Science.gov

Sample records for abrasive water-jet cutting

  1. Fatigue Testing of Abrasive Water Jet Cut Titanium

    SciTech Connect

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

    2009-06-08

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

  2. An acoustic emission study of cutting bauxite refractory ceramics by abrasive water jets

    NASA Astrophysics Data System (ADS)

    Momber, A. W.; Mohan, R. S.; Kovacevic, R.

    1999-08-01

    This article discusses the material removal process in bauxite refractory ceramics cut by abrasive water jets. Several parameters of the process were changed during the experiments. The experiments were monitored online by the acoustic emission (AE) technique. It was found that AE signals are able to sense the material removal process as well as the machining performances very reliably. Unsteady material removal mode consisting of matrix removal and intergranular fracture was very well represented in the AE signals by an unsteady time dependent signal type characterized by burst emissions and a frequency domain signal associated with a twin-peak shape. The particular characteristics of the signal depend on the energy involved in the process.

  3. Testing of Alternative Abrasives for Water-Jet Cutting at C Tank Farm

    SciTech Connect

    Krogstad, Eirik J.

    2013-08-01

    Legacy waste from defense-related activities at the Hanford Site has predominantly been stored in underground tanks, some of which have leaked; others may be at risk to do so. The U.S. Department of Energy’s goal is to empty the tanks and transform their contents into more stable waste forms. To do so requires breaking up, and creating a slurry from, solid wastes in the bottoms of the tanks. A technology developed for this purpose is the Mobile Arm Retrieval System. This system is being used at some of the older single shell tanks at C tank farm. As originally planned, access ports for the Mobile Arm Retrieval System were to be cut using a high- pressure water-jet cutter. However, water alone was found to be insufficient to allow effective cutting of the steel-reinforced tank lids, especially when cutting the steel reinforcing bar (“rebar”). The abrasive added in cutting the hole in Tank C-107 was garnet, a complex natural aluminosilicate. The hardness of garnet (Mohs hardness ranging from H 6.5 to 7.5) exceeds that of solids currently in the tanks, and was regarded to be a threat to Hanford Waste Treatment and Immobilization Plant systems. Olivine, an iron-magnesium silicate that is nearly as hard as garnet (H 6.5 to 7), has been proposed as an alternative to garnet. Pacific Northwest National Laboratory proposed to test pyrite (FeS2), whose hardness is slightly less (H 6 to 6.5) for 1) cutting effectiveness, and 2) propensity to dissolve (or disintegrate by chemical reaction) in chemical conditions similar to those of tank waste solutions. Cutting experiments were conducted using an air abrader system and a National Institute of Standards and Technology Standard Reference Material (SRM 1767 Low Alloy Steel), which was used as a surrogate for rebar. The cutting efficacy of pyrite was compared with that of garnet and olivine in identical size fractions. Garnet was found to be most effective in removing steel from the target; olivine and pyrite were less

  4. Machining human dentin by abrasive water jet drilling.

    PubMed

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin.

  5. Machining human dentin by abrasive water jet drilling.

    PubMed

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin. PMID:24642975

  6. A review on nozzle wear in abrasive water jet machining application

    NASA Astrophysics Data System (ADS)

    Syazwani, H.; Mebrahitom, G.; Azmir, A.

    2016-02-01

    This paper discusses a review on nozzle wear in abrasive water jet machining application. Wear of the nozzle becomes a major problem since it may affect the water jet machining performance. Design, materials, and life of the nozzle give significance effect to the nozzle wear. There are various parameters that may influence the wear rate of the nozzle such as nozzle length, nozzle inlet angle, nozzle diameter, orifice diameter, abrasive flow rate and water pressure. The wear rate of the nozzle can be minimized by controlling these parameters. The mechanism of wear in the nozzle is similar to other traditional machining processes which uses a cutting tool. The high pressure of the water and hard abrasive particles may erode the nozzle wall. A new nozzle using a tungsten carbide-based material has been developed to reduce the wear rate and improve the nozzle life. Apart from that, prevention of the nozzle wear has been achieved using porous lubricated nozzle. This paper presents a comprehensive review about the wear of abrasive water jet nozzle.

  7. Dressing of diamond grinding wheels by abrasive water jet for freeform optical surface grinding

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Yao, Peng; Li, Chengwu; Huang, Chuanzhen; Wang, Jun; Zhu, Hongtao; Liu, Zengwen

    2014-08-01

    During the ultra-precision grinding of a large aperture mirror made of RB-SiC, the grinding wheel becomes dull rapidly, which will lead to an increase of grinding force and a decrease of grinding ratio. In this paper, diamond grinding sticks were dressed with micro SiC abrasive water jet and water jet. Through single factorial experiments, the influence of jet pressure on the dressing performance was investigated. To analyze and evaluate the effect of dressing quantitatively, the 3D roughness and the wheel topography were measured and compared with laser scanning confocal microscope before and after dressing. The experimental results show that the abrasive grains are well protruded from binder and the distribution of the abrasive grains becomes uniform after dressing by abrasive water jet when the dressing parameters are properly selected. The dressing performance of abrasive water jet is much better than water jet. For dressing ultra-fine grit size wheels, the abrasive size of the jet should be smaller than the wheel grit size to achieve a better result. The jet pressure is an obvious influence factor of the surface topography.

  8. Studies on parametric optimization for abrasive water jet machining of Al7075-TiB2 in-situ composite

    NASA Astrophysics Data System (ADS)

    Kavya, J. T.; Keshavamurthy, R.; Pradeep Kumar, G. S.

    2016-09-01

    The study focuses on optimization and determination of significant process parameter for Abrasive Water Jet Machining of Al7075-TiB2metal matrix composite. Al-TiB2 metal matrix composite is synthesized by stir casting using in-situ technique. Optimization of machining parameters is done using Taguchi's L25orthogonal array for the experimental trials, with cutting speed, stand-off distance and Abrasive Flow rate as input parameters at five different levels. Analysis Of Variance (ANOVA) method is used for identifying the effect of machining parameters on volumetric material removal rate, surface roughness and dimensional accuracy. Then the results are validated by conducting verification experiments.

  9. [Water jet cutting for bones and bone cement--parameter study of possibilities and limits of a new method].

    PubMed

    Honl, M; Rentzsch, R; Lampe, F; Müller, V; Dierk, O; Hille, E; Louis, H; Morlock, M

    2000-09-01

    Water jet techniques have been used in industrial cutting, drilling and cleaning applications for more than 30 years. Plain water is typically used for the cutting of non-metallic materials. The addition of abrasive substances to the stream allows almost any material to be cut. The first medical applications were reported in the early 1980s, when the water jet was used to cut organs. The present study investigates the use of water jet cutting technology for endoprosthesis revision surgery. Bone and PMMA (polymethylmethacrylate) samples were cut at different pressures using an industrial water jet cutting device. Using plain water at 400 bar, PMMA was cut selectively without damaging the bone; above 400 bar, bone was also cut, but the cutting depths in PMMA were significantly greater (p < 0.05). Adding a water-soluble abrasive disaccharide to the water results in a significantly higher removal rate for both materials (p < 0.05), but selectivity is lost, although the differences in cutting depth between the two materials was significant (p < 0.05). With an abrasive, the quality of the cut was better for both materials. The water jet technology--in particular the abrasive technique--can be used to cut biomaterials such as bone and bone cement. The diameter of the jet is a great advantage when working in the confined area at the prosthesis interface. The cutting process is essentially cold, thus eliminating a thermal effect, and the jet reaction forces are relatively low. Accurate manipulation of the hydro jet nozzle is possible both manually and by robot. The results obtained show that it is possible to remove prostheses with this cutting technique, rapidly and with little damage to the surrounding tissue. Problem areas are the development of sterile pumps and the "depth control" of the jet.

  10. Ultra-fast X-ray particle velocimetry measurements within an abrasive water jet

    NASA Astrophysics Data System (ADS)

    Balz, R.; Mokso, R.; Narayanan, C.; Weiss, D. A.; Heiniger, K. C.

    2013-03-01

    Ultra-fast X-ray velocimetry measurements were taken to measure velocities and spatial positions of individual abrasive particles within the solid-liquid-gaseous three-phase flow of a high-pressure injection method-based abrasive water jet (AWJ). A synchrotron X-ray source provided sufficient photon flux to take double-frame images of the AWJ with an inter-frame time interval of 5 μs. Abrasive particles with a Sauter mean diameter of 265.5 μm were detected by a scintillator optically coupled to a gated image intensifier and a high-speed camera running at a frame rate of 11,250 Hz. A commercially available particle tracking velocimetry software was used to process the acquired images and evaluate the spatial positions and velocities of abrasive particles as a function of water pressure and abrasive mass flow. The acquired data show a Gaussian radial distribution of abrasive particles within the AWJ and an almost uniform mean axial velocity, irrespective of water jet velocity and abrasive flow rates. These results are useful to validate theoretical models for the momentum/energy transfer in AWJ, to provide input for abrasion/erosion models, to further understand and advance the AWJ process, and to develop new process opportunities such as AWJ milling.

  11. High pressure water jet cutting and stripping

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.; Babai, Majid K.

    1991-01-01

    High pressure water cutting techniques have a wide range of applications to the American space effort. Hydroblasting techniques are commonly used during the refurbishment of the reusable solid rocket motors. The process can be controlled to strip a thermal protective ablator without incurring any damage to the painted surface underneath by using a variation of possible parameters. Hydroblasting is a technique which is easily automated. Automation removes personnel from the hostile environment of the high pressure water. Computer controlled robots can perform the same task in a fraction of the time that would be required by manual operation.

  12. An investigation on co-axial water-jet assisted fiber laser cutting of metal sheets

    NASA Astrophysics Data System (ADS)

    Madhukar, Yuvraj K.; Mullick, Suvradip; Nath, Ashish K.

    2016-02-01

    Water assisted laser cutting has received significant attention in recent times with assurance of many advantages than conventional gas assisted laser cutting. A comparative study between co-axial water-jet and gas-jet assisted laser cutting of thin sheets of mild steel (MS) and titanium (Ti) by fiber laser is presented. Fiber laser (1.07 μm wavelength) was utilised because of its low absorption in water. The cut quality was evaluated in terms of average kerf, projected dross height, heat affected zone (HAZ) and cut surface roughness. It was observed that a broad range process parameter could produce consistent cut quality in MS. However, oxygen assisted cutting could produce better quality only with optimised parameters at high laser power and high cutting speed. In Ti cutting the water-jet assisted laser cutting performed better over the entire range of process parameters compared with gas assisted cutting. The specific energy, defined as the amount of laser energy required to remove unit volume of material was found more in case of water-jet assisted laser cutting process. It is mainly due to various losses associated with water assisted laser processing such as absorption of laser energy in water and scattering at the interaction zone.

  13. Water Jetting

    NASA Astrophysics Data System (ADS)

    1985-01-01

    Hi-Tech Inc., a company which manufactures water jetting equipment, needed a high pressure rotating swivel, but found that available hardware for the system was unsatisfactory. They were assisted by Marshall, which had developed water jetting technology to clean the Space Shuttles. The result was a completely automatic water jetting system which cuts rock and granite and removes concrete. Labor costs have been reduced; dust is suppressed and production has been increased.

  14. Performance optimization of water-jet assisted underwater laser cutting of AISI 304 stainless steel sheet

    NASA Astrophysics Data System (ADS)

    Mullick, Suvradip; Madhukar, Yuvraj K.; Roy, Subhransu; Nath, Ashish K.

    2016-08-01

    Recent development of water-jet assisted underwater laser cutting has shown some advantages over the gas assisted underwater laser cutting, as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. Scattering is reported to be a dominant loss mechanism, which depends on the growth of vapor layer at cut front and its removal by water-jet. Present study reports improvement in process efficiency by reducing the scattering loss using modulated laser power. Judicious control of laser pulse on- and off-time could improve process efficiency through restricting the vapor growth and its effective removal by water-jet within the laser on- and off-time, respectively. Effects of average laser power, duty cycle and modulation frequency on specific energy are studied to get an operating zone for maximum efficiency. Next, the variation in laser cut quality with different process parameters are studied within this operating zone using Design of experiment (DOE). Response surface methodology (RSM) is used by implementing three level Box-Behnken design to optimize the variation in cut quality, and to find out the optimal process parameters for desired quality. Various phenomena and material removal mechanism involved in this process are also discussed.

  15. Cost minimizing of cutting process for CNC thermal and water-jet machines

    NASA Astrophysics Data System (ADS)

    Tavaeva, Anastasia; Kurennov, Dmitry

    2015-11-01

    This paper deals with optimization problem of cutting process for CNC thermal and water-jet machines. The accuracy of objective function parameters calculation for optimization problem is investigated. This paper shows that working tool path speed is not constant value. One depends on some parameters that are described in this paper. The relations of working tool path speed depending on the numbers of NC programs frames, length of straight cut, configuration part are presented. Based on received results the correction coefficients for working tool speed are defined. Additionally the optimization problem may be solved by using mathematical model. Model takes into account the additional restrictions of thermal cutting (choice of piercing and output tool point, precedence condition, thermal deformations). At the second part of paper the non-standard cutting techniques are considered. Ones may lead to minimizing of cutting cost and time compared with standard cutting techniques. This paper considers the effectiveness of non-standard cutting techniques application. At the end of the paper the future research works are indicated.

  16. The surface quality of AWJ cut parts as a function of abrasive material reusing rate

    NASA Astrophysics Data System (ADS)

    Schnakovszky, C.; Herghelegiu, E.; Radu, M. C.; Tampu, N. C.

    2015-11-01

    Abrasive water jet cutting (AWJ) has been extensively used during the last years to process a large variety of materials since it offers important advantages as a good quality of the processed surface, without heat affected zones, low environmental impact (no emission of dust or other compounds that endanger the health of the user), small induced mechanical stresses etc. The main disadvantage is the high cost of processing (cost of equipment and consumables). In view of this, the effects of reusing the abrasive material on the quality of processed surface are investigated in this paper. Two steel materials were used: OL 37 (S 235) with large applicability in machine building industry and 2P armor steel used in the arms industry. The reusing rate of the garnet abrasive material was: 0%, 20%, 40%, 60%, 80% and 100%. The quality of processed surface was quantified by the following parameters: width at the jet inlet (Li), width at the jet outlet (Lo), inclination angle (α), deviation from perpendicularity (u) and roughness (Ra).

  17. Dental abrasion as a cutting process.

    PubMed

    Lucas, Peter W; Wagner, Mark; Al-Fadhalah, Khaled; Almusallam, Abdulwahab S; Michael, Shaji; Thai, Lidia A; Strait, David S; Swain, Michael V; van Casteren, Adam; Renno, Waleed M; Shekeban, Ali; Philip, Swapna M; Saji, Sreeja; Atkins, Anthony G

    2016-06-01

    A mammalian tooth is abraded when a sliding contact between a particle and the tooth surface leads to an immediate loss of tooth tissue. Over time, these contacts can lead to wear serious enough to impair the oral processing of food. Both anatomical and physiological mechanisms have evolved in mammals to try to prevent wear, indicating its evolutionary importance, but it is still an established survival threat. Here we consider that many wear marks result from a cutting action whereby the contacting tip(s) of such wear particles acts akin to a tool tip. Recent theoretical developments show that it is possible to estimate the toughness of abraded materials via cutting tests. Here, we report experiments intended to establish the wear resistance of enamel in terms of its toughness and how friction varies. Imaging via atomic force microscopy (AFM) was used to assess the damage involved. Damage ranged from pure plastic deformation to fracture with and without lateral microcracks. Grooves cut with a Berkovich diamond were the most consistent, suggesting that the toughness of enamel in cutting is 244 J m(-2), which is very high. Friction was higher in the presence of a polyphenolic compound, indicating that this could increase wear potential. PMID:27274807

  18. Application of water jet assisted drag bit and pick cutter for the cutting of coal measure rocks. Final technical report. [Tests of combination in different rocks

    SciTech Connect

    Ropchan, D.; Wang, F.D.; Wolgamott, J.

    1980-04-01

    A laboratory investigation was made of the effects of high pressure water jets on the cutting forces of drag bit cutters in sedimentary rocks. A hard and soft sandstone, shale and limestone were tested with commercially obtainable conical and plow type drag bits on the EMI linear cutting machine. About 1200 cuts were made at different bit penetration, jet orientation, and water pressure to determine the reduction of cutting forces on the bit from the use of the water jet. Both independent and interactive cutting was used. The greatest reduction in cutting forces were with both of the sandstones; the drag forces were reduced about 30 percent and the normal forces about 60 percent at 5000 psi water pressure with the nozzle behind the bit. The method was less effective in the shale, except at 10,000 psi water pressure the reduction in drag force was about 55 percent. Of the rocks tested, the limestone was least affected by the water jet. The cutting forces for the plow bit showed continuous change with wear so a machined conical bit was used for most of the testing. Tests with the plow bit did show a large reduction in cutting forces by using the water jet with worn bits. An economic analysis of equipping a drag bit tunnel boring machine indicated that the water jet system could reduce costs per foot in sandstone by up to 40 percent.

  19. Solid Lubrication Fundamentals and Applications. Chapter 5; Abrasion: Plowing and Cutting

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2001-01-01

    Chapter 5 discusses abrasion, a common wear phenomenon of great economic importance. It has been estimated that 50% of the wear encountered in industry is due to abrasion. Also, it is the mechanism involved in the finishing of many surfaces. Experiments are described to help in understanding the complex abrasion process and in predicting friction and wear behavior in plowing and/or cutting. These experimental modelings and measurements used a single spherical pin (asperity) and a single wedge pin (asperity). Other two-body and three-body abrasion studies used hard abrasive particles.

  20. Cutting Tools, Files and Abrasives. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on cutting tools, files, and abrasives is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to enable students to identify and explain the proper use and care of various knives, saws, snips, chisels, and abrasives. The module may contain some or all of the…

  1. Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study.

    PubMed

    Tan, Melissa H X; Hill, Robert G; Anderson, Paul

    2015-01-01

    Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38-80 μm) versus the conventional alumina abrasive (29 μm) in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p < 0.05) despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine. PMID:26697067

  2. Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study

    PubMed Central

    Tan, Melissa H. X.; Hill, Robert G.; Anderson, Paul

    2015-01-01

    Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38–80 μm) versus the conventional alumina abrasive (29 μm) in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p < 0.05) despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine. PMID:26697067

  3. Influence of air abrasion tips and operation modes on enamel-cutting characteristics

    PubMed Central

    Peruchi, Cláudia; Santos-Pinto, Ary; Dias, Tereza Cristina; Oliveira, Ana Carolina Mascarenhas; Santos-Pinto, Lourdes

    2013-01-01

    Objective: To assess the influence of air abrasion tips and system operation modes on enamel cutting. Methods: Forty bovine teeth were abraded with the air abrasion system Mach 4.1 for 10 and 15 seconds, employing conventional and sonic tips of 0.45-mm inner diameter and a 90° angle, and 27.5-μm aluminum oxide at 5.51 bar air pressure in continuous and pulsed modes. The width and depth of the resulting cuts were measured in SEM. Results: The multivariate analysis of variances revealed that, compared to the sonic tip, the conventional tip produced shallower cuts independent of the operation mode and the application period. Conclusions: The cutting patterns observed in this study suggest that the pulsed mode produced deeper cuts when both the conventional and sonic tips were used, and that the sonic tip cut more dental tissue than the conventional one. PMID:23408157

  4. Quantitative evaluation of the cutting quality and abrasive resistance of scalers.

    PubMed

    Kaya, H; Fujimura, T; Kimura, S

    1995-01-01

    An automatic scaling apparatus that simulated the scaling process of hand instrumentation was developed to quantitatively analyze the cutting quality and abrasive resistance of scalers. We first tested 4 synthetic resins as the abraded material. Of the 4 synthetic resins tested, polycarbonate resin proved most similar to dentin. The effects of lateral scaling forces (700, 500, and 300 dyne) and scaler angles (70 degrees to 95 degrees) on the cutting quality and abrasive resistance of scalers were evaluated quantitatively by the amount of the abraded material worn away in 1,000 strokes. Comparison of the 3 scaling forces showed a greater amount of abrasion at higher force than that at lower force. This suggests that the decrease in the amount due to abrasion could be compensated by increasing the lateral scaling force. Regarding the scaler angle, results indicated that the amount of material removed increased with an increase of the scaler angle up to 70 degrees, but then rapidly decreased at an angle of 90 degrees or more. The most effective scaling angle was 87 degrees, and this was not affected by scaling force. These results suggest that a greater amount of removal could be obtained at a scaling angle of 87 degrees and a scaling force of 700 dyne. The present findings suggested the automatic scaling apparatus could be a useful tool for quantitatively evaluating the cutting quality and abrasive resistance of scalers.

  5. Rock Cutting Depth Model Based on Kinetic Energy of Abrasive Waterjet

    NASA Astrophysics Data System (ADS)

    Oh, Tae-Min; Cho, Gye-Chun

    2016-03-01

    Abrasive waterjets are widely used in the fields of civil and mechanical engineering for cutting a great variety of hard materials including rocks, metals, and other materials. Cutting depth is an important index to estimate operating time and cost, but it is very difficult to predict because there are a number of influential variables (e.g., energy, geometry, material, and nozzle system parameters). In this study, the cutting depth is correlated to the maximum kinetic energy expressed in terms of energy (i.e., water pressure, water flow rate, abrasive feed rate, and traverse speed), geometry (i.e., standoff distance), material (i.e., α and β), and nozzle system parameters (i.e., nozzle size, shape, and jet diffusion level). The maximum kinetic energy cutting depth model is verified with experimental test data that are obtained using one type of hard granite specimen for various parameters. The results show a unique curve for a specific rock type in a power function between cutting depth and maximum kinetic energy. The cutting depth model developed here can be very useful for estimating the process time when cutting rock using an abrasive waterjet.

  6. An in-vitro investigation of the effects of variable operating parameters on alumina air-abrasion cutting characteristics.

    PubMed

    Paolinelis, George; Banerjee, Avijit; Watson, Timothy F

    2009-01-01

    Air-abrasion is a tooth preparation technology developed in the 1940s that is currently gaining popularity due to its compatibility with adhesive restorations. Variables, including propellant pressure, powder flow rate, nozzle angle and distance to the tooth surface abrasion time, can affect the cutting rate of the air-abrasion unit. A static setup and a more clinically realistic dynamic experimental setup have been used to assess the effect of these parameters of the cutting rate on an enamel analogue. By keeping each parameter fixed, its effect on the cutting rate was examined. The results showed that increasing the propellant pressure (20-100 PSI) caused an almost linear increase in the cutting rate in both setups. Increasing the powder flow rate (0.5 - 3 g/minute) concurrently increased the powder flow and caused an increase in the cutting rate but with a plateau differing for the different propellant pressures. The nozzle angles producing the highest cutting rates were 60 degrees and 75 degrees for static and dynamic cutting, respectively, with smaller and larger angles producing lower rates. Increasing abrasion time in static cutting and the nozzle advancement rate in dynamic cutting both caused an increase in the cutting rate. These findings are relevant for both clinicians, who might wish to alter the cutting rate of their instrument, and researchers, who should always control the numerous parameters in studies involving air-abrasion in order to control the variables, which can influence the end effect of air-abrasion.

  7. High pressure water jet mining machine

    DOEpatents

    Barker, Clark R.

    1981-05-05

    A high pressure water jet mining machine for the longwall mining of coal is described. The machine is generally in the shape of a plowshare and is advanced in the direction in which the coal is cut. The machine has mounted thereon a plurality of nozzle modules each containing a high pressure water jet nozzle disposed to oscillate in a particular plane. The nozzle modules are oriented to cut in vertical and horizontal planes on the leading edge of the machine and the coal so cut is cleaved off by the wedge-shaped body.

  8. In vitro effect of air-abrasion operating parameters on dynamic cutting characteristics of alumina and bio-active glass powders.

    PubMed

    Milly, H; Austin, R S; Thompson, I; Banerjee, A

    2014-01-01

    Minimally invasive dentistry advocates the maintenance of all repairable tooth structures during operative caries management in combination with remineralization strategies. This study evaluated the effect of air-abrasion operating parameters on its cutting efficiency/pattern using bio-active glass (BAG) powder and alumina powder as a control in order to develop its use as a minimally invasive operative technique. The cutting efficiency/pattern assessment on an enamel analogue, Macor, was preceded by studying the powder flow rate (PFR) of two different commercial intraoral air-abrasion units with differing powder-air admix systems. The parameters tested included air pressure, powder flow rate, nozzle-substrate distance, nozzle angle, shrouding the air stream with a curtain of water, and the chemistry of abrasive powder. The abraded troughs were scanned and analyzed using confocal white light profilometry and MountainsMap surface analysis software. Data were analyzed statistically using one-way and repeated-measures analysis of variance tests (p=0.05). The air-abrasion unit using a vibration mechanism to admix the abrasive powder with the air stream exhibited a constant PFR regardless of the set air pressure. Significant differences in cutting efficiency were observed according to the tested parameters (p<0.05). Alumina powder removed significantly more material than did BAG powder. Using low air pressure and suitable consideration of the effect of air-abrasion parameters on cutting efficiency/patterns can improve the ultraconservative cutting characteristics of BAG air-abrasion, thereby allowing an introduction of this technology for the controlled cleaning/removal of enamel, where it is indicated clinically.

  9. Reducing Coal Dust With Water Jets

    NASA Technical Reports Server (NTRS)

    Gangal, M. D.; Lewis, E. V.

    1985-01-01

    Jets also cool and clean cutting equipment. Modular pick-and-bucket miner suffers from disadvantage: Creates large quantities of potentially explosive coal dust. Dust clogs drive chain and other parts and must be removed by hand. Picks and bucket lips become overheated by friction and be resharpened or replaced frequently. Addition of oscillating and rotating water jets to pick-and-bucket machine keeps down dust, cools cutting edges, and flushes machine. Rotating jets wash dust away from drive chain. Oscillating jets cool cutting surfaces. Both types of jet wet airborne coal dust; it precipitates.

  10. Thickness-Independent Ultrasonic Imaging Applied to Abrasive Cut-Off Wheels: An Advanced Aerospace Materials Characterization Method for the Abrasives Industry. A NASA Lewis Research Center Technology Transfer Case History

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Farmer, Donald A.

    1998-01-01

    Abrasive cut-off wheels are at times unintentionally manufactured with nonuniformity that is difficult to identify and sufficiently characterize without time-consuming, destructive examination. One particular nonuniformity is a density variation condition occurring around the wheel circumference or along the radius, or both. This density variation, depending on its severity, can cause wheel warpage and wheel vibration resulting in unacceptable performance and perhaps premature failure of the wheel. Conventional nondestructive evaluation methods such as ultrasonic c-scan imaging and film radiography are inaccurate in their attempts at characterizing the density variation because a superimposing thickness variation exists as well in the wheel. In this article, the single transducer thickness-independent ultrasonic imaging method, developed specifically to allow more accurate characterization of aerospace components, is shown to precisely characterize the extent of the density variation in a cut-off wheel having a superimposing thickness variation. The method thereby has potential as an effective quality control tool in the abrasives industry for the wheel manufacturer.

  11. Wear characterization of abrasive waterjet nozzles and nozzle materials

    NASA Astrophysics Data System (ADS)

    Nanduri, Madhusarathi

    Parameters that influence nozzle wear in the abrasive water jet (AWJ) environment were identified and classified into nozzle geometric, AWJ system, and nozzle material categories. Regular and accelerated wear test procedures were developed to study nozzle wear under actual and simulated conditions, respectively. Long term tests, using garnet abrasive, were conducted to validate the accelerated test procedure. In addition to exit diameter growth, two new measures of wear, nozzle weight loss and nozzle bore profiles were shown to be invaluable in characterizing and explaining the phenomena of nozzle wear. By conducting nozzle wear tests, the effects of nozzle geometric, and AWJ system parameters on nozzle wear were systematically investigated. An empirical model was developed for nozzle weight loss rate. To understand the response of nozzle materials under varying AWJ system conditions, erosion tests were conducted on samples of typical nozzle materials. The effect of factors such as jet impingement angle, abrasive type, abrasive size, abrasive flow rate, water pressure, traverse speed, and target material was evaluated. Scanning electron microscopy was performed on eroded samples as well as worn nozzles to understand the wear mechanisms. The dominant wear mechanism observed was grain pullout. Erosion models were reviewed and along the lines of classical erosion theories a semi-empirical model, suitable for erosion of nozzle materials under AWJ impact, was developed. The erosion data correlated very well with the developed model. Finally, the cutting efficiency of AWJ nozzles was investigated in conjunction with nozzle wear. The cutting efficiency of a nozzle deteriorates as it wears. There is a direct correlation between nozzle wear and cutting efficiency. The operating conditions that produce the most efficient jets also cause the most wear in the nozzle.

  12. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  13. Spray Deflector For Water-Jet Machining

    NASA Technical Reports Server (NTRS)

    Cawthon, Michael A.

    1989-01-01

    Disk on water-jet-machining nozzle protects nozzle and parts behind it from erosion by deflected spray. Consists of stainless-steel backing with neoprene facing deflecting spray so it does not reach nut or other vital parts of water-jet apparatus.

  14. Study and application of a high-pressure water jet multi-functional flow test system.

    PubMed

    Shi, Huaizhong; Li, Gensheng; Huang, Zhongwei; Li, Jingbin; Zhang, Yi

    2015-12-01

    As the exploration and development of oil and gas focus more and more on deeper formation, hydraulic issues such as high-pressure water jet rock breaking, wellbore multiphase flow law, cuttings carrying efficiency, and hydraulic fracturing technique during the drilling and completion process have become the key points. To accomplish related researches, a high-pressure water jet multi-functional flow test system was designed. The following novel researches are carried out: study of high-pressure water jet characteristics under confining pressure, wellbore multiphase flow regime, hydraulic pressure properties of down hole tools during jet fracturing and pulsed cavitation jet drilling, and deflector's friction in radial jet drilling. The validity and feasibility of the experimental results provided by the system with various test modules have proved its importance in the research of the high-pressure water jet and well completion technology. PMID:26724077

  15. Study and application of a high-pressure water jet multi-functional flow test system.

    PubMed

    Shi, Huaizhong; Li, Gensheng; Huang, Zhongwei; Li, Jingbin; Zhang, Yi

    2015-12-01

    As the exploration and development of oil and gas focus more and more on deeper formation, hydraulic issues such as high-pressure water jet rock breaking, wellbore multiphase flow law, cuttings carrying efficiency, and hydraulic fracturing technique during the drilling and completion process have become the key points. To accomplish related researches, a high-pressure water jet multi-functional flow test system was designed. The following novel researches are carried out: study of high-pressure water jet characteristics under confining pressure, wellbore multiphase flow regime, hydraulic pressure properties of down hole tools during jet fracturing and pulsed cavitation jet drilling, and deflector's friction in radial jet drilling. The validity and feasibility of the experimental results provided by the system with various test modules have proved its importance in the research of the high-pressure water jet and well completion technology.

  16. Study and application of a high-pressure water jet multi-functional flow test system

    NASA Astrophysics Data System (ADS)

    Shi, Huaizhong; Li, Gensheng; Huang, Zhongwei; Li, Jingbin; Zhang, Yi

    2015-12-01

    As the exploration and development of oil and gas focus more and more on deeper formation, hydraulic issues such as high-pressure water jet rock breaking, wellbore multiphase flow law, cuttings carrying efficiency, and hydraulic fracturing technique during the drilling and completion process have become the key points. To accomplish related researches, a high-pressure water jet multi-functional flow test system was designed. The following novel researches are carried out: study of high-pressure water jet characteristics under confining pressure, wellbore multiphase flow regime, hydraulic pressure properties of down hole tools during jet fracturing and pulsed cavitation jet drilling, and deflector's friction in radial jet drilling. The validity and feasibility of the experimental results provided by the system with various test modules have proved its importance in the research of the high-pressure water jet and well completion technology.

  17. Experiment and simulation study of laser dicing silicon with water-jet

    NASA Astrophysics Data System (ADS)

    Bao, Jiading; Long, Yuhong; Tong, Youqun; Yang, Xiaoqing; Zhang, Bin; Zhou, Zupeng

    2016-11-01

    Water-jet laser processing is an internationally advanced technique, which combines the advantages of laser processing with water jet cutting. In the study, the experiment of water-jet laser dicing are conducted with ns pulsed laser of 1064 nm irradiating, and Smooth Particle Hydrodynamic (SPH) technique by AUTODYN software was modeled to research the fluid dynamics of water and melt when water jet impacting molten material. The silicon surface morphology of the irradiated spots has an appearance as one can see in porous formation. The surface morphology exhibits a large number of cavities which indicates as bubble nucleation sites. The observed surface morphology shows that the explosive melt expulsion could be a dominant process for the laser ablating silicon in liquids with nanosecond pulse laser of 1064 nm irradiating. Self-focusing phenomenon was found and its causes are analyzed. Smooth Particle Hydrodynamic (SPH) modeling technique was employed to understand the effect of water and water-jet on debris removal during water-jet laser machining.

  18. Water jet assisted tunnel boring

    SciTech Connect

    Ozdemir, L.

    1984-06-21

    Mechanical tunnel boring has experienced significant growth over the last two decades. Improved machine design and performance coupled with a better understanding of factors affecting boreability have contributed to a dramatic increase in the number of machine bored tunnels. Today, tunnel boring machines (TBMs) are finding widespread application in various sectors of underground construction industry, both civil and mining. Most of the hard rock formations considered unsuited to mechanical boring only a few years ago are now excavated with TBMs with favorable economics compared to conventional drill and blast methods. Despite the advancements accomplished, TBMs need further improvements in design and operation to exend their capabilities and to reduce excavation costs, particularly in hard, abrasive rocks. The design of TBMs has presently reached a state where no additional major breakthroughs are anticipated in the near future. The cutter material appears to be the major obstacle to achieving further performance improvements. The amount of load which the cutters can sustain with acceptable levels of wear is the limiting factor determining the magnitude of the power that can be placed on a TBM. In fact, most present day TBMs can generate more thrust and torque than the individual cutters are capable of supporting.

  19. Selection of the most influential factors on the water-jet assisted underwater laser process by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Nikolić, Vlastimir; Petković, Dalibor; Lazov, Lyubomir; Milovančević, Miloš

    2016-07-01

    Water-jet assisted underwater laser cutting has shown some advantages as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. It is important to determine which parameters are the most important for the process. In this investigation was analyzed the water-jet assisted underwater laser cutting parameters forecasting based on the different parameters. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for water-jet assisted underwater laser cutting parameters forecasting. Three inputs are considered: laser power, cutting speed and water-jet speed. The ANFIS process for variable selection was also implemented in order to detect the predominant factors affecting the forecasting of the water-jet assisted underwater laser cutting parameters. According to the results the combination of laser power cutting speed forms the most influential combination foe the prediction of water-jet assisted underwater laser cutting parameters. The best prediction was observed for the bottom kerf-width (R2 = 0.9653). The worst prediction was observed for dross area per unit length (R2 = 0.6804). According to the results, a greater improvement in estimation accuracy can be achieved by removing the unnecessary parameter.

  20. Ultra-high pressure water jetting for coating removal and surface preparation

    NASA Technical Reports Server (NTRS)

    Johnson, Spencer T.

    1995-01-01

    This paper shall examine the basics of water technology with particular attention paid to systems currently in use and some select new applications. By providing an overview of commercially available water jet systems in the context of recent case histories, potential users may evaluate the process for future applications. With the on going introduction of regulations prohibiting the use of chemical paint strippers, manual scrapping and dry abrasive media blasting, the need for an environmentally compliant coating removal process has been mandated. Water jet cleaning has been a traditional part of many industrial processed for year, although it has only been in the last few years that reliable pumping equipment capable of ultra-high pressure operation have become available. With the advent of water jet pumping equipment capable of sustaining pressures in excess of 36,000 psi. there has been shift away from lower pressure, high water volume systems. One of the major factors in driving industry to seek higher pressures is the ability to offer higher productivity rates while lowering the quantity of water used and subsequently reprocessed. Among benefits of the trend toward higher pressure/lower volume systems is the corresponding reduction in water jet reaction forces making hand held water jetting practical and safe. Other unique applications made possible by these new generation pumping systems include the use of alternative fluids including liquid ammonia for specialized and hazardous material removal applications. A review of the equipment used and the required modifications will be presented along with the conclusions reached reached during this test program.

  1. Mechanical cutting of irradiated reactor internal components

    SciTech Connect

    Anderson, Michael G.

    2008-01-15

    Mechanical cutting methods to volume reduce and package reactor internal components are now a viable solution for stakeholders challenged with the retirement of first generation nuclear facilities. The recent completion of the removal of the Reactor Vessel Internals (RVI) from within the Sacramento Municipal Utility District's (SMUD) Rancho Seco Nuclear Power Plant demonstrates that unlike previous methods, inclusive of plasma arc and abrasive water-jet cutting, mechanical cutting minimizes exposure to workers, costly water cleanup, and excessive secondary waste generation. Reactor internal components were segmented, packaged, and removed from the reactor building for shipment or storage, allowing the reactor cavity to be drained and follow-on reactor segmentation activities to proceed in the dry state. Area exposure rates at the work positions during the segmentation process were generally 1 mR per hr. Radiological exposure documented for the underwater segmentation processes totaled 13 person rem. The reactor internals weighing 343,000 pounds were segmented into over 200 pieces for maximum shipping package efficiency and produced 5,600 lb of stainless steel chips and shavings which were packaged in void spaces of existing disposal containers, therefore creating no additional disposal volume. Because no secondary waste was driven into suspension in the reactor cavity water, the water was free released after one pass through a charcoal bed and ion exchange filter system. Mechanical cutting techniques are capable of underwater segmentation of highly radioactive components on a large scale. This method minimized radiological exposure and costly water cleanup while creating no secondary waste.

  2. Water Jets from Bottles, Buckets, Barrels, and Vases with Holes

    ERIC Educational Resources Information Center

    Lopac, Vjera

    2015-01-01

    Observation of the water jets flowing from three equidistant holes on the side of a vertical cylindrical bottle is an interesting and widely used didactical experiment illustrating the laws of fluids in motion. In this paper we analyze theoretically and numerically the ranges of the stationary water jets flowing from various rotationally symmetric…

  3. Circular and Elliptic Submerged Impinging Water Jets

    NASA Astrophysics Data System (ADS)

    Claudey, Eric; Benedicto, Olivier; Ravier, Emmanuel; Gutmark, Ephraim

    1999-11-01

    Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

  4. The dental water jet: a product ahead of its time.

    PubMed

    Ciancio, Sebastian G

    2009-03-01

    The dental water jet was invented by Dr. Gerald Moyer, a dentist, and John Mattingly, an engineer, in Ft. Collins, Colorado, in the late 1950s. The dental water jet, also known as an oral irrigator, was introduced to the dental profession in Texas during the 1962 Dallas Dental Convention. Numerous studies measuring the irrigator's efficacy in different cohorts have been published in peer-reviewed journals. The results of those studies are discussed in this article. The bulk of research has been conducted on one product (Waterpik dental water jet, Water Pik, Inc, Fort Collins, CO). This article is designed to provide dental professionals with the evidence essential to making an informed decision on the oral health benefits and expected outcomes of the dental water jet. PMID:19385350

  5. The dental water jet: a product ahead of its time.

    PubMed

    Ciancio, Sebastian G

    2009-03-01

    The dental water jet was invented by Dr. Gerald Moyer, a dentist, and John Mattingly, an engineer, in Ft. Collins, Colorado, in the late 1950s. The dental water jet, also known as an oral irrigator, was introduced to the dental profession in Texas during the 1962 Dallas Dental Convention. Numerous studies measuring the irrigator's efficacy in different cohorts have been published in peer-reviewed journals. The results of those studies are discussed in this article. The bulk of research has been conducted on one product (Waterpik dental water jet, Water Pik, Inc, Fort Collins, CO). This article is designed to provide dental professionals with the evidence essential to making an informed decision on the oral health benefits and expected outcomes of the dental water jet.

  6. Use of water jet instruments in gastrointestinal endoscopy

    PubMed Central

    Nakano, Toru; Sato, Chiaki; Sakurai, Tadashi; Kamei, Takashi; Nakagawa, Atsuhiro; Ohuchi, Noriaki

    2016-01-01

    In recent years, water jet instruments have been used in the field of gastrointestinal endoscopy, mainly in two clinical situations: Investigation and treatment under endoscopic view. Injecting water jet into the gastrointestinal lumen is helpful for maintaining a clear endoscopic view, washing away blood or mucous in the lumen or on the surface of the tip of the endoscope. This contributes to reducing time and discomfort of examination. Water jet technology is an alternative method for dissecting soft tissue; this method does not harm the small vessels or cause mechanical or thermal damage. However, its use in clinical settings has been limited to the transmucosal injection of water into the submucosal layer that elevates the mucosa to prepare for endoscopic mucosal resection or endoscopic submucosal dissection, instead of tissue dissection, which may occur because of the continuous water jet. A preclinical study has been conducted using a pulsed water jet system as an alternative method for submucosal dissection by reducing intraoperative water consumption and maintenance of dissection capability. This review introduces recent studies pertaining to using a water jet in gastrointestinal endoscopy and discusses future prospects. PMID:26862362

  7. Utilization of ultrasound to enhance high-speed water jet effects.

    PubMed

    Foldyna, Josef; Sitek, Libor; Svehla, Branislav; Svehla, Stefan

    2004-05-01

    Continuous high-speed water jets are presently used in many industrial applications such as cutting of various materials, cleaning and removal of surface layers. However, there is still a need for further research to enhance the performance of pure water jets. An obvious method is to generate water jets at ultra-high pressures (currently up to 700 MPa). An alternate approach is to eliminate the need for such high pressures by pulsing of the jet. This follows from the fact that the impact pressure on a target generated by a slug of water is considerably higher than the stagnation pressure of a corresponding continuous jet. Ultrasonically forced modulation of a continuous stream of water represents the most promising method of pulsed jet generation because of its simplicity and practicality. A pulsed jet is generated by modulating a continuous stream of water by ultrasonic waves. A velocity transformer connected to a piezoelectric transducer is located axially inside a nozzle to induce longitudinal pulsations in the water. An extensive laboratory research program is in progress to understand the basic principles of the process and to optimize the nozzle design for several applications. The results reported in this paper show that the performance of such a pulsed jet is far superior to that of a continuous jet operating at the same parameters. Experimental results obtained with the ultrasonic vibration of a tip situated inside the nozzle indicate that using this technique one can achieve performance of the jet even order of magnitude higher in comparison to continuous jet at the same hydraulic parameters. Performance of ultrasonically modulated jets in cutting of various materials was tested in laboratory conditions. In this paper, results of measurement of dynamic pressure in the nozzle and force effects of modulated jets are presented together with results obtained in cutting of various materials using ultrasonically modulated water jets. The results are compared

  8. A review of engineering control technology for exposures generated during abrasive blasting operations.

    PubMed

    Flynn, Michael R; Susi, Pam

    2004-10-01

    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 exposures to operators and surrounding personnel. Recently, several alternative abrasives have emerged as potential substitutes for sand, but they seem to be underused Some of these abrasives may pose additional metal exposure hazards. In addition, several new and improved technologies offer promise for reducing or eliminating exposures; these include wet abrasive blasting, high-pressure water jetting, vacuum blasting, and automated/robotic systems. More research, particularly field studies, is needed to evaluate control interventions in this important and hazardous operation.

  9. Portable cutting apparatus

    DOEpatents

    Gilmore, R.F.

    1984-07-17

    A remotely operable, portable cutting apparatus detachably secured to the workpiece by laterally spaced clamp assemblies engagable with the workpiece on opposite sides of the intended line of cut. A reciprocal cutter head is mounted between the clamp assemblies and is provided with a traveling abrasive cutting wire adapted to sever the workpiece normal to the longitudinal axis thereof. Dust and debris are withdrawn from the cutting area by a vacuum force through a nozzle mounted on the cutting head.

  10. All-Water-Jet Coal Excavator

    NASA Technical Reports Server (NTRS)

    Gangal, M. D.

    1985-01-01

    Version of jaw miner operates without mechanical cutting and crushing. Forward-pointing jets of water dislodge and break up coal. Rearward-pointing jets further break up coal and force particles into slurry chamber. Oscillatingjet mechanism itself stays within "jaw" structure and protected from wear and tear associated with coal handling. All-jet machine generates even less dust than anger, therefore poses lesser explosion or health hazard.

  11. [The application of air abrasion in dentistry].

    PubMed

    Mandinić, Zoran; Vulićević, Zoran R; Beloica, Milos; Radović, Ivana; Mandić, Jelena; Carević, Momir; Tekić, Jasmina

    2014-01-01

    One of the main objectives of contemporary dentistry is to preserve healthy tooth structure by applying techniques of noninvasive treatment. Air abrasion is a minimally invasive nonmechanical technique of tooth preparation that uses kinetic energy to remove carious tooth structure. A powerful narrow stream of moving aluminum-oxide particles hit the tooth surface and they abrade it without heat, vibration or noise. Variables that affect speed of cutting include air pressure, particle size, powder flow, tip's size, angle and distance from the tooth. It has been proposed that air abrasion can be used to diagnose early occlusal-surface lesions and treat them with minimal tooth preparation using magnifier. Reported advantages of air abrasion include reduced noise, vibration and sensitivity. Air abrasion cavity preparations have more rounded internal contours than those prepared with straight burs. This may increase the longevity of placed restorations because it reduces the incidence of fractures and a consequence of decreased internal stresses. However, air abrasion cannot be used for all patients, i.e. in cases involving severe dust allergy, asthma, chronic obstructive lung disease, recent extraction or other oral surgery, open wounds, advanced periodontal disease, recent placement of orthodontic appliances and oral abrasions, or subgingival caries removal. Many of these conditions increase the risk of air embolism in the oral soft tissues. Dust control is a challenge, and it necessitates the use of rubber dam, high-volume evacuation, protective masks and safety eyewear for both the patient and the therapist.

  12. Air abrasion: an old technology reborn.

    PubMed

    Berry, E A; Eakle, W S; Summitt, J B

    1999-08-01

    Recently, air abrasion has experienced a rebirth in restorative dentistry. Originally developed in the late 1940s, the principle of air abrasion is the imparting of kinetic energy to tiny aluminum oxide particles that are projected by a stream of compressed air or gas and expelled from a small nozzle. The force generated by the relatively hard particles striking a relatively hard surface is sufficient to cut into that surface. In the last decade, more than a dozen models of air abrasion units have been introduced into the marketplace and more are on the way. Manufacturers have developed air abrasion instruments that offer a broad range of features, from small table-top units to self-contained systems with compressors, vacuums, and curing lights. The costs range dramatically--from $1,000 to $20,000 or more--depending on the complexity of the features and attachments. Manufacturers make a variety of claims to support the value of this technology to the practicing dentist. A term often used to describe one of the benefits of air abrasion is microdentistry. The claim is that smaller, less invasive tooth preparations may be accomplished using air abrasion than with a traditional bur and air turbine. This may be true in some instances, but it would certainly depend on the operator's experience and ability to visually discern fine detail. Other claims about air abrasion are that it can be used to cut into tooth structure without local anesthesia and that it should be used on all stained grooves or fissures to determine if incipient carious lesions are present. Despite the limited number of clinical studies, the popularity of air abrasion continues to grow. To gain additional insight about these claims and to see what might be on the horizon for this technology, I spoke with three highly respected educators who are recognized for their expertise in air abrasion. What they said should give the reader a better understanding of how air abrasion might augment restorative

  13. Behavior of Water Jet Accompanied with Air Suction

    NASA Astrophysics Data System (ADS)

    Kawakami, Hironobu; Ishido, Tsutomu; Ihara, Akio

    In order to atomize a liquid, the authors have investigated the behavior of air-water jets. In a series of experiments, we have discovered a strange phenomenon that the water jet accompanied with air suction from the free surface has made a periodic radial splash of water drop. The purpose of the present paper is to clear out the origin of this phenomenon and the behavior of water jet accompanied with air suction. The behavior of water jet has been photographed by a digital camera aided with a flashlight and high-speed video camera. Those experiments enable us to find the origin of a periodic radial splash due to a formation of single air bubble at the flow separation region inside the nozzle and due to explosive expansion of the bubble after injected in the free space. In order to analyze the radial splash of water, we have conducted the equation of spherical liquid membrane. The numerical results obtained have been compared with the experimental results and good agreement has been obtained in radial expansion velocity.

  14. Water Jets from Bottles, Buckets, Barrels, and Vases with Holes

    NASA Astrophysics Data System (ADS)

    Lopac, Vjera

    2015-03-01

    Observation of the water jets flowing from three equidistant holes on the side of a vertical cylindrical bottle is an interesting and widely used didactical experiment illustrating the laws of fluids in motion. In this paper we analyze theoretically and numerically the ranges of the stationary water jets flowing from various rotationally symmetric vessels with holes, and their dependence on the height of the holes above the bottom, on thickness of the block supporting the vessel, and on different shapes of the vessel profile. This investigation was motivated by controversial descriptions and illustrations repeatedly found in physics textbooks and by the fact that previously in the physics teaching literature only the cylindrical vessel was treated.

  15. Thermal Investigation of Interaction between High-power CW-laser Radiation and a Water-jet

    NASA Astrophysics Data System (ADS)

    Brecher, Christian; Janssen, Henning; Eckert, Markus; Schmidt, Florian

    The technology of a water guided laser beam has been industrially established for micro machining. Pulsed laser radiation is guided via a water jet (diameter: 25-250 μm) using total internal reflection. Due to the cylindrical jet shape the depth of field increases to above 50 mm, enabling parallel kerfs compared to conventional laser systems. However higher material thicknesses and macro geometries cannot be machined economically viable due to low average laser powers. Fraunhofer IPT has successfully combined a high-power continuous-wave (CW) fiber laser (6 kW) and water jet technology. The main challenge of guiding high-power laser radiation in water is the energy transferred to the jet by absorption, decreasing its stability. A model of laser water interaction in the water jet has been developed and validated experimentally. Based on the results an upscaling of system technology to 30 kW is discussed, enabling a high potential in cutting challenging materials at high qualities and high speeds.

  16. Method for forming an abrasive surface on a tool

    DOEpatents

    Seals, Roland D.; White, Rickey L.; Swindeman, Catherine J.; Kahl, W. Keith

    1999-01-01

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

  17. Methodology of evaluation of abrasive tool wear with the use of laser scanning microscopy.

    PubMed

    Lipiński, Dariusz; Kacalak, Wojciech; Tomkowski, Robert

    2014-01-01

    Grinding is one of the basic precise material removal methods. Abrasive and shape wear, as well as smearing of the tools' active surface handicap the processing results. The loss of cutting capacity in abrasive tools or alteration of their shape influences the surface quality and precision of the workpiece dimensions and its shape. Evaluation of the abrasive tool surface is the basic criterion of forecasting the tools' durability and the process results. The applied method of laser scanning made determination of the surface coordinates and subsequently of its geometric features with micrometric accuracy possible. Using the information on the abrasive tool surface geometric structure, a methodology of evaluation of the level of changes in geometric features of the tool during the grinding process was developed. Criteria for evaluation of the level of abrasive grains attritious wear, the degree of smearing of the abrasive tool surface and evaluation of the cutting capability of the abrasive tools were determined. The developed method allowed for evaluation of the level of abrasive tools' wear, and subsequently formed foundations for assessment of the influence of the grinding parameters on the durability of abrasive tools, evaluation of the influence of the parameters of the process of shaping the abrasive tools' active surfaces on their geometric characteristics and evaluation of the level of correlation between the monitored process parameters and the degree of the abrasive tools' wear.

  18. Universal scaling relations for pebble abrasion

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  19. Enhancement Of Water-Jet Stripping Of Foam

    NASA Technical Reports Server (NTRS)

    Cosby, Steven A.; Shockney, Charles H.; Bates, Keith E.; Shalala, John P.; Daniels, Larry S.

    1995-01-01

    Improved robotic high-pressure-water-jet system strips foam insulation from parts without removing adjacent coating materials like paints, primers, and sealants. Even injects water into crevices and blind holes to clean out foam, without harming adjacent areas. Eliminates both cost of full stripping and recoating and problem of disposing of toxic solutions used in preparation for coating. Developed for postflight refurbishing of aft skirts of booster rockets. System includes six-axis robot provided with special end effector and specially written control software, called Aftfoam. Adaptable to cleaning and stripping in other industrial settings.

  20. Valve for abrasive material

    DOEpatents

    Gardner, Harold S.

    1982-01-01

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

  1. Abrasive Wear Study of NiCrFeSiB Flame Sprayed Coating

    NASA Astrophysics Data System (ADS)

    Sharma, Satpal

    2013-10-01

    In the present study, abrasive wear behavior of NiCrFeSiB alloy coating on carbon steel was investigated. The NiCrFeSiB coating powder was deposited by flame spraying process. The microstructure, porosity and hardness of the coatings were evaluated. Elemental mapping was carried out in order to study the distribution of various elements in the coating. The abrasive wear behavior of these coatings was investigated under three normal loads (5, 10 and 15 N) and two abrasive grit sizes (120 and 320 grit). The abrasive wear rate was found to increase with the increase of load and abrasive size. The abrasive wear resistance of coating was found to be 2-3 times as compared to the substrate. Analysis of the scanning electron microscope images revealed cutting and plowing as the material removal mechanisms in these coatings under abrasive wear conditions used in this investigation.

  2. Acceptance test procedure for High Pressure Water Jet System

    SciTech Connect

    Crystal, J.B.

    1995-05-30

    The overall objective of the acceptance test is to demonstrate a combined system. This includes associated tools and equipment necessary to perform cleaning in the 105 K East Basin (KE) for achieving optimum reduction in the level of contamination/dose rate on canisters prior to removal from the KE Basin and subsequent packaging for disposal. Acceptance tests shall include necessary hardware to achieve acceptance of the cleaning phase of canisters. This acceptance test procedure will define the acceptance testing criteria of the high pressure water jet cleaning fixture. The focus of this procedure will be to provide guidelines and instructions to control, evaluate and document the acceptance testing for cleaning effectiveness and method(s) of removing the contaminated surface layer from the canister presently identified in KE Basin. Additionally, the desired result of the acceptance test will be to deliver to K Basins a thoroughly tested and proven system for underwater decontamination and dose reduction. This report discusses the acceptance test procedure for the High Pressure Water Jet.

  3. High Energy Cutting and Stripping Utilizing Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    Hume, Howard; Noah, Donald E.; Hayes, Paul W.

    2005-01-01

    The Aerospace Industry has endeavored for decades to develop hybrid materials that withstand the rigors of mechanized flight both within our atmosphere and beyond. The development of these high performance materials has led to the need for environmentally friendly technologies for material re-work and removal. The NitroJet(TM) is a fluid jet technology that represents an evolution of the widely used, large-scale water jet fluid jet technology. It involves the amalgamation of fluid jet technology and cryogenics technology to create a new capability that is applicable where water jet or abrasive jet (water jet plus entrained abrasive) are not suitable or acceptable because of technical constraints such as process or materials compatibility, environmental concerns and aesthetic or legal requirements. The NitroJet(TM) uses ultra high-pressure nitrogen to cut materials, strip numerous types of coatings such as paint or powder coating, clean surfaces and profile metals. Liquid nitrogen (LN2) is used as the feed stream and is pressurized in two stages. The first stage pressurizes sub cooled LN2 to an intermediate pressure of between 15,000 and 20,000 psi at which point the temperature of the LN2 is about -250 F. The discharge from this stage is then introduced as feed to a dual intensifier system, which boosts the pressure from 15,000 - 20,000 psi up to the maximum operating pressure of 55,000 psi. A temperature of about -220 F is achieved at which point the nitrogen is supercritical. In this condition the nitrogen cuts, strips and abrades much like ultra high-pressure water would but without any residual liquid to collect, remove or be contaminated. Once the nitrogen has performed its function it harmlessly flashes back into the atmosphere as pure nitrogen gas. The system uses heat exchangers to control and modify the temperature of the various intake and discharge nitrogen streams. Since the system is hydraulically operated, discharge pressures can be easily varied over

  4. Wind abrasion on Mars

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald

    1991-01-01

    Aeolian activity was predicted for Mars from earth based observations of changing surface patterns that were interpreted as dust storms. Mariner 9 images showed conclusive evidence for aeolian processes in the form of active dust storms and various aeolian landforms including dunes and yardangs. Windspeeds to initiate particle movement are an order of magnitude higher on Mars than on Earth because of the low atmospheric density on Mars. In order to determine rates of abrasion by wind blown particles, knowledge of three factors is required: (1) particle parameters such as numbers and velocities of windblown grains as functions of windspeeds at various heights above the surface; (2) the susceptibility to abrasion of various rocks and minerals; and (3) wind frequencies and speeds. For estimates appropriate to Mars, data for the first two parameters can be determined through lab and wind tunnel tests; data for the last two factors are available directly from the Viking Lander meteorology experiments for the two landing sites.

  5. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M.

    1984-10-23

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

  6. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

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

  7. Method and apparatus for jet-assisted drilling or cutting

    DOEpatents

    Summers, David Archibold; Woelk, Klaus Hubert; Oglesby, Kenneth Doyle; Galecki, Grzegorz

    2013-07-02

    An abrasive cutting or drilling system, apparatus and method, which includes an upstream supercritical fluid and/or liquid carrier fluid, abrasive particles, a nozzle and a gaseous or low-density supercritical fluid exhaust abrasive stream. The nozzle includes a throat section and, optionally, a converging inlet section, a divergent discharge section, and a feed section.

  8. Method and apparatus for jet-assisted drilling or cutting

    DOEpatents

    Summers, David Archibold; Woelk, Klaus Hubert; Oglesby, Kenneth Doyle; Galecki, Grzegorz

    2012-09-04

    An abrasive cutting or drilling system, apparatus and method, which includes an upstream supercritical fluid and/or liquid carrier fluid, abrasive particles, a nozzle and a gaseous or low-density supercritical fluid exhaust abrasive stream. The nozzle includes a throat section and, optionally, a converging inlet section, a divergent discharge section, and a feed section.

  9. Method and apparatus for water jet drilling of rock

    DOEpatents

    Summers, David A.; Mazurkiewicz, Marian; Bushnell, Dwight J.; Blaine, James

    1978-01-01

    Rock drilling method and apparatus utilizing high pressure water jets for drilling holes of relatively small diameter at speeds significantly greater than that attainable with existing drilling tools. Greatly increased drilling rates are attained due to jet nozzle geometry and speed of rotation. The jet nozzle design has two orifices, one pointing axially ahead in the direction of travel and the second inclined at an angle of approximately 30.degree. from the axis. The two orifices have diameters in the ratio of approximately 1:2. Liquid jet velocities in excess of 1,000 ft/sec are used, and the nozzle is rotated at speeds up to 1,000 rpm and higher.

  10. Design method of water jet pump towards high cavitation performances

    NASA Astrophysics Data System (ADS)

    Cao, L. L.; Che, B. X.; Hu, L. J.; Wu, D. Z.

    2016-05-01

    As one of the crucial components for power supply, the propulsion system is of great significance to the advance speed, noise performances, stabilities and other associated critical performances of underwater vehicles. Developing towards much higher advance speed, the underwater vehicles make more critical demands on the performances of the propulsion system. Basically, the increased advance speed requires the significantly raised rotation speed of the propulsion system, which would result in the deteriorated cavitation performances and consequently limit the thrust and efficiency of the whole system. Compared with the traditional propeller, the water jet pump offers more favourite cavitation, propulsion efficiency and other associated performances. The present research focuses on the cavitation performances of the waterjet pump blade profile in expectation of enlarging its advantages in high-speed vehicle propulsion. Based on the specifications of a certain underwater vehicle, the design method of the waterjet blade with high cavitation performances was investigated in terms of numerical simulation.

  11. Abrasion protection in process piping

    SciTech Connect

    Accetta, J.

    1996-07-01

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

  12. Circular Signs of the Rock Abrasion Tool

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

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

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

  13. Abrasion resistant composition

    SciTech Connect

    Fischer, Keith D; Barnes, Christopher A; Henderson, Stephen L

    2014-05-13

    A surface covering composition of abrasion resistant character adapted for disposition in overlying bonded relation to a metal substrate. The surface covering composition includes metal carbide particles within a metal matrix at a packing factor of not less than about 0.6. Not less than about 40 percent by weight of the metal carbide particles are characterized by an effective diameter in the range of +14-32 mesh prior to introduction to the metal matrix. Not less than about 3 percent by weight of the metal carbide particles are characterized by an effective diameter of +60 mesh prior to introduction to the metal matrix.

  14. Degradation of Dome Cutting Minerals in Hanford Waste - 13100

    SciTech Connect

    Reynolds, Jacob G.; Cooke, Gary A.; Huber, Heinz J.

    2013-07-01

    At the Hanford Tank Farms, recent changes in retrieval technology require cutting new risers in several single-shell tanks. The Hanford Tank Farm Operator is using water jet technology with abrasive silicate minerals such as garnet or olivine to cut through the concrete and rebar dome. The abrasiveness of these minerals, which become part of the high-level waste stream, may enhance the erosion of waste processing equipment. However, garnet and olivine are not thermodynamically stable in Hanford waste, slowly degrading over time. How likely these materials are to dissolve completely in the waste before the waste is processed in the Waste Treatment and Immobilization Plant can be evaluated using theoretical analysis for olivine and collected direct experimental evidence for garnet. Based on an extensive literature study, a large number of primary silicates decompose into sodalite and cancrinite when exposed to Hanford waste. Given sufficient time, the sodalite also degrades into cancrinite. Even though cancrinite has not been directly added to any Hanford tanks during process times, it is the most common silicate observed in current Hanford waste. By analogy, olivine and garnet are expected to ultimately also decompose into cancrinite. Garnet used in a concrete cutting demonstration was immersed in a simulated supernate representing the estimated composition of the liquid retrieving waste from Hanford tank 241-C-107 at both ambient and elevated temperatures. This simulant was amended with extra NaOH to determine if adding caustic would help enhance the degradation rate of garnet. The results showed that the garnet degradation rate was highest at the highest NaOH concentration and temperature. At the end of 12 weeks, however, the garnet grains were mostly intact, even when immersed in 2 molar NaOH at 80 deg. C. Cancrinite was identified as the degradation product on the surface of the garnet grains. In the case of olivine, the rate of degradation in the high

  15. Degradation of dome cutting minerals in Hanford waste

    SciTech Connect

    Reynolds, Jacob G.; Huber, Heinz J.; Cooke, Gary A.

    2013-01-11

    At the Hanford Tank Farms, recent changes in retrieval technology require cutting new risers in several single-shell tanks. The Hanford Tank Farm Operator is using water jet technology with abrasive silicate minerals such as garnet or olivine to cut through the concrete and rebar dome. The abrasiveness of these minerals, which become part of the high-level waste stream, may enhance the erosion of waste processing equipment. However, garnet and olivine are not thermodynamically stable in Hanford waste, slowly degrading over time. How likely these materials are to dissolve completely in the waste before the waste is processed in the Waste Treatment and Immobilization Plant can be evaluated using theoretical analysis for olivine and collected direct experimental evidence for garnet. Based on an extensive literature study, a large number of primary silicates decompose into sodalite and cancrinite when exposed to Hanford waste. Given sufficient time, the sodalite also degrades into cancrinite. Even though cancrinite has not been directly added to any Hanford tanks during process times, it is the most common silicate observed in current Hanford waste. By analogy, olivine and garnet are expected to ultimately also decompose into cancrinite. Garnet used in a concrete cutting demonstration was immersed in a simulated supernate representing the estimated composition of the liquid retrieving waste from Hanford tank 241-C-107 at both ambient and elevated temperatures. This simulant was amended with extra NaOH to determine if adding caustic would help enhance the degradation rate of garnet. The results showed that the garnet degradation rate was highest at the highest NaOH concentration and temperature. At the end of 12 weeks, however, the garnet grains were mostly intact, even when immersed in 2 molar NaOH at 80 deg C. Cancrinite was identified as the degradation product on the surface of the garnet grains. In the case of olivine, the rate of degradation in the high-pH regimes

  16. APPLICATION OF WATER-JET HORIZONTAL DRILLING TECHNOLOGY TO DRILL AND ACIDIZE HORIZONTAL DRAIN HOLES, TEDBIT (SAN ANDRES) FIELD, GAINES COUNTY, TEXAS

    SciTech Connect

    Michael W. Rose

    2005-09-22

    The San Andres Formation is one of the major hydrocarbon-producing units in the Permian Basin, with multiple reservoirs contained within the dolomitized subtidal portions of upward shoaling carbonate shelf cycles. The test well is located in Tedbit (San Andres) Field in northeastern Gaines County, Texas, in an area of scattered San Andres production associated with local structural highs. Selected on the basis of geological and historical data, the Oil and Gas Properties Wood No. 1 well is considered to be typical of a large number of San Andres stripper wells in the Permian Basin. Thus, successful completion of horizontal drain holes in this well would demonstrate a widely applicable enhanced recovery technology. Water-jet horizontal drilling is an emerging technology with the potential to provide significant economic benefits in marginal wells. Forecast benefits include lower recompletion costs and improved hydrocarbon recoveries. The technology utilizes water under high pressure, conveyed through small-diameter coiled tubing, to jet horizontal drain holes into producing formations. Testing of this technology was conducted with inconclusive results. Paraffin sludge and mechanical problems were encountered in the wellbore, initially preventing the water-jet tool from reaching the kick-off point. After correcting these problems and attempting to cut a casing window with the water-jet milling assembly, lateral jetting was attempted without success.

  17. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    NASA Astrophysics Data System (ADS)

    Koita, T.; Zhu, Y.; Sun, M.

    2016-05-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  18. Abrasion-resistant antireflective coating for polycarbonate

    NASA Technical Reports Server (NTRS)

    Wydeven, T. J.

    1978-01-01

    Following plasma-polymerization technique, treatment in oxygen glow discharge further enhances abrasion resistance and transmission. Improvement in abrasion resistance was shown by measuring percentage of haze resulting from abrasion. Coating samples were analyzed for abrasion using standard fresh rubber eraser. Other tests included spectra measurements and elemental analysis with spectrometers and spectrophotometers.

  19. Transparent, abrasion resistant coating compositions

    SciTech Connect

    Ashlock, L.T.; Mukamal, H.; White, W.H.

    1985-02-19

    There is disclosed transparent, abrasion resistant coating compositions comprising a colloidal dispersion of a water insoluble dispersant in a water-alcohol solution of the partial condensate of silanol wherein the dispersant comprises metals, alloys and salts thereof.

  20. Abrasives in snuff?

    PubMed

    Dahl, B L; Stølen, S O; Oilo, G

    1989-08-01

    The purpose of this study was to determine and calculate the inorganic contents of four brands of snuff. Visual inspection of wet snuff showed fairly large, yellow crystal-like particles. Scanning electron microscopy and X-ray dispersive (EDX) analyses were used to study both wet snuff and ashes of snuff, whereas light emission spectrography was used to determine elements in the ashes. The crystal-like particles did not dissolve in distilled water or in ethanol heated to 60 degrees C. EDX analyses showed that most elements remained in the particles after washing. The total weight percentage of inorganic material in snuff was calculated after burning dried snuff until constant weight was obtained. The ashes of snuff did not contain any crystal-like particles but consisted of a small-grained amorphous mass. The following elements were detected: Ag, Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Pb, Si, Sr, Ti, Va, and Zr. Other elements such as rare earths were not searched for. The weight percentage of inorganic elements ranged between 12.35 +/- 0.69 and 20.95 +/- 0.81. Provided snuff is used in the same manner as chewing tobacco, and some people admit to doing so, there is a risk that its relatively high contents of inorganic material and heavily soluble salts may be conducive to excessive abrasion of teeth and restorations. PMID:2782061

  1. A Profilometric Study to Assess the Role of Toothbrush and Toothpaste in Abrasion Process

    PubMed Central

    Kumar, Sandeep; Kumar Singh, Siddharth; Gupta, Anjali; Roy, Sayak; Sareen, Mohit; Khajuria, Sarang

    2015-01-01

    Statement of the Problem Despite of many studies conducted on toothbrushes and toothpaste to find out the culprit for abrasion, there is no clear cut evidence to pin point the real cause for abrasion. Purpose An in vitro assessment of the role of different types of toothbrushes (soft/ medium/hard) in abrasion process when used in conjunction with and without a dentifrice. Materials and Method Forty five freshly extracted, sound, human incisor teeth were collected for this study. Enamel specimens of approximately 9 mm2 were prepared by gross trimming of extracted teeth using a lathe machine (Baldor 340 Dental lathe; Ohio, USA). They were mounted on separate acrylic bases. The specimens were divided into three groups, each group containing 15 mounted specimens. Group 1 specimens were brushed with soft toothbrush; Group 2 brushed with medium toothbrush and Group 3 with hard toothbrush. Initially, all the mounted specimens in each group were brushed using dentifrice and then the same procedure was repeated with water as control. Profilometric readings were recorded pre and post to tooth brushing and the differences in readings served as proxy measure to assess surface abrasion. These values were then compared to each other. Kruskal Wallis and Mann-Whitney U test were performed. Results The results showed that brushing, with water alone, caused less abrasion than when toothpaste was added (p< 0.008). When brushed with water, the harder toothbrush caused more abrasion (higher Ra-value), but when toothpaste was added, the softer toothbrush caused more abrasion (p< 0.001). Conclusion Besides supporting the fact that toothpaste is needed to create a significant abrasion, this study also showed that a softer toothbrush can cause more abrasion than harder ones. The flexibility of bristles is only secondary to abrasion process and abrasivity of dentifrice has an important role in abrasion process. PMID:26535407

  2. Conduit Coating Abrasion Testing

    NASA Technical Reports Server (NTRS)

    Sullivan, Mary K.

    2013-01-01

    During my summer internship at NASA I have been working alongside the team members of the RESTORE project. Engineers working on the RESTORE project are creating ·a device that can go into space and service satellites that no longer work due to gas shortage or other technical difficulties. In order to complete the task of refueling the satellite a hose needs to be used and covered with a material that can withstand effects of space. The conduit coating abrasion test will help the researchers figure out what type of thermal coating to use on the hose that will be refueling the satellites. The objective of the project is to determine whether or not the conduit coating will withstand the effects of space. For the RESTORE project I will help with various aspects of the testing that needed to be done in order to determine which type of conduit should be used for refueling the satellite. During my time on the project I will be assisting with wiring a relay board that connected to the test set up by soldering, configuring wires and testing for continuity. Prior to the testing I will work on creating the testing site and help write the procedure for the test. The testing will take place over a span of two weeks and lead to an informative conclusion. Working alongside various RESTORE team members I will assist with the project's documentation and records. All in all, throughout my internship at NASA I hope to learn a number of valuable skills and be a part of a hard working team of engineers.

  3. Influence of Corrosion on the Abrasion of Cutter Steels Used in TBM Tunnelling

    NASA Astrophysics Data System (ADS)

    Espallargas, N.; Jakobsen, P. D.; Langmaack, L.; Macias, F. J.

    2015-01-01

    Abrasion on tunnel boring machine (TBM) cutters may be critical in terms of project duration and costs. Several researchers are currently studying the degradation of TBM cutter tools used for excavating hard rock, soft ground and loose soil. So far, the primary focus of this research has been directed towards abrasive wear. Abrasive wear is a very common process in TBM excavation, but with a view to the environment in which the tools are working, corrosion may also exert an influence. This paper presents a selection of techniques that can be used to evaluate the influence of corrosion on abrasion on TBM excavation tools. It also presents the influence of corrosion on abrasive wear for some initial tests, with constant steel and geomaterial and varying properties of the excavation fluids (soil conditioners, anti-abrasion additives and water). The results indicate that the chloride content in the water media greatly influences the amount of wear, providing evidence of the influence of corrosion on the abrasion of the cutting tools. The presence of conditioning additives tailored to specific rock or soil conditions reduces wear. However, when chloride is present in the water, the additives minimise wear rates but fail to suppress corrosion of the cutting tools.

  4. Degradation of C.I. Reactive Red 2 through photocatalysis coupled with water jet cavitation.

    PubMed

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2011-01-15

    The decolorization of an azo dye, C.I. Reactive Red 2 was investigated using TiO(2) photocatalysis coupled with water jet cavitation. Experiments were performed in a 4.0 L solution under ultraviolet power of 9 W. The effects of TiO(2) loading, initial dye concentration, solution pH, geometry of cavitation tube, and the addition of anions on the degradation of the dye were evaluated. Degradation of the dye followed a pseudo-first order reaction. The photocatalysis coupled with water jet cavitation elevated degradation of the dye by about 136%, showing a synergistic effect compared to the individual photocatalysis and water jet cavitation. The enhancement of photocatalysis by water jet cavitation could be due to the deagglomeration of catalyst particles as well as the better contact between the catalyst surfaces and the reactants. Venturi tube with smaller diameter and shorter length of throat tube favored the dye decolorization. The degradation efficiency was found to increase with decreasing initial concentration and pH. The presence of NO(3)(-) and SO(4)(2-) enhanced the degradation of RR2, while Cl(-), and especially HCO(3)(-) significantly reduced dye decolorization. The results of this study indicated that the coupled photocatalysis and water jet cavitation is effective in degrading dye in wastewater and provides a promising alternative for treatment of dye wastewater at a large scale.

  5. Separation of the tumor and brain surface by "water jet" in cases of meningiomas.

    PubMed

    Toth, S; Vajda, J; Pasztor, E; Toth, Z

    1987-01-01

    In the surgery of meningiomas one of the most delicate problems is the separation of the tumor from the brain surface. The authors generally recommend microsurgery to preserve the brain surface anatomically and functionally. For this purpose we have developed a new surgical technique according to our concepts of tissue care. After excavating the tumor from inside the tumor brain surface was separated by repeated "water jets" into the tumor arachnoideal space. The "water jet" was produced by an ordinary bulb syringe. The front pressure of the jets was 300-1000 mm of water and the side pressure 100-300 mm of water. In the tumor-arachnoideal space the spreading water (phys. NaCl) separates the brain from the tumor with utmost care. We operated on 55 meningiomas of different types with the "water jet" technique. The immediate results were anatomically excellent. Intraoperative and postoperative acute and late edemas appeared only in a few cases. The functions of the nearby brain were generally preserved. The surgery was uneventful when the tumor surface was smooth and the tumor was spherical. When the tumor surface was uneven, one part of the tumor extended under the dura as a thin layer or the tumor was multilobulated with expanded vessels between the lobules, more microseparation was necessary. We compared the results of the "water jet" technique with the results of the "pre-water jet" series. The surgery with the "water jet" technique was much shorter and its results were better than those of microsurgery alone. PMID:3668608

  6. Radiated Sound of a High-Speed Water-Jet-Propelled Transportation Vessel.

    PubMed

    Rudd, Alexis B; Richlen, Michael F; Stimpert, Alison K; Au, Whitlow W L

    2016-01-01

    The radiated noise from a high-speed water-jet-propelled catamaran was measured for catamaran speeds of 12, 24, and 37 kn. The radiated noise increased with catamaran speed, although the shape of the noise spectrum was similar for all speeds and measuring hydrophone depth. The spectra peaked at ~200 Hz and dropped off continuously at higher frequencies. The radiated noise was 10-20 dB lower than noise from propeller-driven ships at comparable speeds. The combination of low radiated noise and high speed could be a factor in the detection and avoidance of water-jet-propelled ships by baleen whales. PMID:26611054

  7. Radiated Sound of a High-Speed Water-Jet-Propelled Transportation Vessel.

    PubMed

    Rudd, Alexis B; Richlen, Michael F; Stimpert, Alison K; Au, Whitlow W L

    2016-01-01

    The radiated noise from a high-speed water-jet-propelled catamaran was measured for catamaran speeds of 12, 24, and 37 kn. The radiated noise increased with catamaran speed, although the shape of the noise spectrum was similar for all speeds and measuring hydrophone depth. The spectra peaked at ~200 Hz and dropped off continuously at higher frequencies. The radiated noise was 10-20 dB lower than noise from propeller-driven ships at comparable speeds. The combination of low radiated noise and high speed could be a factor in the detection and avoidance of water-jet-propelled ships by baleen whales.

  8. Fabrication of low cost cutting wheel via thermal spray process

    NASA Astrophysics Data System (ADS)

    Anasyida, A. S.; Nurulakmal, M. S.

    2012-09-01

    The present study is mainly focused on development of metal cutting wheel. The process involved hard particles (abrasives) being bonded on the wheel to enhance the cutting capability by thermal spraying process and followed by polymer bonding. The purpose of this work is to produce low cost cutting wheel and study the performance of cutting behavior. Two different types of powders; silicon carbide (SiC) as bonding agent and chromium carbide (Cr3C2) as abrasives were used. Wear loss and depth of cut as function of load, cutting time and cutting speed were evaluated. The results showed that the speed and load were the main factors that affected the cutting efficiency and the optimum cutting process can be performed at low cutting speed and high load or at high cutting speed and low load.

  9. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  10. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  11. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  12. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  13. Ultra-high pressure water jet: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The Husky{trademark} is an ultra high pressure waterjet cutting tool system. The pump is mounted on a steel tube frame which includes slots for transport by a forklift. The Husky{trademark} features an automatic shutdown for several conditions such as low oil pressure and high oil temperature. Placement of the Husky{trademark} must allow for a three foot clearance on all sides for operation and service access. At maximum continuous operation, the output volume is 7.2 gallons per minute with an output pressure of 40,000 psi. A diesel engine provides power for the system. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  14. Ultra-high pressure water jet: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The ultra-high pressure waterjet technology was 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 ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The technologies being tested for concrete decontamination are targeted for alpha contamination. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  15. Prediction Of Abrasive And Diffusive Tool Wear Mechanisms In Machining

    NASA Astrophysics Data System (ADS)

    Rizzuti, S.; Umbrello, D.

    2011-01-01

    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.

  16. [Usefulness of pulsed water jet in dissecting sphenoid ridge meningioma while preserving arteries].

    PubMed

    Endo, Toshiki; Nakagawa, Atsuhiro; Fujimura, Miki; Sonoda, Yukihiko; Shimizu, Hiroaki; Tominaga, Teiji

    2014-11-01

    We report the utility of a pulsed water jet device in meningioma surgery. The presented case is that of a 61-year-old woman with left visual disturbance. MRI demonstrated heterogeneously enhanced mass with intratumoral hemorrhage, indicating sphenoid ridge meningioma on her left side. The tumor invaded the cavernous sinus and left optic canal, engulfing the internal carotid artery in the carotid cistern and encased middle cerebral arteries. During the operation, the pulsed water jet device was useful for dissecting the tumor away from the arteries since it was safe in light of preserving parent arteries. The jet did not cause any vascular injury and did not induce vasospasm as shown by postoperative symptomatology and MRIs. With the aid of pulsed water jet, we could achieve total resection of the tumor except for the piece within the cavernous sinus. The patient had no new neurological deficits after the operation. We consider the pulsed water jet as a useful device, especially when the need to dissect meningioma from parent arteries exists. The jet can help neurosurgeons simultaneously achieve tumor resection and preservation of blood vessels.

  17. Non-contact measurements of water jet spreading width with a laser instrument

    NASA Astrophysics Data System (ADS)

    Funami, Yuki; Hasuya, Ryo; Tanabe, Kotaro; Nakanishi, Yuji

    2016-08-01

    Jet spreading width is one of the important characteristics of water jets discharging into the air. Many researchers have dealt with measuring this width, and contact measuring methods on the water jet surface were employed in a lot of the cases. In order to avoid undesirable effects caused by the contact on the jet surface, we introduce non-contact measuring methods with a laser instrument to the measurements of jet spreading width. In measurements, a transmitter emits sheet-like laser beam to a receiver. The water jet between the transmitter and the receiver interrupts the laser beam and makes a shadow. The minimum and maximum values of the shadow width are measured. In addition, pictures of the water jet are taken with a scale, and the shadow width is measured from the pictures. The experiments on various needle strokes were performed. Three kinds of width consistent with the jet structure were obtained. In the results, it can be concluded that our non-contact measuring methods are feasible. The data of jet spreading widths and jet taper were obtained and are useful for future applications.

  18. Cutting with diamond wire: Cutting procedures and suggested uses

    NASA Astrophysics Data System (ADS)

    McLaughlin, H. B.

    Diamond impregnated wire is the most versatile cutting tool yet devised. When a wire is properly charged with diamond particles and is drawn back and forth over a material surface, it does a remarkable cutting job. In a number of cases, wire sawing is the only way to perform these operations successfully: (1) for materials which are so fragile that other means of cutting will cause breakage, damage to crystal structure or otherwise impair the specimens, often rendering them useless, (2) for cutting materials which are so expensive that kerf loss becomes a major factor, a wire of the proper diameter with carefully graded diamonds, results in the minimum loss of material, (3) for cutting materials which may be damaged by the frictional heat generated by the high speed abrasive wheels, band saws and other cutting devices, causing hair cracks and craze.

  19. Ultra-high pressure water jet: Baseline report

    SciTech Connect

    1997-07-31

    The ultra-high pressure waterjet technology was 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 ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems.

  20. Cubic boron nitride: tools and abrasives. January 1972-February 1989 (Citations from the US Patent data base). Report for January 1972-February 1989

    SciTech Connect

    Not Available

    1989-03-01

    This bibliography contains citations of selected patents concerning materials of cubic boron nitride (CBN) for machine tools and superhard abrasives. Included are methods of producing CBN compacts and abrasive structures for cutting tools, tool inserts, grinding wheels, wire drawing dies, gears, and drill bits. Bonding methods on various substrates are also presented. (Contains 146 citations fully indexed and including a title list.)

  1. Optimization of rock-cutting tools used in coal mining

    SciTech Connect

    Ford, L.M.; Friedman, M.

    1983-01-01

    Analytical, experimental, and observational studies have been conducted to gain a fundamental understanding of tool/rock interactions. This will allow optimization of designs for depth-of-cut, tool-spacing, kerfing, and water-jet assistance. Equations are developed that show optimum tool-spacing reduces cutting forces to nearly 50% of what a single tool requires; experimental data shows optimized kerf-depth reduces cutting forces 30% and increases volume of rock removed by a factor of about 2 or 3, thus decreasing the specific energy (compared to a single tool) by as much as 75%. Unconfined blocks of Tennessee Sandstone and Carthage Limestone were systematically grooved at depths-of-cut from 0.025 to 0.100 in. (.635 mm to 2.54 mm) with a flattened Austin AP24 Cutter while horizontal and vertical cutting forces are measured. Cutting force divided by depth-of-cut decreases with increasing depth-of-cut while cutting force divided by cross-sectional area of rock removed decreases with increasing depth-of-cut until about 0.080 in. (2.032 mm) and then increases. Water saturation reduces cutting forces by nearly 50% through lubrication and rock-strength degradation. Overall results suggest water-jet kerfing on either side of each tool could achieve 75% or more reduction in specific energy compared to a single tool. This would increase tool life, lower dust production and methane ignition probabilities, reduce equipment and maintenance costs, and allow inceasing production at lower per ton costs. Water-jet assistance ahead of the tool to increase macrofracturing also would decrease specific energy requirements.

  2. Considerations in the use of water jets to enlarge deep submerged cavities

    SciTech Connect

    Summers, D.A.; Sebastian, Z.

    1980-01-01

    In order to facilitate use of reinjection wells, and to lower their cost, it has been proposed that a single well be reamed from 22-1/2 cm to 2 m diameter over an increment of 70 m at a depth of 2000 m. In this manner a single well would be capable of coping with flow rates which currently necessitate a dozen wells being emplaced. The problems encountered in using high pressure water jets for this reaming operation are described. Limiting parameters on the use of high pressure water jets and their operating diameters are identified. The considerable advantages to the use of long chain polymers in such a hostile environment are also delineated.

  3. Atomization of water jets and sheets in axial and swirling airflows

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1977-01-01

    Axial and swirling airflows were used to break up water jets and sheets into sprays of droplets to determine the overall effects of orifice diameter, weight flow of air, and the use of an air swirler on fineness of atomization as characterized by mean drop size. A scanning radiometer was used to determine the mean drop diameter of each spray. Swirling airflows were produced with an axial combustor, 70 deg blake angle, air swirling. Water jets were injected axially upstream, axially downstream and cross stream into the airflow. In addition, pressure atomizing fuel nozzles which produced a sheet and ligament type of breakup were investigated. Increasing the weight flow rate of air or the use of an air swirling markedly reduced the spray mean drop size.

  4. Cubic boron nitride: Tools and abrasives. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1994-01-01

    The bibliography contains citations of selected patents concerning materials of cubic boron nitride (CBN) for machine tools and superhard abrasives. Included are methods of producing CBN compacts and abrasive structures for cutting tools, tool inserts, grinding wheels, wire drawing dies, gears, and drill bits. Bonding methods on various substrates are also presented. (Contains a minimum of 244 citations and includes a subject term index and title list.)

  5. Evaluation of bone-tendon junction healing using water jet ultrasound indentation method.

    PubMed

    Lu, Min-Hua; Zheng, Yong-Ping; Lu, Hong-Bin; Huang, Qing-Hua; Qin, Ling

    2009-11-01

    The re-establishment of bone-tendon junction (BTJ) tissues with the junction, characterized as a unique transitional fibrocartilage zone, is involved in many trauma and reconstructive surgeries. Experimental and clinical findings have shown that a direct BTJ repair requires a long period of immobilization, which may be associated with a postoperative weak knee. Therefore, it is necessary to evaluate the morphologic and mechanical properties of BTJ tissues in situ to better understand the healing process for the purpose of reducing the adverse effects of immobilization. We previously reported a noncontact ultrasound water jet indentation system for measuring and mapping tissue mechanical properties. The key idea was to utilize a water jet as an indenter as well as the coupling medium for high-frequency ultrasound. In this article, we used ultrasound water jet indentation to evaluate the BTJ healing process. The system's capability of measuring the material elastic modulus was first validated using tissue-mimicking phantoms. Then it was employed to assess the healing of the BTJ tissues after partial patellectomy over time on twelve 18-week-old female New Zealand White rabbits. It was found that in comparison with the normal control samples, the elastic modulus of the fibrocartilage of the postoperative samples was significantly smaller, while its thickness increased significantly. Among the postoperative sample groups, the elastic modulus of the fibrocartilage of the samples harvested at week 18 was significantly higher than those harvested at week 6 and week 12, which was even comparable with the value of the control samples at the same sacrifice time. The results suggested that the noncontact ultrasound water jet indentation system provided a nondestructive way to evaluate the material properties of small animal tissues in situ and thus had the ability to evaluate the healing process of BTJ.

  6. Experimental investigation of inclined liquid water jet flow onto vertically located superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kibar, Ali; Karabay, Hasan; Yiğit, K. Süleyman; Ucar, Ikrime O.; Erbil, H. Yıldırım

    2010-11-01

    In this study, the behaviour of an inclined water jet, which is impinged onto hydrophobic and superhydrophobic surfaces, has been investigated experimentally. Water jet was impinged with different inclination angles (15°-45°) onto five different hydrophobic surfaces made of rough polymer, which were held vertically. The water contact angles on these surfaces were measured as 102°, 112°, 123°, 145° and 167° showing that the last surface was superhydrophobic. Two different nozzles with 1.75 and 4 mm in diameters were used to create the water jet. Water jet velocity was within the range of 0.5-5 m/s, thus the Weber number varied from 5 to 650 and Reynolds number from 500 to 8,000 during the experiments. Hydrophobic surfaces reflected the liquid jet depending on the surface contact angle, jet inclination angle and the Weber number. The variation of the reflection angle with the Weber number showed a maximum value for a constant jet angle. The maximum value of the reflection angle was nearly equal to half of the jet angle. It was determined that the viscous drag decreases as the contact angle of the hydrophobic surface increases. The drag force on the wall is reduced dramatically with superhydrophobic surfaces. The amount of reduction of the average shear stress on the wall was about 40%, when the contact angle of the surface was increased from 145° to 167°. The area of the spreading water layer decreased as the contact angle of the surface increased and as the jet inclination angle, Weber number and Reynolds number decreased.

  7. Abrasive drill for resilient materials

    NASA Technical Reports Server (NTRS)

    Koch, A. J.

    1981-01-01

    Resilient materials normally present problem in obtaining accurate and uniform hole size and position. Tool is fabricated from stiff metal rod such as tungsten or carbon steel that has diameter slightly smaller than required hole. Piercing/centering point is ground on one end of rod. Rod is then plasma-sprayed (flame-sprayed) with suitable hard abrasive coating. High-speed, slow-feed operation of tool is necessary for accurate holes, and this can be done with drill press, hard drill, or similar machines.

  8. Stripping of thermal spray coatings with ultra high pressure water jet

    NASA Astrophysics Data System (ADS)

    Sohr, James M.; Thorpe, Merle L.

    1992-04-01

    The ultra high pressure water jet coating removal system uses supersonic jet(s) of water to completely remove tenaciously adhered coatings and debris from almost any part or substrate. It is differentiated from more conventional water cleaning techniques by much higher pressures which require unique pump, hydraulic and control systems. In the case of coatings, the water jet hits the surface with such a force that the coating fractures, spalls, and erodes without causing part damage. In the case of other contamination, the jet enters the smaller holes and crevices to remove all contamination. The energy in the supersonic water jet stream is provided by an intensifier that pumps water pressure in the range of 40,000 to 60,000 psi through one or more small diameter orifices. Removal alternatives are briefly discussed, however the papers major emphasis is in the characterization of the process for removing thermally sprayed coating on jet engine parts. The performance of various nozzle designs are discussed along with system requirement.

  9. Study on Turbulent Behavior of Water Jet in Supersonic Steam Injector

    NASA Astrophysics Data System (ADS)

    Fukuichi, Akira; Abe, Yutaka; Fujiwara, Akiko; Kawamoto, Yujiro; Iwaki, Chikako; Narabayashi, Tadashi; Mori, Michitsugu; Ohmori, Shuichi

    One of the most interesting devices for light water reactor systems aimed at simplified system, improvement of safety and reliability is a supersonic steam injector. Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of direct contact condensation between supersonic steam and a subcooled water jet. It is considered that flow behavior in the supersonic steam injector is related to complicated turbulent flow with large shear stress induced by velocity difference between steam and water and direct contact condensation. However, studies about turbulent flow under large shear stress with direct contact condensation are not enough. Especially, mechanisms of momentum and heat transfer are not clarified in detail. Objective of the present study is to investigate turbulent behaviors of a water jet and interface that play an important role in heat transfer and momentum transfer. Radial distribution of streamwise velocity and fluctuation of total pressure are measured by a pitot measurement. Visual measurement of the turbulent water jet is conducted by a high speed camera in order to identify location of unstable interface and its behavior. It is found that streamwise velocity increases as it approaches downstream of the mixing nozzle. Fluctuation of total pressure is large at water-steam mixture region. It is confirmed that waves propagated on the interface. And its velocity is obtained.

  10. Investigation of Turbulent Tip Leakage Vortex in an Axial Water Jet Pump with Large Eddy Simulation

    NASA Technical Reports Server (NTRS)

    Hah, Chunill; Katz, Joseph

    2012-01-01

    Detailed steady and unsteady numerical studies were performed to investigate tip clearance flow in an axial water jet pump. The primary objective is to understand physics of unsteady tip clearance flow, unsteady tip leakage vortex, and cavitation inception in an axial water jet pump. Steady pressure field and resulting steady tip leakage vortex from a steady flow analysis do not seem to explain measured cavitation inception correctly. The measured flow field near the tip is unsteady and measured cavitation inception is highly transient. Flow visualization with cavitation bubbles shows that the leakage vortex is oscillating significantly and many intermittent vortex ropes are present between the suction side of the blade and the tip leakage core vortex. Although the flow field is highly transient, the overall flow structure is stable and a characteristic frequency seems to exist. To capture relevant flow physics as much as possible, a Reynolds-averaged Navier-Stokes (RANS) calculation and a Large Eddy Simulation (LES) were applied for the current investigation. The present study reveals that several vortices from the tip leakage vortex system cross the tip gap of the adjacent blade periodically. Sudden changes in local pressure field inside tip gap due to these vortices create vortex ropes. The instantaneous pressure filed inside the tip gap is drastically different from that of the steady flow simulation. Unsteady flow simulation which can calculate unsteady vortex motion is necessary to calculate cavitation inception accurately even at design flow condition in such a water jet pump.

  11. Median Nerve Injury Due to High-Pressure Water Jet Injection: A Case Report and Review of Literature.

    PubMed

    Emre, Ufuk; Unal, Aysun

    2009-08-01

    High-pressure injuries that occur accidentally are potentially destructive injuries that often affect the nondominant hands of young men. A variety of products such as paint, gasoline, grease, fuel oil, cement, thinner and solvents have been reported as destructive agents. High-pressure water jet injection injuries to soft tissues have rarely been reported. In this study, we present the first case of median nerve injury due to high-pressure water jet injection by a water spray gun. PMID:26815059

  12. Ultrasonic Abrasive Removal Of EDM Recast

    NASA Technical Reports Server (NTRS)

    Mandel, Johnny L.; Jacobson, Marlowe S.

    1990-01-01

    Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

  13. Ceramic-bonded abrasive grinding tools

    DOEpatents

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

    1994-11-22

    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.

  14. Ceramic-bonded abrasive grinding tools

    SciTech Connect

    Holcombe, Jr., Cressie E.; Gorin, Andrew H.; Seals, Roland D.

    1994-01-01

    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.

  15. Wire blade development for Fixed Abrasive Slicing Technique (FAST) slicing

    NASA Astrophysics Data System (ADS)

    Khattak, C. P.; Schmid, F.; Smith, M. B.

    1982-02-01

    A low cost, effective slicing method is essential to make ingot technology viable for photovoltaics in terrestrial applications. The fixed abrasive slicing technique (FAST) combines the advantages of the three commercially developed techniques. In its development stage FAST demonstrated cutting effectiveness of 10 cm and 15 cm diameter workpieces. Wire blade development is still the critical element for commercialization of FAST technology. Both impregnated and electroplated wire blades have been developed; techniques have been developed to fix diamonds only in the cutting edge of the wire. Electroplated wires show the most near term promise and this approach is emphasized. With plated wires it has been possible to control the size and shape of the electroplating, it is expected that this feature reduces kerf and prolongs the life of the wirepack.

  16. Wire blade development for Fixed Abrasive Slicing Technique (FAST) slicing

    NASA Technical Reports Server (NTRS)

    Khattak, C. P.; Schmid, F.; Smith, M. B.

    1982-01-01

    A low cost, effective slicing method is essential to make ingot technology viable for photovoltaics in terrestrial applications. The fixed abrasive slicing technique (FAST) combines the advantages of the three commercially developed techniques. In its development stage FAST demonstrated cutting effectiveness of 10 cm and 15 cm diameter workpieces. Wire blade development is still the critical element for commercialization of FAST technology. Both impregnated and electroplated wire blades have been developed; techniques have been developed to fix diamonds only in the cutting edge of the wire. Electroplated wires show the most near term promise and this approach is emphasized. With plated wires it has been possible to control the size and shape of the electroplating, it is expected that this feature reduces kerf and prolongs the life of the wirepack.

  17. Cleaning power and abrasivity of European toothpastes.

    PubMed

    Wülknitz, P

    1997-11-01

    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 a V8 cross-brushing machine, and brightness measurement by a chromametric technique. All tested products were in accordance with the new DIN/ISO standard 11,609 for toothpastes in terms of dentin abrasivity. Not a single product exceeded an RDA value of 200. The majority of toothpastes (80%) had an RDA value below 100. Only three products surpassed the reference in cleaning power. Most products (73%) had a cleaning power (PCR value) between 20 and 80. The correlation between cleaning power and dentin abrasion was low (r = 0.66), which can be explained with the different influence on dentin and stains by factors like abrasive type, particle surface and size, as well as the chemical influence of other toothpaste ingredients. Some major trends could be shown on the basis of abrasive types. The ratio PCR to RDA was rather good in most silica-based toothpastes. A lower ratio was found in some products containing calcium carbonate or aluminum trihydrate as the only abrasive. The addition of other abrasives, such as polishing alumina, showed improved cleaning power. Some active ingredients, especially sequenstrants such as sodium tripolyphosphate or AHBP, also improve the PCR/RDA ratio by stain-dissolving action without being abrasive. The data for some special anti-stain products did not differ significantly from standard products. Compared with data measured in 1988, a general trend toward reduced abrasivity without loss of cleaning efficacy could be noticed on the European toothpaste market. This may be mostly due to the increased use of high-performance abrasives such

  18. Automation of cutting and drilling of composite components

    NASA Technical Reports Server (NTRS)

    Warren, Charles W.

    1991-01-01

    The task was to develop a preliminary plan for an automated system for the cutting and drilling of advanced aerospace composite components. The goal was to automate the production of these components, but the technology developed can be readily extended to other systems. There is an excellent opportunity for developing a state of the art automated system for the cutting and drilling of large composite components at NASA-Marshall. Most of the major system components are in place: the robot, the water jet pump, and the off-line programming system. The drilling system and the part location system are the only major components that need to be developed. Also, another water jet nozzle and a small amount of high pressure plumbing need to be purchased from, and installed.

  19. Dynamic voltage-current characteristics for a water jet plasma arc

    SciTech Connect

    Yang Jiaxiang; Lan Sheng; Xu Zuoming

    2008-05-05

    A virtual instrument technology is used to measure arc current, arc voltage, dynamic V-I characteristics, and nonlinear conductance for a cone-shaped water jet plasma arc under ac voltage. Experimental results show that ac arc discharge mainly happens in water vapor evaporated from water when heated. However, due to water's cooling effect and its conductance, arc conductance, reignition voltage, extinguish voltage, and current zero time are very different from those for ac arc discharge in gas work fluid. These can be valuable to further studies on mechanism and characteristics of plasma ac discharge in water, and even in gas work fluid.

  20. The abrasion and impact-abrasion behavior of austempered ductile irons

    SciTech Connect

    Hawk, Jeffrey A.; Dogan, Omer N.; Lerner, Y.S.

    1998-01-01

    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

  1. Gusev crater: direction of active winds derived from the Mars Exploration Rover Rock Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Greeley, R.; Gorevan, S.; Thompson, S. D.; Whelley, P.; Squyres, S.; Arvidson, R.

    2004-05-01

    The Mars Exploration Rovers (MERs) are not instrumented to measure winds directly, but might be able to give insight into wind directions using other techniques. The Rock Abrasion Tool (RAT) on the Instrument Deployment Device (IDD) on the Mars rover, Spirit, was used to remove dust and cut into a basaltic rock named Adirondack in Gusev crater on Sol 34 of mission operations. The rock abrasion operation occurred between about 1223 hr and 1518 hr in the afternoon (local solar time) and left a cavity 2.68 mm deep. An image taken after the abrasion operation showed that the rock cuttings were asymmetrically distributed around the cavity and over the rock in a direction suggesting that the cuttings were transported away from the cavity by winds. The distribution pattern (and the inferred wind) is being compared with results from wind tunnel simulations conducted prior to the mission to assess the wind-flow patterns as a function of rock, rover, and IDD positions with respect to the wind. The wind direction inferred from the RAT cuttings are also being compared with wind directions suggested by aeolian bedforms and albedo patterns seen from MER and from orbit, and with directions predicted by a model of the atmosphere for winds at mid-day in Gusev crater.

  2. Influence of sodium content on the properties of bioactive glasses for use in air abrasion.

    PubMed

    Farooq, Imran; Tylkowski, Maxi; Müller, Steffen; Janicki, Tomasz; Brauer, Delia S; Hill, Robert G

    2013-12-01

    Air abrasion is used in minimally invasive dentistry for preparing cavities, while removing no or little sound dentine or enamel, and the use of bioactive glass (rather than alumina) as an abrasive could aid in tooth remineralization. Melt-derived bioactive glasses (SiO2-P2O5-CaO-CaF2-Na2O) with low sodium content (0 to 10 mol% Na2O in exchange for CaO) for increased hardness, high phosphate content for high bioactivity and fluoride content for release of fluoride and formation of fluorapatite were produced, and particles between 38 and 80 µm in size were used for cutting soda-lime silicate glass microscope slides and human enamel. Vickers hardness increased with decreasing Na2O content, owing to a more compact silicate network in low sodium content glasses, resulting in shorter cutting times. Cutting times using bioactive glass were significantly longer than using the alumina control (29 µm) when tested on microscope slides; however, glasses showed more comparable results when cutting human enamel. The bioactive glasses formed apatite in Tris buffer within 6 h, which was significantly faster than Bioglass® 45S5 (24 h), suggesting that the hardness of the glasses makes them suitable for air abrasion application, while their high bioactivity and fluoride content make them of interest for tooth remineralization.

  3. Influence of sodium content on the properties of bioactive glasses for use in air abrasion.

    PubMed

    Farooq, Imran; Tylkowski, Maxi; Müller, Steffen; Janicki, Tomasz; Brauer, Delia S; Hill, Robert G

    2013-12-01

    Air abrasion is used in minimally invasive dentistry for preparing cavities, while removing no or little sound dentine or enamel, and the use of bioactive glass (rather than alumina) as an abrasive could aid in tooth remineralization. Melt-derived bioactive glasses (SiO2-P2O5-CaO-CaF2-Na2O) with low sodium content (0 to 10 mol% Na2O in exchange for CaO) for increased hardness, high phosphate content for high bioactivity and fluoride content for release of fluoride and formation of fluorapatite were produced, and particles between 38 and 80 µm in size were used for cutting soda-lime silicate glass microscope slides and human enamel. Vickers hardness increased with decreasing Na2O content, owing to a more compact silicate network in low sodium content glasses, resulting in shorter cutting times. Cutting times using bioactive glass were significantly longer than using the alumina control (29 µm) when tested on microscope slides; however, glasses showed more comparable results when cutting human enamel. The bioactive glasses formed apatite in Tris buffer within 6 h, which was significantly faster than Bioglass® 45S5 (24 h), suggesting that the hardness of the glasses makes them suitable for air abrasion application, while their high bioactivity and fluoride content make them of interest for tooth remineralization. PMID:24287337

  4. Atomization of water jets and sheets in axial and swirling airflows

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1979-01-01

    Axial and swirling airflows were used to break up water jets and sheets into sprays of droplets to determine the overall effects of orifice diameter, weight flow of air, and the use of an air swirler on fineness of atomization as characterized by mean drop size. A scanning radiometer was used to determine the mean drop diameter of each spray. Swirling airflows were produced with an axial combustor, 70 deg blake angle, air swirling. Water jets were injected axially upstream, axially downstream and cross stream into the airflow. In addition, pressure atomizing fuel nozzles which produced a sheet and ligament type of breakup were investigated. Increasing the weight flow rate of air or the use of an air swirling markedly reduced the spray mean drop size. Test conditions included a water flow rate of 68.0 liter per hour and airflow rates (per unit area) of 3.7 to 25.7 g per square cm per sec, at 293 K and inlet-air static pressures of 1.01 x 10 to the 5th to 1.98 x 10 to the 5th N/sq m.

  5. Surface assessment and modification of concrete using abrasive blasting

    NASA Astrophysics Data System (ADS)

    Millman, Lauren R.

    Composite systems are applied to concrete substrates to strengthen and extend the service life. Successful restoration or rehabilitation requires surface preparation prior to the application of the overlay. Surface coatings, waterproofing systems, and other external surface applications also require surface preparation prior to application. Abrasive blast media is often used to clean and uniformly roughen the substrate. The appropriate surface roughness is necessary to facilitate a strong bond between the existing substrate and overlay. Thus, surface modification using abrasive blast media (sand and dry ice), their respective environmental effects, surface roughness characterization prior to and after blasting, and the adhesion between the substrate and overlay are the focus of this dissertation. This dissertation is comprised of an introduction, a literature review, and four chapters, the first of which addresses the environmental effects due to abrasive blasting using sand, water, and dry ice. The assessment considered four response variables: carbon dioxide (CO2) emissions, fuel and energy consumption, and project duration. The results indicated that for sand blasting and water jetting, the primary factor contributing to environmental detriment was CO22 emissions from vehicular traffic near the construction site. The second chapter is an analysis of the International Concrete Repair Institute's (ICRI) concrete surface profiles (CSPs) using 3-D optical profilometry. The primary objective was to evaluate the suitability of approximating the 3-D surface (areal) parameters with those extracted from 2-D (linear) profiles. Four profile directions were considered: two diagonals, and lines parallel and transverse to the longitudinal direction of the mold. For any CSP mold, the estimation of the 3-D surface roughness using a 2-D linear profile resulted in underestimation and overestimation errors exceeding 50%, demonstrating the inadequacy of 2-D linear profiles to

  6. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  7. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  8. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  9. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  10. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  11. Abrasion by aeolian particles: Earth and Mars

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Marshall, J. R.; White, B. R.; Pollack, J. B.; Marshall, J.; Krinsley, D.

    1984-01-01

    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 obtained in the laboratory and combined with wind data from the Viking meteorology experiment. Assuming an abundant supply of sand-sized particles, estimated rates range up to 2.1 x 10 to the minus 2 power cm of abrasion per year in the vicinity of Viking Lander 1. This rate is orders of magnitude too great to be in agreement with the inferred age of the surface based on models of impact crater flux. The discrepancy in the estimated rate of abrasion and the presumed old age of the surface cannot be explained easily by changes in climate or exhumation of ancient surfaces. The primary reason is thought to be related to the agents of abrasion. At least some sand-sized (approx. 100 micrometers) grains appear to be present, as inferred from both lander and orbiter observations. High rates of abrasion occur for all experimental cases involving sands of quartz, basalt, or ash. However, previous studies have shown that sand is quickly comminuted to silt- and clay-sized grains in the martian aeolian regime. Experiments also show that these fine grains are electrostatically charged and bond together as sand-sized aggregates. Laboratory simulations of wind abrasion involving aggregates show that at impact velocities capable of destroying sand, aggregates from a protective veneer on the target surface and can give rise to extremely low abrasion rates.

  12. Forecasting of operational indicators of grinding tools with the controlled form and orientation of abrasive grains

    NASA Astrophysics Data System (ADS)

    Korotkov, V. A.; Minkin, E. M.

    2015-09-01

    The interconnection of the abrasive grain front angle parameter with the form, orientation and wear out parameters is investigated. The form of the abrasive grains was estimated by means of form coefficient which represents the relation of diameters of the spheres described around contours of grains, to diameters of the spheres entered in them. The spatial orientation angle of the abrasive grains was defined between main (i.e. the biggest) axis of the grains and the cutting plane. It is established that, depending on an orientation angle at increase in a form coefficient of the abrasive grains can be either an increase or a decrease in the values of their front angles. In most cases, with an increase in a form coefficient of the oriented grinding grains (at orientation angles Θ=10°÷125°) the growth of their front angles is fixed. At tangential orientation of grains (Θ=0°) and at the close directions of orientation (Θ=135°÷80°) the return picture is observed. Also established that the longer the abrasive grain wears along the main axis and located in the tool body, the larger is its front angle. Besides that, the front angles of the abrasive grains reach the maximum positive values at orientation angles Θ=22.5°÷45°.Dependence of tension in grains during the work with parameters of their form, orientation and depth of embedment in the bundle is investigated. It was found that for all orientation angles of grains their tension significantly increases with an increase in their form coefficient. Besides that it is confirmed that the deeper the grain is in the bundle, the lower the tension is there. Also found that tension is minimal when the grains are tangential orientated. Further on increase the option of the grains in the direction of action of the cutting force follows. Such option of orientation is the most rational both from the point of view of minimization of tension, and for ensuring rational sizes of front angles of the abrasive grains. The

  13. High Pressure Water Jet System Performance Assessment Project A-2A

    SciTech Connect

    FARWICK, C.C.

    1999-12-03

    Performance assessment for canister cleaning system in the KE Basin. Information obtained from this assessment will be used to design any additional equipment used to clean canisters. After thorough review of the design, maintenance history and operational characteristics of the 105 K East (KE) canister cleaning system, Bartlett recommends that the high pressure water jet system (HPWJS) be modified as outlined in section 5.0, and retained for future use. Further, it is recommended that Spent Nuclear Fuel (SNF) Project consider use of a graded approach for canister cleaning, based on individual canister type and characteristics. This approach would allow a simple method to be used on canisters not needing the more rigorous, high-pressure method. Justification is provided in section 5.0. Although Bartlett has provided some preliminary cost estimates, it is recommended that SNF Project perform a detailed cost-benefit analysis to weigh the alternatives presented.

  14. Electron-Impact Water-Jet Microfocus Source for Water-Window Microscopy

    SciTech Connect

    Skoglund, P.; Lundstroem, U.; Vogt, U.; Takman, P.; Hertz, H. M.

    2011-09-09

    We demonstrate high-brightness operation of an electron-impact water-jet-anode soft x-ray source with an increased power loading of 15 times compared to our previously published results, with a corresponding increase in {approx}525-eV x-ray intensity of 6.4 times. This has been accomplished by improving the vacuum pumping system and the electron focusing optics, and increasing the liquid-jet velocity. The source now operates up to 120-W e-beam power and at a 525-eV brightness of 3.5x10{sup 9} ph/(sx{mu}m{sup 2}xsrxline). The source concept has potential to increase the x-ray brightness by another order of magnitude by optimizing the e-beam focusing and upgrading the power supply. Currently, spot enlargement with increased power is determined to be the most important limiting factor.

  15. OH Radical and a Drizzling Water Jet Production from the Ball-Lightning Discharge in Water

    NASA Astrophysics Data System (ADS)

    Maeyama, Mitsuaki; Tanaka, Yasutomo

    The ball lightning, or fireball discharge using the typical electrode configuration was reported to produce a long-living spherical plasmoid with radius exceed 10 cm at atmospheric pressure. In this study, we investigated the relationship between a optical output emitted from OH radicals and discharge conditions of the ball-lightning electrode configuration, and discussed its possibility to the water treatment process. As a results, in both polarity cases of the charged voltage V0, a ball-lightning discharge and the optical emission from OH radicals as a major radiation can be generated on the condition |V0| > 4 kV in tap water. Furthermore, an intensive upward water jet from the rod electrode is observed in case of positive polarity and in 0.2% NaCl solution, which is composed of drizzling water drops near the rod electrode.

  16. Computational fluid dynamics (CFD) in the design of a water-jet-drive system

    NASA Technical Reports Server (NTRS)

    Garcia, Roberto

    1994-01-01

    NASA/Marshall Space Flight Center (MSFC) has an ongoing effort to transfer to industry the technologies developed at MSFC for rocket propulsion systems. The Technology Utilization (TU) Office at MSFC promotes these efforts and accepts requests for assistance from industry. One such solicitation involves a request from North American Marine Jet, Inc. (NAMJ) for assistance in the design of a water-jet-drive system to fill a gap in NAMJ's product line. NAMJ provided MSFC with a baseline axial flow impeller design as well as the relevant working parameters (rpm, flow rate, etc.). This baseline design was analyzed using CFD, and significant deficiencies identified. Four additional analyses were performed involving MSFC changes to the geometric and operational parameters of the baseline case. Subsequently, the impeller was redesigned by NAMJ and analyzed by MSFC. This new configuration performs significantly better than the baseline design. Similar cooperative activities are planned for the design of the jet-drive inlet.

  17. Resistance of cyanobacterial fouling on architectural paint films to cleaning by water jet.

    PubMed

    Shirakawa, Marcia Aiko; Loh, Kai; John, Vanderley Moacir; Gaylarde, Christine Claire

    2012-04-01

    Mortar panels painted with three different white acrylic coatings were exposed to the environment in urban (São Paulo) and rural (Pirassununga) sites in Brazil for 7 years. After this time, all panels were almost equally discoloured, and paint detachment was observed to only a small degree. The biofilms were composed mainly of cyanobacteria and filamentous fungi, principal genera being Gloeocapsa and Chroococcidiopsis of the cyanobacteria, and Cladosporium and Alternaria of the fungi. Two of the three paints in Pirassununga became covered by a pink film that contained red-encapsulated Gloeocapsa and clay particles. The third, an 800% elastomeric matt formulation, became discoloured with a grey, only slightly pink, film, although the same cyanobacteria were present. The levels of paint detachments from all films in both locations were low, with rating range of 0-1 of a maximum 5 (100% detachment). After high-pressure water jetting, paint detachments increased at both locations, up to 2 in Pirassununga and 3 in São Paulo. Discoloration decreased; L*A*B* analysis of surface discoloration showed that ΔE (alteration in colour from the original paint film) changed from 28-39 before cleaning to 13-16 afterwards. The pink coloration was not entirely removed from Pirassununga samples, suggesting that cyanobacterial cells are difficult to detach, and microscopic analysis of the biofilms confirmed that Gloeocapsa was still present as the principal contaminant on all surfaces, with Chroococcidiopsis being present as the second most common. Almost no fungi were detected after water jet application. PMID:22215483

  18. Resistance of cyanobacterial fouling on architectural paint films to cleaning by water jet.

    PubMed

    Shirakawa, Marcia Aiko; Loh, Kai; John, Vanderley Moacir; Gaylarde, Christine Claire

    2012-04-01

    Mortar panels painted with three different white acrylic coatings were exposed to the environment in urban (São Paulo) and rural (Pirassununga) sites in Brazil for 7 years. After this time, all panels were almost equally discoloured, and paint detachment was observed to only a small degree. The biofilms were composed mainly of cyanobacteria and filamentous fungi, principal genera being Gloeocapsa and Chroococcidiopsis of the cyanobacteria, and Cladosporium and Alternaria of the fungi. Two of the three paints in Pirassununga became covered by a pink film that contained red-encapsulated Gloeocapsa and clay particles. The third, an 800% elastomeric matt formulation, became discoloured with a grey, only slightly pink, film, although the same cyanobacteria were present. The levels of paint detachments from all films in both locations were low, with rating range of 0-1 of a maximum 5 (100% detachment). After high-pressure water jetting, paint detachments increased at both locations, up to 2 in Pirassununga and 3 in São Paulo. Discoloration decreased; L*A*B* analysis of surface discoloration showed that ΔE (alteration in colour from the original paint film) changed from 28-39 before cleaning to 13-16 afterwards. The pink coloration was not entirely removed from Pirassununga samples, suggesting that cyanobacterial cells are difficult to detach, and microscopic analysis of the biofilms confirmed that Gloeocapsa was still present as the principal contaminant on all surfaces, with Chroococcidiopsis being present as the second most common. Almost no fungi were detected after water jet application.

  19. Abrasion resistance of medical glove materials.

    PubMed

    Walsh, Donna L; Schwerin, Matthew R; Kisielewski, Richard W; Kotz, Richard M; Chaput, Maria P; Varney, George W; To, Theresa M

    2004-01-15

    Due to the increasing demand for nonlatex medical gloves in the health-care community, there is a need to assess the durability of alternative glove materials. This study examines durability characteristics of various glove materials by abrasion resistance testing. Natural rubber latex (latex), polyvinyl chloride (vinyl), acrylonitrile butadiene (nitrile), polychloroprene (neoprene), and a styrene-ethylene/butylene-styrene block copolymer (SEBS) were tested. All test specimens, with the exception of the vinyl, were obtained from surgical gloves. Unaged out-of-the-box specimens as well as those subjected to various degrees of artificial aging were included in the study. After the abrasion sequence, the barrier integrity of the material was assessed through the use of a static leak test. Other traditional tests performed on these materials were viral penetration to validate the abrasion data and tear testing for comparative purposes. The results indicate that specific glove-material performance is dependent upon the particular test under consideration. Most notably, abrasion, even in controlled nonsevere conditions, may compromise to varying degrees the barrier integrity of latex, vinyl, SEBS, nitrile, and neoprene glove materials. However, as evidenced by the results of testing three brands of neoprene gloves, the abrasion resistance of any one glove material may be significantly affected by variations in production processes. PMID:14689500

  20. An investigation into magnetic electrolytic abrasive turning

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  1. Friction and abrasion of elastomeric materials

    NASA Technical Reports Server (NTRS)

    Gent, A. N.

    1975-01-01

    An abrasion apparatus is described. Experimental measurements are reported for four representative elastomeric materials, including a typical high-quality tire tread material and a possible replacement material for aircraft tire treads based on transpolypentenamer (TPPR). Measurements are carried out at different levels of frictional work input, corresponding to different severities of wear, and at both ambient temperature and at 100 C. Results indicate the marked superiority in abrasion resistance of the material based on TPPR, especially at 100 C, in comparison with the other materials examined.

  2. Effect of Different Cutting Techniques on the Surface Morphology and Composition of Niobium

    SciTech Connect

    Cooper, C.A.; Wu, A.; Bauer, P.; Antoine, C.; /Fermilab

    2009-01-01

    The surface morphology and chemical purity of superconducting radio frequency (SRF) niobium cavities are very important for proper accelerator operation. Typically on the order of 120 micrometers of niobium (Nb) is removed from cavities to remove damage done during the forming of Nb sheets and cavities. A study was done to find the effect of cutting or finishing Nb with a band saw, diamond saw, electrical discharge machining (EDM) wire, garnet water jet, sheer, and mill. Surface contamination of the samples was measured before and after buffered chemical polish (BCP) by secondary ion mass spectroscopy (SIMS), energy dispersive spectroscopy (EDS), and by measuring relative resistivity ratios (RRRs). Surface morphology was examined with a digital microscope, a surface profilometer and scanning electron microscope (SEM). It was found that all techniques altered the top 3-5 micrometers of the Nb. It was also found by SIMS that the water jet technique introduced the most hydrogen and oxygen to the Nb in the first 2.5 micrometers of the sample. The EDM wire cutting technique introduced the least amount of hydrogen to the Nb. After 5 micrometers were etched away by BCP on the various samples, no contaminants were found except on the water jet cut samples. Even after 20 micrometers of Nb removal silica could be seen on the surface with EDS. The water jet produced the roughest surface with 50-100 micrometer deep pits made from embedded garnet particles. It was found that the garnet water jet damages the surface to the point where even the typical 120 micrometers of BCP etching may not remove all the defects created.

  3. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing... that contains an abrasive material, such as silica pumice, intended to remove debris from the...

  4. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing... that contains an abrasive material, such as silica pumice, intended to remove debris from the...

  5. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing... that contains an abrasive material, such as silica pumice, intended to remove debris from the...

  6. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... exceeded. (j) All employees using abrasive wheels shall be protected by eye protection equipment in accordance with the requirements of subpart I of this part except when adequate eye protection is afforded by eye shields which are permanently attached to the bench or floor stand....

  7. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  8. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  9. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  10. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  11. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  12. 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...

  13. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  15. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abrasive device and accessories. 872.6010 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a) Identification. An abrasive device and accessories is a device constructed of various...

  16. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Abrasive device and accessories. 872.6010 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a) Identification. An abrasive device and accessories is a device constructed of various...

  17. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  18. Experimental Study and CFD modeling of high speed water jets in air

    NASA Astrophysics Data System (ADS)

    Guha, Anirban; Barron, R. M.; Balachandar, R.

    2007-11-01

    High speed turbulent water jets are extensively used in industrial cleaning applications. They interact vigorously with the surrounding air and loose mass in the form of water droplets which moves along with the entrained air stream. The transfer of momentum to the surroundings reduces the jet velocity and thus the pressure at the impinging surface is significantly lower than the supply pressure. Laser Doppler Anemometer (LDA) measurements of velocity field and pressure measurements at different axial and radial locations were performed. The potential core of the jet was found to extend to around 100 nozzle diameters. The dynamic pressure along the centerline was found to decay linearly, which can be used to estimate the decay of water volume fraction along the centerline. An empirical formulation of mass transfer (in the form of droplets) from water phase to the surroundings has been developed and incorporated into the commercial CFD code FLUENT. The flow was simulated using the RNG k-ɛ turbulence model and Eulerian-Eulerian multiphase model. The predicted pressure distribution at the impinging surface was found to match closely with the experimental findings.

  19. Velocity Measurements of a Pistol Shrimp's Micro Water Jet Using High Speed PIV

    NASA Astrophysics Data System (ADS)

    Torres, J.; Washington, K.; Wong, S.; Zarzecki, M.; Cheng, Y.; Diez, F. J.

    2007-11-01

    The pistol shrimp generates a high speed micro water jet that was studied experimentally using time resolved particle image velocimetry. The pistol shrimp, with an average size of about 5.5 cm, is considered to be one of the loudest animals in the world. The sound generated can reach intensity levels as high as 200 db. In the past, it was believed that the loud noise was produced by the shrimp closing its claws. Recent research has revealed that the sound is actually generated by a bubble that is created when the claw is shut. The generated bubble is followed by a micro jet. This process is used by the shrimp to stunt and attack preys and to defend itself. In this cavitation process, the bubble is created by a sudden drop in pressure as the claw closes at speeds of 100 km/hr. The temperature inside the bubble can range from 5,000 to 10000 degrees Kelvin and generates infrared light. This whole process is estimated to last around 300 microseconds. The phenomenon of the bubble itself is believed to take at most 10 nanoseconds. This research focuses in visualizing the bubble and the micro jet produced during the closing of the claw and characterizing the velocity field generated by the micro jet by taking PIV images at a rate of up to 40,000 frames per second.

  20. Separation and reconstruction of high pressure water-jet reflective sound signal based on ICA

    NASA Astrophysics Data System (ADS)

    Yang, Hongtao; Sun, Yuling; Li, Meng; Zhang, Dongsu; Wu, Tianfeng

    2011-12-01

    The impact of high pressure water-jet on the different materials target will produce different reflective mixed sound. In order to reconstruct the reflective sound signals distribution on the linear detecting line accurately and to separate the environment noise effectively, the mixed sound signals acquired by linear mike array were processed by ICA. The basic principle of ICA and algorithm of FASTICA were described in detail. The emulation experiment was designed. The environment noise signal was simulated by using band-limited white noise and the reflective sound signal was simulated by using pulse signal. The reflective sound signal attenuation produced by the different distance transmission was simulated by weighting the sound signal with different contingencies. The mixed sound signals acquired by linear mike array were synthesized by using the above simulated signals and were whitened and separated by ICA. The final results verified that the environment noise separation and the reconstruction of the detecting-line sound distribution can be realized effectively.

  1. Hazardous waste retrieval strategies using a high-pressure water jet scarifier

    SciTech Connect

    Hatchell, B.K.; Rinker, M.W.; Mullen, O.D.

    1995-08-01

    The Waste Dislodging and Conveyance Program is sponsored by the US Department of Energy Office of Technology Development to investigate waste dislodging and conveyance processes suitable for the retrieval of high-level radioactive waste. This program, represented by industry, national laboratories, and academia, has proposed a baseline technology of high-pressure water jet dislodging and pneumatic conveyance integrated as a scarifier as a means of retrieval of waste inside Hanford single-shell tanks. A testing program has been initiated to investigate system deployment techniques to determine appropriate mining strategies, level of control, sensor requirements, and address integration issues associated with deploying the scarifier by a long robotic manipulator arm. A test facility denoted the Hydraulics Testbed (HTB) is being constructed to achieve these objectives and to allow longer-duration, multiple-pass tests on large waste fields using a versatile gantry-style manipulator. Mining strategy tests with materials simulating salt cake and sludge waste forms will be conducted to evaluate the effectiveness of mining strategies, forces related to scarifier and conveyance line, and retrieval rate. This paper will describe the testbed facility and testing program and present initial test results to date.

  2. The development of an in vitro test method for predicting the abrasion resistance of textile and metal components of endovascular stent grafts.

    PubMed

    Yao, Tong; Choules, Brian D; Rust, Jon P; King, Martin W

    2014-04-01

    Implantable endovascular stent grafts have become a frequent option for the treatment of abdominal and thoracic aneurysms. Given that such devices are permanent implants, the question of long-term biostability needs to be addressed. This article describes the development of an in vitro stent graft abrasion test method between the graft fabric and metal stent of an endovascular device. Three endpoints were established to determine the abrasion resistance between the fabric and stent surfaces after a predetermined number of abrasion cycles. During initial testing, two types of graft fabric materials, multifilament woven polyester fabric and monofilament woven polyester fabric, and two types of stent materials, laser cut nitinol stents and regular nitinol stent wire, were evaluated under dry and wet conditions. The results have shown that this test method is viable for testing the relative abrasion resistance of the components of endovascular stent grafts. The abrasion resistance of both fabrics was lower in a wet environment compared to being tested dry. Additionally, the multifilament polyester fabric had better abrasion resistance than the monofilament polyester fabric. The laser cut nitinol stent was more aggressive in creating holes and breaking yarns, while the regular nitinol stent wire caused a greater loss in fabric strength.

  3. The development of an in vitro test method for predicting the abrasion resistance of textile and metal components of endovascular stent grafts.

    PubMed

    Yao, Tong; Choules, Brian D; Rust, Jon P; King, Martin W

    2014-04-01

    Implantable endovascular stent grafts have become a frequent option for the treatment of abdominal and thoracic aneurysms. Given that such devices are permanent implants, the question of long-term biostability needs to be addressed. This article describes the development of an in vitro stent graft abrasion test method between the graft fabric and metal stent of an endovascular device. Three endpoints were established to determine the abrasion resistance between the fabric and stent surfaces after a predetermined number of abrasion cycles. During initial testing, two types of graft fabric materials, multifilament woven polyester fabric and monofilament woven polyester fabric, and two types of stent materials, laser cut nitinol stents and regular nitinol stent wire, were evaluated under dry and wet conditions. The results have shown that this test method is viable for testing the relative abrasion resistance of the components of endovascular stent grafts. The abrasion resistance of both fabrics was lower in a wet environment compared to being tested dry. Additionally, the multifilament polyester fabric had better abrasion resistance than the monofilament polyester fabric. The laser cut nitinol stent was more aggressive in creating holes and breaking yarns, while the regular nitinol stent wire caused a greater loss in fabric strength. PMID:24115449

  4. Wheel Abrasion Experiment Conducted on Mars

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    1998-01-01

    Sojourner rover showing Lewis' wheel abrasion experiment. The Mars Pathfinder spacecraft soft-landed on Mars on July 4, 1997. Among the many experiments on its small Sojourner rover are three technology experiments from the NASA Lewis Research Center, including the Wheel Abrasion Experiment (WAE). The WAE was designed, built, delivered, and operated on Mars by a team of engineers and scientists from Lewis' Photovoltaics and Space Environments Branch. This experiment collected data to assess wheel surface wear on the Sojourner. It used a specially designed rover wheel, with thin films (200 to 1000 angstroms) of aluminum, nickel, and platinum deposited on black, anodized aluminum strips attached to the rover's right center wheel. As the wheel spun in the Martian soil, a photovoltaic sensor monitored changes in film reflectivity. These changes indicated abrasion of the metal films by Martian surface material. Rolling wear data were accumulated by the WAE. Also, at frequent intervals, all the rover wheels, except the WAE test wheel, were locked to hold the rover stationary while the test wheel alone was spun and dug into the Martian regolith. These tests created wear conditions more severe than simple rolling. The WAE will contribute substantially to our knowledge of Martian surface characteristics. Marked abrasion would indicate a surface composed of hard, possibly sharply edged grains, whereas lack of abrasion would suggest a somewhat softer surface. WAE results will be correlated with ground simulations to determine which terrestrial materials behave most like those on Mars. This knowledge will enable a deeper understanding of erosion processes on Mars and the role they play in Martian surface evolution. Preliminary results show that electrostatic charging of the rover wheels sometimes caused dust to accumulate on the WAE wheel, making interpretation of the reflectance data problematic. If electrostatic charging is the mechanism for dust attraction, this indicates

  5. Break-up and atomization of a round water jet by a high-speed annular air jet

    NASA Astrophysics Data System (ADS)

    Lasheras, J. C.; Villermaux, E.; Hopfinger, E. J.

    1998-02-01

    The near- and far-field break-up and atomization of a water jet by a high-speed annular air jet are examined by means of high-speed flow visualizations and phase Doppler particle sizing techniques. Visualization of the jet's near field and measurements of the frequencies associated with the gas liquid interfacial instabilities are used to study the underlying physical mechanisms involved in the primary break-up of the water jet. This process is shown to consist of the stripping of water sheets, or ligaments, which subsequently break into smaller lumps or drops. An entrainment model of the near-field stripping of the liquid is proposed, and shown to describe the measured liquid shedding frequencies. This simplified model explains qualitatively the dependence of the shedding frequency on the air/water momentum ratio in both initially laminar and turbulent water jets. The role of the secondary liquid break-up in the far-field atomization of the water jet is also investigated, and an attempt is made to apply the classical concepts of local isotropy to explain qualitatively the measurement of the far-field droplet size distribution and its dependence on the water to air mass and momentum ratios. Models accounting for the effect of the local turbulent dissipation rate in the gas on both the break-up and coalescence of the droplets are developed and compared with the measurements of the variation of the droplet size along the jet's centreline. The total flux of kinetic energy supplied by the gas per unit total mass of the spray jet was found to be the primary parameter determining the secondary break-up and coalescence of the droplets in the far field.

  6. Kerf modelling in abrasive waterjet milling using evolutionary computation and ANOVA techniques

    NASA Astrophysics Data System (ADS)

    Alberdi, A.; Rivero, A.; Carrascal, A.; Lamikiz, A.

    2012-04-01

    Many researchers demonstrated the capability of Abrasive Waterjet (AWJ) technology for precision milling operations. However, the concurrence of several input parameters along with the stochastic nature of this technology leads to a complex process control, which requires a work focused in process modelling. This research work introduces a model to predict the kerf shape in AWJ slot milling in Aluminium 7075-T651 in terms of four important process parameters: the pressure, the abrasive flow rate, the stand-off distance and the traverse feed rate. A hybrid evolutionary approach was employed for kerf shape modelling. This technique allowed characterizing the profile through two parameters: the maximum cutting depth and the full width at half maximum. On the other hand, based on ANOVA and regression techniques, these two parameters were also modelled as a function of process parameters. Combination of both models resulted in an adequate strategy to predict the kerf shape for different machining conditions.

  7. Abrasion-Resistant Technology and its Prospect for CFB Boilers

    NASA Astrophysics Data System (ADS)

    Zheng, H.; Li, Y. J.; Wang, L. J.; Liu, S. H.; Dou, Q. R.

    In recent years, CFB boilers (CFBB) have been widely used in the commercial power plants due to its environmental benefits, high combustion efficiency, wide coal flexibility, and some other advantages. At the same time, the abrasion problem, the greatest weakness of this kind of boiler, has been gradually exposed in its application process. The abrasion, particularly on key parts such as the heating surface of water-cooled wall, furnace corners, separator entrance, seriously restricts the long-period operation ability of the CFBB. This article discusses current development status for various abrasion resistant refractory materials used in a CFBB. Some comments are provided for developing new high-performance abrasion resistant refractory materials and rapid-repaired materials according to the abrasion principle and the abrasion on different parts, as well as the economical and environmental requirements for the material. The abrasion solution and operation period of CFBB can be better improved given realization.

  8. The effect of bleaching on toothbrush abrasion of resin composites

    PubMed Central

    Hajizadeh, Hila; Ameri, Hamideh; Eslami, Samaneh; Mirzaeepoor, Behnam

    2013-01-01

    Aim: This experimental study was designed to focus on the effects of bleaching on toothbrush abrasion in three types of composites with different filler size. Materials and Methods: Forty eight disks were prepared from three types of composite and divided into 6 groups. In the first three groups the abrasion test was done. The remaining groups were bleached and the abrasion test was performed. The weight of the samples before and after abrasion was measured. Statistical analysis was done with one-way ANOVA and Duncan test. Results: There was a significant difference in abrasion of composites with different filler size (P < 0.05). The most amount of abrasion was observed in Z100 after being bleached. An increase in abrasion was noticed in all three types of tested composite after bleaching. Conclusion: According to the findings, it is suggested to use a nano filled resin composite for restoration if the bleaching treatment is required. PMID:23349570

  9. Abrasion resistance of linings in filament wound composite pipe

    SciTech Connect

    Hall, S.C.

    1999-07-01

    Fiberglass filament wound composite pipe has numerous industrial applications including transportation of petroleum and natural gas. Its corrosion resistance is well known but it can be susceptible to abrasion and erosion when it is used to transport slurries or dry gas containing sand particles. However, composite pipe can be manufactured integrally with abrasion resistant linings which protect the pipe from abrasion and erosion and increase its life. Laboratory investigations were performed to determine the effect of abrasive flows through polyurea-lined and unlined glass-reinforced epoxy (GRE) pipe, ultra-high molecular weight (UHMW) polyethylene (PE) pipe, and unlined steel pipe. Results are provided for the abrasion resistance, chemical resistance, adhesion strength, elongation, tensile strength, impact resistance and hardness of selected linings. The abrasion resistance of polyurea-lined composite pipe proved to be almost as resistant to abrasion and erosion as unlined steel pipe without the electrochemical corrosion associated with steel pipe.

  10. Quantitative Imaging of Young's Modulus of Soft Tissues from Ultrasound Water Jet Indentation: A Finite Element Study

    PubMed Central

    Lu, Min-Hua; Mao, Rui; Lu, Yin; Liu, Zheng; Wang, Tian-Fu; Chen, Si-Ping

    2012-01-01

    Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%. PMID:22927890

  11. Cutting assembly

    DOEpatents

    Racki, Daniel J.; Swenson, Clark E.; Bencloski, William A.; Wineman, Arthur L.

    1984-01-01

    A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

  12. The role of the microfissuration of the rock matrix in the abrasion resistance of ornamental granitic rocks

    NASA Astrophysics Data System (ADS)

    Rodríguez-Rey, Angel; Sanchez-Delgado, Nuria; Camino, Clara; Calleja, Lope; Ruiz de Argandoña, Vicente G.; Setien, Alexia

    2015-04-01

    The microcrack density and the abrasion resistance of five ornamental granites (Albero, Gris Alba, Mondariz, Rosa Porriño and Traspieles) from Galicia (NW Spain) have been quantified as part of a research aimed to interpret the cuttability of the rocks in relation to the petrophysical properties of the rock matrix. Large blocks from the quarries have been cut with an industrial saw and the microcrack density and the abrasion resistance have been measured in two surfaces: H, parallel to the cut surface; T, perpendicular both to the cut surface and the cutting direction. Both planes are perpendicular to the rift plane, as it is known in quarry works. The microcrack density has been quantified following an stereological procedure applied to polished sections imaged under scanning electron microscopy. The magnification of the images allowed the study of microcracks as narrow as 2 microns in aperture. The density has been quantified in terms of length of microcrack traces per surface unit so possible anisotropies of the microcrack network could be detected. The obtained values are in the typical range for this type of rocks although the Traspieles granite shows a higher value due to its weathering degree (H: 5.11, T: 5.37 mm/mm2). The values measured in the two surfaces (H and T) are quite similar in four of the rocks; only the Albero granite shows a marked anisotropy (H: 2.76 T: 3.53 mm/mm2). The abrasion resistance of the rocks has been measured following the european standard EN 14157:2004 using the capon method. The rocks can be classified in two groups according to their abrasion resistance. Rosa Porriño, Gris Alba and Mondariz granites are the more resistant to abrasion with values around 16-17 mm. Albero and Traspieles granites are less resistant with values higher than 19 mm. The results show a good correlation between the microcrack density and the abrasion resistance. As can be expected the rocks with high microcrack density show low abrasion resistance. The

  13. A novel approach to abrasion resistance

    SciTech Connect

    Steele, W.A.; Mohr, P.B.; Leider, H.R.; Hirschfeld, T.B.

    1988-03-01

    The high abrasion and impact loads characteristic of many technologies require frequent maintenance or special materials. Conventional approaches to protection have used either extremely hard coatings or complaint elastomeric coatings. The former are typically ceramic or ceramic-like surfaces produced by direct deposition or by in situ formation by oxidation, carburization or nitriding. Ceramic coatings are very good against abrasion, but are vulnerable to impact damage. Elastomeric coatings have excellent impact resistance and are capable of withstanding deformation; however, they are limited in thermal range and chemical resistance. It is possible to combine the desirable properties of both types by using ''hair,'' a structure in which an extremely hard material can be simultaneously elastic and compliant by virture of a very high L/D ratio. We have demonstrated the good performance of carbon fiber ''hair'' in resisting damage from impacting particles and have identified a probable failure mechanism. 7 refs., 6 figs., 1 tab.

  14. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  15. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, E.L.

    1984-11-29

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

  16. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, Edward L.

    1985-01-01

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

  17. Cutting Candles

    ERIC Educational Resources Information Center

    Ranucci, Ernest R.

    1973-01-01

    Different regular-polygon-shaped candles wound with a sheet of paper are cut through obliquely. When the papers are unwound, unique patterns are revealed. Investigation of these patterns leads to the discovery of geometric concepts. (JP)

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

    SciTech Connect

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

    2012-02-01

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

  19. Long-Term Stability of Residual Stress Improvement by Water Jet Peening Considering Working Processes.

    PubMed

    Hashimoto, Tadafumi; Osawa, Yusuke; Itoh, Shinsuke; Mochizuki, Masahito; Nishimoto, Kazutoshi

    2013-06-01

    To prevent primary water stress corrosion cracking (PWSCC), water jet peening (WJP) has been used on the welds of Ni-based alloys in pressurized water reactors (PWRs). Before WJP, the welds are machined and buffed in order to conduct a penetrant test (PT) to verify the weld qualities to access, and microstructure evolution takes place in the target area due to the severe plastic deformation. The compressive residual stresses induced by WJP might be unstable under elevated temperatures because of the high dislocation density in the compressive stress layer. Therefore, the stability of the compressive residual stresses caused by WJP was investigated during long-term operation by considering the microstructure evolution due to the working processes. The following conclusions were made: The compressive residual stresses were slightly relaxed in the surface layers of the thermally aged specimens. There were no differences in the magnitude of the relaxation based on temperature or time. The compressive residual stresses induced by WJP were confirmed to remain stable under elevated temperatures. The stress relaxation at the surface followed the Johnson-Mehl equation, which states that stress relaxation can occur due to the recovery of severe plastic strain, since the estimated activation energy agrees very well with the self-diffusion energy for Ni. By utilizing the additivity rule, it was indicated that stress relaxation due to recovery is completed during the startup process. It was proposed that the long-term stability of WJP under elevated temperatures must be assessed based on compressive stresses with respect to the yield stress. Thermal elastic-plastic creep analysis was performed to predict the effect of creep strain. After 100 yr of simulated continuous operation at 80% capacity, there was little change in the WJP compressive stresses under an actual operating temperature of 623 K. Therefore, the long-term stability of WJP during actual operation was

  20. Experimental Application of Piezoelectric Actuator-Driven Pulsed Water Jets in Retinal Vascular Surgery

    PubMed Central

    Kunikata, Hiroshi; Tanaka, Yuji; Aizawa, Naoko; Nakagawa, Atsuhiro; Tominaga, Teiji; Nakazawa, Toru

    2014-01-01

    Purpose To report on the effectiveness and safety of an ophthalmic piezoelectric actuator-driven pulsed water jet (ADPJ) system adapted for intraocular use. Methods First, we determined the highest ADPJ flow rate that did not cause an unsafe rise in intraoperative intraocular pressure (IOP) in rabbits (n = 4). Next, we determined the most effective ADPJ frequency (in hertz) at that flow rate. Finally, we visualized the ADPJ stream, measured its pressure, and determined the minimum voltage and distance between the ADPJ needle and retinal veins to induce intravenous displacement of the blood column (DBC) through massage of the outer retinal vessels (n = 3) while not causing retinal tearing or hemorrhage. Results We found that a 0.05 mL/min ADPJ flow rate caused IOP to rise above 40 mm Hg after 1 minute, but that at 0.025 mL/min, IOP stayed below 40 mm Hg even after 3 minutes. Moreover, we found that a 0.025 mL/min ADPJ stream was stable at a pulse frequency of 10 Hz and that at this flow rate/frequency the ADPJ pressure was closely correlated with the applied voltage (P < 0.001, r2 = 0.9991). The minimum voltage and distance to achieve intravenous DBC without causing retinal tearing or hemorrhage were 40 V and 0.5 mm, respectively. Conclusions With an appropriate flow rate and surgical time, ADPJ successfully induced massage of the retinal vessels and intravenous DBC while maintaining safe IOP and not causing retinal complications. Translational Relevance The ADPJ system has promise as a safe and minimally invasive instrument for the intraocular surgical treatment of human retinal vascular diseases. PMID:25674359

  1. Adipose Mesenchymal Stem Cells Isolated after Manual or Water-jet-Assisted Liposuction Display Similar Properties

    PubMed Central

    Bony, Claire; Cren, Mailys; Domergue, Sophie; Toupet, Karine; Jorgensen, Christian; Noël, Danièle

    2016-01-01

    Mesenchymal stem or stromal cells (MSC) are under investigation in many clinical trials for their therapeutic potential in a variety of diseases, including autoimmune and inflammatory disorders. One of the main sources of MSCs is the adipose tissue, which is mainly obtained by manual liposuction using a cannula linked to a syringe. However, in the past years, a number of devices for fat liposuction intended for clinical use have been commercialized but few papers have compared these procedures in terms of stromal vascular fraction (SVF) or adipose mesenchymal stromal cells (ASC). The objective of the present study was to compare and qualify for clinical use the ASC obtained from fat isolated with the manual or the Bodyjet® water-jet-assisted procedure. Although the initial number of cells obtained after collagenase digestion was higher with the manual procedure, the percentage of dead cells, the number of colony forming unit-fibroblast and the phenotype of cells were identical in the SVF at isolation (day 0) and in the ASC populations at day 14. We also showed that the osteogenic and adipogenic differentiation potentials of ASCs were identical between preparations while a slight but significant higher in vitro immunosuppressive effect was observed with ASCs isolated from fat removed with a cannula. The difference in the immunomodulatory effect between ASC populations was, however, not observed in vivo using the delayed-type hypersensitivity (DTH) model. Our data, therefore, indicate that the procedure for fat liposuction does not impact the characteristics or the therapeutic function of ASCs. PMID:26834736

  2. Development of a fixed abrasive slicing technique (FAST) for reducing the cost of photovoltaic wafers

    SciTech Connect

    Schmid, F. )

    1991-12-01

    This report examines a wafer slicing technique developed by Crystal Systems, Inc. that reduces the cost of photovoltaic wafers. This fixed, abrasive slicing technique (FAST) uses a multiwire bladepack and a diamond-plated wirepack; water is the coolant. FAST is in the prototype production stage and reduces expendable material costs while retaining the advantages of a multiwire slurry technique. The cost analysis revealed that costs can be decreased by making more cuts per bladepack and slicing more wafers per linear inch. Researchers studied the degradation of bladepacks and increased wirepack life. 21 refs.

  3. A new dimension to conservative dentistry: Air abrasion

    PubMed Central

    Hegde, Vivek S; Khatavkar, Roheet A

    2010-01-01

    Air abrasion dentistry has evolved over a period of time from a new concept of an alternative means of cavity preparation to an essential means of providing a truly conservative preparation for preservation of a maximal sound tooth structure. The development of bonded restorations in combination with air abrasion dentistry provides a truly minimal intervention dentistry. This article reviews the development of air abrasion, its clinical uses, and the essential accessories required for its use. PMID:20582212

  4. Low stress abrasive wear behavior of a hardfaced steel

    NASA Astrophysics Data System (ADS)

    Dasgupta, R.; Prasad, B. K.; Jha, A. K.; Modi, O. P.; Das, S.; Yegneswaran, A. H.

    1998-04-01

    A plain carbon steel was overlayed with a wear-resistant hardfacing alloy by manual arc welding. Low stress abrasive wear tests were conducted with an ASTM rubber wheel abrasion tester using crushed silica and as the abrasive medium. The wear rate decreased with sliding distance, and there was an overall improvement in the abrasive wear resistance as a result of overlaying. The wear behavior of the samples has been discussed in terms of microstructural features while the examination of wear surface and subsurface regions provides insight into the wear mechanisms.

  5. Study on ultra-precision magnetic abrasive finishing process using low frequency alternating magnetic field

    NASA Astrophysics Data System (ADS)

    Wu, Jinzhong; Zou, Yanhua; Sugiyama, Hitoshi

    2015-07-01

    We proposed a new ultra-precision magnetic abrasive finishing (MAF) process using low frequency alternating magnetic field in this paper. Magnetic cluster themselves may produce the up and down movement change under alternating magnetic force. The movement may not only promote the dispersion of micro-magnetic particles, but also improve stirring effect and cross-cutting effects of the abrasives, achieving circulation and update to ensure the stability of grinding tools. This process is considered to be able to efficiently apply in ultra-precision finishing of plane and complicated micro-surfaces. In this study, we investigated the effects of alternating magnetic field on magnetic field distribution, finishing force and abrasive behavior. Furthermore, a set of experimental devices have been designed for finishing SUS304 stainless steel plate. The present work is aimed at understanding finishing particularity of this process and studying impacts of important process parameters namely grinding fluid, rotational speed of magnetic pole, current frequency on change in finish surface and material removal. Experimental results indicate that the process can realize ultra-precision finishing of plane by using oily grinding fluid. In the present research, the surface roughness of SUS304 stainless steel plate was improved from 240.24 nm to 4.38 nm by this process.

  6. A comparative study of the abrasive wear behavior of MoSi[sub 2

    SciTech Connect

    Hawk, J.A.; Alman, D.E. . Albany Research Center)

    1995-03-01

    This study is a preliminary assessment of the abrasive wear behavior of monolithic MoSi[sub 2]. Comparisons with the wear behavior of other advanced materials, such as refractory metals, intermetallic compounds (i.e., TiAl, Fe[sub 3]Al), and ceramics (i.e., Si[sub 3]N[sub 4], ZrO[sub 2], and Al[sub 2]O[sub 3]), are made. In general, the wear behavior of MoSi[sub 2] is similar to oxide ceramics, due in large part to the high relative hardness of the compound. However, as with most brittle materials, as the hardness of the abrasive increases relative to the hardness of the wearing material (i.e., MoSi[sub 2] abraded on garnet at 13 GPa versus abrasion on SiC at 24 GPa), volume wear increases; and the dominant wear mechanism changes, from one of primarily edge fracture to one combining micro-cutting with significant micro-fracture and grain pull-out.

  7. Mars Pathfinder Wheel Abrasion Experiment Ground Test

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  8. Abrasive Wear Resistance of Tool Steels Evaluated by the Pin-on-Disc Testing

    NASA Astrophysics Data System (ADS)

    Bressan, José Divo; Schopf, Roberto Alexandre

    2011-05-01

    Present work examines tool steels abrasion wear resistance and the abrasion mechanisms which are one main contributor to failure of tooling in metal forming industry. Tooling used in cutting and metal forming processes without lubrication fails due to this type of wear. In the workshop and engineering practice, it is common to relate wear resistance as function of material hardness only. However, there are others parameters which influences wear such as: fracture toughness, type of crystalline structure and the occurrence of hard precipitate in the metallic matrix and also its nature. In the present investigation, the wear mechanisms acting in tool steels were analyzed and, by normalized tests, wear resistance performance of nine different types of tool steels were evaluated by pin-on-disc testing. Conventional tool steels commonly used in tooling such as AISI H13 and AISI A2 were compared in relation to tool steels fabricated by sintering process such as Crucible CPM 3V, CPM 9V and M4 steels. Friction and wear testing were carried out in a pin-on-disc automated equipment which pin was tool steel and the counter-face was a abrasive disc of silicon carbide. Normal load of 5 N, sliding velocity of 0.45 m/s, total sliding distance of 3000 m and room temperature were employed. The wear rate was calculated by the Archard's equation and from the plotted graphs of pin cumulated volume loss versus sliding distance. Specimens were appropriately heat treated by quenching and three tempering cycles. Percentage of alloying elements, metallographic analyses of microstructure and Vickers microhardness of specimens were performed, analyzed and correlated with wear rate. The work is concluded by the presentation of a rank of tool steel wear rate, comparing the different tool steel abrasion wear resistance: the best tool steel wear resistance evaluated was the Crucible CPM 9V steel.

  9. High pressure waterjet cutting industrial needs survey

    NASA Astrophysics Data System (ADS)

    Klavuhn, John; Baker, Bruce

    1989-08-01

    The results are presented of a survey conducted by personnel of the National Center for Excellence in Metalworking Technology (NCEMT) to assess the industrial needs in high pressure water jet cutting (WJC) technology. Survey forms were mailed to approximately 1400 individuals obtained from three mailing lists. The respondents included approximately 200 individuals associated with a variety of industries: 12 percent were WJC equipment suppliers, 40 percent were WJC users, and 48 percent were neither suppliers nor users. The survey addressed five specific areas of WJC technology: research and development, standards, systems, new products, and training and service. Results show that the need having the highest priority is the establishment of a database on WJC that contains the cutting parameters for a wide range of materials. Associated with this objective is the expressed need for an independent demonstration and test center for testing, data generation and operator training. A further need was found for establishing organized efforts in hardware development and research in mechanisms of cutting.

  10. Analysis of acoustic signals on welding and cutting

    SciTech Connect

    Morita, Takao; Ogawa, Yoji; Sumitomo, Takashi

    1995-12-31

    The sounds emitted during the welding and cutting processes are closely related to the processing phenomena, and sometimes they provide useful information for evaluation of their processing conditions. The analyses of acoustic signals from arc welding, plasma arc cutting, oxy-flame cutting, and water jet cutting are carried out in details in order to develop effective signal processing algorithm. The sound from TIG arc welding has the typical line spectrum which principal frequency, is almost the same as that of supplied electricity. The disturbance of welding process is clearly appeared oil the acoustic emission. The sound exposure level for CO{sub 2} or MIG welding is higher than that for TIG welding, and the relative intensity of the typical line spectrum caused by supplied electricity becomes low. But the sudden transition of welding condition oil produces an apparent change of sound exposure level. On the contrary, the acoustics from cutting processes are much louder than those of arc welding and show more chaotic behavior because the supplied fluid velocity and temperature of arc for cutting processes are much higher than those for welding processes. Therefore, it requires a special technique to extract the well meaning signals from the loud acoustic sounds. Further point of view, the reduction of acoustic exposure level becomes an important research theme with the growth of application fields of cutting processes.

  11. Feasibility study on welding and cutting methods for thick plate in fusion reactor

    SciTech Connect

    Osaki, T.; Nakayama, Y.; Kobayashi, T.

    1995-12-31

    Application of tungsten-arc inert-gas (TIG) welding with narrow gap has been considered as a hopeful joint method to suppress post welding deformation for thick plates. The authors studied some parameters to predict the post-welding deformation for the narrow gap shape of TIG welding. As for cutting methods, the water jet method was applied for weld joints in this study. Reweld tests by using the TIG welding method were successfully performed under the condition of cutting surface as it was. Results of tensile tests for reweld joints showed no reduction in strength. This reveals a good prospect of providing reweld groove surface without any machining on site.

  12. Performance of water jet cooled silicon monochromators in high power x-ray beams (abstract)

    NASA Astrophysics Data System (ADS)

    Berman, Lonny E.; Hart, Michael

    1992-01-01

    We have fabricated and tested water jet cooled silicon (111) and (220) monochromators specially tailored for extended wiggler beam and concentrated undulator beam power loadings. The tests were made at the X25 27 pole, 1.1 T hybrid wiggler beam line1 at the National Synchrotron Light Source (NSLS). The wiggler-like line-type loading was produced by the direct, unfocused wiggler white beam, in which 300 W of total power in a 60-mm-wide by 5-mm-high [full width at half maximum (FWHM)] cross section were available in the experimental hutch; this represents a typical power density at existing insertion device beam lines. The undulator-like point-type loading was produced by the focused wiggler white beam, generated via reflection of a portion of the direct white beam from a toroidal platinum-coated silicon mirror, resulting in 75 W of total power in a 0.8-mm-wide (FWHM) by 0.45-mm-high (FWHM) cross section in the hutch. This will be a typical power density at next-generation insertion device beam lines. The monochromator design consists of a thin walled silicon box whose bottom is glued to a stainless-steel water manifold; the coolant is delivered through jet tubes directed perpendicular to the underside of the top, diffracting surface of the box.2 Rectangular monochromators with multiple jets were used for the line power loading studies, and cylindrical monochromators with single jets were used for the point power loading studies. Provisions for simple adaptive corrections to compensate for the inevitable beam-induced thermal deformations, consisting of mechanisms to reverse-bend the top surface, and internal heat baffles to frustrate the cooling at the edges of the crystal (to produce an isothermal top surface), were included in the designs. These required approximate matching of the top surface dimensions to the x-ray footprint. To better understand the thermal strain fields, spatial and angular mapping of both fundamental and harmonic Bragg reflections within the

  13. Generation of ultra-fast cumulative water jets by sub-microsecond underwater electrical explosion of conical wire arrays

    SciTech Connect

    Shafer, D.; Gurovich, V. Tz.; Gleizer, S.; Gruzinsky, K.; Krasik, Ya. E.

    2015-12-15

    The results of experiments with underwater electrical explosion of modified conical arrays of copper and aluminum wires are presented. A pulsed generator producing a 550 kA-amplitude current with a 400 ns rise time was used in the explosion of the arrays. The array explosion generates water flows converging at the axis of the cone. This flow generates a fast-moving water jet with a velocity exceeding 1.8 × 10{sup 5 }cm/s, which was observed being ejected from the surface of the water covering the array. The positions of the water jet were measured by multiple-exposure fast framing imaging. In experiments, the apex angle of the array, the thickness of the water layer above the arrays, or the material of the wires was altered, which changed the resulting velocities and shapes of the emitted jets. A model that considers the converging stationary flow of a slightly compressible fluid is suggested. The velocities and shapes of the jets obtained by this model agree well with the experimentally measured jet velocities.

  14. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided with... omitted; and (ii) The spindle end, nut, and outer flange may be exposed on machines designed as...

  15. Microwave sintering of sol-gel derived abrasive grain

    DOEpatents

    Plovnick, Ross; Celikkaya, Ahmet; Blake, Rodger D.

    1997-01-01

    A method is provided for making microwave-sintered, free flowing alpha alumina-based ceramic abrasive grain, under conditions effective to couple microwaves with calcined alpha alumina-based abrasive gain precursor and sinter it at a temperature of at least about 1150.degree. C.

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

    PubMed Central

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

    2013-01-01

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

  17. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the... 29 Labor 8 2012-07-01 2012-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303...

  18. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the... 29 Labor 8 2013-07-01 2013-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303...

  19. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the... 29 Labor 8 2011-07-01 2011-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303...

  20. Soybean seedlings tolerate abrasion from air-propelled grit

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Design of an impact abrasion testing machine

    NASA Astrophysics Data System (ADS)

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

    1994-04-01

    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.

  2. Hydro-abrasive erosion: Problems and solutions

    NASA Astrophysics Data System (ADS)

    Winkler, K.

    2014-03-01

    The number of hydro power plants with hydro-abrasive erosion is increasing worldwide. An overall approach is needed to minimize the impact of this phenomenon. Already at the start of the planning phase an evaluation should be done to quantify the erosion and the impact on the operation. For this, the influencing parameters and their impact on the erosion have to be known. The necessary information for the evaluation comprises among others the future design, the particle parameters of the water, which will pass the turbine, and the power plant owner's framework for the future operation like availability or maximum allowable efficiency loss, before an overhaul needs to be done. Based on this evaluation of the erosion, an optimised solution can then be found, by analysing all measures in relation to investments, energy production and maintenance costs as decision parameters. Often a more erosion-resistant design, instead of choosing the turbine design with the highest efficiency, will lead to higher revenue. The paper will discuss the influencing parameters on hydro-abrasive erosion and the problems to acquire this information. There are different optimisation possibilities, which will be shown in different case studies. One key aspect to reduce the erosion and prolong the operation time of the components is to coat all relevant parts. But it is very important that this decision is taken early in the design stage, as the design has to be adapted to the requirements of the coating process. The quality of coatings and their impact on the operation will be discussed in detail in the paper as due to the non-availability of standards many questions arise in projects.

  3. Hydro- abrasive jet machining modeling for computer control and optimization

    NASA Astrophysics Data System (ADS)

    Groppetti, R.; Jovane, F.

    1993-06-01

    Use of hydro-abrasive jet machining (HAJM) for machining a wide variety of materials—metals, poly-mers, ceramics, fiber-reinforced composites, metal-matrix composites, and bonded or hybridized mate-rials—primarily for two- and three-dimensional cutting and also for drilling, turning, milling, and deburring, has been reported. However, the potential of this innovative process has not been explored fully. This article discusses process control, integration, and optimization of HAJM to establish a plat-form for the implementation of real-time adaptive control constraint (ACC), adaptive control optimiza-tion (ACO), and CAD/CAM integration. It presents the approach followed and the main results obtained during the development, implementation, automation, and integration of a HAJM cell and its computer-ized controller. After a critical analysis of the process variables and models reported in the literature to identify process variables and to define a process model suitable for HAJM real-time control and optimi-zation, to correlate process variables and parameters with machining results, and to avoid expensive and time-consuming experiments for determination of the optimal machining conditions, a process predic-tion and optimization model was identified and implemented. Then, the configuration of the HAJM cell, architecture, and multiprogramming operation of the controller in terms of monitoring, control, process result prediction, and process condition optimization were analyzed. This prediction and optimization model for selection of optimal machining conditions using multi-objective programming was analyzed. Based on the definition of an economy function and a productivity function, with suitable constraints relevant to required machining quality, required kerfing depth, and available resources, the model was applied to test cases based on experimental results.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  5. The effects of abrasives on electrical submersible pumps

    SciTech Connect

    Wilson, B.L. )

    1990-06-01

    The electrical submersible pump (ESP) is a high-speed rotating device. Its operational life in oil wells can depend on the type and quantities of abrasives present in the produced fluid. This paper reports on a set of experiments performed in a specialized abrasive test loop. In the test, the size and quantity of abrasives were varied along with flow rate through the pump. This paper also examines recent literature on sand production and explores some of the practical problems in sand measurement.

  6. Endoscopic transluminal pancreatic necrosectomy using a self-expanding metal stent and high-flow water-jet system

    PubMed Central

    Hritz, István; Fejes, Roland; Székely, András; Székely, Iván; Horváth, László; Sárkány, Ágnes; Altorjay, Áron; Madácsy, László

    2013-01-01

    Walled-off pancreatic necrosis and a pancreatic abscess are the most severe complications of acute pancreatitis. Surgery in such critically ill patients is often associated with significant morbidity and mortality within the first few weeks after the onset of symptoms. Minimal invasive approaches with high success and low mortality rates are therefore of considerable interest. Endoscopic therapy has the potential to offer safe and effective alternative treatment. We report here on 3 consecutive patients with infected walled-off pancreatic necrosis and 1 patient with a pancreatic abscess who underwent direct endoscopic necrosectomy 19-21 d after the onset of acute pancreatitis. The infected pancreatic necrosis or abscess was punctured transluminally with a cystostome and, after balloon dilatation, a non-covered self-expanding biliary metal stent was placed into the necrotic cavity. Following stent deployment, a nasobiliary pigtail catheter was placed into the cavity to ensure continuous irrigation. After 5-7 d, the metal stent was removed endoscopically and the necrotic cavity was entered with a therapeutic gastroscope. Endoscopic debridement was performed via the simultaneous application of a high-flow water-jet system; using a flush knife, a Dormia basket, and hot biopsy forceps. The transluminal endotherapy was repeated 2-5 times daily during the next 10 d. Supportive care included parenteral antibiotics and jejunal feeding. All patients improved dramatically and with resolution of their septic conditions; 3 patients were completely cured without any further complications or the need for surgery. One patient died from a complication of prolonged ventilation severe bilateral pneumonia, not related to the endoscopic procedure. No procedure related complications were observed. Transluminal endoscopic necrosectomy with temporary application of a self-expanding metal stent and a high-flow water-jet system shows promise for enhancing the potential of this endoscopic

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

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1987-01-01

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

  8. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    NASA Astrophysics Data System (ADS)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  9. Estimating Rock Strength Parameters from Rock Abrasion Tool (RAT) Grinds

    NASA Astrophysics Data System (ADS)

    Thomson, B. J.; Bridges, N. T.; Cohen, J.; Hurowitz, J.; Lennon, A.

    2011-03-01

    We have developed an empirical correlation between rock abrasion tool (RAT) grind energy and compressive strength. This correlation can be used to infer the physical properties of rocks ground by the MER rovers on Mars.

  10. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... excessive restorative materials, such as gold, and to smooth rough surfaces from oral restorations, such...

  11. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... excessive restorative materials, such as gold, and to smooth rough surfaces from oral restorations, such...

  12. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... excessive restorative materials, such as gold, and to smooth rough surfaces from oral restorations, such...

  13. Computed tomography to quantify tooth abrasion

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

    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.

  14. Method of protecting surfaces from abrasion and abrasion resistant articles of manufacture

    DOEpatents

    Hirschfeld, T.B.

    1988-06-09

    Surfaces of fabricated structures are protected from damage by impacting particulates by a coating of hard material formed as a mass of thin flexible filaments having root ends secured to the surface and free portions which can flex and overlap to form a resilient cushioning mat which resembles hair or fur. The filamentary coating covers the underlying surface with hard abrasion resistance material while also being compliant and capable of local accommodation to particle impacts. The coating can also function as thermal and/or acoustical insulation and has a friction reducing effect. 11 figs.

  15. [Dependence of the dentinal abrasion of human teeth on their microhardness].

    PubMed

    Remizov, S M; Pruzhanskiĭ, L Iu

    1989-01-01

    The dentin resistance against abrasion was studied as related to its microhardness. Sections of 15 intact teeth were investigated (central upper incisors). Water suspensions (40% weight-to weight) of dicalcium phosphate (DCP, FRG; and DKF-1 and DKF-2, USSR) were used as abrasives. Dentin microhardness was measured with a PMT-3 device, and abrasion assessed with profilographic technique. Dentin abrasion was related to its microhardness and to the kind of abrasive used. Dentin abrasion increased as its microhardness decreased. DCF showed minimal abrasive effect, DKF-2 had maximal effect with DKF-1 keeping the intermediate position.

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

    SciTech Connect

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

    2012-01-01

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

  17. Acoustic and Doppler radar detection of buried land mines using high-pressure water jets

    NASA Astrophysics Data System (ADS)

    Denier, Robert; Herrick, Thomas J.; Mitchell, O. Robert; Summers, David A.; Saylor, Daniel R.

    1999-08-01

    The goal of the waterjet-based mine location and identification project is to find a way to use waterjets to locate and differentiate buried objects. When a buried object is struck with a high-pressure waterjets, the impact will cause characteristic vibrations in the object depending on the object's shape and composition. These vibrations will be transferred to the ground and then to the water stream that is hitting the object. Some of these vibrations will also be transferred to the air via the narrow channel the waterjet cuts in the ground. Currently the ground vibrations are detected with Doppler radar and video camera sensing, while the air vibrations are detected with a directional microphone. Data is collected via a Labview based data acquisition system. This data is then manipulated in Labview to produce the associated power spectrums. These power spectra are fed through various signal processing and recognition routines to determine the probability of there being an object present under the current test location and what that object is likely to be. Our current test area consists of a large X-Y positioning system placed over approximately a five-foot circular test area. The positioning system moves both the waterjet and the sensor package to the test location specified by the Labview control software. Currently we are able to locate buried land mine models at a distance of approximately three inches with a high degree of accuracy.

  18. Remote laser cutting of CFRP: influence of the edge quality on fatigue strength

    NASA Astrophysics Data System (ADS)

    Stock, Johannes W.; Zaeh, Michael F.; Spaeth, Justinian P.

    2014-02-01

    The additional weight of the batteries in electric cars can be compensated by using carbon fiber reinforced plastics (CFRP) for structural parts of the passenger cell. Various machining processes for CFRP are currently subject to investigations. Milling and abrasive waterjet cutting implicate fiber pull out or delamination and, thus, do not thoroughly meet the requirements for mass production. Despite this, laser beam cutting has a great potential in large scale cutting of CFRP and is a predominant research topic. Remote laser beam cutting especially provides a good cut surface quality. Currently, the correlation between cutting parameters and edge quality is not sufficiently known. In particular, studies on the dynamic strength of remote laser cut parts are missing. Therefore, fatigue testing was performed with specimens cut by laser radiation and the results were compared with others made by milling and abrasive waterjet cutting. With these experiments, a comparable study of the different methods of CFRP cutting was achieved. The influence of both the heat affected zone (HAZ) and of defects like micro-fissures on the fatigue strength were evaluated.

  19. Degradation in the fatigue resistance of dentin by bur and abrasive air-jet preparations.

    PubMed

    Majd, H; Viray, J; Porter, J A; Romberg, E; Arola, D

    2012-09-01

    The objective of this investigation was to distinguish whether the instruments commonly used for cutting dentin cause degradation in strength or fatigue behavior. Beams of coronal dentin were obtained from unrestored 3(rd) molars and subjected to either quasi-static or cyclic flexural loading to failure. The surfaces of selected beams were treated with a conventional straight-sided bur or with an abrasive air jet laden with glass particles. Under monotonic loading, there was no difference in the strength or Weibull parameters obtained for the control or treated beams. However, the fatigue strength of dentin receiving bur and air-jet treatments was significantly lower (p ≤ 0.0001) than that of the control. The bur treatment resulted in the largest overall degree of degradation, with nearly 40% reduction in the endurance limit and even more substantial decrease in the fatigue life. The methods currently used for cavity preparations substantially degrade the durability of dentin.

  20. Overview of a new slicing method: Fixed Abrasive Slicing Technique (FAST)

    NASA Technical Reports Server (NTRS)

    Schmid, F.; Smith, M. B.; Khattak, C. P.

    1982-01-01

    The fixed abrasive slicing technique (FAST) was developed to slice silicon ingots more effectively. It was demonstrated that 25 wafers/cm can be sliced from 10 cm diameter and 19 wafers/cm from 15 cm diameter ingots. This was achieved with a combination of machine development and wire-blade development programs. Correlation was established between cutting effectiveness and high surface speeds. A high speed slicer was designed and fabricated for FAST slicing. Wirepack life of slicing three 10 cm diameter ingots was established. Electroforming techniques were developed to control widths and prolong life of wire-blades. Economic analysis indicates that the projected add-on price of FAST slicing is compatible with the DOE price allocation to meet the 1986 cost goals.

  1. Rotary ultrasonic machining of CFRP: a mechanistic predictive model for cutting force.

    PubMed

    Cong, W L; Pei, Z J; Sun, X; Zhang, C L

    2014-02-01

    Cutting force is one of the most important output variables in rotary ultrasonic machining (RUM) of carbon fiber reinforced plastic (CFRP) composites. Many experimental investigations on cutting force in RUM of CFRP have been reported. However, in the literature, there are no cutting force models for RUM of CFRP. This paper develops a mechanistic predictive model for cutting force in RUM of CFRP. The material removal mechanism of CFRP in RUM has been analyzed first. The model is based on the assumption that brittle fracture is the dominant mode of material removal. CFRP micromechanical analysis has been conducted to represent CFRP as an equivalent homogeneous material to obtain the mechanical properties of CFRP from its components. Based on this model, relationships between input variables (including ultrasonic vibration amplitude, tool rotation speed, feedrate, abrasive size, and abrasive concentration) and cutting force can be predicted. The relationships between input variables and important intermediate variables (indentation depth, effective contact time, and maximum impact force of single abrasive grain) have been investigated to explain predicted trends of cutting force. Experiments are conducted to verify the model, and experimental results agree well with predicted trends from this model.

  2. The effect of daily fluoride mouth rinsing on enamel erosive/abrasive wear in situ.

    PubMed

    Stenhagen, K R; Hove, L H; Holme, B; Tveit, A B

    2013-01-01

    It is not known whether application of fluoride agents on enamel results in lasting resistance to erosive/abrasive wear. We investigated if one daily mouth rinse with sodium fluoride (NaF), stannous fluoride (SnF(2)) or titanium tetrafluoride (TiF(4)) solutions protected enamel against erosive/abrasive wear in situ (a paired, randomised and blind study). Sixteen molars were cut into 4 specimens, each with one amalgam filling (measurement reference surface). Two teeth (2 × 4 specimens) were mounted bilaterally (buccal aspects) on acrylic mandibular appliances and worn for 9 days by 8 volunteers. Every morning, the specimens were brushed manually with water (30 s) extra-orally. Then fluoride solutions (0.4% SnF(2) pH 2.5; 0.15% TiF(4) pH 2.1; 0.2% NaF pH 6.5, all 0.05 M F) were applied (2 min). Three of the specimens from each tooth got different treatment, and the fourth served as control. At midday, the specimens were etched for 2 min in 300 ml fresh 0.01 M hydrochloric acid and rinsed in tap water. This etch procedure was repeated in the afternoon. Topographic measurements were performed by a white-light interferometer. Mean surface loss (±SD) for 16 teeth after 9 days was: SnF(2) 1.8 ± 1.9 µm, TiF(4) 3.1 ± 4.8 µm, NaF 26.3 ± 4.7 µm, control 32.3 ± 4.4 µm. Daily rinse with SnF(2), TiF(4) and NaF resulted in 94, 90 and 18% reduction in enamel erosive/abrasive wear, respectively, compared with control (p < 0.05). The superior protective effect of daily rinse with either stannous or titanium tetrafluoride solutions on erosive/abrasive enamel wear is promising.

  3. Abrasion resistant silicon nitride based articles

    SciTech Connect

    Sarin, V.K.; Buijan, S.T.; Penty, R.A.

    1984-02-28

    A composite article and cutting tool are prepared by densification to form a body consisting essentially of particles of hard refractory material uniformly distributed in a matrix consisting essentially of a first phase and a second phase, said first phase consisting essentially of crystalline silicon nitride and said second phase being an intergranular refractory phase comprising silicon nitride and a suitable densification aid selected from the group consisting of yttrium oxide, zirconium oxide, hafnium oxide and the lanthanade rare earth oxides and mixture thereof.

  4. Degradation of nontoxic fouling-release coatings as a result of abrasion and long-term exposure

    SciTech Connect

    Meyer, A.E.; Baier, R.E.; Forsberg, R.L.

    1995-06-01

    Previous work by this research group demonstrates that methylsilicone-based coatings having critical surface tensions between 20 and 25 mN/m allow easy mechanical detachment of zebra mussel infestations and other fouling for at least 2 years. Continuing evaluations of the coated test panels and trash racks at test sites in western New York confirm and extend the 2-year findings. Coatings which, in addition, contain elutable oils display an apparent further resistance to initial colonization by zebra mussels, but this early benefit does not carry over to the brush-removal forces required for cleaning of the once-fouled coating. Several of the elastomeric methylsilicone coatings are prone to cutting and abrasion damage, limiting their suitability for heavy-duty use and/or situations requiring periodic cleaning. Since standard tests for abrasion and wear developed for paints are not applicable to elastomeric coatings, our laboratory is using a brush abrasion test to evaluate fouling-release coatings for an increasing series of wet brushing cycles.

  5. Abrasive tip treatment for use on compressor blades

    NASA Technical Reports Server (NTRS)

    Pedersen, H. C.

    1984-01-01

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

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

    NASA Technical Reports Server (NTRS)

    2006-01-01

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

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

  7. Reuse of waste cutting sand at Lawrence Livermore National Laboratory

    SciTech Connect

    Mathews, S., LLNL

    1998-02-25

    Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchases by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in ac concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved.

  8. Abrasion of Candidate Spacesuit Fabrics by Simulated Lunar Dust

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  9. Abrasive wear and surface roughness of contemporary dental composite resin.

    PubMed

    Han, Jian-min; Zhang, Hongyu; Choe, Hyo-Sun; Lin, Hong; Zheng, Gang; Hong, Guang

    2014-01-01

    The purpose of this study was to evaluate the abrasive wear and surface roughness of 20 currently available commercial dental composite resins, including nanofilled, supra-nanofilled, nanohybrid and microhybrid composite resins. The volume loss, maximum vertical loss, surface roughness (R(a)) and surface morphology [Scanning electron microscopy (SEM)] were determined after wear. The inorganic filler content was determined by thermogravimetric analysis. The result showed that the volume loss and vertical loss varied among the materials. The coefficients of determination (R(2)) of wear volume loss and filler content (wt%) was 0.283. SEM micrographs revealed nanofilled composites displayed a relatively uniform wear surfaces with nanoclusters protrusion, while the performance of nanohybrid composites varied. The abrasive wear resistance of contemporary dental composite resins is material-dependent and cannot be deduced from its category, filler loading and composite matrix; The abrasive wear resistance of some flowable composites is comparable to the universal/posterior composite resins.

  10. Prepolishing on a CNC platform with bound abrasive contour tools

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

    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 3-5μm 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.

  11. Theoretical Analysis and Experimental Study on the Coating Removal from Passenger-Vehicle Plastics for Recycling by Using Water Jet Technology

    NASA Astrophysics Data System (ADS)

    Zhang, Hongshen; Chen, Ming

    2015-11-01

    The recovery and utilization of automotive plastics are a global concern because of the increasing number of end-of-life vehicles. In-depth studies on technologies for the removal of coatings from automotive plastics can contribute to the high value-added levels of the recycling and utilization of automotive plastic. The liquid waste generated by removing chemical paint by using traditional methods is difficult to handle and readily produces secondary pollution. Therefore, new, clean, and highly efficient techniques of paint removal must be developed. In this article, a method of coating removal from passenger-vehicle plastics was generated based on high-pressure water jet technology to facilitate the recycling of these plastics. The established technology was theoretically analyzed, numerically simulated, and experimentally studied. The high-pressure water jet equipment for the removal of automotive-plastic coatings was constructed through research and testing, and the detailed experiments on coating removal rate were performed by using this equipment. The results showed that high-pressure water jet technology can effectively remove coatings on the surfaces of passenger-vehicle plastics. The research also revealed that the coating removal rate increased as jet pressure ( P) increased and then decreased when jet moving speed ( Vn) increased. The rate decreased as the distance from nozzle to work piece ( S nw ) and the nozzle angle ( Φ) increased. The mathematical model for the rate of removal of coatings from bumper surfaces by water jet was derived based on the experiment data and can effectively predict coating removal rate under different operating conditions.

  12. Precision laser cutting

    SciTech Connect

    Kautz, D.D.; Anglin, C.D.; Ramos, T.J.

    1990-01-19

    Many materials that are otherwise difficult to fabricate can be cut precisely with lasers. This presentation discusses the advantages and limitations of laser cutting for refractory metals, ceramics, and composites. Cutting in these materials was performed with a 400-W, pulsed Nd:YAG laser. Important cutting parameters such as beam power, pulse waveforms, cutting gases, travel speed, and laser coupling are outlined. The effects of process parameters on cut quality are evaluated. Three variables are used to determine the cut quality: kerf width, slag adherence, and metallurgical characteristics of recast layers and heat-affected zones around the cuts. Results indicate that ductile materials with good coupling characteristics (such as stainless steel alloys and tantalum) cut well. Materials lacking one or both of these properties (such as tungsten and ceramics) are difficult to cut without proper part design, stress relief, or coupling aids. 3 refs., 2 figs., 1 tab.

  13. Friability and crushing strength of micrometer-size diamond abrasives used in microgrinding of optical glass

    NASA Astrophysics Data System (ADS)

    Zhou, Yiyang; Takahashi, Toshio; Quesnel, David J.; Funkenbusch, Paul D.

    1996-04-01

    In abrasive grinding, the properties of the abrasives and their response to impact loading play a significant role in determining the results achievable. For micrometer-size diamond abrasives used for bound-abrasive microgrinding of optical glass, friability testing is used to estimate the related particle properties. Friability and crushing strength of diamond abrasives are estimated based on the data from comminution of sample powders on a commercial SPEX mixer/mill. Different diamond abrasives as well as a CBN abrasive are tested. Evolution of powder size and size distribution with comminution time is characterized with a HORIBA laser scattering analyzer. Correlation is established for the impact stress and the probability of fracture during comminution. This study demonstrates how to combine the ease of data acquisition found in a conventional friability test with the capability of predicting specific mechanical properties normally found only by crushing individual abrasive particles.

  14. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain...

  15. 9 CFR 311.14 - Abrasions, bruises, abscesses, pus, etc.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Abrasions, bruises, abscesses, pus, etc. 311.14 Section 311.14 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... excised, leaving only sound, normal tissue, which may be passed for human food. Any organ or other part...

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

    PubMed Central

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

    2009-01-01

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

  17. Development of a thermal reclamation system for spent blasting abrasive

    SciTech Connect

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

    1991-01-01

    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.

  18. 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...

  19. Cutting state identification

    SciTech Connect

    Berger, B.S.; Minis, I.; Rokni, M.

    1997-12-31

    Cutting states associated with the orthogonal cutting of stiff cylinders are identified through an analysis of the singular values of a Toeplitz matrix of third order cumulants of acceleration measurements. The ratio of the two pairs of largest singular values is shown to differentiate between light cutting, medium cutting, pre-chatter and chatter states. Sequences of cutting experiments were performed in which either depth of cut or turning frequency was varied. Two sequences of experiments with variable turning frequency and five with variable depth of cut, 42 cutting experiments in all, provided a database for the calculation of third order cumulants. Ratios of singular values of cumulant matrices find application in the analysis of control of orthogonal cutting.

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

    SciTech Connect

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

    2010-08-19

    Current specifications require AWJ-cut aluminum parts for fatigue critical aerospace structures to go through subsequent processing due to concerns of degradation in fatigue performance. The requirement of secondary process for AWJ-machined parts greatly negates the cost effectiveness of waterjet technology. Some cost savings are envisioned if it can be shown that AWJ net cut parts have comparable durability properties as those conventionally machined. To revisit and upgrade the specifications for AWJ machining of aircraft aluminum, “Dog-bone” specimens, with and without secondary processes, were prepared for independent fatigue tests at Boeing and Pacific Northwest National Laboratory (PNNL). Test results show that the fatigue life is proportional to quality levels of machined edges or inversely proportional to the surface roughness Ra . Even at highest quality level, the average fatigue life of AWJ-machined parts is about 30% shorter than those of conventionally machined counterparts. Between two secondary processes, dry-grit blasting with aluminum oxide abrasives until the striation is removed visually yields excellent result. It actually prolongs the fatigue life of parts at least three times higher than that achievable with conventional machining. Dry-grit blasting is relatively simple and inexpensive to administrate and, equally important, alleviates the concerns of garnet embedment.

  1. Brushing abrasion of luting cements under neutral and acidic conditions.

    PubMed

    Buchalla, W; Attin, T; Hellwig, E

    2000-01-01

    Four resin based materials (Compolute Aplicap, ESPE; Variolink Ultra, Vivadent; C&B Metabond, Parkell and Panavia 21, Kuraray), two carboxylate cements (Poly-F Plus, Dentsply DeTrey and Durelon Maxicap, ESPE), two glass-ionomer cements (Fuji I, GC and Ketac-Cem Aplicap, ESPE), one resin-modified glass ionomer cement (Vitremer, 3M) one polyacid-modified resin composite (Dyract Cem, Dentsply DeTrey) and one zinc phosphate cement (Harvard, Richter & Hoffmann) were investigated according to their brushing resistance after storage in neutral and acidic buffer solutions. For this purpose 24 cylindrical acrylic molds were each filled with the materials. After hardening, the samples were stored for seven days in 100% relative humidity and at 37 degrees C. Subsequently, they were ground flat and polished. Then each specimen was covered with an adhesive tape leaving a 4 mm wide window on the cement surface. Twelve samples of each material were stored for 24 hours in a buffer solution with a pH of 6.8. The remaining 12 samples were placed in a buffer with a pH of 3.0. All specimens were then subjected to a three media brushing abrasion (2,000 strokes) in an automatic brushing machine. Storage and brushing were performed three times. After 6,000 brushing strokes per specimen, the tape was removed. Brushing abrasion was measured with a computerized laser profilometer and statistically analyzed with ANOVA and Tukey's Standardized Range Test (p < or = 0.05). The highest brushing abrasion was found for the two carboxylate cements. The lowest brushing abrasion was found for one resin based material, Compolute Aplicap. With the exception of three resin-based materials, a lower pH led to a higher brushing abrasion.

  2. Dash line glass- and sapphire-cutting with high power USP laser

    NASA Astrophysics Data System (ADS)

    Mishchik, Konstantin; Chassagne, Bruno; Javaux-Léger, Clémentine; Hönninger, Clemens; Mottay, Eric; Kling, Rainer; Lopez, John

    2016-03-01

    Glass cutting is a subject of high interest for flat panel display and consumer electronics industries. Among laser-based, water jet-based and diamond tool-based existing solutions, ultra-short pulses (USP) appear as a promising technology since this laser technology has the unique capacity to produce highly localized bulk modification owing to non-linear absorption. The cutting using USP lasers could be performed either by full ablation which is slow and generates a lot of dust, by controlled fracture propagation which is slow as well and may lead to path deviation, by stealth dicing which produces rough sidewalls, or by self-breaking induced by in-volume laser irradiation. The laser treatment is often continuous which is not necessary to perform glass cutting and may lead to over-exposure. In this paper we report on single pass glass and sapphire cutting using an USP laser (20W @200kHz or 8W@2MHz) using dash line laser treatment along the cutting trajectory. In-volume energy deposition was done along the glass thickness owing to a Bessel beam. The results will be discussed in terms of sidewall profile and roughness, path deviation, rim sharpness, energy dose and feed rate. Dash line treatment enables to tune the energy deposition and to produce the cutting effect but with a narrower heat affected zone, a better sidewall quality and a more accurate trajectory control of the cutting path.

  3. Numerical modelling of tool wear in turning with cemented carbide cutting tools

    SciTech Connect

    Franco, P.; Estrems, M.; Faura, F.

    2007-04-07

    A numerical model is proposed for analysing the flank and crater wear resulting from the loss of material on cutting tool surface in turning processes due to wear mechanisms of adhesion, abrasion and fracture. By means of this model, the material loss along cutting tool surface can be analysed, and the worn surface shape during the workpiece machining can be determined. The proposed model analyses the gradual degradation of cutting tool during turning operation, and tool wear can be estimated as a function of cutting time. Wear-land width (VB) and crater depth (KT) can be obtained for description of material loss on cutting tool surface, and the effects of the distinct wear mechanisms on surface shape can be studied. The parameters required for the tool wear model are obtained from bibliography and experimental observation for AISI 4340 steel turning with WC-Co cutting tools.

  4. Cuts and puncture wounds

    MedlinePlus

    ... MINOR CUTS Wash your hands with soap or antibacterial cleanser to prevent infection. Then, wash the cut ... Use direct pressure to stop the bleeding. Apply antibacterial ointment and a clean bandage that will not ...

  5. 76 FR 12702 - Certain Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia, Italy, and the Republic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ...) abrasion-resistant steels (i.e., USS AR 400, USS AR 500); (5) products made to ASTM A202, A225, A514 grade S, A517 grade S, or their proprietary equivalents; (6) ball bearing steels; (7) tool steels; and (8... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia,...

  6. 76 FR 12322 - Certain Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia, Italy, Japan, and the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... ASTM A710 and A736 or their proprietary equivalents; (4) abrasion-resistant steels (i.e., USS AR 400... equivalents; (6) ball bearing steels; (7) tool steels; and (8) silicon manganese steel or silicon electric... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia,...

  7. 77 FR 21527 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... proprietary equivalents; (4) abrasion-resistant steels (i.e., USS AR 400, USS AR 500); (5) products made to ASTM A202, A225, A514 grade S, A517 grade S, or their proprietary equivalents; (6) ball bearing steels... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From the...

  8. Device for cutting protrusions

    DOEpatents

    Bzorgi, Fariborz M.

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  9. Nanometric Finishing on Biomedical Implants by Abrasive Flow Finishing

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  10. Erosion, cavitation, and abrasion resistance of choke trim materials

    SciTech Connect

    Seger, F.O.; Maroofian, I.

    1984-05-01

    An experimental investigation was performed to determine the relative erosion, abrasion and cavitation resistance characteristics of selected materials. Testing was conducted under controlled laboratory conditions to simulate service conditions encountered in production and injection chokes. The testing effort is ongoing. The data accumulated allow informed material selection of conventional and novel trim for all chokes, valves, flow metering orifices, fixed beans and other devices used during drilling, completion and production of offshore and onshore oil and gas wells. Sintered silicon carbide, and tungsten carbide with minimum binder content were the most erosion and abrasion resistant of the materials tested. Cobalt base alloys bar and nickelchrome alloy 625 bar proved to be most cavitation resistant.

  11. Self inflicted corneal abrasions due to delusional parasitosis

    PubMed Central

    Meraj, Adeel; Din, Amad U; Larsen, Lynn; Liskow, Barry I

    2011-01-01

    The authors report a case of self inflicted bilateral corneal abrasions and skin damage due to ophthalmic and cutaneous delusional parasitosis. A male in his 50s presented with a 10 year history of believing that parasites were colonizing his skin and biting into his skin and eyes. The patient had received extensive medical evaluations that found no evidence that symptoms were due to a medical cause. He was persistent in his belief and had induced bilateral corneal abrasions and skin damage by using heat lamps and hair dryers in an attempt to disinfect his body. The patient was treated with olanzapine along with treatment for his skin and eyes. His delusional belief system persisted but no further damage to his eyes and skin was noted on initial follow-up. PMID:22689836

  12. Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

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

    SciTech Connect

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

    2001-05-01

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

  14. Abrasive-waterjet machining of ceramic-coated materials

    NASA Astrophysics Data System (ADS)

    Hashish, M.; Whalen, J.

    1991-09-01

    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.

  15. Abrasion Testing of Critical Components of Hydrokinetic Devices

    SciTech Connect

    Worthington, Monty; Ali, Muhammad; Ravens, Tom

    2013-12-06

    The objective of the Abrasion Testing of Critical Components of Hydrokinetic Devices (Project) was to test critical components of hydrokinetic devices in waters with high levels of suspended sediment – information that is widely applicable to the hydrokinetic industry. Tidal and river sites in Alaska typically have high suspended sediment concentrations. High suspended sediment also occurs in major rivers and estuaries throughout the world and throughout high latitude locations where glacial inputs introduce silt into water bodies. In assessing the vulnerability of technology components to sediment induced abrasion, one of the greatest concerns is the impact that the sediment may have on device components such as bearings and seals, failures of which could lead to both efficiency loss and catastrophic system failures.

  16. Occlusive Dressings and the Healing of Standardized Abrasions

    PubMed Central

    Beam, Joel W

    2008-01-01

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

  17. Abrasion of eroded root dentine brushed with different toothpastes.

    PubMed

    De Menezes, Márcio; Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Messias, Danielle Cristine Furtado; Serra, Mônica Campos

    2004-09-01

    This study evaluated the surface roughness change and wear provided by different dentifrices on root dentine previously exposed to erosive challenges. According to a randomized complete block design, 150 slabs of bovine root dentine (6 x 3 x 2 mm) were ground flat and polished. In an area of 4 x 3 mm on the dentine surface, specimens were submitted to five erosive/abrasive events, each one composed by: exposure to Sprite Diet or distilled water for 5 min, then to a remineralizing solution for 1 min, and simulation of 5,000 brushing strokes. Four dentifrices--regular (RE), baking soda (BS), whitening (WT) and tartar control (TC)--and distilled water (CO), used as control, were compared. Final texture and the wear depth were evaluated using a profilometer. ANOVA did not show significant interaction, indicating that the effect of dentifrices on both surface roughness change and wear did not depend on whether or not the dentine was eroded ( p>0.05). There was no difference between abrasion of eroded and sound dentine. The Tukey's test revealed that WT, BS and TC provided the highest increase in surface roughness differing from RE and CO. TC yielded the deepest wear of root dentine, whereas RE and CO, the shallowest. No significant difference in wear among BS, TC and WT were observed. Within the limitations of this study, the data showed that abrasion of both eroded and sound root dentine was dependent on the dentifrice used. PMID:15146320

  18. Shotcup petal abrasions in close range .410-caliber shotgun injuries.

    PubMed

    Dowling, G P; Dickinson, J A; Cooke, C T

    1988-01-01

    Shotcup petal abrasions centered around a shotgun wound of entrance are generally thought to occur at a range of 30 to 90 cm. A suicidal .410-caliber shotgun injury of the right eye is described in which typical petal abrasions were noted around the entrance wound. However, significant soot deposition around the wound suggested that the range of fire was less than 30 cm and perhaps closer to 15 cm. Test-firing of the weapon and ammunition used by the decedent showed some spread of the shotcup petals at a range of 7.5 cm, progressing to maximum spread at 30 to 52.5 cm. Further testing with other .410 ammunition, containing shotcups, confirmed the spread of shotcup petals at ranges less than 30 cm, irrespective of manufacturer, shotshell length, and birdshot size. When a variety of shotguns were tested, it was found that one weapon with a very short barrel and cylinder bore did not exhibit petal spread until a range of 30 cm was reached. The remaining shotguns, with longer barrels and full choke, all demonstrated definite petal spread at a range of 12.5 cm. The long, narrow configuration of .410 shotcup petals may explain their early spread and the production of petal abrasions at ranges of less than 30 cm.

  19. Dressing methods for grinding wheels made of superhard abrasive materials

    NASA Astrophysics Data System (ADS)

    Spur, G.

    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.

  20. Abrasion of Candidate Spacesuit Fabrics by Simulated Lunar Dust

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  1. Proportion of soft tissue in selected bone cuts fed primarily as enrichments to large carnivores.

    PubMed

    Felicetti, Laura; Kearney, Celeste C; Woodward, Lloyd; Dierenfeld, Ellen S

    2008-03-01

    Zoos often offer large bones or cuts of meat containing bone (bone cuts) to carnivores to provide oral stimulation and behavioral enrichment. Because of its abrasive action, the act of chewing on a bone can increase the oral health of large felids as well as provide an enriching activity. Unfortunately, because the quantity of edible tissue on the bones is usually unknown, when feeding these cuts one can easily miscalculate an animal's caloric and nutrient intake. To fully comprehend the contribution of bones as a dietary item as opposed to an enrichment item, we removed the soft tissue from a total of 70 samples, representing 14 types of bone cuts commonly used in managed carnivore feeding programs. Across types of cuts, soft tissue averaged 50% of wet weight, with pork knuckles averaging the lowest (23%) and horse shanks the greatest (74%) percent soft tissue. Zoo Biol 27:154-158, 2008. (c) 2008 Wiley-Liss, Inc.

  2. Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

    NASA Astrophysics Data System (ADS)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.

    2011-01-01

    The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN-Al2O3-TiCN-TiN. The insert performance was evaluated based on the insert's edge resistant towards the machining parameters used at high cutting speed range of machining Ti-6Al-4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev and depth of cut of 0.10-0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium alloy onto the flank and rake faces demonstrates a strong bond at the workpiece-tool interface.

  3. Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

    SciTech Connect

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.

    2011-01-17

    The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN-Al2O3-TiCN-TiN. The insert performance was evaluated based on the insert's edge resistant towards the machining parameters used at high cutting speed range of machining Ti-6Al-4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev and depth of cut of 0.10-0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium alloy onto the flank and rake faces demonstrates a strong bond at the workpiece-tool interface.

  4. Laser cutting plastic materials

    SciTech Connect

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  5. Ultrasonic Cutting of Foods

    NASA Astrophysics Data System (ADS)

    Schneider, Yvonne; Zahn, Susann; Rohm, Harald

    In the field of food engineering, cutting is usually classified as a mechanical unit operation dealing with size reduction by applying external forces on a bulk product. Ultrasonic cutting is realized by superpositioning the macroscopic feed motion of the cutting device or of the product with a microscopic vibration of the cutting tool. The excited tool interacts with the product and generates a number of effects. Primary energy concentration in the separation zone and the modification of contact friction along the tool flanks arise from the cyclic loading and are responsible for benefits such as reduced cutting force, smooth cut surface, and reduced product deformation. Secondary effects such as absorption and cavitation originate from the propagation of the sound field in the product and are closely related to chemical and physical properties of the material to be cut. This chapter analyzes interactions between food products and ultrasonic cutting tools and relates these interactions with physical and chemical product properties as well as with processing parameters like cutting velocity, ultrasonic amplitude and frequency, and tool design.

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

    NASA Astrophysics Data System (ADS)

    Manivannan, R.; Ramanathan, S.

    2009-01-01

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

  7. Development of a fixed abrasive slicing technique (FAST) for reducing the cost of photovoltaic wafers. Final subcontract report, 9 January 1991--14 April 1991

    SciTech Connect

    Schmid, F.

    1991-12-01

    This report examines a wafer slicing technique developed by Crystal Systems, Inc. that reduces the cost of photovoltaic wafers. This fixed, abrasive slicing technique (FAST) uses a multiwire bladepack and a diamond-plated wirepack; water is the coolant. FAST is in the prototype production stage and reduces expendable material costs while retaining the advantages of a multiwire slurry technique. The cost analysis revealed that costs can be decreased by making more cuts per bladepack and slicing more wafers per linear inch. Researchers studied the degradation of bladepacks and increased wirepack life. 21 refs.

  8. Rotating bits including a plurality of types of preferential cutting elements

    SciTech Connect

    Bidegaray, D. A.

    1985-04-23

    A rotating bit, particularly a rotary bit, is provided with a plurality of teeth incorporating diamond cutting elements of a first and second type. Each type of tooth is particularly adapted to cut a particular type of rock formation. For example, the plurality of the first type of teeth are particularly designed to cut soft to medium-hard rock formations, and the plurality of the second type of teeth are particularly adapted to cut hard or abrasive rock formations. In one embodiment, the first type of teeth are set on the bit face to have a greater exposure from the bit face than the second type of teeth. In that case, the first type of teeth will engage the rock formation first. A second embodiment has the relative disposition of the first and second types of teeth as measured by their disposition from the axis of rotation on the bit reversed. In the case where the teeth, which are adapted for hard rock cutting, extend furthermost from the bit, the rock formation first comes into contact with these teeth and if it should be a hard rock formation, primary cutting action will be accomplished with the hard rock cutting teeth, while the soft rock cutting teeth are held out of contact from the formation to minimize wear of these softer rock cutting teeth. However, when a soft rock formation is encountered, the hard rock teeth will fully embed into the softer rock formation, thereby allowing full engagement of the softer rock formation cutting teeth.

  9. Characterization of nanoparticles from abrasive waterjet machining and electrical discharge machining processes.

    PubMed

    Ling, Tsz Yan; Pui, David Y H

    2013-11-19

    Abrasive Waterjet Machining (AWM) and Electrical Discharge Machining (EDM) processes are found to produce nanoparticles during operation. Impacts of engineered nanoparticles released to the environment and biological system have caused much concern. Similarly, the nanoparticles unintentionally produced by the AWM and EDM can lead to comparable effects. By application of the Nanoparticle Tracking Analysis (NTA) technique, the size distribution and concentration of nanoparticles in the water used in AWM and EDM were measured. The particles generally have a peak size of 100-200 nm. The filtration systems of the AWM and EDM processes were found to remove 70% and 90% the nanoparticles present, respectively. However, the particle concentration of the filtered water from the AWM was still four times higher than that found in regular tap water. These nanoparticles are mostly agglomerated, according to the microscopy analysis. Using the electron dispersive spectroscopy (EDS) technique, the particles are confirmed to come from the debris of the materials cut with the equipment. Since AWM and EDM are widely used, the handling and disposal of used filters collected with nanoparticles, release of nanoparticles to the sewer, and potential use of higher performance filters for these processes will deserve further consideration.

  10. Characterization of nanoparticles from abrasive waterjet machining and electrical discharge machining processes.

    PubMed

    Ling, Tsz Yan; Pui, David Y H

    2013-11-19

    Abrasive Waterjet Machining (AWM) and Electrical Discharge Machining (EDM) processes are found to produce nanoparticles during operation. Impacts of engineered nanoparticles released to the environment and biological system have caused much concern. Similarly, the nanoparticles unintentionally produced by the AWM and EDM can lead to comparable effects. By application of the Nanoparticle Tracking Analysis (NTA) technique, the size distribution and concentration of nanoparticles in the water used in AWM and EDM were measured. The particles generally have a peak size of 100-200 nm. The filtration systems of the AWM and EDM processes were found to remove 70% and 90% the nanoparticles present, respectively. However, the particle concentration of the filtered water from the AWM was still four times higher than that found in regular tap water. These nanoparticles are mostly agglomerated, according to the microscopy analysis. Using the electron dispersive spectroscopy (EDS) technique, the particles are confirmed to come from the debris of the materials cut with the equipment. Since AWM and EDM are widely used, the handling and disposal of used filters collected with nanoparticles, release of nanoparticles to the sewer, and potential use of higher performance filters for these processes will deserve further consideration. PMID:24144041

  11. When Students Cut Themselves

    ERIC Educational Resources Information Center

    Malikow, Max

    2006-01-01

    Masochism, the irrational self-infliction of pain, is more easily defined than understood. Once, a teacher used the word "cutting" only reference to a student skipping class. But, in recent years, it has taken on additional meaning. Cutting, or self-injury, is a deliberate self-harming behavior but without conscious suicidal ideation. To define…

  12. Surface roughness and wear of resin cements after toothbrush abrasion.

    PubMed

    Ishikiriama, Sérgio Kiyoshi; Ordoñéz-Aguilera, Juan Fernando; Maenosono, Rafael Massunari; Volú, Fernanda Lessa Amaral; Mondelli, Rafael Francisco Lia

    2015-01-01

    Increased surface roughness and wear of resin cements may cause failure of indirect restorations. The aim of this study was to evaluate quantitatively the surface roughness change and the vertical wear of four resin cements subjected to mechanical toothbrushing abrasion. Ten rectangular specimens (15 × 5 × 4 mm) were fabricated according to manufacturer instructions for each group (n = 10): Nexus 3, Kerr (NX3); RelyX ARC, 3M ESPE (ARC); RelyX U100, 3M ESPE (U100); and Variolink II, Ivoclar/Vivadent (VL2). Initial roughness (Ra, µm) was obtained through 5 readings with a roughness meter. Specimens were then subjected to toothbrushing abrasion (100,000 cycles), and further evaluation was conducted for final roughness. Vertical wear (µm) was quantified by 3 readings of the real profile between control and brushed surfaces. Data were subjected to analysis of variance, followed by Tukey's test (p < 0.05). The Pearson correlation test was performed between the surface roughness change and wear (p < 0.05). The mean values of initial/final roughness (Ra, µm)/wear (µm) were as follows: NX3 (0.078/0.127/23.175); ARC (0.086/0.246/20.263); U100 (0.296/0.589/16.952); and VL2 (0.313/0.512/22.876). Toothbrushing abrasion increased surface roughness and wear of all resin cements tested, although no correlation was found between those variables. Vertical wear was similar among groups; however, it was considered high and may lead to gap formation in indirect restorations.

  13. Surface roughness and wear of resin cements after toothbrush abrasion.

    PubMed

    Ishikiriama, Sérgio Kiyoshi; Ordoñéz-Aguilera, Juan Fernando; Maenosono, Rafael Massunari; Volú, Fernanda Lessa Amaral; Mondelli, Rafael Francisco Lia

    2015-01-01

    Increased surface roughness and wear of resin cements may cause failure of indirect restorations. The aim of this study was to evaluate quantitatively the surface roughness change and the vertical wear of four resin cements subjected to mechanical toothbrushing abrasion. Ten rectangular specimens (15 × 5 × 4 mm) were fabricated according to manufacturer instructions for each group (n = 10): Nexus 3, Kerr (NX3); RelyX ARC, 3M ESPE (ARC); RelyX U100, 3M ESPE (U100); and Variolink II, Ivoclar/Vivadent (VL2). Initial roughness (Ra, µm) was obtained through 5 readings with a roughness meter. Specimens were then subjected to toothbrushing abrasion (100,000 cycles), and further evaluation was conducted for final roughness. Vertical wear (µm) was quantified by 3 readings of the real profile between control and brushed surfaces. Data were subjected to analysis of variance, followed by Tukey's test (p < 0.05). The Pearson correlation test was performed between the surface roughness change and wear (p < 0.05). The mean values of initial/final roughness (Ra, µm)/wear (µm) were as follows: NX3 (0.078/0.127/23.175); ARC (0.086/0.246/20.263); U100 (0.296/0.589/16.952); and VL2 (0.313/0.512/22.876). Toothbrushing abrasion increased surface roughness and wear of all resin cements tested, although no correlation was found between those variables. Vertical wear was similar among groups; however, it was considered high and may lead to gap formation in indirect restorations. PMID:25466330

  14. The effect of abrasion on corrosion of dental Co-Cr alloys. An in vitro study.

    PubMed

    de Melo, J F; Gjerdet, N R; Erichsen, E S

    1985-05-01

    The effect of abrasion on corrosion of two dental Co-Cr alloys was investigated in vitro. The metals were abraded with a toothbrush and with a piece of tooth enamel. Changes in corrosion potentials and metal release due to the abrasion were measured. Abrasion by tooth enamel caused a persistent drop in corrosion potentials. The release of both chromium and, in particular, cobalt was higher than during brushing. The two alloys tested did not significantly differ with regard to mode and rate of corrosion. It was demonstrated that the corrosion behavior of electrochemically passive dental alloys was affected by abrasion of a magnitude normally encountered during clinical service. PMID:3863447

  15. Laser Prepared Cutting Tools

    NASA Astrophysics Data System (ADS)

    Konrad, Wegener; Claus, Dold; Marcel, Henerichs; Christian, Walter

    Laser pulses with a pulsewidth of a few picoseconds have recently received a lot of attention, solving the problem of manufacturing tools for new materials of superior mechanical properties. Processing thermally sensitive material, such as diamond and CBN structures, can be done without major material deterioration effects. The breakthrough of this new technology becomes possible, if the accuracy and life time requirements of those tools are met. The paper shows in three applications the potential of laser manufacturing of cutting tools. Manufacturing of cutting edges for CFRP cutting needs sharp and stable cutting edges, which are prepared in PCD tools by laser sources in the picosecond pulsewidth regime. Profiling of hybrid bond grinding wheels yields geometric flexibility, which is impossible by mechanical treatment so far. Touch dressing of grinding wheels substantially reduces cutting forces.

  16. Heat sealable, flame and abrasion resistant coated fabric

    NASA Technical Reports Server (NTRS)

    Tschirch, R. P.; Sidman, K. R. (Inventor)

    1983-01-01

    Flame retardant, abrasion resistant elastomeric compositions are disclosed which are comprised of thermoplastic polyurethane polymer and flame retarding amounts of a filler selected from decabromodiphenyloxide and antimony oxide in a 3:1 weight ratio, and decabromodiphenyloxide, antimony oxide, and ammonium polyphosphate in a 3:1:3 weight ratio respectively. Heat sealable coated fabrics employing such elastomeric compositions as coating film are produced by dissolving the elastomeric composition to form a solution, casting the solution onto a release paper and drying it to form an elastomeric film. The film is then bonded to a woven, knitted, or felted fabric.

  17. Diffuse corneal abrasion after ocular exposure to laundry detergent pod.

    PubMed

    Whitney, Rachel E; Baum, Carl R; Aronson, Paul L

    2015-02-01

    Although ocular injury from alkaline household cleaning products is well described, there is less known about the significance and extent of injury with ocular exposure to detergent pods. We report a 12-month-old with diffuse corneal abrasion caused by ocular contact with a laundry detergent pod. In addition to the known risks with aspiration with detergent pods, the potential for severe ocular injury is important for parents and clinicians to recognize. Children with ocular exposure to detergent pods should seek immediate medical care.

  18. Solution of the Roth-Marques-Durian rotational abrasion model

    NASA Astrophysics Data System (ADS)

    Chen, Bryan Gin-Ge

    2011-03-01

    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.

  19. Water Fountains in the Sky: Streaming Water Jets from Aging Star Provide Clues to Planetary-Nebula Formation

    NASA Astrophysics Data System (ADS)

    2002-06-01

    said. "Traditional wisdom says that it takes a disk of material closely orbiting the star to produce jets, but we don't yet know how such a disk could be produced around such an old star," he added. The astronomers are probably very lucky to have caught W43A in what they believe is a brief transitional stage of its life. "Our analysis of the water jets indicates that they are only a few decades old," Imai said. "Once the star collapses of its own gravity into a dense white dwarf, its intense ultraviolet radiation will rip apart the water molecules, making observations such as ours impossible," he added. Planetary nebulae may be the worst-named class of objects in astronomy, because, despite the name, they have nothing to do with planets. The French astronomer Charles Messier discovered the first one, now known as the "Dumbbell Nebula" to amateur astronomers, in 1764. Sir William Herschel, who discovered the planet Uranus in 1781, later began a systematic survey of the entire sky and found more objects similar to the Dumbbell. Because their appearance resembled, to him, the appearance of Uranus in a telescope, he coined the term "planetary nebula," a name that has stuck ever since. Astronomers have long known that these objects are not actually related to planets, but the name has remained to confuse generations of students. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  20. Recovery of precious metals from military electronic components

    SciTech Connect

    Gundiler, I.H.; Lutz, J.D.; Neiswander, P.G.

    1996-09-01

    Sandia National Laboratories developed a process to identify and remove the hazardous sub-components from dismantled weapons components utilizing real-time radiography and abrasive water-jet cutting. The components were then crushed, granulated, screened, and separated into an aluminium and a precious-and-base-metals fraction using air-tables. Plastics were further cleaned for disposal as non- hazardous waste.

  1. Sliding-gate valve for use with abrasive materials

    DOEpatents

    Ayers, Jr., William J.; Carter, Charles R.; Griffith, Richard A.; Loomis, Richard B.; Notestein, John E.

    1985-01-01

    The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.

  2. Material removal mechanisms in abrasive vibration polishing of complex molds

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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.

  3. Attrition and abrasion models for oil shale process modeling

    SciTech Connect

    Aldis, D.F.

    1991-10-25

    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.

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

    USGS Publications Warehouse

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

    1986-01-01

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

  5. Abrasion resistant coating and method of making the same

    SciTech Connect

    Sordelet, Daniel J.; Besser, Matthew F.

    2001-06-05

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

  6. Abrasion Resistant Coating and Method of making the same

    SciTech Connect

    Sordelet, Daniel J.; Besser, Matthew F.

    1999-06-25

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

  7. 75 FR 10207 - Certain Cut-to-Length Carbon-Quality Steel Plate From the Republic of Korea: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-05

    ... ASTM A710 and A736 or their proprietary equivalents; (4) abrasion-resistant steels (i.e., USS AR 400... equivalents; (6) ball bearing steels; (7) tool steels; and (8) silicon manganese steel or silicon electric... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate From the Republic of...

  8. INTERNAL CUTTING DEVICE

    DOEpatents

    Russell, W.H. Jr.

    1959-06-30

    A device is described for removing material from the interior of a hollow workpiece so as to form a true spherical internal surface in a workpiece, or to cut radial slots of an adjustable constant depth in an already established spherical internal surface. This is accomplished by a spring loaded cutting tool adapted to move axially wherein the entire force urging the tool against the workpiece is derived from the spring. Further features of importance involve the provision of a seal between the workpiece and the cutting device and a suction device for carrying away particles of removed material.

  9. Laser cutting system

    SciTech Connect

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

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

    PubMed

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

    2010-01-01

    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

  11. Monitoring of the Abrasion Processes (by the Example of Alakol Lake, Republic of Kazakhstan)

    ERIC Educational Resources Information Center

    Abitbayeva, Ainagul; Valeyev, Adilet; Yegemberdiyeva, Kamshat; Assylbekova, Aizhan; Ryskeldieva, Aizhan

    2016-01-01

    The purpose of the study is to analyze the abrasion processes in the regions of dynamically changing Alakol lake shores. Using the field method, methods of positioning by the GPS receiver and interpretation of remote sensing data, the authors determined that abrasion processes actively contributed to the formation the modern landscape, causing the…

  12. 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 ...

  13. Process Monitoring Evaluation and Implementation for the Wood Abrasive Machining Process

    PubMed Central

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

    2010-01-01

    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

  14. Solidification/stabilization of spent abrasives and use as nonstructural concrete

    SciTech Connect

    Brabrand, D.J.; Loehr, R.C. )

    1993-01-01

    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).

  15. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Affonso Lourenco; Evren Ozbayoglu; Lei Zhou

    2002-01-30

    This is the second quarterly progress report for Year 3 of the ACTS project. It includes a review of progress made in: (1) Flow Loop development and (2) research tasks during the period of time between Oct 1, 2001 and Dec. 31, 2001. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Collection System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  16. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Evren Ozbayoglu; Lei Zhou

    2002-04-30

    This is the third quarterly progress report for Year 3 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between Jan. 1, 2002 and Mar. 31, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Separation System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 9b): ''Study of Foam Flow Behavior Under EPET Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b); (f) Development of a Safety program for the ACTS Flow Loop, progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S); and (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  17. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  18. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-01-30

    This is the second quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between October 1, 2002 and December 30, 2002. This report presents a review of progress on the following specific tasks. (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System. (b) New research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions''. (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''. (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b). (f) New Research project (Task 13): ''Study of Cuttings Transport with Foam under Elevated Pressure and Temperature Conditions''. (g) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (h) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  19. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Evren Ozbayoglu; Lei Zhou

    2002-07-30

    This is the fourth quarterly progress report for Year-3 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between April 1, 2002 and June 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Separation System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)''; (c) Research project (Task 9b): ''Study of Foam Flow Behavior Under EPET Conditions''; (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''; (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b); (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S); (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  20. Chemical-abrasion SIMS dating of zircon from the Eocene Caetano caldera, Nevada

    NASA Astrophysics Data System (ADS)

    Colgan, J.; Watts, K. E.; John, D. A.; Henry, C. D.; Coble, M. A.; Vazquez, J. A.

    2012-12-01

    The Eocene Caetano caldera in northern Nevada formed during eruption of ~1100 km3 of crystal-rich rhyolite. Miocene extension cut the caldera into a set of fault blocks that expose minor pre-caldera volcanic rocks, two units of intracaldera Caetano Tuff up to 4 km thick, ash-flow tuff feeder dikes and ring-fracture intrusions, caldera collapse breccias, and post-collapse resurgent intrusions. Single-crystal 40Ar/39Ar sanidine dates on all parts of the caldera system overlap, yielding a 34.01 ± 0.05 Ma (n=17, Fish Canyon sanidine = 28.201 Ma) age for the eruption. 40Ar/39Ar dating also documents several preceding episodes of magmatism: 35.69 ± 0.06 Ma (sanidine, n =13) rhyolite dikes in the nearby Cortez gold district, 35.21 ± 0.18 Ma (plagioclase, n=1) andesite lava underlying Caetano Tuff, and a 38.90 ± 0.11 Ma (biotite, n=1), dacite dike in the northeastern caldera wall. Extensive U-Pb SHRIMP dating of zircon from both the Cortez dikes and all phases of the Caetano system suggests continuous magmatism from 40-34 Ma. However, all samples contain at least some—sometimes many—zircons with U-Pb ages younger than the 34.0 Ma argon age. To determine if anomalously young zircon ages are due to Pb-loss, we analyzed representative samples of the upper Caetano Tuff and the Redrock Canyon resurgent pluton with and without chemical abrasion to mitigate Pb-loss. Bulk zircon separates were annealed at 850°C for 48 hours, then chemically abraded with 10:1 HF/HNO3 vapor in a Parr bomb at 225°C for 8 hours, based on protocols outlined by Mattinson (2005). Both treated and untreated zircons from the same sample were mounted in epoxy and polished to their midsections, then imaged on the SEM using BSE and CL. The SHRIMP-RG at Stanford University was used to determine U-Pb ages and trace element concentrations in single spots for ~25 to 30 individual zircons per sample, using a round-robin procedure and two zircon age standards (R33 and 080) to monitor external precision

  1. Electron Microscopy Abrasion Analysis of Candidate Fabrics for Planetary Space Suit Protective Overgarment Application

    NASA Technical Reports Server (NTRS)

    Hennessy, Mary J.

    1992-01-01

    The Electron Microscopy Abrasion Analysis of Candidate Fabrics for Planetary Space Suit Protective Overgarment Application is in support of the Abrasion Resistance Materials Screening Test. The fundamental assumption made for the SEM abrasion analysis was that woven fabrics to be used as the outermost layer of the protective overgarment in the design of the future, planetary space suits perform best when new. It is the goal of this study to determine which of the candidate fabrics was abraded the least in the tumble test. The sample that was abraded the least will be identified at the end of the report as the primary candidate fabric for further investigation. In addition, this analysis will determine if the abrasion seen by the laboratory tumbled samples is representative of actual EVA Apollo abrasion.

  2. Grain decoration in aluminum oxynitride (ALON) from polishing on bound abrasive laps

    NASA Astrophysics Data System (ADS)

    Gregg, Leslie L.; Marino, Anne E.; Hayes, Jennifer C.; Jacobs, Stephen D.

    2004-01-01

    Aluminum oxynitride (ALON) is a polycrystalline material that has proven difficult to polish due to its grain structure. Bound abrasives are an effective means for polishing ALON, and work is being done with them to obtain good surfaces, with reasonable removal rates. Laps consisting of abrasives bound in epoxy matrices were created for polishing ALON. The effects of varying abrasive type, abrasive concentration, lap shape, coolant and load were studied. Metrology procedures were developed to monitor different aspects of the grain structure and numerically evaluate grain boundary decoration. Strategies were developed to polish ALON at acceptable rates with reasonably good surface quality. Work is directed toward finding optimal bound abrasive lap formulations that can be fabricated into ring and/or contour tools for testing on CNC machining platforms.

  3. Grain decoration in aluminum oxynitride (ALON) from polishing on bound abrasive laps

    NASA Astrophysics Data System (ADS)

    Marino, Anne E.; Hayes, Jennifer; Gregg, Leslie L.; Jacobs, Stephen D.

    2003-05-01

    Aluminum oxynitride (ALON) is a material with desirable qualities for a variety of applications that has proven difficult to polish because of its grain structure. Bound abrasives may prove to be an effective means of polishing it, and work is being done with them to obtain good surfaces on ALON, with reasonable removal rates. Laps consisting of abrasives bound in epoxy matrices have been created for polishing ALON. The effects of varying abrasive type, abrasive concentration, lap shape, coolant and load are being studied. Metrology procedures are being developed to monitor different aspects of the grain structure and numerically evaluate its decoration. Strategies have been developed to polish ALON at acceptable rates with reasonably good surface quality. Work is directed toward finding optimal bound abrasive lap formulations that can be fabricated into ring and/or contour tools for testing on CNC machining platforms.

  4. Hybrid organic/inorganic coatings for abrasion resistance on plastic and metal substrates

    SciTech Connect

    Wen, J.; Jordens, K.; Wilkes, G.L.

    1996-12-31

    Novel abrasion resistant coatings have been successfully prepared by the sol-gel method. These materials are spin coated onto bisphenol-A polycarbonate, diallyl diglycol carbonate resin (CR-39) sheet, aluminum, and steel substrates and are thermally cured to obtain a transparent coating of a few microns in thickness. Following the curing, the abrasion resistance is measured and compared with an uncoated control. It was found that these hybrid organic/inorganic networks partially afford excellent abrasion resistance to the polycarbonate substrates investigated. In addition to having excellent abrasion resistance comparable to current commercial coatings, some newly developed systems are also UV resistant. Similar coating formulations applied to metals can greatly improve the abrasion resistance despite the fact that the coatings are lower in density than their substrates.

  5. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

    2003-09-30

    The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

  6. Separation and quantitation of hazardous wastes from abrasive blast media.

    PubMed

    Hwang, J Y; Jeong, M L

    2001-01-01

    A sample of glass bead abrasive blasting material (ABM) waste, received from Robins Air Force Base (Georgia), was examined to determine whether the waste could be rendered nonhazardous by separating paint contaminants from the ABM. The sample was analyzed with size distribution and toxicity characteristics leaching procedure. A Microtrac analyzer was used to measure the size of fine particles (-325 Tyler mesh), and scanning electron microscopy analysis was performed to identify the nature of the contaminants in the ABM waste. Tests using froth flotation, magnetic separation, desliming, and acid washing were conducted to develop a process for removing the contaminants. A pilot plant test using the developed process rendered 82.1% or the ABM waste material nonhazardous.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  8. Fluid bed dryer efficient with abrasive copper concentrate

    SciTech Connect

    Marczeski, C.D.; Hodel, A.E.

    1985-11-01

    Thermally efficient dryers were needed to remove 11-12% moisture from very fine (70%, -325 mesh), copper concentrate at Asarco, Inc., in Hayden, AZ. More than 128 t/hr of the wet, dust-like material produced by the copper mine's grinders had to be made bone dry (0.1% moisture) before being fed to a flash smelting furnace. Two 12 ft diam fluidized bed dryers, each with a capacity of 64 wet t/hr, were installed to dry the copper concentrate. Each dryer's push/pull air system employs a 1250 hp fluidizing air fan to provide air at 80 in (wc) static pressure. A natural gas fired heater raises the air temperature to 600/sup 0/F to dry the dense (100 lb/cu ft bulk density) ore. The dense, wet copper concentrate is fed to the dryer from the top, countercurrent to the flow of the light, dry product. Drying begins when the wet feed reaches the fluidized bed of gravel rock. Lighter, dried material is conveyed by the air back to the top of the dryer and out through a duct to the baghouse. The throughput of the dryer is determined by the wetness of the concentrate and the temperature of the fluidizing air. Asarco, Inc. has found the fluid bed drying system simple and efficient to operate. Fuel gas consumption of the dryer is on the order of 1000 cu ft/ton of wet feed. The abrasion resistant lining provided in the dryer (a hard brick lining in the rock bed zone; castable refractory in the top and in the ducting) and ceramic tiles at the inlet of the dust collector have been effective in long term operation with the highly abrasive product.

  9. Nontraditional machining; Proceedings of the Conference, Cincinnati, OH, Dec. 2, 3, 1985

    SciTech Connect

    Not Available

    1986-01-01

    Advances in cutting, grinding, and machining technology are examined in reviews and reports. Topics examined include water-jet and hydrodynamic cutting and machining, electrochemical techniques, lasers in machining, abrasive jet and flow machining, and ultrasonic machining and grinding. Consideration is given to metal cutting with abrasive water jets, the fundamental principles of fluid-jet machining, wire-cut and vertical electrical-discharge machining with computer numerical control, high-power CO/sub 2/ cutting and welding lasers and YAG laser drilling, YAG laser processing in the aircraft industry, and an ultrasonic impact grinding technique for electrode forming and redressing. Diagrams, drawings, graphs, photographs, and tables of numerical data are provided.

  10. Determination of cut front position in laser cutting

    NASA Astrophysics Data System (ADS)

    Pereira, M.; Thombansen, U.

    2016-07-01

    Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable.

  11. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira

    2000-10-30

    This is the first quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between July 14, 2000 and September 30, 2000. This report presents information on the following specific tasks: (a) Progress in Advanced Cuttings Transport Facility design and development (Task 2), (b) Progress on research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress on research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress on research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress on research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Initiate research on project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Progress on instrumentation tasks to measure: Cuttings concentration and distribution (Tasks 11), and Foam properties (Task 12), (h) Initiate a comprehensive safety review of all flow-loop components and operational procedures. Since the previous Task 1 has been completed, we will now designate this new task as: (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  12. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk, Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2002-10-30

    This is the first quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between July 1, 2002 and Sept. 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System, (b) New Research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings (Task 12), Viscosity of Foam under EPET (Task 9b). (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  13. Study on the cutting mechanism and the brittle ductile transition model of isotropic pyrolyric graphite

    NASA Astrophysics Data System (ADS)

    Wang, Minghai; Wang, Hujun; Liu, Zhonghai

    2010-12-01

    Isotropic pyrolyric graphite (IPG) is a new kind of brittle material, it can be used for sealing the aero-engine turbine shaft and the ethylene high-temperature equipment. It not only has the general advantages of ordinal carbonaceous materials such as high temperature resistance, lubrication and abrasion resistance, but also has the advantages of impermeability and machinability that carbon/carbon composite doesn't have. Therefore, it has broad prospects for development. Mechanism of brittle-ductile transition of IPG is the foundation of precision cutting while the plastic deformation of IPG is the essential and the most important mechanical behavior of precision cutting. Using the theory of strain gradient, the mechanism of this material removal during the precision cutting is analyzed. The critical cutting thickness of IPG is calculated for the first time. Furthermore, the cutting process parameters such as cutting depth, feed rate which corresponding to the scale of brittle-ductile transition deformation of IPG are calculated. In the end, based on the theory of micromechanics, the deformation behaviors of IPG such as brittle fracture, plastic deformation and mutual transformation process are all simulated under the Sih.G.C fracture criterion. The condition of the simulation is that the material under the pressure-shear loading conditions .The result shows that the best angle during the IPG precision cutting is -30°. The theoretical analysis and the simulation result are validated by precision cutting experiments.

  14. Study on the cutting mechanism and the brittle ductile transition model of isotropic pyrolyric graphite

    NASA Astrophysics Data System (ADS)

    Wang, Minghai; Wang, Hujun; Liu, Zhonghai

    2011-05-01

    Isotropic pyrolyric graphite (IPG) is a new kind of brittle material, it can be used for sealing the aero-engine turbine shaft and the ethylene high-temperature equipment. It not only has the general advantages of ordinal carbonaceous materials such as high temperature resistance, lubrication and abrasion resistance, but also has the advantages of impermeability and machinability that carbon/carbon composite doesn't have. Therefore, it has broad prospects for development. Mechanism of brittle-ductile transition of IPG is the foundation of precision cutting while the plastic deformation of IPG is the essential and the most important mechanical behavior of precision cutting. Using the theory of strain gradient, the mechanism of this material removal during the precision cutting is analyzed. The critical cutting thickness of IPG is calculated for the first time. Furthermore, the cutting process parameters such as cutting depth, feed rate which corresponding to the scale of brittle-ductile transition deformation of IPG are calculated. In the end, based on the theory of micromechanics, the deformation behaviors of IPG such as brittle fracture, plastic deformation and mutual transformation process are all simulated under the Sih.G.C fracture criterion. The condition of the simulation is that the material under the pressure-shear loading conditions .The result shows that the best angle during the IPG precision cutting is -30°. The theoretical analysis and the simulation result are validated by precision cutting experiments.

  15. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

    1999-10-15

    This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

  16. Cutting assembly. [Patent application

    DOEpatents

    Treuhaft, M.B.; Oser, M.S.

    1981-06-25

    A mining auger comprises a cutting head carried at one end of a tubular shaft and a plurality of wall segments which in a first position thereof are disposed side by side around said shaft and in a second position thereof are disposed oblique to said shaft. A vane projects outwardly from each wall segment. When the wall segments are in their first position, the vanes together form a substantially continuous helical wall. A cutter is mounted on the peripheral edge of each of the vanes. When the wall segments are in their second position, the cutters on the vanes are disposed radially outward from the perimeter of the cutting head.

  17. Radial cutting torch

    SciTech Connect

    Robertson, M.C.

    1997-01-08

    The project`s aim is to complete development of the Radial Cutting Torch, a pyrotechnic cutter, for use in all downhole tubular cutting operations in the petroleum industry. Project objectives are to redesign and pressure test nozzle seals to increase product quality, reliability, and manufacturability; improve the mechanical anchor to increase its temperature tolerance and its ability to function in a wider variety of wellbore fluids; and redesign and pressure test the RCT nozzle for operation at pressures from 10 to 20 ksi. The proposal work statement is included in the statement of work for the grant via this reference.

  18. Quantitative image analysis for evaluating the abrasion resistance of nanoporous silica films on glass

    PubMed Central

    Nielsen, Karsten H.; Karlsson, Stefan; Limbach, Rene; Wondraczek, Lothar

    2015-01-01

    The abrasion resistance of coated glass surfaces is an important parameter for judging lifetime performance, but practical testing procedures remain overly simplistic and do often not allow for direct conclusions on real-world degradation. Here, we combine quantitative two-dimensional image analysis and mechanical abrasion into a facile tool for probing the abrasion resistance of anti-reflective (AR) coatings. We determine variations in the average coated area, during and after controlled abrasion. Through comparison with other experimental techniques, we show that this method provides a practical, rapid and versatile tool for the evaluation of the abrasion resistance of sol-gel-derived thin films on glass. The method yields informative data, which correlates with measurements of diffuse reflectance and is further supported by qualitative investigations through scanning electron microscopy. In particular, the method directly addresses degradation of coating performance, i.e., the gradual areal loss of antireflective functionality. As an exemplary subject, we studied the abrasion resistance of state-of-the-art nanoporous SiO2 thin films which were derived from 5–6 wt% aqueous solutions of potassium silicates, or from colloidal suspensions of SiO2 nanoparticles. It is shown how abrasion resistance is governed by coating density and film adhesion, defining the trade-off between optimal AR performance and acceptable mechanical performance. PMID:26656260

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

    SciTech Connect

    Blau, Peter Julian; Jolly, Brian C

    2009-01-01

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

  20. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

  1. Microleakage of class V resin composite restorations after bur, air-abrasion or Er:YAG laser preparation.

    PubMed

    Corona, S A; Borsatto, M; Dibb, R G; Ramos, R P; Brugnera, A; Pécora, J D

    2001-01-01

    This in vitro study compared the microleakage of Class V resin composite restorations placed in cavities prepared with a high-speed dental bur, air-abrasion or Er:YAG laser. Twenty sound extracted human third molars were selected and randomly assigned to four equal Groups (n=10): Group I, cavities were cut by dental drill at high-speed; Group II, aluminum oxide air-abrasion was used for cavity preparation, and in Groups III and IV, cavities were prepared by Er:YAG laser. Following cavity preparation, Groups I and II were acid-etched, Group III was treated only by Er:YAG laser and Group IV was conditioned by Er:YAG laser followed by acid-etching. Cavities were restored (Single Bond + Z-100) and the teeth stored for seven days in distilled water. Then, the restorations were polished and the specimens thermocycled, immersed in a 0.2% Rhodamine solution, sectioned and analyzed for leakage at the occlusal (enamel) and cervical (dentin/cementum) interfaces using an optical microscope connected to a video camera. The images were digitized and software was utilized for microleakage assessment. Upon analyzing the results, statistically significant differences (p<0.01) between the occlusal and cervical regions for all groups was observed, and, as a rule, there was better marginal sealing at the enamel margins. The highest degree of infiltration was observed for cavities prepared and treated exclusively by Er:YAG (Group III). The other experimental groups showed statistical similarities in the amount of marginal leakage at the enamel margins. However, at the cervical margins, there was a significant difference (p<0.05) between Group I and the remaining groups. None of the techniques completely eliminated marginal microleakage at the dentin/ cementum margins.

  2. Characterization and dispersion of pollutant releases from the abrasive blasting of lead paint from steel bridges

    SciTech Connect

    Lee, M.; Rana, B.

    1999-07-01

    The characterization of airborne and spent material for abrasive blasting of steel paint was performed as part of the Environmental Impact Statement for Lead Paint Removal Operations on New York City Department of Transportation Bridges1. Laboratory tests were performed on painted steel components of the Williamsburg Bridge, to determine the sizes of particles typically released into the air as aerosol and onto the ground as bulk material, as a result of accidental releases from abrasive blasting operations. Two of the most commonly used abrasives for paint removal on steel structures, recyclable steel grit and expendable abrasives were subjected to the laboratory tests. The results of the tests were used to determine the percentage of existing paint and abrasive which becomes airborne and the resultant particle size distributions, which were employed in the air quality concentration and deposition modeling for the EIS. Particle size distributions of the airborne material indicated that the profiles of airborne lead and particulate matter have a mean particle size between 15 and 21 microns. Spent abrasives and paint chips that settle on the floor are larger in size with a mean diameter greater than 259 microns, although up to 6% of this material has a mean diameter less than 50 microns. The percentage of paint and expendable abrasives that become airborne as a result of abrasive blasting were estimated to be as high as 9.0 and 12.4%, respectively. Potential release rates were derived for total accumulation (duration of the project), annual, quarterly, 24-hour, and 1-hour time averaging periods for abrasives, lead, and other metals. Pollutant releases were simulated as individual sources at multiple release heights with the Environment Protection Agency's ISC3ST model for six representative bridges near potential places of public exposure.

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  4. Abrasive wear by coal-fueled diesel engine and related particles

    SciTech Connect

    Ives, L.K. )

    1992-09-01

    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.

  5. New vibration-assisted magnetic abrasive polishing (VAMAP) method for microstructured surface finishing.

    PubMed

    Guo, Jiang; Kum, Chun Wai; Au, Ka Hing; Tan, Zhi'En Eddie; Wu, Hu; Liu, Kui

    2016-06-13

    In order to polish microstructured surface without deteriorating its profile, we propose a new vibration-assisted magnetic abrasive polishing (VAMAP) method. In this method, magnetic force guarantees that the magnetic abrasives can well contact the microstructured surface and access the corners of microstructures while vibration produces a relative movement between microstructures and magnetic abrasives. As the vibration direction is parallel to the microstructures, the profile of the microstructures will not be deteriorated. The relation between vibration and magnetic force was analyzed and the feasibility of this method was experimentally verified. The results show that after polishing, the surface finish around microstructures was significantly improved while the profile of microstructures was well maintained.

  6. Abrasion-erosion resistance of concrete made with two aggregates, Stonewall Jackson Dam, West Virginia

    NASA Astrophysics Data System (ADS)

    Holland, T. C.

    1983-09-01

    The resistance to abrasion-erosion of two concretes made with different coarse aggregates was evaluated. The aggregates used were selected as being representative of those that may be selected for use during construction of Stonewall Jackson Dam. The two coarse aggregates were limestones from different sources. All other concrete ingredients were identical for the two mixtures. Both concretes showed very high abrasion-erosion losses when tested using the Corps of Engineers standard test method. A recommendation was made that coarse aggregates with better wear-resistant properties be selected for use in areas of the structure that may be subjected to abrasion-erosion.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  8. Plasma-polymerized coating for polycarbonate: Single-layer, abrasion resistant, and antireflection

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore

    1991-01-01

    Plasma-polymerized vinyl trimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Post-treatment of the vinyl trimethoxy silane films in an oxygen glow discharge further improved their abrasion resistance. The coatings were characterized by elemental analysis of the bulk, ESCA analysis of the surface, transmission, thickness, abrasion resistance, haze, and adhesion. This patented process is currently used by the world's largest manufacturers of non-prescription sunglasses to protect the plastic glasses from scratching and thereby to increase their useful lifetime.

  9. Electron beam cutting

    DOEpatents

    Mochel, M.E.; Humphreys, C.J.

    1985-04-02

    A method for the cutting of holes 20 Angstroms in diameter, or lines 20 Angstroms wide in a material having positive ionic conduction by the use of a focused electron probe is described. The holes and lines are stable under ambient conditions. 2 figs.

  10. Electron beam cutting

    DOEpatents

    Mochel, Margaret E.; Humphreys, Colin J.

    1985-04-02

    A method for the cutting of holes 20 Angstroms in diameter, or lines 20 Angstroms wide in a material having positive ionic conduction by the use of a focused electron probe is described. The holes and lines are stable under ambient conditions.

  11. Kids Who Cut.

    ERIC Educational Resources Information Center

    Coy, Doris Rhea; Simpson, Chris

    2002-01-01

    Regardless of whether it is cutting, burning or some other form of self-harm, self-injury is a serious problem requiring serious solutions. This article reviews the various types of self-harm, descriptions of self-mutilators, common myths about self-mutilation, and effective treatment methods. (GCP)

  12. Think before You Cut

    ERIC Educational Resources Information Center

    Pettifor, Ann

    2010-01-01

    With the main political parties set on reducing public spending, one might be forgiven for supposing that "savage" cuts are the only way forward. However, the author believes there are alternatives, and that is why public education about the financial system is so important. Today, UK is trying to clear up a mess--a mess made by the greedy and…

  13. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu; Sri Suresh Kumar Thiroveedhula

    2000-04-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with water under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic drilling fluids. Initial calibration tests have been conducted by using water. Currently, the base oil of the Petrobras synthetic drilling fluid is being tested. Foam flow experiments have been conducted. Currently, more experiments are being conducted while data are being analyzed to characterize the rheology of the foam. Cuttings transport experiments have been conducted using air, water and cuttings. Preliminary results have shown that it may not be possible to avoid cuttings bed deposition under any practical combination of air and water flow rates. Foam stability analyses have been conducted. Effects of salt and oil concentration on the foam stability have been investigated. A software for controlling the data sampling and data storage during cuttings monitoring process have been developed.

  14. Cuts endanger more services.

    PubMed

    Evans, Nick

    2016-06-01

    WHEN BARNSLEY council put out its tender for the 0-19 service last autumn, it laid down strict criteria. A ceiling of £4.8 million a year was put on any bids for the service, which incorporates school nursing teams and health visitors. That represented a cut of more than £1 million on the existing contract. PMID:27266736

  15. A Cut below

    ERIC Educational Resources Information Center

    Lum, Lydia

    2010-01-01

    Today, thousands of California students worry about vanishing college affordability and access, especially for historically under-represented and marginalized populations. The author reports on how students and faculty throughout California are grappling with the effects of draconian state cuts to postsecondary education that have topped more than…

  16. Cutting Cakes Carefully

    ERIC Educational Resources Information Center

    Hill, Theodore P.; Morrison, Kent E.

    2010-01-01

    This paper surveys the fascinating mathematics of fair division, and provides a suite of examples using basic ideas from algebra, calculus, and probability which can be used to examine and test new and sometimes complex mathematical theories and claims involving fair division. Conversely, the classical cut-and-choose and moving-knife algorithms…

  17. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Type 27A cutting-off wheels. (g) Certain internal wheels. (h) Type 4 tapered wheels. (i) Diamond wheels, except certain vitrified diamond wheels. (j) Modified Types 6 and 11 wheel (terrazzo)—blotters... internal wheels. (viii) Type 4 tapered wheels. (ix) Diamond wheels, except certain vitrified diamond...

  18. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-04-30

    Experiments on the flow loop are continuing. Improvements to the software for data acquisition are being made as additional experience with three-phase flow is gained. Modifications are being made to the Cuttings Injection System in order to improve control and the precision of cuttings injection. The design details for a drill-pipe Rotation System have been completed. A US Patent was filed on October 28, 2002 for a new design for an instrument that can generate a variety of foams under elevated pressures and temperatures and then transfer the test foam to a viscometer for measurements of viscosity. Theoretical analyses of cuttings transport phenomena based on a layered model is under development. Calibrations of two nuclear densitometers have been completed. Baseline tests have been run to determine wall roughness in the 4 different tests sections (i.e. 2-in, 3-in, 4-in pipes and 5.76-in by 3.5-in annulus) of the flow loop. Tests have also been conducted with aerated fluids at EPET conditions. Preliminary experiments on the two candidate aqueous foam formulations were conducted which included rheological tests of the base fluid and foam stability reports. These were conducted after acceptance of the proposal on the Study of Cuttings Transport with Foam Under Elevated Pressure and Elevated Temperature Conditions. Preparation of a test matrix for cuttings-transport experiments with foam in the ACTF is also under way. A controller for instrumentation to measure cuttings concentration and distribution has been designed that can control four transceivers at a time. A prototype of the control circuit board was built and tested. Tests showed that there was a problem with radiated noise. AN improved circuit board was designed and sent to an external expert to verify the new design. The new board is being fabricated and will first be tested with static water and gravel in an annulus at elevated temperatures. A series of viscometer tests to measure foam properties have

  19. Surface roughness and gloss of current CAD/CAM resin composites before and after toothbrush abrasion.

    PubMed

    Koizumi, Hiroyasu; Saiki, Osamu; Nogawa, Hiroshi; Hiraba, Haruto; Okazaki, Tomoyo; Matsumura, Hideo

    2015-01-01

    The purpose of this study was to evaluate the gloss and surface roughness behaviors of newly developed CAD/CAM composite blocks with different filler contents and characteristics. The gloss and surface roughness were quantified before and after a toothbrush dentifrice abrasion test; the results were compared to the gloss and surface roughness of a ceramic CAD/CAM block. Knoop hardness was determined before abrasion test. The results were analyzed by ANOVA, Tukey HSD, and Dunnett t test (p<0.05). The rank order of Knoop hardness was as follows: Vita Mark II>Vita Enamic>Gradia block>Shofu Block HC, Lava Ultimate≥Katana Avencia block≥Cerasmart. After toothbrush abrasion, a significant difference in the gloss unit was detected between the Shofu Block HC material and the ceramic block. The Ra and Rz of the Cerasmart and Shofu Block HC materials were significantly larger than those of the ceramic block after toothbrush abrasion.

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  1. Summary of Rock Abrasion Tool (RAT) Results Pertinent to the Mars Exploration Rover Science Data Set

    NASA Astrophysics Data System (ADS)

    Bartlett, P. W.; Carlson, L. E.; Chu, P. C.; Davis, K. R.; Gorevan, S.; Kusack, A. G.; Myrick, T. M.; Wilson, J. J.

    2005-03-01

    The Rock Abrasion Tool (RAT) serves as the sample preparation device on the Mars Exploration Rover payload, grinding a circular spot on the order of millimeters deep into a rock face to remove surface layers, preparing the rock for observation.

  2. Abrasion resistance of biaxially oriented polypropylene films coated with nanocomposite hard coatings

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

    2013-11-01

    KMnO4-treated, functionalized, biaxially oriented polypropylene (BOPP) films coated with nano-silica hybrid material were synthesized. The abrasion resistance of the films was examined using a reciprocating fabric abrasion tester. Functional groups were confirmed by Fourier-transform infrared spectroscopy. Contact angle measurements were performed on the BOPP film surface to quantify the effectiveness of the functionalization. Results indicate that the abrasion resistance and roughness of the composite film were significantly affected by the modification of the BOPP film. Water surface contact angle of the modified BOPP films decreased from 90.1° to 71.4°,when KMnO4 concentration increased from 0 M to 0.25 M. Wettability of the BOPP films clearly improved after KMnO4 treatment. Abrasion resistance of the functionalized films coated with hybrid materials improved by 27.4% compared with that of the original film.

  3. Recent Results from the Mars Exploration Rover Rock Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Cohen, J.; Paulsen, G.; Davis, K.; Gorevan, S.; Zacny, K.

    2009-12-01

    The Rock Abrasion Tool (RAT) serves as the sample preparation device on the Mars Exploration Rovers (MER) science payload. The RAT grinds Martian rock in a cylindrical volume, 45 mm in diameter and to a depth of up to 10 mm. This grinding action is intended to remove the altered outer layers of rock as well as overlying surface fines in preparation for imaging and spectral observations. In addition to acting as a facilitator for other instruments in the MER payload, RAT telemetry acquired during grinding may be used to assess the physical properties of the rocks that it grinds. RAT instruments on both Spirit and Opportunity have continued to operate and return useful data since 2004, despite minor problems that have recently occurred. The RAT on Spirit has recently been used for a purpose outside its original design capabilities: brushing away thin layers of loose soil without solid rock underneath. By progressing into the soil a few millimeters at a time, the RAT has been instrumental in helping to reveal the stratigraphy of this soft material. These results have helped in assessing soil properties and in turn will facilitate extrication of Spirit from its current location. Recent results from the Mars Exploration Rovers are presented along with data from laboratory RAT testing.

  4. Recent Results from the Mars Exploration Rover Rock Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Kusack, A.; Zacny, K.; Gorevan, S.

    2008-12-01

    The Rock Abrasion Tool (RAT) serves as the sample preparation device on the Mars Exploration Rovers (MER) science payload. The RAT grinds a circular area 45 millimeter in diameter and to a depth of 0-15 mm into Martian rock. This is intended to remove the altered outer layers of rock as well as overlying surface fines in preparation for imaging and spectral observations. In addition to acting as a facilitator for other instruments, RAT telemetry acquired during grinding may be used to assess the physical properties of the rocks that it grinds. The most direct rock measurement extractable from the RAT grinding process is the energy expended per unit of rock volume removed. This has been termed the RAT Specific Grind Energy (SGE) and in terms of rock bulk physical properties, correlates roughly with unconfined compressive strength. Recent results from the Mars Exploration Rovers will be presented as will comparisons between Earth rocks and Martian rocks in terms of their SGEs and other physical properties. Although SGE is an uncommon metric for rock physical properties, the SGE calculated from the RAT engineering data, and linked with data from other instruments in the payload, represent the most comprehensive database yet created of the physical properties of Martian rocks. RAT SGE continues to be helpful in understanding the geologic history of Mars and will be of great value in instrument design for future Mars missions.

  5. Recent Results from the Mars Exploration Rover Rock Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Kusack, A.; Zacny, K.; Gorevan, S.

    2007-12-01

    The Rock Abrasion Tool (RAT) serves as the sample preparation device on the Mars Exploration Rovers (MER) science payload. The RAT grinds a circular area 45 millimeter in diameter and to a depth of 0-15 mm into Martian rock. This is intended to remove the altered outer layers of rock as well as overlying surface fines in preparation for imaging and spectral observations. In addition to acting as a facilitator for other instruments, RAT telemetry acquired during grinding may be used to assess the physical properties of the rocks that it grinds. The most direct rock measurement extractable from the RAT grinding process is the energy expended per unit of rock volume removed. This has been termed the RAT Specific Grind Energy (SGE) and in terms of rock bulk physical properties, correlates roughly with unconfined compressive strength. Recent results from the Mars Exploration Rovers will be presented as will comparisons between Earth rocks and Martian rocks in terms of their SGEs and other physical properties. Although SGE is an uncommon metric for rock physical properties, the SGE calculated from the RAT engineering data, and linked with data from other instruments in the payload, represent the most comprehensive database yet created of the physical properties of Martian rocks. RAT SGE continues to be helpful in understanding the geologic history of Mars and will be of great value in instrument design for future Mars missions.

  6. Experimental investigation of the abrasive crown dynamics in orbital atherectomy.

    PubMed

    Zheng, Yihao; Belmont, Barry; Shih, Albert J

    2016-07-01

    Orbital atherectomy is a catheter-based minimally invasive procedure to modify the plaque within atherosclerotic arteries using a diamond abrasive crown. This study was designed to investigate the crown motion and its corresponding contact force with the vessel. To this end, a transparent arterial tissue-mimicking phantom made of polyvinyl chloride was developed, a high-speed camera and image processing technique were utilized to visualize and quantitatively analyze the crown motion in the vessel phantom, and a piezoelectric dynamometer measured the forces on the phantom during the procedure. Observed under typical orbital atherectomy rotational speeds of 60,000, 90,000, and 120,000rpm in a 4.8mm caliber vessel phantom, the crown motion was a combination of high-frequency rotation at 1000, 1500, and 1660.4-1866.1Hz and low-frequency orbiting at 18, 38, and 40Hz, respectively. The measured forces were also composed of these high and low frequencies, matching well with the rotation of the eccentric crown and the associated orbital motion. The average peak force ranged from 0.1 to 0.4N at different rotational speeds. PMID:27160429

  7. Plasma polymerized coating for polycarbonate: single layer, abrasion resistant, and antireflection.

    PubMed

    Wydeven, T

    1977-03-01

    Plasma polymerized vinyltrimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Posttreatment of the vinyltrimethoxy silane films in an oxygen glow discharge further improved the abrasion resistance. ESCA (electron spectroscopy for chemical analysis) and ir transmission spectra of some films were recorded, and an elemental analysis of the films was obtained.

  8. Patient preference: conventional rotary handpieces or air abrasion for cavity preparation.

    PubMed

    Malmström, Hans S; Chaves, Yvette; Moss, Mark E

    2003-01-01

    It has been suggested that patients should accept the use of the air abrasion technique over the conventional handpiece due to the reduced need for anesthesia. Technologies for both air abrasion and the conventional rotary handpiece have, in recent decades, seen major improvements, but there are no recent scientific publications that evaluate the patient's preference for these two technologies when performing a cavity preparation. This study determined the patient's preference for air abrasion or the rotary handpiece for removing occlusal fissure carious lesions in mandibular premolars. Ten healthy subjects 18 years of age or older were recruited from the General Dentistry Clinic of the University of Rochester Eastman Dental Center, with fissure caries at a DEJ depth of similar size (determined by radiographs and clinical examination) in any two mandibular premolars in opposite quadrants. Within each subject, the two methods of caries removal were randomly assigned. In one premolar, air abrasion was used for cavity preparation, and in the other premolar, a conventional rotary handpiece was used. At each visit prior to treatment, the patients were instructed to complete the Emotional Status (ES) questionnaire (SUNY University at Buffalo Craniofacial Pain Clinic) to assess differences in their emotional status between appointments. At each appointment, when the restorative treatment was completed, patients were instructed to rate their pain on the Visual Analogue Scale (VAS). A technique preference questionnaire was given after the second appointment. The subjects rated the perception of pain as significantly lower (p < 0.05) when using air abrasion (6.0 mm versus 29.6 mm). All of the patients preferred air abrasion over conventional rotary handpieces. None of the patients required anesthesia and there was no indication that the emotional status influenced the result. Air abrasion was the preferred method of cavity preparation when removing fissural caries in

  9. Three-body abrasive wear characteristics under reciprocating motion of CFRP in vibrating environment

    SciTech Connect

    Teraoka, Sadakazu; Ishikawa, Ken-ichi; Nakagawa, Tatsuo

    1996-12-31

    Carbon fiber reinforced plastics (CFRP) has been widely used in industry because of their attractive mechanical characteristics. Such CFRP parts are invariably subjected to three-body wear due to small indentations and machine vibrations. In this study, the wear characteristics under the three-body condition and the abrasive wear of CFRP were investigated by using a vibrating environment and silicon carbide abrasive grains.

  10. Plasma polymerized coating for polycarbonate - Single layer, abrasion resistant, and antireflection

    NASA Technical Reports Server (NTRS)

    Wydeven, T.

    1977-01-01

    Plasma polymerized vinyltrimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Posttreatment of the vinyltrimethoxy silane films in an oxygen glow discharge further improved the abrasion resistance. ESCA (electron spectroscopy for chemical analysis) and IR transmission spectra of some films were recorded, and an elemental analysis of the films was obtained.

  11. Laser cutting nozzle

    DOEpatents

    Ramos, Terry J.

    1984-01-01

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece. BACKGROUND OF THE INVENTION

  12. Laser cutting nozzle

    DOEpatents

    Ramos, T.J.

    1982-09-30

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece.

  13. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

    2000-07-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

  14. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-07-30

    This Quarter has been divided between running experiments and the installation of the drill-pipe rotation system. In addition, valves and piping were relocated, and three viewports were installed. Detailed design work is proceeding on a system to elevate the drill-string section. Design of the first prototype version of a Foam Generator has been finalized, and fabrication is underway. This will be used to determine the relationship between surface roughness and ''slip'' of foams at solid boundaries. Additional cups and rotors are being machined with different surface roughness. Some experiments on cuttings transport with aerated fluids have been conducted at EPET. Theoretical modeling of cuttings transport with aerated fluids is proceeding. The development of theoretical models to predict frictional pressure losses of flowing foam is in progress. The new board design for instrumentation to measure cuttings concentration is now functioning with an acceptable noise level. The ultrasonic sensors are stable up to 190 F. Static tests with sand in an annulus indicate that the system is able to distinguish between different sand concentrations. Viscometer tests with foam, generated by the Dynamic Test Facility (DTF), are continuing.

  15. Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders.

    PubMed

    Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2012-01-23

    Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St(Abr)) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The St(Abr) number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of St(Abr) was demonstrated.

  16. A light-scattering study of Al2O3 abrasives of various grit sizes

    NASA Astrophysics Data System (ADS)

    Heinson, Yuli W.; Chakrabarti, Amitabha; Sorensen, Christopher M.

    2016-09-01

    We report light scattering phase function measurements for irregularly shaped Al2O3 abrasive powders of various grit sizes. Q-space analysis is applied to the angular scattering to reveal a forward scattering regime, Guinier regime, power law regime with quantifiable exponents, and an enhanced backscattering regime. The exponents of the power laws for Al2O3 abrasives decrease with increasing internal coupling parameter ρ ‧ , which is in agreement with previous observations for other irregular particles. Unlike other dust particles previously studied showing single power laws under Q-space analysis, the largest three abrasives, for which ρ ‧ ≳ 100 , showed a kink in the power law, which is possibly due to the higher degree of symmetry for the abrasives than for all the particles studied previously. Direct comparison of the 1200, 1000, and 800 grit abrasive scattering to scattering by corresponding spheres shows that the scatterings approximately coincide at the spherical particle qR ≃ ρ ‧ crossover point. Furthermore, the scattering at the maximum qR = 2 kR by the irregularly shaped abrasives is close to the geometric centers of the glories of the spheres.

  17. Reagan Administration Prepares Budget Cuts.

    ERIC Educational Resources Information Center

    Norman, Colin

    1981-01-01

    Describes tentative federal budget cuts affecting science education in the National Science Foundation, National Aeronautics and Space Administration, Department of Energy, National Institutes of Health, and the specific areas these budget cuts will affect. (DS)

  18. Dealing with Cuts (For Parents)

    MedlinePlus

    ... pus. For Bleeding From a Large Cut or Laceration: Wash the wound thoroughly with water. This will ... immediate medical attention for all large cuts or lacerations, or if: you're unable to stop the ...

  19. The Mars Environmental Compatibility Assessment MECA Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J.; Meloy, T. P.; Cobbly, T.

    1999-09-01

    The Mars Environmental Compatibility Assessment (MECA) experiment, an instrument suite to be flown on Mars Surveyor 2001, will include a tool for doing simple mineralogical scratch and streak tests on particles from the Martian regolith. The Abrasion Tool will be applied to particles that adhere to highly polished substrates of various hardnesses. Granular soil components will be subjected to a compressive force of about 3 N using a leaf spring. The spring will be applied with a paraffin actuator capable of a 0.76 mm throw to achieve a maximum displacement of about 7.5 mm at the tip of the tool. The pressure per grain will be dependent on the grain size, the number of grains that adhere to the substrate and the number of grains in compression. The pressure per particle is expected to be on the order of 100 MPa - 1 GPa. The MECA sample wheel containing the substrates will be rotated after the particles are placed in compression to produce scratches or pits. A primary goal of the Abrasion Tool is to identify quartz (Mohs' hardness = 7) using substrates of varying hardnesses. Quartz is considered hazardous to future human explorers of Mars because it can cause silicosis of the lungs if it is of respirable size. It is also hazardous to machinery, structures, and space suits because of its ability to abrade and scratch surfaces. Since large quantities of minerals harder than quartz are not expected, any scratches produced on polished quartz substrates might be reasonably attributed to quartz particles, although there may be minerals such as impact metamorphic diamond in the soils. Careful calibration of the tool will be necessary to ensure that grains are not overloaded; for example, a steel ball pressed into glass will produce a Hertzian fracture, even though it is softer than glass. Other minerals, such as magnetite (Mohs'hardness = 6.5) have been shown to scratch glass ceramics such as Zerodur (Mohs' hardness = 6.5). Thus, minerals can be differentiated: note that

  20. The Mars Environmental Compatibility Assessment MECA Abrasion Tool

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J.; Meloy, T. P.; Cobbly, T.

    1999-01-01

    The Mars Environmental Compatibility Assessment (MECA) experiment, an instrument suite to be flown on Mars Surveyor 2001, will include a tool for doing simple mineralogical scratch and streak tests on particles from the Martian regolith. The Abrasion Tool will be applied to particles that adhere to highly polished substrates of various hardnesses. Granular soil components will be subjected to a compressive force of about 3 N using a leaf spring. The spring will be applied with a paraffin actuator capable of a 0.76 mm throw to achieve a maximum displacement of about 7.5 mm at the tip of the tool. The pressure per grain will be dependent on the grain size, the number of grains that adhere to the substrate and the number of grains in compression. The pressure per particle is expected to be on the order of 100 MPa - 1 GPa. The MECA sample wheel containing the substrates will be rotated after the particles are placed in compression to produce scratches or pits. A primary goal of the Abrasion Tool is to identify quartz (Mohs' hardness = 7) using substrates of varying hardnesses. Quartz is considered hazardous to future human explorers of Mars because it can cause silicosis of the lungs if it is of respirable size. It is also hazardous to machinery, structures, and space suits because of its ability to abrade and scratch surfaces. Since large quantities of minerals harder than quartz are not expected, any scratches produced on polished quartz substrates might be reasonably attributed to quartz particles, although there may be minerals such as impact metamorphic diamond in the soils. Careful calibration of the tool will be necessary to ensure that grains are not overloaded; for example, a steel ball pressed into glass will produce a Hertzian fracture, even though it is softer than glass. Other minerals, such as magnetite (Mohs'hardness = 6.5) have been shown to scratch glass ceramics such as Zerodur (Mohs' hardness = 6.5). Thus, minerals can be differentiated: note that

  1. The Mars Environmental Compatibility Assessment (MECA) Abrasion Tool

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J. R.; Meloy, T. P.

    1999-01-01

    The Mars Environmental Compatibility Assessment (MECA) experiment, an instrument suite to be flown on Mars Surveyor 2001, will include a tool for doing simple mineralogical scratch and streak tests on particles from the Martian regolith. The Abrasion Tool will be applied to particles that adhere themselves to highly polished substrates of various hardnesses. Granular soil components will be subjected to a compressive force of about 3 N using a leaf spring. The spring will be applied with a paraffin actuator capable of a 0.76 mm throw to achieve a maximum displacement of about 7.5 mm at the tip of the tool. The pressure per grain will be dependent on the grain size, the number of grains that adhere to the substrate and the number of grains in compression. The pressure per particle is expected to be on the order of 100 MPa - 1 GPa. The MECA sample wheel containing the substrates will be rotated after the particles are placed in compression to produce scratches or pits. A primary goal of the Abrasion Tool is to identify quartz (Mohs' hardness = 7) using substrates of varying hardnesses. Quartz is considered hazardous to future human explorers of Mars because it can cause silicosis of the lungs if it is of respirable size. It is also hazardous to machinery, structures, and space suits because of its ability to abrade and scratch surfaces. Since large quantities of minerals harder than quartz are not expected, any scratches produced on polished quartz substrates might be reasonably attributed to quartz particles, although there may be minerals such as impact metamorphic diamond in the soils. Careful calibration of the tool will be necessary to ensure that grains are not overloaded; for example, a steel ball pressed into glass will produce a Hertzian fracture, even though it is softer than glass. Other minerals, such as magnetite (Mohs' hardness = 6.5) have been shown to scratch glass ceramics such as Zerodur (Mohs' hardness = 6.5). Thus, minerals can be differentiated

  2. Mechanics of the pad-abrasive-wafer contact in chemical mechanical polishing

    NASA Astrophysics Data System (ADS)

    Bozkaya, Dincer

    2009-12-01

    In chemical mechanical polishing (CMP), a rigid wafer is forced on a rough, elastomeric polishing pad, while a slurry containing abrasive particles flows through the interface. The applied pressure on the wafer is carried partially by the 2-body pad-wafer contact (direct contact) and partially by the 3-body contact of pad, wafer and abrasive particles ( particle contact). The fraction of the applied pressure carried by particle contacts is an important factor affecting the material removal rate (MRR) as the majority of the material is removed by the abrasive particles trapped between the pad asperities and the wafer. In this thesis, the contact of a rough, deformable pad and a smooth, rigid wafer in the presence of rigid abrasive particles at the contact interface is investigated by using contact mechanics and finite element (FE) modeling. The interactions between the pad, the wafer and the abrasive particles are modeled at different scales of contact, starting from particle level interactions, and gradually expanding the contact scale to the multi-asperity contact of pad and wafer. The effect of surface forces consisting of van der Waals and electrical double layer forces acting between the wafer and the abrasive particles are also investigated in this work. The wear rate due to each abrasive particle is calculated based on the wafer-abrasive particle contact force, and by considering adhesive and abrasive wear mechanisms. A passivated layer on the wafer surface with a hardness and thickness determined by the chemical effects is modeled, in order to characterize the effect of chemical reactions between slurry and wafer on the MRR. The model provides accurate predictions for the MRR as a function of pad related parameters; pad elastic modulus, pad porosity and pad topography, particle related parameters; particle size and concentration, and slurry related parameters; slurry pH, thickness and hardness of the passivated surface layer of wafer. A good qualitative

  3. Using frictional power to model LSST removal with conventional abrasives

    NASA Astrophysics Data System (ADS)

    Allen, Richard G.; Hubler, William H.

    2015-08-01

    The stressed lap on the Large Polishing Machine (LPM) at the University of Arizona Richard F. Caris Mirror Lab has recently been used to polish the M1 and M3 surfaces of the 8.4-m mirror for the Large Synoptic Survey Telescope (LSST). Loadcells in the three 4-bar links that connect this lap to the spindle of the machine allow the translational forces and torque on the lap to be measured once a second. These force readings and all other available machine parameters are recorded in history files that can be used to create a 2D removal map from one or more polishing runs. While the Preston equation has been used for many years to predict removal in a conventional polishing process, we have adopted a new equation that assumes that removal is proportional to the energy that is transferred from the lap to the substrate via friction. Specifically, the instantaneous removal rate at any point is defined to be the product of four parameters - an energy conversion factor which we call the Allen coefficient, the coefficient of friction, the lap pressure, and the speed of the lap. The Allen coefficient is the ratio of volumetric removal to frictional energy for a particular combination of pad material, abrasive, and substrate. Because our calculations take into account changes in the coefficient of friction between the lap and mirror, our 2D removal maps usually correlate well with optical data. Removal maps for future polishing strokes are created in simulations that track the position and speed of individual lap pads.

  4. Drilling cost-cutting

    SciTech Connect

    Capuano, L.E. Jr.

    1996-12-31

    This presentation by Louis E. Capuano, Jr., President, ThermaSource, Inc., discusses cost-cutting in the drilling phase of geothermal energy exploration and production. All aspects of a geothermal project including the drilling must be streamlined to make it viable and commercial. If production could be maximized from each well, there would be a reduction in drilling costs. This could be achieved in several ways, including big hole and multi-hole completion, directional drilling, better knowledge of the resource and where to penetrate, etc.

  5. Cutting the Cord

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This animation shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting off the front lander petal. Before this crucial turn could take place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

  6. Cross-Cutting Faults

    NASA Technical Reports Server (NTRS)

    2005-01-01

    16 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows cross-cutting fault scarps among graben features in northern Tempe Terra. Graben form in regions where the crust of the planet has been extended; such features are common in the regions surrounding the vast 'Tharsis Bulge' on Mars.

    Location near: 43.7oN, 90.2oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  7. Cutting the Cord-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This animation shows the view from the rear hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting from the front lander petal. Before this crucial turn took place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

  8. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-07-31

    We have tested the loop elevation system. We raised the mast to approximately 25 to 30 degrees from horizontal. All went well. However, while lowering the mast, it moved laterally a couple of degrees. Upon visual inspection, severe spalling of the concrete on the face of the support pillar, and deformation of the steel support structure was observed. At this time, the facility is ready for testing in the horizontal position. A new air compressor has been received and set in place for the ACTS test loop. A new laboratory has been built near the ACTS test loop Roughened cups and rotors for the viscometer (RS300) were obtained. Rheologies of aqueous foams were measured using three different cup-rotor assemblies that have different surface roughness. The relationship between surface roughness and foam rheology was investigated. Re-calibration of nuclear densitometers has been finished. The re-calibration was also performed with 1% surfactant foam. A new cuttings injection system was installed at the bottom of the injection tower. It replaced the previous injection auger. A mechanistic model for cuttings transport with aerated mud has been developed. Cuttings transport mechanisms with aerated water at various conditions were experimentally investigated. A total of 39 tests were performed. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. Results from the ultrasonic monitoring system indicated that we could distinguish between different sand levels. We also have devised ways to achieve consistency of performance by securing the sensors in the caps in exactly the same manner as long as the sensors are not removed from the caps. A preliminary test was conducted on the main flow loop at 100 gpm flow rate and 20 lb/min cuttings injection rate. The measured bed thickness using the ultrasonic method showed a satisfactory agreement with nuclear densitometer readings. Thirty different data points were collected after the test

  9. Photochemical cutting of fabrics

    DOEpatents

    Piltch, Martin S.

    1994-01-01

    Apparatus for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged.

  10. Investigating selective transport and abrasion on an alluvial fan using quantitative grain size and shape analysis

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Selective sorting and abrasion are the two major fluvial processes that are attributed to the downstream fining of sediments in rivers and alluvial fans. Selective transport is the process by which smaller grains are preferentially transported downstream while larger grains are deposited closer to the source. Abrasion is defined by the production of fine sediments and sand that occurs by saltation of gravel, where particle-to-particle collisions supply the energy required to break apart grains. We hypothesize that abrasion results in the gradual fining of large grains and the production of fine sands and silts, while sorting accounts for the differences in transport of these two grain-size fractions produced from abrasion, thereby creating the abrupt gravel-sand transition observed in many channel systems. In this research, we explore both selective transport and abrasion processes on the Dog Canyon alluvial fan near Alamogordo, New Mexico. We complete an extensive grain size analysis down the main channel of the fan employing an image-based technique that utilizes an autocorrelation process. We also characterize changes in grain shape using standard shape parameters, as well as Fourier analysis, which allows the study of contributions of grain roughness on a variety of length scales. Sorting appears to dominate the upper portion of the fan; the grain-size distribution narrows moving downstream until reaching a point of equal mobility, at which point sorting ceases. Abrasion exerts a subtle but persistent effect on grains during transport down the fan. Shape analysis reveals that particles become more rounded by the removal of small-scale textural features, a process that is expected to only modestly influence grain size of gravel, but should produce significant quantities of sand. This study provides a better understanding of the importance of grain abrasion and sorting on the downstream fining of channel grains in an alluvial fan, as well as an improved knowledge

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

    PubMed Central

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

    2013-01-01

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

  12. Combined effect of end-rounded versus tapered bristles and a dentifrice on plaque removal and gingival abrasion.

    PubMed

    Caporossi, Leonardo Stephan; Dutra, Danilo Antonio Milbradt; Martins, Maritieli Righi; Prochnow, Emilia Pithan; Moreira, Carlos Heitor Cunha; Kantorski, Karla Zanini

    2016-01-01

    Two previous clinical studies evaluated the effect of end-rounded versus tapered bristles of soft manual brushes on the removal of plaque and gingival abrasion. However, the combined effect of an abrasive dentifrice on these outcomes has yet to be understood. The purpose of the present study was to compare the incidence of gingival abrasion and the degree of plaque removal obtained after the use of toothbrushes with tapered or end-rounded bristles in the presence or absence of an abrasive dentifrice. The study involved a randomized, single-blind, crossover model (n = 39) with a split-mouth design. Subjects were instructed to refrain from performing oral hygiene procedures for 72 hours. Quadrants were randomized and subjects brushed with both types of toothbrushes using a dentifrice (relative dentin abrasion = ± 160). Plaque and gingival abrasion were assessed before and after brushing. After 7 days, the experiment was repeated without the dentifrice. The average reduction in plaque scores and the average increase in the number of abrasion sites were assessed by repeated-measures ANOVA and Bonferroni's post-hoc tests. End-rounded bristles removed significantly more plaque than tapered bristles, regardless of the use of a dentifrice. The dentifrice did not improve plaque removal. In the marginal area (cervical free gingiva), no difference in the incidence of gingival abrasion was detected between toothbrush types when used with a dentifrice (p ≥ 0.05). However, the dentifrice increased the incidence of abrasion (p < 0.001), irrespective of the toothbrush type tested. End-rounded bristles therefore removed plaque more effectively without causing a higher incidence of gingival abrasion when compared with tapered bristles. An abrasive dentifrice can increase the incidence of abrasion, and should be used with caution by individuals who are at risk of developing gingival recession. PMID:26981758

  13. The effect of heat treatment on the gouging abrasion resistance of alloy white cast irons

    NASA Astrophysics Data System (ADS)

    Are, I. R. S.; Arnold, B. K.

    1995-02-01

    A series of heat treatments was employed to vary the microstructure of four commercially important alloy white cast irons, the wear resistance of which was then assessed by the ASTM jaw-crusher gouging abrasion test. Compared with the as-cast condition, standard austenitizing treatments produced a substantial increase in hardness, a marked decrease in the retained aus-tenite content in the matrix, and, in general, a significant improvement in gouging abrasion resistance. The gouging abrasion resistance tended to decline with increasing austenitizing tem-perature, although the changes in hardness and retained austenite content varied, depending on alloy composition. Subcritical heat treatment at 500 ° following hardening reduced the retained austenite content to values less than 10 pct, and in three of the alloys it caused a significant fall in both hardness and gouging abrasion resistance. The net result of the heat treatments was the development of optimal gouging abrasion resistance at intermediate levels of retained aus-tenite. The differing responses of the alloys to both high-temperature austenitizing treatments and to subcritical heat treatments at 500 ° were related to the effects of the differing carbon and alloying-element concentrations on changes in the M s temperature and secondary carbide precipitation.

  14. Effect of Internal Limiting Membrane Abrasion on Retinal Tissues in Macular Holes

    PubMed Central

    Almeida, David R. P.; Chin, Eric K.; Tarantola, Ryan M.; Folk, James C.; Boldt, H. Culver; Skeie, Jessica M.; Mullins, Robert F.; Russell, Stephen R.; Mahajan, Vinit B.

    2015-01-01

    Purpose. The purpose of this study was to identify the structural and histological effects of a Tano diamond-dusted membrane scraper (DDMS) on the retinal surface after internal limiting membrane (ILM) abrasion in macular hole surgery. Methods. Institutional experimental study was performed in 11 eyes. All eyes underwent ILM abrasion in the operating room with a DDMS for macular hole repair as an alternative to traditional ILM peeling. Three human donor eyes underwent an identical procedure in the laboratory. Retinal tissues were removed by ILM abrasion with a DDMS during vitrectomy for macular hole repair and retinal tissues remaining in human donor eyes. Main outcome measures were microscopic and immunohistological characteristics of instrument tip tissues and retinal structure after ILM abrasion. Results. The tips of the Tano DDMS showed evidence of cellular membranes and ILM removal. The retinas showed distinct areas of lamellar ILM removal without penetration of the retinal nerve fiber layer (RNFL). Conclusions. Application of the Tano DDMS instrument is sufficient to remove membranes from the surface of the ILM and layers of the ILM without disruption of the underlying RNFL. Internal limiting membrane abrasion can be a useful and effective alternative to complete ILM removal for macular surgery. PMID:26024069

  15. Effect of carbonitride precipitates on the abrasive wear behaviour of hardfacing alloy

    NASA Astrophysics Data System (ADS)

    Yang, Ke; Yu, Shengfu; Li, Yingbin; Li, Chenglin

    2008-06-01

    Hardfacing alloy of martensitic stainless steel expect higher abradability to be achieved through the addition of nitrogen being provided by the fine scale precipitation of complex carbonitride particles. Niobium and titanium as the most effective carbonitride alloying elements were added in the Fe-Cr13-Mn-N hardfacing alloy to get carbonitride precipitates. Carbonitride was systematically studied by optical microscopy, scanning electronic microscopy and energy spectrum analysis. Abrasive wear resistance of hardfacing alloy in as-welded and heat-treated conditions was tested by using the belt abrasion test apparatus where the samples slide against the abrasive belt. It is found that carbonitride particles in the hardfacing alloy are complex of Cr, Ti and Nb distributing on the grain boundary or matrix of the hardfacing alloy with different number and size in as-welded and heat-treated conditions. A large number of carbonitrides can be precipitated with very fine size (nanoscale) after heat treatment. As a result, the homogeneous distribution of very fine carbonitride particles can significantly improve the grain-abrasion wear-resisting property of the hardfacing alloy, and the mass loss is plastic deformation with minimum depth of grooving by abrasive particles and fine delamination.

  16. The effect of erosion and abrasion on surface properties of composite resin

    NASA Astrophysics Data System (ADS)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Munteanu, A.; Balan, A.; Iovan, G.

    2016-06-01

    The aim of the study was to evaluate the surface roughness of two commercial composite resins submitted to erosive attack, to abrasive wear and to association of erosive and abrasive challenge. Standardized samples of G-snial anterior (GC Company) and Essentia (GC Company) composite resins were randomly split in 6 groups. In group 1 the samples were maintained in artificial saliva until the evaluation of surface roughness. In group 2 the samples were submitted only to erosive attack, in group 3 only to abrasive challenge and in groups 4,5, and 6 the erosive attack was followed by abrasive challenge immediately (group 4), 30 minutes after the erosive attack (group 5) and one hour after the erosive attack (group 6). The specimens were evaluated using surface roughness measuring tester SJ-210 (Mitutoyo Corporation, Japan) and the mean surface roughness values (Ra, μm) of each specimen were registered. A significantly increase of both composite resins surface roughness was recorded after erosive attack and abrasive challenge. Toothbrushing 60 minutes after acidic contact determined no significant differences in surface roughness of composite resins.

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

    PubMed Central

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

    2013-01-01

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

  18. Assessment of the abrasion potential of pesticide-treated seeds using the Heubach test

    PubMed Central

    Zwertvaegher, Ingrid K. A.; Foqué, Dieter; Devarrewaere, Wouter; Verboven, Pieter; Nuyttens, David

    2016-01-01

    ABSTRACT During sowing of pesticide-treated seeds, pesticide-laden dust and abraded seed particles may be emitted to the environment, possibly leading to environmental contamination and posing health risks. In many countries there is currently no legislation concerning the acceptable amount of dust of treated seeds. This study aimed to gain insight in the abrasion potential of available pesticide-treated seeds and its associated factors. The abrasion potential of 45 seed samples of 7 different species (viz. sugar beet, oat, barley, wheat, spelt, pea, and maize) was determined using the Heubach test and amounts of dust were expressed as g 100 kgseeds −1, g 100,000 seeds−1, and g ha−1. The abrasion potential fell generally within the boundaries of maximum permissible values adopted by different countries. Species, seed treatment company, number of active ingredient (AIs) and combination of AIs had significant effects on the abrasion potential, whereas little or no effect of agitation and conservation was found. However, species were situated differently with respect to each other depending on the unit in which the abrasion potential was expressed. A standard unit that takes into account the species’ seed rate is suggested to give the fairest assessment of dust drift risk and would allow international comparison. PMID:27812241

  19. Sliding and Abrasive Wear Behavior of WC-CoCr Coatings with Different Carbide Sizes

    NASA Astrophysics Data System (ADS)

    Thakur, Lalit; Arora, Navneet

    2013-02-01

    This study examines the sliding and abrasive wear behaviors of high-velocity oxy-fuel (HVOF)-sprayed WC-CoCr coatings with different WC grain sizes. The HVOF coating deposition was assisted by in-flight particle temperature and velocity measurement system. The powder feedstocks and their corresponding coatings were characterized by means of XRD and Field Emission Scanning Electron Microscope analysis. Hardness, porosity, and indentation fracture toughness of these coatings were calculated and compared with each other. Sliding wear resistance of these coatings was calculated using pin-on-disk tribometer (ASTM G99-90). The two-body abrasion was quantified by sliding the samples over silicon carbide (SiC) abrasive paper bonded to a rotating flat disk of auto-polisher. The mechanism of materials' removal in both the sliding and abrasive wears was studied and discussed on microstructural investigations. It was observed that fine grain WC-CoCr cermet coating exhibits higher sliding and abrasive wear resistances as compared with conventional cermet coating.

  20. Hybrid layer thickness and morphology: Influence of cavity preparation with air abrasion.

    PubMed

    Barceleiro, Marcos Oliveira; de Mello, Jose Benedicto; Porto, Celso Luis de Angelis; Dias, Katia Regina Hostilio Cervantes; de Miranda, Mauro Sayao

    2011-01-01

    Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation.

  1. Hybrid layer thickness and morphology: Influence of cavity preparation with air abrasion.

    PubMed

    Barceleiro, Marcos Oliveira; de Mello, Jose Benedicto; Porto, Celso Luis de Angelis; Dias, Katia Regina Hostilio Cervantes; de Miranda, Mauro Sayao

    2011-01-01

    Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation. PMID:22313931

  2. Making the cut

    PubMed Central

    Millard, Chris

    2013-01-01

    ‘Deliberate self-harm’, ‘self-mutilation’ and ‘self-injury’ are just some of the terms used to describe one of the most prominent issues in British mental health policy in recent years. This article demonstrates that contemporary literature on ‘self-harm’ produces this phenomenon (to varying extents) around two key characteristics. First, this behaviour is predominantly performed by those identified as female. Second, this behaviour primarily involves cutting the skin. These constitutive characteristics are traced back to a corpus of literature produced in the 1960s and 1970s in North American psychiatric inpatient institutions; analysis shows how pre-1960 works were substantially different. Finally, these gendered and behavioural assertions are shown to be the result of historically specific processes of exclusion and emphasis. PMID:23741086

  3. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-01-31

    Final design of the mast was completed (Task 5). The mast is consisting of two welded plate girders, set next to each other, and spaced 14-inches apart. Fabrication of the boom will be completed in two parts solely for ease of transportation. The end pivot connection will be made through a single 2-inch diameter x 4 feet-8 inch long 316 SS bar. During installation, hard piping make-ups using Chiksan joints will connect the annular section and 4-inch return line to allow full movement of the mast from horizontal to vertical. Additionally, flexible hoses and piping will be installed to isolate both towers from piping loads and allow recycling operations respectively. Calibration of the prototype Foam Generator Cell has been completed and experiments are now being conducted. We were able to generate up to 95% quality foam. Work is currently underway to attach the Thermo-Haake RS300 viscometer and install a view port with a microscope to measure foam bubble size and bubble size distribution. Foam rheology tests (Task 13) were carried out to evaluate the rheological properties of the proposed foam formulation. After successful completion of the first foam test, two sets of rheological tests were conducted at different foam flow rates while keeping other parameters constant (100 psig, 70F, 80% quality). The results from these tests are generally in agreement with the previous foam tests done previously during Task 9. However, an unanticipated observation during these tests was that in both cases, the frictional pressure drop in 2 inch pipe was lower than that in the 3 inch and 4 inch pipes. We also conducted the first foam cuttings transport test during this quarter. Experiments on aerated fluids without cuttings have been completed in ACTF (Task 10). Gas and liquid were injected at different flow rates. Two different sets of experiments were carried out, where the only difference was the temperature. Another set of tests was performed, which covered a wide range of

  4. Vortex cutting in superconductors

    NASA Astrophysics Data System (ADS)

    Glatz, A.; Vlasko-Vlasov, V. K.; Kwok, W. K.; Crabtree, G. W.

    2016-08-01

    Vortex cutting and reconnection is an intriguing and still-unsolved problem central to many areas of classical and quantum physics, including hydrodynamics, astrophysics, and superconductivity. Here, we describe a comprehensive investigation of the crossing of magnetic vortices in superconductors using time dependent Ginsburg-Landau modeling. Within a macroscopic volume, we simulate initial magnetization of an anisotropic high temperature superconductor followed by subsequent remagnetization with perpendicular magnetic fields, creating the crossing of the initial and newly generated vortices. The time resolved evolution of vortex lines as they approach each other, contort, locally conjoin, and detach, elucidates the fine details of the vortex-crossing scenario under practical situations with many interacting vortices in the presence of weak pinning. Our simulations also reveal left-handed helical vortex instabilities that accompany the remagnetization process and participate in the vortex crossing events.

  5. Cross-Cutting Relationships

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 25 August 2003

    The several linear cross-cutting grabens and collapse features observed in this THEMIS image illustrate the relative timing of a series of complex geologic processes as more recent events produce features that overlap and intersect older ones. Some impact craters are observed to be cut grabens, suggesting an older impact event compared to impact craters that appear fresh and unmodified.

    Image information: VIS instrument. Latitude 14.1, Longitude 236.3 East (123.7 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. A study of the abrasive resistance of metal alloys with applications in dental prosthetic fixators.

    PubMed

    Gil, F J; Fernández, E; Manero, J M; Planell, J A; Sabrià, J; Cortada, M; Giner, L

    1995-01-01

    Wear is one of the main surface failure mechanisms in materials and it will play a leading role in substitutive dental biomaterials. The aim of the present study is to compare the abrasive wear of different metallic materials used in dental applications. The results show that the abrasive wear of alloys based on precious metals such as Pt, Pd, Au and Ag is higher than for Ti and Ti based alloys. The alloy with the highest wear resistance is the Co-Cr which exhibits as well the highest hardness and Young's modulus. Since the method corresponds to a well-established abrasive wear standard, the behaviour of the different materials can be easily compared.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  8. Abrasion-ablation model for neutron production in heavy ion reactions

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    In heavy ion reactions, neutron production at forward angles is observed to occur with a Gaussian shape that is centered near the beam energy and extends to energies well above that of the beam. This paper presents an abrasion-ablation model for making quantitative predictions of the neutron spectrum. To describe neutrons produced from the abrasion step of the reaction where the projectile and target overlap, the authors use the Glauber model and include effects of final-state interactions. They then use the prefragment mass distribution from abrasion with a statistical evaporation model to estimate the neutron spectrum resulting from ablation. Measurements of neutron production from Ne and Nb beams are compared with calculations, and good agreement is found.

  9. Influence of alumina and titanium dioxide coatings on abrasive wear resistance of AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Santos, A.; Remolina, A.; Marulanda, J.

    2016-02-01

    This project aims to compare the behaviour of an AISI 1045 steel's abrasive wear resistance when is covered with aluminium oxide (Al2O3) or Titanium dioxide (TiO2), of nanometric size, using the technique of thermal hot spray, which allows to directly project the suspension particles on the used substrate. The tests are performed based on the ASTM G65-04 standard (Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Apparatus). The results show that the amount of, lost material increases linearly with the travelled distance; also determined that the thermal treatment of hardening-tempering and the alumina and titanium dioxide coatings decrease in average a 12.9, 39.6 and 29.3% respectively the volume of released material during abrasive wear test.

  10. Abrasive wear: The efects of fibres size on oil palm empty fruit bunch polyester composite

    NASA Astrophysics Data System (ADS)

    Kasolang, S.; Kalam, A.; Ahmad, M. A.; Rahman, N. A.; Suhadah, W. N.

    2012-06-01

    This paper presents an experimental investigation carried out to determine the effect of palm oil empty fruit bunch (OPEFB) fibre size in dry sliding testing of polyester composite. These composite samples were produced by mixing raw OPEFB fibre with resin. The samples were prepared at different sizes of fibre (100, 125, 180 and 250μm). Abrasion Resistance Tester (TR-600) was used to carried out abrasive wear tests in dry sliding conditions. These tests were performed at room temperature for two different loads (10 and 30N) and at a constant sliding velocity of 1.4m/s. The specific wear rates of OPEFB polyester composites were obtained. The morphology of composite surface before and after tests was also examined using 3D microscope imaging. Preliminary work on thermal distribution at the abrasive wheel point was also conducted for selected samples.

  11. CFD Based Erosion Modelling of Abrasive Waterjet Nozzle using Discrete Phase Method

    NASA Astrophysics Data System (ADS)

    Hakim Kamarudin, Naqib; Prasada Rao, A. K.; Azhari, Azmir

    2016-02-01

    In Abrasive Waterjet (AWJ) machining, the nozzle is the most critical component that influences the performance, precision and economy. Exposure to a high speed jet and abrasives makes it susceptible to wear erosion which requires for frequent replacement. The present works attempts to simulate the erosion of the nozzle wall using computational fluid dynamics. The erosion rate of the nozzle was simulated under different operating conditions. The simulation was carried out in several steps which is flow modelling, particle tracking and erosion rate calculation. Discrete Phase Method (DPM) and K-ε turbulence model was used for the simulation. Result shows that different operating conditions affect the erosion rate as well as the flow interaction of water, air and abrasives. The simulation results correlates well with past work.

  12. Photodetector Development for the Wheel Abrasion Experiment on the Sojourner Microrover of the Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Wilt, David M.; Jenkins, Phillip P.; Scheiman, David A.

    1997-01-01

    On-board the Mars Pathfinder spacecraft, launched in December of 1996, is a small roving vehicle named Sojourner. On Sojourner is an experiment to determine the abrasive characteristics of the Martian surface, called the Wheel Abrasion Experiment (WAE). The experiment works as follows: one of the wheels of the rover has a strip of black anodized aluminum bonded to the tread. The aluminum strip has thin coatings of aluminum, nickel and platinum deposited in patches. There are five (5) patches or samples of each metal, and the patches range in thickness from 200 A to 1000 A. The different metals were chosen for their differing hardness and their environmental stability. As the wheel is spun in the Martian soil, the thin patches of metal are abraded away, exposing the black anodization. The abrasion is monitored by measuring the amount of light reflected off of the samples. A photodetector was developed for this purpose, and that is the subject of this paper.

  13. Friction Process in the Presence of Hard Abrasive Particles — Cooperation Model

    NASA Astrophysics Data System (ADS)

    Oleksowicz, Selim; Mruk, Andrzej

    The paper presents the results of the investigation performed on a stand for model testing of the friction pair like a car disc brake. The tests were performed for the mating operation of a frictional node with the dosage of hard abrasive particles into the friction zone. Based on the observation of the phenomena in the friction zone and the analysis of the parameters describing operating conditions of a frictional node, physical models of the frictional node cooperation in the presence of hard abrasive particles have been proposed. During the tests, using the transparent material of a friction cover plate and a fast recording camera, a visual analysis of the material transfer in the friction zone was done. It allowed to positively verifying the proposed physical models of the frictional node cooperation in the presence of hard abrasive particles.

  14. Understanding Characteristic of Abrasion of Refractory Lining Caused by Bath Oscillation in BOF Steelmaking

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Li, Mingming; Kuang, S. B.; Zou, Zongshu

    2016-08-01

    This paper presents a numerical study of the refractory abrasion occurring widely inside basic oxygen furnace (BOF) steelmaking. The mechanism of refractory abrasion is examined numerically referring to the bath oscillation with regard to flows, turbulence and wall shear stress inside a BOF. The simulation results reveal that the refractory abrasion tends to occur on the wall region between the slag/atmosphere and slag/metal interfaces due to the oscillation of the bath in the blowing process, which generally promotes slag-line erosion. The decreased nozzle angle, and either increased lance height or operation pressure can lead to more serious refractory erosion that occurs more likely during the slag-making period in the operation of BOF.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  16. Considerations on the European Standard EN 14157 Test Methods: Abrasion Resistance of Natural Stones Used for Flooring in Buildings

    NASA Astrophysics Data System (ADS)

    Karaca, Z.; Günes Yılmaz, N.; Goktan, R. M.

    2012-01-01

    In Europe, the Wide Wheel abrasion (WWA) test and the Böhme abrasion (BA) test are among the most widely used standard test methods for determining abrasion resistance of natural stones, the former being the reference test method in EN 14157 Standard. However, it is stated in the Annex-A (Informative) of EN 14157 Standard that very limited data are available to provide correlations between these two test methods. To be able to fill this gap, in this study, 25 different natural stones belonging to sedimentary, metamorphic and igneous groups were tested for their abrasion resistance as well as physico-mechanical properties. Also, for a better interpretation of abrasion resistance characteristics of the tested stone materials, relationships between abrasion resistance and physico-mechanical properties were statistically examined. A statistically significant linear correlation ( R 2 = 0.85; P value = 0.000) was established between the WWA test and the BA test, which could be used in practice for converting the measured abrasion resistance values from one testing method to another. It was also found that the correlation between these two test methods improved significantly ( R 2 = 0.93; P value = 0.001) when relatively high-porosity stone materials (porosity ≥1%) were separately evaluated. Both methods of abrasion resistance employed in the present study showed statistically significant linear correlations with uniaxial compressive strength and Brazilian tensile strength, the former proving to be a more influencing parameter on resistance to abrasion. Also, from the point view of representing actual abrasion mechanism of stone materials in practice, the necessity of simulating multi-directional foot traffic in abrasion testing methods was discussed. In this respect, the reference test method in the EN 14157 Standard was criticized for not fully meeting this requirement. It was also pointed out that the reference method could have some drawbacks when applied to coarse

  17. Comparison of methods for quantifying dental wear caused by erosion and abrasion.

    PubMed

    Passos, Vanara F; Melo, Mary A S; Vasconcellos, Andréa Araújo; Rodrigues, Lidiany K A; Santiago, Sérgio L

    2013-02-01

    Various methods have been applied to evaluate the effect of erosion and abrasion. So, the aim of this study was to check the applicability of stylus profilometry (SP), surface hardness (SH) and focus-variation 3D microscopy (FVM) to the analysis of human enamel and dentin subjected to erosion/abrasion. The samples were randomly allocated into four groups (n = 10): G1-enamel/erosion, G2-enamel/erosion plus abrasion, G3-dentin/erosion, and G4-dentin/erosion plus abrasion. The specimens were selected by their surface hardness, and they were subjected to cycles of demineralization (Coca-Cola®-60 s) and remineralization (artificial saliva-60 min). For groups G2 and G4, the remineralization procedures were followed by toothbrushing (150 strokes). The above cycle was repeated 3×/day during 5 days. The samples were assessed using SH, SP, and FVM. For each substrate, the groups were compared using an unpaired t-test, and Pearson correlation coefficients were calculated (α = 5%). For enamel, both profilometry technique showed greater surface loss when the erosion and abrasion processes were combined (P <0.05). The correlation analysis did not reveal any relationships among SH, SP, and FVM to G2 and G4. There were significant correlation coefficients (-0.70 and -0.67) for the comparisons between the FVM and SH methods in enamel and dentin, respectively, in G1 and G3. Choosing the ideal technique for the analysis of erosion depends on the type of dental substrate. SP was not sufficiently sensitive to measure the effects on dentin of erosion or erosion/abrasion. However, SP, FVM and SH were adequate for the detection of tissue loss and demineralization in enamel. PMID:23129538

  18. Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kathryn C.

    2010-01-01

    During the Apollo program, the space suit outer layer fabrics were badly abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub -layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This Paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, and shares the results and conclusions of the testing.

  19. Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kathryn

    2009-01-01

    During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.

  20. Subsurface mechanical damage during bound abrasive grinding of fused silica glass

    NASA Astrophysics Data System (ADS)

    Blaineau, P.; André, D.; Laheurte, R.; Darnis, P.; Darbois, N.; Cahuc, O.; Neauport, J.

    2015-10-01

    The subsurface damage (SSD) introduced during bound abrasive grinding of fused silica glass was measured using a wet etch technique. Various process parameters and grinding configurations were studied. The relation between the SSD depth, the process parameters and forces applied by the grinding wheel on the sample was investigated and compared to a simulation using a discrete element method to model the grinding interface. The results reveal a relation between the SSD depth and the grinding forces normalized by the abrasive concentration. Regarding the creation of the SSD, numerical simulations indicate that only a small fraction of the largest particles in the diamond wheel are responsible for the depth of the damaged layer.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    SciTech Connect

    Blau, Peter Julian; Dehoff, Ryan R

    2012-01-01

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

  3. Impact of Abrasion on Mass Loss and Surface Appearance of Woven Fabrics Made with Injected Slub Yarn in Weft

    NASA Astrophysics Data System (ADS)

    Ray, Nemai Chandra; Mukhopadhyay, Arunangshu; Midha, Vinay Kumar

    2016-08-01

    Fancy yarn fabrics are susceptible to abrasive damage during washing and usage but the extent of damage varies with construction and type of fabric. In the present study, effect of different slub parameters viz. slub length, slub thickness and slub frequency of single base injected slub yarn on abrasive damage of woven fabrics has been studied when injected slub yarns are used in weft only. Abrasive damage has been assessed by two ways using loss in fabric mass and deterioration in fabric appearance due to abrasion. These two techniques provide entirely different effect of injected slub yarn parameters on abrasive damage of woven fabric. Fabric abrasion damage in terms of mass loss is not affected by slub thickness and damage is least when both slub length and slub frequency are at central/medium level. Under visual assessment it is observed that all the slub parameters have significant influence on abrasive damage of woven fabric. It is possible to have lower damage in surface appearance in spite of higher mass loss of fabric due to abrasion.

  4. Computer Simulation of Stress-Strain State of Pipeline Section Affected by Abrasion Due to Mechanical Impurities

    NASA Astrophysics Data System (ADS)

    Burkov, P. V.; Afanas’ev, R. G.; Burkova, S. P.

    2016-04-01

    The paper presents the effect of abrasive wear of the pipeline section occurred due to mechanical impurities in the transported gas flow. The approaches to the detection of the maximum specific wear of the pipeline wall and the geometry of abrasion are the main problems of computer simulation described in this paper.

  5. Corner-cutting mining assembly

    DOEpatents

    Bradley, John A.

    1983-01-01

    A mining assembly includes a primary rotary cutter mounted on one end of a support shaft and four secondary rotary cutters carried on the same support shaft and positioned behind the primary cutters for cutting corners in the hole cut by the latter.

  6. Cutting and Self-Harm

    MedlinePlus

    ... sad Cutting and self-harm Cutting and self-harm Self-harm, sometimes called self-injury, is when a person ... about how one girl helps herself not self-harm. What are signs of self-injury in others? ...

  7. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, Earl D. (Inventor); Goodfriend, Roger (Inventor)

    1989-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup-shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduces breakage thereof.

  8. Tubing and cable cutting tool

    NASA Technical Reports Server (NTRS)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)

    1984-01-01

    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  9. Conditioning method development for 3M Trizact diamond tile fixed abrasives used in the finishing of brittle substrates; Technical Digest

    NASA Astrophysics Data System (ADS)

    Fletcher, Tim; Gobena, Feben T.; Romero, Vince; Sventek, Bruce; Schoenhofen, Walter

    2005-05-01

    Results of a series of single sided lapping experiments designed to develop appropriate conditioning methods for 3M Trizact Diamond Tile fixed abrasives are reported. Trizact™ Diamond Tile is a structured fixed abrasive lapping technology developed by 3M. The Trizact™ Diamond Tile structured abrasive pad consists of an organic (polymeric binder)-inorganic (abrasive mineral, i.e., diamond) composite that is used with a water-based coolant. The effect of platen and conditioner speed on pad wear will be explored for a roller yoke single-side lapping machine. Pad break-in conditioning was studied in detail for a 6 micron Trizact™ Diamond Tile abrasive used to lap soda-lime glass.

  10. Microstructural influence on abrasive wear resistance of high-strength, high-toughness medium-carbon steels

    SciTech Connect

    Kwok, C.K.; Thomas, G.

    1982-09-01

    A systematic study of abrasive wear resistance of Fe/Cr/Mn experimental steels has been carried out in two-body pin-on-disc abrasion tests. Silicon carbide, alumina, and quartz were used as abrasives. The relationships between microstructures, mechanical properties, and abrasive wear resistance for these experimental steels were studied. In addition, several commercial alloys were tested to provide a basis for comparison. Results show that dislocated lath martensite with continuous interlath film of retained austenite appears to be a desirable microstructure for good wear resistance. Grain refinement by double heat treatment was found to improve the toughness in the experimental steels but have little effect on the abrasive wear resistance. In general, superior tensile properties and wear resistance, without sacrifice in toughness, can be achieved by a lath martensitic microstructure. 8 figures.

  11. Wear Assessment of Conical Pick used in Coal Cutting Operation

    NASA Astrophysics Data System (ADS)

    Dewangan, Saurabh; Chattopadhyaya, Somnath; Hloch, Sergej

    2015-09-01

    Conical pick is a widely used tool for cutting coal in mines. It has a cemented carbide tip inserted in a steel body. Cemented carbide has been in use for many years for coal/rock cutting because it has the optimum combination of hardness, toughness and resistance against abrasive wear. As coal/rock is a heterogeneous substance, the cutting tool has to undergo various obstructions at the time of excavation that cause the tool to wear out. The cracks and fractures developing in the cemented carbide limit the life of the tool. For a long time, different wear mechanisms have been studied to develop improved grades of cemented carbide with high wear resistance properties. The research is still continuing. Moreover, due to the highly unpredictable nature of coal/rock, it is not easy to understand the wear mechanisms. In the present work, an attempt has been made to understand the wear mechanisms in four conical picks, which were used in a continuous miner machine for underground mining of coal. The wearing pattern of the conical pick indicates damage in its cemented carbide tip as well as the steel body. The worn out parts of the tools have been critically examined using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) point analysis. Mainly four types of wear mechanisms, namely, coal/rock intermixing, plastic deformation, rock channel formation and crushing and cracking, have been detected. The presence of coal/rock material and their respective concentrations in the selected area of worn out surface were observed using the spectra generated by EDX analysis.

  12. Analysis of rock deformation and fracture induced by rock-cutting tools used in coal mining. Final report

    SciTech Connect

    Friedman, M.

    1982-10-15

    Deformation induced in Carthage Limestone and Tennessee Sandstone by an Austin AP24 Flat Cutter in laboratory tests consists of four sets of extension fractures and gouge (fine-grained wear particles). The fracture array, inferred sequence of fracture development, and inferred stress field are independent of rock type and texture. The deformation is three-dimensional, extends laterally as much as 1.8 times the half-width of the tool on either side of the tool, and in depth, most of it is confined to the zone 0.07 in. (1.8 mm) below the base of the cutter. As the tool passes a given point the four sets of extension fractures are formed and subsequently the gouge is developed and reworked by shearing. The efficiency of the Austin cutter could be improved by kerfing and by employing water jets that would remove chips bounded by the fractures before energy was wasted grinding and regrinding the chips, fragments and the sides of the groove. Horizontal and vertical cutting forces decrease with increasing depth of cut and when divided by the area of material removed, they tentatively suggest an optimum depth of cut, namely 0.075 in. (1.9 mm). This interesting result needs to be tested much more extensively.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Maintenance and preservation of concrete structures. Report 3: Abrasion-erosion resistance of concrete

    NASA Astrophysics Data System (ADS)

    Liu, T. C.

    1980-07-01

    This report describes a laboratory test program on abrasion-erosion resistance of concrete, including the development of a new underwater abrasion-erosion test method. This program was designed to evaluate the relative abrasion-erosion resistance of various materials considered for use in the repair of erosion-damaged concrete structures. The test program encompassed three concrete types (conventional concrete, fiber-reinforced concrete, and polymer concrete); seven aggregate types (limestone, chert, trap rock, quartzite, granite, siliceous gravel, and slag); three principal water-cement rations (0.72, 0.54, and 0.40); and six types of surface treatment (vacuum, polyurethane coating, acrylic mortar coating, epoxy mortar coating, furan resin mortar coating, and iron aggregate topping). A total of 114 specimens made from 41 batches of concrete was tested. Based on the test data obtained, a comprehensive evaluation of the effects of various parameters on the abrasion-erosion resistance of concrete was presented. Materials suitable for use in the repair of erosion-damaged concrete structures were recommended. Additional work to correlate the reported findings with field performance was formulated.

  16. Abrasion and fracture testing in a high-pressure hydrogen environment

    NASA Technical Reports Server (NTRS)

    Sneesby, G. V.; Walker, R. J.

    1969-01-01

    Two devices are necessary for abrasion and fracture testing of materials evaluated for storage of hydrogen at high pressure for long periods. The first device abrades tensile specimens. The second device tests for fracture toughness of metals. Both devices permit testing in both yield and failure modes in high pressure hydrogen.

  17. Investigation of abrasion in Al–MgO metal matrix composites

    SciTech Connect

    Muharr em Pul; Çalin, Recep; Gül, Ferhat

    2014-12-15

    In this study, the effects of reinforcement volume fractions on abrasive wear behavior were examined in Al–MgO reinforced metal matrix composites of 5%, 10% and 15% reinforcement – volume ratios produced by melt-stirring. Abrasive wear tests were carried out by 60, 80 and 100 mesh sized Al{sub 2}O{sub 3} abrasive papers and pin-on-disc wear test apparatus under 10, 20 and 30 N loads at 0.2 m/s sliding speed. The mechanical properties such as hardness and fracture strength were determined. Subsequent to the wear tests, the microstructures of worn surfaces were examined by scanning electron microscope analyses. While increased MgO reinforcement volume fraction in the composite resulted increased hardness, fracture strength was determined to decrease. Additionally, it was found that increased MgO reinforcement volume fraction in the composite was accompanied with increased wear loss and porosity as well as reinforcement – volume ratio was identified to be significant determinants of abrasive wear behavior.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. 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...

  20. Platelet recruitment promotes keratocyte repopulation following corneal epithelial abrasion in the mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corneal abrasion not only damages the epithelium but also induces stromal keratocyte death at the site of injury. While a coordinated cascade of inflammatory cell recruitment facilitates epithelial restoration, it is unclear if this cascade is necessary for keratocyte recovery. Since platelet and ne...

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

    ERIC Educational Resources Information Center

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

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

  2. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  3. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  4. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  5. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  7. Tribological properties of amorphous alloys and the role of surfaces in abrasive wear of materials

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1982-01-01

    The research approach undertaken by the authors relative to the subject, and examples of results from the authors are reviewed. The studies include programs in adhesion, friction, and various wear mechanisms (adhesive and abrasive wear). The materials which have been studied include such ceramic and metallic materials as silicon carbide, ferrites, diamond, and amorphous alloys.

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

    SciTech Connect

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

    1989-06-01

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

  9. Intraoral leukoplakia, abrasion, periodontal breakdown, and tooth loss in a snuff dipper.

    PubMed

    Christen, A G; Armstrong, W R; McDaniel, R K

    1979-04-01

    Dentists should be aware that snuff dipping or chewing is increasing in southern states and perhaps in other sections of the United States. These habits can lead to clinical leukoplakia, gingival recession, tooth abrasion, and periodontal bone destruction. The possibility also exists that a malignant transformation of leukoplakia can develop in persons who use snuff and other forms of tobacco. PMID:285136

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

    SciTech Connect

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

    2002-06-17

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

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

    SciTech Connect

    Ferguson, R.L.

    1993-10-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP) have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. With the curtailment of reprocessing at the ICPP, the focus of decontamination is shifting from maintenance for continued operation of the facilities to decommissioning. As decommissioning plans are developed, new decontamination methods must be used which result in higher decontamination factors and generate lower amounts of sodium-bearing secondary waste. The primary initiative of the WINCO Decontamination Development Program is the development of methods to eliminate/minimize the use of sodium-bearing decontamination chemicals. One method that was chosen for cold scoping studies during FY-93 was abrasive grit blasting. Abrasive grit blasting has been used in many industries and a vast amount of research and development has already been conducted. However, new grits, process improvements and ICPP applicability was investigated. This evaluation report is a summary of the research efforts and scoping tests using the liquid abrasive grit blasting decontamination technique. The purpose of these scoping tests was to determine the effectiveness of three different abrasive grits: plastic beads, glass beads and alumina oxide.

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

    PubMed Central

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

    2015-01-01

    Background Pleural abrasion has been widely used to control the recurrence of primary spontaneous pneumothorax (PSP). However, controversy still exists regarding the advantages and disadvantages of pleural abrasion compared with other interventions in preventing the recurrence of PSP. Methods The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to December 15, 2014 to identify randomized controlled trials (RCTs) that compared the effects of pleural abrasion with those of other interventions in the treatment of PSP. The study outcomes included the PSP recurrence rate and the occurrence rate of adverse effects. Results Mechanical pleural abrasion and apical pleurectomy after thoracoscopic stapled bullectomy exhibited similarly persistent postoperative air leak occurrence rates (p = 0.978) and 1-year PSP recurrence rates (p = 0.821), whereas pleural abrasion led to reduced residual chest pain and discomfort (p = 0.001) and a smaller rate of hemothorax (p = 0.036) than did apical pleurectomy. However, the addition of minocycline pleurodesis to pleural abrasion did not reduce the pneumothorax recurrence rate compared with apical pleurectomy (3.8% for both procedures) but was associated with fewer complications. There was no statistical difference in the pneumothorax recurrence rate between mechanical pleural abrasion and chemical pleurodesis with minocycline on either an intention-to-treat basis (4 of 42 versus 0 of 42, p = 0.12; Fisher exact test) or after exclusions (2 of 40 versus 0 of 42, p = 0.24; Fisher exact test). Pleural abrasion plus minocycline pleurodesis also did not reduce the pneumothorax recurrence rate compared with pleural abrasion alone (p = 0.055). Moreover, pleural abrasion plus minocycline pleurodesis was associated with more intense acute chest pain. The postoperative overall recurrence rate in patients who underwent staple line coverage with absorbable cellulose mesh and fibrin glue was similar to that

  13. Cutting Force Control Applying Sensorless Cutting Force Monitoring Method

    NASA Astrophysics Data System (ADS)

    Kurihara, Daisuke; Kakinuma, Yasuhiro; Katsura, Seiichiro

    Intelligent machine tools require the functions of high-accurate process monitoring and adaptive control to fit the optimum process condition in each workpieces. For realizing these functions, the various techniques to monitor the cutting process and control it using additional sensors have been proposed and widely studied. Authors propose the sensorless cutting force control method using parallel disturbance observer. The performance of our proposed method is evaluated through simulation and experiments using a linear motor driving table.

  14. Gingival abrasion and recession in manual and oscillating–rotating power brush users

    PubMed Central

    Rosema, NAM; Adam, R; Grender, JM; Van der Sluijs, E; Supranoto, SC; Van der Weijden, GA

    2014-01-01

    Objective To assess gingival recession (GR) in manual and power toothbrush users and evaluate the relationship between GR and gingival abrasion scores (GA). Methods This was an observational (cross-sectional), single-centre, examiner-blind study involving a single-brushing exercise, with 181 young adult participants: 90 manual brush users and 91 oscillating–rotating power brush users. Participants were assessed for GR and GA as primary response variables. Secondary response variables were the level of gingival inflammation, plaque score reduction and brushing duration. Pearson correlation was used to describe the relationship between number of recession sites and number of abrasions. Prebrushing (baseline) and post-brushing GA and plaque scores were assessed and differences analysed using paired tests. Two-sample t-test was used to analyse group differences; ancova was used for analyses of post-brushing changes with baseline as covariate. Results Overall, 97.8% of the study population had at least one site of ≥1 mm of gingival recession. For the manual group, this percentage was 98.9%, and for the power group, this percentage was 96.7% (P = 0.621). Post-brushing, the power group showed a significantly smaller GA increase than the manual group (P = 0.004); however, there was no significant correlation between number of recession sites and number of abrasions for either group (P ≥ 0.327). Conclusions Little gingival recession was observed in either toothbrush user group; the observed GR levels were comparable. Lower post-brushing gingival abrasion levels were seen in the power group. There was no correlation between gingival abrasion as a result of brushing and the observed gingival recession following use of either toothbrush. PMID:24871587

  15. Laser cutting of energetic materials

    SciTech Connect

    Rivera, T.; Muenchausen, R.; Sanchez, J.

    1998-12-01

    The authors have demonstrated the feasibility of safely and efficiently cutting and drilling metal cases containing a variety of high explosives (HE) using a Nd:YAG laser. Spectral analysis of the optical emission, occurring during the laser-induced ablation process, is used to identify the removed material. By monitoring changes in the optical emission during the cutting process, the metal-He interface can be observed in real time and the cutting parameters adjusted accordingly. For cutting the HE material itself, the authors have demonstrated that this can be safely and efficiently accomplished by means of a ultraviolet (UV) laser beam obtained from the same Nd:YAG laser using the third or fourth harmonics. They are currently applying this technology to UXO identification and ordnance demilitarization.

  16. Cutting thin sections of bone

    NASA Technical Reports Server (NTRS)

    Ashley, W. W.

    1972-01-01

    Medical equipment for obtaining repetitive planoparallel sections of bone to study healing of bone structure under high gravity stress is described. Device consists of modified saw with diamond cutting edges. Construction of device and manner of use are explained.

  17. Refrigerated cutting tools improve machining of superalloys

    NASA Technical Reports Server (NTRS)

    Dudley, G. M.

    1971-01-01

    Freon-12 applied to tool cutting edge evaporates quickly, leaves no residue, and permits higher cutting rate than with conventional coolants. This technique increases cutting rate on Rene-41 threefold and improves finish of machined surface.

  18. WC-Co and Cr3C2-NiCr Coatings in Low- and High-Stress Abrasive Conditions

    NASA Astrophysics Data System (ADS)

    Kašparová, Michaela; Zahálka, František; Houdková, Šárka

    2011-03-01

    The article deals with the evaluation of abrasive wear resistance and adhesive strength of thermally sprayed coatings. The main attention was paid to differences between low- and high-stress abrasive conditions of the measuring. Conclusions include the evaluation of specific properties of the WC-Co and the Cr3C2-NiCr High Velocity Oxygen Fuel coatings and the evaluation of the changes in the behavior of the abrasive media. Mainly, the relationship between the low- and high-stress abrasion conditions and the wear mechanism in the tested materials was described. For the wear test, the abrasive media of Al2O3 and SiO2 sands were chosen. During wear tests, the volume loss of the tested materials and the surface roughness of the wear tracks were measured. The wear tracks on the tested materials and abrasive sands' morphologies were observed using Scanning Electron Microscopy. It was found that high-stress abrasive conditions change the coatings' behavior very significantly, particularly that of the Cr3C2-NiCr coating. Adhesive-cohesive properties of the coatings and relationships among individual structure particles were evaluated using tensile testing. It was found that the weak bond strength among the individual splats, structure particles, and phases plays a role in the poor wear resistance of the coatings.

  19. Interactive cutting path analysis programs

    NASA Technical Reports Server (NTRS)

    Weiner, J. M.; Williams, D. S.; Colley, S. R.

    1975-01-01

    The operation of numerically controlled machine tools is interactively simulated. Four programs were developed to graphically display the cutting paths for a Monarch lathe, Cintimatic mill, Strippit sheet metal punch, and the wiring path for a Standard wire wrap machine. These programs are run on a IMLAC PDS-ID graphic display system under the DOS-3 disk operating system. The cutting path analysis programs accept input via both paper tape and disk file.

  20. Microwave assisted hard rock cutting

    DOEpatents

    Lindroth, David P.; Morrell, Roger J.; Blair, James R.

    1991-01-01

    An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

  1. Cutting head for ultrasonic lithotripsy

    NASA Technical Reports Server (NTRS)

    Anguluo, E. D.; Goodfriend, R. (Inventor)

    1985-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument is described. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduce breakage thereof.

  2. EPA rule could cut pollutants

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The U.S. Environmental Protection Agency issued a rule on November 14 that it claims could nearly eliminate dioxin discharges into waterways and reduce other toxic pollutants into the air and water from 155 pulp and paper mills.EPA estimates that results will include a 96% reduction in dioxin and a nearly 60% reduction in toxic air pollutants. Also, volatile organic compounds and sulfur emissions could be cut in half, with particulate matter cut by 37%.

  3. Underwater welding, cutting and inspection

    SciTech Connect

    Tsai, C.L. . Ohio Underwater Welding Center)

    1995-02-01

    Underwater welding, cutting and inspection of offshore, inland waterway and port facilities are becoming a requirement for both military and industrial communities, as maintenance and repair costs continue to escalate, and as many of the facilities are in operation well beyond their intended design life. In nuclear applications, underwater welding, cutting and inspection for repair and modification of irradiated nuclear power plant components are also a requirement. This article summarizes recent developments in this emerging underwater technology.

  4. Economic technology of laser cutting

    NASA Astrophysics Data System (ADS)

    Fedin, Alexander V.; Shilov, Igor V.; Vassiliev, Vladimir V.; Malov, Dmitri V.; Peskov, Vladimir N.

    2000-02-01

    The laser cutting of color metals and alloys by a thickness more than 2 mm has significant difficulties due to high reflective ability and large thermal conduction. We made it possible to raise energy efficiency and quality of laser cutting by using a laser processing system (LPS) consisting both of the YAG:Nd laser with passive Q-switching on base of LiF:F2- crystals and the CO2 laser. A distinctive feature of the LPS is that the radiation of different lasers incorporated in a coaxial beam has simultaneously high level of peak power (more than 400 kW in a TEM00 mode) and significant level of average power (up to 800 W in a TEM01 mode of the CO2 laser). The application of combined radiation for cutting of an aluminum alloy of D16 type made it possible to decrease the cutting energy threshold in 1.7 times, to increase depth of treatment from 2 up to 4 mm, and velocity from 0.015 up to 0.7 m/min, and also to eliminate application of absorptive coatings. At cutting of steels the velocity of treatment was doubled, and also an oxygen flow was eliminated from the technological process and replaced by the air. The obtained raise of energy efficiency and quality of cutting is explained by an essential size reducing of a formed penetration channel and by the shifting of a thermal cutting mode from melting to evaporation. The evaluation of interaction efficiency of a combined radiation was produced on the basis of non-stationary thermal-hydrodynamic model of a heating source moving as in the cutting direction, and also into the depth of material.

  5. Apparatus for washing drill cuttings

    SciTech Connect

    Lott, W. G.

    1985-10-15

    An apparatus for cleansing a stream of drilling fluid fouled drill cuttings having a housing divided into a plurality of compartments each designed to retain cleansing fluid. A spinning force is imparted into the incoming fouled drill cuttings in an inlet chamber wherein cleansing fluid is intimately mixed with the fouled drill cuttings. A decanting chamber removes liberated drilling fluid from the cuttings and disposes of such drilling fluid from the apparatus via a drain trough assembly. The underflow from the decanter is passed through a solids concentrating assembly wherein the coarse solids are deposited in a concentrating assembly bottoms chamber wherein the settled drill cuttings are removed from the apparatus. The overhead stream from the solids concentrating assembly is driected to a second decanter for removal of any remaining drilling fluid and fine drill cuttings entrained therein from the apparatus via the drain trough assembly. The remaining fluid in the concentrating assembly bottoms chamber is recirculated to the second decanting chamber and the inlet chamber.

  6. Comparison between PEEK and Ti6Al4V concerning micro-scale abrasion wear on dental applications.

    PubMed

    Sampaio, M; Buciumeanu, M; Henriques, B; Silva, F S; Souza, J C M; Gomes, J R

    2016-07-01

    In the oral cavity, abrasive wear is predictable at exposed tooth or restorative surfaces, during mastication and tooth brushing. Also, wear can occur at contacting surfaces between the Ti-based prosthetic structures and implants in presence of abrasive compounds from food or toothpaste. Thus, the aim of this work was to compare the abrasive wear resistance of PEEK and Ti6Al4V on three-body abrasion related to different hydrated silica content and loads. Surfaces of Ti6Al4V or PEEK cylinders (8mm diameter and 4mm height) were wet ground on SiC papers and then polished with 1µm diamond paste. After that, surfaces were ultrasonically cleaned in propyl alcohol for 15min and then in distilled water for 10min. Micro-scale abrasion tests were performed at 60rpm and on different normal loads (0.4, 0.8 or 1.2N) after 600 ball revolutions using suspensions with different weight contents of hydrated silica. After abrasive tests, wear scars on flat samples were measured to quantify the wear volume and characterized by scanning electron microscope (SEM) to identify the dominant wear mechanisms. Results showed a higher volume loss rate on PEEK than that recorded on Ti6Al4V,, when subjected to three-body abrasion tests involving hydrated silica suspensions. An increase in volume loss was noted on both tested materials when the abrasive content or load was increased. PEEK was characterized by less wear resistance than that on Ti6Al4V after micro-scale abrasion wear in contact with hydrated silica particles, as commonly found in toothpastes. PMID:26849309

  7. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    Abrasion of mechanical components and fabrics by soil on Earth is typically minimized by the effects of atmosphere and water. Potentially abrasive particles lose sharp and pointed geometrical features through erosion. In environments where such erosion does not exist, such as the vacuum of the Moon, particles retain sharp geometries associated with fracturing of their parent particles by micrometeorite impacts. The relationship between hardness of the abrasive and that of the material being abraded is well understood, such that the abrasive ability of a material can be estimated as a function of the ratio of the hardness of the two interacting materials. Knowing the abrasive nature of an environment (abrasive)/construction material is crucial to designing durable equipment for use in such surroundings. The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed Zone of Interaction (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width. The ZOI has been found to be at least twice the size of a standard width measurement; in some cases, considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for de tailed analysis. Documenting additional changes to various surface roughness par ameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Further - more, by investigating the use of custom scratch tips for specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized

  8. Early abrasion of outer silicone insulation after intracardiac lead friction in a patient with cardiac device-related infective endocarditis.

    PubMed

    Ząbek, Andrej; Małecka, Barbara; Kołodzińska, Agnieszka; Maziarz, Andrej; Lelakowski, Jacek; Kutarski, Andrej

    2012-06-01

    We present a case of a 76-year-old woman on a permanent pacing device, with early abrasion of silicone endocardial lead insulations complicated by lead-dependent infective endocarditis 13 months after placement of an implantable pulse generator. The leads were removed using transvenous technique with direct traction, and with no additional tools. In the previous report, a set of additional tools was used, and therefore intraoperative endocardial lead abrasions or mechanical damage of leads could have not been excluded. The present case undoubtedly proves that the friction of leads against each other may result in abrasions of insulation of the intracardiac section of the lead.

  9. Mitigation of EMU Cut Glove Hazard from Micrometeoroid and Orbital Debris Impacts on ISS Handrails

    NASA Technical Reports Server (NTRS)

    Ryan, Shannon; Christiansen, Eric L.; Davis, Bruce A.; Ordonez, Erick

    2009-01-01

    Recent cut damages sustained on crewmember gloves during extravehicular activity (ISS) onboard the International Space Station (ISS) have been caused by contact with sharp edges or a pinch point according to analysis of the damages. One potential source are protruding sharp edged crater lips from micrometeoroid and orbital debris (MMOD) impacts on metallic handrails along EVA translation paths. A number of hypervelocity impact tests were performed on ISS handrails, and found that mm-sized projectiles were capable of inducing crater lip heights two orders of magnitude above the minimum value for glove abrasion concerns. Two techniques were evaluated for mitigating the cut glove hazard of MMOD impacts on ISS handrails: flexible overwraps which act to limit contact between crewmember gloves and impact sites, and; alternate materials which form less hazardous impact crater profiles. In parallel with redesign efforts to increase the cut resilience of EMU gloves, the modifications to ISS handrails evaluated in this study provide the means to significantly reduce cut glove risk from MMOD impact craters

  10. Relationship between Los Angeles attrition test and Nordic abrasion test of volcanic rocks

    NASA Astrophysics Data System (ADS)

    Krutilová, Kateřina; Prikryl, Richard

    2015-04-01

    Various volcanic rocks contribute significantly to the production of crushed stone in the Czech Republic. When used for road surfacing, results of Los Angeles attrition test (LA value below 25 or 30 depending on the mode of use) together with polished stone value are required. In the recent study, we have focused on the search for possible correlation between results obtained by Los Angeles attrition test and Nordic abrasion test, a test widely employed in Scandinavia. For the experimental study, a set of volcanic rocks from 36 active quarries was used. The rocks under study represent range of volcanic rocks from ultrabasic to acid members, formed form Neoproterozoic to Tertiary. The most favourable results of Los Angeles attrition test (i.e. the lowest LA values) were obtained for basalts (range of values 9.4-19.4) and spilites (range of values 8.4-14.9) which are in fact Neoproterozoic to Late Palaeozoic basalts affected by low grade metamorphism. Nordic abrasion test exhibited much broader range of values (6.4 to 36.9) with average value at 15.2 for basalts, resulting in weak coefficient of determination (0.19). . On contrary, narrow range of values from Nordic abrasion test of spilites (7.2-15.9), very similar to the range of LA values, is reflect in higher coefficient of determination (0.56). On contrary, the least favourable properties (LA values 12.3-29.2, Nordic abrasion 16.8-43.3) have been observed for a group of basic to intermediate rocks classified in older literature as melaphyres and diabases (ranging from basalts to trachyndesites and/or trachybasalts) of Palaeozoic age. However, in this specific group of volcanic rocks, the highest coefficient of determination (0.89) between both tests has been achieved. For volcanic rocks exhibiting acid composition (rhyolites and quartz porphyry), coefficient of determination between LA values (15.1-19.3) and Nordic abrasion test (7.3-21.9) is weak (0.42). The weakest relationship between LA values (14

  11. Abrasion and erosion testing of materials used in power production from coal

    SciTech Connect

    Tylczak, Joseph H.; Adler, Thomas A.; Rawers, James C.

    2003-09-01

    The Albany Research Center (ARC) has a long history of studying abrasive wear, related to mineral testing, handling, and processing. The center has also been instrumental in the design and development of wear test procedures and equipment. Research capabilities at ARC include Pin-on-Drum, Pin-on-Disk, and Dry Sand/Rubber Wheel abrasion tests, Jaw Crusher gouging test, Ball-on-Ball Impact test, and Jet erosion tests. Abrasive and erosive wear studies have been used to develop both new alloys and improved heat treatments of commercial alloys. As part of ARC’s newest iteration on wear testing to evaluate materials for use in new and existing pulverized coal combustion and gasifier power systems, the ARC has designed and constructed a new High Temperature Hostile Atmosphere Erosion Wear Test (HAET). This new piece of test apparatus is designed for erosive particle velocities of 10-40 m/sec and temperatures from room temperature (23°C) to 800+°C, with special control over the gas atmosphere. A variable speed whirling arm design is used to vary the impact energy of the gravity fed erosive particles. The specimens are mounted at the edge of a disk and allow a full range of impingement angles to be selected. An electric furnace heats the specimens in an enclosed retort to the selected temperature. Tests include both oxidizing conditions and reducing conditions. A range of gases, including CO, CO2, CH4, H2, H2S, HCl, N2, O2, and SO2 can be mixed and delivered to the retort. During the erosion testing a stream of abrasive powder is delivered in front of the specimens. This apparatus is designed to use low abrasive fluxes, which simulate real operating conditions in commercial power plants. Currently ~270 μm SiO2 particles are being used to simulate the abrasive impurities typically found in coal. Since operators are always striving for longer lifetimes and higher operating temperatures, this apparatus can help elucidate mechanisms of wastage and identify superior

  12. Micro-abrasion-corrosion behaviour of a biomedical Ti-25Nb-3Mo-3Zr-2Sn alloy in simulated physiological fluid.

    PubMed

    Wang, Zhenguo; Li, Yan; Huang, Weijiu; Chen, Xiaoli; He, Haoran

    2016-10-01

    The micro-abrasion-corrosion behaviour of the biomedical Ti-25Nb-3Mo-3Zr-2Sn alloy in Hank׳s solution with protein has been investigated using electrochemical measurements, tribological tests and scanning electron microscope (SEM) observations. The potentiodynamic polarization tests showed that the corrosion potential (Ecorr) exhibits the maximum value at the abrasive concentration of 0.05gcm(-3) despite of the load level. The tribological results indicated that the total material loss of the Ti-25Nb-3Mo-3Zr-2Sn alloy during micro-abrasion increased with the increasing abrasive concentration at a certain applied load. When the abrasive concentration is no more than 0.15gcm(-3), the total material loss increases with increasing load, while the total material loss exhibits the maximum value at a moderate load in case of higher abrasive concentration levels. This was ascribed to the three-body or two-body micro-abrasion-corrosion at different abrasive concentration levels. The wastage map, abrasion mode map and synergy map associated with the applied load and the abrasive concentration were constructed to evaluate the micro-abrasion-corrosion behaviour of the Ti-25Nb-3Mo-3Zr-2Sn alloy in potential biomedical applications.

  13. Cutting inlays with a laser

    NASA Astrophysics Data System (ADS)

    Swaczyna, Irena; Grabczewski, Zbigniew

    1995-03-01

    To cut inlay from a stack of glued veneer a CO2 HEBAR-1A laser was used. For setting optimal working parameters of the set used in industrial production of inlay the following elements were defined: the shape and dimensions of the cutting fissure, the dependence between the width of the cutting fissure and the speed with which the laser beam moves and the total thickness of the stack of veneer sheets, the application of the laser for cutting various patterns. Computer aided designing and computer steering of the laser beam enables fast and precise production of large numbers of inlay elements not only from wood but also from other materials like glass, stone, metal, etc. Taking into consideration the high running cost of such a laser set and its very big production only few factories or even one factory in the given area could produce inlay ready for gluing. Further investigation should be carried out on this field particularly considering the lowering of costs not only in inlay production but generally where cutting of wood is concerned.

  14. Grinding force and microcrack density in abrasive machining of silicon nitride

    SciTech Connect

    Xu, H.H.K.; Wei, L.; Jahanmir, S.

    1995-12-01

    The relationship between grinding forces and the material`s resistance to microfracture is investigated in abrasive machining of silicon nitride ceramics. Surface grinding is performed on two forms of silicon nitride with different microstructures, and the grinding forces are measured. In addition, single-point scratching is performed on polished surfaces to amplify the damage associated with the action of an individual abrasive particle in grinding. A thermal wave measurement technique in then used on the cross sections to characterize the density of subsurface microcracks associated with scratching. Compared to a fine-grain silicon nitride, the density of microcracks in a coarse-grain silicon nitride is significantly larger, while the grinding force is smaller. The smaller grinding force for the coarse-grain silicon nitride is attributed to the ease of local intergranular microfracture and grain dislodgement during grinding. {copyright} {ital 1995} {ital Materials} {ital Research} {ital Society}.

  15. Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics

    NASA Astrophysics Data System (ADS)

    Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

    2013-10-01

    Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8 kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect.

  16. A Study on 3-Body Abrasive Wear Behaviour of Aluminium 8011 / Graphite Metal Matrix Composite

    NASA Astrophysics Data System (ADS)

    Latha Shankar, B.; Anil, K. C.; Patil, Rahul

    2016-09-01

    Metals and alloys have found their vital role in many applications like structural, corrosive, tribological, etc., in engineering environment. The alloys/composites having high strength to low weight ratio have gained attention of many researchers recently. In this work, graphite reinforced Aluminium 8011 metal matrix composite was prepared by conventional stir casting route, by varying the weight % of reinforcement. Uniform distribution of Graphite in matrix alloy was confirmed by optical micrographs. Prepared composite specimens were subjected to 3-body abrasive testing by varying applied load and time, the silica particles of 400 grit size were used as abrasive particles. It was observed that with the increase of weight% of Graphite the wear resistance of composite was also increasing and on comparison it was found that reinforced composite gives good wear resistance than base alloy.

  17. M"ossbauer study of corrosion and abrasion products in oil transporting pipes

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Perez Mazariego, Jose Luis; Marquina, Vivianne; Marquina, Ma. Luisa; Ridaura, Rosalia; Martinez, Lorenzo

    2012-02-01

    It is known that one of the main technological problems in carbon steel oleoducts is the corrosion produced by different substances, such as water, carbon dioxide, sulfur, and microorganisms. In addition, if in such mixture there is sand, aggressive sludge can be form that abrasions material from the oleoduct. A room temperature M"ossbauer study of corroded material taken from different sites of oleoducts is presented. Most of the M"ossbauer spectra reveal the presence of nanoparticles, indicating that in these pipes the abrasion problem is severe. A preliminary identification of the oxidized samples suggests the presence of magnetite, and some Iron hydroxides. Further studies are in course in order to identify unambiguously the products present in the corroded materials.

  18. Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics

    PubMed Central

    Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

    2013-01-01

    Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8 kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect. PMID:24135813

  19. Erosion and abrasion on dental structures undergoing at-home bleaching

    PubMed Central

    Demarco, Flávio Fernando; Meireles, Sônia Saeger; Sarmento, Hugo Ramalho; Dantas, Raquel Venâncio Fernandes; Botero, Tatiana; Tarquinio, Sandra Beatriz Chaves

    2011-01-01

    This review investigates erosion and abrasion in dental structures undergoing at- home bleaching. Dental erosion is a multifactorial condition that may be idiopathic or caused by a known acid source. Some bleaching agents have a pH lower than the critical level, which can cause changes in the enamel mineral content. Investigations have shown that at-home tooth bleaching with low concentrations of hydrogen or carbamide peroxide have no significant damaging effects on enamel and dentin surface properties. Most studies where erosion was observed were in vitro. Even though the treatment may cause side effects like sensitivity and gingival irritation, these usually disappear at the end of treatment. Considering the literature reviewed, we conclude that tooth bleaching agents based on hydrogen or carbamide peroxide have no clinically significant influence on enamel/dentin mineral loss caused by erosion or abrasion. Furthermore, the treatment is tolerable and safe, and any adverse effects can be easily reversed and controlled. PMID:23674914

  20. The effectiveness of the air-powder abrasive device on the tooth and periodontium: an overview.

    PubMed

    Kozlovsky, A; Soldinger, M; Sperling, I

    1989-01-01

    The characteristics of the air-powder abrasive device (APAD) was reviewed from the current dental literature and found to be an excellent alternative to traditional methods for stain and plaque removal. Access to crowded teeth, grooves and involved furcation areas are easily obtainable with less operator fatigue. The APAD slurry produces different root surface abrasiveness, depending on the method of use. Extended maintenance periods of exposed root surface using the APAD can result in an enormous loss of root structure. To avoid permanent damage of the root, the device should be used with overlapping strokes and root exposure to the APAD slurry should be minimized. The device can be used for total cementum removal with less operator fatigue and more reproducibility than with hand instruments, leaving smooth and clean surfaces. In addition, the device may be a valuable tool in the detoxification of root surfaces during periodontal surgery.

  1. Process for producing a well-adhered durable optical coating on an optical plastic substrate. [abrasion resistant polymethyl methacrylate lenses

    NASA Technical Reports Server (NTRS)

    Kubacki, R. M. (Inventor)

    1978-01-01

    A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.

  2. Abrasive stripping square-wave voltammetry of blackberry, raspberry, strawberry, pomegranate, and sweet and blue potatoes.

    PubMed

    Komorsky-Lovrić, Šebojka; Novak, Ivana

    2011-08-01

    Electro-oxidation potentials of 7 fruits and vegetables were determined by abrasive stripping voltammetry. The responses were characterized by 2 peaks with maxima at 0.45 and 0.55 V compared with Ag/AgCl, respectively. Both electrode reactions appear reversible at a frequency of 8 Hz. They can be ascribed to anthocyanidins and ellagic acid as electroactive compounds. By this method, an antioxidative capacity of a certain plant can be quickly estimated without extraction of active components.

  3. Heat sealable, flame and abrasion resistant coated fabric. [clothing and containers for space exploration

    NASA Technical Reports Server (NTRS)

    Tschirch, R. P.; Sidman, K. R. (Inventor)

    1981-01-01

    Flame retardant, abrasion resistant elastomeric compositions are comprised of thermoplastic polyurethane polymer and flame retarding amounts of a filler selected from decabromodiphenyloxide and antimony oxide in a 3:1 weight ratio, and decabromodiphenyloxide, antimony oxide, and ammonium polyphosphate in a 3:1:3 weight ratio respectively. Coated fabrics employing such elastomeric compositions as coating film are flexible, lightweight, and air impermeable and can be made using heat or dielectric sealing procedures.

  4. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed Zone of Interaction (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width as currently defined by the ASTM G 171 Standard. The ZOI has been found to be at least twice the size of a standard width measurement, in some cases considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for detailed analysis. Documenting additional changes to various surface roughness parameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Data are presented to show that different combinations of scratch tips and abraded materials can actually yield the same scratch width, but result in different volume displacement or removal measurements and therefore, the ZOI method is more discriminating than the ASTM method scratch width. Furthermore, by investigating the use of custom scratch tips for our specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized manner, and not just by scratch width alone, is reinforced. This benefit is made apparent when a tip creates an intricate contour having multiple peaks and valleys within a single scratch. This work lays the foundation for updating scratch measurement standards to improve modeling and characterization of three-body abrasion test results.

  5. Abrasive Wear Performance of Aluminium Modified Epoxy-Glass Fiber Composites

    NASA Astrophysics Data System (ADS)

    Kamble, Vikram G.; Mishra, Punyapriya; Al Dabbas, Hassan A.; Panda, H. S.; Fernandez, Johnathan Bruce

    2015-07-01

    For a long time, Aluminum filled epoxies molds have been used in rapid tooling process. These molds are very economical when applied in manufacturing of low volume of plastic parts. To improve the thermal conductivity of the material, the metallic filler material is added to it and the glass fiber improves the wear resistance of the material. These two important parameters establish the life of composites. The present work reports on abrasive wear behavior of Aluminum modified epoxy and glass fiber composite with 5 wt.% and 10 wt.% of aluminum particles. Through pin on disc wear testing machine, we studied the wear behaviors of composites, and all these samples were fabricated by using hand layup process. Epoxy resin was used as matrix material which was reinforced with Glass fiber and Aluminum as filler. The composite with 5 wt.% and 10 wt.% of Al was cast with dimensions 100 × 100 × 6 mm. The specimens were machined to a size of 6 × 6 × 4 mm for abrasive testing. Abrasive tests were carried out for different grit paper sizes, i.e., 150, 320, 600 at different sliding distance, i.e., 20, 40, 60 m at different loads of 5, 10 and 15 N and at constant speed. The weight loss due to wear was calculated along with coefficient of friction. Hardness was found using Rockwell hardness machine. The SEM morphology of the worn out surface wear was analyzed to understand the wear mechanism. Results showed that the addition of Aluminum particles was beneficial for low abrasive conditions.

  6. Effects of Different Lasers and Particle Abrasion on Surface Characteristics of Zirconia Ceramics

    PubMed Central

    Arami, Sakineh; Tabatabae, Masoume Hasani; Namdar, Seyedeh Fatemeh; Chiniforush, Nasim

    2014-01-01

    Objective: The aim of this study was to assess the surface of yttrium-stabilized tetragonal zirconia (Y-TZP) after surface treatment with lasers and airborne-particle abrasion. Materials and Methods: First, 77 samples of presintered zirconia blocks measuring 10 × 10 × 2 mm were made, sintered and polished. Then, they were randomly divided into 11 groups (n=7) and received surface treatments namely, Er:YAG laser irradiation with output power of 1.5, 2 and 2.5 W, Nd:YAG laser with output power of 1.5, 2 and 2.5 W, CO2 laser with output power of 3, 4 and 5 W, AL2O3 airborne-particle abrasion (50μ) and no treatment (controls). Following treatment, the parameters of surface roughness such as Ra, Rku and Rsk were evaluated using a digital profilometer and surface examination was done by SEM. Results: According to ANOVA and Tukey’s test, the mean surface roughness (Ra) after Nd:YAG laser irradiation at 2 and 2.5 W was significantly higher than other groups. Roughness increased with increasing output power of Nd:YAG and CO2 lasers. Treated surfaces by Er:YAG laser and air abrasion showed similar surface roughness. SEM micrographs showed small microcracks in specimens irradiated with Nd:YAG and CO2 lasers. Conclusion: Nd:YAG laser created a rough surface on the zirconia ceramic with many microcracks; therefore, its use is not recommended. Air abrasion method can be used with Er:YAG laser irradiation for the treatment of zirconia ceramic. PMID:24910700

  7. Inorganic-organic hybrid materials and abrasion resistant coatings based on a sol-gel approach

    SciTech Connect

    Betrabet, C.S.

    1993-01-01

    Attempts to synthesize hybrid materials from polytetramethylene oxide (PTMO) end-functionalized with triethoxy silyl groups and, tetraethylorthosilicate (TEOS) under basic conditions met with only partial success. The films obtained had low mechanical stability. In contrast, films with good mechanical stability were obtained when the TEOS was replaced with tritanium tetraisopropoxide (TIOPR). The microstructure of the TIOPR/PTMO hybrid synthesized under near neutral conditions was generally similar to the acid catalyzed PTMO/TIOPR hybrids. In another closely related study, the effect of subjecting acid catalyzed hybrid materials to aqueous and basic solutions was examined. Two chemically different systems were chosen which were namely the PTMO-TEOS system and the PTMO-TIOPR system. In addition to the difference in the reactivity between the TEOS and TIOPR, another point of differentiation was the relative solubility of the silicon oxide in basic aqueous solutions in contrast to the relative insolubility of the titanium oxide species in all but the very concentrated basic solutions. An application of the hybrid materials in the area of abrasion resistant coatings was also studied. The effects of the various organic structures on abrasion resistance, the extent of reaction and the mechanism of abrasion was examined. Various low molecular weight organics were functionalized triethoxy silyl groups and coated on polycarbonate and cured. They were then subjected to a Taber abrader test. The results showed that all the functionalized organics showed better abrasion resistance than the polycarbonate if sufficiently cured. NMR data showed that the reaction of the functionalized coatings was limited by vitrification and the extent of reaction was influenced by the basicity of the organic backbone. SEM observations of the abraded surfaces showed that the polycarbonate was abraded by a mechanism different from the functionalized coatings.

  8. The Nichols Wing Cutting Equipment

    NASA Technical Reports Server (NTRS)

    Ford, James B

    1923-01-01

    Described here is wing cutting equipment for the economical production of metal wings for wind tunnel models. The machine will make any size of constant-section wing or strut up to one-sixth inch chord by 36-inch span and up to a thickness of one and one-quarter inches. It cuts a smooth, true model that is accurate to within two-thousandths of an inch on any ordinate. The holding jaws are so designed as to leave the model free of chip marks, and the only hand finishing necessary after the cutting is a rub with amunite to remove burrs. The actual change on ordinate in this finishing rub is less than .0002 inches.

  9. Haptic feedback for multilayer cutting.

    PubMed

    Rianto, Sugeng; Li, Ling; Hartley, Bruce

    2008-01-01

    An approach in effectively estimating the force feedback for a tactile haptic based on multi-proxy rendering for 3D surface cuttings for a virtual surgery simulation is described in this paper. The force-models representing haptic force-feedback are approximated using D'Alembert's principle in the mechanic case of spring-damper-stiffness interaction of the surfaces. We also propose a combination between mesh refinement and adaptive re-meshing to create a progressive cutting over the layering surfaces. Experimental results prove that the physical interaction to create cutting paths over the multilayer surfaces can be deliver smoothly with haptic in real time with 3D visual stereo on a PC.

  10. Evaluation of planarization performance for a novel alkaline copper slurry under a low abrasive concentration

    NASA Astrophysics Data System (ADS)

    Mengting, Jiang; Yuling, Liu; Haobo, Yuan; Guodong, Chen; Weijuan, Liu

    2014-11-01

    A novel alkaline copper slurry that possesses a relatively high planarization performance is investigated under a low abrasive concentration. Based on the action mechanism of CMP, the feasibility of using one type of slurry in copper bulk elimination process and residual copper elimination process, with different process parameters, was analyzed. In addition, we investigated the regular change of abrasive concentration effect on copper and tantalum removal rate and within wafer non-uniformity (WIWNU) in CMP process. When the abrasive concentration is 3 wt%, in bulk elimination process, the copper removal rate achieves 6125 Å/min, while WIWNU is 3.5%, simultaneously. In residual copper elimination process, the copper removal rate is approximately 2700 Å/min, while WIWNU is 2.8%. Nevertheless, the tantalum removal rate is 0 Å/min, which indicates that barrier layer isn't eliminated in residual copper elimination process. The planarization experimental results show that an excellent planarization performance is obtained with a relatively high copper removal rate in bulk elimination process. Meanwhile, after residual copper elimination process, the dishing value increased inconspicuously, in a controllable range, and the wafer surface roughness is only 0.326 nm (sq < 1 nm) after polishing. By comparison, the planarization performance and surface quality of alkaline slurry show almost no major differences with two kinds of commercial acid slurries after polishing. All experimental results are conducive to research and improvement of alkaline slurry in the future.

  11. Nuclear-chemical methods in a hard tooth tissue abrasion study

    NASA Astrophysics Data System (ADS)

    Gosman, A.; Spěváček, V.; Koníček, J.; Vopálka, D.; Houŝová, D.; Doležalová, L.

    1999-01-01

    The advanced method consists in implantation—labelling of the thin surface layers of the solid objects, e.g. hard tooth tissue, by atoms of suitable natural or artificial radionuclides. Nuclides from the uranium series were implanted into the surface by using nuclear recoil effect at alpha decay of 226Ra to 222Rn, alpha decay of 222Rn to RaA, alpha decay of RaA to RaB (beta-emitter) and further alpha or beta emitters. With regard to chosen alpha detection and to the half—lives of the radionuclides, there was actually measured the activity of 222Rn, RaA and RaC’ in the thin surface layer. This was followed by the laboratory simulation of the abrasion in the system of “toothbrush—various suspensions of the tooth-pastes—hard tooth tissue (or material standard—ivory)” in specially designed device—the dentoabrasionmeter. The activities of the tissue surface measured before and after abrasion were used for calculations of the relative drop of the surface activity. On this basis the influence of various tooth-pastes containing various abrasive substances was determined.

  12. Effect of consolidation on adhesive and abrasive wear of ultra high molecular weight polyethylene.

    PubMed

    Gul, Rizwan M; McGarry, Frederick J; Bragdon, Charles R; Muratoglu, Orhun K; Harris, William H

    2003-08-01

    Total hip replacement (THR) is widely performed to recover hip joint functions lost by trauma or disease and to relieve pain. The major cause of failure in THR is the wear of the ultra high molecular weight polyethylene (UHMWPE) component. The dominant wear mechanism in THR occurs through adhesion and abrasion. While poor consolidation of UHMWPE is known to increase the incidence of a different damage mode, delamination, which is the dominant wear mechanism in tibial inserts but uncommon in THR, the effect of consolidation on adhesive and abrasive wear of UHMWPE is not clear. In this study UHMWPE resin was subjected to hot isostatic pressing under a pressure of 138MPa at different temperatures (210 degrees C, 250 degrees C, and 300 degrees C) to achieve varying degrees of consolidation. The extent of consolidation was determined by optical microscopy using thin sections, and by scanning electron microscopy using cryofractured and solvent etched specimens. Wear behavior of the samples with varying degree of consolidation was determined using a bi-directional pin-on-disc machine simulating conditions in a hip joint. Increasing the processing temperature decreased the incidence of fusion defects and particle boundaries reflecting the powder flakes of the virgin resin, improving the consolidation. However, the bi-directional pin-on-disc wear rate did not change with the processing temperature, indicating that adhesive and abrasive wear is independent of the extent of consolidation in the range of parameters studied here. PMID:12763446

  13. Microstructure and Abrasive Wear Performance of Ni-Wc Composite Microwave Clad

    NASA Astrophysics Data System (ADS)

    Bansal, Amit; Zafar, Sunny; Sharma, Apurbba Kumar

    2015-10-01

    In the present work, Ni-WC powder was deposited on mild steel substrate to develop clads through microwave hybrid heating technique. The cladding trials were carried out in an industrial microwave applicator at 1.1 kW for 540 s. The Ni-WC composite clads were characterized for microstructure and abrasive wear performance through combination of x-ray diffraction, electron and optical microscopy, microhardness, and wear tests. Phase analysis of the Ni-WC clad indicated the presence of stable carbides such as WC, W2C, Ni2W4C, and Fe6W6C. The microstructure study of the clad layer revealed the presence of a uniformly distributed interlocked WC-based reinforcement embedded in the Ni-based matrix. The average Vicker's microhardness in the clad layer was observed to be 1028 ± 90 HV, which was approximately three times the microhardness of the substrate. Abrasive wear resistance of the microwave clads was superior to the MS substrate. Abrasion was the main wear mechanism in the Ni-WC clads and the substrate samples. However, the presence of WC-based reinforcement in the composite clads reduced microcutting, resulting in enhanced wear resistance.

  14. Property-process relations in simulated clinical abrasive adjusting of dental ceramics.

    PubMed

    Yin, Ling

    2012-12-01

    This paper reports on property-process correlations in simulated clinical abrasive adjusting of a wide range of dental restorative ceramics using a dental handpiece and diamond burs. The seven materials studied included four mica-containing glass ceramics, a feldspathic porcelain, a glass-infiltrated alumina, and a yttria-stabilized tetragonal zirconia. The abrasive adjusting process was conducted under simulated clinical conditions using diamond burs and a clinical dental handpiece. An attempt was made to establish correlations between process characteristics in terms of removal rate, chipping damage, and surface finish and material mechanical properties of hardness, fracture toughness and Young's modulus. The results show that the removal rate is mainly a function of hardness, which decreases nonlinearly with hardness. No correlations were noted between the removal rates and the complex relations of hardness, Young's modulus and fracture toughness. Surface roughness was primarily a linear function of diamond grit size and was relatively independent of materials. Chipping damage in terms of the average chipping width decreased with fracture toughness except for glass-infiltrated alumina. It also had higher linear correlations with critical strain energy release rates (R²=0.66) and brittleness (R²=0.62) and a lower linear correlation with indices of brittleness (R²=0.32). Implications of these results can provide guidance for the microstructural design of dental ceramics, optimize performance, and guide the proper selection of technical parameters in clinical abrasive adjusting conducted by dental practitioners.

  15. Ergonomics of abrasive blasting: a comparison of high pressure water and steel shot.

    PubMed

    Rosenberg, Beth; Yuan, Lu; Fulmer, Scott

    2006-09-01

    Abrasive blasting with silica sand has long been associated with silicosis. Alternatives to sand are being used increasingly. While NIOSH has done extensive investigations of the respiratory effects of the substitutes for sand, the ergonomic effects of the substitutes have not been examined. Too often, hazards are shifted, and technologies that might save workers' lungs could do so at the expense of their musculoskeletal systems. Hence, the objective of this study was to examine the ergonomic effects of alternatives to sand. Multiple methods, both qualitative and quantitative, were used to yield numerous kinds of data for the analysis of exposures to abrasive blasters. PATH, a method for quantifying ergonomic exposure in non-routine work, was combined with interviews with workers, biomechanical modeling and noise level readings to assess the ergonomics of two abrasive blasting operations: high-pressure water and steel shot. Advantages and disadvantages of each medium are discussed. High-pressure water was slightly less ergonomically stressful, environmentally cleaner, much quieter and less dusty that steel shot, and it was reported to be slower on those tasks where both media could be used.

  16. Adhesive interfaces of enamel and dentin prepared by air-abrasion at different distances

    NASA Astrophysics Data System (ADS)

    Chinelatti, Michelle Alexandra; do Amaral, Thais Helena Andreolli; Borsatto, Maria Cristina; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

    2007-03-01

    The purpose of this study was to analyse, by scanning electron microscopy (SEM), the morphology of enamel and dentin/adhesive interfaces in cavities prepared by air-abrasion at different working distances. Thirty sound third human molars were selected and, on both their buccal and lingual surfaces, class V cavities were prepared by air-abrasion, at 2-, 4-, 6-, 8- and 10-mm working distances, or high-speed bur (control group). After preparation, all cavities were etched with 35% phosphoric acid gel and restored with Single Bond/Filtek Z-250. Buccal and lingual surfaces were separated and restorations sectioned in a buccolingual direction, providing two sections of each cavity, which were analysed by scanning electron microscopy. It was observed that the distances of 6 and 8 mm promoted more homogeneous dentin/adhesive interfaces, with tags formation, and more uniform for enamel, which were similar to the control group. It may be concluded that the air-abrasion working distance can influence the morphology of enamel and dentin/adhesive interfaces, and the intermediate distances provided better adhesive interfaces.

  17. Soil abrasion and eolian dust production: Implications for iron partitioning and solubility

    NASA Astrophysics Data System (ADS)

    Mackie, D. S.; Peat, J. M.; McTainsh, G. H.; Boyd, P. W.; Hunter, K. A.

    2006-12-01

    Eolian dust is a source of iron for phytoplankton in many ocean areas, and there are complex pathways of atmospheric processing from soil to ocean. Overlooked parts of the pathways are the impact of large (>10 μm) grains (including a role as proxies for the behavior of smaller grains) and the effect of multiple cycles of uplift and abrasion in the dust source region. Partitioning (readily released, acid-leachable and refractory) and dissolution rates of iron were determined for an artificial dust (produced by abrading an Australian soil), untreated soil, abraded soil (after production of the artificial dust), and a natural Australian eolian dust sample taken during a dust storm. Readily released iron is not created during abrasion, and therefore the amount of readily released iron in a dust or dust-derived soil depends on processing events since the dust or soil last experienced an abrasion event. Our study develops a method for the partitioning of iron within airborne dusts and appears to be the first to consider the effect of multiple uplift events on iron partitioning.

  18. Development and Testing of Abrasion Resistant Hard Coats For Polymer Film Reflectors: Preprint

    SciTech Connect

    Jorgensen, G.; Gee, R.; DiGrazia, M.

    2010-10-01

    Reflective polymer film technology can significantly reduce the cost of solar reflectors and installed Concentrated Solar Power (CSP) plants by both reduced material cost and lower weight. One challenge of polymer reflectors in the CSP environment pertains to contact cleaning methods typically used with glass mirrors. Such contact cleaning methods can scratch the surface of polymer reflectors and thereby reduce specular reflectance. ReflecTech, Inc. (a subsidiary of SkyFuel, Inc.) and the National Renewable Energy Laboratory (NREL) initiated a cooperative research and development agreement (CRADA) to devise and develop an abrasion resistant coating (ARC) suitable for deposition onto polymer based mirror film. A number of candidate ARC products were identified as candidate formulations. Industrial collaborators prepared samples having their ARCs deposited onto ReflecTech Mirror Film pre-laminated to aluminum sheet substrates. Samples were provided for evaluation and subjected to baseline (unweathered) and accelerated exposure conditions and subsequently characterized for abrasion resistance and adhesion. An advanced ARC product has been identified that exhibits outstanding initial abrasion resistance and adhesion to ReflecTech Mirror Film. These properties were also retained after exposure to the various accelerated stress conditions. This material has been successfully manufactured as a 1.5 m wide roll-to-roll construction in a production environment.

  19. Defining an Abrasion Index for Lunar Surface Systems as a Function of Dust Interaction Modes and Variable Concentration Zones

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and subcategorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a single particle or asperity slides across a given surface removing or displacing material. Three-body abrasion occurs when multiple particles interact with a solid surface, or in between two surfaces, allowing the abrasives to freely rotate and interact with the material(s), leading to removal or displacement of mass. Different modes of interaction are described in this paper along with corresponding types of tests that can be utilized to evaluate each configuration. In addition to differential modes of abrasion, variable concentrations of dust in different zones can also be considered for a given system design and operational protocol. These zones include: (1) outside the habitat where extensive dust exposure occurs, (2) in a transitional zone such as an airlock or suitport, and (3) inside the habitat or spacesuit with a low particle count. These zones can be used to help define dust interaction frequencies, and corresponding risks to the systems and/or crew can be addressed by appropriate mitigation strategies. An abrasion index is introduced that includes the level of risk, R, the hardness of the mineralogy, H, the severity of the abrasion mode, S, and the frequency of particle interactions, F.

  20. Stresses in ultrasonically assisted bone cutting

    NASA Astrophysics Data System (ADS)

    Alam, K.; Mitrofanov, A. V.; Bäker, M.; Silberschmidt, V. V.

    2009-08-01

    Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

  1. Hypervelocity cutting machine and method

    DOEpatents

    Powell, James R.; Reich, Morris

    1996-11-12

    A method and machine 14 are provided for cutting a workpiece 12 such as concrete. A gun barrel 16 is provided for repetitively loading projectiles 22 therein and is supplied with a pressurized propellant from a storage tank 28. A thermal storage tank 32,32A is disposed between the propellant storage tank 28 and the gun barrel 16 for repetitively receiving and heating propellant charges which are released in the gun barrel 16 for repetitively firing projectiles 22 therefrom toward the workpiece 12. In a preferred embodiment, hypervelocity of the projectiles 22 is obtained for cutting the concrete workpiece 12 by fracturing thereof.

  2. Hypervelocity cutting machine and method

    DOEpatents

    Powell, J.R.; Reich, M.

    1996-11-12

    A method and machine are provided for cutting a workpiece such as concrete. A gun barrel is provided for repetitively loading projectiles therein and is supplied with a pressurized propellant from a storage tank. A thermal storage tank is disposed between the propellant storage tank and the gun barrel for repetitively receiving and heating propellant charges which are released in the gun barrel for repetitively firing projectiles therefrom toward the workpiece. In a preferred embodiment, hypervelocity of the projectiles is obtained for cutting the concrete workpiece by fracturing thereof. 10 figs.

  3. Microbiopsy/precision cutting devices

    DOEpatents

    Krulevitch, Peter A.; Lee, Abraham P.; Northrup, M. Allen; Benett, William J.

    1999-01-01

    Devices for performing tissue biopsy on a small scale (microbiopsy). By reducing the size of the biopsy tool and removing only a small amount of tissue or other material in a minimally invasive manner, the risks, costs, injury and patient discomfort associated with traditional biopsy procedures can be reduced. By using micromachining and precision machining capabilities, it is possible to fabricate small biopsy/cutting devices from silicon. These devices can be used in one of four ways 1) intravascularly, 2) extravascularly, 3) by vessel puncture, and 4) externally. Additionally, the devices may be used in precision surgical cutting.

  4. Microbiopsy/precision cutting devices

    DOEpatents

    Krulevitch, P.A.; Lee, A.P.; Northrup, M.A.; Benett, W.J.

    1999-07-27

    Devices are disclosed for performing tissue biopsy on a small scale (microbiopsy). By reducing the size of the biopsy tool and removing only a small amount of tissue or other material in a minimally invasive manner, the risks, costs, injury and patient discomfort associated with traditional biopsy procedures can be reduced. By using micromachining and precision machining capabilities, it is possible to fabricate small biopsy/cutting devices from silicon. These devices can be used in one of four ways (1) intravascularly, (2) extravascularly, (3) by vessel puncture, and (4) externally. Additionally, the devices may be used in precision surgical cutting. 6 figs.

  5. Document segmentation via oblique cuts

    NASA Astrophysics Data System (ADS)

    Svendsen, Jeremy; Branzan-Albu, Alexandra

    2013-01-01

    This paper presents a novel solution for the layout segmentation of graphical elements in Business Intelligence documents. We propose a generalization of the recursive X-Y cut algorithm, which allows for cutting along arbitrary oblique directions. An intermediate processing step consisting of line and solid region removal is also necessary due to presence of decorative elements. The output of the proposed segmentation is a hierarchical structure which allows for the identification of primitives in pie and bar charts. The algorithm was tested on a database composed of charts from business documents. Results are very promising.

  6. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    NASA Astrophysics Data System (ADS)

    Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

    2014-06-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  7. Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness.

    PubMed

    Müller, J; Clauss, M; Codron, D; Schulz, E; Hummel, J; Kircher, P; Hatt, J-M

    2015-06-01

    Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species.

  8. Pulpal response to different pulp capping methods after pulp exposure by air abrasion.

    PubMed

    Cardenas-Duque, Lina Maria; Yoshida, Makoto; Goto, George

    2002-01-01

    Air abrasion is regaining popularity especially in the area of pediatric dentistry due to its ease of use and its advantages. Due to the lost of tactile information, while using this technique, there is an increased risk for pulpal exposure. On the other hand, Ca(OH)2 medicament has been proven to induce dentin bridge formation, but an adequate sealing seems to be even more important that the capping material used. The purpose of this study was two fold: to assess the pulpal response after pulpal exposure by air abrasion and to evaluate the healing potential after using Ca(OH)2 medicament or Liner Bond II as a capping agent. Two hundred sixteen teeth from mixed-bred dogs were used in this study. The teeth were divided into three groups, A) pulpal exposure by air-abrasion followed by sealing of the cavity with Liner Bond II, B) pulpal exposure by air-abrasion and Ca(OH)2 pulp capping and C) pulpal exposure by high-speed followed by air-abrasion and Ca(OH)2 pulp capping as a control group. The animals were sacrificed after 7, 14, 30 and 60 days and a histopathological evaluation was undertaken. After applying Analysis of Variance to compare the groups, it was observed that at earlier observation periods, the inflammatory criteria near the exposure site were different among the groups. As time elapsed, the inflammation was resolved in the pulp tissue, however, the odontoblastic layer and the dentin bridge formation had a highly statistically significant difference (p<0.001) among the various groups at all observation periods. In addition, a positive correlation was observed between the organization of the odontoblastic layer and the dentin bridge formation mainly after 30 days. It could be concluded that dentin bridge formation could be achieved with the use of Ca(OH) or Liner Bond II as capping agent with an adequate sealing. However, the formation is delayed especially when Liner Bond II is used as capping agent.

  9. Rock Abrasion as Seen by the MSL Curiosity Rover: Insights on Physical Weathering on Mars

    NASA Astrophysics Data System (ADS)

    Bridges, N.; Day, M. D.; Le Mouelic, S.; Martin-Torres, F. J.; Newsom, H. E.; Sullivan, R. J., Jr.; Ullan, A.; Wiens, R. C.; Zorzano, M. P.

    2014-12-01

    Mars is a dry planet, with actively blowing sand in many regions. In the absence of stable liquid water and an active hydrosphere, rates of chemical weathering are slow, such that aeolian abrasion is a dominant agent of landscape modification where sand is present and winds above threshold occur at sufficient frequency. Reflecting this activity, ventifacts, rocks that have been abraded by windborne particles, and wind-eroded outcrops, are common. They provide invaluable markers of the Martian wind record and insight into climate and landscape modification. Ventifacts are distributed along the traverse of the Mars Science Laboratory Curiosity rover. They contain one or more diagnostic features and textures: Facets, keels, basal sills, elongated pits, scallops/flutes, grooves, rock tails, and lineations. Keels at the junction of facets are sharp enough to pose a hazard MSL's wheels in some areas. Geomorphic and textural patterns on outcrops indicate retreat of windward faces. Moonlight Valley and other depressions are demarcated by undercut walls and scree boulders, with the valley interiors containing fewer rocks, most of which show evidence for significant abrasion. Together, this suggests widening and undercutting of the valley walls, and erosion of interior rocks, by windblown sand. HiRISE images do not show any dark sand dunes in the traverse so far, in contrast to the large dune field to the south that is migrating up to 2 m per year. In addition, ChemCam shows that the rock Bathurst has a rind rich in mobile elements that would be removed in an abrading environment. This indicates that rock abrasion was likely more dominant in the past, a hypothesis consistent with rapid scarp retreat as suggested by the cosmogenic noble gases in Yellowknife Bay. Ventifacts and evidence for bedrock abrasion have also been found at the Pathfinder, Spirit, and Opportunity sites, areas, like the Curiosity traverse so far, that lack evidence for current high sand fluxes. Yardangs

  10. Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments

    PubMed Central

    RODRIGUES, Marcela Charantola; MONDELLI, Rafael Francisco Lia; OLIVEIRA, Gabriela Ulian; FRANCO, Eduardo Batista; BASEGGIO, Wagner; WANG, Linda

    2013-01-01

    Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. Material and Methods: Fifty (50) fragments of bovine enamel (15 mm x 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p≤0.05) which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p≤0.05). Results: Means and standard deviations of roughness and wear (mm) after all the promoted stages were: G1=7.26(1.81)/13.16(2.67), G2=2.02(0.62)/37.44(3.33), G3=1.81(0.91)/34.93(6.92), G4=1.92(0.29)/38.42(0.65) and G5=1.98(0.53)/33.45(2.66). At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. Conclusions: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear. PMID:23739863

  11. Understanding litter decomposition in drylands: Is litter abrasion an important abiotic factor?

    NASA Astrophysics Data System (ADS)

    Peterson, M.; Bravo-Garza, M. R.; Throop, H. L.; Duarte, L. C.

    2012-12-01

    Drylands comprise approximately 40% of global land cover and about 20% of global soil organic carbon (C) pool. Changes in dryland ecosystem processes, such as litter decomposition, could greatly influence global C cycling and climate change. Current models underestimate rates of litter decomposition in drylands, and little is known about the role and interactions of abiotic drivers in these systems. Research suggests leaf abrasion may play an important role on litter decomposition in drylands by increasing microbial activity or leaching. The Scrape Site at Jornada LTER was stripped of vegetation in 1991, leaving exposed soil that could serve as a source of sand particles to promote leaf abrasion on mesquite shrubs located downwind. This project examines the role that leaf abrasion, promoted in the field by wind erosion, and induced through laboratory simulations, will play in litter decomposition. We hypothesize that leaf abrasion will increase rates of litter decomposition due to facilitation of microbial colonization. Mesquite leaves were collected from two locations: down-wind from the Scrape Site and 80 meters away representing "field abraded" and "unabraded" treatments, respectively. For a "lab abraded" treatment, abrasion was performed by shaking leaves for 30 seconds with sand particles to simulate microscopic characteristics seen in "field abraded" treatment; this treatment resulted in an average leaf area loss of 3.267 %. Differences in decomposition rates among litter treatments were evaluated in a 16 week laboratory incubation. Litter was incubated at 22°C in airtight glass jars containing 50 g of soil (0.053 g water g-1 soil). Rapid colonization by fungi was apparent across treatments, but lab abraded litter showed the most abundant growth. Consequently, lab abraded litter treatment showed 20% and 30% times more accumulation of CO2 -C than field (P= 0.0008) and unabraded (P< 0.0001) litter treatments during the first 6 days of incubation. These results

  12. Model aids cuttings transport prediction

    SciTech Connect

    Gavignet, A.A. ); Sobey, I.J. )

    1989-09-01

    Drilling of highly deviated wells can be complicated by the formation of a thick bed of cuttings at low flow rates. The model proposed in this paper shows what mechanisms control the thickness of such a bed, and the model predictions are compared with experimental results.

  13. Cuts to science spending spared

    NASA Astrophysics Data System (ADS)

    Federal science funding was one area spared further cuts over the next 5 years when the House rejected the Penny-Kasich Deficit Plan by a vote of 219-213 on November 22. Known for its two House cosponsors Timothy Penny (D-Minn.) and John Kasich (R-Ohio), the plan called for additional cuts of $103 billion in federal spending over 5 years. The proposal was an amendment to HR3400, Clinton's spending-reduction bill, which would cut federal spending by over $11 billion in the next 5 years. HR3400 was passed by the House during the same vote.In addition to savings from President Clinton's plan to reduce the federal work force by 252,000, the Penny-Kasich amendment offered ninety proposals to cut federal spending. One of the major policy changes called for was the merging of the Departments of Energy and Commerce, NASA, the National Science Foundation, and the Office of Science and Technology Policy into a new Department of Science. This consolidation, said the plan's sponsors, “could result in $1 billion of reduced spending due to administrative consolidation and elimination of programmatic duplication.”

  14. Automated internal pipe cutting device

    DOEpatents

    Godlewski, William J.; Haffke, Gary S.; Purvis, Dale; Bashar, Ronald W.; Jones, Stewart D.; Moretti, Jr., Henry; Pimentel, James

    2003-01-21

    The invention is a remotely controlled internal pipe cutting device primarily used for cutting pipes where the outside of the pipe is inaccessible at the line where the cut is to be made. The device includes an axial ram within a rotational cylinder which is enclosed in a housing. The housing is adapted for attachment to an open end of the pipe and for supporting the ram and cylinder in cantilever fashion within the pipe. A radially movable cutter, preferably a plasma arc torch, is attached to the distal end of the ram. A drive mechanism, containing motors and mechanical hardware for operating the ram and cylinder, is attached to the proximal end of the housing. The ram and cylinder provide for moving the cutter axially and circumferentially, and a cable assembly attached to a remote motor provide for the movement of the cutter radially, within the pipe. The control system can be adjusted and operated remotely to control the position and movement of the cutter to obtain the desired cut. The control system can also provide automatic standoff control for a plasma arc torch.

  15. X-Z-Theta cutting method

    DOEpatents

    Bieg, L.F.

    1993-01-12

    A method for machining a workpiece. The method includes the use of a rotary cutting tool mounted on the end of a movable arm. The arm is adapted to move in a plane perpendicular to the axis of rotation of the cutting tool. The cutting tool has cutting teeth to cut chips of material off of the workpiece in a predetermined size and shape to facilitate better removal of the chips from the workpiece. The teeth can be of different type and length to permit the tool to both rough cut and finish cut the workpiece during machining. The total depth of cut is divided by the number of tool teeth, so that the longest tool always performs the finishing cut.

  16. Knife and impact cutting of lamb bone.

    PubMed

    King, M J

    1999-05-01

    The forces and hence fracture energies required to cut bone are presented in this paper and the merits of cutting with a high speed blade are considered. A plain knife blade was used to cut cancellous and compact lamb bone using three different methods. A microtome was used to produce a range of cut thicknesses which enabled the fracture energy to be separated into friction, surface fracture and plastic deformation energies. A tensile test machine was used to produce thicker off-cuts so that the energy required to cut through full sections of bone could be determined. A high speed rail gun was used to cut at speeds up to 130 m/s. The energy required to cut bone did not change with blade speed. However, the energies measured during the cutting varied over a wide range. In situations in which the surface of the cut bone exhibited a very uneven surface high energy was required, whereas when the resulting cut surface was planar the cutting energy was low. A light weight blade which impacts the bone at high speed will transmit a small impulse to the carcass which may be absorbed without transmitting strain to the muscle/connective tissue. This may allow the development of a high speed knife which will cut bone without excessively damaging the meat surrounding the cut. PMID:22062140

  17. Measurement of Cut Front Properties in Laser Cutting

    NASA Astrophysics Data System (ADS)

    Thombansen, Ulrich; Hermanns, Torsten; Molitor, Thomas; Pereira, Milton; Schulz, Wolfgang

    Cut-front properties are a key variable in laser-cutting and thus of major importance for self-optimization. Within the Cluster of Excellence at RWTH Aachen University, several achievements were made in setting up sensor-systems that provide information on the operating-point of this melt-based manufacturing process. These achievements contribute to a gradual increase in system-transparency which is seen as an enabler for self-optimization. Instead of searching for a single measurand to characterize the course of the process, an approach is being presented which establishesa surrogate criterion to allow determination of the current operating-point. In the depicted area, this is done by joining sources of information from process observation, determining boundary-conditions such as actual feed-rate and modeling of process-variables. Although process-variables like properties of the cutting-front are influenced through more than one process parameter, a concept for a sensor-system is reported showing the correlation between properties of the melt-front and the current feed-rate. The results are compared to a solution derived from process-simulation.

  18. Effect of Bioactive Glass air Abrasion on Shear Bond Strength of Two Adhesive Resins to Decalcified Enamel

    PubMed Central

    Eshghi, Alireza; Khoroushi, Maryam; Rezvani, Alireza

    2014-01-01

    Objective: Bioactive glass air abrasion is a conservative technique to remove initial decalcified tissue and caries. This study examined the shear bond strength of composite resin to sound and decalcified enamel air-abraded by bioactive glass (BAG) or alumina using etch-and-rinse and self-etch adhesives. Materials and Methods: Forty-eight permanent molars were root-amputated and sectioned mesiodistally. The obtained 96 specimens were mounted in acrylic resin; the buccal and lingual surfaces remained exposed. A demineralizing solution was used to decalcify half the specimens. Both sound and decalcified specimens were divided into two groups of alumina and bioactive glass air abrasion. In each group, the specimens were subdivided into two subgroups of Clearfil SE Bond or OptiBond FL adhesives (n=12). Composite resin cylinders were bonded on enamel surfaces cured and underwent thermocycling. The specimens were tested for shear bond strength. Data were analyzed using SPSS 16.0 and three-way ANOVA (α=0.05). Similar to the experimental groups, the enamel surface of one specimen underwent SEM evaluation. Results: No significant differences were observed in composite resin bond strength subsequent to alumina or bioactive glass air abrasion preparation techniques (P=0.987). There were no statistically significant differences between the bond strength of etch-and-rinse and self-etch adhesive groups (P=1). Also, decalcified or intact enamel groups had no significant difference (P=0.918). However, SEM analysis showed much less enamel irregularities with BAG air abrasion compared to alumina air abrasion. Conclusion: Under the limitations of this study, preparation of both intact and decalcified enamel surfaces with bioactive glass air abrasion results in similar bond strength of composite resin in comparison with alumina air abrasion using etch-&-rinse or self-etch adhesives. PMID:25628694

  19. Growth and wear of incisor and cheek teeth in domestic rabbits (Oryctolagus cuniculus) fed diets of different abrasiveness.

    PubMed

    Müller, Jacqueline; Clauss, Marcus; Codron, Daryl; Schulz, Ellen; Hummel, Jürgen; Fortelius, Mikael; Kircher, Patrick; Hatt, Jean-Michel

    2014-06-01

    Although patterns of tooth wear are crucial in palaeo-reconstructions, and dental wear abnormalities are important in veterinary medicine, experimental investigations on the relationship between diet abrasiveness and tooth wear are rare. Here, we investigated the effect of four different pelleted diets of increasing abrasiveness (due to both internal [phytoliths] and external abrasives [sand]) or whole grass hay fed for 2 weeks each in random order to 16 rabbits (Oryctolagus cuniculus) on incisor and premolar growth and wear, and incisor and cheek tooth length. Wear and tooth length differed between diets, with significant effects of both internal and external abrasives. While diet abrasiveness was linked to tooth length for all tooth positions, whole forage had an additional effect on upper incisor length only. Tooth growth was strongly related to tooth wear and differed correspondingly between diets and tooth positions. At 1.4-3.2 mm/week, the growth of cheek teeth measured in this study was higher than previously reported for rabbits. Dental abnormalities were most distinct on the diet with sand. This study demonstrates that concepts of constant tooth growth in rabbits requiring consistent wear are inappropriate, and that diet form (whole vs. pelleted) does not necessarily affect cheek teeth. Irrespective of the strong effect of external abrasives, internal abrasives have the potential to induce wear and hence exert selective pressure in evolution. Detailed differences in wear effects between tooth positions allow inferences about the mastication process. Elucidating feedback mechanisms that link growth to tooth-specific wear represents a promising area of future research.

  20. Using stream sediment lithology to explore the roles of abrasion and channel network structure in shaping downstream sediment yields

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Smith, M. E.; Pitlick, J.

    2012-12-01

    Both the flux and characteristics of stream sediment evolve downstream in response to variations in sediment supply, abrasion rate, and channel network structure. We use a simple erosion-abrasion mass balance to model the downstream evolution of sediment flux in two adjacent watersheds draining differing mixtures of soft and resistant rock types in the northern Rocky Mountains. Measurements of bed sediment grain size and lithology are used in conjunction with measured bed load and suspended load sediment fluxes to constrain the model. The results show that the downstream evolution in bed load flux and composition can be strongly influenced by subtle differences in underlying geology, which shapes both the abrasion characteristics and travel path lengths of individual rock types. In the Big Wood basin, abrasion rapidly reduces the size of soft sedimentary and volcanic rocks exposed in headwater areas, concentrating resistant granitic rocks in the stream bed and depressing bed load in favor of suspended load. Alternatively, in the North Fork Big Lost basin, volcanic and sedimentary lithologies are exposed throughout the catchment, and the bed material becomes dominated by erodible but resistant quartzitic sandstones. The result is a much higher bed load flux best modeled with modest abrasion rates. In both cases, the best-fit model can reproduce within 5% the composition of the stream bed substrate using realistic erosion and abrasion parameters. The results also demonstrate a strong linkage between modern hillslopes and channel systems even in these formerly glaciated landscapes, as the sediment signature of the primary streams reflects the systematic tapping of distinct source areas. While this work shows promise, measurement of the spatial patterns in the size and composition of bed and suspended load fluxes at locations throughout a channel network would better elucidate that relative importance of supply, sorting, and abrasion processes.