Science.gov

Sample records for point cutting tool

  1. Manual bamboo cutting tool.

    PubMed

    Bezerra, Mariana Pereira; Correia, Walter Franklin Marques; da Costa Campos, Fabio Ferreira

    2012-01-01

    The paper presents the development of a cutting tool guide, specifically for the harvest of bamboo. The development was made based on precepts of eco-design and ergonomics, for prioritizing the physical health of the operator and the maintenance of the environment, as well as meet specific requirements of bamboo. The main goal is to spread the use of bamboo as construction material, handicrafts, among others, from a handy, easy assembly and material available tool. PMID:22317613

  2. Application of high-rate cutting tools

    NASA Astrophysics Data System (ADS)

    Moriarty, John L., Jr.

    1989-03-01

    Widespread application of the newest high-rate cutting tools to the most appropriate jobs is slowed by the sheer magnitude of developments in tool types, materials, workpiece applications, and by the rapid pace of change. Therefore, a study of finishing and roughing sizes of coated carbide inserts having a variety of geometries for single point turning was completed. The cutting tools were tested for tool life, chip quality, and workpiece surface finish at various cutting conditions with medium alloy steel. An empirical wear-life data base was established, and a computer program was developed to facilitate technology transfer, assist selection of carbide insert grades, and provide machine operating parameters. A follow-on test program was implemented suitable for next generation coated carbides, rotary cutting tools, cutting fluids, and ceramic tool materials.

  3. Cutting tool form compensation system and method

    DOEpatents

    Barkman, W.E.; Babelay, E.F. Jr.; Klages, E.J.

    1993-10-19

    A compensation system for a computer-controlled machining apparatus having a controller and including a cutting tool and a workpiece holder which are movable relative to one another along a preprogrammed path during a machining operation utilizes a camera and a vision computer for gathering information at a preselected stage of a machining operation relating to the actual shape and size of the cutting edge of the cutting tool and for altering the preprogrammed path in accordance with detected variations between the actual size and shape of the cutting edge and an assumed size and shape of the cutting edge. The camera obtains an image of the cutting tool against a background so that the cutting tool and background possess contrasting light intensities, and the vision computer utilizes the contrasting light intensities of the image to locate points therein which correspond to points along the actual cutting edge. Following a series of computations involving the determining of a tool center from the points identified along the tool edge, the results of the computations are fed to the controller where the preprogrammed path is altered as aforedescribed. 9 figures.

  4. Cutting tool form compensaton system and method

    DOEpatents

    Barkman, William E.; Babelay, Jr., Edwin F.; Klages, Edward J.

    1993-01-01

    A compensation system for a computer-controlled machining apparatus having a controller and including a cutting tool and a workpiece holder which are movable relative to one another along a preprogrammed path during a machining operation utilizes a camera and a vision computer for gathering information at a preselected stage of a machining operation relating to the actual shape and size of the cutting edge of the cutting tool and for altering the preprogrammed path in accordance with detected variations between the actual size and shape of the cutting edge and an assumed size and shape of the cutting edge. The camera obtains an image of the cutting tool against a background so that the cutting tool and background possess contrasting light intensities, and the vision computer utilizes the contrasting light intensities of the image to locate points therein which correspond to points along the actual cutting edge. Following a series of computations involving the determining of a tool center from the points identified along the tool edge, the results of the computations are fed to the controller where the preprogrammed path is altered as aforedescribed.

  5. A Flexure-Based Tool Holder for Sub-(micro)m Positioning of a Single Point Cutting Tool on a Four-axis Lathe

    SciTech Connect

    Bono, M J; Hibbard, R L

    2005-12-05

    A tool holder was designed to facilitate the machining of precision meso-scale components with complex three-dimensional shapes with sub-{micro}m accuracy on a four-axis lathe. A four-axis lathe incorporates a rotary table that allows the cutting tool to swivel with respect to the workpiece to enable the machining of complex workpiece forms, and accurately machining complex meso-scale parts often requires that the cutting tool be aligned precisely along the axis of rotation of the rotary table. The tool holder designed in this study has greatly simplified the process of setting the tool in the correct location with sub-{micro}m precision. The tool holder adjusts the tool position using flexures that were designed using finite element analyses. Two flexures adjust the lateral position of the tool to align the center of the nose of the tool with the axis of rotation of the B-axis, and another flexure adjusts the height of the tool. The flexures are driven by manual micrometer adjusters, each of which provides a minimum increment of motion of 20 nm. This tool holder has simplified the process of setting a tool with sub-{micro}m accuracy, and it has significantly reduced the time required to set a tool.

  6. 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.

  7. 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.

  8. Advanced cryogenics for cutting tools. Final report

    SciTech Connect

    Lazarus, L.J.

    1996-10-01

    The purpose of the investigation was to determine if cryogenic treatment improved the life and cost effectiveness of perishable cutting tools over other treatments or coatings. Test results showed that in five of seven of the perishable cutting tools tested there was no improvement in tool life. The other two tools showed a small gain in tool life, but not as much as when switching manufacturers of the cutting tool. The following conclusions were drawn from this study: (1) titanium nitride coatings are more effective than cryogenic treatment in increasing the life of perishable cutting tools made from all cutting tool materials, (2) cryogenic treatment may increase tool life if the cutting tool is improperly heat treated during its origination, and (3) cryogenic treatment was only effective on those tools made from less sophisticated high speed tool steels. As a part of a recent detailed investigation, four cutting tool manufacturers and two cutting tool laboratories were queried and none could supply any data to substantiate cryogenic treatment of perishable cutting tools.

  9. Cutting Tool For Shaving Weld Beads

    NASA Technical Reports Server (NTRS)

    Hoffman, David S.; Mcferrin, David C.; Daniel, Ronald L., Jr.; Coby, John B., Jr.; Dawson, Sidney G.

    1995-01-01

    Cutting tool proposed for use in shaving weld beads flush with adjacent surfaces of weldments. Modified version of commercial pneumatically driven rotary cutting tool, cutting wheel of which turns at speeds sufficient for machining nickel alloys, titanium, and stainless steels. Equipped with forward-mounted handle and rear-mounted skid plate to maximize control and reduce dependence on skill of technician.

  10. Ductile cutting of silicon microstructures with surface inclination measurement and compensation by using a force sensor integrated single point diamond tool

    NASA Astrophysics Data System (ADS)

    Chen, Yuan-Liu; Cai, Yindi; Shimizu, Yuki; Ito, So; Gao, Wei; Ju, Bing-Feng

    2016-02-01

    This paper presents a measurement and compensation method of surface inclination for ductile cutting of silicon microstructures by using a diamond tool with a force sensor based on a four-axis ultra-precision lathe. The X- and Y-directional inclinations of a single crystal silicon workpiece with respect to the X- and Y-motion axes of the lathe slides were measured respectively by employing the diamond tool as a touch-trigger probe, in which the tool-workpiece contact is sensitively detected by monitoring the force sensor output. Based on the measurement results, fabrication of silicon microstructures can be thus carried out directly along the tilted silicon workpiece by compensating the cutting motion axis to be parallel to the silicon surface without time-consuming pre-adjustment of the surface inclination or turning of a flat surface. A diamond tool with a negative rake angle was used in the experiment for superior ductile cutting performance. The measurement precision by using the diamond tool as a touch-trigger probe was investigated. Experiments of surface inclination measurement and ultra-precision ductile cutting of a micro-pillar array and a micro-pyramid array with inclination compensation were carried out respectively to demonstrate the feasibility of the proposed method.

  11. Defect characterization in the diamond cutting tools

    SciTech Connect

    Zeren, Muzaffer . E-mail: zeren@kou.edu.tr; Karagoez, Sadi

    2006-08-15

    In this study, a general defect characterization in the diamond cutting tools used in natural stone cutting has been investigated. Transverse rupture tests were carried out with different matrix and diamond compositions. In these defect characterization studies on diamond cutting tool materials various microstructural analyses were performed using the techniques of light microscopy (LM), scanning electron microscopy (SEM), energy-dispersed X-ray spectrography (EDX) and image analysis (IA)

  12. Vee-notch tool cuts specimens

    NASA Technical Reports Server (NTRS)

    Spier, R. A.

    1970-01-01

    Triangular cutting tool uses carbide tips for notching heat-treated or abrasive materials, and alloys subjected to high structural stresses. The tool is rigidly mounted in a slot of mating contour to prevent deflection during cutting of tensile specimens. No other expensive machine equipment is required.

  13. An FMS Dynamic Production Scheduling Algorithm Considering Cutting Tool Failure and Cutting Tool Life

    NASA Astrophysics Data System (ADS)

    Setiawan, A.; Wangsaputra, R.; Martawirya, Y. Y.; Halim, A. H.

    2016-02-01

    This paper deals with Flexible Manufacturing System (FMS) production rescheduling due to unavailability of cutting tools caused either of cutting tool failure or life time limit. The FMS consists of parallel identical machines integrated with an automatic material handling system and it runs fully automatically. Each machine has a same cutting tool configuration that consists of different geometrical cutting tool types on each tool magazine. The job usually takes two stages. Each stage has sequential operations allocated to machines considering the cutting tool life. In the real situation, the cutting tool can fail before the cutting tool life is reached. The objective in this paper is to develop a dynamic scheduling algorithm when a cutting tool is broken during unmanned and a rescheduling needed. The algorithm consists of four steps. The first step is generating initial schedule, the second step is determination the cutting tool failure time, the third step is determination of system status at cutting tool failure time and the fourth step is the rescheduling for unfinished jobs. The approaches to solve the problem are complete-reactive scheduling and robust-proactive scheduling. The new schedules result differences starting time and completion time of each operations from the initial schedule.

  14. Study on optimal surface property of WC-Co cutting tool for aluminium alloy cutting

    NASA Astrophysics Data System (ADS)

    Nizar, Mohd; Arimatsu, Naoya; Kawamitsu, Hiroshi; Takai, Kazuteru; Fukumoto, Masahiro

    2016-02-01

    The light weight property as well as high corrosion resistance of aluminium alloy has increased their demand especially in automobile industries. Aluminium alloy as a matter of fact has a low melting point and high ductility that severely adhere to the cutting tool surface and cause deterioration of chip evacuation. This problem often resulting in tools breakage. In this paper, in order to impart functions of anti-adhesion, we propose a technique by controlling the grinding marks micro texture on the tool surface by using the blast polishing treatment without any coating technologies. The results show that the tool which underwent polishing treatment reduces the cutting force as well as the aluminium adherence during the initial cutting process, and become worst as the process cutting continues. These results indicate that grinding mark texture improves the anti-adhesion by reducing the contact area during cutting and provide storage for the lubricant. In addition, too much polishing on the tool surface may remove these textures and resultantly worsen the tool performance.

  15. Robotic Tool For Tightening And Cutting

    NASA Technical Reports Server (NTRS)

    Cooney, Earl T.

    1989-01-01

    Robot end effector designed for tightening tube couplers and for cutting tubes. Tool operable by simple movements and thus manipulated by technician wearing heavy protective clothing. Operates on principle of worm and pinion gear. Intended for use in building structures in space, end effector also used as hand tool for assembling truss structures for terrestrial buildings, tents, and oil rigs. Also used in place of pipe wrench in plumbing work.

  16. Testing Of Choiced Ceramics Cutting Tools At Irregular Interrupted Cut

    NASA Astrophysics Data System (ADS)

    Kyncl, Ladislav; Malotová, Šárka; Nováček, Pavel; Nicielnik, Henryk; Šoková, Dagmar; Hemžský, Pavel; Pitela, David; Holubjak, Jozef

    2015-12-01

    This article discusses the test of removable ceramic cutting inserts during machining irregular interrupted cut. Tests were performed on a lathe, with the preparation which simulated us the interrupted cut. By changing the number of plates mounted in a preparation it simulate us a regular or irregular interrupted cut. When with four plates it was regular interrupted cut, the remaining three variants were already irregular cut. It was examined whether it will have the irregular interrupted cutting effect on the insert and possibly how it will change life of inserts during irregular interrupted cut (variable delay between shocks).

  17. More About Cutting Tool For Shaving Weld Beads

    NASA Technical Reports Server (NTRS)

    Oelgoetz, Peter A.; Davis, William M.

    1996-01-01

    Report describes modification and testing of proposed tool discussed in "Cutting Tool For Shaving Weld Beads" (MFS-30056). Modified version of commercial pneumatically driven rotary cutting tool removes such hard metals as nickel alloys, titanium, and stainless steels.

  18. Cutting Properties and Wearing Process of Diamond Film Coated Tools in the Dry-Cutting

    NASA Astrophysics Data System (ADS)

    Zhong, Qimao

    Dry cutting can eliminate a series of negative effects of coolant. Based on tribology principle of coated tool, diamond film coated tool is used to cut the same workpiece under the conditions of dry-cutting and coolant. The tool's cutting properties and wear mechanism are studied by tests. Results imply that this coated tool will be applied more widely day by day in the dry-cutting.

  19. Tool for cutting insulation from electrical cables

    DOEpatents

    Harless, Charles E.; Taylor, Ward G.

    1978-01-01

    This invention is an efficient hand tool for precisely slitting the sheath of insulation on an electrical cable--e.g., a cable two inches in diameter--in a manner facilitating subsequent peeling or stripping of the insulation. The tool includes a rigid frame which is slidably fitted on an end section of the cable. The frame carries a rigidly affixed handle and an opposed, elongated blade-and-handle assembly. The blade-and-handle assembly is pivotally supported by a bracket which is slidably mounted on the frame for movement toward and away from the cable, thus providing an adjustment for the depth of cut. The blade-and-handle assembly is mountable to the bracket in two pivotable positions. With the assembly mounted in the first position, the tool is turned about the cable to slit the insulation circumferentially. With the assembly mounted in the second position, the tool is drawn along the cable to slit the insulation axially. When cut both circumferentially and axially, the insulation can easily be peeled from the cable.

  20. Pipe cutting tool is useful in limited space

    NASA Technical Reports Server (NTRS)

    Headley, C. A.; Jones, D. D.

    1966-01-01

    Portable pipe cutting tool is used in areas of limited space. The pipe is clamped in the tool and then cut by a rotating cutter assembly that is internally connected to a drive shaft engaged in the chuck of a portable electric drill. The tool is held in a fixed position during the cutting operation.

  1. Accelerometer Cut-Points and Youth Physical Activity Prevalence

    ERIC Educational Resources Information Center

    Mota, Jorge; Valente, Monica; Aires, Luisa; Silva, Pedro; Santos, Maria Paula; Ribeiro, Jose Carlos

    2007-01-01

    The purpose of this study was twofold: first, to examine the effects of specific cut-off scoring points (on the estimated prevalence of meeting health-related guidelines for physical activity in youth) and, second, to document the differences in gender physical activity patterns according to two different cut-off points. The sample comprised 62…

  2. Laser Cutting of Leather: Tool for Industry or Designers?

    NASA Astrophysics Data System (ADS)

    Stepanov, Alexander; Manninen, Matti; Pärnänen, Inni; Hirvimäki, Marika; Salminen, Antti

    Currently technologies which are applied for leather cutting include slitting knifes, die press techniques and manual cutting. Use of laser technology has grown significantly during recent years due to number of advantages over conventional cutting methods; flexibility, high production speed, possibility to cut complex geometries, easier cutting of customized parts, and less leftovers of leather makes laser cutting more and more economically attractive to apply for leather cutting. Laser technology provides advantages in cutting complex geometries, stable cutting quality and possibility to utilize leather material in economically best way. Constant quality is important in industrial processes and laser technology fulfills this requirement: properly chosen laser cutting parameters provides identical cuts. Additionally, laser technology is very flexible in terms of geometries: complex geometries, individual designs, prototypes and small scale products can be manufactured by laser cutting. Variety of products, which needed to be cut in small volumes, is also the application where laser cutting can be more beneficial due to possibility to change production from one product to another only by changing geometry without a need to change cutting tool. Disadvantages of laser processing include high initial investment costs and some running costs due to maintenance and required gas supply for the laser. Higher level of operator's expertise is required due to more complicated machinery in case of laser cutting. This study investigates advantages and disadvantages of laser cutting in different areas of application and provides comparison between laser cutting and mechanical cutting of leather.

  3. Decorating Cutting as New Approach to Machine Tool System Dynamics

    NASA Astrophysics Data System (ADS)

    Murcinkova, Zuzana; Vasilko, Karol

    2014-12-01

    The paper presents so called decorating cutting focused on turning. It uses self-excited vibrations that are typical for turning and other types of cutting operations. The decorating turning do not utilize setting of unstable technological conditions of cutting process but it actively use the acting of cutting force on machine tool without generation of unwanted chatter vibrations. The special tool fixture was developed to utilize self-excited vibrations invoked by periodical changeability of cutting force by cutting process itself. Thus the typical texture of surface appears. The various macro/micro-textures of surfaces can be applied either for decorating purpose or for better holding of oil film.

  4. Cutting Tool Wear After Pulsed Laser Processing in Air

    NASA Astrophysics Data System (ADS)

    Yares'ko, S. I.

    2014-01-01

    We have ascertained the influence of the oxide film formed on the surface of the laser-processed zone of tool steels by irradiation in air on the wear of the cutting tool. It has been shown that laser pulsed processing makes it possible to influence actively the process of its wear. The presence of the oxide film increases the wear stability of the tool in a wide range of cutting speeds, widens the range of cutting regimes in which its least wear is achieved, and minimizes the wear rate. Cutting regimes, in which the highest efficiency of the irradiated tool is achieved, have been established.

  5. Surface dimpling on rotating work piece using rotation cutting tool

    SciTech Connect

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  6. Threaded pilot insures cutting tool alignment

    NASA Technical Reports Server (NTRS)

    Goldman, R.; Schneider, W. E.

    1966-01-01

    Threaded pilot allows machining of a port component, or boss, after the reciprocating hole has been threaded. It is used to align cutting surfaces with the boss threads, thus insuring precision alignment.

  7. Generalized interactions using virtual tools within the spring framework: cutting

    NASA Technical Reports Server (NTRS)

    Montgomery, Kevin; Bruyns, Cynthia D.

    2002-01-01

    We present schemes for real-time generalized mesh cutting. Starting with the a basic example, we describe the details of implementing cutting on single and multiple surface objects as well as hybrid and volumetric meshes using virtual tools with single and multiple cutting surfaces. These methods have been implemented in a robust surgical simulation environment allowing us to model procedures ranging from animal dissection to cleft lip correction.

  8. Nitride and carbide coatings for high speed steel cutting tools

    SciTech Connect

    Fenske, G.R.

    1988-01-01

    Hard nitride and carbide coatings of Ti, Zr, and Hf were deposited by physical vapor deposition processes on high-speed steel cutting tools to determine their effectiveness in improving the wear properties of the inserts and increasing cutting-tool performance. A collaborative research program involving industrial, university, and government laboratories was established to develop coating processes and tool wear models, to characterize the coating properties and the effect of process parameters on the coating properties, and to evaluate the cutting performance of coated inserts. Two coating processes were selected for investigation: high-rate reactive sputtering and activated reactive evaporation. The lifetimes of coated inserts were extended 2 to 10 times, depending on the coating composition and process. Analysis of the wear modes that occurred during the cutting tests indicated that the coatings failed by fracture after plastic deformation of the underlying substrate occurred as a result of substrate softening at the high cutting speeds. 14 refs., 9 figs., 1 tab.

  9. Ultrasonic excitation affects friction interactions between food materials and cutting tools.

    PubMed

    Schneider, Yvonne; Zahn, Susann; Schindler, Claudia; Rohm, Harald

    2009-06-01

    In the food industry, ultrasonic cutting is used to improve separation by a reduction of the cutting force. This reduction can be attributed to the modification of tool-workpiece interactions at the cutting edge and along the tool flanks because of the superposition of the cutting movement with ultrasonic vibration of the cutting tool. In this study, model experiments were used to analyze friction between the flanks of a cutting tool and the material to be cut. Friction force at a commercial cutting sonotrode was quantified using combined cutting-friction experiments, and sliding friction tests were carried out by adapting a standard draw-off assembly and using an ultrasonic welding sonotrode as sliding surface. The impact of material parameters, ultrasonic amplitude, and the texture of the contacting food surface on friction force was investigated. The results show that ultrasonic vibration significantly reduces the sliding friction force. While the amplitude showed no influence within the tested range, the texture of the contact surface of the food affects the intensity of ultrasonic transportation effects. These effects are a result of mechanical interactions and of changes in material properties of the contact layer, which are induced by the deformation of contact points, friction heating and absorption heating because of the dissipation of mechanical vibration energy. PMID:19342070

  10. Production Recesses for Replaceable Cutting Inserts of Milling Tools

    NASA Astrophysics Data System (ADS)

    Kousal, Lukáš; Sadílek, Marek

    2014-12-01

    This article describes the production of recesses for replaceable cutting inserts of milling tools. The recess manufacture is exemplified on a D20 shanktype milling cutter with three replaceable cutting inserts. A new production technology and its operating cycle are demonstrated. A com-parison of the old and the new technologies shows the percentage saving of change cycles and used tools, including overall evaluation of the tech-nology.

  11. Cutting tool study: 21-6-9 stainless steel

    SciTech Connect

    McManigle, A.P.

    1992-07-29

    The Rocky Flats Plant conducted a study to test cermet cutting tools by performing machinability studies on War Reserve product under controlled conditions. The purpose of these studies was to determine the most satisfactory tools that optimize tool life, minimize costs, improve reliability and chip control, and increase productivity by performing the operations to specified Accuracies. This study tested three manufacturers` cermet cutting tools and a carbide tool used previously by the Rocky Flats Plant for machining spherical-shaped 21-6-9 stainless steel forgings (Figure 1). The 80-degree diamond inserts were tested by experimenting with various chip-breaker geometries, cutting speeds, feedrates, and cermet grades on the outside contour roughing operation. The cermets tested were manufactured by Kennametal, Valenite, and NTK. The carbide tool ordinarily used for this operation is manufactured by Carboloy. Evaluation of tho tools was conducted by investigating the number of passes per part and parts per insert, tool wear, cutting time, tool life, surface finish, and stem taper. Benefits to be gained from this study were: improved part quality, better chip control, increased tool life and utilization, and greater fabrication productivity. This was to be accomplished by performing the operation to specified accuracies within the scope of the tools tested.

  12. Cutting tool study: 21-6-9 stainless steel

    SciTech Connect

    McManigle, A.P.

    1992-07-29

    The Rocky Flats Plant conducted a study to test cermet cutting tools by performing machinability studies on War Reserve product under controlled conditions. The purpose of these studies was to determine the most satisfactory tools that optimize tool life, minimize costs, improve reliability and chip control, and increase productivity by performing the operations to specified Accuracies. This study tested three manufacturers' cermet cutting tools and a carbide tool used previously by the Rocky Flats Plant for machining spherical-shaped 21-6-9 stainless steel forgings (Figure 1). The 80-degree diamond inserts were tested by experimenting with various chip-breaker geometries, cutting speeds, feedrates, and cermet grades on the outside contour roughing operation. The cermets tested were manufactured by Kennametal, Valenite, and NTK. The carbide tool ordinarily used for this operation is manufactured by Carboloy. Evaluation of tho tools was conducted by investigating the number of passes per part and parts per insert, tool wear, cutting time, tool life, surface finish, and stem taper. Benefits to be gained from this study were: improved part quality, better chip control, increased tool life and utilization, and greater fabrication productivity. This was to be accomplished by performing the operation to specified accuracies within the scope of the tools tested.

  13. 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.

  14. Modeling of tool path for the CNC sheet cutting machines

    NASA Astrophysics Data System (ADS)

    Petunin, Aleksandr A.

    2015-11-01

    In the paper the problem of tool path optimization for CNC (Computer Numerical Control) cutting machines is considered. The classification of the cutting techniques is offered. We also propose a new classification of toll path problems. The tasks of cost minimization and time minimization for standard cutting technique (Continuous Cutting Problem, CCP) and for one of non-standard cutting techniques (Segment Continuous Cutting Problem, SCCP) are formalized. We show that the optimization tasks can be interpreted as discrete optimization problem (generalized travel salesman problem with additional constraints, GTSP). Formalization of some constraints for these tasks is described. For the solution GTSP we offer to use mathematical model of Prof. Chentsov based on concept of a megalopolis and dynamic programming.

  15. Shock synthesized and static sintered boron nitride cutting tool

    NASA Astrophysics Data System (ADS)

    Araki, M.; Kuroyama, Y.

    1986-05-01

    Shock synthesis of wBN (wurtzite phase boron nitride) on an industrial scale was achieved by Nippon Oil & Fats and Showa Denko in 1971. It seemed that the resultant wBN powder might display excellent qualities as a cutting tool material when it was sintered under very high static pressure and temperature because of its polycrystalline nature. Attempts to produce a wBN cutting tool material were commenced by the Tokyo Institute of Technology and Nippon Oil & Fats in 1976 and commercially available wBN cutting tools were first sold in 1980. Meanwhile, a new type of explosion chamber designed to eliminate explosion sound and earth vibration problems, novel high pressure vessels and other peripheral apparatuses have been developed. Now, WURZIN (trademark for the wBN cutting tool) is used in many aspects of the steel cutting field because it is durable when cutting various steels from mild steels to superalloys under high speed, interrupt and precision cutting conditions.

  16. 10. CANAL CUT THROUGH SHALE BEDROCK ON PROMINENT POINT, LOOKING ...

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

    10. CANAL CUT THROUGH SHALE BEDROCK ON PROMINENT POINT, LOOKING NORTH-NORTHEAST. NOTE CONCRETE ABUTMENTS PROBABLY INSTALLED IN 1935 TO PREVENT WATER FROM ESCAPING THROUGH A CANAL BANK BREACH. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  17. Diamond tool wear vs cutting distance on electroless nickel mirrors

    SciTech Connect

    Syn, C.K.; Taylor, J.S.; Donaldson, R.R.

    1986-10-14

    Wear data are presented for diamond tools cutting electroless nickel (eNi) for cut lengths up to 70,000 ft (13 miles). Two tools having different infrared absorption characteristics were used to cut an eNi preparation that had yielded minimum values for surface roughness and tool wear rate in a previous study. The data include Talystep measurement of the rms amplitude of the feed-marks versus cumulative cutting distance, representative examples of shape changes for the feed-mark profiles, SEM and optical micrographs of the tool rake and flank face wear zones, and measurements of the cutting edge profile and edge recession distance by a tool-nose replication technique. Feed-mark roughness values were found to increase from 5 to 90 A rms over the duration of the test, with an associated edge recession of about 1000 A and the development of a periodic tool edge grooving indicative of burnishing of the part surface. The ir absorption data successfully predicted the order of the two tools in terms of wear rate and fracture toughness.

  18. Diamond Tool Wear Vs. Cutting Distance On Electroless Nickel Mirrors

    NASA Astrophysics Data System (ADS)

    Syn, C. K.; Taylor, J. S.; Donaldson, R. R.

    1987-02-01

    Wear data are presented for diamond tools cutting electroless nickel (eNi) for cut lengths up to 70,000 ft (13 miles). Two tools having different infrared absorption characteristics were used to cut an eNi preparation that had yielded minimum values for surface roughness and tool wear rate in a previous study. The data include Talystep measurement of the rms amplitude of the feed-marks versus cumulative cutting distance, representative examples of shape changes for the feed-mark profiles, SEM and optical micrographs of the tool rake and flank face wear zones, and measurements of the cutting edge profile and edge recession distance by a tool-nose replication technique. Feed-mark roughness values were found to increase from 5 to 90 A rms over the duration of the test, with an associated edge recession of about 1000 A and the development of a periodic tool edge grooving indicative of burnishing of the part surface. The IR absorption data successfully predicted the order of the two tools in terms of wear rate and fracture toughness.

  19. Tool post modification allows easy turret lathe cutting-tool alignment

    NASA Technical Reports Server (NTRS)

    Fouts, L.

    1966-01-01

    Modified tool holder and tool post permit alignment of turret lathe cutting tools on the center of the spindle. The tool is aligned with the spindle by the holder which is kept in position by a hydraulic lock in feature of the tool post. The tool post is used on horizontal and vertical turret lathes and other engine lathes.

  20. Hardening effect on machined surface for precise hard cutting process with consideration of tool wear

    NASA Astrophysics Data System (ADS)

    Yue, Caixu; Liu, Xianli; Ma, Jing; Liu, Zhaojing; Liu, Fei; Yang, Yongheng

    2014-11-01

    During hard cutting process there is severe thermodynamic coupling effect between cutting tool and workpiece, which causes quenching effect on finished surfaces under certain conditions. However, material phase transformation mechanism of heat treatment in cutting process is different from the one in traditional process, which leads to changes of the formation mechanism of damaged layer on machined workpiece surface. This paper researches on the generation mechanism of damaged layer on machined surface in the process of PCBN tool hard cutting hardened steel Cr12MoV. Rules of temperature change on machined surface and subsurface are got by means of finite element simulation. In phase transformation temperature experiments rapid transformation instrument is employed, and the effect of quenching under cutting conditions on generation of damaged layer is revealed. Based on that, the phase transformation points of temperature under cutting conditions are determined. By experiment, the effects of cutting speed and tool wear on white layer thickness in damaged layer are revealed. The temperature distribution law of third deformation zone is got by establishing the numerical prediction model, and thickness of white layer in damaged layer is predicted, taking the tool wear effect into consideration. The experimental results show that the model prediction is accurate, and the establishment of prediction model provides a reference for wise selection of parameters in precise hard cutting process. For the machining process with high demanding on surface integrity, the generation of damaged layer on machined surface can be controlled precisely by using the prediction model.

  1. Validation of tool mark analysis of cut costal cartilage.

    PubMed

    Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Peters, Charles

    2012-03-01

    This study was designed to establish the potential error rate associated with the generally accepted method of tool mark analysis of cut marks in costal cartilage. Three knives with different blade types were used to make experimental cut marks in costal cartilage of pigs. Each cut surface was cast, and each cast was examined by three analysts working independently. The presence of striations, regularity of striations, and presence of a primary and secondary striation pattern were recorded for each cast. The distance between each striation was measured. The results showed that striations were not consistently impressed on the cut surface by the blade's cutting edge. Also, blade type classification by the presence or absence of striations led to a 65% misclassification rate. Use of the classification tree and cross-validation methods and inclusion of the mean interstriation distance decreased the error rate to c. 50%. PMID:22081951

  2. Conventional sintering of diamond cutting tool used in natural stone cutting

    NASA Astrophysics Data System (ADS)

    Selvi, Ekin; Topaloglu, Ferit; Tazegul, Onur; Kayali, E. Sabri

    2013-12-01

    Diamond Tools, used in natural stone cutting, is produced commonly by powder metallurgy with Spark Plasma Sintering (SPS) and/or Conventional Sintering (CS). Co is generally used as metal matrices because of their bonding strength and optimum wear rate. However, because of cobalt's high prices, other alloying elements are also used to decrease the cost of diamond tools. Aim of this study is to compare mechanical, physical, microstructural properties of diamond cutting tools made of Co-Ni-Cu-Sn matrix, produced by Spark Plasma Sintering and Conventional Sintering. Spark Plasma Sintering performed at 850 °C and Conventional Sintering performed at various temperatures (between 950 and 1150 °C) and times (1 to 4 hours). Then various properties (density, hardness, compression strength) of Conventional Sintered and Spark Plasma Sintered tools were investigated and compared. The experimental results showed that SPS tools have much better properties than CS tools.

  3. Hand-Grip Strength Cut-Points to Screen Older Persons at Risk for Mobility Limitation

    PubMed Central

    Sallinen, Janne; Stenholm, Sari; Rantanen, Taina; Heliövaara, Markku; Sainio, Päivi; Koskinen, Seppo

    2010-01-01

    Objectives To determine optimal hand-grip strength cut-points for increased likelihood for mobility limitation among older people and to study whether these cut-points differ according to body mass index (BMI). Design and setting Cross-sectional analysis of data collected in the Finnish population-based Health 2000 Survey. Participants and measurements 1 084 men and 1 562 women aged 55 years and older with complete data on anthropometry, hand-grip strength and self-reported mobility. Mobility limitation was defined as difficulties in walking 0.5-km or climbing stairs. Receiver Operating Characteristics analysis was used to estimate hand-grip strength cut-points for increased likelihood for mobility limitation. Results The overall hand-grip strength cut-points for increased likelihood for mobility limitation were 37 kg (sensitivity 62% and specificity 76%) for men and 21 kg (67% and 73%) for women. Hand-grip strength by BMI interaction on mobility limitation was significant among men (p = 0.022), while no such interaction was observed among women (p = 0.156). Among men, most optimal cut-offs were 33 kg (73% and 79%) for normal-weight men, 39 kg (67% and 71%) for overweight men and 40 kg (57% and 68%) for obese men. Among women, BMI-specific hand-grip strength cut-off values did not markedly increase accuracy over the overall cut-off value. Conclusion Hand-grip strength test is a useful tool to identify persons with increased risk for mobility limitation. Among men, the hand-grip strength cut-points for mobility increased along with BMI, while among women only one hand-grip strength threshold was identified. PMID:20863331

  4. 3D cutting tool inspection system and its key technologies

    NASA Astrophysics Data System (ADS)

    Du, X. M.; Chen, T.; Zou, X. J.; Harding, K. G.

    2009-08-01

    Cutting tools are an essential component used in manufacturing parts for different products. Many cutting tools are manufactured with complex geometric shapes and sharp and/or curved edges. As such, maintaining quality control of cutting tools during their fabrication may be essential to controlling the quality of components manufactured using the cutting tools. In this paper, a 3D cutting tool inspection system, is presented. The architecture of the system, the cutter inspection workflow and some key technologies are discussed. The relative key technologies include two aspects. The first aspect is the system extrinsic self-calibration method for ensuring the system accuracy. This paper will elaborate on how to calibrate the orientation and location of the rotary stage in the coordination system, including the relative relationship between the axis of the chuck used to hold the tool and the rotary axis used to position the tool, along with the relative relationship between Z stage and rotary axis. Further, this paper will analyze self-calibration solutions for separately correcting the error of the squareness and optical measuring beam and the error of the alignment between a side scan and a tip scan. The second aspect this paper will address is a method of scan planning for automatic and effective data collection. Tool measurement planning plays a big role in saving tool measurement time, improving data accuracy, as well as ensuring data completeness. Ths paper will present a round-part oriented measurement method that includes coarse/fine section scans that aim at getting 2D section geometry in a progressive manner, covering the key sharp/curved edge areas, and the side helical scan combined with the tip round scan for shape-simulated full geometry capture. Finally, this paper will present experimental results and some field tests data.

  5. Diamond tool wear detection method using cutting force and its power spectrum analysis in ultra-precision fly cutting

    NASA Astrophysics Data System (ADS)

    Zhang, G. Q.; To, S.

    2014-08-01

    Cutting force and its power spectrum analysis was thought to be an effective method monitoring tool wear in many cutting processes and a significant body of research has been conducted on this research area. However, relative little similar research was found in ultra-precision fly cutting. In this paper, a group of experiments were carried out to investigate the cutting forces and its power spectrum characteristics under different tool wear stages. Result reveals that the cutting force increases with the progress of tool wear. The cutting force signals under different tool wear stages were analyzed using power spectrum analysis. The analysis indicates that a characteristic frequency does exist in the power spectrum of the cutting force, whose power spectral density increases with the increasing of tool wear level, this characteristic frequency could be adopted to monitor diamond tool wear in ultra-precision fly cutting.

  6. Determining Cut-Off Points for the Dental Fear Survey

    PubMed Central

    Oliveira, Maurício Antônio; Bendo, Cristiane Baccin; Paiva, Saul Martins; Vale, Miriam Pimenta; Serra-Negra, Júnia Maria

    2015-01-01

    Objective. To determine a high fear cut-off point score for the Dental Fear Survey (DFS) using a single-item self-report questionnaire. Methods. The DFS, a 20-item questionnaire assessing fear of dental treatment, was completed by 1,256 participants with a mean age of 22.3 years (SD = 5.1). Another self-report questionnaire was used to collect data on previous dental experiences. A high fear cut-off point score was determined by calculating the receiver operating characteristic (ROC) curve for the DFS. Descriptive statistics and multinomial logistic regression were calculated; a significance level of p < 0.05 was used for all tests. Results. The ROC curve indicated that a DFS score ≥53 corresponds to a sensitivity of 88.9% and a specificity of 92.5%. Most participants (n = 895; 71.5%) reported no fear of going to the dentist. There was significant association between DFS score and fear assessed with the question “Are you fearful of going to the dentist?” (p < 0.001). Conclusion. A cut-off point of 53 on the DFS total score represents the best compromise between sensitivity and specificity and can be used to predict high dental fear. PMID:26491721

  7. Process Damping and Cutting Tool Geometry in Machining

    NASA Astrophysics Data System (ADS)

    Taylor, C. M.; Sims, N. D.; Turner, S.

    2011-12-01

    Regenerative vibration, or chatter, limits the performance of machining processes. Consequences of chatter include tool wear and poor machined surface finish. Process damping by tool-workpiece contact can reduce chatter effects and improve productivity. Process damping occurs when the flank (also known as the relief face) of the cutting tool makes contact with waves on the workpiece surface, created by chatter motion. Tool edge features can act to increase the damping effect. This paper examines how a tool's edge condition combines with the relief angle to affect process damping. An analytical model of cutting with chatter leads to a two-section curve describing how process damped vibration amplitude changes with surface speed for radiussed tools. The tool edge dominates the process damping effect at the lowest surface speeds, with the flank dominating at higher speeds. A similar curve is then proposed regarding tools with worn edges. Experimental data supports the notion of the two-section curve. A rule of thumb is proposed which could be useful to machine operators, regarding tool wear and process damping. The question is addressed, should a tool of a given geometry, used for a given application, be considered as sharp, radiussed or worn regarding process damping.

  8. A tool for cutting ultra thin slits in metals

    NASA Technical Reports Server (NTRS)

    Mcmahon, W.

    1972-01-01

    Tool produces slits of 0.0305 mm widths in materials up to RC 50 hardness, minimizes material waste and improves precision. Device may be used for general metal cutting and for producing simulated cracks in metal samples used in fatigue tests.

  9. Selection and Implementation of a Replacement Cutting Tool Selection Application

    SciTech Connect

    Rice, Gordon

    2008-10-06

    A new commercial cutting tool software package replaced an internally created legacy system. This report describes the issues that surfaced during the migration and installation of the commercial package and the solutions employed. The primary issues discussed are restructuring the data between two drastically different database schemas and the creation of individual component graphics.

  10. Cut-off point for the trail making test to predict unsafe driving after stroke

    PubMed Central

    Choi, Seong Youl; Lee, Jae Shin; Oh, Young Ju

    2016-01-01

    [Purpose] This study examined the cut-off point of the Trail Making Test in predicting the risk of unsafe driving in stroke patients. [Subjects and Methods] A total of 81 stroke patients with a driver’s license participated in this study. The DriveABLE Cognitive Assessment Tool, Trail Making Test-A, and Trail Making Test-B evaluations were conducted in all participants. All participants were classified into the safety or risk groups based on the DriveABLE Cognitive Assessment Tool evaluation results. The Trail Making Test results underwent a receiver operating characteristic analysis in each group. [Results] The results of the receiver operating characteristic curve analysis showed that the cut-off point for Trail Making Test-A was 32 seconds and the cut-off point for Trail Making Test-B was 79 seconds. The positive predictive values of the Trail Making Test-A and Trail Making Test-B were 98.3% and 98.3%, respectively, and the negative predictive values of the Trail Making Test-A and Trail Making Test-B were 81.0% and 73.9%, respectively. [Conclusion] The Trail Making Test is a useful tool for predicting the risk of unsafe driving in stroke patients. This tool is expected to be used more actively for screening stroke drivers with respect to their cognitive function. PMID:27512277

  11. Enhancing efficiency and quality of statistical estimation of immunogenicity assay cut points through standardization and automation.

    PubMed

    Su, Cheng; Zhou, Lei; Hu, Zheng; Weng, Winnie; Subramani, Jayanthi; Tadkod, Vineet; Hamilton, Kortney; Bautista, Ami; Wu, Yu; Chirmule, Narendra; Zhong, Zhandong Don

    2015-10-01

    Biotherapeutics can elicit immune responses, which can alter the exposure, safety, and efficacy of the therapeutics. A well-designed and robust bioanalytical method is critical for the detection and characterization of relevant anti-drug antibody (ADA) and the success of an immunogenicity study. As a fundamental criterion in immunogenicity testing, assay cut points need to be statistically established with a risk-based approach to reduce subjectivity. This manuscript describes the development of a validated, web-based, multi-tier customized assay statistical tool (CAST) for assessing cut points of ADA assays. The tool provides an intuitive web interface that allows users to import experimental data generated from a standardized experimental design, select the assay factors, run the standardized analysis algorithms, and generate tables, figures, and listings (TFL). It allows bioanalytical scientists to perform complex statistical analysis at a click of the button to produce reliable assay parameters in support of immunogenicity studies. PMID:26130368

  12. Autonomous compact cutting tools for working under special conditions

    NASA Astrophysics Data System (ADS)

    Kobrin, V. N.; Danilov, O. Iu.; Shimko, V. A.; Tsygankov, O. S.

    The paper is concerned with the problem of the maintenance and repair of complex large-scale systems in space. Particular attention is given to the design of tools intended for such operations as cutting structural elements (e.g., pipes, sections, and trusses) and making holes for various fasteners. The principal requirements for such tools, when used for maintenance in the field, far from the base, are defined. These include self-sufficiency, compact size, and either manual operation or the use of an energy accumulator or a readily available power source. Some possible tool designs and power sources are briefly reviewed.

  13. Study on machining mechanism of nanotwinned CBN cutting tool

    NASA Astrophysics Data System (ADS)

    Chen, Junyun; Jin, Tianye; Wang, Jinhu; Zhao, Qingliang; Lu, Ling

    2014-08-01

    The latest developed nanotwinned cubic boron nitride (nt-CBN) with isotropic nano-sized microstructure possesses an extremely high hardness (~100GPa Hv), very large fracture toughness (>12Mpa m1/2) and excellent high temperature stability. Thus nt-CBN is a promising tool material to realize ultra-precision cutting of hardened steel which is widely used in mold insert of optical and opto-electrical mass products. In view of its hard machinability, the machining mechanism is studied in this paper. Three feasible methods of mechanical lapping, laser machining as well as ion beam sputtering are applied to process nt-CBN. The results indicate that among the three kinds of methods, mechanical lapping not only can achieve the highest machining accuracy because of material removing at ductile mode completely, but also has satisfactory high material removal rate. Thus mechanical lapping method is appropriate to finish machining of nt-CBN cutting tool. Moreover, laser machining method can be only used in contour machining or rough machining of cutting tool as worse machined surface quality. With regard to ion beam sputtering method, the material remove rate is too low in spite of high machining accuracy. Additionally, no phase transition was found in any machining process of nt-CBN.

  14. Agile and green manufacturing and super hard coated cutting tools

    SciTech Connect

    Chi-Hung Shen

    1995-12-31

    The paper discusses the global movement towards an agile and green manufacturing environment and their impacts on high volume producers such the automotive industry. In the area of machining, two major shifts are envision (1) proliferation of highly flexible CNC single spindle machining centers to replace conventional dedicated transfer lines and (2) implementation of {open_quotes}dry{close_quotes} machining systems where there are no or minimal use of machining fluids. In order to migrate towards these goals and still remain competitive and profitable, economically viable high performance super hard coated cutting tools must be developed. Machining results with CVD diamond coated tools are presented to illustrate their current capabilities and limitations. Key areas for further research and develop of super hard coating tools will also be discussed.

  15. Insert facing tool. [manually operated cutting tool for forming studs in honeycomb material

    NASA Technical Reports Server (NTRS)

    Abernathy, W. J.; Snoddy, L. G. (Inventor)

    1974-01-01

    A manually actuated tool for facing the exposed end of an insert installed in a honeycomb panel is described. Several cutting bits are held in a round body portion that is rotated around the end of a stud to provide the cutting action. Pressure is adjusted through a spring against the body portion and the surface of the stud by a pressure nut threaded on the stud. A diagram of the components of the device is provided.

  16. Effect of cut-off points on performance of laser fluorescence for detecting occlusal caries.

    PubMed

    Braga, Mariana M; Mendes, Fausto M; Imparato, José Carlos P; Rodrigues, Célia R M D

    2007-01-01

    This in vitro study aimed to evaluate the influence of cut-off points on the performance of laser fluorescence (LF) in detecting occlusal caries in permanent and primary teeth. The use of different cut-off points influenced the performance of LF device in detection of occlusal caries in both kind of teeth, but the performance in permanent teeth suffered more influence from variation of cut-off points scales than in primary group. PMID:18274467

  17. Diamond-coated cutting tools for biomedical applications

    NASA Astrophysics Data System (ADS)

    Jackson, M. J.; Hyde, L. J.; Ahmed, W.; Sein, H.; Flaxman, R. P.

    2004-08-01

    Diamond coatings are attractive for cutting processes due to their high-hardness, low-friction coefficient; excellent wear resistance, and chemical inertness. The application of diamond coatings on cemented, tungsten carbide (WC-Co) burs has been the subject of much attention in recent years as a method to improve cutting performance and tool life. WC-Co burs containing 6% Co and 94% WC substrate, with an average grain size of 1 3 µm, were used in this study. To improve the adhesion between diamond and WC substrates, it is necessary to etch away the surface Co and prepare the surface for subsequent diamond growth. Hot filament chemical vapor deposition (HFCVD), with a modified vertical filament arrangement, has been used for the deposition of diamond films. Diamond film quality and purity has been characterized using scanning electron microscopy (SEM) and micro-Raman spectroscopy. The performance of diamond-coated WC-Co burs, uncoated WC-Co burs, and diamond-embedded (sintered) burs have been compared by drilling a series of holes into various materials such as human teeth, borosilicate glass, and acrylic teeth. Flank wear has been used to assess the wear rates of the burs when machining biomedical materials such as those just described.

  18. Small-size measuring gauges for metal cutting machine tools

    NASA Astrophysics Data System (ADS)

    Levin, B. M.; Lyapkov, V. N.; Myasnikov, Y. A.; Kirsanova, L. N.

    1984-02-01

    Recently two new models of suspension type optical measuring gauges have been developed with a 0.01 mm scale division, for measuring displacements of movable parts in metal cutting machine tools. The first one is the IG-98 consisting of an STs-80 incandescent lamp, a light filter, two reference rulers, two objectives, a light splitter cube, four plane mirrors, two condenser lenses, a graduated circle and a magnifying glass. The second one is the IG-119 consisting of an STs-61 incandescent lamp, a light filter, a rectangular prism with cover, two reference rulers, two objectives, a light splitter cube, one mirror, one condenser lens, a cylindrical shield and a magnifying glass. A complete accuracy analysis of both instruments indicates that two out of the seven principal error components are negligible, namely the angular error of the null adjustment guides and the temperature error referred to the plane of one of the reference rulers.

  19. Large cutting tools in the Danjiangkou Reservoir Region, central China.

    PubMed

    Kuman, Kathleen; Li, Chaorong; Li, Hao

    2014-11-01

    Handaxe-bearing sites in China are currently known to occur in a number of alluvial basins, the best known being Dingcun, Bose and Luonan. Bose in the south and Luonan in central China on the northern margin of the Qinling Mountains are most familiar to English-speaking researchers. Here we document the Danjiangkou Reservoir Region (DRR) as another major area for large cutting tools (LCTs), located in central China on the southeastern edge of the Qinling Mountains. Large cutting tools are preserved in three terraces of the Han and Dan Rivers in Hubei and Henan Provinces, with dates from ca. 0.8 Ma (millions of years ago) (Terrace 4) to the first half of the Middle Pleistocene (Terrace 3), and possibly to the Late Pleistocene (Terrace 2). This paper reports on LCTs discovered in Terraces 3 and 2, with a majority from the older terrace (and one specimen from Terrace 4). Regional environments during the Middle Pleistocene were relatively warm, humid and stable. Despite the poor quality of raw materials (predominantly quartz phyllite and trachyte for the LCTs), good examples of both handaxes and cleavers are present, plus two types of picks. The LCT technology is compared and contrasted with other Asian industries and with the Acheulean. Overall the DRR LCTs show both technological and morphological similarities with Acheulean LCTs, with some differences that are mainly attributed to raw material properties, subsistence ecology, and 'cultural drift.' The DRR LCTs expand the range of morphological variability of the East Asian material and highlight the need for greater reliance on technological analysis and raw material evaluation for best comparison of Chinese assemblages with the Acheulean tradition. PMID:25223718

  20. Cutting effectiveness of diamond points on commercial core composite resins and cements.

    PubMed

    Miyawaki, H; Taira, M; Yamaki, M

    1996-06-01

    In dental clinics, composite resin and cement cores are routinely cut and polished during abutment tooth preparation. To identify their characteristics during cutting, weight-load cutting tests were performed on eight commercial core composites and two cements, using diamond points driven by an air-turbine handpiece. It became evident that the cutting effectiveness of the diamond points on nine workpieces exceeded that on natural tooth dentine, while that on one composite containing Si3,N4 filler was analogous to that on dentine. With continued use, the cutting effectiveness of the diamond point on all workpieces gradually declined. SEM observations revealed that diamond particles of the diamond point wore out with repeated use. It is clinically advised to select the core material with material characteristics during cutting and mechanical strength similar to those of dentin. PMID:8809696

  1. Cryogenic turning of the Ti-6Al-4V alloy with modified cutting tool inserts

    NASA Astrophysics Data System (ADS)

    Dhananchezian, M.; Pradeep Kumar, M.

    2011-01-01

    Productivity in the machining of titanium alloys is adversely affected by rapid tool wear as a consequence of high cutting zone temperature. Conventional cutting fluids are ineffective in controlling the cutting temperature in the cutting zone. In this research work, an attempt has been made to investigate the effect of liquid nitrogen when it is applied to the rake surface, and the main and auxiliary flank surfaces through holes made in the cutting tool insert during the turning of the Ti-6Al-4V alloy. The cryogenic results of the cutting temperature, cutting forces, surface roughness and tool wear of the modified cutting tool insert have been compared with those of wet machining. It has been observed that in the cryogenic cooling method, the cutting temperature was reduced by 61-66% and the surface roughness was reduced to a maximum of 36% over wet machining. The cutting force was decreased by 35-42% and the flank wear was reduced by 27-39% in cryogenic cooling over that of wet machining. Cryogenic cooling enabled a substantial reduction in the geometry of tool wear through the control of the tool wear mechanisms. The application of liquid nitrogen to the heat generation zones through holes made in the cutting tool insert was considered to be more effective over conventional machining.

  2. Determining BMI cut points based on excess percent body fat in US children and adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current cut points for overweight were derived statistically from BMI distribution. The study aimed at determining age-, gender-, and ethnic-specific BMI cut points based on excess body fat in US children and adolescents aged 8-17 years, who participated in the National Health and Nutrition Examinat...

  3. Monitoring cutting tool operation and condition with a magnetoelastic rate of change of torque sensor

    SciTech Connect

    Garshelis, Ivan J.; Kari, Ryan J.; Tollens, Stijn P. L.; Cuseo, James M.

    2008-04-01

    Application of a magnetoelastic rate of change of torque sensor to monitor the condition of milling cutters and operating parameters is described. Cutting tools naturally degrade with use by wear, chipping, or fracture, and the efficiency and quality of the product are highly dependent on the tool condition. The theoretical analysis is compared to experimental data in detecting changes in torque during each cutting event, and the rate of change of torque signal is investigated for a variety of cutting tool conditions.

  4. Comparison of Mechanical Properties and Calculation of Cutting Force Between Uncoated Tungsten Carbide & ti Coated Tip Tungsten Carbide with the Help of Lathe Tool Dynamometer

    NASA Astrophysics Data System (ADS)

    Mehra, Deepak; Rakhecha, Khushwant

    The keyword for manufacturers of cutting tools and coatings for cutting tools is productivity: a 30%; reduction of tool costs, or a 50%; increase in tool lifetime results only in a 1%; reduction of manufacturing costs. But an increase in cutting data by 20%; reduces manufacturing costs by 15%;. In order to achieve higher productivity different approaches - High Performance Cutting (HPC) and High Speed Cutting (HSC) can be chosen. The performance of Carbide tools was studied to investigate the tool life and wear behavior at various machining parameters. This study presents tool wear characterization of carbide cutting tool inserts coated with titanium nitride (TiN) on a single point turning operation on copper, aluminum. A set of experiments with conditions of cutting speed, depth of cut and feed rate were performed on a lathe machine. Force analysis is done on Lathe Tool Dynamometer. From the result, cutting speed was found to be the main factor to have significant effect on surface roughness. At the end of this study, optimization was made by suggesting the most suitable sets of parameter settings to produce minimum surface roughness. Suggestion on parameter settings to obtain minimum surface roughness made.

  5. Tool holder for preparation and inspection of a radiused edge cutting tool

    DOEpatents

    Asmanes, Charles

    1979-01-01

    A tool holding fixture is provided for removably holding a radiused edge cutting tool in a tool edge lapping apparatus. The fixture allows the operator to preset the lapping radius and angle before the tool holder is placed in the fixture and the holder may be removed from the lapping apparatus to inspect the tool and simply replaced in the fixture to continue lapping in accordance with a precise alignment without realignment of the tool relative to the lap. The tool holder includes a pair of self aligning bearings in the form of precision formed steel balls connected together by a rigid shaft. The tool is held by an arm extending from the shaft and the balls set in fixed position bearing cups and the holder is oscillated back and forth about a fixed axis of rotation to lap the tool radius by means of a reversibly driven belt-pulley arrangement coupled to the shaft between the bearings. To temporarily remove the holder, the drive belt is slipped over the rearward end of the holder and the holder is lifted out of the bearing cups.

  6. Modelling of cutting tool - soil interaction - part I: contact behaviour

    NASA Astrophysics Data System (ADS)

    Nardin, A.; Zavarise, G.; Schrefler, B. A.

    The unknown interaction of the cutting tools with geological settings represents an interesting problem for the excavation machinery industry. To simplify the non-linear aspects involved in the numerical analysis of such phenomena a strategy for an accurate soil modelling has to be defined. A possible approach is the discrete one, by considering the soil as an assembly of rigid spheres. In this work this strategy is adopted. The basic idea is to concentrate at the contact level between the spheres the real mechanical behaviour of the soil. For this purpose suitable contact models have been developed, where specific elasto-plastic laws have been implemented in the node-to-segment contact formulation. The framework for the plastic behaviour consists of a failure criterion, a one-dimensional, rate-independent elasto-plastic flow rule for the normal and the tangential force and a non-linear yield criterion. The final aim of this paper is to develop mechanical models to study the behaviour of stiff soils and rocks under different loading conditions.

  7. High power laser downhole cutting tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  8. Communication research between working capacity of hard- alloy cutting tools and fractal dimension of their wear

    NASA Astrophysics Data System (ADS)

    Arefiev, K.; Nesterenko, V.; Daneykina, N.

    2016-06-01

    The results of communication research between the wear resistance of the K applicability hard-alloy cutting tools and the fractal dimension of the wear surface, which is formed on a back side of the cutting edge when processing the materials showing high adhesive activity are presented in the paper. It has been established that the wear resistance of tested cutting tools samples increases according to a fractal dimension increase of their wear surface.

  9. Design of an instrumented smart cutting tool and its implementation and application perspectives

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Cheng, Kai; Chen, Xun; Minton, Timothy; Rakowski, Richard

    2014-03-01

    This paper presents an innovative design of a smart cutting tool, using two surface acoustic wave (SAW) strain sensors mounted onto the top and the side surface of the tool shank respectively, and its implementation and application perspectives. This surface acoustic wave-based smart cutting tool is capable of measuring the cutting force and the feed force in a real machining environment, after a calibration process under known cutting conditions. A hybrid dissimilar workpiece is then machined using the SAW-based smart cutting tool. The hybrid dissimilar material is made of two different materials, NiCu alloy (Monel) and steel, welded together to form a single bar; this can be used to simulate an abrupt change in material properties. The property transition zone is successfully detected by the tool; the sensor feedback can then be used to initiate a change in the machining parameters to compensate for the altered material properties.

  10. Producing Fe-W-Co-Cr-C Alloy Cutting Tool Material Through Powder Metallurgy Route

    NASA Astrophysics Data System (ADS)

    Datta Banik, Bibhas; Dutta, Debasish; Ray, Siddhartha

    2016-06-01

    High speed steel tools can withstand high impact forces as they are tough in nature. But they cannot retain their hardness at elevated temperature i.e. their hot hardness is low. Therefore permissible cutting speed is low and tools wear out easily. Use of lubricants is essential for HSS cutting tools. On the other hand cemented carbide tools can withstand greater compressive force, but due to lower toughness the tool can break easily. Moreover the cost of the tool is comparatively high. To achieve a better machining economy, Fe-W-Co-Cr-C alloys are being used nowadays. Their toughness is as good as HSS tools and hardness is very near to carbide tools. Even, at moderate cutting speeds they can be safely used in old machines having vibration. Moreover it is much cheaper than carbide tools. This paper highlights the Manufacturing Technology of the alloy and studies the comparative tribological properties of the alloy and tungsten mono carbide.

  11. Effect of Flexural Rigidity of Tool on Machining Accuracy during Microgrooving by Ultrasonic Vibration Cutting Method

    NASA Astrophysics Data System (ADS)

    Furusawa, Toshiaki

    2010-12-01

    It is necessary to form fine holes and grooves by machining in the manufacture of equipment in the medical or information field and the establishment of such a machining technology is required. In micromachining, the use of the ultrasonic vibration cutting method is expected and examined. In this study, I experimentally form microgrooves in stainless steel SUS304 by the ultrasonic vibration cutting method and examine the effects of the shape and material of the tool on the machining accuracy. As a result, the following are clarified. The evaluation of the machining accuracy of the straightness of the finished surface revealed that there is an optimal rake angle of the tools related to the increase in cutting resistance as a result of increases in work hardening and the cutting area. The straightness is improved by using a tool with low flexural rigidity. In particular, Young's modulus more significantly affects the cutting accuracy than the shape of the tool.

  12. A Distance-Weighted Graph-Cut Method for the Segmentation of Laser Point Clouds

    NASA Astrophysics Data System (ADS)

    Dutta, A.; Engels, J.; Hahn, M.

    2014-08-01

    Normalized Cut according to (Shi and Malik 2000) is a well-established divisive image segmentation method. Here we use Normalized Cut for the segmentation of laser point clouds in urban areas. In particular we propose an edge weight measure which takes local plane parameters, RGB values and eigenvalues of the covariance matrices of the local point distribution into account. Due to its target function, Normalized Cut favours cuts with "small cut lines/surfaces", which appears to be a drawback for our application. We therefore modify the target function, weighting the similarity measures with distant-depending weights. We call the induced minimization problem "Distance-weighted Cut" (DWCut). The new target function leads to a slightly more complicated generalized eigenvalue problem than in case of the Normalized Cut; on the other hand, the new target function is easier to interpret and avoids the just-mentioned drawback. DWCut can be beneficially combined with an aggregation in order to reduce the computational effort and to avoid shortcomings due to insufficient plane parameters. Finally we present examples for the successful application of the Distance-weighted Cut principle. The method was implemented as a plugin into the free and open source geographic information system SAGA; for preprocessing steps the proprietary SAGA-based LiDAR software LIS was applied.

  13. Verifying Nd-Tool Quality Using Plunge Cuts And Micro-Interferometer

    NASA Astrophysics Data System (ADS)

    Mullner, Dieter

    1986-11-01

    In micromachining of aspherical surfaces the diamond tools are used in a zone extending over a certain segment. This zone is minimized in the spherical generator type machine, but it must be found and located by knowing edge quality over the entire length. Our method of verifying edge sharpness over the entire tool radius as well as the circularity (form) consists in viewing with a micro-interferometer a plunge cut trace produced in the real tool-workpiece configuration. This allows to set a partially defective tool for optimum machining conditions. One can also set for best cutting depth, because certain tool damages on the rear phase become effective only with deeper cuts. This will be illustrated. The micro-interferometer plunge cut inspection allows to detect material vibration, chatter and crossflow of material.

  14. Bilingual Skills Training Program. Meat Cutting. Module 2.0: Job Classifications, Tools, Sanitation & Safety.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on job classification, tools, sanitation, and safety is the second of three (CE 028 291-293) in the meat cutting course of a bilingual skills training program. The course is designed to furnish theoretical and laboratory experience in the cutting of beef, pork, poultry, lamb, and mutton. Module objectives are for students to develop…

  15. Detection of fallen trees in ALS point clouds by learning the Normalized Cut similarity function from simulated samples

    NASA Astrophysics Data System (ADS)

    Polewski, P.; Yao, W.; Heurich, M.; Krzystek, P.; Stilla, U.

    2014-08-01

    Fallen trees participate in several important forest processes, which motivates the need for information about their spatial distribution in forest ecosystems. Several studies have shown that airborne LiDAR is a valuable tool for obtaining such information. In this paper, we propose an integrated method of detecting fallen trees from ALS point clouds based on merging small segments into entire fallen stems via the Normalized Cut algorithm. A new approach to specifying the segment similarity function for the clustering algorithm is introduced, where the attribute weights are learned from labeled data instead of being determined manually. We notice the relationship between Normalized Cut's similarity function and a class of regression models, which leads us to the idea of approximating the task of learning the similarity function with the simpler task of learning a classifier. Moreover, we set up a virtual fallen tree generation scheme to simulate complex forest scenarios with multiple overlapping fallen stems. The classifier trained on this simulated data yields a similarity function for Normalized Cut. Tests on two sample plots from the Bavarian Forest National Park with manually labeled reference data show that the trained function leads to high-quality segmentations. Our results indicate that the proposed data-driven approach can be a successful alternative to time consuming trial-and-error or grid search methods of finding good feature weights for graph cut algorithms. Also, the methodology can be generalized to other applications of graph cut clustering in remote sensing.

  16. Statistical approaches for the determination of cut points in anti-drug antibody bioassays.

    PubMed

    Schaarschmidt, Frank; Hofmann, Matthias; Jaki, Thomas; Grün, Bettina; Hothorn, Ludwig A

    2015-03-01

    Cut points in immunogenicity assays are used to classify future specimens into anti-drug antibody (ADA) positive or negative. To determine a cut point during pre-study validation, drug-naive specimens are often analyzed on multiple microtiter plates taking sources of future variability into account, such as runs, days, analysts, gender, drug-spiked and the biological variability of un-spiked specimens themselves. Five phenomena may complicate the statistical cut point estimation: i) drug-naive specimens may contain already ADA-positives or lead to signals that erroneously appear to be ADA-positive, ii) mean differences between plates may remain after normalization of observations by negative control means, iii) experimental designs may contain several factors in a crossed or hierarchical structure, iv) low sample sizes in such complex designs lead to low power for pre-tests on distribution, outliers and variance structure, and v) the choice between normal and log-normal distribution has a serious impact on the cut point. We discuss statistical approaches to account for these complex data: i) mixture models, which can be used to analyze sets of specimens containing an unknown, possibly larger proportion of ADA-positive specimens, ii) random effects models, followed by the estimation of prediction intervals, which provide cut points while accounting for several factors, and iii) diagnostic plots, which allow the post hoc assessment of model assumptions. All methods discussed are available in the corresponding R add-on package mixADA. PMID:25733352

  17. View of a stone age adze cutting tool floating freely in the flight deck.

    NASA Technical Reports Server (NTRS)

    1992-01-01

    View of a stone age adze cutting tool floating freely in the forward flight deck and framed by the forward and side windows. On the Earth below, the big island of Hawaii can be seen through the window.

  18. [Present-day metal-cutting tools and working conditions].

    PubMed

    Kondratiuk, V P

    1990-01-01

    Polyfunctional machine-tools of a processing centre type are characterized by a set of hygienic advantages as compared to universal machine-tools. But low degree of mechanization and automation of some auxiliary processes, and constructional defects which decrease the ergonomic characteristics of the tools, involve labour intensity in multi-machine processing. The article specifies techniques of allowable noise level assessment, and proposes hygienic recommendations, some of which have been introduced into practice. PMID:2328919

  19. Modelling and Optimization of Technological Process for Magnetron Synthesis of Altin Nanocomposite Films on Cutting Tools

    NASA Astrophysics Data System (ADS)

    Kozhina, T. D.

    2016-04-01

    The paper highlights the results of the research on developing the mechanism to model the technological process for magnetron synthesis of nanocomposite films on cutting tools, which provides their specified physical and mechanical characteristics by controlling pulsed plasma parameters. The paper presents optimal conditions for AlTiN coating deposition on cutting tools according to the ion energy of sputtered atoms in order to provide their specified physical and mechanical characteristics.

  20. A Calibration Protocol for Population-Specific Accelerometer Cut-Points in Children

    PubMed Central

    Mackintosh, Kelly A.; Fairclough, Stuart J.; Stratton, Gareth; Ridgers, Nicola D.

    2012-01-01

    Purpose To test a field-based protocol using intermittent activities representative of children's physical activity behaviours, to generate behaviourally valid, population-specific accelerometer cut-points for sedentary behaviour, moderate, and vigorous physical activity. Methods Twenty-eight children (46% boys) aged 10–11 years wore a hip-mounted uniaxial GT1M ActiGraph and engaged in 6 activities representative of children's play. A validated direct observation protocol was used as the criterion measure of physical activity. Receiver Operating Characteristics (ROC) curve analyses were conducted with four semi-structured activities to determine the accelerometer cut-points. To examine classification differences, cut-points were cross-validated with free-play and DVD viewing activities. Results Cut-points of ≤372, >2160 and >4806 counts•min−1 representing sedentary, moderate and vigorous intensity thresholds, respectively, provided the optimal balance between the related needs for sensitivity (accurately detecting activity) and specificity (limiting misclassification of the activity). Cross-validation data demonstrated that these values yielded the best overall kappa scores (0.97; 0.71; 0.62), and a high classification agreement (98.6%; 89.0%; 87.2%), respectively. Specificity values of 96–97% showed that the developed cut-points accurately detected physical activity, and sensitivity values (89–99%) indicated that minutes of activity were seldom incorrectly classified as inactivity. Conclusion The development of an inexpensive and replicable field-based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve the classification of physical activity levels in children, which could enhance subsequent intervention and observational studies. PMID:22590635

  1. Cutting tool performance characteristics in the machining of a nickel aluminide intermetallic compound

    SciTech Connect

    Chatterjee, S.; Srivatsan, T.S.; Giusti, P.

    1994-05-01

    Ductile nickel aluminide, Ni{sub 3}Al, containing traces of boron, is an intermetallic compound with high strength, making it a promising structural material for elevated, ambient and cryogenic temperature applications. In order to be able to use alloys, they must be capable of being fabricated by machining. The machinability of a cast nickel aluminide, Ni{sub 3}Al, alloy containing boron was studied by conventional machining using the lathe. Three different cutting tool inserts and two types of coolants, namely kerosene oil mist and soluble oil, were chosen. The machining performance of the cutting tool insert and the influence of coolant type were established through measurements of volume of material removed and tool wear. The tool wear analysis was made using microscopic examination of the cutting tool insert in order to elucidate information of the influence of machining parameters and choice of coolant on performance capability of the insert. The overall machinability performance of these materials is rationalized.

  2. Laser Processing of Coarse Grain Polycrystalline Diamond (PCD) Cutting Tool Inserts using Picosecond Laser Pulses

    NASA Astrophysics Data System (ADS)

    Dold, C.; Henerichs, M.; Gilgen, P.; Wegener, K.

    Manufacturing of cutting edges in PCD cutting tool inserts (CTI) using picosecond pulsewidth laser sources is presented. Cutting edge radii of redge = 5 to 6 μm are achieved. Validation experiments are carried out on a turning lathe using lasered and ground CTI on machining carbon fibre reinforced plastics (CFRP) which is mainly used for aircraft structures. Experiments are done on fine and coarse grain PCD structures (average grain sizes are 2-4 μm and 25 μm resepectively) which are not economical in the latter case if manufactured conventionally, e.g. using grinding processes. Wear resistance, tool lifetime and process forces can be improved if laser processed coarse grain cutting tools are employed.

  3. Accelerometer Cut Points for Physical Activity Assessment of Older Adults with Parkinson’s Disease

    PubMed Central

    Nero, Håkan; Benka Wallén, Martin; Franzén, Erika; Ståhle, Agneta; Hagströmer, Maria

    2015-01-01

    Objective To define accelerometer cut points for different walking speeds in older adults with mild to moderate Parkinson’s disease. Method A volunteer sample of 30 older adults (mean age 73; SD 5.4 years) with mild to moderate Parkinson’s disease walked at self-defined brisk, normal, and slow speeds for three minutes in a circular indoor hallway, each wearing an accelerometer around the waist. Walking speed was calculated and used as a reference measure. Through ROC analysis, accelerometer cut points for different levels of walking speed in counts per 15 seconds were generated, and a leave-one-out cross-validation was performed followed by a quadratic weighted Cohen’s Kappa, to test the level of agreement between true and cut point–predicted walking speeds. Results Optimal cut points for walking speeds ≤ 1.0 m/s were ≤ 328 and ≤ 470 counts/15 sec; for speeds > 1.3 m/s, they were ≥ 730 and ≥ 851 counts/15 sec for the vertical axis and vector magnitude, respectively. Sensitivity and specificity were 61%–100% for the developed cut points. The quadratic weighted Kappa showed substantial agreement: κ = 0.79 (95% CI 0.70–0.89) and κ = 0.69 (95% CI 0.56–0.82) for the vertical axis and the vector magnitude, respectively. Conclusions This study provides accelerometer cut points based on walking speed for physical-activity measurement in older adults with Parkinson’s disease for evaluation of interventions and for investigating links between physical activity and health. PMID:26332765

  4. Reliability estimation for cutting tools based on logistic regression model using vibration signals

    NASA Astrophysics Data System (ADS)

    Chen, Baojia; Chen, Xuefeng; Li, Bing; He, Zhengjia; Cao, Hongrui; Cai, Gaigai

    2011-10-01

    As an important part of CNC machine, the reliability of cutting tools influences the whole manufacturing effectiveness and stability of equipment. The present study proposes a novel reliability estimation approach to the cutting tools based on logistic regression model by using vibration signals. The operation condition information of the CNC machine is incorporated into reliability analysis to reflect the product time-varying characteristics. The proposed approach is superior to other degradation estimation methods in that it does not necessitate any assumption about degradation paths and probability density functions of condition parameters. The three steps of new reliability estimation approach for cutting tools are as follows. First, on-line vibration signals of cutting tools are measured during the manufacturing process. Second, wavelet packet (WP) transform is employed to decompose the original signals and correlation analysis is employed to find out the feature frequency bands which indicate tool wear. Third, correlation analysis is also used to select the salient feature parameters which are composed of feature band energy, energy entropy and time-domain features. Finally, reliability estimation is carried out based on logistic regression model. The approach has been validated on a NC lathe. Under different failure threshold, the reliability and failure time of the cutting tools are all estimated accurately. The positive results show the plausibility and effectiveness of the proposed approach, which can facilitate machine performance and reliability estimation.

  5. Metal Cutting Theory and Friction Stir Welding Tool Design

    NASA Technical Reports Server (NTRS)

    Payton, Lewis N.

    2003-01-01

    Friction Stir Welding (FSW) is a relatively new industrial process that was invented at The Weld Institute (TWI, United Kingdom) and patented in 1992 under research funded by in part by the National Aeronautics and Space Administration (NASA). Often quoted advantages of the process include good strength and ductility along with minimization of residual stress and distortion. Less well advertised are the beneficial effects of this solid state welding process in the field of occupational and environmental safety. It produces superior weld products in difficult to weld materials without producing any toxic fumes or solid waste that must be controlled as hazardous waste. In fact, it reduces noise pollution in the workspace as well. In the early days of FSW, most welding was performed on modified machine tools, in particular on milling machines with modified milling cutters. In spite of the obvious milling heritage of the process, the techniques and lessons learned from almost 250 years of successful metalworking with milling machines have not been applied in the field of modern Friction Stir Welding. The goal of the current research was to study currently successful FSW tools and parameterize the process in such a way that the design of new tools for new materials could be accelerated. Along the way, several successful new tooling designs were developed for current issues at the Marshall Space Flight Center with accompanying patent disclosures

  6. Effects of cyclone diameter on performance of 1D3D cyclones: Cut point and slope

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclones are a commonly used air pollution abatement device for separating particulate matter (PM) from air streams in industrial processes. Several mathematical models have been proposed to predict the cut point of cyclones as cyclone diameter varies. The objective of this research was to determine...

  7. Wall sticking of high water-cut crude oil transported at temperatures below the gel point

    NASA Astrophysics Data System (ADS)

    Zheng, Haimin; Huang, Qiyu; Wang, Changhui

    2015-12-01

    Some high water-cut crude oils can flow in the temperature below the oil gel point, while oil particles may adhere to the pipe wall as paste; this process is known as ‘wall sticking’. This can cause partial or even total blocking of the transportation pipe. Several experiments using a laboratory flow loop were conducted to study the wall sticking characteristics of high water-cut crude oils. The experimental results indicated that the predominant influencing factors of wall sticking included shear stress, water-cut and differences between gel point and wall temperature. The wall sticking rate and occurrence temperature decrease with the increase of water-cut and shear stress. The criterion for the wall sticking occurrence temperature (WSOT), and the regression formula of the wall sticking thickness for high water-cut crude oil were then established. Typical case studies indicated that the prediction results obtained from the WSOT criterion and the wall sticking thickness regression formula were in accordance with the measured values. The wall sticking rate and WSOT vary widely under different conditions and it is necessary to consider its non-uniformity in production.

  8. Information Technology: A Tool to Cut Health Care Costs

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi; Maly, K. J.; Overstreet, C. M.; Foudriat, E. C.

    1996-01-01

    Old Dominion University embarked on a project to see how current computer technology could be applied to reduce the cost and or to improve the efficiency of health care services. We designed and built a prototype for an integrated medical record system (MRS). The MRS is written in Tool control language/Tool kit (Tcl/Tk). While the initial version of the prototype had patient information hard coded into the system, later versions used an INGRES database for storing patient information. Currently, we have proposed an object-oriented model for implementing MRS. These projects involve developing information systems for physicians and medical researchers to enhance their ability for improved treatment at reduced costs. The move to computerized patient records is well underway, several standards exist for laboratory records, and several groups are working on standards for other portions of the patient record.

  9. Effects of cutting parameters on tool insert wear in end milling of titanium alloy Ti6Al4V

    NASA Astrophysics Data System (ADS)

    Luo, Ming; Wang, Jing; Wu, Baohai; Zhang, Dinghua

    2016-06-01

    Titanium alloy is a kind of typical hard-to-cut material due to its low thermal conductivity and high strength at elevated temperatures, this contributes to the fast tool wear in the milling of titanium alloys. The influence of cutting conditions on tool wear has been focused on the turning process, and their influence on tool wear in milling process as well as the influence of tool wear on cutting force coefficients has not been investigated comprehensively. To fully understand the tool wear behavior in milling process with inserts, the influence of cutting parameters on tool wear in the milling of titanium alloys Ti6Al4V by using indexable cutters is investigated. The tool wear rate and trends under different feed per tooth, cutting speed, axial depth of cut and radial depth of cut are analyzed. The results show that the feed rate per tooth and the radial depth of cut have a large influence on tool wear in milling Ti6Al4V with coated insert. To reduce tool wear, cutting parameters for coated inserts under experimental cutting conditions are set as: feed rate per tooth less than 0.07 mm, radial depth of cut less than 1.0 mm, and cutting speed sets between 60 and 150 m/min. Investigation on the relationship between tool wear and cutting force coefficients shows that tangential edge constant increases with tool wear and cutter edge chipping can lead to a great variety of tangential cutting force coefficient. The proposed research provides the basic data for evaluating the machinability of milling Ti6Al4V alloy with coated inserts, and the recommend cutting parameters can be immediately applied in practical production.

  10. Operation reliability assessment for cutting tools by applying a proportional covariate model to condition monitoring information.

    PubMed

    Cai, Gaigai; Chen, Xuefeng; Li, Bing; Chen, Baojia; He, Zhengjia

    2012-01-01

    The reliability of cutting tools is critical to machining precision and production efficiency. The conventional statistic-based reliability assessment method aims at providing a general and overall estimation of reliability for a large population of identical units under given and fixed conditions. However, it has limited effectiveness in depicting the operational characteristics of a cutting tool. To overcome this limitation, this paper proposes an approach to assess the operation reliability of cutting tools. A proportional covariate model is introduced to construct the relationship between operation reliability and condition monitoring information. The wavelet packet transform and an improved distance evaluation technique are used to extract sensitive features from vibration signals, and a covariate function is constructed based on the proportional covariate model. Ultimately, the failure rate function of the cutting tool being assessed is calculated using the baseline covariate function obtained from a small sample of historical data. Experimental results and a comparative study show that the proposed method is effective for assessing the operation reliability of cutting tools. PMID:23201980

  11. Modelling and Development of a High Performance Milling Process with Monolithic Cutting Tools

    NASA Astrophysics Data System (ADS)

    Ozturk, E.; Taylor, C. M.; Turner, S.; Devey, M.

    2011-05-01

    Critical aerospace components usually require difficult to machine workpiece materials like nickel based alloys. Moreover; there is a pressing need to maximize the productivity of machining operations. This need can be satisfied by selection of higher feed velocity, axial and radial depths. But there may be several problems during machining in this case. Due to high cutting speeds in high performance machining, the tool life may be unacceptably low. If magnitudes of cutting forces are high, out of tolerance static form errors may result; moreover in the extreme cases, the cutting tool may break apart. Forced vibrations may deteriorate the surface quality. Chatter vibrations may develop if the selected parameters result in instability. In this study, in order to deal with the tool life issue, several experimental cuts are made with different tool geometries, and the best combination in terms of tool life is selected. A force model is developed and the results of the force model are verified by experimental results. The force model is used in predicting the effect of process parameters on cutting forces. In order to account for the other concerns such as static form errors, forced and chatter vibrations, additional process models are currently under development.

  12. Operation Reliability Assessment for Cutting Tools by Applying a Proportional Covariate Model to Condition Monitoring Information

    PubMed Central

    Cai, Gaigai; Chen, Xuefeng; Li, Bing; Chen, Baojia; He, Zhengjia

    2012-01-01

    The reliability of cutting tools is critical to machining precision and production efficiency. The conventional statistic-based reliability assessment method aims at providing a general and overall estimation of reliability for a large population of identical units under given and fixed conditions. However, it has limited effectiveness in depicting the operational characteristics of a cutting tool. To overcome this limitation, this paper proposes an approach to assess the operation reliability of cutting tools. A proportional covariate model is introduced to construct the relationship between operation reliability and condition monitoring information. The wavelet packet transform and an improved distance evaluation technique are used to extract sensitive features from vibration signals, and a covariate function is constructed based on the proportional covariate model. Ultimately, the failure rate function of the cutting tool being assessed is calculated using the baseline covariate function obtained from a small sample of historical data. Experimental results and a comparative study show that the proposed method is effective for assessing the operation reliability of cutting tools. PMID:23201980

  13. Modelling and Development of a High Performance Milling Process with Monolithic Cutting Tools

    SciTech Connect

    Ozturk, E.; Taylor, C. M.; Turner, S.; Devey, M.

    2011-05-04

    Critical aerospace components usually require difficult to machine workpiece materials like nickel based alloys. Moreover; there is a pressing need to maximize the productivity of machining operations. This need can be satisfied by selection of higher feed velocity, axial and radial depths. But there may be several problems during machining in this case. Due to high cutting speeds in high performance machining, the tool life may be unacceptably low. If magnitudes of cutting forces are high, out of tolerance static form errors may result; moreover in the extreme cases, the cutting tool may break apart. Forced vibrations may deteriorate the surface quality. Chatter vibrations may develop if the selected parameters result in instability. In this study, in order to deal with the tool life issue, several experimental cuts are made with different tool geometries, and the best combination in terms of tool life is selected. A force model is developed and the results of the force model are verified by experimental results. The force model is used in predicting the effect of process parameters on cutting forces. In order to account for the other concerns such as static form errors, forced and chatter vibrations, additional process models are currently under development.

  14. The guillotine knife: a novel tool for safe endoscopic cutting of intracranial membranes.

    PubMed

    El Damaty, Ahmed; Manwaring, Jotham C; Schroeder, Henry W S

    2014-09-01

    This article describes a new endoscopic cutting tool that acts like a guillotine. It enables safe cutting of membranes overlying neurovascular structures because the footplate protects these structures from inadvertent injury. The footplate is introduced under the membrane, elevating it slightly, and then the membrane is cut while pushing the blade down into the footplate. The guillotine knife has been used in various endoscopic procedures such as septostomies, arachnoid cyst fenestrations, colloid cysts resections, and fenestrations of other intraventricular membranes. The authors think that the guillotine knife is a useful addition to the neuroendoscopic armamentarium. PMID:24926646

  15. Effect of Plasma Nitriding on the Performance of WC-Co Cutting Tools

    NASA Astrophysics Data System (ADS)

    Hamzaoglu, Ebru; Yilmaz, Safak; Gulmez, Turgut

    2011-04-01

    This paper presents the effect of nitriding process parameters on the cutting performance of WC-Co tools. The cutting performance was measured by CNC machining of GG25 cast iron parts. The hardness and phase composition of nitrided layer were determined for different plasma nitriding temperatures and times. The hardness of the nitrided layer increased at all plasma nitrided conditions investigated. However, the machining performance of the cutting inserts varied in the range between a 60% increase and a 40% decrease after plasma nitriding. The maximum number of machined parts was seen when the insert was nitrided at 600 °C-4 h and at 500 °C-4 h.

  16. Kinect, a Novel Cutting Edge Tool in Pavement Data Collection

    NASA Astrophysics Data System (ADS)

    Mahmoudzadeh, A.; Firoozi Yeganeh, S.; Golroo, A.

    2015-12-01

    Pavement roughness and surface distress detection is of interest of decision makers due to vehicle safety, user satisfaction, and cost saving. Data collection, as a core of pavement management systems, is required for these detections. There are two major types of data collection: traditional/manual data collection and automated/semi-automated data collection. This paper study different non-destructive tools in detecting cracks and potholes. For this purpose, automated data collection tools, which have been utilized recently are discussed and their applications are criticized. The main issue is the significant amount of money as a capital investment needed to buy the vehicle. The main scope of this paper is to study the approach and related tools that not only are cost-effective but also precise and accurate. The new sensor called Kinect has all of these specifications. It can capture both RGB images and depth which are of significant use in measuring cracks and potholes. This sensor is able to take image of surfaces with adequate resolution to detect cracks along with measurement of distance between sensor and obstacles in front of it which results in depth of defects. This technology has been very recently studied by few researchers in different fields of studies such as project management, biomedical engineering, etc. Pavement management has not paid enough attention to use of Kinect in monitoring and detecting distresses. This paper is aimed at providing a thorough literature review on usage of Kinect in pavement management and finally proposing the best approach which is cost-effective and precise.

  17. PIXE as a characterization technique in the cutting tool industry

    NASA Astrophysics Data System (ADS)

    Freemantle, C. S.; Sacks, N.; Topic, M.; Pineda-Vargas, C. A.

    2014-01-01

    Two WC-Co powders have been analyzed using micro-PIXE to identify elemental concentration and distribution. A powder recycled primarily from used mining components and a powder produced exclusively from fresh raw materials was studied. Elemental mapping of major elements as well as impurities, within powder granule cross sections, was performed. Contaminants (e.g. Fe and Ni) from manufacturing processes, as well as trace impurities (e.g. Cr, Cl, Ca and S) from recycling were detected, quantified and compared. The extent of increased concentrations of impurities resulting from recycling were observed, demonstrating the potential for PIXE as a characterization tool for detecting trace elements in cemented carbides, allowing for future improvements in the manufacturing and recycling processes.

  18. Experimental Choice of Suitable Cutting Tool for Machining of Plastic

    NASA Astrophysics Data System (ADS)

    Sokova, Dagmar; Cep, Robert; Cepova, Lenka; Kocifajova, Simona

    2014-12-01

    In today's competitive times overall development of the technology is moving somewhere further, including automotive industry, which went toward relieving material. One of the many materials which are applied in the automotive industry, are polymers. The aim of the article was to test three different types of cutters for machining material group N - nonferrous metals. The article was tested three different types of cutters from different vendors on electro material SKLOTEXTIT G 11 and samples size 12x100x500mm. The entire experiment was conducted in a company Slavík- Technické plasty on the machine tool SCM RECORD 220. In the conclusion are technical-evaluation, experimental results and conclusions for company.

  19. Chemical vapour deposition diamond coating on tungsten carbide dental cutting tools

    NASA Astrophysics Data System (ADS)

    Sein, H.; Ahmed, W.; Rego, C. A.; Jones, A. N.; Amar, M.; Jackson, M.; Polini, R.

    2003-10-01

    Diamond coatings on Co cemented tungsten carbide (WC-Co) hard metal tools are widely used for cutting non-ferrous metals. It is difficult to deposit diamond onto cutting tools, which generally have a complex geometry, using a single step growth process. This paper focuses on the deposition of polycrystalline diamond films onto dental tools, which possess 3D complex or cylindrical shape, employing a novel single step chemical vapour deposition (CVD) growth process. The diamond deposition is carried out in a hot filament chemical vapour deposition (HFCVD) reactor with a modified filament arrangement. The filament is mounted vertically with the drill held concentrically in between the filament coils, as opposed to the commonly used horizontal arrangement. This is a simple and inexpensive filament arrangement. In addition, the problems associated with adhesion of diamond films on WC-Co substrates are amplified in dental tools due to the very sharp edges and unpredictable cutting forces. The presence of Co, used as a binder in hard metals, generally causes poor adhesion. The amount of metallic Co on the surface can be reduced using a two step pre-treatment employing Murakami etching followed by an acid treatment. Diamond films are examined in terms of their growth rate, morphology, adhesion and cutting efficiency. We found that in the diamond coated dental tool the wear rate was reduced by a factor of three as compared to the uncoated tool.

  20. Artificial Intelligence Based Selection of Optimal Cutting Tool and Process Parameters for Effective Turning and Milling Operations

    NASA Astrophysics Data System (ADS)

    Saranya, Kunaparaju; John Rozario Jegaraj, J.; Ramesh Kumar, Katta; Venkateshwara Rao, Ghanta

    2016-06-01

    With the increased trend in automation of modern manufacturing industry, the human intervention in routine, repetitive and data specific activities of manufacturing is greatly reduced. In this paper, an attempt has been made to reduce the human intervention in selection of optimal cutting tool and process parameters for metal cutting applications, using Artificial Intelligence techniques. Generally, the selection of appropriate cutting tool and parameters in metal cutting is carried out by experienced technician/cutting tool expert based on his knowledge base or extensive search from huge cutting tool database. The present proposed approach replaces the existing practice of physical search for tools from the databooks/tool catalogues with intelligent knowledge-based selection system. This system employs artificial intelligence based techniques such as artificial neural networks, fuzzy logic and genetic algorithm for decision making and optimization. This intelligence based optimal tool selection strategy is developed using Mathworks Matlab Version 7.11.0 and implemented. The cutting tool database was obtained from the tool catalogues of different tool manufacturers. This paper discusses in detail, the methodology and strategies employed for selection of appropriate cutting tool and optimization of process parameters based on multi-objective optimization criteria considering material removal rate, tool life and tool cost.

  1. 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.

  2. New flame-cutting technique of vertical suspended pipe makes horizontal drilling tools

    SciTech Connect

    Not Available

    1986-08-01

    New methods of pipe cutting are being used to manufacture flexible drill collars for horizontal drilling. The flexible collars start as 20-ft lengths of 3.25 in. OD mild steel pipe with a wall thickness of 0.75 in. Every 11 in. along the length of the pipe, a baseball stitch pattern (also called light bulb pattern) is cut into the pipe, producing flexibility by degrees. The first cut allows the pipe to bend slightly at the gap. Each new cut adds about 2/sup 0/ flexibility. The resulting drill collar performs radical changes in well direction. These collars can turn 90/sup 0/ in a 30-ft radius for deflection to horizontal. This drilling method is used for drilling lateral wells or drainholes. The collars are manufactured for Parliament Properties' new venture, Sidewinder Tool Co., Tulsa, by H and M Pipe Beveling Machine Co. Inc., Tulsa.

  3. Is the present cut-point to define type 2 diabetes appropriate in Latin-Americans?

    PubMed

    López-Jaramillo, Patricio; Velandia-Carrillo, Carlos; Gómez-Arbeláez, Diego; Aldana-Campos, Martin

    2014-12-15

    The diagnosis of diabetes mellitus type 2 (DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each population according to their metabolic characteristics, given that these may vary in each population. The World Health Organization (WHO) determined the cut-points of plasma glucose levels for the diagnosis of DM2 by associating hyperglycemia with the risk of a specific microvascular complication-retinopathy. Cardiovascular diseases are however the principal causes of mortality in patients with DM2 and we reported that in the Colombo-Ecuadorian population impaired fasting glucose and impaired glucose tolerance are both risk markers for myocardial infarction. We propose that the current cut-points accepted by the WHO need to be revaluated in populations such as Latin America and that there should be lower cut points for glycaemia in this population, to reduce the prevalence of cardiovascular complications associated with DM2. PMID:25512777

  4. Is the present cut-point to define type 2 diabetes appropriate in Latin-Americans?

    PubMed Central

    López-Jaramillo, Patricio; Velandia-Carrillo, Carlos; Gómez-Arbeláez, Diego; Aldana-Campos, Martin

    2014-01-01

    The diagnosis of diabetes mellitus type 2 (DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each population according to their metabolic characteristics, given that these may vary in each population. The World Health Organization (WHO) determined the cut-points of plasma glucose levels for the diagnosis of DM2 by associating hyperglycemia with the risk of a specific microvascular complication-retinopathy. Cardiovascular diseases are however the principal causes of mortality in patients with DM2 and we reported that in the Colombo-Ecuadorian population impaired fasting glucose and impaired glucose tolerance are both risk markers for myocardial infarction. We propose that the current cut-points accepted by the WHO need to be revaluated in populations such as Latin America and that there should be lower cut points for glycaemia in this population, to reduce the prevalence of cardiovascular complications associated with DM2. PMID:25512777

  5. Creation Of The Residual Stress By Influence Of Wear Of Cutting Tool And Their Analysis

    NASA Astrophysics Data System (ADS)

    Kordík, Marek; Čilliková, Mária; Mrazik, Jozef; Martinček, Juraj; Janota, Miroslav; Nicielnik, Henryk

    2015-12-01

    The aim of this paper is analysis of turned bearing ring made of material 14109 (DIN 100Cr6) without heat treatment. For the analysis a mechanical destructive method was chosen. Analysis focused on existence and character of residual stresses after turning operation of bearing ring by tool with different level of wear. The experiment reveals the relationships between residual stress creation and cutting tool wear.

  6. 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…

  7. Detection of fallen trees in ALS point clouds using a Normalized Cut approach trained by simulation

    NASA Astrophysics Data System (ADS)

    Polewski, Przemyslaw; Yao, Wei; Heurich, Marco; Krzystek, Peter; Stilla, Uwe

    2015-07-01

    Downed dead wood is regarded as an important part of forest ecosystems from an ecological perspective, which drives the need for investigating its spatial distribution. Based on several studies, Airborne Laser Scanning (ALS) has proven to be a valuable remote sensing technique for obtaining such information. This paper describes a unified approach to the detection of fallen trees from ALS point clouds based on merging short segments into whole stems using the Normalized Cut algorithm. We introduce a new method of defining the segment similarity function for the clustering procedure, where the attribute weights are learned from labeled data. Based on a relationship between Normalized Cut's similarity function and a class of regression models, we show how to learn the similarity function by training a classifier. Furthermore, we propose using an appearance-based stopping criterion for the graph cut algorithm as an alternative to the standard Normalized Cut threshold approach. We set up a virtual fallen tree generation scheme to simulate complex forest scenarios with multiple overlapping fallen stems. This simulated data is then used as a basis to learn both the similarity function and the stopping criterion for Normalized Cut. We evaluate our approach on 5 plots from the strictly protected mixed mountain forest within the Bavarian Forest National Park using reference data obtained via a manual field inventory. The experimental results show that our method is able to detect up to 90% of fallen stems in plots having 30-40% overstory cover with a correctness exceeding 80%, even in quite complex forest scenes. Moreover, the performance for feature weights trained on simulated data is competitive with the case when the weights are calculated using a grid search on the test data, which indicates that the learned similarity function and stopping criterion can generalize well on new plots.

  8. Modelling of tunnelling processes and rock cutting tool wear with the particle finite element method

    NASA Astrophysics Data System (ADS)

    Carbonell, Josep Maria; Oñate, Eugenio; Suárez, Benjamín

    2013-09-01

    Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are growing, and so safety and security demands do. New engineering tools are needed to perform a safer planning and design. This work presents the advances in the particle finite element method (PFEM) for the modelling and the analysis of tunneling processes including the wear of the cutting tools. The PFEM has its foundation on the Lagrangian description of the motion of a continuum built from a set of particles with known physical properties. The method uses a remeshing process combined with the alpha-shape technique to detect the contacting surfaces and a finite element method for the mechanical computations. A contact procedure has been developed for the PFEM which is combined with a constitutive model for predicting the excavation front and the wear of cutting tools. The material parameters govern the coupling of frictional contact and wear between the interacting domains at the excavation front. The PFEM allows predicting several parameters which are relevant for estimating the performance of a tunnelling boring machine such as wear in the cutting tools, the pressure distribution on the face of the boring machine and the vibrations produced in the machinery and the adjacent soil/rock. The final aim is to help in the design of the excavating tools and in the planning of the tunnelling operations. The applications presented show that the PFEM is a promising technique for the analysis of tunnelling problems.

  9. Performance of Process Damping in Machining Titanium Alloys at Low Cutting Speed with Different Helix Tools

    NASA Astrophysics Data System (ADS)

    Shaharun, M. A.; Yusoff, A. R.; Reza, M. S.; Jalal, K. A.

    2012-09-01

    Titanium is a strong, lustrous, corrosion-resistant and transition metal with a silver color to produce strong lightweight alloys for industrial process, automotive, medical instruments and other applications. However, it is very difficult to machine the titanium due to its poor machinability. When machining titanium alloys with the conventional tools, the wear rate of the tool is rapidly accelerate and it is generally difficult to achieve at high cutting speed. In order to get better understanding of machining titanium alloy, the interaction between machining structural system and the cutting process which result in machining instability will be studied. Process damping is a useful phenomenon that can be exploited to improve the limited productivity of low speed machining. In this study, experiments are performed to evaluate the performance of process damping of milling under different tool helix geometries. The results showed that the helix of 42° angle is significantly increase process damping performance in machining titanium alloy.

  10. Application of CBR method for adding the process of cutting tools and parameters selection

    NASA Astrophysics Data System (ADS)

    Ociepka, P.; Herbus, K.

    2015-11-01

    Modem enterprises must face with the dynamically changing market demand what influences the designing process. It is possible by linking computer tools with information gathered by experienced designers teams. The article describes the method basing on engineering knowledge and experience to adding the process of tools selection and cutting parameters determination for a turning operation. The method, proposed by the authors, is based on the CBR (Case Based Reasoning) method. CBR is a method of problem solving that involves searching for an analogy (similarity) between the current task to be solved, and the earlier cases that properly described, are stored in a computer memory. This article presents an algorithm and a formalized description of the developed method. It was discussed the range of its utilization, as well as it was illustrated the method of its functioning on the example of the tools and cutting parameters selection with respect to the turning process.

  11. Heuristic algorithms for solving of the tool routing problem for CNC cutting machines

    NASA Astrophysics Data System (ADS)

    Chentsov, P. A.; Petunin, A. A.; Sesekin, A. N.; Shipacheva, E. N.; Sholohov, A. E.

    2015-11-01

    The article is devoted to the problem of minimizing the path of the cutting tool to shape cutting machines began. This problem can be interpreted as a generalized traveling salesman problem. Earlier version of the dynamic programming method to solve this problem was developed. Unfortunately, this method allows to process an amount not exceeding thirty circuits. In this regard, the task of constructing quasi-optimal route becomes relevant. In this paper we propose options for quasi-optimal greedy algorithms. Comparison of the results of exact and approximate algorithms is given.

  12. Preset pivotal tool holder

    DOEpatents

    Asmanes, Charles

    1979-01-01

    A tool fixture is provided for precise pre-alignment of a radiused edge cutting tool in a tool holder relative to a fixed reference pivot point established on said holder about which the tool holder may be selectively pivoted relative to the fixture base member to change the contact point of the tool cutting edge with a workpiece while maintaining the precise same tool cutting radius relative to the reference pivot point.

  13. Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

    NASA Astrophysics Data System (ADS)

    Sulaiman, S.; Roshan, A.; Ariffin, M. K. A.

    2013-12-01

    In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes.

  14. Cutting tool temperatures in contour turning: Transient analysis and experimental verification

    SciTech Connect

    Stephenson, D.A.; Jen, T.C.; Lavine, A.S.

    1995-12-31

    This paper describes a model for predicting cutting tool temperatures under transient conditions. It is applicable to processes such as contour turning, in which the cutting speed, feed rate, and depth of cut may vary continuously with time. The model is intended for use in process development and trouble shooting. Therefore, emphasis is given in the model development to enable rapid computation and to avoid the need to specify parameters such as thermal contact resistances and convection coefficients which are not known in practice. Experiments were conducted to validate the predictive model. The model predictions with two different boundary conditions bound the experimental results. An example is presented which shows the utility of the model for process planning.

  15. Prototype of Partial Cutting Tool of Geological Map Images Distributed by Geological Web Map Service

    NASA Astrophysics Data System (ADS)

    Nonogaki, S.; Nemoto, T.

    2014-12-01

    Geological maps and topographical maps play an important role in disaster assessment, resource management, and environmental preservation. These map information have been distributed in accordance with Web services standards such as Web Map Service (WMS) and Web Map Tile Service (WMTS) recently. In this study, a partial cutting tool of geological map images distributed by geological WMTS was implemented with Free and Open Source Software. The tool mainly consists of two functions: display function and cutting function. The former function was implemented using OpenLayers. The latter function was implemented using Geospatial Data Abstraction Library (GDAL). All other small functions were implemented by PHP and Python. As a result, this tool allows not only displaying WMTS layer on web browser but also generating a geological map image of intended area and zoom level. At this moment, available WTMS layers are limited to the ones distributed by WMTS for the Seamless Digital Geological Map of Japan. The geological map image can be saved as GeoTIFF format and WebGL format. GeoTIFF is one of the georeferenced raster formats that is available in many kinds of Geographical Information System. WebGL is useful for confirming a relationship between geology and geography in 3D. In conclusion, the partial cutting tool developed in this study would contribute to create better conditions for promoting utilization of geological information. Future work is to increase the number of available WMTS layers and the types of output file format.

  16. An analytical method on the surface residual stress for the cutting tool orientation

    NASA Astrophysics Data System (ADS)

    Li, Yueen; Zhao, Jun; Wang, Wei

    2009-12-01

    The residual stress is measured by choosing 8 kinds orientations on cutting the H13 dies steel on the HSM in the experiment of this paper. The measured data shows on that the residual stress exists periodicity for the different rake angle (β) and side rake angle (θ) parameters, further study find that the cutting tool orientations have closed relationship with the residual stresses, and for the original of the machined residual stress on the surface from the cutting force and the axial force, it can be gained the simply model of tool-workpiece force, using the model it can be deduced the residual stress model, which is feasible to calculate the size of residual stress. And for almost all the measured residual stresses are compressed stress, the compressed stress size and the direction could be confirmed by the input data for the H13 on HSM. As the result, the residual stress model is the key for optimization of rake angle (β) and side rake angle (θ) in theory, using the theory the more cutting mechanism can be expressed.

  17. An analytical method on the surface residual stress for the cutting tool orientation

    NASA Astrophysics Data System (ADS)

    Li, Yueen; Zhao, Jun; Wang, Wei

    2010-03-01

    The residual stress is measured by choosing 8 kinds orientations on cutting the H13 dies steel on the HSM in the experiment of this paper. The measured data shows on that the residual stress exists periodicity for the different rake angle (β) and side rake angle (θ) parameters, further study find that the cutting tool orientations have closed relationship with the residual stresses, and for the original of the machined residual stress on the surface from the cutting force and the axial force, it can be gained the simply model of tool-workpiece force, using the model it can be deduced the residual stress model, which is feasible to calculate the size of residual stress. And for almost all the measured residual stresses are compressed stress, the compressed stress size and the direction could be confirmed by the input data for the H13 on HSM. As the result, the residual stress model is the key for optimization of rake angle (β) and side rake angle (θ) in theory, using the theory the more cutting mechanism can be expressed.

  18. Laser forming cutting once quenched high-speed tool steel (HSTS) disk-shaped milling cutter

    NASA Astrophysics Data System (ADS)

    Ding, Zhihong; Liu, Yongzhen; Weng, Shiping

    1998-08-01

    Laser cutting technology has been applied to ordinary alloy steel circular sawblade, but it is very rarely used in quenched HSTS disk-shape milling-cutters due to the material particularity. In this paper, the authors systematically explain the advantages of this new technique, respecting the optimum design of HSTS disk-shape milling-cutter, the specific characteristics of laser forming cutting once for all, the technology testing, the analysis of structural performance of tooth and the small batch production for verifying. The article displays its advantages completely as follows: The design for a perfect tooth profile is not bound to the ordinary machining methods; The special laser technique does not lower the hardness on the tooth nose so that this process and needs no follow-up operational sequences, ensures the excellent dynamic-balance performance and operation properties, and prolongs the tools' service time; The new technique also has advantages of high efficiency and good economics. Therefore, this special laser cutting method, an integration of intensified heat-treatment and laser forming cutting once for all technology, will be regarded as a reform in HSTS tools Manufacturing field.

  19. Defining a BMI Cut-Off Point for the Iranian Population: The Shiraz Heart Study.

    PubMed

    Babai, Mohammad Ali; Arasteh, Peyman; Hadibarhaghtalab, Maryam; Naghizadeh, Mohammad Mehdi; Salehi, Alireza; Askari, Alireza; Homayounfar, Reza

    2016-01-01

    In this study we evaluated and redefined the optimum body mass index (BMI) cut-off point for the Iranian population based on metabolic syndrome (MeS) risk factors. We further evaluated BMI cut-off points with and without waist circumference (WC) as a cofactor of risk and compared the differences. This study is part of the largest surveillance programs conducted in Shiraz, Iran, termed the Shiraz Heart study. Our study sample included subjects between the ages of 20 to 65 years old. After excluding pregnant women, those with missing data and those with comorbid disease, a total of 12283 made up the study population. The participants underwent a series of tests and evaluations by trained professionals in accordance with WHO recommendations. Hypertension, abnormal fasting blood sugar (FBS), triglyceride (TG) and high density lipoprotein cholesterol (HDL) (in the context of the definition of metabolic syndrome) were prevalent among 32.4%, 27.6%, 42.1 and 44.2% of our participants, respectively. Women displayed higher rates of overall obesity compared to men (based on the definition by the WHO as higher than 30 kg/m2). Regarding MeS, 38.9% of our population had the all symptoms of MeS which was more prevalent among women (41.5% vs. 36%). When excluding WC in the definition of MeS, results showed that males tend to show a higher rate of metabolic risk factors (19.2% vs. 15.6%). Results of multivariate analysis showed that parallel to an increase in BMI, the odds ratio (OR) for acquiring each component of the metabolic syndrome increased (OR = 1.178; CI: 1.166-1.190). By excluding WC, the previous OR decreased (OR = 1.105; CI: 1.093-1.118). Receiver Operating Characteristic (ROC) curve analysis showed that the optimum BMI cut-off point for predicting metabolic syndrome was 26.1 kg/m2 and 26.2 kg/m2 [Accuracy (Acc) = 69% and 61%, respectively)] for males and females, respectively. The overall BMI cut-off for both sexes was 26.2 kg/m2 (Acc = 65%) with sensitivity and

  20. Defining a BMI Cut-Off Point for the Iranian Population: The Shiraz Heart Study

    PubMed Central

    Babai, Mohammad Ali; Arasteh, Peyman; Hadibarhaghtalab, Maryam; Naghizadeh, Mohammad Mehdi; Salehi, Alireza; Askari, Alireza; Homayounfar, Reza

    2016-01-01

    In this study we evaluated and redefined the optimum body mass index (BMI) cut-off point for the Iranian population based on metabolic syndrome (MeS) risk factors. We further evaluated BMI cut-off points with and without waist circumference (WC) as a cofactor of risk and compared the differences. This study is part of the largest surveillance programs conducted in Shiraz, Iran, termed the Shiraz Heart study. Our study sample included subjects between the ages of 20 to 65 years old. After excluding pregnant women, those with missing data and those with comorbid disease, a total of 12283 made up the study population. The participants underwent a series of tests and evaluations by trained professionals in accordance with WHO recommendations. Hypertension, abnormal fasting blood sugar (FBS), triglyceride (TG) and high density lipoprotein cholesterol (HDL) (in the context of the definition of metabolic syndrome) were prevalent among 32.4%, 27.6%, 42.1 and 44.2% of our participants, respectively. Women displayed higher rates of overall obesity compared to men (based on the definition by the WHO as higher than 30 kg/m2). Regarding MeS, 38.9% of our population had the all symptoms of MeS which was more prevalent among women (41.5% vs. 36%). When excluding WC in the definition of MeS, results showed that males tend to show a higher rate of metabolic risk factors (19.2% vs. 15.6%). Results of multivariate analysis showed that parallel to an increase in BMI, the odds ratio (OR) for acquiring each component of the metabolic syndrome increased (OR = 1.178; CI: 1.166–1.190). By excluding WC, the previous OR decreased (OR = 1.105; CI: 1.093–1.118). Receiver Operating Characteristic (ROC) curve analysis showed that the optimum BMI cut-off point for predicting metabolic syndrome was 26.1 kg/m2 and 26.2 kg/m2 [Accuracy (Acc) = 69% and 61%, respectively)] for males and females, respectively. The overall BMI cut-off for both sexes was 26.2 kg/m2 (Acc = 65%) with sensitivity and

  1. Correction method for the error of diamond tool's radius in ultra-precision cutting

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Yu, Jing-chi

    2010-10-01

    The compensation method for the error of diamond tool's cutting edge is a bottle-neck technology to hinder the high accuracy aspheric surface's directly formation after single diamond turning. Traditional compensation was done according to the measurement result from profile meter, which took long measurement time and caused low processing efficiency. A new compensation method was firstly put forward in the article, in which the correction of the error of diamond tool's cutting edge was done according to measurement result from digital interferometer. First, detailed theoretical calculation related with compensation method was deduced. Then, the effect after compensation was simulated by computer. Finally, φ50 mm work piece finished its diamond turning and new correction turning under Nanotech 250. Testing surface achieved high shape accuracy pv 0.137λ and rms=0.011λ, which approved the new compensation method agreed with predictive analysis, high accuracy and fast speed of error convergence.

  2. A review of the use of wear-resistant coatings in the cutting-tool industry

    NASA Technical Reports Server (NTRS)

    Salik, J.

    1983-01-01

    The main mechanisms involved in the wear of cutting tools are reviewed. Evaluation of the different coating properties required for the reduction of the different kinds of wear was also reviewed. The types of coatings and their ranges of applicability are presented and discussed in view of their properties. Various coating processes as well as their advantages and shortcomings are described. Potential future developments in the field of wear-resistant coatings are discussed.

  3. Research concerning optimum cutting parameters according with tool path strategy for finishing procedures

    NASA Astrophysics Data System (ADS)

    Pena, A. E.; Anania, F. D.; Zapciu, M.

    2015-11-01

    Optimization of cutting parameters in NC milling needs to be studied because of its influence on machining time and cost. Today, any CAM software offers many tool path strategies to milling free form geometries. However, the users must have the know-how to choose the strategies according to geometry complexity, cutting tool geometry and its contact on the machined surface. Choosing the right strategy with the right cutting parameter is a rather difficult task to do on the machine tool. In this paper we try to take into account the influence of the toolpath over the surface quality for finishing operation. The main goal is to establish a direct link between machining parameters and toolpath in order to obtain the same surface quality for different trajectories. The first step consist in making a series of experiments for standards toolpaths (which can be found in any CAM software) like one-way, zig-zag, spiral from outside to inside, zig-zag at 45 dgr on a milling center. Based on the results, a correction coefficient for the feed rate was established.

  4. Automatic registration method for multisensor datasets adopted for dimensional measurements on cutting tools

    NASA Astrophysics Data System (ADS)

    Shaw, L.; Ettl, S.; Mehari, F.; Weckenmann, A.; Häusler, G.

    2013-04-01

    Multisensor systems with optical 3D sensors are frequently employed to capture complete surface information by measuring workpieces from different views. During coarse and fine registration the resulting datasets are afterward transformed into one common coordinate system. Automatic fine registration methods are well established in dimensional metrology, whereas there is a deficit in automatic coarse registration methods. The advantage of a fully automatic registration procedure is twofold: it enables a fast and contact-free alignment and further a flexible application to datasets of any kind of optical 3D sensor. In this paper, an algorithm adapted for a robust automatic coarse registration is presented. The method was originally developed for the field of object reconstruction or localization. It is based on a segmentation of planes in the datasets to calculate the transformation parameters. The rotation is defined by the normals of three corresponding segmented planes of two overlapping datasets, while the translation is calculated via the intersection point of the segmented planes. First results have shown that the translation is strongly shape dependent: 3D data of objects with non-orthogonal planar flanks cannot be registered with the current method. In the novel supplement for the algorithm, the translation is additionally calculated via the distance between centroids of corresponding segmented planes, which results in more than one option for the transformation. A newly introduced measure considering the distance between the datasets after coarse registration evaluates the best possible transformation. Results of the robust automatic registration method are presented on the example of datasets taken from a cutting tool with a fringe-projection system and a focus-variation system. The successful application in dimensional metrology is proven with evaluations of shape parameters based on the registered datasets of a calibrated workpiece.

  5. Proposing a Tentative Cut Point for the Compulsive Sexual Behavior Inventory

    PubMed Central

    Storholm, Erik David; Fisher, Dennis G.; Napper, Lucy E.; Reynolds, Grace L.

    2015-01-01

    Bivariate analyses were utilized in order to identify the relations between scores on the Compulsive Sexual Behavior Inventory (CSBI) and self-report of risky sexual behavior and drug abuse among 482 racially and ethnically diverse men and women. CSBI scores were associated with both risky sexual behavior and drug abuse among a diverse non-clinical sample, thereby providing evidence of criterion-related validity. The variables that demonstrated a high association with the CSBI were subsequently entered into a multiple regression model. Four variables (number of sexual partners in the last 30 days, self-report of trading drugs for sex, having paid for sex, and perceived chance of acquiring HIV) were retained as variables with good model fit. Receiver operating characteristic (ROC) curve analyses were conducted in order to determine the optimal tentative cut point for the CSBI. The four variables retained in the multiple regression model were utilized as exploratory gold standards in order to construct ROC curves. The ROC curves were then compared to one another in order to determine the point that maximized both sensitivity and specificity in the identification of compulsive sexual behavior with the CSBI scale. The current findings suggest that a tentative cut point of 40 may prove clinically useful in discriminating between persons who exhibit compulsive sexual behavior and those who do not. Because of the association between compulsive sexual behavior and HIV, STIs, and drug abuse, it is paramount that a psychometrically sound measure of compulsive sexual behavior is made available to all healthcare professionals working in disease prevention and other areas. PMID:21203814

  6. Design and fabrication of nano-scale single crystal diamond cutting tool by focused ion beam (FIB) milling

    NASA Astrophysics Data System (ADS)

    Baek, Seung-Yub

    2015-07-01

    Micro/nanoscale diamond cutting tools used in ultra-precision machining can be fabricated by precision grinding, but it is hard to fabricate a tool with a nanometric cutting edge and complex configurations. High-precision geometry accuracy and special shapes for microcutting tools with sharp edges can be achieved by FIB milling. Because the FIB milling method induces much smaller machining stress compared with conventional precision grinding methods. In this study, the FIB milling characteristics of single-crystal diamond were investigated, along with methods for decreasing the FIB-induced damage on diamond tools. Lift-off process method and Pt(Platinum) coating process method with FIB milling were investigated to reduce the damage layer on diamond substrate and quadrilateral-shaped single-crystal diamond cutting tool with cutting edge width under 500 nm were obtained.

  7. Vibration suppression in cutting tools using collocated piezoelectric sensors/actuators with an adaptive control algorithm

    SciTech Connect

    Radecki, Peter P; Farinholt, Kevin M; Park, Gyuhae; Bement, Matthew T

    2008-01-01

    The machining process is very important in many engineering applications. In high precision machining, surface finish is strongly correlated with vibrations and the dynamic interactions between the part and the cutting tool. Parameters affecting these vibrations and dynamic interactions, such as spindle speed, cut depth, feed rate, and the part's material properties can vary in real-time, resulting in unexpected or undesirable effects on the surface finish of the machining product. The focus of this research is the development of an improved machining process through the use of active vibration damping. The tool holder employs a high bandwidth piezoelectric actuator with an adaptive positive position feedback control algorithm for vibration and chatter suppression. In addition, instead of using external sensors, the proposed approach investigates the use of a collocated piezoelectric sensor for measuring the dynamic responses from machining processes. The performance of this method is evaluated by comparing the surface finishes obtained with active vibration control versus baseline uncontrolled cuts. Considerable improvement in surface finish (up to 50%) was observed for applications in modern day machining.

  8. Multivariate meta-analysis of prognostic factor studies with multiple cut-points and/or methods of measurement.

    PubMed

    Riley, Richard D; Elia, Eleni G; Malin, Gemma; Hemming, Karla; Price, Malcolm P

    2015-07-30

    A prognostic factor is any measure that is associated with the risk of future health outcomes in those with existing disease. Often, the prognostic ability of a factor is evaluated in multiple studies. However, meta-analysis is difficult because primary studies often use different methods of measurement and/or different cut-points to dichotomise continuous factors into 'high' and 'low' groups; selective reporting is also common. We illustrate how multivariate random effects meta-analysis models can accommodate multiple prognostic effect estimates from the same study, relating to multiple cut-points and/or methods of measurement. The models account for within-study and between-study correlations, which utilises more information and reduces the impact of unreported cut-points and/or measurement methods in some studies. The applicability of the approach is improved with individual participant data and by assuming a functional relationship between prognostic effect and cut-point to reduce the number of unknown parameters. The models provide important inferential results for each cut-point and method of measurement, including the summary prognostic effect, the between-study variance and a 95% prediction interval for the prognostic effect in new populations. Two applications are presented. The first reveals that, in a multivariate meta-analysis using published results, the Apgar score is prognostic of neonatal mortality but effect sizes are smaller at most cut-points than previously thought. In the second, a multivariate meta-analysis of two methods of measurement provides weak evidence that microvessel density is prognostic of mortality in lung cancer, even when individual participant data are available so that a continuous prognostic trend is examined (rather than cut-points). PMID:25924725

  9. Establishing school day pedometer step count cut-points using ROC curves in low-income children.

    PubMed

    Burns, Ryan D; Brusseau, Timothy A; Fu, You; Hannon, James C

    2016-05-01

    Previous research has not established pedometer step count cut-points that discriminate children that meet school day physical activity recommendations using a tri-axial ActiGraph accelerometer criterion. The purpose of this study was to determine step count cut-points that associate with 30min of school day moderate-to-vigorous physical activity (MVPA) in school-aged children. Participants included 1053 school-aged children (mean age=8.4±1.8years) recruited from three low-income schools from the state of Utah in the U.S. Physical activity was assessed using Yamax DigiWalker CW600 pedometers and ActiGraph wGT3X-BT triaxial accelerometers that were concurrently worn during school hours. Data were collected at each school during the 2014-2015 school year. Receiver operating characteristic (ROC) curves were used to determine pedometer step count cut-points that associated with at least 30min of MVPA during school hours. Cut-points were determined using the maximum Youden's J statistic (J max). For the total sample, the area-under-the-curve (AUC) was 0.77 (p<0.001) with a pedometer cut-point of 5505 steps (J max=0.46, Sensitivity=63%, Specificity=84%; Accuracy=76%). Step counts showed greater diagnostic ability in girls (AUC=0.81, p<0.001; Cut-point=5306 steps; Accuracy=78.8%) compared to boys (AUC=0.72, p<0.01; Cut-point=5786 steps; Accuracy=71.4%). Pedometer step counts showed good diagnostic ability in girls and fair diagnostic ability in boys for discriminating children that met at least 30min of MVPA during school hours. PMID:26876627

  10. Studies of the frictional heating of polycrystalline diamond compact drag tools during rock cutting

    SciTech Connect

    Ortega, A.; Glowka, D.A.

    1982-06-01

    A numerical-analytical model is developed to analyze temperatures in polycrystalline diamond compact (PDC) drag tools subject to localized frictional heating at a worn flat area and convective cooling at exposed lateral surfaces. Experimental measurements of convective heat transfer coefficients of PDC cutters in a uniform crossflow are presented and used in the model to predict temperatures under typical drilling conditions with fluid flow. The analysis compares favorably with measurements of frictional temperatures in controlled cutting tests on Tennessee marble. It is found that average temperatures at the wearflat contact zone vary directly with frictional force per unit area and are proportional to the one-half power of the cutting speed at the velocities investigated. Temperatures are found to be much more sensitive to decreases in the dynamic friction by lubrication than to increases in convective cooling rates beyond currently achievable levels with water or drilling fluids. It is shown that use of weighted drilling fluids may actually decrease cooling rates compared to those achieved with pure water. It is doubtful that tool temperatures can be kept below critical levels (750/sup 0/C) if air is employed as the drilling fluid. The degree of tool wear is found to have a major influence on the thermal response of the friction contact zone, so that for equal heating per contact area, a worn tool will run much hotter than a sharp tool. It is concluded that tool temperatures may be kept below critical levels with conventional water or mud cooling as long as the fluid provides good cutter-rock lubrication.

  11. A measurement method of cutting tool position for relay fabrication of microstructured surface

    NASA Astrophysics Data System (ADS)

    Chen, Yuan-Liu; Gao, Wei; Ju, Bing-Feng; Shimizu, Yuki; Ito, So

    2014-06-01

    By using the secondary function of a force sensor integrated fast tool servo (FTS) for surface profile measurement, the three-dimensional tip position of a micro-cutting tool in the FTS with respect to the fabricated microstructures was measured without using any additional instrument for realizing the concept of relay fabrication of microstructured surface. It was verified from the experiments for testing the basic performances of tool tip position measurement that the delay of the force feedback control loop of the FTS was a big factor influencing the position measurement accuracy. A bidirectional scanning strategy was then employed to reduce the position measurement error due to the delay of the feedback control loop. Tool tip position measurement experiments by using micro-tools with a nose radius of 100 µm for relay fabrications with sub-micrometer accuracies, including stitching fabrication of a micro-groove line array and filling fabrication of a microlens lattice pattern, were carried out to demonstrate the feasibility of the tool position measurement method.

  12. Available Tools and Challenges Classifying Cutting-Edge and Historical Astronomical Documents

    NASA Astrophysics Data System (ADS)

    Lagerstrom, Jill

    2015-08-01

    The STScI Library assists the Science Policies Division in evaluating and choosing scientific keywords and categories for proposals for the Hubble Space Telescope mission and the upcoming James Webb Space Telescope mission. In addition we are often faced with the question “what is the shape of the astronomical literature?” However, subject classification in astronomy in recent times has not been cultivated. This talk will address the available tools and challenges of classifying cutting-edge as well as historical astronomical documents. In at the process, we will give an overview of current and upcoming practices of subject classification in astronomy.

  13. Machinability of hastelloy C-276 using Hot-pressed sintered Ti(C7N3)-based cermet cutting tools

    NASA Astrophysics Data System (ADS)

    Xu, Kaitao; Zou, Bin; Huang, Chuanzhen; Yao, Yang; Zhou, Huijun; Liu, Zhanqiang

    2015-05-01

    C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent failure mode due to high mechanical properties of work piece, which results in the short tool life and low productivity. In this paper, a newly developed Ti(C7N3)-based cermet insert manufactured by a hot-pressing method is used to machine the C-276 nickel-based alloy, and its cutting performances are studied. Based on orthogonal experiment method, the influence of cutting parameters on tool life, material removal rates and surface roughness are investigated. Experimental research results indicate that the optimal cutting condition is a cutting speed of 50 m/min, depth of cut of 0.4 mm and feed rate of 0.15 mm/r if the tool life and material removal rates are considered comprehensively. In this case, the tool life is 32 min and material removal rates are 3000 mm3/min, which is appropriate to the rough machining. If the tool life and surface roughness are considered, the better cutting condition is a cutting speed of 75 m/min, depth of cut of 0.6 mm and feed rate of 0.1 mm/r. In this case, the surface roughness is 0.59μm. Notch wear, flank wear, chipping at the tool nose, built-up edge(BUE) and micro-cracks are found when Ti(C7N3)-based cermet insert turned Hastelloy C-276. Oxidation, adhesive, abrasive and diffusion are the wear mechanisms, which can be investigated by the observations of scanning electron microscope and energy-dispersive spectroscopy. This research will help to guide studies on the evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy C-276 machining.

  14. Pediatric Care Online: A Pediatric Point-of-Care Tool.

    PubMed

    Vardell, Emily

    2016-01-01

    Pediatric Care Online is the American Academy of Pediatrics' point-of-care tool designed for health care providers. Pediatric Care Online builds on content from Red Book Online and Pediatric Patient Education and features Quick Reference topic pages for more than 250 pediatric health care topics. The multitude of resources available within Pediatric Care Online will be reviewed in this column, and a sample search will be used to illustrate the type of information available within this point-of-care pediatric resource. PMID:27054536

  15. Addressing drug effects on cut point determination for an anti-drug antibody assay.

    PubMed

    Barbosa, Maria D F S; Gleason, Carol R; Phillips, Kelli R; Berisha, Flora; Stouffer, Bruce; Warrack, Bethanne M; Chen, Guodong

    2012-10-31

    The effect of trough levels of a monoclonal antibody drug (drugB) on screening cut point (CP) determination for an anti-drug antibody (ADA) assay was scrutinized and the conclusions substantiated by data from a phase 3 cancer clinical study. The ADA assay utilized an acid dissociation step and either 0 or 100 μg/ml drugB was added to the samples prior to obtaining the signals used for CP calculations. Serum samples from three different drug-naive populations were tested (healthy individuals, cancer patients enrolled in the drugB clinical trial and cancer patients whose serum samples were available commercially). For the same disease state samples, both the screening CP and confirmation CP were different when calculated during validation or from study sample analysis. It is reasonable to assume that variability was due to the patient heterogeneity, as they could have been at distinct stages of disease progression, and/or taking different medications, amongst other differences. The patients enrolled in the clinical trial were stratified as per protocol and hence represented a more homogeneous population. Drug effects on CP may be population dependent and also assay dependent. PMID:22750627

  16. Fetus as Human Being: Where is the Cut-off Point?

    PubMed Central

    Dabbagh, Soroush

    2009-01-01

    Abortion is one of the controversial issues discussed in medical ethics. We can formulate the argument which is put forward by the opponents of abortion as follows: 1) fetus has to be regarded as human being; 2) killing an innocent human being is morally wrong; 3) aborting is an example of killing and terminating a human being’s life. So, being engaged in aborting is morally wrong. In this paper, I am going to argue that the proponents’ argument with regard to the implausibility of categorizing fetus as human being is unjustified and wanting. In other words, the way in which the proponents of abortion talk about the idea of personhood is, inadequate and vague, semantically speaking. The outline of the argument is as follows. The proponents of abortion are confronted with a dilemma. According to the first horn of the dilemma, the proponents have to subscribe to infanticide which is morally wrong, intuitively speaking. According to the second horn of the dilemma, there is a semantic story which needs to be expressed by the proponents with regard to the cut-off point of the concept ‘personhood’. Otherwise, the first premise will not be convincing if raised in favour of the plausibility of committing abortion. PMID:23908716

  17. A review of the cut-off points for the diagnosis of vitamin B12 deficiency in the general population.

    PubMed

    Aparicio-Ugarriza, Raquel; Palacios, Gonzalo; Alder, Monika; González-Gross, Marcela

    2015-07-01

    Vitamin B12 deficit is one of the most common vitamin deficiencies. However, there is no consensus on the cut-off points for vitamin B12 and its co-markers, such as folate, holotranscobalamin, methylmalonic acid and homocysteine. In order to establish the state of the art about cut-off points used to determine vitamin B12 deficiency in the last decades, the database MEDLINE was used for searching studies published in adults between December 1992 and May 2014 (69 articles), using search terms like 'vitamin B12', 'cobalamin', 'cut-off', 'deficiency' alone or in combinations. Broad ranges of cut-off points for vitamin B12 and its biomarkers were identified: vitamin B12 ranged between 100 pmol/L and 350 pmol/L, holotranscobalamin 20-50 pmol/L, methylmalonic acid 0.210-0.470 μmol/L, homocysteine 10-21.6 μmol/L, serum folate 3.7-15.9 nmol/L and red blood cell 124-397 nmol/L. For the majority of studies, the potential influence of age, analytical methods, gender and fortified food consumption was not taken in account when choosing cut-off values. This could explain the discrepancies between studies on vitamin B12 and folate deficiency prevalences. We conclude that there is inconsistency in the literature regarding vitamin B12 cut-offs. It would be necessary to establish different reference cut-offs according to age, considering the analytical methods used. PMID:25470607

  18. An approach based on tool mode control for surface roughness reduction in high-frequency vibration cutting

    NASA Astrophysics Data System (ADS)

    Ostasevicius, V.; Gaidys, R.; Rimkeviciene, J.; Dauksevicius, R.

    2010-11-01

    The presented research work, aimed at deeper understanding of vibrational process during high-frequency vibration cutting, is accomplished by treating cutting tool as an elastic structure which is characterized by several modes of natural vibrations. An approach for surface quality improvement is proposed in this paper by taking into account that quality of machined surface is related to the intensity of tool-tip (cutting edge) vibrations. It is based on the excitation of a particular higher vibration mode of a turning tool, which leads to the reduction of deleterious vibrations in the machine-tool-workpiece system through intensification of internal energy dissipation in the tool material. The combined application of numerical analysis with accurate finite element model as well as different experimental methods during investigation of the vibration turning process allowed to determine that the most favorable is the second flexural vibration mode of the tool in the direction of vertical cutting force component. This mode is excited by means of piezoelectric transducer vibrating in axial tool direction at the corresponding natural frequency, thereby enabling minimization of surface roughness and tool wear.

  19. Surface Quality of Ti-6%Al-4%V ELI When Machined Using CVD-Carbide Tools at High Cutting Speed

    SciTech Connect

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.; Yasir, A.; Zaid, Y.; Yanuar, B.

    2011-01-17

    Machining of Ti-6Al-4V ELI becomes more interested topic due to extremely weight-to-strength ratio and resistance to corrosion at elevated temperature. Quality of machined surface is presented by surface roughness, surface texture and damages of microstructure of titanium alloys. The turning parameters evaluated are cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev, depth of cut of 0.10-0.20 mm and tool grade of CVD carbide tools. The results show the trend lines of surface roughness value are higher at the initial machining and the surface texture profile has a strong correlation with the feed rate. At the machining condition of cutting speed of 95 m/min, feed rate of 0.35 mm/rev and depth of cut of 0.10 mm produced the with layer with thickness of 2.0 {mu}m.

  20. The CDC and IOTF cut points show inconsistent prevalence of underweight and overweight in chinese, indonesian, and vietnamese children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    No nationally representative data from middle and low-income countries have been analyzed to compare prevalence of underweight and overweight defined by the Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF) BMI cut points. We evaluated the consistency i...

  1. A study of the influence of cutting parameters on micromilling of steel with cubic boron nitride (CBN) tools

    NASA Astrophysics Data System (ADS)

    Klocke, Fritz; Quito, Fernando; Arntz, Kristian; Souza, Alexandre

    2009-02-01

    It has been concluded in previous studies that Cubic Boron Nitride (CBN) tools have greater wear resistance and superior tool life than other tool materials used in conventional milling, due to chemically stability at high temperatures, high abrasive wear resistance and high degree of hardness; however no research has been conducted about its performance on micro milling. Burr formation has a direct negative effect on product quality and assembly automation in micro milling, therefore adoption of machining strategies and influencing factors were investigated intending to reduce burr formation. This paper also aims at analyzing the interference of cutting parameters on micro milling with CBN tools, such as the influence of cutting speed and feed per tooth on the surface quality and tool life. These outcomes enable us to know which parameters and strategies must be used to achieve better results when micro milling steel with CBN tools.

  2. Titanium carbonitride films on cemented carbide cutting tool prepared by pulsed high energy density plasma

    NASA Astrophysics Data System (ADS)

    Feng, Wenran; Liu, Chizi; Chen, Guangliang; Zhang, Guling; Gu, Weichao; Niu, Erwu; Yang, Si-Ze

    2007-03-01

    Hard films prepared by pulsed high energy density plasma (PHEDP) are characterized by high film/substrate adhesive strength, and high wear resistance. Titanium carbonitride (TiCN) films were deposited onto YG11C (ISO G20) cemented carbide cutting tool substrates by PHEDP at room temperature. XRD, XPS, SEM, AES, etc. were adopted to analyze the phases (elements) composition, microstructure and the interface of the films, respectively. The results show that, the uniform dense films are composed of grains ranging from 70 to 90 nm. According to the AES result, there is a broad transition layer between the film and the substrate, due to the ion implantation effect of the PHEDP. The transition layer is favorable for the film/substrate adhesion.

  3. WWBT? What Would Ben Think about Killer Apps, Cutting Edges, and Tipping Points in the History of Weather and Climate?

    NASA Astrophysics Data System (ADS)

    Fleming, J. R.

    2006-12-01

    This paper examines the history of weather and climate since 1706 along three intertwined analytical axes: technology (killer apps), science (cutting edges), and social issues (tipping points). For example, Franklin's best-known killer app, the lightning rod, gains added significance when seen in light of his cutting edge contributions to the science of electricity, his lifelong promotion of useful knowledge, and the societal tipping point his work triggered in our relationship to the sky. Subsequently, other major tipping points and conceptual shifts followed the introduction of telegraphy, radio, television, digital computers, and rocketry into meteorology. Following an analysis of the career and contributions of Benjamin Franklin (1706-1790), the paper examines later historical moments and watersheds, not merely in retrospect, but from the perspective of leading participants at the time. It focuses on technologies of significant promise, especially those involving electro- magnetism, up to and including the dawn of the twenty-first century, and asks playfully, "What would Ben think?"

  4. Numerical-experimental identification of the most effective dynamic operation mode of a vibration drilling tool for improved cutting performance

    NASA Astrophysics Data System (ADS)

    Ostasevicius, V.; Ubartas, M.; Gaidys, R.; Jurenas, V.; Samper, S.; Dauksevicius, R.

    2012-11-01

    This study is concerned with application of numerical-experimental approach for characterizing dynamic behavior of the developed piezoelectrically excited vibration drilling tool with the aim to identify the most effective conditions of tool vibration mode control for improved cutting efficiency. 3D finite element model of the tool was created on the basis of an elastically fixed pre-twisted cantilever (standard twist drill). The model was experimentally verified and used together with tool vibration measurements in order to reveal rich dynamic behavior of the pre-twisted structure, representing a case of parametric vibrations with axial, torsional and transverse natural vibrations accompanied by the additional dynamic effects arising due to the coupling of axial and torsional deflections ((un)twisting). Numerical results combined with extensive data from interferometric, accelerometric, dynamometric and surface roughness measurements allowed to determine critical excitation frequencies and the corresponding vibration modes, which have the largest influence on the performance metrics of the vibration drilling process. The most favorable tool excitation conditions were established: inducing the axial mode of the vibration tool itself through tailoring of driving frequency enables to minimize magnitudes of surface roughness, cutting force and torque. Research results confirm the importance of the tool mode control in enhancing the effectiveness of vibration cutting tools from the viewpoint of structural dynamics.

  5. Cut-off point for WHOQOL-bref as a measure of quality of life of older adults

    PubMed Central

    Silva, Patrícia Aparecida Barbosa; Soares, Sônia Maria; Santos, Joseph Fabiano Guimarães; Silva, Líliam Barbosa

    2014-01-01

    OBJECTIVE To propose a cut-off for the World Health Organization Quality of Life-Bref (WHOQOL-bref) as a predictor of quality of life in older adults. METHODS Cross-sectional study with 391 older adults registered in the Northwest Health District in Belo Horizonte, MG, Southeastern Brazil, between October 8, 2010 and May 23, 2011. The older adults’ quality of life was measured using the WHOQOL-bref. The analysis was rationalized by outlining two extreme and simultaneous groups according to perceived quality of life and satisfaction with health (quality of life good/satisfactory – good or very good self-reported quality of life and being satisfied or very satisfied with health – G5; and poor/very poor quality of life – poor or very poor self-reported quality of life and feeling dissatisfied or very dissatisfied with health – G6). A Receiver-Operating Characteristic curve (ROC) was created to assess the diagnostic ability of different cut-off points of the WHOQOL-bref. RESULTS ROC curve analysis indicated a critical value 60 as the optimal cut-off point for assessing perceived quality of life and satisfaction with health. The area under the curve was 0.758, with a sensitivity of 76.8% and specificity of 63.8% for a cut-off of ≥ 60 for overall quality of life (G5) and sensitivity 95.0% and specificity of 54.4% for a cut-off of < 60 for overall quality of life (G6). CONCLUSIONS Diagnostic interpretation of the ROC curve revealed that cut-off < 60 for overall quality of life obtained excellent sensitivity and negative predictive value for tracking older adults with probable worse quality of life and dissatisfied with health. PMID:25119934

  6. Measuring physical activity in older adults: calibrating cut-points for the MotionWatch 8©

    PubMed Central

    Landry, Glenn J.; Falck, Ryan S.; Beets, Michael W.; Liu-Ambrose, Teresa

    2015-01-01

    Given the world’s aging population, the staggering economic impact of dementia, the lack of effective treatments, and the fact a cure for dementia is likely many years away – there is an urgent need to develop interventions to prevent or at least delay dementia’s progression. Thus, lifestyle approaches to promote healthy aging are an important line of scientific inquiry. Good sleep quality and physical activity (PA) are pillars of healthy aging, and as such, are an increasing focus for intervention studies aimed at promoting health and cognitive function in older adults. However, PA and sleep quality are difficult constructs to evaluate empirically. Wrist-worn actigraphy (WWA) is currently accepted as a valid objective measure of sleep quality. The MotionWatch 8© (MW8) is the latest WWA, replacing the discontinued Actiwatch 4 and Actiwatch 7. In the current study, concurrent measurement of WWA and indirect calorimetry was performed during 10 different activities of daily living for 23 healthy older adults (aged 57–80 years) to determine cut-points for sedentary and moderate-vigorous PA – using receiver operating characteristic curves – with the cut-point for light activity being the boundaries between sedentary and moderate to vigorous PA. In addition, simultaneous multi-unit reliability was determined for the MW8 using inter-class correlations. The current study is the first to validate MW8 activity count cut-points – for sedentary, light, and moderate to vigorous PA – specifically for use with healthy older adults. These cut-points provide important context for better interpretation of MW8 activity counts, and a greater understanding of what these counts mean in terms of PA. Hence, our results validate another level of analysis for researchers using the MW8 in studies aiming to examine PA and sleep quality concurrently in older adults. PMID:26379546

  7. Improved nonparametric estimation of the optimal diagnostic cut-off point associated with the Youden index under different sampling schemes.

    PubMed

    Yin, Jingjing; Samawi, Hani; Linder, Daniel

    2016-07-01

    A diagnostic cut-off point of a biomarker measurement is needed for classifying a random subject to be either diseased or healthy. However, the cut-off point is usually unknown and needs to be estimated by some optimization criteria. One important criterion is the Youden index, which has been widely adopted in practice. The Youden index, which is defined as the maximum of (sensitivity + specificity -1), directly measures the largest total diagnostic accuracy a biomarker can achieve. Therefore, it is desirable to estimate the optimal cut-off point associated with the Youden index. Sometimes, taking the actual measurements of a biomarker is very difficult and expensive, while ranking them without the actual measurement can be relatively easy. In such cases, ranked set sampling can give more precise estimation than simple random sampling, as ranked set samples are more likely to span the full range of the population. In this study, kernel density estimation is utilized to numerically solve for an estimate of the optimal cut-off point. The asymptotic distributions of the kernel estimators based on two sampling schemes are derived analytically and we prove that the estimators based on ranked set sampling are relatively more efficient than that of simple random sampling and both estimators are asymptotically unbiased. Furthermore, the asymptotic confidence intervals are derived. Intensive simulations are carried out to compare the proposed method using ranked set sampling with simple random sampling, with the proposed method outperforming simple random sampling in all cases. A real data set is analyzed for illustrating the proposed method. PMID:26756282

  8. Measuring physical activity in older adults: calibrating cut-points for the MotionWatch 8(©).

    PubMed

    Landry, Glenn J; Falck, Ryan S; Beets, Michael W; Liu-Ambrose, Teresa

    2015-01-01

    Given the world's aging population, the staggering economic impact of dementia, the lack of effective treatments, and the fact a cure for dementia is likely many years away - there is an urgent need to develop interventions to prevent or at least delay dementia's progression. Thus, lifestyle approaches to promote healthy aging are an important line of scientific inquiry. Good sleep quality and physical activity (PA) are pillars of healthy aging, and as such, are an increasing focus for intervention studies aimed at promoting health and cognitive function in older adults. However, PA and sleep quality are difficult constructs to evaluate empirically. Wrist-worn actigraphy (WWA) is currently accepted as a valid objective measure of sleep quality. The MotionWatch 8(©) (MW8) is the latest WWA, replacing the discontinued Actiwatch 4 and Actiwatch 7. In the current study, concurrent measurement of WWA and indirect calorimetry was performed during 10 different activities of daily living for 23 healthy older adults (aged 57-80 years) to determine cut-points for sedentary and moderate-vigorous PA - using receiver operating characteristic curves - with the cut-point for light activity being the boundaries between sedentary and moderate to vigorous PA. In addition, simultaneous multi-unit reliability was determined for the MW8 using inter-class correlations. The current study is the first to validate MW8 activity count cut-points - for sedentary, light, and moderate to vigorous PA - specifically for use with healthy older adults. These cut-points provide important context for better interpretation of MW8 activity counts, and a greater understanding of what these counts mean in terms of PA. Hence, our results validate another level of analysis for researchers using the MW8 in studies aiming to examine PA and sleep quality concurrently in older adults. PMID:26379546

  9. Technical Manual for the Conceptual Learning and Development Assessment Series II: Cutting Tool. Technical Report No. 435. Reprinted December 1977.

    ERIC Educational Resources Information Center

    DiLuzio, Geneva J.; And Others

    This document accompanies Conceptual Learning and Development Assessment Series II: Cutting Tool, a test constructed to chart the conceptual development of individuals. As a technical manual, it contains information on the rationale, development, standardization, and reliability of the test, as well as essential information and statistical data…

  10. Teacher Education Budget Cuts in Romania and the US: Points of Contrast and Comparison

    ERIC Educational Resources Information Center

    Ives, B.; Alama, M.; Mosora, C. L.

    2013-01-01

    Background: Budgets for teacher education programmes have been substantially reduced as a result of the global economic crisis. Purpose: The purpose of this study was to compare the teacher education budget cutting processes and procedures for universities in Romania versus one university in the United States. Sample: The data were collected from…

  11. Insulin sensitivity indices: a proposal of cut-off points for simple identification of insulin-resistant subjects.

    PubMed

    Radikova, Z; Koska, J; Huckova, M; Ksinantova, L; Imrich, R; Vigas, M; Trnovec, T; Langer, P; Sebokova, E; Klimes, I

    2006-05-01

    Demanding measurement of insulin sensitivity using clamp methods does not simplify the identification of insulin resistant subjects in the general population. Other approaches such as fasting- or oral glucose tolerance test-derived insulin sensitivity indices were proposed and validated with the euglycemic clamp. Nevertheless, a lack of reference values for these indices prevents their wider use in epidemiological studies and clinical practice. The aim of our study was therefore to define the cut-off points of insulin resistance indices as well as the ranges of the most frequently obtained values for selected indices. A standard 75 g oral glucose tolerance test was carried out in 1156 subjects from a Caucasian rural population with no previous evidence of diabetes or other dysglycemias. Insulin resistance/sensitivity indices (HOMA-IR, HOMA-IR2, ISI Cederholm, and ISI Matsuda) were calculated. The 75th percentile value as the cut-off point to define IR corresponded with a HOMA-IR of 2.29, a HOMA-IR2 of 1.21, a 25th percentile for ISI Cederholm, and ISI Matsuda of 57 and 5.0, respectively. For the first time, the cut-off points for selected indices and their most frequently obtained values were established for groups of subjects as defined by glucose homeostasis and BMI. Thus, insulin-resistant subjects can be identified using this simple approach. PMID:16804799

  12. Photoluminescence as a tool for characterizing point defects in semiconductors

    NASA Astrophysics Data System (ADS)

    Reshchikov, Michael

    2012-02-01

    Photoluminescence is one of the most powerful tools used to study optically-active point defects in semiconductors, especially in wide-bandgap materials. Gallium nitride (GaN) and zinc oxide (ZnO) have attracted considerable attention in the last two decades due to their prospects in optoelectronics applications, including blue and ultraviolet light-emitting devices. However, in spite of many years of extensive studies and a great number of publications on photoluminescence from GaN and ZnO, only a few defect-related luminescence bands are reliably identified. Among them are the Zn-related blue band in GaN, Cu-related green band and Li-related orange band in ZnO. Numerous suggestions for the identification of other luminescence bands, such as the yellow band in GaN, or green and yellow bands in ZnO, do not stand up under scrutiny. In these conditions, it is important to classify the defect-related luminescence bands and find their unique characteristics. In this presentation, we will review the origin of the major luminescence bands in GaN and ZnO. Through simulations of the temperature and excitation intensity dependences of photoluminescence and by employing phenomenological models we are able to obtain important characteristics of point defects such as carrier capture cross-sections for defects, concentrations of defects, and their charge states. These models are also used to find the absolute internal quantum efficiency of photoluminescence and obtain information about nonradiative defects. Results from photoluminescence measurements will be compared with results of the first-principle calculations, as well as with the experimental data obtained by other techniques such as positron annihilation spectroscopy, deep-level transient spectroscopy, and secondary ion mass spectrometry.

  13. Hollow needle used to cut metal honeycomb structures

    NASA Technical Reports Server (NTRS)

    Gregg, E. A.

    1966-01-01

    Hollow needle tool cuts metal honeycomb structures without damaging adjacent material. The hollow needle combines an electrostatic discharge and a stream of oxygen at a common point to effect rapid, accurate metal cutting. The tool design can be varied to use the hollow needle principle for cutting a variety of shapes.

  14. Extent of microcytic anemia among children in a low-income, peri-urban community in the Dominican Republic using different cut-points.

    PubMed

    McLennan, John D; Steele, MacGregor

    2015-04-01

    Response to anemia in low-resource settings may entail presumptive iron treatment for those with Hemoglobin (Hb) levels falling below certain cut points. This study aimed to inform an anemia screening and treatment service in a low-income community in the Dominican Republic by determining (i) the prevalence of anemia in young children attending this service using different Hb cut points and (ii) the extent of microcytosis using different recommended cut points for the mean corpuscular volume (MCV). Using the WHO recommended cut point of <11.0 g/dl, 69.9% of 292 children would be classified as anemic, while using a more conservative cut point, <10.0 g/dl, 34.6% would be identified. Depending on the Hb cut point and which of two age-based MCV cut points are used, the prevalence of microcytosis within the anemic subsamples ranged from 23.5% to 80.2%. With increasing availability of complete blood counts in low resource settings (vs. Hb only), more sophisticated management algorithms are necessary to guide primary care efforts. PMID:25505156

  15. Microstructural characterization of WC-TiC-Co cutting tools during high-speed machining of P20 mold steel

    SciTech Connect

    Farhat, Z.N

    2003-10-15

    The wear behavior of tungsten carbide (WC)-TiC-Co cutting tools during cutting P20 tool steel was investigated. Orthogonal cutting tests were performed on a CNC lathe using five speeds, namely, 60, 120, 240, 380 and 600 m/min. Wear, as the width of the wear land, was monitored at five time intervals. Wear characterization of the rake and the flank surfaces as well as the collected chips was performed using scanning electron microscopy (SEM), backscattered electron imaging and energy-dispersive X-ray analysis (EDX). Microhardness of collected chips was also performed to monitor strain hardening effects during cutting. Two dominant wear mechanisms were identified: at high speed (380-600 m/min), wear was found to occur by a melt wear mechanism; at low speed (60-120 m/min), adhesion (built-up edge) followed by delamination was found to be the cause of wear damage. It was also found that deformation in the chips occurred by localized shear deformation.

  16. Prescribed fire and cutting as tools for reducing woody plant succession in a created salt marsh

    USGS Publications Warehouse

    Owens, A.B.; Proffitt, C.E.; Grace, J.B.

    2007-01-01

    This paper reports on efforts to reduce woody successional growth by the native shrub Iva frutescens L. in a created salt marsh by using prescribed fire and cutting. Experimental treatments included a winter burn, cutting plants at ground level, and a combination burn-and-cut treatment, with replicate plots of each. Iva frutescens proved to be extremely hardy, with zero mortality following the cutting, burning, or combination treatment; similar levels of regrowth were observed for all treatments. Individual shrub response, however, was found to be related to initial plant size, ground water level and salinity, and two fire characteristics (total heating >60??C and total heat index >60??C). Fire severity, sediment nutrient concentrations, and other abiotic factors had no observable effects. ?? 2007 Springer Science+Business Media B.V.

  17. Thermo-radiative and optical properties of a cutting tool based on polycrystalline cubic boron nitride (PCBN)

    NASA Astrophysics Data System (ADS)

    González de Arrieta, I.; Echániz, T.; Pérez-Sáez, R. B.; Tello, M. J.

    2016-04-01

    The normal spectral emissivity of a cutting tool based on polycrystalline cubic boron nitride (PCBN) between 400 °C and 1000 °C has been measured. Its shape shows significant differences with respect to that of pure cubic boron nitride (c-BN). Therefore, while the reflectance spectrum of pure c-BN can be fitted to a Lorentz model for linear dielectrics, the reflectance spectrum of the cutting tool (calculated from the emissivity using Kirchhoff’s laws) requires a combination of a four-parameter Kurosawa model with a double-damping Drude one. A detailed study of the dependence of the emissivity spectrum with temperature is also performed. The experimental data of this paper is required for accurate temperature measurements with radiation thermometers in machining processes.

  18. An optimal cut-off point for the calving interval may be used as an indicator of bovine abortions.

    PubMed

    Bronner, Anne; Morignat, Eric; Gay, Emilie; Calavas, Didier

    2015-10-01

    The bovine abortion surveillance system in France aims to detect as early as possible any resurgence of bovine brucellosis, a disease of which the country has been declared free since 2005. It relies on the mandatory notification and testing of each aborting cow, but under-reporting is high. This research uses a new and simple approach which considers the calving interval (CI) as a "diagnostic test" to determine optimal cut-off point c and estimate diagnostic performance of the CI to identify aborting cows, and herds with multiple abortions (i.e. three or more aborting cows per calving season). The period between two artificial inseminations (AI) was considered as a "gold standard". During the 2006-2010 calving seasons, the mean optimal CI cut-off point for identifying aborting cows was 691 days for dairy cows and 703 days for beef cows. Depending on the calving season, production type and scale at which c was computed (individual or herd), the average sensitivity of the CI varied from 42.6% to 64.4%; its average specificity from 96.7% to 99.7%; its average positive predictive value from 27.6% to 65.4%; and its average negative predictive value from 98.7% to 99.8%. When applied to the French bovine population as a whole, this indicator identified 2-3% of cows suspected to have aborted, and 10-15% of herds suspected of multiple abortions. The optimal cut-off point and CI performance were consistent over calving seasons. By applying an optimal CI cut-off point to the cattle demographics database, it becomes possible to identify herds with multiple abortions, carry out retrospective investigations to find the cause of these abortions and monitor a posteriori compliance of farmers with their obligation to report abortions for brucellosis surveillance needs. Therefore, the CI could be used as an indicator of abortions to help improve the current mandatory notification surveillance system. PMID:26318526

  19. An immunoinhibition approach to overcome the impact of pre-existing antibodies on cut point establishment for immunogenicity assessment of moxetumomab pasudotox.

    PubMed

    Schneider, Amy K; Vainshtein, Inna; Roskos, Lorin K; Chavez, Carlos; Sun, Bo; Liang, Meina

    2016-08-01

    Immunogenicity can impact PK, PD, efficacy and safety of biopharmaceuticals, and is often evaluated as a secondary objective in clinical studies. Methods to detect anti-drug antibodies (ADA) and neutralizing ADA (NAb) are semi-quantitative and utilize cut points to determine positive or negative samples. Assay cut points are established by the statistical analysis of treatment-naïve subject specimens that are assumed ADA and NAb-negative. Pre-existing antibodies to various biopharmaceuticals have been observed in treatment-naïve subjects and may artificially elevate the cut point, resulting in compromised assay sensitivities, inaccuracy in immunogenicity reporting and ultimately misleading assessment of the impact of immunogenicity on clinical outcomes. Although several approaches such as removal of pre-existing antibody samples or increasing the sample dilution could be used for cut point establishment to mitigate impact of pre-existing antibodies, they each have limitations, especially when a high prevalence of pre-existing antibodies is observed. Here we describe an innovative approach used to establish cut points for ADA and NAb assays of moxetumomab pasudotox (moxetumomab), a recombinant anti-CD22 immunotoxin, to which a high prevalence of pre-existing antibodies was observed. In order to overcome the challenges associated with this high prevalence and prevent establishment of an artificially elevated cut point, we developed an immunoinhibition approach that allowed generation of pseudo ADA and NAb-negative populations for cut point determination. Immunoinhibition was performed by adding excess moxetumomab (for ADA) or a non-CD22 binding PE38-containing immunotoxin, CAT-5001 (for NAb), to treatment-naive samples prior to evaluating samples for cut point establishment. This approach successfully eliminated pre-existing antibody activity in treatment-naive samples, enabling establishment of more accurate ADA and NAb assay cut points. A comparative analysis of

  20. Response Surface Methodology Approach on Effect of Cutting Parameter on Tool Wear during End Milling of High Thermal Conductivity Steel -150 (HTCS-150)

    NASA Astrophysics Data System (ADS)

    Mohd Hadzley, A. B.; Mohd Azahar, W. M. Y. Wan; Izamshah, R.; Mohd Shahir, K.; Mohd Amran, A.; Anis Afuza, A.

    2016-02-01

    This paper presents a study of development the tool life's mathematical model during the milling process on High Thermal Conductivity Steel 150 (HTCS-150) 56 HRC. Using response surface methodology, the mathematical models for tool life have been developed in terms of cutting speed, feed rate and depth of cut. Box-Behnken techniques is a part of Response Surface Methodology (RSM) has been used to carry out the work plan to predict, the tool wear and generate the numerical equation in relation to independent variable parameters by Design Expert software. Dry milling experiments were conducted by using two levels of cutting speed, feed rate and depth of cut. In this study, the variable for the cutting speed, feed rate and depth of cut were in the range of 484-553 m/min, 0.31-0.36 mm/tooth, and 0.1-0.5 mm, width of cut is constantly 0.01mm per passes. The tool wear was measured using tool maker microscope. The effect of input factors that on the responds were identified by using mean of ANOVA. The responds of tool wear then simultaneously optimized. The validation of the test reveals the model accuracy 5% and low tool wear under same experimental condition.

  1. P04.10PREDICTIVE VALUE OF MGMT PROMOTER METHYLATION QUANTITATIVE ASSESSMENT IN GLIOBLASTOMA, WHICH OPTIMAL CUT-POINT?

    PubMed Central

    de Saint-Denis, T.; Lerhun, E.; Ramirez, C.; Devos, P.; Maurage, C.A.; Dubois, F.; Reyns, N.; Escande, F.

    2014-01-01

    BACKGROUND: The methylation in the promoter region of the MGMT gene encoding the DNA repair protein O6-methyl guanine-DNA methyl transferase is a predictive marker for benefit from alkylating agent therapy and a prognostic factor in glioblastoma. Pyrosequencing-based assessement of MGMT promoter status is of particularly interest, but analytical methods and cut-points may varied from one center to another. We intend to establish a correlation between quantitative methylation of MGMT promoter values and overall survival (OS) or progression-free survival (PFS). METHODS: The clinical and biological data of 159 newly diagnosed glioblastoma recruited in Lille University Hospital between 2008 and 2011 were retrospectively collected. For the patients, the methylation status has been assessed by pyrosequencing on 5 CpG islands. Statistical analyses were performed using SAS software V9.3. RESULTS: Median age of the patients was 61 years. Sixty three patients were male. Of 159 patients, 156 underwent a surgery (40,4% of complete resection), 3 patients were diagnosed only by biopsies. 123 received concomitant radiotherapy and temozolomide and adjuvant temozolomide. The median PFS and the median OS were 9,9 and 15,9. The most significant cut-off methylation determined on 5 sites mean methylaion value was 12% for both predictive and pronostic evaluations. Site 1 methylation status was the best predictive value for both PFS and OS compared to the other CpG islands. On this site 1, a >3% methylation status was a significant predictive factor for reponse to standard treatment for PFS and a >25% site 1 methylation status was a strong pronostic factor for 2 years survival (OS) (47%). CONCLUSIONS: Even a low MGMT methylation (>3%) status on selected CpG site can already be a predictive factor for response to treatment in glioblastoma and allow us to reduce the cut-off values. Highest methylations status are correlated with the longest overall survival and therefore confirm the

  2. Applying the self-organization feature map (SOM) algorithm to AE-based tool wear monitoring in micro-cutting

    NASA Astrophysics Data System (ADS)

    Yen, Chia-Liang; Lu, Ming-Chyuan; Chen, Jau-Liang

    2013-01-01

    This study applies a self-organization feature map (SOM) neural network to acoustic emission (AE) signal-based tool wear monitoring for a micro-milling process. An experiment was set up to collect the signal during cutting for the system development and performance analysis. The AE signal generated on the workpiece was first transformed to the frequency domain by Fast Fourier transformation (FFT), followed by feature extraction processing using the SOM algorithm. The performance verification in this study adopts a learning vector quantification (LVQ) network to evaluate the effects of the SOM algorithm on the classification performance for tool wear monitoring. To investigate the improvement achieved by the SOM algorithms, this study also investigates cases applying only the LVQ classifier and based on the class mean scatter feature selection (CMSFS) criterion and LVQ. Results show that accurate classification of the tool wear can be obtained by properly selecting features closely related to the tool wear based on the CMSFS and frequency resolution of spectral features. However, the SOM algorithms provide a more reliable methodology of reducing the effect on the system performance contributed by noise or variations in the cutting system.

  3. Steam as a pre-plant soil disinfestant tool in California cut flower production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide (MB) has been widely used in California cut flower production for effective control of a broad range of soil pests including plant pathogens and weeds. However, MB has been classified as an ozone depleting substance, and its availability to growers is limited according to the Montreal...

  4. Effect of microscale texture on cutting performance of WC/Co-based TiAlN coated tools under different lubrication conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Kedong; Deng, Jianxin; Xing, Youqiang; Li, Shipeng; Gao, Huanhuan

    2015-01-01

    Commonly known the severe friction between the tool and chip affects the tool life and the quality of the machined surfaces. Introducing a lubricant into the tool-chip interface can be used to alleviate the friction, the effectiveness of which may be improved by surface texturing of the tools. Thus, surface textures were fabricated using laser on the rake of the cemented carbide (WC/Co) inserts, then TiAlN films were coated on the textured tools. The effect of the textures on the cutting performance was investigated using the textured coated tools and conventional coated tools in cutting AISI 1045 hardened steel tests. Two batches of cutting tests were carried out, in regimes of full and starved lubrication. The machining performance was assessed in terms of the cutting forces, friction coefficient at the tool-chip interface, surface roughness of machined workpiece and tool wear on the rake face. Results show that the cutting performance of textured tools was enhanced, especially under the full lubrication condition.

  5. A Hard Sell: Factors Influencing the Interwar Adoption of Tungsten Carbide Cutting Tools in Germany, Britain, and the United States.

    PubMed

    Giffard, Hermione

    2015-10-01

    Cemented tungsten carbide cutting tools-virtually unknown to historians-came on the market in the late 1920s. Although existing literature alleges that their adoption was rapid and universal, contemporary data indicate that the rate of adoption in fact took many decades and varied greatly between the world's three leading industrialized economies of the time: Germany, England, and the United States. This article suggests that the explanation lies in differing national environments for innovation in the interwar period. It looks at many features that influence adoption by users and argues that the feature emphasized in the literature, increased cutting speed, was not the primary consideration behind adoption, but rather metal shortages. It thereby casts doubt on what measures of national productivity show. The case raises important questions about the use of production efficiency to make international comparisons and about the role of patent monopolies in introducing production innovations. PMID:26593713

  6. Active control of residual tool marks for freeform optics functionalization by novel biaxial servo assisted fly cutting.

    PubMed

    Zhu, Zhiwei; To, Suet; Zhang, Shaojian

    2015-09-01

    The inherent residual tool marks (RTM) with particular patterns highly affect optical functions of the generated freeform optics in fast tool servo or slow tool servo (FTS/STS) diamond turning. In the present study, a novel biaxial servo assisted fly cutting (BSFC) method is developed for flexible control of the RTM to be a functional micro/nanotexture in freeform optics generation, which is generally hard to achieve in FTS/STS diamond turning. In the BSFC system, biaxial servo motions along the z-axis and side-feeding directions are mainly adopted for primary surface generation and RTM control, respectively. Active control of the RTM from the two aspects, namely, undesired effect elimination or effective functionalization, are experimentally demonstrated by fabricating a typical F-theta freeform surface with scattering homogenization and two functional microstructures with imposition of secondary phase gratings integrating both reflective and diffractive functions. PMID:26368889

  7. Discrete element thermomechanical modelling of rock cutting with valuation of tool wear

    NASA Astrophysics Data System (ADS)

    Rojek, Jerzy

    2014-05-01

    The paper presents a thermomechanical discrete element model of rock cutting process. The thermomechanical formulation of the discrete element method considers mechanical and thermal phenomena and their reciprocal influence. The thermal model developed for transient heat conduction problems takes into account conductive heat transfer at the contact between particles and convection on the free surface. The thermal and mechanical problems are coupled by consideration of: (1) heat generated due to friction which is calculated in the mechanical problem and passed to the thermal solution, (2) influence of thermal expansion on mechanical interaction between particles. Estimation of temperature dependent wear has been included into the contact model. The coupled problem is solved using the staggered scheme.The thermomechanical algorithm has been implemented in a discrete element program and applied to simulation of rock cutting with single pick of a dredge cutter head. Numerical results confirm good performance of the developed algorithm.

  8. Defining natural species of bacteria: clear-cut genomic boundaries revealed by a turning point in nucleotide sequence divergence

    PubMed Central

    2013-01-01

    Background Bacteria are currently classified into arbitrary species, but whether they actually exist as discrete natural species was unclear. To reveal genomic features that may unambiguously group bacteria into discrete genetic clusters, we carried out systematic genomic comparisons among representative bacteria. Results We found that bacteria of Salmonella formed tight phylogenetic clusters separated by various genetic distances: whereas over 90% of the approximately four thousand shared genes had completely identical sequences among strains of the same lineage, the percentages dropped sharply to below 50% across the lineages, demonstrating the existence of clear-cut genetic boundaries by a steep turning point in nucleotide sequence divergence. Recombination assays supported the genetic boundary hypothesis, suggesting that genetic barriers had been formed between bacteria of even very closely related lineages. We found similar situations in bacteria of Yersinia and Staphylococcus. Conclusions Bacteria are genetically isolated into discrete clusters equivalent to natural species. PMID:23865772

  9. Effects of Varying Epoch Lengths, Wear Time Algorithms, and Activity Cut-Points on Estimates of Child Sedentary Behavior and Physical Activity from Accelerometer Data

    PubMed Central

    Banda, Jorge A.; Haydel, K. Farish; Davila, Tania; Desai, Manisha; Haskell, William L.; Matheson, Donna; Robinson, Thomas N.

    2016-01-01

    Objective To examine the effects of accelerometer epoch lengths, wear time (WT) algorithms, and activity cut-points on estimates of WT, sedentary behavior (SB), and physical activity (PA). Methods 268 7–11 year-olds with BMI ≥ 85th percentile for age and sex wore accelerometers on their right hips for 4–7 days. Data were processed and analyzed at epoch lengths of 1-, 5-, 10-, 15-, 30-, and 60-seconds. For each epoch length, WT minutes/day was determined using three common WT algorithms, and minutes/day and percent time spent in SB, light (LPA), moderate (MPA), and vigorous (VPA) PA were determined using five common activity cut-points. ANOVA tested differences in WT, SB, LPA, MPA, VPA, and MVPA when using the different epoch lengths, WT algorithms, and activity cut-points. Results WT minutes/day varied significantly by epoch length when using the NHANES WT algorithm (p < .0001), but did not vary significantly by epoch length when using the ≥ 20 minute consecutive zero or Choi WT algorithms. Minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA varied significantly by epoch length for all sets of activity cut-points tested with all three WT algorithms (all p < .0001). Across all epoch lengths, minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA also varied significantly across all sets of activity cut-points with all three WT algorithms (all p < .0001). Conclusions The common practice of converting WT algorithms and activity cut-point definitions to match different epoch lengths may introduce significant errors. Estimates of SB and PA from studies that process and analyze data using different epoch lengths, WT algorithms, and/or activity cut-points are not comparable, potentially leading to very different results, interpretations, and conclusions, misleading research and public policy. PMID:26938240

  10. X-Lase CoreScriber, Picosecond Fiber Laser Tool for High-Precision Scribing and Cutting of Transparent Materials

    NASA Astrophysics Data System (ADS)

    Kivistö, S.; Amberla, T.; Konnunaho, T.; Kangastupa, J.; Sillanpää, J.

    We have developed various industrial transparent material scribing processes and a laser tool, picosecond MHz-range all- fiber laser X-Lase CoreScriber. The remarkably high peak power, exceptionally good beam quality, and integrability of the X-Lase CoreScriber combined with high achievable material processing speeds provide tempting solutions for high- precision glass processing. Here presented sapphire and Gorilla glass dicing processes are based on transparent material internal modification with short and intense high repetition rate ps-laser pulses. Increased processing speeds and cutting qualities in comparison to other conventional processing methods are presented.

  11. Screen Twice, Cut Once: Assessing the Predictive Validity of Teacher Selection Tools. Working Paper 120

    ERIC Educational Resources Information Center

    Goldhaber, Dan; Grout, Cyrus; Huntington-Klein, Nick

    2014-01-01

    Evidence suggests that teacher hiring in public schools is ad hoc and often fails to result in good selection among applicants. Some districts use structured selection instruments in the hiring process, but we know little about the efficacy of such tools. In this paper, we evaluate the ability of applicant selection tools used by the Spokane…

  12. The influence of tool path strategies on cutting force and surface texture during ball end milling of low curvature convex surfaces.

    PubMed

    Shajari, Shaghayegh; Sadeghi, Mohammad Hossein; Hassanpour, Hamed

    2014-01-01

    Advancement in machining technology of curved surfaces for various engineering applications is increasing. Various methodologies and computer tools have been developed by the manufacturers to improve efficiency of freeform surface machining. Selection of the right sets of cutter path strategies and appropriate cutting conditions is extremely important in ensuring high productivity rate, meeting the better quality level, and lower cutting forces. In this paper, cutting force as a new decision criterion for the best selection of tool paths on convex surfaces is presented. Therefore, this work aims at studying and analyzing different finishing strategies to assess their influence on surface texture, cutting forces, and machining time. Design and analysis of experiments are performed by means of Taguchi technique and analysis of variance. In addition, the significant parameters affecting the cutting force in each strategy are introduced. Machining strategies employed include raster, 3D-offset, radial, and spiral. The cutting parameters were feed rate, cutting speed, and step over. The experiments were carried out on low curvature convex surfaces of stainless steel 1.4903. The conclusion is that radial strategy provokes the best surface texture and the lowest cutting forces and spiral strategy signifies the worst surface texture and the highest cutting forces. PMID:24701163

  13. The Influence of Tool Path Strategies on Cutting Force and Surface Texture during Ball End Milling of Low Curvature Convex Surfaces

    PubMed Central

    Sadeghi, Mohammad Hossein; Hassanpour, Hamed

    2014-01-01

    Advancement in machining technology of curved surfaces for various engineering applications is increasing. Various methodologies and computer tools have been developed by the manufacturers to improve efficiency of freeform surface machining. Selection of the right sets of cutter path strategies and appropriate cutting conditions is extremely important in ensuring high productivity rate, meeting the better quality level, and lower cutting forces. In this paper, cutting force as a new decision criterion for the best selection of tool paths on convex surfaces is presented. Therefore, this work aims at studying and analyzing different finishing strategies to assess their influence on surface texture, cutting forces, and machining time. Design and analysis of experiments are performed by means of Taguchi technique and analysis of variance. In addition, the significant parameters affecting the cutting force in each strategy are introduced. Machining strategies employed include raster, 3D-offset, radial, and spiral. The cutting parameters were feed rate, cutting speed, and step over. The experiments were carried out on low curvature convex surfaces of stainless steel 1.4903. The conclusion is that radial strategy provokes the best surface texture and the lowest cutting forces and spiral strategy signifies the worst surface texture and the highest cutting forces. PMID:24701163

  14. Evaluating Gaze-Based Interface Tools to Facilitate Point-and-Select Tasks with Small Targets

    ERIC Educational Resources Information Center

    Skovsgaard, Henrik; Mateo, Julio C.; Hansen, John Paulin

    2011-01-01

    Gaze interaction affords hands-free control of computers. Pointing to and selecting small targets using gaze alone is difficult because of the limited accuracy of gaze pointing. This is the first experimental comparison of gaze-based interface tools for small-target (e.g. less than 12 x 12 pixels) point-and-select tasks. We conducted two…

  15. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    NASA Astrophysics Data System (ADS)

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  16. The Effect of the Gas Inlet on the Fluid Field during Fabricating Hfcvd Diamond-Coated Cutting Tools

    NASA Astrophysics Data System (ADS)

    Shen, Bin; Chen, Sulin; Cheng, Lei; Sun, Fanghong

    2014-07-01

    In the present study, the fluid field in a process of fabricating diamond coated cutting tools using the hot filament chemical vapor deposition (HFCVD) method is investigated using the finite volume method (FVM), in which the effects of the inlet height, gas initial velocity, inlet radius and arrangement are illustrated in terms of the gas velocity magnitude and vector distribution near the filaments and the flute surface of cutting tools. In the simulations, the coupling effect of the temperature and the gas field is also considered by simultaneously calculating the temperature distribution. The simulation results suggest that either shortening the distance between the gas inlet and filaments, or increasing the gas initial velocity is helpful for the reactive gas arriving at filaments surface and being dissociated. Furthermore, increasing the inlet area is able to significantly increase the velocity of gas field around the filaments, as well as produce a much more uniform gas velocity field. Based on this conclusion, two novel multi-inlets setups are proposed to further improve the generated gas field and the simulation results show that the most superior gas field can be achieved with the one including 8 larger central inlets and 24 smaller outskirt inlets. Finally, an actual deposition experiment is carried out and its result indicates that adopting the optimized such inlet arrangement could generate a highly uniform and homogeneous growth environment on whole deposition area.

  17. 13C urea breath test for Helicobacter pylori: Determination of the optimal cut-off point in a Canadian community population

    PubMed Central

    Mauro, Marina; Radovic, Vladimir; Zhou, Pengfei; Wolfe, Melanie; Kamath, Markad; Bercik, Premsyl; Croitoru, Ken; Armstrong, David

    2006-01-01

    AIM: To determine the test characteristics and the optimal cut-off point for the 13C urea breath test (13C UBT) in a Canadian community laboratory setting. METHODS: Of 2232 patients (mean age ± SD: 51±21 years, 56% female) who completed a 13C UBT, 1209 were tested to evaluate the primary diagnosis of Helicobacter pylori infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the 13C UBT against histology and microbiology using the calculated cut-off point. RESULTS: The calculated cut-off points were 3.09 δ‰ for the whole study population (n=2232), 3.09 δ‰ for the diagnosis group (n=1209) and 2.88 δ‰ for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 δ‰, the risk of false-positive and false-negative results was lower than 2.3%. The 13C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active H pylori infection. CONCLUSIONS: The 13C UBT is an accurate, noninvasive test for the diagnosis of H pylori infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cutoff point of 3.0 δ‰ for the 13C UBT when used in a large Canadian community population according to a standard protocol. PMID:17171195

  18. Tool grinding machine

    DOEpatents

    Dial, Sr., Charles E.

    1980-01-01

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thickness may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  19. Improved tool grinding machine

    DOEpatents

    Dial, C.E. Sr.

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thicknesses may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  20. MALDI mass spectrometry imaging: A cutting-edge tool for fundamental and clinical histopathology.

    PubMed

    Longuespée, Rémi; Casadonte, Rita; Kriegsmann, Mark; Pottier, Charles; Picard de Muller, Gaël; Delvenne, Philippe; Kriegsmann, Jörg; De Pauw, Edwin

    2016-07-01

    Histopathological diagnoses have been done in the last century based on hematoxylin and eosin staining. These methods were complemented by histochemistry, electron microscopy, immunohistochemistry (IHC), and molecular techniques. Mass spectrometry (MS) methods allow the thorough examination of various biocompounds in extracts and tissue sections. Today, mass spectrometry imaging (MSI), and especially matrix-assisted laser desorption ionization (MALDI) imaging links classical histology and molecular analyses. Direct mapping is a major advantage of the combination of molecular profiling and imaging. MSI can be considered as a cutting edge approach for molecular detection of proteins, peptides, carbohydrates, lipids, and small molecules in tissues. This review covers the detection of various biomolecules in histopathological sections by MSI. Proteomic methods will be introduced into clinical histopathology within the next few years. PMID:27188927

  1. Tool for cutting locking cups from guide tube mounting screws in a nuclear reactor

    SciTech Connect

    Nee, J.D.; Hahn, J.J.

    1987-09-01

    This patent describes an apparatus for freeing a socket-head screw from a locking cup therefor in a reactor cavity, wherein the locking cup includes a fixed cylindrical side wall encircling the side surface of the screw head and an annular end wall overlying the outer end surface of the screw head. The apparatus consists of: frame means, cylindrical cutter means having a longitudinal axis and having a frustoconical cutting surface with an inner diameter less than the inner diameter of the locking cup side wall and with an outer diameter greater than the outer diameter of the locking cup side wall, and drive means carried by the frame means and coupled to the cutter means for effecting rotation thereof about the axis, the rotating cutter means are operable for severing the locking cup end wall from the locking cup side wall at the junction therebetween when the cutter means is moved against the locking cup substantially coaxially therewith.

  2. Ream-while-drilling tool cuts costs of three Venezuelan wells

    SciTech Connect

    Rothe, J.R.; Carre C., L.J.; Portillo, R.; Leal, M.

    1997-01-13

    A new tool that permits simultaneous drilling and hole enlargement reduced drilling costs by more than $780,000 on three wells in eastern Venezuela. The new ream-while-drilling (RWD) tool was used for the first time in Venezuela in Lagoven SA`s exploratory well PTL-4X, in which an influx of formation gas in the top hole required an unexpected alteration of the original casing program. The modification of the casing program necessitated underreaming for the first time in the new field, located in the State of Monagas. On the basis of eliminating the additional 36 days of rig time and other expenses associated with the conventional reaming undertaken in similar wells in the area, the one-pass operation saved an estimated $634,834 in drilling costs. Because of the success of the PTL-4X operation, Corpoven SA subsequently used the RWD system in the Mulata field, where offset wells traditionally required an average of 1,973 ft of underreaming. One tool successfully drilled and reamed two wells and remained in a condition suitable for reuse. Corpoven ran the tool under a rental agreement and saved $146,782, when compared to three Mulata offsets. The paper discusses reaming experience, RWD tool design, and economic analysis.

  3. Multiscale Analysis of Surface Topography from Single Point Incremental Forming using an Acetal Tool

    NASA Astrophysics Data System (ADS)

    Ham, M.; Powers, B. M.; Loiselle, J.

    2014-03-01

    Single point incremental forming (SPIF) is a sheet metal manufacturing process that forms a part by incrementally applying point loads to the material to achieve the desired deformations and final part geometry. This paper investigates the differences in surface topography between a carbide tool and an acetal-tipped tool. Area-scale analysis is performed on the confocal areal surface measurements per ASME B46. The objective of this paper is to determine at which scales surfaces formed by two different tool materials can be differentiated. It is found that the surfaces in contact with the acetal forming tool have greater relative areas at all scales greater than 5 × 104 μm2 than the surfaces in contact with the carbide tools. The surfaces not in contact with the tools during forming, also referred to as the free surface, are unaffected by the tool material.

  4. The effect of tool geometry on subsurface damage and material removal in nanometric cutting single-crystal silicon by a molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Dai, Houfu; Chen, Genyu; Fang, Qihong; Yin, Jiu

    2016-09-01

    Molecular dynamics is employed to investigate the nanoscale cutting process of monocrystalline silicon with diamond tool. Materials removal behavior of workpiece through diamond cutting is studied. The effects of tool geometry on the deformation of material including rake angle, clearance angle and edge radius were carefully explored by analyzing the phase transformation, chips, hydrostatic stress, shear stress and workpiece deformation. The investigation shows that a positive rake angle tip, a larger clearance angle tip or a small edge radius tip would result in a smaller cutting force, a better subsurface and a larger chipping volume. Moreover, a bigger negative rake angle tip cutting has a larger hydrostatic stress and shear stress. However, a positive rake angle tip cutting has a larger average friction coefficient than a negative rake angle tip cutting, which means that negative rake angle tip cutting experiences a lower resistance rate. It is also found that a tip with positive rake angle or smaller edge radius will improve the smoothness of a ground surface. In addition, a bigger clearance angle tip cutting generates a lower temperature in workpiece.

  5. Picosecond laser fabrication of micro cutting tool geometries on polycrystalline diamond composites using a high-numerical aperture micro scanning system

    NASA Astrophysics Data System (ADS)

    Eberle, Gregory; Dold, Claus; Wegener, Konrad

    2015-03-01

    The generation of microsized components found in LEDs, watches, molds as well as other types of micromechanics and microelectronics require a corresponding micro cutting tool in order to be manufactured, typically by milling or turning. Micro cutting tools are made of cemented tungsten carbide and are conventionally fabricated either by electrical discharge machining (EDM) or by grinding. An alternative method is proposed through a laser-based solution operating in the picosecond pulse duration whereby the beam is deflected using a modified galvanometer-driven micro scanning system exhibiting a high numerical aperture. A micro cutting tool material which cannot be easily processed using conventional methods is investigated, which is a fine grain polycrystalline diamond composite (PCD). The generation of various micro cutting tool relevant geometries, such as chip breakers and cutting edges, are demonstrated. The generated geometries are subsequently evaluated using scanning electron microscopy (SEM) and quality is measured in terms of surface roughness and cutting edge sharpness. Additionally, two processing strategies in which the laser beam processes tangentially and orthogonally are compared in terms of quality.

  6. Laser Physical Vapor Deposition of Nanocrystalline Boron Carbide Films to Enhance Cutting Tool Performance

    SciTech Connect

    Jagannadham, K.; Watkins, Thomas R; Lance, Michael J; Riester, Laura; Lemaster, Robert A

    2009-01-01

    Laser physical vapor deposition was used to deposit thin films of boron carbide on Si (100) and WC-Co substrates at 550 C under different pressures of methane atmosphere. Grazing incidence X-ray diffraction was used to identify a boron carbide phase, which exhibited weak peaks. The presence of particulates in the size range of 50 nm-3 {micro}m embedded in an amorphous matrix was observed by scanning electron microscopy. Raman spectroscopy indicated that as methane partial pressure was increased during deposition, the amount of disorder with the boron carbide structure also increased. Also, the nanoindentation hardness decreased, while the coefficient of friction and scratch adhesion strength increased. These effects are attributed to an increase in amorphous phase/disorder in the films. Wear tests conducted by machining particleboard using boron carbide coated WC-Co tools in the absence of methane showed the same wear rate as tools coated under higher methane pressures.

  7. 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.

  8. Tool reconstructs data input points corresponding to first order output graph

    NASA Technical Reports Server (NTRS)

    Biggs, R. E.

    1968-01-01

    Tool aids in graphic determination of input values for any first order lag system of known gain and time constant where the corresponding output function is displayed graphically and can be described by a first order differential equation. This tool permits a rapid reconstruction of input points.

  9. The Relationship of Actigraph Accelerometer Cut-Points for Estimating Physical Activity with Selected Health Outcomes: Results from NHANES 2003-06

    ERIC Educational Resources Information Center

    Loprinzi, Paul D.; Lee, Hyo; Cardinal, Bradley J.; Crespo, Carlos J.; Andersen, Ross E.; Smit, Ellen

    2012-01-01

    The purpose of this study was to examine the influence of child and adult cut-points on physical activity (PA) intensity, the prevalence of meeting PA guidelines, and association with selected health outcomes. Participants (6,578 adults greater than or equal to 18 years, and 3,174 children and adolescents less than or equal to 17 years) from the…

  10. Age, sex and ethnic differences in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Asian culture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    No nationally representative data from middle- and low-income countries have been analyzed to compare the prevalence of underweight and overweight, defined by using the Centers for Disease Control and Prevention (CDC), and the International Obesity TaskForce (IOTF) body mass index cut points. To exa...

  11. Detection and diagnosis of bearing and cutting tool faults using hidden Markov models

    NASA Astrophysics Data System (ADS)

    Boutros, Tony; Liang, Ming

    2011-08-01

    Over the last few decades, the research for new fault detection and diagnosis techniques in machining processes and rotating machinery has attracted increasing interest worldwide. This development was mainly stimulated by the rapid advance in industrial technologies and the increase in complexity of machining and machinery systems. In this study, the discrete hidden Markov model (HMM) is applied to detect and diagnose mechanical faults. The technique is tested and validated successfully using two scenarios: tool wear/fracture and bearing faults. In the first case the model correctly detected the state of the tool (i.e., sharp, worn, or broken) whereas in the second application, the model classified the severity of the fault seeded in two different engine bearings. The success rate obtained in our tests for fault severity classification was above 95%. In addition to the fault severity, a location index was developed to determine the fault location. This index has been applied to determine the location (inner race, ball, or outer race) of a bearing fault with an average success rate of 96%. The training time required to develop the HMMs was less than 5 s in both the monitoring cases.

  12. A Covariance Analysis Tool for Assessing Fundamental Limits of SIM Pointing Performance

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Kang, Bryan H.

    2007-01-01

    This paper presents a performance analysis of the instrument pointing control system for NASA's Space Interferometer Mission (SIM). SIM has a complex pointing system that uses a fast steering mirror in combination with a multirate control architecture to blend feed forward information with feedback information. A pointing covariance analysis tool (PCAT) is developed specifically to analyze systems with such complexity. The development of PCAT as a mathematical tool for covariance analysis is outlined in the paper. PCAT is then applied to studying performance of SIM's science pointing system. The analysis reveals and clearly delineates a fundamental limit that exists for SIM pointing performance. The limit is especially stringent for dim star targets. Discussion of the nature of the performance limit is provided, and methods are suggested to potentially improve pointing performance.

  13. A covariance analysis tool for assessing fundamental limits of SIM pointing performance

    NASA Astrophysics Data System (ADS)

    Bayard, David S.; Kang, Bryan H.

    2007-09-01

    This paper presents a performance analysis of the instrument pointing control system for NASA's Space Interferometer Mission (SIM). SIM has a complex pointing system that uses a fast steering mirror in combination with a multirate control architecture to blend feedforward information with feedback information. A pointing covariance analysis tool (PCAT) is developed specifically to analyze systems with such complexity. The development of PCAT as a mathematical tool for covariance analysis is outlined in the paper. PCAT is then applied to studying performance of SIM's science pointing system. The analysis reveals and clearly delineates a fundamental limit that exists for SIM pointing performance. The limit is especially stringent for dim star targets. Discussion of the nature of the performance limit is provided, and methods are suggested to potentially improve pointing performance.

  14. Ethnicity-specific obesity cut-points in the development of Type 2 diabetes – a prospective study including three ethnic groups in the United Kingdom

    PubMed Central

    Tillin, T; Sattar, N; Godsland, I F; Hughes, A D; Chaturvedi, N; Forouhi, N G

    2015-01-01

    Aims Conventional definitions of obesity, e.g. body mass index (BMI) ≥ 30 kg/m2 or waist circumference cut-points of 102 cm (men) and 88 cm (women), may underestimate metabolic risk in non-Europeans. We prospectively identified equivalent ethnicity-specific obesity cut-points for the estimation of diabetes risk in British South Asians, African-Caribbeans and Europeans. Methods We studied a population-based cohort from London, UK (1356 Europeans, 842 South Asians, 335 African-Caribbeans) who were aged 40–69 years at baseline (1988–1991), when they underwent anthropometry, fasting and post-load (75 g oral glucose tolerance test) blood tests. Incident Type 2 diabetes was identified from primary care records, participant recall and/or follow-up biochemistry. Ethnicity-specific obesity cut-points in association with diabetes incidence were estimated using negative binomial regression. Results Diabetes incidence rates (per 1000 person years) at a median follow-up of 19 years were 20.8 (95% CI: 18.4, 23.6) and 12.0 (8.3, 17.2) in South Asian men and women, 16.5 (12.7, 21.4) and 17.5 (13.0, 23.7) in African-Caribbean men and women, and 7.4 (6.3, 8.7), and 7.2 (5.3, 9.8) in European men and women. For incidence rates equivalent to those at a BMI of 30 kg/m2 in European men and women, age- and sex-adjusted cut-points were: South Asians, 25.2 (23.4, 26.6) kg/m2; and African-Caribbeans, 27.2 (25.2, 28.6) kg/m2. For South Asian and African-Caribbean men, respectively, waist circumference cut-points of 90.4 (85.0, 94.5) and 90.6 (85.0, 94.5) cm were equivalent to a value of 102 cm in European men. Waist circumference cut-points of 84.0 (74.0, 90.0) cm in South Asian women and 81.2 (71.4, 87.4) cm in African-Caribbean women were equivalent to a value of 88 cm in European women. Conclusions In prospective analyses, British South Asians and African-Caribbeans had equivalent diabetes incidence rates at substantially lower obesity levels than the conventional European cut-points

  15. Investigation of surface roughness and tool wear length with varying combination of depth of cut and feed rate of Aluminium alloy and P20 steel machining.

    NASA Astrophysics Data System (ADS)

    Varmma a/l Suparmaniam, Madan; Razlan Yusoff, Ahmad

    2016-02-01

    High-speed milling technique is often used in many industries to boost productivity of the manufacturing of high-technology components. The occurrence of wear highly limits the efficiency and accuracy of high- speed milling operations. In this paper, analysis of high-speed milling process parameters such as material removal rate, cutting speed, feed rate and depth of cut carried out by implemented to conventional milling. This experiment investigate the effects of varying combination of depth of cut and feed rate to tool wear rate length using metallurgical microscope and surface roughness using portable surface roughness tester after end milling of Aluminium and P20 steel. Results showed that feed rate significantly influences the surface roughness value while depth of cut does not as the surface roughness value keep increasing with the increase of feed rate and decreasing depth of cut. Whereas, tool wear rate almost remain unchanged indicates that material removal rate strongly contribute the wear rate. It believe that with no significant tool wear rate the results of this experiment are useful by showing that HSM technique is possible to be applied in conventional machine with extra benefits of high productivity, eliminating semi-finishing operation and reducing tool load for finishing.

  16. Epidemiologic Behavior and Estimation of an Optimal Cut-Off Point for Homeostasis Model Assessment-2 Insulin Resistance: A Report from a Venezuelan Population

    PubMed Central

    Bermúdez, Valmore; Martínez, María Sofía; Apruzzese, Vanessa; Chávez-Castillo, Mervin; Gonzalez, Robys; Torres, Yaquelín; Bello, Luis; Añez, Roberto; Chacín, Maricarmen; Toledo, Alexandra; Cabrera, Mayela; Mengual, Edgardo; Ávila, Raquel; López-Miranda, José

    2014-01-01

    Background. Mathematical models such as Homeostasis Model Assessment have gained popularity in the evaluation of insulin resistance (IR). The purpose of this study was to estimate the optimal cut-off point for Homeostasis Model Assessment-2 Insulin Resistance (HOMA2-IR) in an adult population of Maracaibo, Venezuela. Methods. Descriptive, cross-sectional study with randomized, multistaged sampling included 2,026 adult individuals. IR was evaluated through HOMA2-IR calculation in 602 metabolically healthy individuals. For cut-off point estimation, two approaches were applied: HOMA2-IR percentile distribution and construction of ROC curves using sensitivity and specificity for selection. Results. HOMA2-IR arithmetic mean for the general population was 2.21 ± 1.42, with 2.18 ± 1.37 for women and 2.23 ± 1.47 for men (P = 0.466). When calculating HOMA2-IR for the healthy reference population, the resulting p75 was 2.00. Using ROC curves, the selected cut-off point was 1.95, with an area under the curve of 0.801, sensibility of 75.3%, and specificity of 72.8%. Conclusions. We propose an optimal cut-off point of 2.00 for HOMA2-IR, offering high sensitivity and specificity, sufficient for proper assessment of IR in the adult population of our city, Maracaibo. The determination of population-specific cut-off points is needed to evaluate risk for public health problems, such as obesity and metabolic syndrome. PMID:27379332

  17. Acoustic emission from single point machining: Part 2, Signal changes with tool wear. Revised

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-12-31

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  18. Acoustic emission from single point machining: Part 2, Signal changes with tool wear

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-01-01

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  19. Cut points for mild, moderate, and severe pain among cancer and non-cancer patients: a literature review.

    PubMed

    Woo, Aaron; Lechner, Breanne; Fu, Terence; Wong, C Shun; Chiu, Nicholas; Lam, Henry; Pulenzas, Natalie; Soliman, Hany; DeAngelis, Carlo; Chow, Edward

    2015-10-01

    Defining cut points (CPs) for varying levels of pain intensity is important for assessing changes in patient's functional status, and guiding the development and evaluation of treatment options. We aimed to summarize CPs identified in the literature for mild, moderate, and severe pain on the numeric rating scale (NRS), and recommend optimal CPs for cancer and non-cancer patients. We searched MEDLINE and EMBASE (inception to May 2015) for studies that used CPs to classify pain intensity on the NRS among patients with cancer or non-cancer conditions leading to acute or chronic pain. A CP was defined as the upper bound of a mild or moderate pain category. Of 1,556 identified articles, 27 were included for review. Among patients with cancer pain, mild-moderate pain CPs ranged from 1 to 4 (mean, 3.5±1.08), with CP4 being the most recommended CP (80%). For moderate-severe pain, CPs ranged from 4 to 7 (mean, 6.2±0.92), and CP6 (50%) was the optimal CPs. Among patients with non-cancer pain, mild-moderate pain CPs ranged from 2 to 5 (mean, 3.62±0.78), and CP4 was the most frequently used CP (52.9%). For moderate-severe non-cancer pain, CPs ranged from 4 to 8 (mean, 6.5±0.99), and CP6 (41.2%) was the most frequently recommended CP. A wide range of CPs for mild, moderate, and severe pain categories were identified in the literature among both cancer and non-cancer patient populations. Further studies are needed to delineate more accurate and precise CPs for pain intensity. PMID:26541396

  20. Youden Index and Optimal Cut-Point Estimated from Observations Affected by a Lower Limit of Detection

    PubMed Central

    Ruopp, Marcus D.; Perkins, Neil J.; Whitcomb, Brian W.; Schisterman, Enrique F.

    2008-01-01

    Summary The receiver operating characteristic (ROC) curve is used to evaluate a biomarker’s ability for classifying disease status. The Youden Index (J), the maximum potential effectiveness of a biomarker, is a common summary measure of the ROC curve. In biomarker development, levels may be unquantifiable below a limit of detection (LOD) and missing from the overall dataset. Disregarding these observations may negatively bias the ROC curve and thus J. Several correction methods have been suggested for mean estimation and testing; however, little has been written about the ROC curve or its summary measures. We adapt non-parametric (empirical) and semi-parametric (ROC-GLM [generalized linear model]) methods and propose parametric methods (maximum likelihood (ML)) to estimate J and the optimal cut-point (c*) for a biomarker affected by a LOD. We develop unbiased estimators of J and c* via ML for normally and gamma distributed biomarkers. Alpha level confidence intervals are proposed using delta and bootstrap methods for the ML, semi-parametric, and non-parametric approaches respectively. Simulation studies are conducted over a range of distributional scenarios and sample sizes evaluating estimators’ bias, root-mean square error, and coverage probability; the average bias was less than one percent for ML and GLM methods across scenarios and decreases with increased sample size. An example using polychlorinated biphenyl levels to classify women with and without endometriosis illustrates the potential benefits of these methods. We address the limitations and usefulness of each method in order to give researchers guidance in constructing appropriate estimates of biomarkers’ true discriminating capabilities. PMID:18435502

  1. Method and device for determining the position of a cutting tool relative to the rotational axis of a spindle-mounted workpiece

    DOEpatents

    Williams, R.R.

    1980-09-03

    The present invention is directed to a method and device for determining the location of a cutting tool with respect to the rotational axis of a spindle-mounted workpiece. A vacuum cup supporting a machinable sacrificial pin is secured to the workpiece at a location where the pin will project along and encompass the rotational axis of the workpiece. The pin is then machined into a cylinder. The position of the surface of the cutting tool contacting the machine cylinder is spaced from the rotational axis of the workpiece a distance equal to the radius of the cylinder.

  2. Method and device for determining the position of a cutting tool relative to the rotational axis of a spindle-mounted workpiece

    DOEpatents

    Williams, Richard R.

    1982-01-01

    The present invention is directed to a method and device for determining the location of a cutting tool with respect to the rotational axis of a spindle-mounted workpiece. A vacuum cup supporting a machinable sacrifical pin is secured to the workpiece at a location where the pin will project along and encompass the rotational axis of the workpiece. The pin is then machined into a cylinder. The position of the surface of the cutting tool contacting the machine cylinder is spaced from the rotational aixs of the workpiece a distance equal to the radius of the cylinder.

  3. search.bioPreprint: a discovery tool for cutting edge, preprint biomedical research articles

    PubMed Central

    Iwema, Carrie L.; LaDue, John; Zack, Angela; Chattopadhyay, Ansuman

    2016-01-01

    The time it takes for a completed manuscript to be published traditionally can be extremely lengthy. Article publication delay, which occurs in part due to constraints associated with peer review, can prevent the timely dissemination of critical and actionable data associated with new information on rare diseases or developing health concerns such as Zika virus. Preprint servers are open access online repositories housing preprint research articles that enable authors (1) to make their research immediately and freely available and (2) to receive commentary and peer review prior to journal submission. There is a growing movement of preprint advocates aiming to change the current journal publication and peer review system, proposing that preprints catalyze biomedical discovery, support career advancement, and improve scientific communication. While the number of articles submitted to and hosted by preprint servers are gradually increasing, there has been no simple way to identify biomedical research published in a preprint format, as they are not typically indexed and are only discoverable by directly searching the specific preprint server websites. To address this issue, we created a search engine that quickly compiles preprints from disparate host repositories and provides a one-stop search solution. Additionally, we developed a web application that bolsters the discovery of preprints by enabling each and every word or phrase appearing on any web site to be integrated with articles from preprint servers. This tool, search.bioPreprint, is publicly available at http://www.hsls.pitt.edu/resources/preprint. PMID:27508060

  4. search.bioPreprint: a discovery tool for cutting edge, preprint biomedical research articles.

    PubMed

    Iwema, Carrie L; LaDue, John; Zack, Angela; Chattopadhyay, Ansuman

    2016-01-01

    The time it takes for a completed manuscript to be published traditionally can be extremely lengthy. Article publication delay, which occurs in part due to constraints associated with peer review, can prevent the timely dissemination of critical and actionable data associated with new information on rare diseases or developing health concerns such as Zika virus. Preprint servers are open access online repositories housing preprint research articles that enable authors (1) to make their research immediately and freely available and (2) to receive commentary and peer review prior to journal submission. There is a growing movement of preprint advocates aiming to change the current journal publication and peer review system, proposing that preprints catalyze biomedical discovery, support career advancement, and improve scientific communication. While the number of articles submitted to and hosted by preprint servers are gradually increasing, there has been no simple way to identify biomedical research published in a preprint format, as they are not typically indexed and are only discoverable by directly searching the specific preprint server websites. To address this issue, we created a search engine that quickly compiles preprints from disparate host repositories and provides a one-stop search solution. Additionally, we developed a web application that bolsters the discovery of preprints by enabling each and every word or phrase appearing on any web site to be integrated with articles from preprint servers. This tool, search.bioPreprint, is publicly available at http://www.hsls.pitt.edu/resources/preprint. PMID:27508060

  5. MGDS: Free, on-line, cutting-edge tools to enable the democratisation of geoscience data

    NASA Astrophysics Data System (ADS)

    Goodwillie, A. M.; Ryan, W. B.; O'Hara, S.; Ferrini, V.; Arko, R. A.; Coplan, J.; Chan, S.; Carbotte, S. M.; Nitsche, F. O.; Bonczkowski, J.; Morton, J. J.; Weissel, R.; Leung, A.

    2010-12-01

    The availability of user-friendly, effective cyber-information resources for accessing and manipulating geoscience data has grown rapidly in recent years. Based at Lamont-Doherty Earth Observatory the MGDS group has developed a number of free tools that have wide application across the geosciences for both educators and researchers. A simple web page (http://www.marine-geo.org/) allows users to search for and download many types of data by key word, geographical region, or published citation. The popular Create Maps and Grids function and the downloadable Google Earth-compatible KML files appeal to a wide user base. MGDS MediaBank galleries (http://media.marine-geo.org/) enable users to view and download compelling images that are purposefully selected for their educational value from NSF-funded field programs. GeoMapApp (http://www.geomapapp.org), a free map-based interactive tool that works on any machine, is increasingly being adopted across a broad suite of users from middle school students to university researchers. GeoMapApp allows users to plot, manipulate and present data in an intuitive geographical reference frame. GeoMapApp offers a convenient way to explore the wide range of built-in data sets, to quickly generate maps and images that aid visualisation and, when importing their own gridded and tabular data sets, to access the same rich built-in functionality. A user guide, short multi-media tutorials, and webinar are available on-line. The regularly-updated Global Multi-Resolution Topography (GMRT) Synthesis is used as the default GeoMapApp base map and is an increasingly popular means to rapidly create location maps. Additionally, the layer manager offers a fast way to overlay and compare multiple data sets and is augmented by the ability to alter layer transparency so that underlying layers become visible. Examples of GeoMapApp built-in data sets include high-resolution land topography and ocean floor bathymetry derived from satellite and multi

  6. Coatings for metal cutting and forming tools. January 1970-March 1989 (Citations from the COMPENDEX data base). Report for January 1970-March 1989

    SciTech Connect

    Not Available

    1989-04-01

    This bibliography contains citations concerning the bond and wear characteristics of hard, antifriction, and thermal-insulating coatings on metal cutting and forming tools and dies. The metal carbides and oxides, ceramic coatings and their deposition techniques, CVD, ion nitriding, and sputtering are included. The effects of coatings on tool wear, and performance comparisons of various substrate/coating combinations are discussed. (This updated bibliography contains 258 citations, 94 of which are new entries to the previous edition.)

  7. Comparison of Interferon-γ Release Assay to Two Cut-Off Points of Tuberculin Skin Test to Detect Latent Mycobacterium tuberculosis Infection in Primary Health Care Workers

    PubMed Central

    de Souza, Fernanda Mattos; do Prado, Thiago Nascimento; Pinheiro, Jair dos Santos; Peres, Renata Lyrio; Lacerda, Thamy Carvalho; Loureiro, Rafaela Borge; Carvalho, Jose Américo; Fregona, Geisa; Dias, Elias Santos; Cosme, Lorrayne Beliqui; Rodrigues, Rodrigo Ribeiro; Riley, Lee Wood; Maciel, Ethel Leonor Noia

    2014-01-01

    Background An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. Methods A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. Results We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST−/QFT− group, risk factors for discordance in the TST+/QFT− group with TST cut-off of ≥5 mm included age between 41–45 years [OR = 2.70; CI 95%: 1.32–5.51] and 46–64 years [OR = 2.04; CI 95%: 1.05–3.93], BCG scar [OR = 2.72; CI 95%: 1.40–5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09–4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03–4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01–2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05–2.62], were significantly associated with the TST+/QFT− group. No statistically significant associations were found among the TST−/QFT+ discordant group with either TST cut-off value. Conclusions Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed. PMID:25137040

  8. Precision-Cut Kidney Slices as a Tool to Understand the Dynamics of Extracellular Matrix Remodeling in Renal Fibrosis

    PubMed Central

    Genovese, Federica; Kàrpàti, Zsolt S.; Nielsen, Signe H.; Karsdal, Morten A.

    2016-01-01

    The aim of this study was to set up an ex vivo model for renal interstitial fibrosis in order to investigate the extracellular matrix (ECM) turnover profile in the fibrotic kidney. We induced kidney fibrosis in fourteen 12-week-old male Sprague Dawley rats by unilateral ureteral obstruction (UUO) surgery of the right ureter. The left kidney (contralateral) was used as internal control. Six rats were sham operated and used as the control group. Rats were terminated two weeks after the surgery; the kidneys were excised and precision-cut kidney slices (PCKSs) were cultured for five days in serum-free medium. Markers of collagen type I formation (P1NP), collagen type I and III degradation (C1M and C3M), and α-smooth muscle actin (αSMA) were measured in the PCKS supernatants by enzyme-linked immunosorbent assay. P1NP, C1M, C3M, and α-SMA were increased up to 2- to 13-fold in supernatants of tissue slices from the UUO-ligated kidneys compared with the contralateral kidneys (P < 0.001) and with the kidneys of sham-operated animals (P < 0.0001). The markers could also reflect the level of fibrosis in different animals. The UUO PCKS ex vivo model provides a valuable translational tool for investigating the extracellular matrix remodeling associated with renal interstitial fibrosis. PMID:27257368

  9. Tribological and cutting behavior of silicon nitride tools coated with monolayer- and multilayer-microcrystalline HFCVD diamond films

    NASA Astrophysics Data System (ADS)

    Chen, Naichao; Shen, Bin; Yang, Guodong; Sun, Fanghong

    2013-01-01

    Monolayer-micrometric (MN-MCD), monolayer-submicrometric (MN-SMCD) and multilayer-micrometric (MT-MCD) diamond films are grown on silicon nitride substrates by hot filament chemical vapor deposition (HFCVD) technique. The as-deposited diamond films are characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectrometer (EDS), Raman spectrum and 3D surface topography. Tribological properties are assessed by the sliding tests using a reciprocal motion ball-on-flat (BOF) configuration. The friction coefficients are measured as 0.126 for the MN-MCD films, 0.076 for the MN-SMCD films and 0.071 for the MT-MCD films during dry sliding against silicon nitride counterface. The different carbon content of the films may result in the visible diminution of friction coefficient for the MT-MCD films relative to the MN-MCD films. The results show that the MN-MCD and MT-MCD films present the much higher wear resistance than the MN-SMCD films. Meanwhile, the cutting performances of as-deposited diamond films are evaluated by machining aluminum-silicon alloy material. The experimental results show that the MT-MCD insert presents the best behavior regarding the tool wear.

  10. Precision-Cut Kidney Slices as a Tool to Understand the Dynamics of Extracellular Matrix Remodeling in Renal Fibrosis.

    PubMed

    Genovese, Federica; Kàrpàti, Zsolt S; Nielsen, Signe H; Karsdal, Morten A

    2016-01-01

    The aim of this study was to set up an ex vivo model for renal interstitial fibrosis in order to investigate the extracellular matrix (ECM) turnover profile in the fibrotic kidney. We induced kidney fibrosis in fourteen 12-week-old male Sprague Dawley rats by unilateral ureteral obstruction (UUO) surgery of the right ureter. The left kidney (contralateral) was used as internal control. Six rats were sham operated and used as the control group. Rats were terminated two weeks after the surgery; the kidneys were excised and precision-cut kidney slices (PCKSs) were cultured for five days in serum-free medium. Markers of collagen type I formation (P1NP), collagen type I and III degradation (C1M and C3M), and α-smooth muscle actin (αSMA) were measured in the PCKS supernatants by enzyme-linked immunosorbent assay. P1NP, C1M, C3M, and α-SMA were increased up to 2- to 13-fold in supernatants of tissue slices from the UUO-ligated kidneys compared with the contralateral kidneys (P < 0.001) and with the kidneys of sham-operated animals (P < 0.0001). The markers could also reflect the level of fibrosis in different animals. The UUO PCKS ex vivo model provides a valuable translational tool for investigating the extracellular matrix remodeling associated with renal interstitial fibrosis. PMID:27257368

  11. Sensitivity and Specificity Improvement in Abdominal Obesity Diagnosis Using Cluster Analysis during Waist Circumference Cut-Off Point Selection

    PubMed Central

    Bermúdez, Valmore; Añez, Roberto; Toledo, Alexandra; Bello, Luis; Apruzzese, Vanessa; González, Robys; Chacín, Maricarmen; Cabrera, Mayela; Cano, Clímaco; Velasco, Manuel; López-Miranda, José

    2015-01-01

    Introduction. The purpose of this study was to analyze the influence of metabolic phenotypes during the construction of ROC curves for waist circumference (WC) cutpoint selection. Materials and Methods. A total of 1,902 subjects of both genders were selected from the Maracaibo City Metabolic Syndrome Prevalence Study database. Two-Step Cluster Analysis (TSCA) was applied to select metabolically healthy and sick men and women. ROC curves were constructed to determine WC cutoff points by gender. Results. Through TSCA, metabolic phenotype predictive variables were selected: HOMA2-IR and HOMA2-βcell for women and HOMA2-IR, HOMA2-βcell, and TAG for men. Subjects were classified as healthy normal weight, metabolically obese normal weight, healthy and metabolically disturbed overweight, and healthy and metabolically disturbed obese. Final WC cutpoints were 91.50 cm for women (93.4% sensitivity, 93.7% specificity) and 98.15 cm for men (96% sensitivity, 99.5% specificity). Conclusions. TSCA in the selection of the groups used in ROC curves construction proved to be an important tool, aiding in the detection of MOWN and MHO which cannot be identified with WC alone. The resulting WC cutpoints were <91.00 cm for women and <98.00 cm for men. Furthermore, anthropometry is insufficient to determine healthiness, and, biochemical analysis is needed to properly filter subjects during classification. PMID:25945356

  12. Acoustic emission from single point machining: Source mechanisms and signal changes with tool wear

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1994-05-01

    Acoustic emission (AE) was monitored during single point, continuous machining of 4340 steel and Ti-6Al-4V as a function of heat treatment. Heat treatments that increase the strength of 4340 steel substantially increase the amount of AE produced during deformation, while heat treatments that increase the strength of Ti-6Al-4V dramatically decrease the amount of AE produced during deformation. There was little change in root-mean-square (rms) AE level during machining for either alloy as a function of prior heat treatment, demonstrating that chip deformation is not a major source of AE in single point machining. Additional data from a variety of materials suggest that sliding friction between the nose and/or flank of the tool and the newly machined surface is the primary source of AE. Changes in AE signal characteristics with tool wear were also monitored during single point machining. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristics with wear for a given material may be sufficient to be used to monitor tool wear.

  13. Microsoft Producer: A Software Tool for Creating Multimedia PowerPoint[R] Presentations

    ERIC Educational Resources Information Center

    Leffingwell, Thad R.; Thomas, David G.; Elliott, William H.

    2007-01-01

    Microsoft[R] Producer[R] is a powerful yet user-friendly PowerPoint companion tool for creating on-demand multimedia presentations. Instructors can easily distribute these presentations via compact disc or streaming media over the Internet. We describe the features of the software, system requirements, and other required hardware. We also describe…

  14. Structural vascular disease in Africans: Performance of ethnic-specific waist circumference cut points using logistic regression and neural network analyses: The SABPA study.

    PubMed

    Botha, J; de Ridder, J H; Potgieter, J C; Steyn, H S; Malan, L

    2013-10-01

    A recently proposed model for waist circumference cut points (RPWC), driven by increased blood pressure, was demonstrated in an African population. We therefore aimed to validate the RPWC by comparing the RPWC and the Joint Statement Consensus (JSC) models via Logistic Regression (LR) and Neural Networks (NN) analyses. Urban African gender groups (N=171) were stratified according to the JSC and RPWC cut point models. Ultrasound carotid intima media thickness (CIMT), blood pressure (BP) and fasting bloods (glucose, high density lipoprotein (HDL) and triglycerides) were obtained in a well-controlled setting. The RPWC male model (LR ROC AUC: 0.71, NN ROC AUC: 0.71) was practically equal to the JSC model (LR ROC AUC: 0.71, NN ROC AUC: 0.69) to predict structural vascular -disease. Similarly, the female RPWC model (LR ROC AUC: 0.84, NN ROC AUC: 0.82) and JSC model (LR ROC AUC: 0.82, NN ROC AUC: 0.81) equally predicted CIMT as surrogate marker for structural vascular disease. Odds ratios supported validity where prediction of CIMT revealed -clinical -significance, well over 1, for both the JSC and RPWC models in African males and females (OR 3.75-13.98). In conclusion, the proposed RPWC model was substantially validated utilizing linear and non-linear analyses. We therefore propose ethnic-specific WC cut points (African males, ≥90 cm; -females, ≥98 cm) to predict a surrogate marker for structural vascular disease. PMID:23934678

  15. The Cut-Off Point and Boundary Values of Waist-to-Height Ratio as an Indicator for Cardiovascular Risk Factors in Chinese Adults from the PURE Study

    PubMed Central

    Peng, Yaguang; Li, Wei; Wang, Yang; Bo, Jian; Chen, Hui

    2015-01-01

    To explore a scientific boundary of WHtR to evaluate central obesity and CVD risk factors in a Chinese adult population. The data are from the Prospective Urban Rural Epidemiology (PURE) China study that was conducted from 2005–2007. The final study sample consisted of 43 841 participants (18 019 men and 25 822 women) aged 35–70 years. According to the group of CVD risk factors proposed by Joint National Committee 7 version and the clustering of risk factors, some diagnosis parameters, such as sensitivity, specificity and receiver operating characteristic (ROC) curve least distance were calculated for hypertension, diabetes, high serum triglyceride (TG), high serum low density lipoprotein cholesterol (LDL-C), low serum high density lipoprotein cholesterol (HDL-C) and clustering of risk factors (number≥2) to evaluate the efficacy at each value of the WHtR cut-off point. The upper boundary value for severity was fixed on the point where the specificity was above 90%. The lower boundary value, which indicated above underweight, was determined by the percentile distribution of WHtR, specifically the 5th percentile (P5) for both males and females population. Then, based on convenience and practical use, the optimal boundary values of WHtR for underweight and obvious central obesity were determined. For the whole study population, the optimal WHtR cut-off point for the CVD risk factor cluster was 0.50. The cut-off points for severe central obesity were 0.57 in the whole population. The upper boundary values of WHtR to detect the risk factor cluster with specificity above 90% were 0.55 and 0.58 for men and women, respectively. Additionally, the cut-off points of WHtR for each of four cardiovascular risk factors with specificity above 90% in males ranged from 0.55 to 0.56, whereas in females, it ranged from 0.57 to 0.58. The P5 of WHtR, which represents the lower boundary values of WHtR that indicates above underweight, was 0.40 in the whole population. WHtR 0.50 was

  16. Cutting force-based real-time estimation of tool wear in face milling using a combination of signal processing techniques

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, P.; Sengupta, D.; Mukhopadhyay, S.

    2007-08-01

    In this paper, combinations of signal processing techniques for real-time estimation of tool wear in face milling using cutting force signals are presented. Three different strategies based on linear filtering, time-domain averaging and wavelet transformation techniques are adopted for extracting relevant features from the measured signals. Sensor fusion at feature level is used in search of an improved and robust tool wear model. Isotonic regression and exponential smoothing techniques are introduced to enforce monotonicity and smoothness of the extracted features. At the first stage, multiple linear regression models are developed for specific cutting conditions using the extracted features. The best features are identified on the basis of a statistical model selection criterion. At the second stage, the first-stage models are combined, in accordance with proven theory, into a single tool wear model, including the effect of cutting parameters. The three chosen strategies show improvements over those reported in the literature, in the case of training data as well as test data used for validation—for both laboratory and industrial experiments. A method for calculating the probabilistic worst-case prediction of tool wear is also developed for the final tool wear model.

  17. Cutting Guide for Fibrous Sheets

    NASA Technical Reports Server (NTRS)

    Warren, A., D.

    1985-01-01

    Tool facilitates repetitive cutting of fibrous sheets. Flexible aluminum tape allows metal strips folded back on themselves, exposing fresh material for cutting. More than one strip folded back, and cutting width therefore increased in multiples of strip width. Developed for cutting strips of alumina-fiber matting, tool also used on such materials as felts, textiles, and sheet metals.

  18. Development of Way Point Planning Tool in Response to NASA Field Campaign Challenges

    NASA Astrophysics Data System (ADS)

    He, M.; Hardin, D. M.; Conover, H.; Graves, S. J.; Meyer, P.; Blakeslee, R. J.; Goodman, M. L.

    2012-12-01

    Airborne real time observations are a major component of NASA's Earth Science research and satellite ground validation studies. For mission scientists, planning a research aircraft mission within the context of meeting the science objectives is a complex task because it requires real time situational awareness of the weather conditions that affect the aircraft track. Multiple aircrafts are often involved in NASA field campaigns. The coordination of the aircrafts with satellite overpasses, other airplanes and the constantly evolving, dynamic weather conditions often determines the success of the campaign. A flight planning tool is needed to provide situational awareness information to the mission scientists, and help them plan and modify the flight tracks. Scientists at the University of Alabama-Huntsville and the NASA Marshall Space Flight Center developed the Waypoint Planning Tool, an interactive software tool that enables scientists to develop their own flight plans (also known as waypoints) with point-and-click mouse capabilities on a digital map filled with real time raster and vector data. The development of this Waypoint Planning Tool demonstrates the significance of mission support in responding to the challenges presented during NASA field campaigns. Analysis during and after each campaign helped identify both issues and new requirements, and initiated the next wave of development. Currently the Waypoint Planning Tool has gone through three rounds of development and analysis processes. The development of this waypoint tool is directly affected by the technology advances on GIS/Mapping technologies. From the standalone Google Earth application and simple KML functionalities, to Google Earth Plugin and Java Web Start/Applet on web platform, and to the rising open source GIS tools with new JavaScript frameworks, the Waypoint Planning Tool has entered its third phase of technology advancement. The newly innovated, cross-platform, modular designed Java

  19. Cutting fluid study for single crystal silicon

    SciTech Connect

    Chargin, D.

    1998-05-05

    An empirical study was conducted to evaluate cutting fluids for Single Point Diamond Turning (SPDT) of single crystal silicon. The pH of distilled waster was adjusted with various additives the examine the effect of pH on cutting operations. Fluids which seemed to promote ductile cutting appeared to increase tool wear as well, an undesirable tradeoff. High Ph sodium hydroxide solutions showed promise for further research, as they yielded the best combination of reduced tool wear and good surface finish in the ductile regime. Negative rake tools were verified to improve the surface finish, but the negative rake tools used in the experiments also showed much higher wear than conventional 0{degree} rake tools. Effects of crystallographic orientation on SPDT, such as star patterns of fracture damage forming near the center of the samples, were observed to decrease with lower feedrates. Silicon chips were observed and photographed, indicative of a ductile materials removal process.

  20. Material Behavior At The Extreme Cutting Edge In Bandsawing

    NASA Astrophysics Data System (ADS)

    Sarwar, Mohammed; Haider, Julfikar; Persson, Martin; Hellbergh, Hâkan

    2011-01-01

    In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 μm-50 μm) being smaller than or equal to the cutting edge radius (5 μm-15 μm). This situation can lead to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. "High Speed Photography" has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during "High Speed Photography" and "Quick Stop" process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.

  1. Material Behavior At The Extreme Cutting Edge In Bandsawing

    SciTech Connect

    Sarwar, Mohammed; Haider, Julfikar; Persson, Martin; Hellbergh, Haakan

    2011-01-17

    In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 {mu}m-50 {mu}m) being smaller than or equal to the cutting edge radius (5 {mu}m-15 {mu}m). This situation can lead to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. ''High Speed Photography'' has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during ''High Speed Photography'' and ''Quick Stop'' process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.

  2. The new CutSprof sampling tool and method for micromorphological and microfacies analyses of subsurface salt marsh sediments, Algarve, Portugal

    NASA Astrophysics Data System (ADS)

    Araújo-Gomes, João; Ramos-Pereira, Ana

    2015-02-01

    A new tool and method for collecting undisturbed subsurface samples in estuarine environments by means of trenching, timbering and sectioning is presented. Smoothing of sidewalls is achieved by a so-called cutting sediment profiler (CutSprof), while water draining into the trench is cleared by pumping. From smoothed sidewall sections, undisturbed thin sediment slices can then be collected for micromorphological and microfacies analyses. Results demonstrating the successful application of this procedure are presented for salt marshes of the Bensafrim River estuary (Lagos, Algarve, Portugal). In addition to palaeo-reconstructions in salt marsh settings, the CutSprof would be highly suitable in various other research domains as well as for environmental management purposes, particularly where sampling below the groundwater table is desirable to explore, for example, animal-sediment relationships in tidal-flat and mangrove ecosystems as well as the dynamics of coastal wetlands today threatened by ever-increasing anthropogenic influence.

  3. The Way Point Planning Tool: Real Time Flight Planning for Airborne Science

    NASA Technical Reports Server (NTRS)

    He, Yubin; Blakeslee, Richard; Goodman, Michael; Hall, John

    2012-01-01

    Airborne real time observation are a major component of NASA's Earth Science research and satellite ground validation studies. For mission scientist, planning a research aircraft mission within the context of meeting the science objective is a complex task because it requires real time situational awareness of the weather conditions that affect the aircraft track. Multiple aircraft are often involved in the NASA field campaigns the coordination of the aircraft with satellite overpasses, other airplanes and the constantly evolving dynamic weather conditions often determine the success of the campaign. A flight planning tool is needed to provide situational awareness information to the mission scientist and help them plan and modify the flight tracks successfully. Scientists at the University of Alabama Huntsville and the NASA Marshal Space Flight Center developed the Waypoint Planning Tool (WPT), an interactive software tool that enables scientist to develop their own flight plans (also known as waypoints), with point and click mouse capabilities on a digital map filled with time raster and vector data. The development of this Waypoint Planning Tool demonstrates the significance of mission support in responding to the challenges presented during NASA field campaigns. Analyses during and after each campaign helped identify both issues and new requirements, initiating the next wave of development. Currently the Waypoint Planning Tool has gone through three rounds of development and analysis processes. The development of this waypoint tool is directly affected by the technology advances on GIS/Mapping technologies. From the standalone Google Earth application and simple KML functionalities to the Google Earth Plugin and Java Web Start/Applet on web platform, as well as to the rising open source GIS tools with new JavaScript frameworks, the Waypoint planning Tool has entered its third phase of technology advancement. The newly innovated, cross-platform, modular designed

  4. Spectrum of classes of point emitters: new tool for nonparaxial optical field modeling.

    PubMed

    Castañeda, Román; Muñoz, Hernán

    2016-08-01

    Numerical modeling of optical fields provides valuable support to both theoretical research and technological development in many optics fields. Fourier methods have been the most widely used tools of numerical modeling. However, important limitations have restricted their application in contemporary research that involve high numerical apertures, short propagation distances, and spatially partially coherent states of light, for instance. The spectrum of classes of point emitters is introduced as a numerical tool that overcomes such limitations for the design, analysis, and synthesis of nonparaxial optical fields in arbitrary states of spatial coherence. In this context, optical processing is realized as the filtering on the spectrum of classes of point emitters performed by the complex degree of spatial coherence that could be implemented dynamically by using programmable devices. PMID:27505639

  5. Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

    PubMed

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

    2015-12-01

    Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm. PMID:26452371

  6. Pickles: A Visual Tool for Pointing the Hubble Space Telescope and Displaying Star Catalogs

    NASA Astrophysics Data System (ADS)

    McCartney, J.; McArthur, B.; Jefferys, W.

    1994-05-01

    Pickles is a Macintosh program that was first developed by the HST Astrometry Team as a tool for determining pointings and rolls of the Hubble Space Telescope when desired target and guide stars were in the fine guidance sensor "pickles". Over time, it has become a much more sophisticated tool, and now includes apertures for all the Hubble science instruments, the ability to add user-defined apertures and the ability to display an 8! x 8 degree (HST Fixed Head Star Tracker) window. It has the new aperture locations from the post-servicing mission telescope. Because of its ability to extract and display star positions from the Guide Star Catalog, ACRS, SAO, AGK3 catalog CD ROMs, pickles is also being used in other astronomical projects. Pickles is a powerful, easy-to-use tool for visualization of star positions for any purpose.

  7. Synergistically toughening effect of SiC whiskers and nanoparticles in Al2O3-based composite ceramic cutting tool material

    NASA Astrophysics Data System (ADS)

    Liu, Xuefei; Liu, Hanlian; Huang, Chuanzhen; Wang, Limei; Zou, Bin; Zhao, Bin

    2016-06-01

    In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al2O3-SiCw-SiCnp advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al2O3 matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al2O3-SiCw-SiCnp composite with both 20 vol% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al2O3-SiCw-SiCnp is 730±95 MPa and fracture toughness is 5.6±0.6 MPa·m1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.

  8. 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.

  9. Optimal cut-off points of fasting plasma glucose for two-step strategy in estimating prevalence and screening undiagnosed diabetes and pre-diabetes in Harbin, China.

    PubMed

    Bao, Chundan; Zhang, Dianfeng; Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan

    2015-01-01

    To identify optimal cut-off points of fasting plasma glucose (FPG) for two-step strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-step strategy, and optimal FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The optimal FPG cut-off points for two-step strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-step strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-step strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using optimal FPG cut-off points for two-step strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition. PMID:25785585

  10. Optimal Cut-Off Points of Fasting Plasma Glucose for Two-Step Strategy in Estimating Prevalence and Screening Undiagnosed Diabetes and Pre-Diabetes in Harbin, China

    PubMed Central

    Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan

    2015-01-01

    To identify optimal cut-off points of fasting plasma glucose (FPG) for two-step strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-step strategy, and optimal FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The optimal FPG cut-off points for two-step strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-step strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-step strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using optimal FPG cut-off points for two-step strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition. PMID:25785585

  11. Faulting at Mormon Point, Death Valley, California: A low-angle normal fault cut by high-angle faults

    NASA Astrophysics Data System (ADS)

    Keener, Charles; Serpa, Laura; Pavlis, Terry L.

    1993-04-01

    New geophysical and fault kinematic studies indicate that late Cenozoic basin development in the Mormon Point area of Death Valley, California, was accommodated by fault rotations. Three of six fault segments recognized at Mormon Point are now inactive and have been rotated to low dips during extension. The remaining three segments are now active and moderately to steeply dipping. From the geophysical data, one active segment appears to offset the low-angle faults in the subsurface of Death Valley.

  12. PypeTree: A Tool for Reconstructing Tree Perennial Tissues from Point Clouds

    PubMed Central

    Delagrange, Sylvain; Jauvin, Christian; Rochon, Pascal

    2014-01-01

    The reconstruction of trees from point clouds that were acquired with terrestrial LiDAR scanning (TLS) may become a significant breakthrough in the study and modelling of tree development. Here, we develop an efficient method and a tool based on extensive modifications to the skeletal extraction method that was first introduced by Verroust and Lazarus in 2000. PypeTree, a user-friendly and open-source visual modelling environment, incorporates a number of improvements into the original skeletal extraction technique, making it better adapted to tackle the challenge of tree perennial tissue reconstruction. Within PypeTree, we also introduce the idea of using semi-supervised adjustment tools to address methodological challenges that are associated with imperfect point cloud datasets and which further improve reconstruction accuracy. The performance of these automatic and semi-supervised approaches was tested with the help of synthetic models and subsequently validated on real trees. Accuracy of automatic reconstruction greatly varied in terms of axis detection because small (length < 3.5 cm) branches were difficult to detect. However, as small branches account for little in terms of total skeleton length, mean reconstruction error for cumulated skeleton length only reached 5.1% and 1.8% with automatic or semi-supervised reconstruction, respectively. In some cases, using the supervised tools, a perfect reconstruction of the perennial tissue could be achieved. PMID:24599190

  13. PypeTree: a tool for reconstructing tree perennial tissues from point clouds.

    PubMed

    Delagrange, Sylvain; Jauvin, Christian; Rochon, Pascal

    2014-01-01

    The reconstruction of trees from point clouds that were acquired with terrestrial LiDAR scanning (TLS) may become a significant breakthrough in the study and modelling of tree development. Here, we develop an efficient method and a tool based on extensive modifications to the skeletal extraction method that was first introduced by Verroust and Lazarus in 2000. PypeTree, a user-friendly and open-source visual modelling environment, incorporates a number of improvements into the original skeletal extraction technique, making it better adapted to tackle the challenge of tree perennial tissue reconstruction. Within PypeTree, we also introduce the idea of using semi-supervised adjustment tools to address methodological challenges that are associated with imperfect point cloud datasets and which further improve reconstruction accuracy. The performance of these automatic and semi-supervised approaches was tested with the help of synthetic models and subsequently validated on real trees. Accuracy of automatic reconstruction greatly varied in terms of axis detection because small (length < 3.5 cm) branches were difficult to detect. However, as small branches account for little in terms of total skeleton length, mean reconstruction error for cumulated skeleton length only reached 5.1% and 1.8% with automatic or semi-supervised reconstruction, respectively. In some cases, using the supervised tools, a perfect reconstruction of the perennial tissue could be achieved. PMID:24599190

  14. 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.

  15. An interactive tool for design and support of lunar, gravity assist, and libration point trajectories

    NASA Technical Reports Server (NTRS)

    Carrico, J.; Schiff, C.; Roszman, L.; Hooper, H.; Folta, D.; Richon, K.

    1993-01-01

    The 'Swingby' interactive tool for design, analysis, and support of maneuver planning for missions that involve transfers to the moon, the lunar orbits, multiple-gravity assists, and the libration-point orbits, runs on a PC and uses pull-down and pop-up menus to allow users to change physical constants and select perturbations for inclusion. Swingby can also target by ascertain parameters, or allow the computer to generate goals on the basis of mission requirements. Rapid mission analyses, operational maneuvers, and contingency plans are thereby obtainable.

  16. Fatty acid ethyl esters in hair as alcohol markers: estimating a reliable cut-off point by evaluation of 1,057 autopsy cases.

    PubMed

    Hastedt, Martin; Bossers, Lydia; Krumbiegel, Franziska; Herre, Sieglinde; Hartwig, Sven

    2013-06-01

    Alcohol abuse is a widespread problem, especially in Western countries. Therefore, it is important to have markers of alcohol consumption with validated cut-off points. For many years research has focused on analysis of hair for alcohol markers, but data on the performance and reliability of cut-off values are still lacking. Evaluating 1,057 cases from 2005 to 2011, included a large sample group for the estimation of an applicable cut-off value when compared to earlier studies on fatty acid ethyl esters (FAEEs) in hair. The FAEEs concentrations in hair, police investigation reports, medical history, and the macroscopic and microscopic alcohol-typical results from autopsy, such as liver, pancreas, and cardiac findings, were taken into account in this study. In 80.2 % of all 1,057 cases pathologic findings that may be related to alcohol abuse were reported. The cases were divided into social drinkers (n = 168), alcohol abusers (n = 502), and cases without information on alcohol use. The median FAEEs concentration in the group of social drinkers was 0.302 ng/mg (range 0.008-14.3 ng/mg). In the group of alcohol abusers a median of 1.346 ng/mg (range 0.010-83.7 ng/mg) was found. Before June 2009 the hair FAEEs test was routinely applied to a proximal hair segment of 0-6 cm, changing to a routinely investigated hair length of 3 cm after 2009, as proposed by the Society of Hair Testing (SoHT). The method showed significant differences between the groups of social drinkers and alcoholics, leading to an improvement in the postmortem detection of alcohol abuse. Nevertheless, the performance of the method was rather poor, with an area under the curve calculated from receiver operating characteristic (ROC curve AUC) of 0.745. The optimum cut-off value for differentiation between social and chronic excessive drinking calculated for hair FAEEs was 1.08 ng/mg, with a sensitivity of 56 % and a specificity of 80 %. In relation to the "Consensus on Alcohol Markers 2012

  17. Structure Based Thermostability Prediction Models for Protein Single Point Mutations with Machine Learning Tools.

    PubMed

    Jia, Lei; Yarlagadda, Ramya; Reed, Charles C

    2015-01-01

    Thermostability issue of protein point mutations is a common occurrence in protein engineering. An application which predicts the thermostability of mutants can be helpful for guiding decision making process in protein design via mutagenesis. An in silico point mutation scanning method is frequently used to find "hot spots" in proteins for focused mutagenesis. ProTherm (http://gibk26.bio.kyutech.ac.jp/jouhou/Protherm/protherm.html) is a public database that consists of thousands of protein mutants' experimentally measured thermostability. Two data sets based on two differently measured thermostability properties of protein single point mutations, namely the unfolding free energy change (ddG) and melting temperature change (dTm) were obtained from this database. Folding free energy change calculation from Rosetta, structural information of the point mutations as well as amino acid physical properties were obtained for building thermostability prediction models with informatics modeling tools. Five supervised machine learning methods (support vector machine, random forests, artificial neural network, naïve Bayes classifier, K nearest neighbor) and partial least squares regression are used for building the prediction models. Binary and ternary classifications as well as regression models were built and evaluated. Data set redundancy and balancing, the reverse mutations technique, feature selection, and comparison to other published methods were discussed. Rosetta calculated folding free energy change ranked as the most influential features in all prediction models. Other descriptors also made significant contributions to increasing the accuracy of the prediction models. PMID:26361227

  18. Structure Based Thermostability Prediction Models for Protein Single Point Mutations with Machine Learning Tools

    PubMed Central

    Jia, Lei; Yarlagadda, Ramya; Reed, Charles C.

    2015-01-01

    Thermostability issue of protein point mutations is a common occurrence in protein engineering. An application which predicts the thermostability of mutants can be helpful for guiding decision making process in protein design via mutagenesis. An in silico point mutation scanning method is frequently used to find “hot spots” in proteins for focused mutagenesis. ProTherm (http://gibk26.bio.kyutech.ac.jp/jouhou/Protherm/protherm.html) is a public database that consists of thousands of protein mutants’ experimentally measured thermostability. Two data sets based on two differently measured thermostability properties of protein single point mutations, namely the unfolding free energy change (ddG) and melting temperature change (dTm) were obtained from this database. Folding free energy change calculation from Rosetta, structural information of the point mutations as well as amino acid physical properties were obtained for building thermostability prediction models with informatics modeling tools. Five supervised machine learning methods (support vector machine, random forests, artificial neural network, naïve Bayes classifier, K nearest neighbor) and partial least squares regression are used for building the prediction models. Binary and ternary classifications as well as regression models were built and evaluated. Data set redundancy and balancing, the reverse mutations technique, feature selection, and comparison to other published methods were discussed. Rosetta calculated folding free energy change ranked as the most influential features in all prediction models. Other descriptors also made significant contributions to increasing the accuracy of the prediction models. PMID:26361227

  19. MAPT and PAICE: Tools for time series and single time point transcriptionist visualization and knowledge discovery

    PubMed Central

    Hosseini, Parsa; Tremblay, Arianne; Matthews, Benjamin F; Alkharouf, Nadim W

    2012-01-01

    With the advent of next-generation sequencing, -omics fields such as transcriptomics have experienced increases in data throughput on the order of magnitudes. In terms of analyzing and visually representing these huge datasets, an intuitive and computationally tractable approach is to map quantified transcript expression onto biochemical pathways while employing datamining and visualization principles to accelerate knowledge discovery. We present two cross-platform tools: MAPT (Mapping and Analysis of Pathways through Time) and PAICE (Pathway Analysis and Integrated Coloring of Experiments), an easy to use analysis suite to facilitate time series and single time point transcriptomics analysis. In unison, MAPT and PAICE serve as a visual workbench for transcriptomics knowledge discovery, data-mining and functional annotation. Both PAICE and MAPT are two distinct but yet inextricably linked tools. The former is specifically designed to map EC accessions onto KEGG pathways while handling multiple gene copies, detection-call analysis, as well as UN/annotated EC accessions lacking quantifiable expression. The latter tool integrates PAICE datasets to drive visualization, annotation, and data-mining. Availability The database is available for free at http://sourceforge.net/projects/paice/http://sourceforge.net/projects/mapt/ PMID:22493539

  20. Age-stratified cut-off points for the nocturnal penile tumescence measurement using Nocturnal Electrobioimpedance Volumetric Assessment (NEVA(®) ) in sexually active healthy men.

    PubMed

    Tok, A; Eminaga, O; Burghaus, L; Herden, J; Akbarov, I; Engelmann, U; Wille, S

    2016-08-01

    The current nocturnal penile tumescence (NPT) measurement is based on standard cut-off levels defined regardless of age. This study was conducted to provide age-stratified cut-off points for NPT measurement. Forty sexually active healthy men between 20 and 60 years old were enrolled and divided equally into four groups defined by age (20-29, 30-39, 40-49 and 50-60 years.). None of the candidates had sexual dysfunction or sleep disturbance or used supportive medication to enhance sexual function. Erectile function was evaluated by using the 5-item version of the international index of erectile function (IIEF-5). NPT was observed using the nocturnal electrobioimpedance volumetric assessment (NEVA(®) ). The NPT values of healthy men aged 20-60 years varied from 268.7% to 202.3%. The NPT differed significantly between age groups (P < 0.0009); however, no significant differences between men aged 30-39 and 40-49 (P = 0.593) were observed. Age was weakly associated with IIEF-5 scores (P = 0.004), whereas a strong and negative correlation between age and NPT (P < 0.0001) was found. IEF-5 scores were not significantly associated with NPT (P = 0.95). Therefore, the standard values for NPT testing should be considered in the evaluation of the nocturnal penile activity of men of all ages. PMID:26498135

  1. A Robot Laser As A Flexible Tool For Cutting Openings In The Car-Body On The Production Line

    NASA Astrophysics Data System (ADS)

    Felske, A.; Lunzmann, F.

    1986-11-01

    A flexible laser robot system is described which has been selected for the purpose of cutting additional openings in entire bodies in white on the conveyor. The lightweight CO2 400-W-laser generator is carried and moved computer-controlled by the VOLKSWAGEN robotic system with a fixed 3-mirror robot arm for minimizing losses of energy and for increasing quality and reliability. In a pilot project this technique is integrated in the production line at a final stage of production and can be started with the designation of the vehicle's body.

  2. Stress analysis and design considerations for Shuttle pointed autonomous research tool for astronomy /SPARTAN/

    NASA Technical Reports Server (NTRS)

    Ferragut, N. J.

    1982-01-01

    The Shuttle Pointed Autonomous Research Tool for Astronomy (SPARTAN) family of spacecraft are intended to operate with minimum interfaces with the U.S. Space Shuttle in order to increase flight opportunities. The SPARTAN I Spacecraft was designed to enhance structural capabilities and increase reliability. The approach followed results from work experience which evolved from sounding rocket projects. Structural models were developed to do the analyses necessary to satisfy safety requirements for Shuttle hardware. A loads analysis must also be performed. Stress analysis calculations will be performed on the main structural elements and subcomponents. Attention is given to design considerations and program definition, the schematic representation of a finite element model used for SPARTAN I spacecraft, details of loads analysis, the stress analysis, and fracture mechanics plan implications.

  3. PointCloudXplore: a visualization tool for 3D gene expressiondata

    SciTech Connect

    Rubel, Oliver; Weber, Gunther H.; Keranen, Soile V.E.; Fowlkes,Charles C.; Luengo Hendriks, Cristian L.; Simirenko, Lisa; Shah, NameetaY.; Eisen, Michael B.; Biggn, Mark D.; Hagen, Hans; Sudar, Damir J.; Malik, Jitendra; Knowles, David W.; Hamann, Bernd

    2006-10-01

    The Berkeley Drosophila Transcription Network Project (BDTNP) has developed a suite of methods that support quantitative, computational analysis of three-dimensional (3D) gene expression patterns with cellular resolution in early Drosophila embryos, aiming at a more in-depth understanding of gene regulatory networks. We describe a new tool, called PointCloudXplore (PCX), that supports effective 3D gene expression data exploration. PCX is a visualization tool that uses the established visualization techniques of multiple views, brushing, and linking to support the analysis of high-dimensional datasets that describe many genes' expression. Each of the views in PointCloudXplore shows a different gene expression data property. Brushing is used to select and emphasize data associated with defined subsets of embryo cells within a view. Linking is used to show in additional views the expression data for a group of cells that have first been highlighted as a brush in a single view, allowing further data subset properties to be determined. In PCX, physical views of the data are linked to abstract data displays such as parallel coordinates. Physical views show the spatial relationships between different genes' expression patterns within an embryo. Abstract gene expression data displays on the other hand allow for an analysis of relationships between different genes directly in the gene expression space. We discuss on parallel coordinates as one example abstract data view currently available in PCX. We have developed several extensions to standard parallel coordinates to facilitate brushing and the visualization of 3D gene expression data.

  4. Performance evaluation and optimization of a fast tool servo for single point diamond turning machines

    NASA Astrophysics Data System (ADS)

    Miller, Arthur C., Jr.; Cuttino, James F.

    1997-11-01

    This paper describes a new, fast tool servo system designed for fabrication of non-rotationally symmetric components using single point diamond turning machines. A prototype device, designed for flexible interfacing to typical machine tool controllers, will be described along with performance testing data of tilted flat and off-axis conic sections. Evaluation data show that servo produced surfaces have an RMS roughness less than 175 angstroms. Techniques for linearizing the hysteretic effects in the piezoelectric actuator are also discussed. The nonlinear effects due to hysteresis are reduced using a dynamic compensator module in conjunction with a linear controller. The compensator samples the reduced using a dynamic compensator module in conjunction with a linear controller. The compensator samples the hysteretic voltage/displacement relationship in real time and modifies the effective gain accordingly. Simulation results indicate that errors in the performance of the system caused by hysteresis in the system can be compensated and reduced by 90 percent. Experimental implementation results in an 80 percent reduction in the motion error caused by hysteresis, but peak-to-valley errors are limited by side effects from the compensation. The uncompensated servo system demonstrated a peak-to-valley error of less than 0.80 micrometer for an off-axis conic section turned on-axis.

  5. Performance evaluation and optimization of a fast tool servo for single point diamond turning machines

    SciTech Connect

    Miller, A.C. Jr.; Cuttino, J.F.

    1997-08-01

    This paper describes a new, fast tool servo system for fabricating non-rotationally symmetric components using single point diamond turning machines. A prototype, designed for flexible interfacing to typical machine tool controllers, will be described along with performance testing data of tilted flat and off-axis conic sections. Evaluation data show that servo produced surfaces have an rms roughness less than 175 angstroms (2-200 {mu}m spatial filter). Techniques for linearizing the hysteretic effects in the piezoelectric actuator are also discussed. The nonlinear effects due to hysteresis are reduced using a dynamic compensator module in conjunction with a linear controller. The compensator samples the hysteretic voltage/displacement relation in real time and modifies the effective gain accordingly. Simulation results indicate that errors in the performance of the system caused by hysteresis can be compensated and reduced by 90%. Experimental implementation results in 80% reduction in motion error caused by hysteresis, but peak-to- valley errors are limited by side effects from the compensation. The uncompensated servo system demonstrated a peak-to-valley error of less than 0.80 micrometer for an off-axis conic section turned on-axis.

  6. Effect of micro/nano-scale textures on anti-adhesive wear properties of WC/Co-based TiAlN coated tools in AISI 316 austenitic stainless steel cutting

    NASA Astrophysics Data System (ADS)

    Zhang, Kedong; Deng, Jianxin; Sun, Jialin; Jiang, Chao; Liu, Yayun; Chen, Shuai

    2015-11-01

    In cutting of stainless steel with coated tool, the steel chip adhering to tool surface is usually severe and consequently causes serious adhesive and frictional problems, which is the major reason for the failure of coated tool. To solve the problem, a surface engineering approach, namely, a highly functionalization of tool surfaces by textures may be of great importance. Thus, the effect of micro/nano-scale textures on anti-adhesive wear properties of TiAlN coated tools in AISI 316 austenitic stainless steel cutting was investigated. For this purpose, two types of surface textures were fabricated on the rake faces of WC/Co carbide tools: (i) micro-scale textures fabricated by Nd:YAG laser, (ii) micro/nano-scales textures fabricated by Nd:YAG laser and femtosecond laser. Then, these textured tools were deposited with TiAlN coatings using cathode arc-evaporation technique. Wet cutting experiments were carried out with the micro-scale textured coated tool (MCT), micro/nano-scale textured coated tool (MNCT), and the conventional coated tool (CCT). Results obtained in this work demonstrated the feasibility of fabricating micro- or micro/nano-scale textures on tools substrate surfaces to improve the anti-adhesive wear properties of TiAlN coated tool. The rake face micro/nano-scale textured tool was the most effective. Moreover, mechanisms for the anti-adhesive properties enhancement were proposed.

  7. Operationalizing hippocampal volume as an enrichment biomarker for amnestic MCI trials: effect of algorithm, test-retest variability and cut-point on trial cost, duration and sample size

    PubMed Central

    Yu, P.; Sun, J.; Wolz, R.; Stephenson, D.; Brewer, J.; Fox, N.C.; Cole, P.E.; Jack, C.R.; Hill, D.L.G.; Schwarz, A.J.

    2014-01-01

    Objective To evaluate the effect of computational algorithm, measurement variability and cut-point on hippocampal volume (HCV)-based patient selection for clinical trials in mild cognitive impairment (MCI). Methods We used normal control and amnestic MCI subjects from ADNI-1 as normative reference and screening cohorts. We evaluated the enrichment performance of four widely-used hippocampal segmentation algorithms (FreeSurfer, HMAPS, LEAP and NeuroQuant) in terms of two-year changes in MMSE, ADAS-Cog and CDR-SB. We modeled the effect of algorithm, test-retest variability and cut-point on sample size, screen fail rates and trial cost and duration. Results HCV-based patient selection yielded not only reduced sample sizes (by ~40–60%) but also lower trial costs (by ~30–40%) across a wide range of cut-points. Overall, the dependence on the cut-point value was similar for the three clinical instruments considered. Conclusion These results provide a guide to the choice of HCV cut-point for aMCI clinical trials, allowing an informed trade-off between statistical and practical considerations. PMID:24211008

  8. Beyond Jeopardy and Lectures: Using "Microsoft PowerPoint" as a Game Design Tool to Teach Science

    ERIC Educational Resources Information Center

    Siko, Jason; Barbour, Michael; Toker, Sacip

    2011-01-01

    To date, research involving homemade PowerPoint games as an instructional tool has not shown statistically significant gains in student performance. This paper examines the results of a study comparing the performance of students in a high school chemistry course who created homemade PowerPoint games as a test review with the students who used a…

  9. A survey of ground operations tools developed to simulate the pointing of space telescopes and the design for WISE

    NASA Technical Reports Server (NTRS)

    Fabinsky, Beth

    2006-01-01

    WISE, the Wide Field Infrared Survey Explorer, is scheduled for launch in June 2010. The mission operations system for WISE requires a software modeling tool to help plan, integrate and simulate all spacecraft pointing and verify that no attitude constraints are violated. In the course of developing the requirements for this tool, an investigation was conducted into the design of similar tools for other space-based telescopes. This paper summarizes the ground software and processes used to plan and validate pointing for a selection of space telescopes; with this information as background, the design for WISE is presented.

  10. Material for Fast Cutting

    NASA Technical Reports Server (NTRS)

    Perez, A.

    1986-01-01

    New material for cutting tools increases productivity of machining processes. Material, called Iscanite (or equivalent), based on silicon nitride contains more than 90 percent silicon. Combines impact resistance close to that of coated carbides with heat and wear resistance close to those of aluminum oxide ceramics. Material used for cutting on old or new machine tools and makes it possible to exploit fully power and speed of machine.