary differential equations which describe the sheet motion. These equations are ...

R. Gerwin R. B. Hall

1968-01-01

440

Dangers of Toxic Fumes from Blasting  

Microsoft Academic Search

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

Richard J. Mainiero; Marcia L. Harris

441

Comment on "chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model".  

PubMed

In their recent paper, Goldstein et al. show murine brain tau neuropathology after explosive blast with head rotation but do not present additional evidence that would delineate whether this neuropathology was principally caused by blast exposure alone or by blast exposure plus head rotational injury. PMID:23100624

Tsao, Jack W

2012-10-24

442

The Foulness multiton air blast simulator. Part 3: Blast wave formation and methods used to drive the simulator  

Microsoft Academic Search

The mechanisms by which blast waves are generated by a helical charge of detonating fuse in a 4.9 m diameter nuclear air blast simulator were studied in order to achieve control over the waveform produced. The problem of producing low pressure blast waves with long duration was overcome by immersing the charge in an aqueous foam in the firing chamber.

P. M. Clare

1980-01-01

443

Effects of geometry on blast-induced loadings  

NASA Astrophysics Data System (ADS)

Simulations of blasts in an urban environment were performed using Loci/BLAST, a full-featured fluid dynamics simulation code, and analyzed. A two-structure urban environment blast case was used to perform a mesh refinement study. Results show that mesh spacing on and around the structure must be 12.5 cm or less to resolve fluid dynamic features sufficiently to yield accurate results. The effects of confinement were illustrated by analyzing a blast initiated from the same location with and without the presence of a neighboring structure. Analysis of extreme pressures and impulses on structures showed that confinement can increase blast loading by more than 200 percent.

Moore, Christopher Dyer

444

Attrition and abrasion models for oil shale process modeling  

SciTech Connect

As oil shale is processed, fine particles, much smaller than the original shale are created. This process is called attrition or more accurately abrasion. In this paper, models of abrasion are presented for oil shale being processed in several unit operations. Two of these unit operations, a fluidized bed and a lift pipe are used in the Lawrence Livermore National Laboratory Hot-Recycle-Solid (HRS) process being developed for the above ground processing of oil shale. In two reports, studies were conducted on the attrition of oil shale in unit operations which are used in the HRS process. Carley reported results for attrition in a lift pipe for oil shale which had been pre-processed either by retorting or by retorting then burning. The second paper, by Taylor and Beavers, reported results for a fluidized bed processing of oil shale. Taylor and Beavers studied raw, retorted, and shale which had been retorted and then burned. In this paper, empirical models are derived, from the experimental studies conducted on oil shale for the process occurring in the HRS process. The derived models are presented along with comparisons with experimental results.

Aldis, D.F.

1991-10-25

445

Material removal mechanisms in abrasive vibration polishing of complex molds  

NASA Astrophysics Data System (ADS)

Optical and medical industries are demanding a large variety of optical elements exhibiting complex geometries and multitude opto-functional areas in the range of a few millimeters [1]. Therefore, mold inserts made of steel or carbides must be finished by polishing for the replication of glass and plastic lenses [2]. For polishing theses complex components in the shape of localized cavities or grooves the application of rotating polishing pads is very limited. Established polishing processes are not applicable, so state of the art is a time consuming and therefore expensive polishing procedures by hand. An automated process with conventional polishing machines is impossible because of the complex mold insert geometry. The authors will present the development of a new abrasive polishing process for finishing these complex mold geometries to optical quality. The necessary relative velocity in the contact area between polishing pad and workpiece surface is exclusively realized by vibration motions which is an advantage over vibration assisted rotating polishing processes. The absence of rotation of the pad opens up the possibility to machine new types of surface geometries. The specific influence factors of vibration polishing were analyzed and will be presented. The determination of material removal behavior and polishing effect on planar steel samples has shown that the conventional abrasive polishing hypothesis of Preston is applicable to the novel vibration polishing process. No overlaid chemical material removal appears.

Brinksmeier, E.; Riemer, O.; Schulte, H.

2010-05-01

446

Air abrasion experiments in U-Pb dating of zircon  

USGS Publications Warehouse

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.

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

1986-01-01

447

Prediction Of Abrasive And Diffusive Tool Wear Mechanisms In Machining  

NASA Astrophysics Data System (ADS)

Tool wear prediction is regarded as very important task in order to maximize tool performance, minimize cutting costs and improve the quality of workpiece in cutting. In this research work, an experimental campaign was carried out at the varying of cutting conditions with the aim to measure both crater and flank tool wear, during machining of an AISI 1045 with an uncoated carbide tool P40. Parallel a FEM-based analysis was developed in order to study the tool wear mechanisms, taking also into account the influence of the cutting conditions and the temperature reached on the tool surfaces. The results show that, when the temperature of the tool rake surface is lower than the activation temperature of the diffusive phenomenon, the wear rate can be estimated applying an abrasive model. In contrast, in the tool area where the temperature is higher than the diffusive activation temperature, the wear rate can be evaluated applying a diffusive model. Finally, for a temperature ranges within the above cited values an adopted abrasive-diffusive wear model furnished the possibility to correctly evaluate the tool wear phenomena.

Rizzuti, S.; Umbrello, D.

2011-01-01

448

Abrasion Resistance of Safety Lenses. Effects of Abrasion on Toughened Safety Glass and Plastic Lenses with Respect to their Optical Properties.  

National Technical Information Service (NTIS)

The abrasion resistance is studied of safety spectacle and goggle lenses made from acetate, CR-39, (diallyl diglycol carbonate), polycarbonate, toughened glass, vinyl and vinyl treated with an anti-fog coating. In addition, the optical properties of prism...

D. M. Ascenzi

1976-01-01

449

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...

450

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

Microsoft Academic Search

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

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

2010-01-01

451

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

Microsoft Academic Search

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

Chuansi Gao; John Abeysekera; Mikko Hirvonen; Carita Aschan

2003-01-01

452

Influence of abrasion on the surface characteristics of thermally sprayed hydroxyapatite coatings  

Microsoft Academic Search

The surface condition of hydroxyapatite thermal sprayed coatings can be measured in terms of smooth melted and unmelted regions. Both these areas collectively contribute to abrasion resistance of a coated implant. The purpose of this work was to determine the influence of abrasion on the surface characteristics of coatings. Coatings with three degrees of roughness (Ra of 7, 10 and

K. A Gross; M Babovic

2002-01-01

453

Rock coatings and aeolian abrasion on Mars: Application to the Pathfinder landing site  

Microsoft Academic Search

Rock coatings can be used to constrain the rate of abrasion by wind on Mars. The susceptibility to abrasion for potential rock coatings on Mars (salt\\/salt-cemented coatings, rock varnish, and amorphous silica) were determined experimentally. Rock coatings generally abrade more easily than the host rock, although amorphous silica is an exception. If coatings exist on rocks at the Mars Pathfinder

Michael D. Kraft; Ronald Greeley

2000-01-01

454

Finite element analysis of single-particle impact in abrasive water jet machining  

Microsoft Academic Search

This contribution presents an explicit finite element analysis (FEA) of a single abrasive particle impact on stainless steel 1.4301 (AISI 304) in abrasive water jet (AWJ) machining. In the experimental verification, the shapes of craters on the workpiece material were observed and compared with FEA simulation results by means of crater sphericity. The influences of the impact angle and particle

M. Junkar; B. Jurisevic; M. Fajdiga; M. Grah

2006-01-01

455

Abrasion and chemical–mechanical polishing between steel and a sputtered boron carbide coating  

Microsoft Academic Search

When a steel ball undergoes dry sliding against a boron carbide-coated steel coupon, both the steel ball and the boron carbide are polished, even though the boron carbide is several times harder than the steel. We have measured the abrasion rate of the steel under loads ranging from 5 to 1100g. The average abrasion rate at and above 100g of

S. J. Harris; G. G. Krauss; S. J. Simko; R. J. Baird; S. A. Gebremariam; G. Doll

2002-01-01

456

Abrasion resistance of concrete as influenced by inclusion of fly ash  

Microsoft Academic Search

This research was conducted to evaluate abrasion resistance of high-volume fly ash concrete. A reference plain portland cement concrete was proportioned to obtain 28-day strength of 41 MPa. Concrete mixtures were also proportioned to have two levels of cement replacements (50 and 70%) with an ASTM Class C fly ash. Abrasion tests were carried out using the rotating cutter method

T. R. Naik; S. S. Singh; M. M. Hossain

1994-01-01

457

ABRASIVE FLOW MACHINING WITH ADDITIONAL CENTRIFUGAL FORCE APPLIED TO THE MEDIA  

Microsoft Academic Search

Abrasive flow machining (AFM) is one of the important non-traditional metal finishing technologies which was introduced during the late 1960s. The process has found applications in a wide range of fields such as aerospace, defence, surgical and tool manufacturing industries. Recently, an effort has been made towards the performance improvement of this process by applying centrifugal force on the abrasive

R. S. Walia; H. S. Shan; P. Kumar

2006-01-01

458

Influence of heat and thermochemical treatment on abrasion resistance of structural and tool steels  

Microsoft Academic Search

Abrasive wear is responsible for intensive degradation of machine parts or tools. This process starts as an interaction between hard, mostly mineral, particles and the working surface. Methods of increasing the lifetime are based on application of abrasion resistant materials or creation of hard, wear-resistant surface layers or coatings on the surfaces of machine parts or tools. Carbon and low-alloy

J. Suchánek; V. Kuklík

2009-01-01

459

A study on practical use of underwater abrasive water jet cutting  

Microsoft Academic Search

The practicality of underwater abrasive water jet cutting technology was studied in experiments. A study of abrasives in slurried form showed that optimum polymer concentration can be selected to suit underwater conditions. For the long-distance transport of slurry from the ocean surface to the ocean floor, a direct supply system by hose proved to be practical. This system takes advantage

Hitoshi Yamaguchi; Kenji Demura

1993-01-01

460

Experimental Studies on Mechanism of Material Removal in Abrasive Flow Machining Process  

Microsoft Academic Search

In this article, the mechanism of material removal (MR) in Abrasive Flow Machining (AFM) process has been studied. Representative components of pure Aluminum and Brass were processed by AFM under similar process conditions. The processed surfaces were analyzed with the help of Scanning Electron Microscopy (SEM). SEM photographs reveal noticeable difference between abrasion patterns produced on the processed surfaces of

Sehijpal Singh; H. S. Shan; Pradeep Kumar

2008-01-01

461

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

Microsoft Academic Search

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

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

1977-01-01

462

Laser abrasion for cosmetic and medical treatment of facial actinic damage  

Microsoft Academic Search

Previous studies have shown the carbon dioxide (COâ) laser to be effective in the treatment of actinic cheilitis. After COâ laser abrasion, normal skin and marked cosmetic improvement of the lip were noted. In our study, twenty-three patients were treated with COâ laser abrasions for cosmetic improvement of facial lines and actinic changes. Pre- and postoperative histopathologic examinations were made

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

1989-01-01

463

Friction characterisation of polymers abrasion (UHWMPE) during scratch tests: single and multi-asperity contact  

Microsoft Academic Search

An understanding of abrasion resistance and the associated surfaces deformation mechanisms is of primary importance in materials engineering and design [Wear (1998)].Instrumented scratch testing has proven to be a useful tool for the characterisation of the abrasion resistance of material. Although most studies on scratch resistance have been conducted for metals, assuming a purely plastic behaviour, recent studies focus on

S Ducret; C Pailler-Mattéi; V Jardret; R Vargiolu; H Zahouani

2003-01-01

464

Process monitoring evaluation and implementation for the wood abrasive machining process.  

PubMed

Wood processing industries have continuously developed and improved technologies and processes to transform wood to obtain better final product quality and thus increase profits. Abrasive machining is one of the most important of these processes and therefore merits special attention and study. The objective of this work was to evaluate and demonstrate a process monitoring system for use in the abrasive machining of wood and wood based products. The system developed increases the life of the belt by detecting (using process monitoring sensors) and removing (by cleaning) the abrasive loading during the machining process. This study focused on abrasive belt machining processes and included substantial background work, which provided a solid base for understanding the behavior of the abrasive, and the different ways that the abrasive machining process can be monitored. In addition, the background research showed that abrasive belts can effectively be cleaned by the appropriate cleaning technique. The process monitoring system developed included acoustic emission sensors which tended to be sensitive to belt wear, as well as platen vibration, but not loading, and optical sensors which were sensitive to abrasive loading. PMID:22163477

Saloni, Daniel E; Lemaster, Richard L; Jackson, Steven D

2010-11-18

465

LTC American`s, Inc. vacuum blasting machine: Baseline report  

SciTech Connect

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.

NONE

1997-07-31

466

A computational model of blast loading on the human eye.  

PubMed

Ocular injuries from blast have increased in recent wars, but the injury mechanism associated with the primary blast wave is unknown. We employ a three-dimensional fluid-structure interaction computational model to understand the stresses and deformations incurred by the globe due to blast overpressure. Our numerical results demonstrate that the blast wave reflections off the facial features around the eye increase the pressure loading on and around the eye. The blast wave produces asymmetric loading on the eye, which causes globe distortion. The deformation response of the globe under blast loading was evaluated, and regions of high stresses and strains inside the globe were identified. Our numerical results show that the blast loading results in globe distortion and large deviatoric stresses in the sclera. These large deviatoric stresses may be indicator for the risk of interfacial failure between the tissues of the sclera and the orbit. PMID:23591604

Bhardwaj, Rajneesh; Ziegler, Kimberly; Seo, Jung Hee; Ramesh, K T; Nguyen, Thao D

2013-04-17

467

Otologic blast injuries due to the Kenya embassy bombing.  

PubMed

Otologic injuries are frequently associated with large blasts. On August 7, 1998, a large truck bomb exploded next to the U.S. Embassy in Nairobi, Kenya. Initial patient findings and care are reviewed. Five months later, an otologic screening and care mission was then sent to comprehensively screen all remaining blast victims on site in Nairobi and to determine degree of persistent injury. Surgical care appropriate for an outpatient environment was provided. Five of 14 tympanic membranes without intervention failed to heal, while 3 of 3 with previous intervention had. Blast injury severity did not correlate to distance from blast epicenter. This may be due to channeling of the blast through the embassy building and an unpredictable pattern of blast overpressure within the building. It is recommended that comprehensive otologic screening be performed after blast events to identify occult injuries and improve outcomes. Early intervention for tympanic membrane perforation (suctioning, eversion of perforations, and paper patch) is recommended. PMID:15605933

Helling, Eric Robert

2004-11-01

468

Blast noise classification with common sound level meter metrics.  

PubMed

A common set of signal features measurable by a basic sound level meter are analyzed, and the quality of information carried in subsets of these features are examined for their ability to discriminate military blast and non-blast sounds. The analysis is based on over 120?000 human classified signals compiled from seven different datasets. The study implements linear and Gaussian radial basis function (RBF) support vector machines (SVM) to classify blast sounds. Using the orthogonal centroid dimension reduction technique, intuition is developed about the distribution of blast and non-blast feature vectors in high dimensional space. Recursive feature elimination (SVM-RFE) is then used to eliminate features containing redundant information and rank features according to their ability to separate blasts from non-blasts. Finally, the accuracy of the linear and RBF SVM classifiers is listed for each of the experiments in the dataset, and the weights are given for the linear SVM classifier. PMID:22894205

Cvengros, Robert M; Valente, Dan; Nykaza, Edward T; Vipperman, Jeffrey S

2012-08-01

469

The design, implementation, and evaluation of mpiBLAST  

SciTech Connect

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.

Darling, A. E. (Aaron E.); Carey, L. (Lucas); Feng, W. C. (Wu-Chun)

2003-01-01

470

Abrasion resistance of concrete as influenced by inclusion of fly ash  

SciTech Connect

This research was conducted to evaluate abrasion resistance of high-volume fly ash concrete. A reference plain portland cement concrete was proportioned to obtain 28-day strength of 41 MPa. Concrete mixtures were also proportioned to have two levels of cement replacements (50 and 70%) with an ASTM Class C fly ash. Abrasion tests were carried out using the rotating cutter method as per ASTM C944. In this work all the concrete specimens made either with or without fly ash passed the abrasion resistance requirements per ASTM C-779, Procedure B. An accelerated test method was also developed to evaluate abrasion resistance of concrete. This method used the rotary cutter device having dressing wheels equipped with smaller size washers. A measured amount of standard Ottawa sand was added to the surface being abraded at one minute intervals. The accelerated test results exhibited lower abrasion resistance for high-volume fly ash concrete systems relative to no-fly ash concrete.

Naik, T.R.; Singh, S.S.; Hossain, M.M. (Univ. of Wisconsin, Milwaukee, WI (United States). College of Engineering and Applied Science)

1994-01-01

471

Submucous implant of abrasive dental materials in rat tongues: clinical and histological evaluation.  

PubMed

This study evaluated the clinical and histological manifestations produced by the submucuous implant of abrasive dental materials in the rat tongue. A total of 128 rats were divided into 4 groups of 32 rats each, according to the material selected for the implant: Herjos-F prophylactic paste both in its normal composition as well as lacking its abrasive components, SS White pumice stone and the abrasive powder of the 3M finishing and polishing sandpaper. The specimens were submitted to clinical and histological analyses at 30, 60, 90 and 120 days. After 90 days, the formation of nodular lesions in animals implanted with materials containing abrasive substances was observed. Histologically, these materials produced marked chronic granulomatous reactions. Herjos-F prophylactic paste produced the greatest reaction. However, without the abrasive components, this paste caused the mildest tissue reactions, with no inflammatory response, that was seen in a progressively greater number of cases after 90 days. PMID:12238799

Pistóia, Alexandre Dorneles; de Figueiredo, Maria Antonia Zancanaro

2002-01-01

472

Abrasive rolling effects on material removal and surface finish in chemical mechanical polishing analyzed by molecular dynamics simulation  

NASA Astrophysics Data System (ADS)

In an abrasive chemical mechanical polishing (CMP) process, materials were considered to be removed by abrasive sliding and rolling. Abrasive sliding has been investigated by many molecular dynamics (MD) studies; while abrasive rolling was usually considered to be negligible and therefore was rarely investigated. In this paper, an MD simulation was used to study the effects of abrasive rolling on material removal and surface finish in the CMP process. As the silica particle rolled across the silicon substrate, some atoms of the substrate were dragged out from their original positions and adhered to the silica particle, leaving some atomic vacancies on the substrate surface. Meanwhile, a high quality surface could be obtained. During the abrasive rolling process, the influencing factors of material removal, e.g., external down force and driving force, were also discussed. Finally, MD simulations were carried out to examine the effects of abrasive sliding on material removal under the same external down force as abrasive rolling. The results showed that the ability of abrasive rolling to remove material on the atomic scale was not notably inferior to that of abrasive sliding. Therefore, it can be proposed that both abrasive sliding and rolling play important roles in material removal in the abrasive CMP of the silicon substrate.

Si, Lina; Guo, Dan; Luo, Jianbin; Lu, Xinchun; Xie, Guoxin

2011-04-01

473

Shougang No. 2 blast furnace enlargement  

SciTech Connect

Shougang is expanding to become a 10 million ton/year steel plant in 1995. In 1990, the capacity of Shougang No. 2 blast furnace was enlarged from 1,327 to 1,726 cu meters. The project consisted of building a new furnace on the old site while maintaining the operation of the old furnace. The project was completed in 188 calendar days, 3 days ahead of schedule. Shougang has a large, comprehensive technical force that includes design, construction and production. Most of the equipment and instrumentation, both mechanical and electrical, were fabricated by Shougang personnel. The future increase in capacity of No. 1, 3 and 4 blast furnaces will exceed that of No. 2 furnace.

Wang, Z.Z. (Shougang Iron and Steel Corp., Beijing (China))

1994-09-01

474

A Phased Array Approach to Rock Blasting  

SciTech Connect

A series of laboratory-scale simultaneous two-hole shots was performed in a rock simulant (mortar) to record the shock wave interference patterns produced in the material. The purpose of the project as a whole was to evaluate the usefulness of phased array techniques of blast design, using new high-precision delay technology. Despite high-speed photography, however, we were unable to detect the passage of the shock waves through the samples to determine how well they matched the expected interaction geometry. The follow-up mine-scale tests were therefore not conducted. Nevertheless, pattern analysis of the vectors that would be formed by positive interference of the shockwaves from multiple charges in an ideal continuous, homogeneous, isotropic medium indicate the potential for powerful control of blast design, given precise characterization of the target rock mass.

Leslie Gertsch; Jason Baird

2006-07-01

475

Acute blast injury reduces brain abeta in two rodent species.  

PubMed

Blast-induced traumatic brain injury (TBI) has been a major cause of morbidity and mortality in the conflicts in Iraq and Afghanistan. How the primary blast wave affects the brain is not well understood. In particular, it is unclear whether blast injures the brain through mechanisms similar to those found in non-blast closed impact injuries (nbTBI). The ?-amyloid (A?) peptide associated with the development of Alzheimer's disease is elevated acutely following TBI in humans as well as in experimental animal models of nbTBI. We examined levels of brain A? following experimental blast injury using enzyme-linked immunosorbent assays for A? 40 and 42. In both rat and mouse models of blast injury, rather than being increased, endogenous rodent brain A? levels were decreased acutely following injury. Levels of the amyloid precursor protein (APP) were increased following blast exposure although there was no evidence of axonal pathology based on APP immunohistochemical staining. Unlike the findings in nbTBI animal models, levels of the ?-secretase, ?-site APP cleaving enzyme 1, and the ?-secretase component presenilin-1 were unchanged following blast exposure. These studies have implications for understanding the nature of blast injury to the brain. They also suggest that strategies aimed at lowering A? production may not be effective for treating acute blast injury to the brain. PMID:23267342

De Gasperi, Rita; Gama Sosa, Miguel A; Kim, Soong Ho; Steele, John W; Shaughness, Michael C; Maudlin-Jeronimo, Eric; Hall, Aaron A; Dekosky, Steven T; McCarron, Richard M; Nambiar, Madhusoodana P; Gandy, Sam; Ahlers, Stephen T; Elder, Gregory A

2012-12-21

476

Blast waves and how they interact with structures.  

PubMed

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

Cullis, I G

2001-02-01

477

Extracellular cyclophilin A protects against blast-induced neuronal injury.  

PubMed

Blast-induced traumatic brain injury (TBI) and subsequent neurobehavioral deficits are major disabilities suffered by the military and civilian population worldwide. Rigorous scientific research is underway to understand the mechanism of blast TBI and thereby develop effective therapies for protection and treatment. By using an in vitro shock tube model of blast TBI with SH-SY5Y human neuroblastoma cells, we have demonstrated that blast exposure leads to neurobiological changes in an overpressure and time dependent manner. Paradoxically, repeated blast exposures resulted in less neuronal injury compared to single blast exposure and suggested a potential neuroprotective mechanism involving released cyclophilin A (CPA). In the present study, we demonstrate accumulation of CPA in the culture medium after repeated blast exposures supporting the notion of extracellular CPA mediated neuroprotection. Post-exposure treatment of the cells with purified recombinant CPA caused significant protection against blast-induced neuronal injury. Furthermore, repeated blast exposure was associated with phosphorylation of the proteins ERK1/2 and Bad suggesting a potential mechanism of neuroprotection by extracellular CPA and may aid in the development of targeted therapies for protection against blast-induced TBI. PMID:23511555

Arun, Peethambaran; Abu-Taleb, Rania; Valiyaveettil, Manojkumar; Wang, Ying; Long, Joseph B; Nambiar, Madhusoodana P

2013-03-17

478

Paint removal and surface cleaning using ice particles  

NASA Astrophysics Data System (ADS)

Research into the possibility of using ice particles as a blast medium was first initiated at Defence Research Establishment Pacific (DREP) in an effort to develop a more environmentally acceptable paint removal method. A paint removal process was also required that could be used in areas where normal grit blasting could not be used due to the possibility of the residual blasting grit contaminating machinery and other equipment. As a result of this research a commercial ice blasting system was developed by RETECH. This system is now being used to remove paint from substrates that cannot be easily blasted by conventional techniques and also to clean soiled or contaminated surfaces. The problems involved in the development of an ice blast system and its components and their functions are described. Due to the complexity of paint removal using ice blasting, parameters such as air pressure, ice particle size and ice particle flow rate were studied and adjusted to suit the nature of the particular coating and substrate of interest. The mechanism of paint removal by ice particles has also been investigated. A theoretical model has been developed to explain the different paint removal mechanisms such as erosion by abrasion and erosion by fracture as they relate to ice blasting. Finally, the use of ice blasting to removal paint from a variety of substrates is presented as well as examples of surface cleaning and surface decontamination.

Foster, Terry; Visaisouk, S.

1995-04-01

479

Paint removal and surface cleaning using ice particles  

NASA Astrophysics Data System (ADS)

Research into the possibility of using ice particles as a blast medium was first initiated at Defence Research Establishment Pacific (DREP) in an effort to develop a more environmentally acceptable paint removal method. A paint removal process was also required that could be used in areas where normal grit blasting could not be used due to the possibility of the residual blasting grit contaminating machinery and other equipment. As a result of this research a commercial ice blasting system was developed by RETECH. This system is now being used to remove paint from substrates that cannot be easily blasted by conventional techniques and also to clean soiled or contaminated surfaces. The problems involved in the development of an ice blast system, and its components and their functions are described. Due to the complexity of paint removal using ice blasting, parameters such as air pressure, ice particle size and ice particle flow rate were studied and adjusted to suit the nature of the particular coating and substrate of interest. The mechanism of paint removal by ice particles has also been investigated. A theoretical model has been developed to explain the different paint removal mechanisms such as erosion by abrasion and erosion by fracture as they relate to ice blasting. Finally, the use of ice blasting to removal paint from a variety of substrates is presented as well as examples of surface cleaning and surface decontamination.

Foster, Terry; Visaisouk, S.

1993-03-01

480

10. Bruising, abrasions and lacerations: minor injuries in children I.  

PubMed

Minor injuries in children (those that could reasonably be expected to heal with minimal medical intervention) are extremely common. The possibility of more serious injuries should be considered and excluded early. Successful examination requires gaining the child's trust, relieving pain early, and using a flexible and creative examination technique. Bruising may suggest a more serious underlying injury, or the bruising pattern may indicate non-accidental injury or a bleeding disorder. Superficial abrasions and lacerations can be safely cleaned with good quality water, and all foreign material should be removed. Deeper wounds with suspected damage to nerves, tendons or circulation need formal exploration under a general anaesthetic. Good local anaesthesia can be produced by topical preparations, and many wounds can be closed with tissue adhesives with an excellent cosmetic result. Antibiotics should be prescribed for specific circumstances, such as wounds with extensive contamination or tissue damage, and all children with injuries should be checked for adequate tetanus cover for prophylaxis. PMID:15938689

Young, Simon J; Barnett, Peter L J; Oakley, Ed A

2005-06-01

481

Statistical Analysis of Magnetic Abrasive Finishing (MAF) On Surface Roughness  

NASA Astrophysics Data System (ADS)

Magnetic assisted finishing is one of the nontraditional methods of polishing that recently has been attractive for the researchers. This paper investigates the effects of some parameters such as rotational speed of the permanent magnetic pole, work gap between the permanent pole and the work piece, number of the cycles and the weight of the abrasive particles on aluminum surface plate finishing. The three levels full factorial method was used as the DOE technique (design of experiments) for studying the selected factors. Analysis of Variance (ANOVA) has been used to determine significant factors and also to obtain an equation based on data regression. Experimental results indicate that for a change in surface roughness ?Ra, number of cycles and working gap are found to be the most significant parameters followed by rotational speed and then weight of powders.

Givi, Mehrdad; Tehrani, Alireza Fadaei; Mohammadi, Aminollah

2010-06-01

482

Blast resistance of unidirectional fiber reinforced composites  

Microsoft Academic Search

Three-dimensional transient deformations of a laminate comprised of several unidirectional fiber reinforced layers perfectly bonded to each other and subjected to a blast load are analyzed by the finite element method with an in-house developed, verified and fully validated code with rate-dependent damage evolution equations for anisotropic bodies. The continuum damage mechanics approach employing three internal variables is used to

R. C. Batra; N. M. Hassan

2008-01-01

483

Laboratory Blast Simulator for Composite Materials Characterization  

Microsoft Academic Search

\\u000a Blasts and explosives have raised serious concerns in recent years due to the fatal injury and catastrophic damage they have\\u000a caused in the combat zones and due to industrial accidents. Owing to their lightweight and complex damage process, fiber-reinforced\\u000a composite materials have been found to have higher energy absorption capability and to be able to generate less lethal debris\\u000a than

Guojing Li; Dahsin Liu

484

Protecting blasting operations from possible lawsuits  

SciTech Connect

Any blasting violations, whether detected by an inspector, or undetected and therefore unwritten, will likely come back to haunt you if there is a lawsuit stemming from an alleged personal injury or property damage. These violations can be used by a plaintiff's attorney to show that the operation was not conducted according to law and not in a professional manner. This could effect the amount of punitive damages awarded on top of the actual loss award. This article describes the operations.

Ludwiczak, J.T.

1987-05-01

485

Reactive Blast Waves from Composite Charges  

Microsoft Academic Search

Investigated here is the performance of composite explosives - measured in terms of the blast wave they drive into the surrounding environment. The composite charge configuration studied here was a spherical booster (1\\/3 charge mass), surrounded by aluminum (Al) powder (2\\/3 charge mass) at an initial density of = 0.604 g\\/cc. The Al powder acts as a fuel but does

A L Kuhl; J B Bell; V E Beckner

2009-01-01

486

The Blast Polarized H\\/d Target  

Microsoft Academic Search

The Bates Large Acceptance Spectrometer Toroid (BLAST)1 is a detector designed to study the spin dependent electromagnetic response of few-body nuclei at momentum transfers up to 1 (GeV\\/c)2. The strength of the experiment lies in its unique combination of large acceptance spectrometer, highly polarized electron beam, and dilution free internal gas targets. The Atomic Beam Source (ABS)2,3 which operated in

H. Kolster; C. Crawford; K. McIlhany; N. Meitanis; R. Milner; T. Wise; V. Ziskin

2002-01-01

487

Centrifugal shot blasting. Innovative technology summary report  

SciTech Connect

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.

Not Available

1999-07-01

488

Vehicle overturning vulnerability from air blast loads  

NASA Astrophysics Data System (ADS)

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.

Robinson, R. R.; Napadensky, H.; Longinow, A.

1984-08-01

489

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

SciTech Connect

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.

Kosel, T.H.

1984-08-14

490

Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach.  

PubMed

Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbr number equals the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. Basically, the StAbr number concept describes the blending condition of the dry-mixing system. The concept has been applied to investigate the relevance of process parameters on agglomerate abrasion in tumbling blenders. Here, process parameters such as blender rotational speed and relative fill volumes were investigated. In this study, the StAbr approach revealed a transition point between abrasion rate behaviors. Below this transition point, a blending condition exists where agglomerate abrasion is dominated by the kinetic energy density of the powder blend. Above this transition point, a blending condition exists where agglomerates show (undesirable) slow abrasion rates. In this situation, the blending condition is mainly determined by the high fill volume of the filler. PMID:23250711

Willemsz, Tofan A; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

2012-12-19

491

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

SciTech Connect

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.

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

2009-01-01

492

Rock damage control in bedrock blasting excavation for a nuclear power plant  

Microsoft Academic Search

Drill and blast is a major method for bedrock excavation in nuclear power plant engineering. Under blasting excavation, blast-induced vibration propagates in rock mass and induces damage to surrounding rock. Studying the characteristics of wave propagation and blast-induced damage to rock mass is most important to restrict the damage extension. In the present paper, in support of the bedrock blasting

Li Haibo; Xia Xiang; Li Jianchun; Zhao Jian; Liu Bo; Liu Yaqun

2011-01-01

493

Abrasive wear by coal-fueled diesel engine and related particles  

SciTech Connect

The development of commercially viable diesel engines that operate directly on pulverized coal-fuels will require solution to the problem of severe abrasive wear. The purpose of the work described in this report was to investigate the nature of the abrasive wear problem. Analytical studies were carried out to determine the characteristics of the coal-fuel and associated combustion particles responsible for abrasion. Laboratory pinon-disk wear tests were conducted on oil-particle mixtures to determine the relationship between wear rate and a number of different particle characteristics, contact parameters, specimen materials properties, and other relevant variables.

Ives, L.K. (National Inst. of Standards and Technology, Gaithersburg, MD (United States))

1992-09-01

494

Chemical Mechanical Polishing of Ge2Sb2Te5 Using Abrasive-Free Solutions of Iron Trichloride  

NASA Astrophysics Data System (ADS)

Chemical mechanical polishing (CMP) of amorphous Ge2Sb2Te5 (GST) is studied using aqueous solutions of iron trichloride (FeCl3) as possible abrasive-free slurries. The polishing performance of abrasive-free solutions is compared with abrasive-containing (3wt% colloidal silica) slurry in terms of polishing rate and surface quality. The experimental results indicate that the abrasive-free solutions have a higher polishing rate and better surface quality. In order to further investigate the polishing mechanism, post-CMP GST films using the abrasive-free solutions and abrasive-containing slurry are characterized by x-ray photoelectron spectroscopy. Finally, it is verified that the abrasive-free solutions have no influence on the electrical property of the post-CMP GST films through the resistivity test.

Yan, Wei-Xia; Wang, Liang-Yong; Zhang, Ze-Fang; He, Ao-Dong; Zhong, Min; Liu, Wei-Li; Wu, Liang-Cai; Song, Zhi-Tang

2012-03-01

495

An adaptive low complexity and high performance BLAST detection algorithm  

NASA Astrophysics Data System (ADS)

It is well known that MIMO channel capacity was greatly improved by used of BLAST code, but the existing methods still have the decoding complexity and precision problem. This paper analyzes the advantage and disadvantage of the present detection algorithms for the BLAST system. An adaptive BLAST decoding algorithm with lower decoding complexity is proposed. The simulations show that the adaptive detection can achieve the moderate tradeoff between complexity and performance.

Wang, Desheng; Fu, Jie; Zhu, Guangxi; Liu, Deming

2009-08-01

496

Performance Evaluation of the V-BLAST Coset Detector  

Microsoft Academic Search

In this paper we address the analytical performance evaluation of the V-BLAST coset detector (CD). The V-BLAST-CD is a sub-optimal detector for spatial multiplexing MIMO systems using non-binary constellations. In the V-BLAST-CD the decision on the transmitted vector is taken by applying the maximum likelihood detector on a list of candidate vectors containing only a subset of the possible transmitted

M. Magarini; A. Spalvieri

2005-01-01

497

Durability of traditional plasters with respect to blast furnace slag-based plaster  

SciTech Connect

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.

Cerulli, T.; Pistolesi, C.; Maltese, C.; Salvioni, D

2003-09-01

498

Bomb blast injury: effect on middle and inner ear  

Microsoft Academic Search

Objective  To study the symptomatology, clinical findings and the effects of blast injury on middle and inner ear in survivors of bomb\\u000a blast.\\u000a \\u000a Settings City of Mumbai, India.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The study group consisted of 52 patients exposed to the bomb blast that occurred on 25th August 2003.\\u000a \\u000a \\u000a \\u000a Result and Analysis  The distance of the victim from the blast site has no major infiuence

M. V. Jagade; R. A. Patil; I. S. Suhail; P. Kelkar; S. Nemane; J. Mahendru; V. Kalbande; P. Kewle

2008-01-01

499

Transient changes in neuronal cell membrane permeability after blast exposure.  

PubMed

The biochemical mechanisms of explosive blast-induced traumatic brain injury and the subsequent long-term neurobehavioral abnormalities are still not completely understood. We studied the biochemical mechanism of blast traumatic brain injury using our recently reported in-vitro model system with a shock tube. Primary blast exposure of in-vitro models leads to neurobiological changes in an overpressure dose-dependent and time-dependent manner. Lactate dehydrogenase was released significantly into the extracellular medium without cell death after blast exposure, indicating compromised cell membrane integrity. We further explored the integrity of cell membrane after blast exposure by fluorescent dye uptake/release techniques in SH-SY5Y human neuroblastoma cells. Our data indicate that blast exposure leads to an overpressure-dependent transient increase in the release of preloaded calcein AM into the culture medium with proportional intracellular decrease. Uptake of an extracellular nucleic acid-binding dye TO-PRO-3 iodide was also increased significantly after blast exposure, indicating that the increased molecular transport is bidirectional and nuclear membrane integrity is also affected by blast exposure. These results suggest that blast exposure perturbs the integrity of the neuronal cell membrane, leading to increased bidirectional transport of molecules--a potential mechanism that can lead to traumatic brain injury. PMID:22426026

Arun, Peethambaran; Abu-Taleb, Rania; Valiyaveettil, Manojkumar; Wang, Ying; Long, Joseph B; Nambiar, Madhusoodana P

2012-04-18

500

Mechanisms of hearing loss after blast injury to the ear.  

PubMed

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

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

2013-07-01