WorldWideScience

Sample records for sliding contact fingers

  1. Measuring contact area in a sliding human finger-pad contact.

    Science.gov (United States)

    Liu, X; Carré, M J; Zhang, Q; Lu, Z; Matcher, S J; Lewis, R

    2018-02-01

    The work outlined in this paper was aimed at achieving further understanding of skin frictional behaviour by investigating the contact area between human finger-pads and flat surfaces. Both the static and the dynamic contact areas (in macro- and micro-scales) were measured using various techniques, including ink printing, optical coherence tomography (OCT) and Digital Image Correlation (DIC). In the studies of the static measurements using ink printing, the experimental results showed that the apparent and the real contact area increased with load following a piecewise linear correlation function for a finger-pad in contact with paper sheets. Comparisons indicated that the OCT method is a reliable and effective method to investigate the real contact area of a finger-pad and allow micro-scale analysis. The apparent contact area (from the DIC measurements) was found to reduce with time in the transition from the static phase to the dynamic phase while the real area of contact (from OCT) increased. The results from this study enable the interaction between finger-pads and contact object surface to be better analysed, and hence improve the understanding of skin friction. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Rough viscoelastic sliding contact: Theory and experiments

    Science.gov (United States)

    Carbone, G.; Putignano, C.

    2014-03-01

    In this paper, we show how the numerical theory introduced by the authors [Carbone and Putignano, J. Mech. Phys. Solids 61, 1822 (2013), 10.1016/j.jmps.2013.03.005] can be effectively employed to study the contact between viscoelastic rough solids. The huge numerical complexity is successfully faced up by employing the adaptive nonuniform mesh developed by the authors in Putignano et al. [J. Mech. Phys. Solids 60, 973 (2012), 10.1016/j.jmps.2012.01.006]. Results mark the importance of accounting for viscoelastic effects to correctly simulate the sliding rough contact. In detail, attention is, first, paid to evaluate the viscoelastic dissipation, i.e., the viscoelastic friction. Fixed the sliding speed and the normal load, friction is completely determined. Furthermore, since the methodology employed in the work allows to study contact between real materials, a comparison between experimental outcomes and numerical prediction in terms of viscoelastic friction is shown. The good agreement seems to validate—at least partially—the presented methodology. Finally, it is shown that viscoelasticity entails not only the dissipative effects previously outlined, but is also strictly related to the anisotropy of the contact solution. Indeed, a marked anisotropy is present in the contact region, which results stretched in the direction perpendicular to the sliding speed. In the paper, the anisotropy of the deformed surface and of the contact area is investigated and quantified.

  3. A finger-shaped tactile sensor for fabric surfaces evaluation by 2-dimensional active sliding touch.

    Science.gov (United States)

    Hu, Haihua; Han, Yezhen; Song, Aiguo; Chen, Shanguang; Wang, Chunhui; Wang, Zheng

    2014-03-11

    Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF) film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT) is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA) is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM). The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures.

  4. Non-contact finger vein acquisition system using NIR laser

    Science.gov (United States)

    Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

    2009-02-01

    Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

  5. Sliding Window-Based Region of Interest Extraction for Finger Vein Images

    Science.gov (United States)

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-01-01

    Region of Interest (ROI) extraction is a crucial step in an automatic finger vein recognition system. The aim of ROI extraction is to decide which part of the image is suitable for finger vein feature extraction. This paper proposes a finger vein ROI extraction method which is robust to finger displacement and rotation. First, we determine the middle line of the finger, which will be used to correct the image skew. Then, a sliding window is used to detect the phalangeal joints and further to ascertain the height of ROI. Last, for the corrective image with certain height, we will obtain the ROI by using the internal tangents of finger edges as the left and right boundary. The experimental results show that the proposed method can extract ROI more accurately and effectively compared with other methods, and thus improve the performance of finger vein identification system. Besides, to acquire the high quality finger vein image during the capture process, we propose eight criteria for finger vein capture from different aspects and these criteria should be helpful to some extent for finger vein capture. PMID:23507824

  6. Boundary lubrication of glass: rubber sliding contacts

    NARCIS (Netherlands)

    Heide, E. van der; Lossie, C.M.; Bommel, K.J.C. van; Reinders, S.A.F.; Lenting, H.B.M.

    2009-01-01

    Polymer brush coatings represent a promising class of coatings for friction control [1], especially in a humid environment [2]. A study on the feasibility of a specific class of polymer brush coatings [5] was done for a sliding system that involves ‘silicon skin L7350’: a silicon rubber used by FIFA

  7. Sliding force measurements of the LHC RF contact Plug In Modules at 15 K and in UHV

    CERN Document Server

    Artoos, K; Renaglia, T; CERN. Geneva. TS Department

    2008-01-01

    Some sliding RF contacts mounted in the Plug In Modules in the LHC interconnects failed during a thermal cycle between 4.2 K and room temperature. Some of the gold-coated copper-beryllium RF fingers buckled during the warm up of the machine, indicating that one or more parameters during operation (e.g. the friction coefficient) could be different from what was used in the calculations. This report describes the measurement of the longitudinal forces acting on the sliding RF fingers at operating vacuum and temperatures.

  8. Sliding force measurements on the LHC RF contact Plug In Modules at 15 K and in UHV

    CERN Document Server

    Artoos, K; Renaglia, T

    2008-01-01

    Some sliding RF contacts mounted in the Plug In Modules in the LHC interconnects failed during a thermal cycle between 4.2 K and room temperature. Gold-coated copperberyllium RF fingers buckled during the warm up of the machine, indicating that one or more parameters during operation (e.g. the friction coefficient under vacuum) could be different from what was used in the calculations. This report describes the measurement of the longitudinal forces acting on the sliding RF fingers at operating vacuum and temperatures.

  9. Sliding friction: From microscopic contacts to Amontons’ law

    OpenAIRE

    Weber, B.A.

    2017-01-01

    Most engineers describe sliding friction using the friction coefficient, the ratio of frictional force to normal force. While this proportionality is very simple, its origin is not trivial at all and has been subject of investigation for more than a century. The current consensus is that both frictional and normal force are proportional to the 'real contact area'. Surface roughness prevents surfaces from coming into full contact; the real contact area is simply the fraction of the apparent co...

  10. Sliding contact fracture of dental ceramics: Principles and validation

    Science.gov (United States)

    Ren, Linlin; Zhang, Yu

    2014-01-01

    Ceramic prostheses are subject to sliding contact under normal and tangential loads. Accurate prediction of the onset of fracture at two contacting surfaces holds the key to greater long-term performance of these prostheses. In this study, building on stress analysis of Hertzian contact and considering fracture criteria for linear elastic materials, a constitutive fracture mechanics relation was developed to incorporate the critical fracture load with the contact geometry, coefficient of friction and material fracture toughness. Critical loads necessary to cause fracture under a sliding indenter were calculated from the constitutive equation, and compared with the loads predicted from elastic stress analysis in conjunction with measured critical load for frictionless normal contact—a semi-empirical approach. The major predictions of the models were calibrated with experimentally determined critical loads of current and future dental ceramics after contact with a rigid spherical slider. Experimental results conform with the trends predicted by the models. PMID:24632538

  11. Surface charging, discharging and chemical modification at a sliding contact

    DEFF Research Database (Denmark)

    Singh, Shailendra Vikram; Kusano, Yukihiro; Morgen, Per

    2012-01-01

    Electrostatic charging, discharging, and consequent surface modification induced by sliding dissimilar surfaces have been studied. The surface-charge related phenomena were monitored by using a home-built capacitive, non-contact electrical probe, and the surface chemistry was studied by X...... are also able to comment on the behavior and the charge decay time in the ambient air-like condition, once the sliding contact is discontinued. XPS analysis showed a marginal deoxidation effect on the polyester disks due to the charging and discharging of the surfaces. Moreover, these XPS results clearly...

  12. Dynamic strain measurements in a sliding microstructured contact

    International Nuclear Information System (INIS)

    Bennewitz, Roland; David, Jonathan; Lannoy, Charles-Francois de; Drevniok, Benedict; Hubbard-Davis, Paris; Miura, Takashi; Trichtchenko, Olga

    2008-01-01

    A novel experiment is described which measures the tangential strain development across the contact between a PDMS (polydimethylsiloxane) block and a glass surface during the initial stages of sliding. The surface of the PDMS block has been microfabricated to take the form of a regular array of pyramidal tips at 20 μm separation. Tangential strain is measured by means of light scattering from the interface between the block and surface. Three phases are observed in all experiments: initial shear deformation of the whole PDMS block, a pre-sliding tangential compression of the tip array with stepwise increase of the compressive strain, and sliding in stick-slip movements as revealed by periodic variation of the strain. The stick-slip sliding between the regular tip array and the randomly rough counter surface always takes on the periodicity of the tip array. The fast slip can cause either a sudden increase or a sudden decrease in compressive strain

  13. Relationship between the real contact area and contact force in pre-sliding regime

    International Nuclear Information System (INIS)

    Song Baojiang; Yan Shaoze

    2017-01-01

    The pre-sliding regime is typically neglected in the dynamic modelling of mechanical systems. However, the change in contact state caused by static friction may decrease positional accuracy and control precision. To investigate the relationship between contact status and contact force in pre-sliding friction, an optical experimental method is presented in this paper. With this method, the real contact state at the interface of a transparent material can be observed based on the total reflection principle of light by using an image processing technique. A novel setup, which includes a pair of rectangular trapezoidal blocks, is proposed to solve the challenging issue of accurately applying different tangential and normal forces to the contact interface. The improved Otsu’s method is used for measurement. Through an experimental study performed on polymethyl methacrylate (PMMA), the quantity of contact asperities is proven to be the dominant factor that affects the real contact area. The relationship between the real contact area and the contact force in the pre-sliding regime is studied, and the distribution of static friction at the contact interface is qualitatively discussed. New phenomena in which the real contact area expands along with increasing static friction are identified. The aforementioned relationship is approximately linear at the contact interface under a constant normal pressure, and the distribution of friction stress decreases from the leading edge to the trailing edge. (paper)

  14. Feasible homopolar dynamo with sliding liquid-metal contacts

    OpenAIRE

    Priede, Jānis; Avalos-Zúñiga, Raúl

    2013-01-01

    We present a feasible homopolar dynamo design consisting of a flat, multi-arm spiral coil, which is placed above a fast-spinning metal ring and connected to the latter by sliding liquid-metal electrical contacts. Using a simple, analytically solvable axisymmetric model, we determine the optimal design of such a setup. For small contact resistance, the lowest magnetic Reynolds number, Rm~34.6, at which the dynamo can work, is attained at the optimal ratio of the outer and inner radii of the ri...

  15. Sand Particles Impact on the Tribological Behavior of Sliding Contact

    Directory of Open Access Journals (Sweden)

    Aldajah Saud

    2016-01-01

    Full Text Available Lubricant contaminants cause severe problems to machines. Substantial research has been conducted to study the impact of such contaminates on the tribological performance of lubricated contacts. The primary goal of such studies is to find solutions to avoid the dirtiest cause of damaging machines’ parts and to reduce energy consumption and maintenance costs. The current study investigates the tribological behavior of contaminated lubricated contacts; the contaminants considered in this research are sand particles. The effect of the sand particles concentration levels on friction and wear of a tribological system under sliding contact was studied. Three different concentration levels were tested; 5%, 10% and 15%.The experimental program was carried out using an in-house built ball on disc machine at room temperature, constant normal load, constant speed, constant running time and constant travelling distance. Results showed that both friction coefficient and wear volume of the contacting surfaces are dependent on the concentration level of the sand particles. Both friction coefficient and wear volume increased by increasing the sand particles concentration. SEM was utilized to study the wear mechanisms of the contacting surfaces, it was found that the dominant wear mechanism in all cases was abrasive wear.

  16. Feasible homopolar dynamo with sliding liquid-metal contacts

    International Nuclear Information System (INIS)

    Priede, Jānis; Avalos-Zúñiga, Raúl

    2013-01-01

    We present a feasible homopolar dynamo design consisting of a flat, multi-arm spiral coil, which is placed above a fast-spinning metal ring and connected to the latter by sliding liquid-metal electrical contacts. Using a simple, analytically solvable axisymmetric model, we determine the optimal design of such a setup. For small contact resistance, the lowest magnetic Reynolds number, Rm≈34.6, at which the dynamo can work, is attained at the optimal ratio of the outer and inner radii of the rings R i /R o ≈0.36 and the spiral pitch angle 54.7°. In a setup of two copper rings with the thickness of 3 cm, R i =10 cm and R o =30 cm, self-excitation of the magnetic field is expected at a critical rotation frequency around 10 Hz

  17. The contact area and sliding friction in nanotribological systems

    International Nuclear Information System (INIS)

    Wolloch, M.

    2014-01-01

    cut to the vacuum, resulting in surface atoms of finite size. In our proposed method the parameter ρ cut is calculated by allowing contact only after the 'jump to contact', or a similar discontinuity, has taken place, which can be clearly observed in our DFT simulations. We demonstrate the method by lowering a ten atom tungsten pyramid, which serves as a model of an AFM tip, onto a smooth surface. Two systems are examined, the first being moiré graphene on iridium (111), the second a clean copper (111) surface. Although the surfaces are very different, a similiar cutoff parameter ρ cut of about 5 x 10 -2 electrons per Å 3 is computed in both cases. The calculated area of contact is found to increase linearly with lowering of the tip support while increasing exponentially with the true relaxed distance between the tip apex atom and the surface atom below it. Although there exist a number of models that tackle the problem of calculating friction forces on the atomic level, providing a completely parameter-free approach remains a challenge. To examine the direction dependence of dry sliding friction we developed a quasi-static grid method with a mechanism to allow dissipative sliding, which relies on atomic relaxations. We define two different ways of calculating the mean nanofriction force, both leading to an exponential friction-versus-load behavior for all sliding directions. Since our approach does not impose any limits on lengths and directions of the sliding paths, we investigate arbitrary sliding directions for several metal interfaces and detect two periodic paths which form the upper and lower bound of nanofriction in all cases. For long aperiodic paths the friction force convergences to a value in between these limits. For low loads we retrieve the Derjaguin generalization of the Amontons-Coulomb kinetic friction law which appears to be valid all the way down to the nanoscale. We observe a non-vanishing Derjaguin-offset even for atomically flat

  18. Pulsed Laser Deposition of Carbide Coatings for Rolling and Sliding Contact Applications

    National Research Council Canada - National Science Library

    Krzanowski, James

    2003-01-01

    In this research program several new concepts were investigated for improving the mechanical and tribological properties of coatings intended for applications subject to repeated rolling and sliding contacts...

  19. A General Contact Force Analysis of an Under-Actuated Finger in Robot Hand Grasping

    Directory of Open Access Journals (Sweden)

    Xuan Vinh Ha

    2016-02-01

    Full Text Available This paper develops a mathematical analysis of contact forces for the under-actuated finger in a general under-actuated robotic hand during grasping. The concept of under-actuation in robotic grasping with fewer actuators than degrees of freedom (DOF, through the use of springs and mechanical limits, allows the hand to adjust itself to an irregularly shaped object without complex control strategies and sensors. Here the main concern is the contact forces, which are important elements in grasping tasks, based on the proposed mathematical analysis of their distributions of the n-DOF under-actuated finger. The simulation results, along with the 3-DOF finger from the ADAMS model, show the effectiveness of the mathematical analysis method, while comparing them with the measured results. The system can find magnitudes of the contact forces at the contact positions between the phalanges and the object.

  20. Sliding friction : From microscopic contacts to Amontons’ law

    NARCIS (Netherlands)

    Weber, B.A.

    2017-01-01

    Most engineers describe sliding friction using the friction coefficient, the ratio of frictional force to normal force. While this proportionality is very simple, its origin is not trivial at all and has been subject of investigation for more than a century. The current consensus is that both

  1. Hydrophobins as aqueous lubricant additive for a soft sliding contact

    DEFF Research Database (Denmark)

    Lee, Seunghwan; Røn, Troels; Pakkanen, Kirsi I.

    2015-01-01

    lubrication characteristic is dominant via ‘self-healing’ mechanism. FpHYD5 revealed a better lubrication than HFBI presumably due to the presence of glycans and improved hydration of the sliding interface. Two type II hydrophobins function more favorably compared to a synthetic amphiphilic copolymer, PEO-PPO...

  2. CRITICAL VELOCITY OF CONTROLLABILITY OF SLIDING FRICTION BY NORMAL OSCILLATIONS IN VISCOELASTIC CONTACTS

    Directory of Open Access Journals (Sweden)

    Mikhail Popov

    2016-12-01

    Full Text Available Sliding friction can be reduced substantially by applying ultrasonic vibration in the sliding plane or in the normal direction. This effect is well known and used in many applications ranging from press forming to ultrasonic actuators. One of the characteristics of the phenomenon is that, at a given frequency and amplitude of oscillation, the observed friction reduction diminishes with increasing sliding velocity. Beyond a certain critical sliding velocity, there is no longer any difference between the coefficients of friction with or without vibration. This critical velocity depends on material and kinematic parameters and is a key characteristic that must be accounted for by any theory of influence of vibration on friction. Recently, the critical sliding velocity has been interpreted as the transition point from periodic stick-slip to pure sliding and was calculated for purely elastic contacts under uniform sliding with periodic normal loading. Here we perform a similar analysis of the critical velocity in viscoelastic contacts using a Kelvin material to describe viscoelasticity. A closed-form solution is presented, which contains previously reported results as special cases. This paves the way for more detailed studies of active control of friction in viscoelastic systems, a previously neglected topic with possible applications in elastomer technology and in medicine.

  3. The study of sliding contact in railgun with metal armature

    International Nuclear Information System (INIS)

    Kondratenko, A.K.; Bykov, M.A.; Schastnykh, B.S.; Glinov, A.P.; Poltanov, A.E.

    1997-01-01

    An experimental technique for the study of the current distribution in the rails and a moving metal armature is developed. The work was carried out on a special experimental railgun with a capacitor power supply. The set of small dB/dt probes as well as wire contact probes were arranged in close vicinity of the rail and armature contact surface. For interpretation of dB/dt measurements the computation technique and program of restoration of current density distribution along the armature was developed. The size and the location of the current concentration zone in the contact area are obtained for several combinations of rail and armature materials; bronze and copper rails, Al and Ti alloy armature. A stationary armature tests with resistive stainless steel and graphite layers were also made to estimate the influence of the layer material resistivity on the current distribution

  4. Differences in finger skin contact cooling response between an arterial occlusion and a vasodilated condition.

    Science.gov (United States)

    Jay, Ollie; Havenith, George

    2006-05-01

    To assess the presence and magnitude of the effect of skin blood flow on finger skin cooling on contact with cold objects against the background of circulatory disorder risks in occupational exposures, this study investigates the effect of zero vs. close-to-maximal hand blood flow on short-term (cooling response at a contact pressure that allows capillary perfusion of the distal pulp of the fingertip. Six male volunteers touched a block of aluminium with a finger contact force of 0.5 N at a temperature of -2 degrees C under a vasodilated and an occluded condition. Before both conditions, participants were required to exercise in a hot room for > or = 30 min for cutaneous vasodilation to occur (increase in rectal temperature of 1 degrees C). Under the vasodilated condition, forearm blood flow rate rose as high as 16.8 ml.100 ml(-1).min(-1). Under the occluded condition, the arm was exsanguinated, after which a blood pressure cuff was secured on the wrist inducing arterial occlusion. Contact temperature of the finger pad during the subsequent cold contact exposure was measured. No significant difference was found between the starting skin temperatures for the two blood flow conditions, but a distinct difference in shape of the contact cooling curve was apparent between the two blood flow conditions, with Newtonian cooling observed under the occluded condition, whereas a rewarming of the finger skin toward the end of the exposure occurred for the vasodilated condition. Blood flow was found to significantly increase contact temperature from 40 s onward (P cooling during a vasodilated state.

  5. Flexor origin slide for contracture of spastic finger flexor muscles: a retrospective study.

    Science.gov (United States)

    Thevenin-Lemoine, Camille; Denormandie, Philippe; Schnitzler, Alexis; Lautridou, Christine; Allieu, Yves; Genêt, François

    2013-03-06

    Contracture of the wrist and extrinsic finger flexor and pronator muscles is a common consequence of central nervous system disorders. The proximal release of the extrinsic flexor and pronator muscles was first described by Page and Scaglietti for a Volkmann contracture. The aim of the present study was to assess the amount of increase in extension and the improvements in global hand function that can be expected following this lengthening procedure in patients with central nervous system disorders. A single-center retrospective review of patients with central nervous system lesions and contractures of the wrist and extrinsic finger flexor and forearm pronator muscles, causing aesthetic, hygienic, or functional impairment, was carried out. The Page-Scaglietti technique was used for all interventions. Before the operation, motor nerve blocks were used to distinguish between spasticity and contractures with surgical intervention only for contractures. The Zancolli and House classifications were used to evaluate improvements. Data from fifty-four hands and fifty patients (thirty-five men and fifteen women) were evaluated. The mean duration of follow-up (and standard deviation) was 26 ± 21 months (range, three to 124 months). The mean gain (and standard deviation) in wrist extension with fingers extended was 67° ± 25° (range, -10° to 110°). Preoperatively, no hands were classified as Zancolli Group 1, whereas twenty-five hands were classified as Zancolli Group 1 at the latest follow-up review. Ten nonfunctional hands (rated as House Group 0 or Group 1) became functional as a supporting hand postoperatively. Zancolli and House classifications increased significantly (p contracture of the intrinsic muscles, which required further intervention. The Page-Scaglietti technique appears to improve range of motion and function in people with wrist and finger contractures due to central nervous system disorders.

  6. Sliding contact loading enhances the tensile properties of mesenchymal stem cell-seeded hydrogels

    Directory of Open Access Journals (Sweden)

    AH Huang

    2012-07-01

    Full Text Available The primary goal of cartilage tissue engineering is to recapitulate the functional properties and structural features of native articular cartilage. While there has been some success in generating near-native compressive properties, the tensile properties of cell-seeded constructs remain poor, and key features of cartilage, including inhomogeneity and anisotropy, are generally absent in these engineered constructs. Therefore, in an attempt to instill these hallmark properties of cartilage in engineered cell-seeded constructs, we designed and characterized a novel sliding contact bioreactor to recapitulate the mechanical stimuli arising from physiologic joint loading (two contacting cartilage layers. Finite element modeling of this bioreactor system showed that tensile strains were direction-dependent, while both tensile strains and fluid motion were depth-dependent and highest in the region closest to the contact surface. Short-term sliding contact of mesenchymal stem cell (MSC-seeded agarose improved chondrogenic gene expression in a manner dependent on both the axial strain applied and transforming growth factor-β supplementation. Using the optimized loading parameters derived from these short-term studies, long-term sliding contact was applied to MSC-seeded agarose constructs for 21 d. After 21 d, sliding contact significantly improved the tensile properties of MSC-seeded constructs and elicited alterations in type II collagen and proteoglycan accumulation as a function of depth; staining for these matrix molecules showed intense localization in the surface regions. These findings point to the potential of sliding contact to produce engineered cartilage constructs that begin to recapitulate the complex mechanical features of the native tissue.

  7. [Comparison of Bacteria ERIC-PCR Fingerprints of Index Fingers and Contactants].

    Science.gov (United States)

    Liu, Y T; Sun, D M; Shi, S P; Yang, X

    2018-02-01

    To explore the bacteria relevance between index fingers and contactant' surfaces (mobile phone touch screen and desktop of personal office table). Bacteria were collected from the index fingers, mobile phone touch screen and desktop of personal office table of 10 volunteers. Enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprint was established by PCR amplification technique of metagenome. There were 7 volunteers' ERIC-PCR fingerprints of index fingers matched that took from the mobile phone touch screens, and different from each other. There were 3 volunteers' ERIC-PCR fingerprints of index fingers matched that took from desk top of personal office table, and other 7 volunteers' ERIC-PCR fingerprints did not match perfectly with that took from desk top of personal office table, but had at least one similar band for both. The bacteria on index finger shows individual specificity, which on mobile phone touching screen and personal desktop may be a new biological sample of forensic identification. Copyright© by the Editorial Department of Journal of Forensic Medicine.

  8. Fatigue and Wear in Rolling and Sliding Contacts

    DEFF Research Database (Denmark)

    Janakiraman, Shravan

    bearing supports the main shaft, which connects the rotor to thegearbox. The main bearing is a rolling element bearing containing sphericalrolling elements. The loads on a main bearings are very high, which leads toa lubrication regime called elastohydrodynamic lubrication (EHL). Under theEHL regime...... to increase the film thickness, so as to ensure there is no contactbetween the roller and the raceway. Under lower loads (loads less than EHLloads) it has been observed that axial grooves help to increase the film thicknessat certain optimum operating conditions. It is believed that these groovesact...... the filmthickness. They might improve the film thickness at certain optimum runningconditions, but it is tough to ascertain what those conditions are.The main bearings also undergo rolling contact fatigue failure. The main bearingsexperience premature fatigue failure in both onshore and offshore windturbines...

  9. A sliding point contact model for the finite element structures code EURDYN

    International Nuclear Information System (INIS)

    Smith, B.L.

    1986-01-01

    A method is developed by which sliding point contact between two moving deformable structures may be incorporated within a lumped mass finite element formulation based on displacements. The method relies on a simple mechanical interpretation of the contact constraint in terms of equivalent nodal forces and avoids the use of nodal connectivity via a master slave arrangement or pseudo contact element. The methodology has been iplemented into the EURDYN finite element program for the (2D axisymmetric) version coupled to the hydro code SEURBNUK. Sample calculations are presented illustrating the use of the model in various contact situations. Effects due to separation and impact of structures are also included. (author)

  10. Dealing with friction in a reusable 6 degrees of freedom adjustment mechanism with sliding contacts

    NARCIS (Netherlands)

    Klinkhamer, J.F.F.

    2003-01-01

    Although the possibility of a 6 degrees of freedom adjustment based on a single body pulled onto on six adjustable supports follows directly from the kinematic theory, such mechanisms are seldom used in actual products. Two major drawbacks for the use of this solution are: Due to the sliding contact

  11. Physical essence of the multibody contact-sliding at atomic scale

    Science.gov (United States)

    Han, Xuesong

    2014-01-01

    Investigation the multibody contact-sliding occurred at atomic discrete contact spot will play an important role in determine the origin of tribology behavior and evaluates the micro-mechanical property of nanomaterials and thus optimizing the design of surface texture. This paper carries out large scale parallel molecular dynamics simulation on contact-sliding at atomic scale to uncover the special physical essence. The research shows that some kind of force field exists between nanodot pair and the interaction can be expressed by the linear combination of exponential function while the effective interaction distance limited in 1 angstrom for nanodot with several tens of nanometer diameter. The variation tendency about the interaction force between nanodot array is almost the same between nanodot pairs and thus the interaction between two nanodot array can be characterized by parallel mechanical spring. Multibody effect which dominates the interaction between atoms or molecules will gradually diminish with the increasing of length scales.

  12. Failure mechanism of coated biomaterials under high impact-sliding contact stresses

    Science.gov (United States)

    Chen, Ying

    This study uses a newly developed testing method--- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose was accomplished in the three stages: First, impact-sliding test was carried out on TiN coated unhardened M2. It was found that soft substrate can cause early failure of coating due to the considerable plastic deformation in the substrate. In this case, stronger substrate is required to support coating better when tested under high contact stresses. Second, PEO coated Ti-6Al-4V was tested under pure sliding and impact-sliding wear conditions. PEO coating was found not strong enough to afford the high contact pressure under cyclic impact-sliding wear test due to its porous surface structure. However, the wear performance of PEO coating was enhanced due to the sub-stoichiometric oxide. To sum up, for load-bearing biomedical implants involved in high impacting movement, PEO coating may not be a promising surface protection. Third, the dense, smooth PVD/CVD bio-inert coatings were reconsidered. DLC and TiN coatings, combined by different substrates together with different interface materials were tested under the cyclic impact-sliding test using a set of proper loading. The results show that to choose a proper combination of coating, interface and substrate based on their mechanical properties is of great importance under the test condition. Hard substrates provide support

  13. Elastomers in Combined Rolling-Sliding Contact; Wear and its Underlying Mechanisms

    Science.gov (United States)

    Rowe, Kyle Gene

    Elastomeric materials, specifically rubbers, being both of a practical and scientific importance, have been the subjects of vast amounts of research spanning well over two centuries. There is currently a large effort by tire manufacturers to design new rubber compounds with lower rolling resistance, higher sliding friction, and reduced or predictable wear. At present, these efforts are primarily based on a few empirical rules and very costly trial and error testing; only a basic understanding of the mechanisms involved in the wear of elastomeric materials exists despite rigorous study. In general, the only well controlled experiments have been for simple loading and sliding schemes. The aim of this work is to characterize the tribological properties of a carbon black filled natural rubber sample. This work explores (1) its behavior in unidirectional sliding, (2) contact mechanics, (3) traction properties in combined rolling and sliding, (4) frictional heating response, and (5) wear. It was found that the friction coefficient of this material was dependent upon sliding velocity, contact pressure, and surface roughness. The high friction coefficients also lead to a bifurcation of the contact area into two different pressure regimes at sliding velocities greater than 10 mm/s . The traction response of this material in combined rolling and sliding exhibited similar behavior, being a function of the contact pressure, but not rolling velocity. The wear of this material was found to be linearly dependent upon the global slip condition and occurred preferentially on the sample. Investigations of the worn surface revealed that the most likely mechanism of wear is the degradation of surface material in a confined layer a few micrometers thick. A simple spring-mass model was developed to offer an explanation of localized wear. It was found that the coupling of system elements in the normal direction helped to shift the load from wearing elements to non-wearing ones. The

  14. Tribological characteristic enhancement effects by polymer thickened oil in lubricated sliding contacts

    Science.gov (United States)

    Pratomo, Ariawan Wahyu; Muchammad, Tauviqirrahman, Mohammad; Jamari, Bayuseno, Athanasius P.

    2016-04-01

    Polymer thickened oils are the most preferred materials for modern lubrication applications due to their high shear. The present paper explores a lubrication mechanism in sliding contact lubricated with polymer thickened oil considering cavitation. Investigations are carried out by using a numerical method based on commercial CFD (computational fluid dynamic) software ANSYS for fluid flow phenomenon (Fluent) to assess the tribological characteristic (i.e. hydrodynamic pressure distribution) of lubricated sliding contact. The Zwart-Gerber-Belamri model for cavitation is adopted in this simulation to predict the extent of the full film region. The polymer thickened oil is characterized as non-Newtonian power-law fluid. The simulation results show that the cavitation lead lower pressure profile compared to that without cavitation. In addition, it is concluded that the characteristic of the lubrication performance with polymer thickened oil is strongly dependent on the Power-law index of lubricant.

  15. Modular correction method of bending elastic modulus based on sliding behavior of contact point

    International Nuclear Information System (INIS)

    Ma, Zhichao; Zhao, Hongwei; Zhang, Qixun; Liu, Changyi

    2015-01-01

    During the three-point bending test, the sliding behavior of the contact point between the specimen and supports was observed, the sliding behavior was verified to affect the measurements of both deflection and span length, which directly affect the calculation of the bending elastic modulus. Based on the Hertz formula to calculate the elastic contact deformation and the theoretical calculation of the sliding behavior of the contact point, a theoretical model to precisely describe the deflection and span length as a function of bending load was established. Moreover, a modular correction method of bending elastic modulus was proposed, via the comparison between the corrected elastic modulus of three materials (H63 copper–zinc alloy, AZ31B magnesium alloy and 2026 aluminum alloy) and the standard modulus obtained from standard uniaxial tensile tests, the universal feasibility of the proposed correction method was verified. Also, the ratio of corrected to raw elastic modulus presented a monotonically decreasing tendency as the raw elastic modulus of materials increased. (technical note)

  16. Investigation of force, contact area, and dwell time in finger-tapping tasks on membrane touch interface.

    Science.gov (United States)

    Liu, Na; Yu, Ruifeng

    2018-06-01

    This study aimed to determine the touch characteristics during tapping tasks on membrane touch interface and investigate the effects of posture and gender on touch characteristics variables. One hundred participants tapped digits displayed on a membrane touch interface on sitting and standing positions using all fingers of the dominant hand. Touch characteristics measures included average force, contact area, and dwell time. Across fingers and postures, males exerted larger force and contact area than females, but similar dwell time. Across genders and postures, thumb exerted the largest force and the force of the other four fingers showed no significant difference. The contact area of the thumb was the largest, whereas that of the little finger was the smallest; the dwell time of the thumb was the longest, whereas that of the middle finger was the shortest. Relationships among finger sizes, gender, posture and touch characteristics were proposed. The findings helped direct membrane touch interface design for digital and numerical control products from hardware and software perspectives. Practitioner Summary: This study measured force, contact area, and dwell time in tapping tasks on membrane touch interface and examined effects of gender and posture on force, contact area, and dwell time. The findings will direct membrane touch interface design for digital and numerical control products from hardware and software perspectives.

  17. Dynamic Behavior Analysis of Non-Contacting Hydrodynamic Finger Seal Based on Fluid-Solid-Interaction Method

    Directory of Open Access Journals (Sweden)

    Su Hua

    2018-01-01

    Full Text Available Finger seal is an advanced compliant seal and can be utilized to separate high (HP and low pressure (LP zones in high speed rotating shaft environment. The work to be presented concerns the dynamic behavior of a repetitive section of a two-layer finger seal with high-and padded low-pressure laminates. The dynamic performance of the finger seal are analyzed by the coupled fluid-solid-interaction (FSI simulations. By using the commercial software ANSYS-CFX, the numerical simulation results of interactions between the gas flow and fingers structural deformation are described when the radial periodic excitation from the shaft applies to the finger seal. And the gas film loading capacity, gas film stiffness and leakage varied with time are put forward in different working conditions. Compared with the dynamic performance analysis results based on equivalent dynamic method, the FSI dynamic analysis shows some different characteristics which are more accordance with actual circumstance. Moreover, it is shown that under low pressure differential and high rotation speed the non-contacting finger seal with advance features both in sealing effectiveness and potential unlimited life span can be obtained by rational structure design. But for the non-contacting finger seal with circumferential convergent pad working in high pressure and low rotating speed conditions, it is difficult to improve the sealing performance by the way of changing the structure parameters of finger seal. It is because the high pressure plays a major role on this sealing situation.

  18. XPS analysis of the effect of fillers on PTFE transfer film development in sliding contacts

    Science.gov (United States)

    Blanchet, T. A.; Kennedy, F. E.; Jayne, D. T.

    1993-01-01

    The development of transfer films atop steel counterfaces in contact with unfilled and bronze-filled PTFE has been studied using X-ray photoelectron spectroscopy. The sliding apparatus was contained within the vacuum of the analytical system, so the effects of the native oxide, hydrocarbon, and adsorbed gaseous surface layers of the steel upon the PTFE transfer behavior could be studied in situ. For both the filled and the unfilled PTFE, cleaner surfaces promoted greater amounts of transfer. Metal fluorides, which formed at the transfer film/counterface interface, were found solely in cases where the native oxide had been removed to expose the metallic surface prior to sliding. These fluorides also were found at clean metal/PTFE interfaces formed in the absence of frictional contact. A fraction of these fluorides resulted from irradiation damage inherent in XPS analysis. PTFE transfer films were found to build up with repeated sliding passes, by a process in which strands of transfer filled in the remaining counterface area. Under these reported test conditions, the transfer process is not expected to continue atop previously deposited transfer films. The bronze-filled composite generated greater amounts of transfer than the unfilled PTFE. The results are discussed relative to the observed increase in wear resistance imparted to PTFE by a broad range of inorganic fillers.

  19. Sliding three-phase contact line of printed droplets for single-crystal arrays

    International Nuclear Information System (INIS)

    Kuang, Minxuan; Wu, Lei; Li, Yifan; Gao, Meng; Zhang, Xingye; Jiang, Lei; Song, Yanlin

    2016-01-01

    Controlling the behaviours of printed droplets is an essential requirement for inkjet printing of delicate three-dimensional (3D) structures or high-resolution patterns. In this work, molecular deposition and crystallization are regulated by manipulating the three-phase contact line (TCL) behaviour of the printed droplets. The results show that oriented single-crystal arrays are fabricated based on the continuously sliding TCL. Owing to the sliding of the TCL on the substrate, the outward capillary flow within the evaporating droplet is suppressed and the molecules are brought to the centre of the droplet, resulting in the formation of a single crystal. This work provides a facile strategy for controlling the structures of printed units by manipulating the TCL of printed droplets, which is significant for realizing high-resolution patterns and delicate 3D structures. (paper)

  20. Tribochemical interactions of Si-doped DLC film against steel in sliding contact

    International Nuclear Information System (INIS)

    Yoon, Eui Sung; Pham, Duc Cuong; Ahn, Hyo Sok; Oh, Jae Eung

    2007-01-01

    This study concerns the effects of tribochemical interactions at the interface of Si-DLC (silicon-doped diamond-like carbon) film and steel ball in sliding contact on tribological properties of the film. The Si-DLC film was over-coated on pure DLC coating by radio frequency plasma-assisted chemical vapor deposition (r.f. PACVD) with different Si concentration. Friction tests against steel ball using a reciprocating type tribotester were performed in ambient environment. X-Ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) were used to study the chemical characteristics and elemental composition of the films and mating balls after tests. Results showed a darkgray film consisting of carbon, oxygen and silicon on the worn steel ball surface with different thickness. On the contrary, such film was not observed on the surface of the ball slid against pure DLC coating. The oxidation of Si-DLC surface and steel ball was also found at particular regions of contact area. This demonstrates that tribochemical interactions occurred at the contact area of Si-DLC and steel ball during sliding to form a tribofilm (so called transfer film) on the ball specimen. While the pure DLC coating exhibited high coefficient of friction (∼0.06), the Si-DLC film showed a significant lower coefficient of friction (∼0.022) with the presence of tribofilm on mating ball surface. However, the Si-DLC film possesses a very high wear rate in comparison with the pure DLC. It was found that the tribochemical interactions strongly affected tribological properties of the Si-DLC film in sliding against steel

  1. DURABILITY AND TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING IN LUBRICATED ROLLING WITH SLIDING CONTACT

    Directory of Open Access Journals (Sweden)

    Mohammad Ali

    2010-09-01

    Full Text Available Durability and tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally in lubricated rolling with sliding contact conditions. By means of the high energy type flame spraying (Hi-HVOF method, the coating was formed onto the axially ground and circumferentially ground roller specimens made of a thermally refined carbon steel. In the experiments, the WC cermet coated steel roller was mated with the carburized hardened steel roller without coating in line contact condition. The coated roller was mated with the smooth non-coated roller under a contact pressure of 1.0 or 1.2 GPa, and it was mated with the rough non-coated roller under a contact pressure of 0.6 or 0.8 GPa. As a result, it was found that in general, the coating on the circumferentially ground substrate shows a lower durability compared with that on the axially ground substrate and this difference appears more distinctly for the higher contact pressure for both smooth mating surface and rough mating surface. It was also found that there are significant differences in the tribological properties of WC cermet coating depending on the contact pressure. In addition, depending on the smooth or rough mating surface, remarkable differences in the tribological properties were found.

  2. Static and kinetic friction force and surface roughness of different archwire-bracket sliding contacts.

    Science.gov (United States)

    Carrion-Vilches, Francisco J; Bermudez, María-Dolores; Fructuoso, Paula

    2015-01-01

    The aim of this study was to determine the static and kinetic friction forces of the contact bracket-archwire with different dental material compositions in order to select those materials with lower resistance to sliding. We carried out sliding friction tests by means of a universal testing machine following an experimental procedure as described in ASTM D1894 standard. We determined the static and kinetic friction forces under dry and lubricating conditions using an artificial saliva solution at 36.5ºC. The bracket-archwire pairs studied were: stainless steel-stainless steel; stainless steel-glass fiber composite; stainless steel-Nitinol 60; sapphire-stainless steel; sapphire-glass fiber composite; and sapphire-Nitinol 60. The best performance is obtained for Nitinol 60 archwire sliding against a stainless steel bracket, both under dry and lubricated conditions. These results are in agreement with the low surface roughness of Nitinol 60 with respect to the glass fiber composite archwire. The results described here contribute to establishing selection criteria for materials for dental archwire-brackets.

  3. Erosion by sliding wear in granular flows: Experiments with realistic contact forces

    Science.gov (United States)

    Stark, C. P.; Hung, C. Y.; Smith, B.; Li, L.; Grinspun, E.; Capart, H.

    2015-12-01

    Debris flow erosion is a powerful and sometimes dominant process in steep channels. Despite its importance, this phenomenon is relatively little studied in the lab. The large drum experiments of Hsu are a notable exception, in which almost-field-scale impact forces were generated at the head of a synthetic debris flow whose properties (grain size, proportion of fines, etc) were varied widely.A key challenge in these and similar experiments is to explore how erosion rate varies as a function of the scale of the flow (thereby varying inertial stresses, impact forces, etc). The geometrical limitations of most lab experiments, and their short run time, severely limit the scope of such explorations.We achieve this scale exploration in a set of drum erosion experiments by varying effective gravity across several orders of magnitude (1g, 10g, 100g) in a geotechnical centrifuge. By half-filling our 40cm-diameter drum with dry 2.3mm grains, placing a synthetic rock plate at the back and a glass plate at the front 3cm apart, and rotating the drum at 1-50rpm, we simulate wear in a channelized dry granular flow. In contrast to Hsu's experiments, we focus on sliding wear erosion at the flow boundary rather than impact/frictional wear at the flow head. By varying effective gravity from 1g-100g we can tune the pressure exerted by the grains at the boundary without having to change the scale of our apparatus. Using a recently developed depth-averaged, kinetic-energy closure theory for granular flow, we can simultaneously tune the drum rotation rate such that the flow dynamics remain invariant. We can thereby explore how changing the scale of a granular flow, and thus the contact forces of grains on the boundary, controls the rate of rock erosion. Using a small apparatus we can simulate the erosion generated by debris flows several meters deep involving grains up to 10cm in diameter.Our results suggest that sliding wear is the main erosion process, and are consistent with Archard

  4. Transition from steady to periodic liquid-metal magnetohydrodynamic flow in a sliding electrical contact

    Science.gov (United States)

    Talmage, Gita; Walker, John S.; Brown, Samuel H.; Sondergaard, Neal A.

    1993-09-01

    In homopolar motors and generators, large dc electric currents pass through the sliding electrical contacts between rotating copper disks (rotors) and static copper surfaces shrouding the rotor tips (stators). A liquid metal in the small radial gap between the rotor tip and concentric stator surface can provide a low-resistance, low-drag electrical contact. Since there is a strong magnetic field in the region of the electrical contacts, there are large electromagnetic body forces on the liquid metal. The primary, azimuthal motion consists of simple Couette flow, plus an electromagnetically driven flow with large extremes of the azimuthal velocity near the rotor corners. The secondary flow involves the radial and axial velocity components, is driven by the centrifugal force associated with the primary flow, and is opposed by the electromagnetic body force, so that the circulation varies inversely as the square of the magnetic-field strength. Three flow regimes are identified as the angular velocity Ω of the rotor is increased. For small Ω, the primary flow is decoupled from the secondary flow. As Ω increases, the secondary flow begins to convect the azimuthal-velocity peaks radially outward, which in turn changes the centrifugal force driving the secondary flow. At some critical value of Ω, the flow becomes periodic through the coupling of the primary and secondary flows. The azimuthal-velocity peaks begin to move radially in and out with an accompanying oscillation in the secondary-flow strength.

  5. Tribological study on rapeseed oil with nano-additives in close contact sliding situation

    Science.gov (United States)

    Gupta, Rajeev Nayan; Harsha, A. P.; Singh, Sagar

    2018-02-01

    The present work deals with the tribological evaluation of three types of nano-additives, i.e., copper oxide (CuO; ≈ 151.2 nm), cerium oxide (CeO2; ≈ 80 nm) and polytetrafluoroethylene (PTFE; ≈ 90.4 nm) with rapeseed oil under steel-steel sliding contacts. The nano-additives concentrations in the base oil were 0.1, 0.25 and 0.5% w/v for the lubricant formulation. Further, the rapeseed oil was also epoxidized by a chemical method and the tribological behavior was compared with the base oil (unmodified oil) at similar nano-additives concentrations. The ASTM standards were followed for the study of wear preventive and extreme-pressure analysis of nanolubricants, and it was carried out using four-ball tester. In the antiwear test, CeO2 and PTFE nano-additives have shown the significant reduction in the wear scar diameter at the concentration of 0.1% w/v. In the extreme-pressure test, 0.5% w/v concentration was optimum for oxide nanoparticles; however, PTFE nanoparticles did not show positive effect with both the base oils. Different characterization techniques were employed to confirm the oil modification and for the study of the worn surfaces.

  6. Slide 1

    Indian Academy of Sciences (India)

    Table of contents. Slide 1 · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17.

  7. Slide 1

    Indian Academy of Sciences (India)

    Table of contents. Slide 1 · Slide 2 · Membrane Phospholipids · Slide 4 · NAE and NAPE · Biological and Pharmacological properties · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25.

  8. Onset of frictional sliding of rubber-glass contact under dry and lubricated conditions.

    Science.gov (United States)

    Tuononen, Ari J

    2016-06-13

    Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons' law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements.

  9. Acquiring a 2D rolled equivalent fingerprint image from a non-contact 3D finger scan

    Science.gov (United States)

    Fatehpuria, Abhishika; Lau, Daniel L.; Hassebrook, Laurence G.

    2006-04-01

    The use of fingerprints as a biometric is both the oldest mode of computer aided personal identification and the most relied-upon technology in use today. But current fingerprint scanning systems have some challenging and peculiar difficulties. Often skin conditions and imperfect acquisition circumstances cause the captured fingerprint image to be far from ideal. Also some of the acquisition techniques can be slow and cumbersome to use and may not provide the complete information required for reliable feature extraction and fingerprint matching. Most of the difficulties arise due to the contact of the fingerprint surface with the sensor platen. To attain a fast-capture, non-contact, fingerprint scanning technology, we are developing a scanning system that employs structured light illumination as a means for acquiring a 3-D scan of the finger with sufficiently high resolution to record ridge-level details. In this paper, we describe the postprocessing steps used for converting the acquired 3-D scan of the subject's finger into a 2-D rolled equivalent image.

  10. Friction-induced vibrations and self-organization mechanics and non-equilibrium thermodynamics of sliding contact

    CERN Document Server

    Nosonovsky, Michael

    2013-01-01

    Many scientists and engineers do not realize that, under certain conditions, friction can lead to the formation of new structures at the interface, including in situ tribofilms and various patterns. In turn, these structures-usually formed by destabilization of the stationary sliding regime-can lead to the reduction of friction and wear. Friction-Induced Vibrations and Self-Organization: Mechanics and Non-Equilibrium Thermodynamics of Sliding Contact combines the mechanical and thermodynamic methods in tribology, thus extending the field of mechanical friction-induced vibrations to non-mechanical instabilities and self-organization processes at the frictional interface. The book also relates friction-induced self-organization to novel biomimetic materials, such as self-lubricating, self-cleaning, and self-healing materials. Explore Friction from a Different Angle-as a Fundamental Force of Nature The book begins with an exploration of friction as a fundamental force of nature throughout the history of science....

  11. Analysis of Heat Partitioning During Sliding Contact at High Speed and Pressure

    Science.gov (United States)

    2014-03-27

    the numerical results developed are compared in Chapter 7. Malinowski , Lenard and Davies (35) used the mechanical models of the hot/warm forging...R.F.Harder. “Transient heat partition factor for a sliding railcar wheel,” Wear, 261: 932-936 (2006). 35. Malinowski , Z., J.G.Lenard, and M.E.Davies

  12. Slide 1

    Indian Academy of Sciences (India)

    Table of contents. Slide 1 · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Immunology of VL · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Strategies To Design Drugs · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25 · Slide 26 · Slide 27 · Slide 28.

  13. Slide 1

    Indian Academy of Sciences (India)

    Slide 5 · Slide 6 · Second Question How Did this Shift in ToT Come About? Slide 8 · Second Question How Did this Shift in ToT Come About? Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 17 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25 · Slide 26 · Slide 27 · Slide 30 · India's Globalization.

  14. Detection of the local sliding in the tyre-road contact by measuring vibrations on the inner liner of the tyre

    Science.gov (United States)

    Niskanen, Arto J.; Tuononen, Ari J.

    2017-04-01

    Intelligent tyres can provide vital information from the tyre-road contact, especially for autonomous cars and intelligent infrastructure. In this paper, the acceleration measured on the inner liner of a tyre is used to detect the local sliding in the tyre-road contact. The Hilbert-Huang transform is utilized to extract the relevant vibration components and localize them in the wheel rotation angle domain. The energy of the vibration in the trailing part of the contact is shown to increase in low-friction conditions which can be related to the sliding of the tread part as a result of the shear stresses exceeding the local friction limit. To separate the effect of the surface roughness and the friction, different road surfaces were used in the measurements. In addition, the effects of different driving manoeuvres on the measured accelerations and the propagation of the sliding zone in the contact patch during braking are illustrated.

  15. Detection of the local sliding in the tyre-road contact by measuring vibrations on the inner liner of the tyre

    International Nuclear Information System (INIS)

    Niskanen, Arto J; Tuononen, Ari J

    2017-01-01

    Intelligent tyres can provide vital information from the tyre-road contact, especially for autonomous cars and intelligent infrastructure. In this paper, the acceleration measured on the inner liner of a tyre is used to detect the local sliding in the tyre-road contact. The Hilbert–Huang transform is utilized to extract the relevant vibration components and localize them in the wheel rotation angle domain. The energy of the vibration in the trailing part of the contact is shown to increase in low-friction conditions which can be related to the sliding of the tread part as a result of the shear stresses exceeding the local friction limit. To separate the effect of the surface roughness and the friction, different road surfaces were used in the measurements. In addition, the effects of different driving manoeuvres on the measured accelerations and the propagation of the sliding zone in the contact patch during braking are illustrated. (paper)

  16. Tribology. Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts.

    Science.gov (United States)

    Gosvami, N N; Bares, J A; Mangolini, F; Konicek, A R; Yablon, D G; Carpick, R W

    2015-04-03

    Zinc dialkyldithiophosphates (ZDDPs) form antiwear tribofilms at sliding interfaces and are widely used as additives in automotive lubricants. The mechanisms governing the tribofilm growth are not well understood, which limits the development of replacements that offer better performance and are less likely to degrade automobile catalytic converters over time. Using atomic force microscopy in ZDDP-containing lubricant base stock at elevated temperatures, we monitored the growth and properties of the tribofilms in situ in well-defined single-asperity sliding nanocontacts. Surface-based nucleation, growth, and thickness saturation of patchy tribofilms were observed. The growth rate increased exponentially with either applied compressive stress or temperature, consistent with a thermally activated, stress-assisted reaction rate model. Although some models rely on the presence of iron to catalyze tribofilm growth, the films grew regardless of the presence of iron on either the tip or substrate, highlighting the critical role of stress and thermal activation. Copyright © 2015, American Association for the Advancement of Science.

  17. Separation of contact in a sliding system with frictionally excited thermoelastic instability

    Directory of Open Access Journals (Sweden)

    Voldřich J.

    2007-10-01

    Full Text Available The first phase of the thermoelastic instability, which is characterized by a full contact regime, can be modelled using Fourier decomposition and application of an analytical description. However, in case of further increase of instability, a separation of the contact occurs which is more difficult to cover by mathematical means. The contribution deals with numerical simulations of the separation. The problems are topical in connection with the disk brakes design, should we give an example.

  18. A friction test between steel and a brittle material at high contact pressures and high sliding velocities

    Directory of Open Access Journals (Sweden)

    Picart D.

    2012-08-01

    Full Text Available Our aim is to characterize the interface behaviour between an aggregate material and steel. This work focuses on contact pressures and sliding velocities reaching 100 MPa and 10 m/s. The set-up consists in a cylindrical sample of the aggregate material which slips into a steel tube. The tube is both a confinement vessel and a sliding surface. Thanks to confinement, the material can be tested under high stresses without failure. The interface pressure is generated by an axial compression. The sample is pressed on a spring, so it can be simultaneously compressed and rubbed on the tube. The set-up has been tested in the case of a quasi-static loading and the 100 MPa pressure has been reached. Then the set-up was mounted on a Split Hopkinson Pressure Bar device in order to reach higher velocities. Numerical simulations have been realized to check the feasibility and the relevance of this dynamic test. These results are analysed and compared to the experimental ones.

  19. Slide 1

    Indian Academy of Sciences (India)

    Table of contents. Slide 1 · Matsyagandhya A case of genetic disorder · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Active Site with Molybdopterin Ligation · Disadvantage of a Chemist to Model the Cofactor · Slide 10 · Slide 11 · Slide 12 · Active Site Investigation · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19.

  20. Deformation and friction of MoS2 particles in liquid suspensions used to lubricate sliding contact

    International Nuclear Information System (INIS)

    Sahoo, Rashmi R.; Biswas, Sanjay K.

    2010-01-01

    Tribology of a well known solid lubricant molybdenum disulphide is studied here in water and oil medium, over a large range of contact dimensions. Lateral force microscopy is used to identify the deformation modes; intra-crystalline slip, plastic grooving, fragmentation and fracture, of single particles. The medium and agglomeration were found to dictate the deformation mode. Steel on steel tribology lubricated by suspensions of these particles in liquid media was conducted over a range of contact pressure and sliding velocity. A scrutiny of the frictional data with the aid of Raman spectroscopy to identify the transfer film, suggested that the particle size, as it is at contact, is an important tribological parameter. Ultrasonication of the suspension and dispersion of the particle by surfactants were used to control the apriori particle size fed into the suspension. Correspondence of friction data of the gently sonicated suspension with that of the ultrasonicated suspension with dispersants indicated the importance of liquid ingestion by these particles as it controls their mode of deformation and consequent tribology.

  1. Some fundamental aspects of self-levitating sliding contact bearings and their practical implementations

    OpenAIRE

    Atherton, MA; Mares, C; Stolarski, TA

    2014-01-01

    In this study, fundamental aspects and mechanisms of acoustic levitation together with governing equations are presented first. Then, the acoustic levitation phenomenon is considered as a new way to design air suspension systems capable of self-levitation. A particular emphasis is laid on journal bearings and their specific geometrical configuration. A practical feasibility of using acoustic levitation to separate contacting surfaces is supported and illustrated by results of experimental tes...

  2. Slide 1

    Indian Academy of Sciences (India)

    Slide 25 · Life course epidemiology and chronic diseases · Models · Slide 28 · Slide 29 · Slide 30 · New Delhi Birth Cohort · New Delhi Birth Cohort (NDBC) · Slide 33 · Slide 34 · Slide 35 · Slide 36 · Slide 37 · Slide 38 · Slide 39 · CONCLUSIONS Urban Children and Adolescents · CONCLUSIONS New Delhi Birth Cohort.

  3. Functional parameter screening for predicting durability of rolling sliding contacts with different surface finishes

    Science.gov (United States)

    Dimkovski, Z.; Lööf, P.-J.; Rosén, B.-G.; Nilsson, P. H.

    2018-06-01

    The reliability and lifetime of machine elements such as gears and rolling bearings depend on their wear and fatigue resistance. In order to screen the wear and surface damage, three finishing processes: (i) brushing, (ii) manganese phosphating and (iii) shot peening were applied on three disc pairs and long-term tested on a twin-disc tribometer. In this paper, the elastic contact of the disc surfaces (measured after only few revolutions) was simulated and a number of functional and roughness parameters were correlated. The functional parameters consisted of subsurface stresses at different depths and a new parameter called ‘pressure spikes’ factor’. The new parameter is derived from the pressure distribution and takes into account the proximity and magnitude of the pressure spikes. Strong correlations were found among the pressure spikes’ factor and surface peak/height parameters. The orthogonal shear stresses and Von Mises stresses at the shallowest depths under the surface have shown the highest correlations but no good correlations were found when the statistics of the whole stress fields was analyzed. The use of the new parameter offers a fast way to screen the durability of the contacting surfaces operating at similar conditions.

  4. Friction and Wear of Nanoadditive-Based Biolubricants in Steel-Steel Sliding Contacts: A Comparative Study

    Science.gov (United States)

    Gupta, Rajeev Nayan; Harsha, A. P.

    2018-02-01

    The present work deals with the study of tribo-pair interaction in lubricated sliding contacts. By considering the environmental issues, the sunflower oil was extracted from the sunflower seeds and used as a base lubricant. The two types of the nanoadditives, i.e., CuO and CeO2, varying concentrations from 0.10 to 0.50% w/v were used to formulate the nanolubricants. The compatibility/synergism of the nanoadditives was examined from antifriction and antiwear behavior study with four-ball tester. Also, sunflower oil was modified by the chemical method to improve its fatty acid structure. A comparative tribological and compatibility study was also done in modified oil at similar concentration levels with both types of nanoparticles. The tribological test result exhibits 0.10% w/v concentration of the nanoadditive as optimum due to lowest wear scar and coefficient of friction. Higher concentration of the nanoparticles impaired the base oil performance. Different analytical tools were used to characterize the oil modification and worn surfaces. Moreover, the role of subsurface of the contacting material with the tribological performance has been reported.

  5. Investigation of index finger triggering force using a cadaver experiment: Effects of trigger grip span, contact location, and internal tendon force.

    Science.gov (United States)

    Chang, Joonho; Freivalds, Andris; Sharkey, Neil A; Kong, Yong-Ku; Mike Kim, H; Sung, Kiseok; Kim, Dae-Min; Jung, Kihyo

    2017-11-01

    A cadaver study was conducted to investigate the effects of triggering conditions (trigger grip span, contact location, and internal tendon force) on index finger triggering force and the force efficiency of involved tendons. Eight right human cadaveric hands were employed, and a motion simulator was built to secure and control the specimens. Index finger triggering forces were investigated as a function of different internal tendon forces (flexor digitorum profundus + flexor digitorum superficialis = 40, 70, and 100 N), trigger grip spans (40, 50, and 60 mm), and contact locations between the index finger and a trigger. Triggering forces significantly increased when internal tendon forces increased from 40 to 100 N. Also, trigger grip spans and contact locations had significant effects on triggering forces; maximum triggering forces were found at a 50 mm span and the most proximal contact location. The results revealed that only 10-30% of internal tendon forces were converted to their external triggering forces. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Mapping the spatiotemporal evolution of solute transport in articular cartilage explants reveals how cartilage recovers fluid within the contact area during sliding.

    Science.gov (United States)

    Graham, Brian T; Moore, Axel C; Burris, David L; Price, Christopher

    2018-04-11

    The interstitial fluid within articular cartilage shields the matrix from mechanical stresses, reduces friction and wear, enables biochemical processes, and transports solutes into and out of the avascular extracellular matrix. The balanced competition between fluid exudation and recovery under load is thus critical to the mechanical and biological functions of the tissue. We recently discovered that sliding alone can induce rapid solute transport into buried cartilage contact areas via a phenomenon termed tribological rehydration. In this study, we use in situ confocal microscopy measurements to track the spatiotemporal propagation of a small neutral solute into the buried contact area to clarify the fluid mechanics underlying the tribological rehydration phenomenon. Sliding experiments were interrupted by periodic static loading to enable scanning of the entire contact area. Spatiotemporal patterns of solute transport combined with tribological data suggested pressure driven flow through the extracellular matrix from the contact periphery rather than into the surface via a fluid film. Interestingly, these testing interruptions also revealed dynamic, repeatable and history-independent fluid loss and recovery processes consistent with those observed in vivo. Unlike the migrating contact area, which preserves hydration by moving faster than interstitial fluid can flow, our results demonstrate that the stationary contact area can maintain and actively recover hydration through a dynamic competition between load-induced exudation and sliding-induced recovery. The results demonstrate that sliding contributes to the recovery of fluid and solutes by cartilage within the contact area while clarifying the means by which it occurs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. A Finger Exoskeleton Robot for Finger Movement Rehabilitation

    Directory of Open Access Journals (Sweden)

    Tzu-Heng Hsu

    2017-07-01

    Full Text Available In this study, a finger exoskeleton robot has been designed and presented. The prototype device was designed to be worn on the dorsal side of the hand to assist in the movement and rehabilitation of the fingers. The finger exoskeleton is 3D-printed to be low-cost and has a transmission mechanism consisting of rigid serial links which is actuated by a stepper motor. The actuation of the robotic finger is by a sliding motion and mimics the movement of the human finger. To make it possible for the patient to use the rehabilitation device anywhere and anytime, an Arduino™ control board and a speech recognition board were used to allow voice control. As the robotic finger follows the patients voice commands the actual motion is analyzed by Tracker image analysis software. The finger exoskeleton is designed to flex and extend the fingers, and has a rotation range of motion (ROM of 44.2°.

  8. Sliding vane geometry turbines

    Science.gov (United States)

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  9. The variable contact pressure influence on the tensile force in the process of strip sliding in the flat die in ironing

    Directory of Open Access Journals (Sweden)

    Milan Djordjević

    2016-07-01

    Full Text Available Possibilities to influence the deep drawing process during its duration are limited and generally consist of influences at the flange of the thin sheet, mainly by the contact pressure (the blank holding force. The common characteristics of previous investigations were setting of the fixed values of the blank holding force or the holder's pressure within the ironing tool. The objective of this investigation was the continuous setting of the variable pressure during the sliding process, via the preset functions, in order to analyze the variable pressure influence on the ironing process. This is why an experimental computerized device was designed and constructed for analyzing the influence of the variable contact pressure on the sliding process of the model strip during the flat-die test. The multi-parameter experiment was conducted; various materials of the tested pieces were applied (primarily thin sheet made of Al alloys and low-carbon steels sheet, with and without coating; different versions of the tool's contact elements were used, with various friction regimes and influential parameters (variable contact pressure during the sliding process, etc.. This experimental device practically represents a simulator for realization and studying of the physical model of an important segment of the ironing process in the completely realistic conditions (materials, tools, etc.. The aim was to find the optimal combination of the variable contact pressure and the tribological parameters, so that the punch force, as one of the process output parameters, would have the minimal value, as well as to avoid the undesired effects during the forming (difficult sliding of the flange, appearance of thin sheet's wrinkling, structural destruction, etc.. Understanding the mutual dependence of the holder's variable pressure and other influences should enable improvement of the ironing process control and should contribute to better understanding of the phenomena

  10. High temperature tribological behaviour of carbon based (B{sub 4}C and DLC) coatings in sliding contact with aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Gharam, A. Abou, E-mail: abougha@uwindsor.c [Mechanical Automotive and Materials Engineering Department, University of Windsor, Windsor, ON, N9B3P4 (Canada); Lukitsch, M.J.; Balogh, M.P. [Chemical Sciences and Materials Systems Laboratory, General Motors R and D Center, 30500 Mound Road, Warren, MI 48090-9055 (United States); Alpas, A.T. [Mechanical Automotive and Materials Engineering Department, University of Windsor, Windsor, ON, N9B3P4 (Canada)

    2010-12-30

    Carbon based coatings, particularly diamond-like carbon (DLC) films are known to resist aluminum adhesion and reduce friction at room temperature. This attractive tribological behaviour is useful for applications such as tool coatings used for aluminum forming and machining. However, for those operations that are performed at elevated temperatures (e.g. hot forming) or that generate frictional heat during contact (e.g. dry machining) the suitable coatings are required to maintain their tribological properties at high temperatures. Candidates for these demanding applications include boron carbide (B{sub 4}C) and DLC coatings. An understanding of the mechanisms of friction, wear and adhesion of carbon based coatings against aluminum alloys at high temperatures will help in designing coatings with improved high temperature tribological properties. With this goal in mind, this study focused on B{sub 4}C and a hydrogenated DLC coatings sliding against a 319 grade cast aluminum alloy by performing pin-on-disk experiments at temperatures up to 400 {sup o}C. Experimental results have shown that the 319 Al/B{sub 4}C tribosystem generated coefficient of friction (COF) values ranging between 0.42 and 0.65, in this temperature range. However, increased amounts of aluminum adhesion were detected in the B{sub 4}C wear tracks at elevated temperatures. Focused ion beam (FIB) milled cross sections of the wear tracks revealed that the coating failed due to shearing along the columnar grain boundaries of the coating. The 319 Al/DLC tribosystem maintained a low COF (0.15-0.06) from room temperature up to 200 {sup o}C. This was followed by an abrupt increase to 0.6 at 400 {sup o}C. The deterioration of friction behaviour at T > 200 {sup o}C was attributed to the exhaustion of hydrogen and hydroxyl passivants on the carbon transfer layer formed on the Al pin.

  11. Monte Carlo assessment of the finger shallow dose from direct contact with a microcentrifuge tube containing common biotechnology isotopes in solution.

    Science.gov (United States)

    Cutright, Dan; Medich, David; Ring, Joseph

    2012-04-01

    Eppendorf tubes often are used in biomedical research labs and contain radioactive tracers. Although the associated direct contact finger doses are typically small, it is suggested (and in line with the principle of ALARA) to handle these tubes from the cap of the tube. When containing radioactive material, handling a tube near the bottom conical section would unnecessarily increase the skin dose to the fingers. This investigation modeled a 2.0-mL Eppendorf tube containing various individual beta emitting isotopes commonly used in a biomedical research environment (i.e., (14)C, (3)H, (131)I, (32)P, and (35)S) to determine the skin dose when directly handling the tube at the cap end and when handling it at the bottom conical section. The primary goal of this paper is to assess how significantly this dose is altered by handling geometry. The skin dose to a single finger was calculated with Monte Carlo simulations using MCNP5 and determined at a depth of 0.007 cm(2) in water averaged over 10 cm as described in 10CFR20. Results show that the dose rate may vary by as much as a factor of 700 depending on handling geometry.

  12. Slide 1

    Indian Academy of Sciences (India)

    Potency of Stem Cells · Slide 3 · Slide 4 · Slide 5 · World Wide Clinical trials using MSCs · Slide 7 · Bone Marrow derived Human MSCs (hMSC) in culture · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Fetal MSCs · Morphology of murine fetal heart derived stem cells (fHSCs) · Growth Kinetics of fHSCs · Phenotype of ...

  13. Trigger finger

    Science.gov (United States)

    ... digit; Trigger finger release; Locked finger; Digital flexor tenosynovitis ... cut or hand Yellow or green drainage from the cut Hand pain or discomfort Fever If your trigger finger returns, call your surgeon. You may need another surgery.

  14. Effect of fluorocarbon self-assembled monolayer films on sidewall adhesion and friction of surface micromachines with impacting and sliding contact interfaces

    International Nuclear Information System (INIS)

    Xiang, H.; Komvopoulos, K.

    2013-01-01

    A self-assembled monolayer film consisting of fluoro-octyltrichlorosilane (FOTS) was vapor-phase deposited on Si(100) substrates and polycrystalline silicon (polysilicon) surface micromachines. The hydrophobic behavior and structural composition of the FOTS film deposited on Si(100) were investigated by goniometry and X-ray photoelectron spectroscopy, respectively. The effects of contact pressure, relative humidity, temperature, and impact/sliding cycles on the adhesive and friction behavior of uncoated and FOTS-coated polysilicon micromachines (referred to as the Si and FOTS/Si micromachines, respectively) were investigated under controlled loading and environmental conditions. FOTS/Si micromachines demonstrated much lower and stable adhesion than Si micromachines due to the highly hydrophobic and conformal FOTS film. Contrary to Si micromachines, sidewall adhesion of FOTS/Si micromachines demonstrated a weak dependence on relative humidity, temperature, and impact cycles. In addition, FOTS/Si micromachines showed low and stable adhesion and low static friction for significantly more sliding cycles than Si micromachines. The adhesive and static friction characteristics of Si and FOTS/Si micromachines are interpreted in the context of physicochemical surface changes, resulting in the increase of the real area of contact and a hydrophobic-to-hydrophilic transition of the surface chemical characteristics caused by nanoscale surface smoothening and the removal of the organic residue (Si micromachines) or the FOTS film (FOTS/Si micromachines) during repetitive impact and oscillatory sliding of the sidewall surfaces.

  15. Finger pad friction and its role in grip and touch

    Science.gov (United States)

    Adams, Michael J.; Johnson, Simon A.; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis

    2013-01-01

    Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function. PMID:23256185

  16. Finger pad friction and its role in grip and touch.

    Science.gov (United States)

    Adams, Michael J; Johnson, Simon A; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis

    2013-03-06

    Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick-slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function.

  17. The influence of physical properties of materials used for slide rings on the process of heat transfer in the non-contacting face seals

    Directory of Open Access Journals (Sweden)

    Blasiak Slawomir

    2017-01-01

    Full Text Available The paper presents the results of analytical solution of the model of heat transfer for non-contacting face seals. Comparative analyses were performed for various physical properties of materials used for slide rings. A mathematical model includes a series of differential equations of partial derivatives with generally used boundary conditions, i.e. the Reynold’s equation, energy equation and heat transfer equations, which describe the heat transfer in sealing rings with surrounding medium. Heat transfer equation is written in the Cartesian coordinate system and solved using the Green’s functions method. Theoretical studies made it possible to draw a number of practical conclusions on the phenomena of heat transfer in the node seal. The presented model will allow more accurate identification of the heat transfer mechanism in the node seal. The results will help to select appropriate materials for sealing rings, depending on operating conditions of non-contacting face seals.

  18. MEMS-based contact stress field measurements at a rough elastomeric layer: local test of Amontons’ friction law in static and steady sliding regimes

    Directory of Open Access Journals (Sweden)

    Debrégeas G.

    2010-06-01

    Full Text Available We present the results of recent friction experiments in which a MEMS-based sensing device is used to measure both the normal and tangential stress fields at the base of a rough elastomer film in frictional contact with smooth, rigid, glass indentors. We consider successively multicontacts under (i static normal loading by a spherical indentor and (ii frictional steady sliding conditions against a cylindrical indentor, for an increasing normal load. In both cases, the measured fields are compared to elastic calculations assuming (i a smooth interface and (ii Amontons’ friction law. In the static case, significant deviations are observed which decrease with increasing load and which vanish when a lubricant is used. In the steady sliding case, Amontons’ law reproduces rather satisfactorily the experiments provided that the normal/tangential coupling at the contact interface is taken into account. We discuss the origin of the difference between the Amontons fields and the measured ones, in particular the effect of the finite normal and tangential compliances of the multicontact interface.

  19. Effects of Material Combinations on Friction and Wear of PEEK/Steel Pairs under Oil-Lubricated Sliding Contacts

    Science.gov (United States)

    Akagaki, T.; Nakamura, T.; Hashimoto, Y.; Kawabata, M.

    2017-05-01

    The effects of material combinations on the friction and wear of PEEK/steel pairs are studied using blocks on a ring wear tester under oil-lubricated conditions. The rings are made of forged steel (SF540A) and a PEEK composite filled with 30 wt% carbon fibre. The surface roughness is 0.15 and 0.32 μm Ra, respectively. The blocks are also made of the same materials as the rings: the forged steel and the PEEK composite. Finished with an emery paper of #600, the surface roughness is 0.06 and 0.23 μm Ra, respectively. Sliding tests for 4 combinations of two materials are conducted. The load is increased up to 1177 N at 1 N s-1. The sliding velocity is varied in the range of 10 to 19 m s-1. In some cases, the ring temperature is measured with a thermocouple with a diameter of 0.5 mm, located 1 mm below the frictional surface. Results indicate that the forged steel’s ring and the PEEK composite’s block is the best combination among 4 combinations, because seizure does not occur under the increasing load up to 1177 N at the sliding velocity of 10-19 m s-1. In contrast, seizure occurs at 15 and 19 m s-1 in the other three combinations. However, the PEEK composite’s ring shows a lower friction coefficient as compared to the forged steel’s ring, when seizure does not occur. Wear scars are observed with a scanning electron microscope (SEM). The seizure mechanisms are then discussed.

  20. The Performance of PS400 Subjected to Sliding Contact at Temperatures from 260 to 927 deg C

    Science.gov (United States)

    2016-09-14

    bilities. Such candidate applications include process control valve stems, inlet guide vane bushings , butterfly valve stems, and waste gate valves for...cobalt-based superalloy bushings loaded against reciprocating PS400-coated shaft specimens in a flat-on-cylinder configuration at Hertz contact...contact at temperatures from 260 to 927C. The tests were performed on stationary, uncoated cobalt-based superalloy bushings loaded against

  1. Figure/Ground Segmentation via a Haptic Glance: Attributing Initial Finger Contacts to Objects or Their Supporting Surfaces.

    Science.gov (United States)

    Pawluk, D; Kitada, R; Abramowicz, A; Hamilton, C; Lederman, S J

    2011-01-01

    The current study addresses the well-known "figure/ground" problem in human perception, a fundamental topic that has received surprisingly little attention from touch scientists to date. Our approach is grounded in, and directly guided by, current knowledge concerning the nature of haptic processing. Given inherent figure/ground ambiguity in natural scenes and limited sensory inputs from first contact (a "haptic glance"), we consider first whether people are even capable of differentiating figure from ground (Experiments 1 and 2). Participants were required to estimate the strength of their subjective impression that they were feeling an object (i.e., figure) as opposed to just the supporting structure (i.e., ground). Second, we propose a tripartite factor classification scheme to further assess the influence of kinetic, geometric (Experiments 1 and 2), and material (Experiment 2) factors on haptic figure/ground segmentation, complemented by more open-ended subjective responses obtained at the end of the experiment. Collectively, the results indicate that under certain conditions it is possible to segment figure from ground via a single haptic glance with a reasonable degree of certainty, and that all three factor classes influence the estimated likelihood that brief, spatially distributed fingertip contacts represent contact with an object and/or its background supporting structure.

  2. Steady sliding frictional contact problem for a 2d elastic half-space with a discontinuous friction coefficient and related stress singularities

    Science.gov (United States)

    Ballard, Patrick

    2016-12-01

    The steady sliding frictional contact problem between a moving rigid indentor of arbitrary shape and an isotropic homogeneous elastic half-space in plane strain is extensively analysed. The case where the friction coefficient is a step function (with respect to the space variable), that is, where there are jumps in the friction coefficient, is considered. The problem is put under the form of a variational inequality which is proved to always have a solution which, in addition, is unique in some cases. The solutions exhibit different kinds of universal singularities that are explicitly given. In particular, it is shown that the nature of the universal stress singularity at a jump of the friction coefficient is different depending on the sign of the jump.

  3. Transparent and Flexible Self-Charging Power Film and Its Application in a Sliding Unlock System in Touchpad Technology.

    Science.gov (United States)

    Luo, Jianjun; Tang, Wei; Fan, Feng Ru; Liu, Chaofeng; Pang, Yaokun; Cao, Guozhong; Wang, Zhong Lin

    2016-08-23

    Portable and wearable personal electronics and smart security systems are accelerating the development of transparent, flexible, and thin-film electronic devices. Here, we report a transparent and flexible self-charging power film (SCPF) that functions either as a power generator integrated with an energy storage unit or as a self-powered information input matrix. The SCPF possesses the capability of harvesting mechanical energy from finger motions, based on the coupling between the contact electrification and electrostatic induction effects, and meanwhile storing the generated energy. Under the fast finger sliding, the film can be charged from 0 to 2.5 V within 2094 s and discharge at 1 μA for approximately 1630 s. Furthermore, the film is able to identify personal characteristics during a sliding motion by recording the electric signals related to the person's individual bioelectricity, applied pressing force, sliding speed, and so on, which shows its potential applications in security systems in touchpad technology.

  4. TRANSFORMATION AND SCATTERING OF SURFACE WAVES ON THE ACOUSTIC LOAD TO ULTRASONIC EVALUATION AND MEASUREMENTS. Part 1. The boundary of acoustic contact is sliding

    Directory of Open Access Journals (Sweden)

    A. R. Baev

    2018-01-01

    Full Text Available for the enhancement and improvement of ultrasonic methods evaluation and measurements. The purpose of this work is to determine the influence of the geometric parameters of the acoustic load body and its position on the coefficients of reflection and propagation of the Stoneley and Rayleigh waves and to identify the possibility of using the results of the study for practical applications.Based on the analysis of the acoustic path and the experimental data, the relationship between the measured amplitude parameters and the coefficients of the propagation and reflection of surface waves, as well as the reflectivity of the contact region of the load body in the form of a prism through the sliding boundary, which reaches up to ≈ 32–34 дБ, is established. For the first time, the dependence of these coefficients on the inclination angle of one of the prism lateral faces in the range of 0 ± 45°, dimensionless thickness of the contact layer (0–0,05 and its orientation relative to the acoustic axis.It is established that these coefficients are mainly maximal when the prism is rectangular. The coefficient of reflectivity in the hard contact of bodies is more than an order of magnitude less, and the coefficients of wave propagation – comparable in magnitude. The prospects of using the results of the study to evaluate the quality of adhesion of materials during welding, soldering, gluing, detection of defects in hardto-reach places, as well as to determine the physical and mechanical properties of metals by the proposed method of creating a reference signal are shown.

  5. Slide 1

    Indian Academy of Sciences (India)

    Projected Rainfall (Weighted Mean CDF; A1B scenario) · Slide 18 · Imprecise Probability · Bounds for Probability of Drought · Slide 21 · Possibility Distribution of GCMs and Scenarios · Mahanadi River Basin - Streamflow · Projections for future monsoon inflows to Hirakud Reservoir · Slide 25 · Rule curve for adaptive policies.

  6. Use of Textured Surfaces to Mitigate Sliding Friction and Wear of Lubricated and Non-Lubricated Contacts

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2012-03-01

    If properly employed, the placement of three-dimensional feature patterns, also referred to as textures, on relatively-moving, load-bearing surfaces can be beneficial to their friction and wear characteristics. For example, geometric patterns can function as lubricant supply channels or depressions in which to trap debris. They can also alter lubricant flow in a manner that produces thicker load-bearing films locally. Considering the area occupied by solid areas and spaces, textures also change the load distribution on surfaces. At least ten different attributes of textures can be specified, and their combinations offer wide latitude in surface engineering. By employing directional machining and grinding procedures, texturing has been used on bearings and seals for well over a half century, and the size scales of texturing vary widely. This report summarizes past work on the texturing of load-bearing surfaces, including past research on laser surface dimpling of ceramics done at ORNL. Textured surfaces generally show most pronounced effects when they are used in conformal or nearly conformal contacts, like that in face seals. Combining textures with other forms of surface modification and lubrication methods can offer additional benefits in surface engineering for tribology. As the literature and past work at ORNL shows, texturing does not always provide benefits. Rather, the selected pattern and arrangement of features must be matched to characteristics of the proposed application, bearing materials, and lubricants.

  7. Trigger Finger

    Science.gov (United States)

    ... in a bent position. People whose work or hobbies require repetitive gripping actions are at higher risk ... developing trigger finger include: Repeated gripping. Occupations and hobbies that involve repetitive hand use and prolonged gripping ...

  8. Slide 1

    Indian Academy of Sciences (India)

    Game Theory · Strategic Form Games (Normal Form Games) · Example : Prisoner's Dilemma · Dominant Strategy Equilibrium · Nash Equilibrium · Nash's Theorem · Slide 17 · Slide 18 · Example 1: Mechanism Design Fair Division of a Cake · Example 2: Mechanism Design Truth Elicitation through an Indirect Mechanism.

  9. Robotic hand and fingers

    Science.gov (United States)

    Salisbury, Curt Michael; Dullea, Kevin J.

    2017-06-06

    Technologies pertaining to a robotic hand are described herein. The robotic hand includes one or more fingers releasably attached to a robotic hand frame. The fingers can abduct and adduct as well as flex and tense. The fingers are releasably attached to the frame by magnets that allow for the fingers to detach from the frame when excess force is applied to the fingers.

  10. Finger pain

    Science.gov (United States)

    ... become injured from: Playing contact sports such as football, baseball, or soccer Doing recreational activities such as ... Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, ...

  11. Slide layout and integrated design (SLIDE) program

    International Nuclear Information System (INIS)

    Roberts, S.G.

    1975-01-01

    SLIDE is a FORTRAN IV program for producing 35 mm color slides on the Control Data CYBER-74. SLIDE interfaces with the graphics package, DISSPLA, on the CYBER-74. It was designed so that persons with no previous computer experience can easily and quickly generate their own textual 35 mm color slides for verbal presentations. SLIDE's features include seven different colors, five text sizes, ten tab positions, and two page sizes. As many slides as desired may be produced during any one run of the program. Each slide is designed to represent an 8 1 / 2 in. x 11 in. or an 11 in. x 8 1 / 2 in. page. The input data cards required to run the SLIDE program and the program output are described. Appendixes contain a sample program run showing input, output, and the resulting slides produced and a FORTRAN listing of the SLIDE program. (U.S.)

  12. Fingers that change color

    Science.gov (United States)

    ... gov/ency/article/003249.htm Fingers that change color To use the sharing features on this page, please enable JavaScript. Fingers or toes may change color when they are exposed to cold temperatures or ...

  13. Correlation between the concentration of serum polychlorinated biphenyls (PCBs) in pregnant cynomolgus monkeys and their offspring's behavioral scores in eye-contact test and finger maze learning test

    Energy Technology Data Exchange (ETDEWEB)

    Negishi, T. [Aoyama Gakuin Univ., Kanagawa (Japan); Takasuga, T. [Shimadzu Techno-Research Inc., Kyoto (Japan); Kawasaki, K. [Hoshi Univ., Tokyo (Japan); Kuroda, Y. [CREST Japan Science and Technology Corp., Saitama (Japan); Yoshikawa, Y. [The Univ. of Tokyo (Japan)

    2004-09-15

    A recent review suggested that pre- or perinatal exposure of developing fetuses to dioxins, the widespread environmental contaminants, such as polychrorinated biphenlys (PCBs), induce the irreversible abnormalities in the functions of central nervous system (CNS) in human. These chemicals can be transferred to each fetus and naonate transplacentally and lactationally in rhesus monkey. Several studies also reported the adverse effect of PCB on CNS development in rodents and monkeys as well as on behavior in rodents and monkeys. In the present study, we show a preliminary data about the correlation between the serum concentrations of PCBs in pregnant cynomolgus monkeys (Macaca fascicularis) and the scores of two behavioral tests, eye-contact test and four-step finger maze test, which evaluate consciousness against human observer and learning ability, respectively, in their offspring. This experimental surveillance system using non-human primates would be useful to predict the risk of PCBs exposure in human fetuses because of the similarities of cynomolgus monkey to human with regard to reproduction, developmental parameter, and others.

  14. Moving Fingers under a Stick: A Laboratory Activity

    Science.gov (United States)

    Massalha, Taha; Lanir, Yuval; Gluck, Paul

    2011-01-01

    We consider a demonstration in which pupils alternately slide and stop their fingers under a long horizontal rod which they support. The changeover is described in terms of the relevant kinetic and static friction. We present a model calculation, performed on a spreadsheet, which clarifies the process and describes graphically the stepwise…

  15. Preparation of a durable superhydrophobic membrane by electrospinning poly (vinylidene fluoride) (PVDF) mixed with epoxy-siloxane modified SiO2 nanoparticles: a possible route to superhydrophobic surfaces with low water sliding angle and high water contact angle.

    Science.gov (United States)

    Wang, Shuai; Li, Yapeng; Fei, Xiaoliang; Sun, Mingda; Zhang, Chaoqun; Li, Yaoxian; Yang, Qingbiao; Hong, Xia

    2011-07-15

    A durable superhydrophobic surface with low water sliding angle (SA) and high water contact angle (CA) was obtained by electrospinning poly (vinylidene fluoride) (PVDF) which was mixed with epoxy-siloxane modified SiO(2) nanoparticles. To increase the roughness, modified SiO(2) nanoparticles were introduced into PVDF precursor solution. Then in the electrospinning process, nano-sized SiO(2) particles irregularly inlayed (it could also be regard as self-assembly) in the surface of the micro-sized PVDF mini-islands so as to form a dual-scale structure. This structure was responsible for the superhydrophobicity and self-cleaning property. In addition, epoxy-siloxane copolymer was used to modify the surface of SiO(2) nanoparticles so that the SiO(2) nanoparticles could stick to the surface of the micro-sized PVDF mini-islands. Through the underwater immersion test, the SiO(2) nanoparticles cannot be separated from PVDF easily so as to achieve the effect of durability. We chiefly explore the surface wettability and the relationship between the mass ratio of modified SiO(2) nanoparticles/PVDF and the CA, SA of electrospun mat. As the content of modified SiO(2) nanoparticles increased, the value of CA increased, ranging from 145.6° to 161.2°, and the water SA decreased to 2.17°, apparently indicating that the membrane we fabricated has a perfect effect of superhydrophobicity. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Multiple Fingers - One Gestalt.

    Science.gov (United States)

    Lezkan, Alexandra; Manuel, Steven G; Colgate, J Edward; Klatzky, Roberta L; Peshkin, Michael A; Drewing, Knut

    2016-01-01

    The Gestalt theory of perception offered principles by which distributed visual sensations are combined into a structured experience ("Gestalt"). We demonstrate conditions whereby haptic sensations at two fingertips are integrated in the perception of a single object. When virtual bumps were presented simultaneously to the right hand's thumb and index finger during lateral arm movements, participants reported perceiving a single bump. A discrimination task measured the bump's perceived location and perceptual reliability (assessed by differential thresholds) for four finger configurations, which varied in their adherence to the Gestalt principles of proximity (small versus large finger separation) and synchrony (virtual spring to link movements of the two fingers versus no spring). According to models of integration, reliability should increase with the degree to which multi-finger cues integrate into a unified percept. Differential thresholds were smaller in the virtual-spring condition (synchrony) than when fingers were unlinked. Additionally, in the condition with reduced synchrony, greater proximity led to lower differential thresholds. Thus, with greater adherence to Gestalt principles, thresholds approached values predicted for optimal integration. We conclude that the Gestalt principles of synchrony and proximity apply to haptic perception of surface properties and that these principles can interact to promote multi-finger integration.

  17. Effective lecture slides

    International Nuclear Information System (INIS)

    Lim, Jae Hoon

    1986-01-01

    Lawyers, with their constant opportunity for practice, show a talent for public oratory that few doctors can equal. However, the physician, despite his more modest and hesitant delivery, has one great advantage over the most experienced lawyer. He is allowed to use slides. Slides of good quality conceal defects in oratory and they make for a confident speaker and a contented audience. By contrast, smudged, complicated or ill prepared slides may draw attention to minor defects in delivery and make the audience inattentive.

  18. Crystalline misfit-angle implications for solid sliding

    International Nuclear Information System (INIS)

    Manini, Nicola; Braun, O.M.

    2011-01-01

    For the contact of two finite portions of interacting rigid crystalline surfaces, we compute the pinning energy barrier dependency on the misfit angle and contact area. This simple model allows us to investigate a broad contact-size and angular range, thus obtaining the statistical properties of the energy barriers opposing sliding for a single asperity. These data are used to generate the distribution of static frictional thresholds for the contact of polycrystals, as in dry or even lubricated friction. This distribution is used as the input of a master equation to predict the sliding properties of macroscopic contacts. -- Highlights: → The pinning energy barrier depends on the misfit angle and contact area. → We compute this dependence for a idealized rigid model. → We obtain a distribution of static frictional thresholds. → It is used as input of a master-equation model for macroscopic surfaces in contact. → Overall we predict a transition from stick-slip to smooth sliding.

  19. Left hand finger force in violin playing: tempo, loudness, and finger differences.

    Science.gov (United States)

    Kinoshita, Hiroshi; Obata, Satoshi

    2009-07-01

    A three-dimensional force transducer was installed in the neck of a violin under the A string at the D5 position in order to study the force with which the violinist clamps the string against the fingerboard under normal playing conditions. Violinists performed repetitive sequences of open A- and fingered D-tones using the ring finger at tempi of 1, 2, 4, 8, and 16 notes/s at mezzo-forte. At selected tempi, the effects of dynamic level and the use of different fingers were investigated as well. The force profiles were clearly dependent on tempo and dynamic level. At slow tempi, the force profiles were characterized by an initial pulse followed by a level force to the end of the finger contact period. At tempi higher than 2 Hz, only pulsed profiles were observed. The peak force exceeded 4.5 N at 1 and 2 Hz and decreased to 1.7 N at 16 Hz. All force and impulse values were lower at softer dynamic levels, and when using the ring or little finger compared to the index finger.

  20. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  1. A Simple Measurement of the Sliding Friction Coefficient

    Science.gov (United States)

    Gratton, Luigi M.; Defrancesco, Silvia

    2006-01-01

    We present a simple computer-aided experiment for investigating Coulomb's law of sliding friction in a classroom. It provides a way of testing the possible dependence of the friction coefficient on various parameters, such as types of materials, normal force, apparent area of contact and sliding velocity.

  2. Multi-fingered robotic hand

    Science.gov (United States)

    Ruoff, Carl F. (Inventor); Salisbury, Kenneth, Jr. (Inventor)

    1990-01-01

    A robotic hand is presented having a plurality of fingers, each having a plurality of joints pivotally connected one to the other. Actuators are connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is covering of the tip of each finger with a resilient and pliable friction enhancing surface.

  3. Mixing methods, tasting fingers

    DEFF Research Database (Denmark)

    Mann, Anna; Mol, Annemarie; Satalkar, Priya

    2011-01-01

    This article reports on an ethnographic experiment. Four finger eating experts and three novices sat down for a hot meal and ate with their hands. Drawing on the technique of playing with the familiar and the strange, our aim was not to explain our responses, but to articulate them. As we seek...... words to do so, we are compelled to stretch the verb "to taste." Tasting, or so our ethnographic experiment suggests, need not be understood as an activity confined to the tongue. Instead, if given a chance, it may viscously spread out to the fingers and come to include appreciative reactions otherwise...

  4. Mixing methods, tasting fingers

    DEFF Research Database (Denmark)

    Mann, Anna; Mol, Annemarie; Satalkar, Priya

    2011-01-01

    This article reports on an ethnographic experiment. Four finger eating experts and three novices sat down for a hot meal and ate with their hands. Drawing on the technique of playing with the familiar and the strange, our aim was not to explain our responses, but to articulate them. As we seek wo...

  5. Trigger Finger (Stenosing Tenosynovitis)

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Trigger Finger Email to a friend * required fields ...

  6. FRICTION TORQUE IN THE SLIDE BEARINGS

    Directory of Open Access Journals (Sweden)

    BONDARENKO L. N.

    2016-09-01

    Full Text Available Summary. Problem statement. Until now slide bearings are used widely in engineering. But the calculation is made on obsolete method that is based on undetermined parameters such as wear of the bearing shell. It is accepted in the literature that if the shaft and liner material are homogeneous, the workpiece surface are cylindrical as they wear and contact between them occurs at all points contact arc. Research objective. The purpose of this study is determine a friction torque in the slide bearings of power-basis parameters. Conclusions. Since the friction is primarily responsible for wear of cinematic pairs “pin – liner” and “pivot – liner” slide bearings. It is shown that the friction torquesof angles wrap, that are obtained by the formulas and given in literature, are not only qualitatively but also quantitatively, namely, the calculation by literature to the formulas the friction torques are proportional to the angle wrap and the calculation by improved formulas the friction torques are inversely proportional to the angle wrap due to the reduction the normal pressure. Underreporting friction torque at large angle wrap is between 40 and 15 %. The difference in the magnitude of friction torque in the run-in and run-out cinematic pairs with real method of machining is 2...3 %, which it is possible to declare of reducing the finish of contacting surface of slide bearings.

  7. Mechanics of slide dams

    International Nuclear Information System (INIS)

    Young, G.A.

    1970-01-01

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  8. Mechanics of slide dams

    Energy Technology Data Exchange (ETDEWEB)

    Young, G A [Engineering, Agbabian-Jacobsen Associates, Los Angeles (United States)

    1970-05-15

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  9. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  10. Influence of normal loads and sliding velocities on friction properties of engineering plastics sliding against rough counterfaces

    International Nuclear Information System (INIS)

    Nuruzzaman, D M; Chowdhury, M A; Rahaman, M L; Oumer, A N

    2016-01-01

    Friction properties of plastic materials are very important under dry sliding contact conditions for bearing applications. In the present research, friction properties of engineering plastics such as polytetrafluoroethylene (PTFE) and nylon are investigated under dry sliding contact conditions. In the experiments, PTFE and nylon slide against different rough counterfaces such as mild steel and stainless steel 316 (SS 316). Frictional tests are carried out at low loads 5, 7.5 and 10 N, low sliding velocities 0.5, 0.75 and 1 m/s and relative humidity 70%. The obtained results reveal that friction coefficient of PTFE increases with the increase in normal loads and sliding velocities within the observed range. On the other hand, frictional values of nylon decrease with the increase in normal loads and sliding velocities. It is observed that in general, these polymers show higher frictional values when sliding against SS 316 rather than mild steel. During running-in process, friction coefficient of PTFE and nylon steadily increases with the increase in rubbing time and after certain duration of rubbing, it remains at steady level. At identical operating conditions, the frictional values are significantly different depending on normal load, sliding velocity and material pair. It is also observed that in general, the influence of normal load on the friction properties of PTFE and nylon is greater than that of sliding velocity. (paper)

  11. Selected Landscape Plants. Slide Script.

    Science.gov (United States)

    McCann, Kevin

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important woody ornamental landscape plants. Included in the script are narrations for use with a total of 253 slides illustrating 92 different plants. Several slides are used to illustrate each plant: besides a view of…

  12. Universal Aging Mechanism for Static and Sliding Friction of Metallic Nanoparticles.

    Science.gov (United States)

    Feldmann, Michael; Dietzel, Dirk; Tekiel, Antoni; Topple, Jessica; Grütter, Peter; Schirmeisen, André

    2016-07-08

    The term "contact aging" refers to the temporal evolution of the interface between a slider and a substrate usually resulting in increasing friction with time. Current phenomenological models for multiasperity contacts anticipate that such aging is not only the driving force behind the transition from static to sliding friction, but at the same time influences the general dynamics of the sliding friction process. To correlate static and sliding friction on the nanoscale, we show experimental evidence of stick-slip friction for nanoparticles sliding on graphite over a wide dynamic range. We can assign defined periods of aging to the stick phases of the particles, which agree with simulations explicitly including contact aging. Additional slide-hold-slide experiments for the same system allow linking the sliding friction results to static friction measurements, where both friction mechanisms can be universally described by a common aging formalism.

  13. Bifurcation of elastic solids with sliding interfaces

    Science.gov (United States)

    Bigoni, D.; Bordignon, N.; Piccolroaz, A.; Stupkiewicz, S.

    2018-01-01

    Lubricated sliding contact between soft solids is an interesting topic in biomechanics and for the design of small-scale engineering devices. As a model of this mechanical set-up, two elastic nonlinear solids are considered jointed through a frictionless and bilateral surface, so that continuity of the normal component of the Cauchy traction holds across the surface, but the tangential component is null. Moreover, the displacement can develop only in a way that the bodies in contact do neither detach, nor overlap. Surprisingly, this finite strain problem has not been correctly formulated until now, so this formulation is the objective of the present paper. The incremental equations are shown to be non-trivial and different from previously (and erroneously) employed conditions. In particular, an exclusion condition for bifurcation is derived to show that previous formulations based on frictionless contact or `spring-type' interfacial conditions are not able to predict bifurcations in tension, while experiments-one of which, ad hoc designed, is reported-show that these bifurcations are a reality and become possible when the correct sliding interface model is used. The presented results introduce a methodology for the determination of bifurcations and instabilities occurring during lubricated sliding between soft bodies in contact.

  14. Investigation of material transfer in sliding friction-topography or surface chemistry?

    OpenAIRE

    Westlund, V.; Heinrichs, J.; Olsson, M.; Jacobson, S.

    2016-01-01

    To differentiate between the roles of surface topography and chemical composition on influencing friction and transfer in sliding contact, a series of tests were performed in situ in an SEM. The initial sliding during metal forming was investigated, using an aluminum tip representing the work material, put into sliding contact with a polished flat tool material. Both DLC-coated and uncoated tool steel was used. By varying the final polishing step of the tool material, different surface topogr...

  15. Robotic Finger Assembly

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert J., Jr. (Inventor); Hargrave, Brian (Inventor); Askew, Scott R. (Inventor); Valvo, Michael C. (Inventor)

    2014-01-01

    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

  16. Hidradenocarcinoma of the finger.

    Science.gov (United States)

    Nazerali, Rahim S; Tan, Cynthia; Fung, Maxwell A; Chen, Steven L; Wong, Michael S

    2013-04-01

    Hidradenocarcinoma is a rare adnexal neoplasm representing the malignant counterpart of hidradenoma derived from eccrine sweat glands. Misdiagnosis of this disease is common due to the wide variety of histological patterns and rarity of this malignancy. We report an 87-year-old man presenting with a rare case of biopsy-proven hidradenocarcinoma of the finger. There is no standard care of treatment of hidradenocarcinoma, especially of those tumors in rare locations such as the fingers, given its rarity, variable tumor behavior and histology. Although limited treatment strategies exist, detailed data including TNM, location, histologic type and grade, and patient age should be gathered for optimal treatment strategy. The literature supports a 3-fold approach to these malignancies involving margin-free resection, sentinel lymph node biopsy to evaluate possible metastasis, and long-term follow-up given high risk of recurrence. Our treatment strategy involved a 4-fold, multidisciplinary approach involving reconstruction to optimize tumor-free remission and hand function.

  17. Simulations of atomic-scale sliding friction

    DEFF Research Database (Denmark)

    Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel; Stoltze, Per

    1996-01-01

    Simulation studies of atomic-scale sliding friction have been performed for a number of tip-surface and surface-surface contacts consisting of copper atoms. Both geometrically very simple tip-surface structures and more realistic interface necks formed by simulated annealing have been studied....... Kinetic friction is observed to be caused by atomic-scale Stick and slip which occurs by nucleation and subsequent motion of dislocations preferably between close-packed {111} planes. Stick and slip seems ro occur in different situations. For single crystalline contacts without grain boundaries...... pinning of atoms near the boundary of the interface and is therefore more easily observed for smaller contacts. Depending on crystal orientation and load, frictional wear can also be seen in the simulations. In particular, for the annealed interface-necks which model contacts created by scanning tunneling...

  18. Finger Injuries in Football and Rugby.

    Science.gov (United States)

    Elzinga, Kate E; Chung, Kevin C

    2017-02-01

    Football and rugby athletes are at increased risk of finger injuries given the full-contact nature of these sports. Some players may return to play early with protective taping, splinting, and casting. Others require a longer rehabilitation period and prolonged time away from the field. The treating hand surgeon must weigh the benefits of early return to play for the current season and future playing career against the risks of reinjury and long-term morbidity, including post-traumatic arthritis and decreased range of motion and strength. Each player must be comprehensively assessed and managed with an individualized treatment plan. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Differences in finger localisation performance of patients with finger agnosia.

    Science.gov (United States)

    Anema, Helen A; Kessels, Roy P C; de Haan, Edward H F; Kappelle, L Jaap; Leijten, Frans S; van Zandvoort, Martine J E; Dijkerman, H Chris

    2008-09-17

    Several neuropsychological studies have suggested parallel processing of somatosensory input when localising a tactile stimulus on one's own by pointing towards it (body schema) and when localising this touched location by pointing to it on a map of a hand (body image). Usually these reports describe patients with impaired detection, but intact sensorimotor localisation. This study examined three patients with a lesion of the angular gyrus with intact somatosensory processing, but with selectively disturbed finger identification (finger agnosia). These patients performed normally when pointing towards the touched finger on their own hand but failed to indicate this finger on a drawing of a hand or to name it. Similar defects in the perception of other body parts were not observed. The findings provide converging evidence for the dissociation between body image and body schema and, more importantly, reveal for the first time that this distinction is also present in higher-order cognitive processes selectively for the fingers.

  20. Planning Robotic Manipulation Strategies for Sliding Objects

    Science.gov (United States)

    Peshkin, Michael A.

    Automated planning of grasping or manipulation requires an understanding of both the physics and the geometry of manipulation, and a representation of that knowledge which facilitates the search for successful strategies. We consider manipulation on a level conveyor belt or tabletop, on which a part may slide when touched by a robot. Manipulation plans for a given part must succeed in the face of two types of uncertainty: that of the details of surfaces in contact, and that of the initial configuration of the part. In general the points of contact between the part and the surface it slides on will be unknown, so the motion of the part in response to a push cannot be predicted exactly. Using a simple variational principle (which is derived), we find the set of possible motions of a part for a given push, for all collections of points of contact. The answer emerges as a locus of centers of rotation (CORs). Manipulation plans made using this locus will succeed despite unknown details of contact. Results of experimental tests of the COR loci are presented. Uncertainty in the initial configuration of a part is usually also present. To plan in the presence of uncertainty, configuration maps are defined, which map all configurations of a part before an elementary operation to all possible outcomes, thus encapsulating the physics and geometry of the operation. The configuration map for an operation sequence is a product of configuration maps of elementary operations. Using COR loci we compute configuration maps for elementary sliding operations. Appropriate search techniques are applied to find operation sequences which succeed in the presence of uncertainty in the initial configuration and unknown details of contact. Such operation sequences may be used as parts feeder designs or as manipulation or grasping strategies for robots. As an example we demonstrate the automated design of a class of passive parts feeders consisting of multiple sequential fences across a conveyor

  1. Primary syphilis of the fingers

    OpenAIRE

    Starzycki, Z

    1983-01-01

    Six patients were seen with primary syphilitic chancres on their fingers between 1965 and 1980. Of these, two had bipolar chancres on their fingers and genitals resulting from sexual foreplay. Because syphilis is rarely suspected in such cases diagnostic errors are common.

  2. Presentation = Speech + Slides

    Directory of Open Access Journals (Sweden)

    Derik Badman

    2008-12-01

    Full Text Available Back in October, Aaron Schmidt posted “HOWTO give a good presentation” to his blog walking paper. His second bullet point of “thoughts” on good presentations is: Please don’t fill your slides with words. Find some relevant and pretty pictures to support what you’re saying. You can use the pictures to remind yourself what you’re going [...

  3. Emotional Communication in Finger Braille

    Directory of Open Access Journals (Sweden)

    Yasuhiro Matsuda

    2010-01-01

    Full Text Available We describe analyses of the features of emotions (neutral, joy, sadness, and anger expressed by Finger Braille interpreters and subsequently examine the effectiveness of emotional expression and emotional communication between people unskilled in Finger Braille. The goal is to develop a Finger Braille system to teach emotional expression and a system to recognize emotion. The results indicate the following features of emotional expression by interpreters. The durations of the code of joy were significantly shorter than the durations of the other emotions, the durations of the code of sadness were significantly longer, and the finger loads of anger were significantly larger. The features of emotional expression by unskilled subjects were very similar to those of the interpreters, and the coincidence ratio of emotional communication was 75.1%. Therefore, it was confirmed that people unskilled in Finger Braille can express and communicate emotions using this communication medium.

  4. Slide system for machine tools

    Science.gov (United States)

    Douglass, Spivey S.; Green, Walter L.

    1982-01-01

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  5. Surgery for trigger finger.

    Science.gov (United States)

    Fiorini, Haroldo Junior; Tamaoki, Marcel Jun; Lenza, Mário; Gomes Dos Santos, Joao Baptista; Faloppa, Flávio; Belloti, Joao Carlos

    2018-02-20

    Trigger finger is a common clinical disorder, characterised by pain and catching as the patient flexes and extends digits because of disproportion between the diameter of flexor tendons and the A1 pulley. The treatment approach may include non-surgical or surgical treatments. Currently there is no consensus about the best surgical treatment approach (open, percutaneous or endoscopic approaches). To evaluate the effectiveness and safety of different methods of surgical treatment for trigger finger (open, percutaneous or endoscopic approaches) in adults at any stage of the disease. We searched CENTRAL, MEDLINE, Embase and LILACS up to August 2017. We included randomised or quasi-randomised controlled trials that assessed adults with trigger finger and compared any type of surgical treatment with each other or with any other non-surgical intervention. The major outcomes were the resolution of trigger finger, pain, hand function, participant-reported treatment success or satisfaction, recurrence of triggering, adverse events and neurovascular injury. Two review authors independently selected the trial reports, extracted the data and assessed the risk of bias. Measures of treatment effect for dichotomous outcomes calculated risk ratios (RRs), and mean differences (MDs) or standardised mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CIs). When possible, the data were pooled into meta-analysis using the random-effects model. GRADE was used to assess the quality of evidence for each outcome. Fourteen trials were included, totalling 1260 participants, with 1361 trigger fingers. The age of participants included in the studies ranged from 16 to 88 years; and the majority of participants were women (approximately 70%). The average duration of symptoms ranged from three to 15 months, and the follow-up after the procedure ranged from eight weeks to 23 months.The studies reported nine types of comparisons: open surgery versus steroid injections (two

  6. Contact fatigue in rolling-element bearings

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-06-01

    Full Text Available to the "cyclone pitting effect" also observed in gear teeth \\[1\\]. The initiation of surface cracks under rollin~sliding contact can be significantly accelerated by the presence of stress concentration sites on the contact surf... formed by rolling and rollin~sliding contact fatigue may progress to form a more severe form of damage known as flaking \\[3\\]. This results in the formation of large, irregular pits which cause rapid deterioration...

  7. Covering the Dorsal Finger Defect with Reverse Cross Finger Flap

    Directory of Open Access Journals (Sweden)

    Kaan Gurbuz

    2014-12-01

    Full Text Available Reconstruction of finger extensor zone defects with or without tendon gaps still remains a challenge for surgeons. Although surgical treatments may differ, and range from the use of local, regional, to free flaps, the outcomes for all cases are not satisfactory. In this case report, we present a case of a 3rd finger extensor side crush injury including a defect of Dd (Digit Dorsal 1, Dd2 and Dd3 defects of extensor zones with tendon gap. Tendon gap was reconstructed using m. palmaris longus tendon graft and the defect was covered with reversed cross-finger flap (random pattern with good cosmetic and excellent functional results.

  8. The effects of vibration-reducing gloves on finger vibration

    Science.gov (United States)

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  9. Finger Forces in Clarinet Playing

    Directory of Open Access Journals (Sweden)

    Alex Hofmann

    2016-08-01

    Full Text Available Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17 and professional clarinettists (N = 6 were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 x 2 x 2 design (register: low--high; tempo: slow--fast, dynamics: soft--loud. There was an additional condition controlled by the experimenter, which determined the expression levels (low--high of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions. The melody was performed in three tempo conditions (slow, medium, fast in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean and peak force (Fmax were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N compared to those on other musical instruments (e.g. guitar. Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N.For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N. Such sensor instruments provide useful insights into player

  10. SLIDES: a program to draw slides and posters

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, R.; Schofield, J.

    1977-04-01

    SLIDES is a program which takes text and commands as input and prepares lettered slides and posters. When run on the time-sharing computer, the program can display its output on an interactive graphics terminal; in batch, it can direct its graphical output to a variety of plotters. The program uses DISSPLA graphical subroutines and standard ANL plotter subroutines. This report contains material written for the beginning user, who should be able to produce useful slides or posters by following the examples. This report also serves as a complete reference for the SLIDES program. 4 figures.

  11. Viscous fingering with permeability heterogeneity

    International Nuclear Information System (INIS)

    Tan, C.; Homsy, G.M.

    1992-01-01

    Viscous fingering in miscible displacements in the presence of permeability heterogeneities is studied using two-dimensional simulations. The heterogeneities are modeled as stationary random functions of space with finite correlation scale. Both the variance and scale of the heterogeneities are varied over modest ranges. It is found that the fingered zone grows linearly in time in a fashion analogous to that found in homogeneous media by Tan and Homsy [Phys. Fluids 31, 1330 (1988)], indicating a close coupling between viscous fingering on the one hand and flow through preferentially more permeable paths on the other. The growth rate of the mixing zone increases monotonically with the variance of the heterogeneity, as expected, but shows a maximum as the correlation scale is varied. The latter is explained as a ''resonance'' between the natural scale of fingers in homogeneous media and the correlation scale

  12. Polytopic dystelephalangy of the fingers

    International Nuclear Information System (INIS)

    Sugiura, Y.

    1989-01-01

    An 11-year old girl with dystelephalangy (Kirner deformity) of the right middle, ring, and little, and the left index through little fingers is reported. To the author's best knowledge, such polytopic affection with dystelephalangy has not yet been reported. The parents, one of the siblings and maternal grandfather showed dystelephalangy of the little finger. So, the patient was considered to be a homozygous state of dystelephalangy gene. (orig.)

  13. Getting a grip: different actions and visual guidance of the thumb and finger in precision grasping.

    Science.gov (United States)

    Melmoth, Dean R; Grant, Simon

    2012-10-01

    We manipulated the visual information available for grasping to examine what is visually guided when subjects get a precision grip on a common class of object (upright cylinders). In Experiment 1, objects (2 sizes) were placed at different eccentricities to vary the relative proximity to the participant's (n = 6) body of their thumb and finger contact positions in the final grip orientations, with vision available throughout or only for movement programming. Thumb trajectories were straighter and less variable than finger paths, and the thumb normally made initial contact with the objects at a relatively invariant landing site, but consistent thumb first-contacts were disrupted without visual guidance. Finger deviations were more affected by the object's properties and increased when vision was unavailable after movement onset. In Experiment 2, participants (n = 12) grasped 'glow-in-the-dark' objects wearing different luminous gloves in which the whole hand was visible or the thumb or the index finger was selectively occluded. Grip closure times were prolonged and thumb first-contacts disrupted when subjects could not see their thumb, whereas occluding the finger resulted in wider grips at contact because this digit remained distant from the object. Results were together consistent with visual feedback guiding the thumb in the period just prior to contacting the object, with the finger more involved in opening the grip and avoiding collision with the opposite contact surface. As people can overtly fixate only one object contact point at a time, we suggest that selecting one digit for online guidance represents an optimal strategy for initial grip placement. Other grasping tasks, in which the finger appears to be used for this purpose, are discussed.

  14. Integration of tactile input across fingers in a patient with finger agnosia.

    NARCIS (Netherlands)

    Anema, H.A.; Overvliet, K.E.; Smeets, J.B.J.; Brenner, E.; Dijkerman, H.C.

    2011-01-01

    Finger agnosia has been described as an inability to explicitly individuate between the fingers, which is possibly due to fused neural representations of these fingers. Hence, are patients with finger agnosia unable to keep tactile information perceived over several fingers separate? Here, we tested

  15. Dynamic assembly of Hda and the sliding clamp in the regulation of replication licensing.

    Science.gov (United States)

    Kim, Jin S; Nanfara, Michael T; Chodavarapu, Sundari; Jin, Kyeong S; Babu, Vignesh M P; Ghazy, Mohamed A; Chung, Scisung; Kaguni, Jon M; Sutton, Mark D; Cho, Yunje

    2017-04-20

    Regulatory inactivation of DnaA (RIDA) is one of the major regulatory mechanisms of prokaryotic replication licensing. In RIDA, the Hda-sliding clamp complex loaded onto DNA directly interacts with adenosine triphosphate (ATP)-bound DnaA and stimulates the hydrolysis of ATP to inactivate DnaA. A prediction is that the activity of Hda is tightly controlled to ensure that replication initiation occurs only once per cell cycle. Here, we determined the crystal structure of the Hda-β clamp complex. This complex contains two pairs of Hda dimers sandwiched between two β clamp rings to form an octamer that is stabilized by three discrete interfaces. Two separate surfaces of Hda make contact with the β clamp, which is essential for Hda function in RIDA. The third interface between Hda monomers occludes the active site arginine finger, blocking its access to DnaA. Taken together, our structural and mutational analyses of the Hda-β clamp complex indicate that the interaction of the β clamp with Hda controls the ability of Hda to interact with DnaA. In the octameric Hda-β clamp complex, the inability of Hda to interact with DnaA is a novel mechanism that may regulate Hda function. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. Meetings on Particle Physics - Abstracts and Slides

    International Nuclear Information System (INIS)

    Hirsch, M.; Machado, P.; Bertuzzo, E.; Villanova del Moral, A.; Wingerter, A.; Lellouch, L.; Garron, N.; Portelli, A.; Vulvert, G.; Zerwas, D.; Djouadi, A.; Drieu la Rochelle, G.; Fairbairn, M.; Le Boulc'h, Q.; Dumont, B.; Da Silva, J.; Brax, P.; Weiland, C.; Gelis, F.; Mehtar-Tani, Y.; Epelbaum, T.; Meunier, E.; Dudas, E.; Jezo, T.; Urbano, A.; Smith, C.; Machet, B.; Nezri, E.; Salam, G.; Kosnik, N.; Greynat, D.; Petrov, K.

    2014-01-01

    RPP (Meetings on Particle Physics) annual meetings are aimed at gathering the theoretical particle physicists' community, providing the participants with the opportunity not only to present their research topics, but also to make contact with the latest developments in adjacent fields. RPP-2012 will have a few review talks on topics such as flavors, Higgs bosons, astro-particle physics and cosmology, heavy ions, physics beyond the standard model, and quantum chromodynamics. This document gathers the slides of the presentations, a few presentations are accompanied by an abstract.

  17. No sliding in time

    International Nuclear Information System (INIS)

    Shtengel, Kirill; Nayak, Chetan; Bishara, Waheb; Chamon, Claudio

    2005-01-01

    In this letter, we analyse the following apparent paradox: as has been recently proved by Hastings (2004 Phys. Rev. 69 104431), under a general set of conditions, if a local Hamiltonian has a spectral gap above its (unique) ground state (GS), all connected equal-time correlation functions of local operators decay exponentially with distance. On the other hand, statistical mechanics provides us with examples of 3D models displaying so-called sliding phases (O'Hern et al 1999 Phys. Rev. Lett. 83 2745) which are characterized by the algebraic decay of correlations within 2D layers and exponential decay in the third direction. Interpreting this third direction as time would imply a gap in the corresponding (2+1)D quantum Hamiltonian which would seemingly contradict Hastings' theorem. The resolution of this paradox lies in the non-locality of such a quantum Hamiltonian. (letter to the editor)

  18. Dynamic performance of a C/C composite finger seal in a tilting mode

    Directory of Open Access Journals (Sweden)

    Hailin ZHAO

    2017-08-01

    Full Text Available The complex operating state of aeroengines has an impact on the performance of finger seals. However, little work has been focused on the issue and the dynamic performance of finger seals is also rarely studied. Therefore, a distributed mass equivalent model considering working conditions is proposed in this paper for solving the existing problems. The effects of the fiber bundle density and the preparation direction of the fiber bundle of a C/C composite on the dynamic performance of a finger seal are investigated in rotor tilt based on the proposed model. The difference between the C/C composite finger seal performances under the rotor precession and nutation tilt cases is also investigated. The results show that the fiber bundle density and the preparation direction of the fiber bundle have an influence on the dynamic performance of the finger seal as rotor tilt is considered, and the dynamic performance of the finger seal is different in the two kinds of tilting modes. In addition, a novel method for design of finger seals is presented based on the contact pressure between finger boots and the rotor. Finger seals with good leakage rates and low wear can be acquired in this method.

  19. Moving droplets : The measurement of contact lines

    NARCIS (Netherlands)

    Poelma, C.; Franken, M.J.Z.; Kim, H.; Westerweel, J.

    2014-01-01

    Contact lines are the locations where a gas, liquid and a solid meet. From everyday experience we know that such contact lines can be mobile, for example in the case of a water droplet sliding over a glass surface. However, the continuum description of the flow towards or away from a contact line

  20. Slide Buyers Guide. 1974 Edition.

    Science.gov (United States)

    DeLaurier, Nancy

    Designed for studio art instructors, museum education programs, public libraries, high school teachers, and those who buy slides for teaching art history at the college level, this guide lists sources of slides in the United States and over 20 foreign countries. All U.S. sources are listed first, commercial sources are alphabetical by name and…

  1. Effect of friction on the slide guide in an elevator system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X-g; Li, H-g; Meng, G [State Key Laboratory of Mechanical System and Vibration, Shanghai Jiaotong University, Shanghai 200240 (China)], E-mail: xingang.zhang@gmail.com

    2008-02-15

    The slide guide in an elevator moves in contact against the guide rail. This kind of surface contact exhibits a highly non-linear hysteretic friction behaviour which hampers greatly the riding quality of the elevator system. This paper presents an experimental investigation on this type of phenomenon through measuring the contact friction force between the interface of the slide guide and the rail under different combination of input parameters. The experiment shows frictional behaviours including pre-sliding/gross-sliding regimes, transition behaviour between them, time lag, and velocity (weakening and strengthening) dependence. In addition, it is found that different materials in contact, lubrications and friction duration have strong impacts on evaluation of the friction characteristics. The observations in the test provide an insight into relationships between different friction behaviours and can be used to validate the appropriate theoretical friction models.

  2. Mesofluidic controlled robotic or prosthetic finger

    Science.gov (United States)

    Lind, Randall F; Jansen, John F; Love, Lonnie J

    2013-11-19

    A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

  3. 3D DEM analyses of the 1963 Vajont rock slide

    Science.gov (United States)

    Boon, Chia Weng; Houlsby, Guy; Utili, Stefano

    2013-04-01

    The 1963 Vajont rock slide has been modelled using the distinct element method (DEM). The open-source DEM code, YADE (Kozicki & Donzé, 2008), was used together with the contact detection algorithm proposed by Boon et al. (2012). The critical sliding friction angle at the slide surface was sought using a strength reduction approach. A shear-softening contact model was used to model the shear resistance of the clayey layer at the slide surface. The results suggest that the critical sliding friction angle can be conservative if stability analyses are calculated based on the peak friction angles. The water table was assumed to be horizontal and the pore pressure at the clay layer was assumed to be hydrostatic. The influence of reservoir filling was marginal, increasing the sliding friction angle by only 1.6˚. The results of the DEM calculations were found to be sensitive to the orientations of the bedding planes and cross-joints. Finally, the failure mechanism was investigated and arching was found to be present at the bend of the chair-shaped slope. References Boon C.W., Houlsby G.T., Utili S. (2012). A new algorithm for contact detection between convex polygonal and polyhedral particles in the discrete element method. Computers and Geotechnics, vol 44, 73-82, doi.org/10.1016/j.compgeo.2012.03.012. Kozicki, J., & Donzé, F. V. (2008). A new open-source software developed for numerical simulations using discrete modeling methods. Computer Methods in Applied Mechanics and Engineering, 197(49-50), 4429-4443.

  4. Simulation of Grasping Prismatic Workpieces by a Pneumatically Driven 3-Finger Robotic Gripper

    Directory of Open Access Journals (Sweden)

    Calin-Octavian Miclosina

    2017-12-01

    Full Text Available The paper presents the 3D model of a robotic gripper and a way to determine the value of prehension force by using the SolidWorks software. A set of prismatic workpieces is considered, the contact force finger-workpiece being determined in SolidWorks Motion module for the most disadvantageous case - the heaviest workpiece, as well as von Mises stress that occurs in fingers gripper.

  5. Effects of Roughness and Inertia on Precursors to Frictional Sliding

    Science.gov (United States)

    Robbins, Mark O.; Salerno, K. Michael

    2012-02-01

    Experiments show that when a PMMA block on a surface is normally loaded and driven by an external shear force, contact at the interface is modified in discrete precursor slips prior to steady state sliding.[1] Our simulations use an atomistic model of a rough two-dimensional block in contact with a flat surface to investigate the evolution of stress and displacement along the contact between surfaces. The talk will show how local and global stress conditions govern the initiation of interfacial cracks as well as the spatial extension of the cracked region. Inertia also plays an important role in determining the number and size of slips before sliding and influences the distribution of stresses at the interface. Finally, the geometry of surface asperities also influences the interfacial evolution and the total friction force. The relationship between the interfacial stress state and rupture velocity will also be discussed. [1] S.M. Rubinstein, G. Cohen and J. Fineberg, PRL 98, 226103 (2007)

  6. Condiments and Contact Dermatitis of the Finger - Tips

    Directory of Open Access Journals (Sweden)

    K A Seetharam

    1987-01-01

    Full Text Available Patch tests were undertaken with 16 condiments in 4 groups of patients which included exposed patients, exposed controls, unexposed patients and unexposed controls. As the interpretation of the positive patch test reaction was similar in both the unexposed patients and unexposed controls, these two were combined into one (unexposed groups. Positive reactions were obtained in a variable number of individuals in each of these groups but the tests were generally more frequently positive and more severe in the exposed patients and exposed controls, compared to the unexposed groups. The number of patients showing positive patch tests out of the total number tested in the 3 groups respectively, with each of the agents were, cinnamon 1 (9, 0 (11, 1 (7: coriander 3 (8, 4 (12, 1 (5; clove 2 (8, 3 (16, 0 (1; cumin seeds 3 (8, 4 (11, 1 (6; fennel 3 (9, 4 (16, 0 (1; small cardamom 1 (8,6 (17, 0 (0; large cardamom 3 (8 3 (11, 0 (7; asafoetida 1 (5, 3 (7, 5 (13; Indian cassia 0 (2, 3 (16, 1 (8; mustard seeds 5 (8, 4 (15 0 (2; red chillies 2 (7, 6 (21, 0 (0; turmeric 3 (6, 8 (15 1 (5; tamarind 0 (3, 0 (6, 3 (16; dried mango powder 0 (2, 3 (6, 1 (17; Jaggery 0 (1, 2 (4, 2 (20 and ginger 7 (22, 0 (4, 0 (0. These were considered unikely to be irritant reactions, because in the case of irritant reactions, the frequency of positive reaction is expected to be much more. However, this could not be excluded completely without further studies with standardized antigens and their dilutions.

  7. EMG finger movement classification based on ANFIS

    Science.gov (United States)

    Caesarendra, W.; Tjahjowidodo, T.; Nico, Y.; Wahyudati, S.; Nurhasanah, L.

    2018-04-01

    An increase number of people suffering from stroke has impact to the rapid development of finger hand exoskeleton to enable an automatic physical therapy. Prior to the development of finger exoskeleton, a research topic yet important i.e. machine learning of finger gestures classification is conducted. This paper presents a study on EMG signal classification of 5 finger gestures as a preliminary study toward the finger exoskeleton design and development in Indonesia. The EMG signals of 5 finger gestures were acquired using Myo EMG sensor. The EMG signal features were extracted and reduced using PCA. The ANFIS based learning is used to classify reduced features of 5 finger gestures. The result shows that the classification of finger gestures is less than the classification of 7 hand gestures.

  8. X-Ray Exam: Finger

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Finger KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  9. Sliding hiatal hernia in dogs

    OpenAIRE

    JOLANTA SPUŻAK; KRZYSZTOF KUBIAK; MARCIN JANKOWSKI; MACIEJ GRZEGORY; KAMILA GLIŃSKA-SUCHOCKA; JÓZEF NICPOŃ; VASYL VLIZLO; IGOR MAKSYMOVYCH

    2010-01-01

    Introduction Sliding hiatal hernia is a disorder resulting from a displacement of the abdominal part of the oesophagus and/or a part of the stomach into the thoracic cavity through the oesophageal hiatus of the diaphragm. The disorder may be congenital or acquired. Congenital hernia follows disturbances in the embryonic development. In the literature the predisposition to congenital sliding hiatal hernia is observed in the dogs of shar-pei and chow-chow breeds. Pathogenesis of acquired slidin...

  10. Effects of material properties on soft contact dynamics

    International Nuclear Information System (INIS)

    Khurshid, A.; Malik, M.A.; Ghafoor, A.

    2009-01-01

    The superiority of deformable human fingertips as compared to hard robot gripper fingers for grasping and manipulation has led to a number of investigations with robot hands employing elastomers or materials such as fluids or powders beneath a membrane at the fingertips. In this paper, to analyze the stability of dynamic control of an object grasped between two soft fingertips through a soft interface using the viscoelastic material between the manipulating fingers and a manipulated object is modeled through bond graph method (BGM). The fingers are made viscoelastic by using springs and dampers. Detailed bond graph modeling (BGM) of the contact phenomenon with two soft-finger contacts considered to be placed against each other on the opposite sides of the grasped object as is generally the case in a manufacturing environment is presented. The stiffness of the springs is exploited in order to achieve the stability in the soft-grasping which includes friction between the soft finger contact surfaces and the object, The paper also analyses stability of dynamic control through a soft interface between a manipulating finger and a manipulated object. It is shown in the paper that the system stability depends on the visco-elastic material properties of the soft interface. Method of root locus is used to analyze this phenomenon. The paper shows how the weight of the object coming downward is controlled by the friction between the fingers and the object during the application of contact forces by varying the damping and the stiffness in the soft finger. (author)

  11. Seamless Control of Multi-Fingered Robot Hands Based on Grasp Polyhedrons

    Science.gov (United States)

    Nagase, Kenji; Shirai, Satoshi; Hayashi, Tsuyoshi

    This paper is concerned with a new feedback control design methodology for multi-fingered robot hands applicable to multiple contact situations. As a first step, we especially consider the situations where all the fingers are in contact or not in contact with an object, considering the tasks of catching and releasing the object preceding to or followed by grasping/manipulating the object. Main features of the proposed method are: (1) the direction of the fingertip motion in the non-contact situation is selected to be directly linked to the direction of the object motion and the internal force in the contact situation; (2) by introducing a unified system description for multiple contact situations, a linearizing compensator applicable to multiple contact situations is designed. The controller can handle the tasks with the multiple contact situations by choosing appropriate desired trajectories for the linearizing compensator without switching control architecture. In addition, owing to the selection of the motion in the non-contact situation, all the fingers can approach to the object synchronously along the directions of the object motion and the internal force in the contact situation. A numerical example is shown to prove effectiveness of the proposed method.

  12. Viscous and gravitational fingering in multiphase compositional and compressible flow

    Science.gov (United States)

    Moortgat, Joachim

    2016-03-01

    Viscous and gravitational fingering refer to flow instabilities in porous media that are triggered by adverse mobility or density ratios, respectively. These instabilities have been studied extensively in the past for (1) single-phase flow (e.g., contaminant transport in groundwater, first-contact-miscible displacement of oil by gas in hydrocarbon production), and (2) multi-phase immiscible and incompressible flow (e.g., water-alternating-gas (WAG) injection in oil reservoirs). Fingering in multiphase compositional and compressible flow has received much less attention, perhaps due to its high computational complexity. However, many important subsurface processes involve multiple phases that exchange species. Examples are carbon sequestration in saline aquifers and enhanced oil recovery (EOR) by gas or WAG injection below the minimum miscibility pressure. In multiphase flow, relative permeabilities affect the mobility contrast for a given viscosity ratio. Phase behavior can also change local fluid properties, which can either enhance or mitigate viscous and gravitational instabilities. This work presents a detailed study of fingering behavior in compositional multiphase flow in two and three dimensions and considers the effects of (1) Fickian diffusion, (2) mechanical dispersion, (3) flow rates, (4) domain size and geometry, (5) formation heterogeneities, (6) gravity, and (7) relative permeabilities. Results show that fingering in compositional multiphase flow is profoundly different from miscible conditions and upscaling techniques used for the latter case are unlikely to be generalizable to the former.

  13. Friction and universal contact area law for randomly rough viscoelastic contacts.

    Science.gov (United States)

    Scaraggi, M; Persson, B N J

    2015-03-18

    We present accurate numerical results for the friction force and the contact area for a viscoelastic solid (rubber) in sliding contact with hard, randomly rough substrates. The rough surfaces are self-affine fractal with roughness over several decades in length scales. We calculate the contribution to the friction from the pulsating deformations induced by the substrate asperities. We also calculate how the area of real contact, A(v, p), depends on the sliding speed v and on the nominal contact pressure p, and we show how the contact area for any sliding speed can be obtained from a universal master curve A(p). The numerical results are found to be in good agreement with the predictions of an analytical contact mechanics theory.

  14. Testing of newly developed functional surfaces under pure sliding conditions

    DEFF Research Database (Denmark)

    Godi, Alessandro; Mohaghegh, Kamran; Grønbæk, J.

    2013-01-01

    the surfaces in an industrial context. In this paper, a number of experimental tests were performed using a novel test rig, called axial sliding test, simulating the contact of surfaces under pure sliding conditions. The aim of the experiments is to evaluate the frictional behavior of a new typology...... of textured surfaces, the so-called multifunctional surfaces, characterized by a plateau area able to bear loads and a deterministic pattern of lubricant pockets. Six surface typologies, namely three multifunctional and three machined using classical processes, were chosen to slide against a mirror....... The results comparison showed clearly how employing multifunctional surfaces can reduce friction forces up to 50 % at high normal loads compared to regularly ground or turned surfaces. Friction coefficients approximately equal to 0.12 were found for classically machined surfaces, whereas the values were 0...

  15. Binder extrusion of sliding wear of WC-Co alloys

    International Nuclear Information System (INIS)

    Larsen-Basse, J.

    1985-01-01

    It has previously been proposed that preferential removal of the cobalt binder is an important mechanism in the abrasive wear of cemented carbides in the WC-Co family. It is here demonstrated that binder extrusion occurs also in metal-to-metal sliding wear contacts. The wear scar generated by sliding a hardened steel ball repeatedly over a polished WC-Co surface was studied by SEM. The extruded cobalt fragments accumulate by surface defects, such as cracks caused by the sliding loaded ball, and gradual microfragmentation of the carbide grains follows. The energy required to extrude the cobalt and cause the gradual change in surface layer microstructure is provided by the frictional forces

  16. Analysis of the Optical Properties of Screen-Printed and Aerosol-Printed and Plated Fingers of Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    R. Woehl

    2008-01-01

    Full Text Available One main efficiency loss in industrial solar cells is the shading of the cell caused by the metal front side contacts. With the aerosol-printing technique plus an additional light-induced plating (LIP step, not only is the geometrical contact width narrowed compared to screen-printed contacts but also the shape of the finger changes. In this work, the effective shading of different finger types is analysed with two different measurement methods. The essential parameter for characterising the finger is the effective width which can be reduced drastically compared to the geometrical width due to total internal reflection at the glass-air layer and the reflection from the roundish edges of the contact fingers into the cell. This parameter was determined with different methods. It could be shown that for aerosol-printed fingers the effective (optical width is only 38% of its geometrical width, while for standard screen-printed fingers it is 47%. The measured values are compared to a theoretical model for an aerosol-printed and plated finger and are in good agreement.

  17. Use of near field acoustic levitation sliding contact

    OpenAIRE

    Stolarski, TA; Woolliscroft, CI

    2007-01-01

    This paper presents an investigation into producing self-levitation effect using piezo-electric actuators (PZT). Self-levitation has been demonstrated and results are presented and discussed. A relationship between the levitation distance and weight of the levitating sample has been found. In addition the orientation and position of the PZTs has been found to affect the levitation distance. Modal shapes of the vibration plates used have been produced through modelling annd found to accurately...

  18. [When doors slam, fingers jam!].

    Science.gov (United States)

    Claudet, I; Toubal, K; Carnet, C; Rekhroukh, H; Zelmat, B; Debuisson, C; Cahuzac, J-P

    2007-08-01

    Epidemiological analysis in a universitary paediatric emergency unit of children admitted after accidental injuries resulting from fingers crushed in a door. Prospective, descriptive cohort study from September 6th, 2004 to July 1st, 2005 included all children admitted for finger injuries crushed in a non-automatic door. included accidents due to automatic doors, toy's or refrigerator doors, families who refused to participate to the study or families who had left the waiting area before medical examination. Collected data were patient and family characteristics, accident characteristics and its management. Three hundred and forty children affected by 427 digital lesions were included. The mean age was 5.5+/-3.8 years (range 4 months - 15.5 years). Male/female ratio was equal to 1.2: 1. Fifty-eight percent of patients belonged to families composed of 3 or more siblings. Ninety-three per cent of families came to hospital within the first 2 hours after the accident (mean delay 99+/-162 min, median range 54 minutes). Location of the accident was: domestic (62%, at home (64%)), at school (17%). Locations within the home were: the bedroom (33%), bathroom and toilets (21%). An adult was present in 75% of cases and responsible for the trauma in 25% of accidents, another child in 44%. The finger or fingers were trapped on the hinge side in 57% of patients. No specific safeguard devices were used by 94% of families. Among victims, 20% had several crushed digits; left and right hand were injured with an equal frequency. The commonest involved digits were: the middle finger (29%), the ring finger (23%). The nail plate was damaged in 60% of digital lesions, associated with a wound (50%), a distal phalanx fracture (P3) (12%). Six children had a partial or complete amputation of P3, 2 children a lesion of the extensor tendon, 1 child had a rupture of the external lateral ligament. Three percent of children required an admission to the paediatric orthopaedic surgery unit. Post

  19. Mapping stain distribution in pathology slides using whole slide imaging

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Yeh

    2014-01-01

    Full Text Available Background: Whole slide imaging (WSI offers a novel approach to digitize and review pathology slides, but the voluminous data generated by this technology demand new computational methods for image analysis. Materials and Methods: In this study, we report a method that recognizes stains in WSI data and uses kernel density estimator to calculate the stain density across the digitized pathology slides. The validation study was conducted using a rat model of acute cardiac allograft rejection and another rat model of heart ischemia/reperfusion injury. Immunohistochemistry (IHC was conducted to label ED1 + macrophages in the tissue sections and the stained slides were digitized by a whole slide scanner. The whole slide images were tessellated to enable parallel processing. Pixel-wise stain classification was conducted to classify the IHC stains from those of the background and the density distribution of the identified IHC stains was then calculated by the kernel density estimator. Results: The regression analysis showed a correlation coefficient of 0.8961 between the number of IHC stains counted by our stain recognition algorithm and that by the manual counting, suggesting that our stain recognition algorithm was in good agreement with the manual counting. The density distribution of the IHC stains showed a consistent pattern with those of the cellular magnetic resonance (MR images that detected macrophages labeled by ultrasmall superparamagnetic iron-oxide or micron-sized iron-oxide particles. Conclusions: Our method provides a new imaging modality to facilitate clinical diagnosis. It also provides a way to validate/correlate cellular MRI data used for tracking immune-cell infiltration in cardiac transplant rejection and cardiac ischemic injury.

  20. Modelling of the Contact Condition at the Tool/Matrix Interface in Friction Stir Welding

    DEFF Research Database (Denmark)

    Schmidt, Henrik Nikolaj Blich; Hattel, Jesper; Wert, John

    2003-01-01

    a known contact condition at the contact interface, e.g. either as pure sliding or sticking. The present model uses Coulomb’s law of friction for the sliding condition and the material yield shear stress for the sticking condition to model the contact forces. The model includes heat generation...

  1. Impact of Finger Type in Fingerprint Authentication

    Science.gov (United States)

    Gafurov, Davrondzhon; Bours, Patrick; Yang, Bian; Busch, Christoph

    Nowadays fingerprint verification system is the most widespread and accepted biometric technology that explores various features of the human fingers for this purpose. In general, every normal person has 10 fingers with different size. Although it is claimed that recognition performance with little fingers can be less accurate compared to other finger types, to our best knowledge, this has not been investigated yet. This paper presents our study on the topic of influence of the finger type into fingerprint recognition performance. For analysis we employ two fingerprint verification software packages (one public and one commercial). We conduct test on GUC100 multi sensor fingerprint database which contains fingerprint images of all 10 fingers from 100 subjects. Our analysis indeed confirms that performance with small fingers is less accurate than performance with the others fingers of the hand. It also appears that best performance is being obtained with thumb or index fingers. For example, performance deterioration from the best finger (i.e. index or thumb) to the worst fingers (i.e. small ones) can be in the range of 184%-1352%.

  2. Optimization for Guitar Fingering on Single Notes

    Science.gov (United States)

    Itoh, Masaru; Hayashida, Takumi

    This paper presents an optimization method for guitar fingering. The fingering is to determine a unique combination of string, fret and finger corresponding to the note. The method aims to generate the best fingering pattern for guitar robots rather than beginners. Furthermore, it can be applied to any musical score on single notes. A fingering action can be decomposed into three motions, that is, a motion of press string, release string and move fretting hand. The cost for moving the hand is estimated on the basis of Manhattan distance which is the sum of distances along fret and string directions. The objective is to minimize the total fingering costs, subject to fret, string and finger constraints. As a sequence of notes on the score forms a line on time series, the optimization for guitar fingering can be resolved into a multistage decision problem. Dynamic programming is exceedingly effective to solve such a problem. A level concept is introduced into rendering states so as to make multiple DP solutions lead a unique one among the DP backward processes. For example, if two fingerings have the same value of cost at different states on a stage, then the low position would be taken precedence over the high position, and the index finger would be over the middle finger.

  3. Direct Numerical Simulation of Fingering Instabilities in Coating Flows

    Science.gov (United States)

    Eres, Murat H.; Schwartz, Leonard W.

    1998-11-01

    We consider stability and finger formation in free surface flows. Gravity driven downhill drainage and temperature gradient driven climbing flows are two examples of such problems. The former situation occurs when a mound of viscous liquid on a vertical wall is allowed to flow. Constant surface shear stress due to temperature gradients (Marangoni stress) can initiate the latter problem. The evolution equations are derived using the lubrication approximation. We also include the effects of finite-contact angles in the evolution equations using a disjoining pressure model. Evolution equations for both problems are solved using an efficient alternating-direction-implicit method. For both problems a one-dimensional base state is established, that is steady in a moving reference frame. This base state is unstable to transverse perturbations. The transverse wavenumbers for the most rapidly growing modes are found through direct numerical solution of the nonlinear evolution equations, and are compared with published experimental results. For a range of finite equilibrium contact angles, the fingers can grow without limit leading to semi-finite steady fingers in a moving coordinate system. A computer generated movie of the nonlinear simulation results, for several sets of input parameters, will be shown.

  4. Integration of tactile input across fingers in a patient with finger agnosia.

    Science.gov (United States)

    Anema, Helen A; Overvliet, Krista E; Smeets, Jeroen B J; Brenner, Eli; Dijkerman, H Chris

    2011-01-01

    Finger agnosia has been described as an inability to explicitly individuate between the fingers, which is possibly due to fused neural representations of these fingers. Hence, are patients with finger agnosia unable to keep tactile information perceived over several fingers separate? Here, we tested a finger agnosic patient (GO) on two tasks that measured the ability to keep tactile information simultaneously perceived by individual fingers separate. In experiment 1 GO performed a haptic search task, in which a target (the absence of a protruded line) needed to be identified among distracters (protruded lines). The lines were presented simultaneously to the fingertips of both hands. Similarly to the controls, her reaction time decreased when her fingers were aligned as compared to when her fingers were stretched and in an unaligned position. This suggests that she can keep tactile input from different fingers separate. In experiment two, GO was required to judge the position of a target tactile stimulus to the index finger, relatively to a reference tactile stimulus to the middle finger, both in fingers uncrossed and crossed position. GO was able to indicate the relative position of the target stimulus as well as healthy controls, which indicates that she was able to keep tactile information perceived by two neighbouring fingers separate. Interestingly, GO performed better as compared to the healthy controls in the finger crossed condition. Together, these results suggest the GO is able to implicitly distinguish between tactile information perceived by multiple fingers. We therefore conclude that finger agnosia is not caused by minor disruptions of low-level somatosensory processing. These findings further underpin the idea of a selective impaired higher order body representation restricted to the fingers as underlying cause of finger agnosia. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Viscous Fingering in Deformable Systems

    Science.gov (United States)

    Guan, Jian Hui; MacMinn, Chris

    2017-11-01

    Viscous fingering is a classical hydrodynamic instability that occurs when an invading fluid is injected into a porous medium or a Hele-Shaw cell that contains a more viscous defending fluid. Recent work has shown that viscous fingering in a Hele-Shaw cell is supressed when the flow cell is deformable. However, the mechanism of suppression relies on a net volumetric expansion of the flow area. Here, we study flow in a novel Hele-Shaw cell consisting of a rigid bottom plate and a flexible top plate that deforms in a way that is volume-conserving. In other words, fluid injection into the flow cell leads to a local expansion of the flow area (outward displacement of the flexible surface) that must be coupled to non-local contraction (inward displacement of the flexible surface). We explore the impact of this volumetric confinement on steady viscous flow and on viscous fingering. We would like to thank EPSRC for the funding for this work.

  6. Slide-based ergometer rowing

    DEFF Research Database (Denmark)

    Vinther, Anders; Alkjær, T; Kanstrup, I-L

    2012-01-01

    Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with sy...

  7. Linear Motor With Air Slide

    Science.gov (United States)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  8. SlideDog / Siim Sein

    Index Scriptorium Estoniae

    Sein, Siim

    2015-01-01

    SlideDog on multimeediumi esitluse tööriist, mis võimaldab ühendada PowerPointi esitlused, PDF-failid, Prezi esitlused, videoklipid, helifailid, veebilehed ja palju muud üheks sujuvaks esitluskogemuseks konverentsil, seminaril või muul üritusel

  9. Language Contact.

    Science.gov (United States)

    Nelde, Peter Hans

    1995-01-01

    Examines the phenomenon of language contact and recent trends in linguistic contact research, which focuses on language use, language users, and language spheres. Also discusses the role of linguistic and cultural conflicts in language contact situations. (13 references) (MDM)

  10. Current status of ultrasonography of the finger

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seun Ah; Kim, Baek Hyun [Dept. of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of); Kim, Seon Jeong [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of); Kim, Ji Na [Dept. of Radiology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon (Korea, Republic of); Park, Sun Young [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of); Choi, Kyung Hee [Incheon Baek Hospital, Incheon (Korea, Republic of)

    2016-03-15

    The recent development of advanced high-resolution transducers has enabled the fast, easy, and dynamic ultrasonographic evaluation of small, superficial structures such as the finger. In order to best exploit these advances, it is important to understand the normal anatomy and the basic pathologies of the finger, as exemplified by the following conditions involving the dorsal, volar, and lateral sections of the finger: sagittal band injuries, mallet finger, and Boutonnière deformity (dorsal aspect); flexor tendon tears, trigger finger, and volar plate injuries (volar aspect); gamekeeper’s thumb (Stener lesions) and other collateral ligament tears (lateral aspect); and other lesions. This review provides a basis for understanding the ultrasonography of the finger and will therefore be useful for radiologists.

  11. Current status of ultrasonography of the finger

    Directory of Open Access Journals (Sweden)

    Seun Ah Lee

    2016-04-01

    Full Text Available The recent development of advanced high-resolution transducers has enabled the fast, easy, and dynamic ultrasonographic evaluation of small, superficial structures such as the finger. In order to best exploit these advances, it is important to understand the normal anatomy and the basic pathologies of the finger, as exemplified by the following conditions involving the dorsal, volar, and lateral sections of the finger: sagittal band injuries, mallet finger, and Boutonnière deformity (dorsal aspect; flexor tendon tears, trigger finger, and volar plate injuries (volar aspect; gamekeeper’s thumb (Stener lesions and other collateral ligament tears (lateral aspect; and other lesions. This review provides a basis for understanding the ultrasonography of the finger and will therefore be useful for radiologists.

  12. Mechanism of sliding friction on a film-terminated fibrillar interface.

    Science.gov (United States)

    Shen, Lulin; Jagota, Anand; Hui, Chung-Yuen

    2009-03-03

    We study the mechanism of sliding friction on a film-terminated fibrillar interface. It has been shown that static friction increases significantly with increasing spacing between fibrils, and with increasing rate of loading. However, surprisingly, the sliding friction remains substantially unaffected both by geometry and by the rate of loading. The presence of the thin terminal film is a controlling factor in determining the sliding friction. Experimentally, and by a simple model in which the indenter is held up by the tension in the thin film, we show how the indenter maintains a nearly constant contact area that is independent of the fibril spacing, resulting in constant sliding friction. By this mechanism, using the film-terminated structure, one can enhance the static friction without affecting the sliding behavior.

  13. In the finger it lingers

    Directory of Open Access Journals (Sweden)

    Irfan Mohamad

    2017-08-01

    Full Text Available A previously healthy 80-year-old woman presented with a history of a thorn prick injury over the distal phalange of her left finger obtained while gardening two months ago. She claimed to have a non-healing cut with a nodular lesion, which progressively increased in size, extending upwards towards the region of her left arm. There was no fever or palpable lymph nodes in the axillary region. She had been prescribed antibiotics from the local hospital but her condition did not improve.

  14. Instrumented Glove Measures Positions Of Fingers

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1993-01-01

    Glove instrumented with flat membrane potentiometers to obtain crude measurements of relative positions of fingers. Resistance of each potentiometer varies with position of associated finger; translator circuit connected to each potentiometer converts analog reading to 1 of 10 digital levels. Digitized outputs from all fingers fed to indicating, recording, and/or data-processing equipment. Gloves and circuits intended for use in biomedical research, training in critical manual tasks, and other specialized applications.

  15. Generating and analyzing synthetic finger vein images

    OpenAIRE

    Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

    2014-01-01

    Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have posed challenges in exploring this technology for large scale applications. This paper details the first such attempt to synthesize finger-vein images and presents analysis of synthesized images fo...

  16. Application of autoradiography in finger print analysis

    International Nuclear Information System (INIS)

    Stverak, B.; Kopejtko, J.; Simek, J.

    1983-01-01

    In order to broaden the possibilities of developing latent finger prints a tracer technique has been developed using sup(110m)Ag and autoradiographic imaging. This method has been tested on glass, paper and certain plastics. On paper it is possible to visualize finger prints even after previous development using Ninhydrin. It is shown that usable finger prints may be obtained also from materials from which they cannot be obtained using classical methods, e.g., polyethylene and simulated leather. (author)

  17. Role of protein structure and the role of individual fingers in zinc finger protein-DNA recognition: a molecular dynamics simulation study and free energy calculations

    Science.gov (United States)

    Hamed, Mazen Y.

    2018-05-01

    Molecular dynamics and MM_GBSA energy calculations on various zinc finger proteins containing three and four fingers bound to their target DNA gave insights into the role of each finger in the DNA binding process as part of the protein structure. The wild type Zif 268 (PDB code: 1AAY) gave a ΔG value of - 76.1 (14) kcal/mol. Zinc fingers ZF1, ZF2 and ZF3 were mutated in one experiment and in another experiment one finger was cut and the rest of the protein was studied for binding. The ΔΔG values for the Zinc Finger protein with both ZF1 and ZF2 mutated was + 80 kcal/mol, while mutating only ZF1 the ΔΔG value was + 52 kcal/mol (relative to the wild type). Cutting ZF3 and studying the protein consisting only of ZF1 linked to ZF2 gave a ΔΔG value of + 68 kcal/mol. Upon cutting ZF1, the resulting ZF2 linked to ZF3 protein gave a ΔΔG value of + 41 kcal/mol. The above results shed light on the importance of each finger in the binding process, especially the role of ZF1 as the anchoring finger followed in importance by ZF2 and ZF3. The energy difference between the binding of the wild type protein Zif268 (1AAY) and that for individual finger binding to DNA according to the formula: ΔΔGlinkers, otherstructuralfactors = ΔGzif268 - (ΔGF1+F2+F3) gave a value = - 44.5 kcal/mol. This stabilization can be attributed to the contribution of linkers and other structural factors in the intact protein in the DNA binding process. DNA binding energies of variant proteins of the wild type Zif268 which differ in their ZF1 amino acid sequence gave evidence of a good relationship between binding energy and recognition and specificity, this finding confirms the reported vital role of ZF1 in the ZF protein scanning and anchoring to the target DNA sequence. The role of hydrogen bonds in both specific and nonspecific amino acid-DNA contacts is discussed in relation to mutations. The binding energies of variant Zinc Finger proteins confirmed the role of ZF1 in the recognition

  18. Discrete-time nonlinear sliding mode controller

    African Journals Online (AJOL)

    user

    Keywords: Discrete-time delay system, Sliding mode control, nonlinear sliding ... of engineering systems such as chemical process control, delay in the actuator ...... instrumentation from Motilal Nehru National Institute of Technology (MNNIT),.

  19. Sliding as Hillside Phenomenon in the North Eastern Part of Kosova

    OpenAIRE

    , S. Bulliqi; , F. Isufi; , F. Humolli

    2016-01-01

    In the complex of the side phenomena of the north eastern part of Kosova, sliding who appear in a quite different dimensions play an important role in the landscape modeling; in some territories are ran in into a strong collapse, especially during tectonic abruptness. Quite developed sliding show during the tectonic contacts of magma rocks with those Terrigene, thus during the destruction streak including scrapped colluviums- proluvial materials and those diluVia of the scab conveyance. The w...

  20. Optical Three-Axis Tactile Sensor for Robotic Fingers

    OpenAIRE

    Ohka, Masahiro; Takata, Jumpei; Kobayashi, Hiroaki; Suzuki, Hirofumi; Morisawa, Nobuyuki; Yussof, Hanafiah Bin

    2008-01-01

    A new three-axis tactile sensor to be mounted on multi-fingered hands is developed based on the principle of an optical waveguide-type tactile sensor comprised of an acrylic hemispherical dome, a light source, an array of rubber sensing elements, and a CCD camera. The sensing element of the present tactile sensor includes one columnar feeler and eight conical feelers. A three-axis force applied to the tip of the sensing element is detected by the contact areas of the conical feelers, which ma...

  1. A three-fingered, touch-sensitive, metrological micro-robotic assembly tool

    International Nuclear Information System (INIS)

    Torralba, Marta; Hastings, D J; Thousand, Jeffery D; Nowakowski, Bartosz K; Smith, Stuart T

    2015-01-01

    This article describes a metrological, robotic hand to manipulate and measure micrometer size objects. The presented work demonstrates not only assembly operations, but also positioning control and metrology capability. Sample motion is achieved by a commercial positioning stage, which provides XYZ-displacements for assembly of components. A designed and manufactured gripper tool that incorporates 21 degrees-of-freedom for independent alignment of actuators, sensors, and the three fingers of this hand is presented. These fingers can be opened and closed by piezoelectric actuators through levered flexures providing an 80 μm displacement range measured with calibrated opto-interrupter based, knife-edge sensors. The operational ends of the fingers comprise of a quartz tuning fork with a 7 μm diameter 3.2 mm long carbon fiber extending from the end of one tuning fork tine. Finger-tip force-sensing is achieved by the monitoring of individual finger resonances typically at around 32 kHz. Experimental results included are focused on probe performance analysis. Pick and place operation using the three fingers is demonstrated with all fingers being continuously oscillated, a capability not possible with the previous single or two finger tweezer type designs. By monitoring electrical feedback during pick and place operations, changes in the response of the three probes demonstrate the ability to identify both grab and release operations. Component metrology has been assessed by contacting different micro-spheres of diameters 50(±7.5) μm, 135(±20) μm, and 140(±20) μm. These were measured by the micro robot to have diameters of 67, 133, and 126 μm respectively with corresponding deviations of 4.2, 4.9, and 4.3 μm. This deviation in the measured results was primarily due to the manual, joystick-based, contacting of the fingers, difficulties associated with centering the components to the axis of the hand, and lower contact sensitivity for the smallest sphere

  2. Equilibrium contact angle or the most-stable contact angle?

    Science.gov (United States)

    Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

    2014-04-01

    It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation. © 2013 Elsevier B.V. All rights reserved.

  3. Generating and analyzing synthetic finger vein images

    NARCIS (Netherlands)

    Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

    2014-01-01

    Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have

  4. Surgical Treatment of Trigger Finger: Open Release

    Directory of Open Access Journals (Sweden)

    Firat Ozan

    2016-01-01

    Full Text Available In this study, open A1 pulley release results were evaluated in patients with a trigger finger diagnosis. 45 patients (29 females, 16 males, mean age 50.7 ± 11.9; range (24-79, 45 trigger fingers were released via open surgical technique. On the 25 of 45 cases were involved in the right hand and 16 of them were at the thumb, 2 at index, 6 at the middle and 1 at ring finger. Similarly, at the left hand, 15 of 20 cases were at the thumb, 1 at the index finger, 2 at middle finger and 2 at ring finger. Average follow-up time was 10.2 ± 2.7 (range, 6-15 months. Comorbidities in patients were; diabetes mellitus at 6 cases (13.3%, hypertension at 11 cases (24.4%, hyperthyroidism at 2 cases (4.4%, dyslipidemia at 2 cases (4.4% and lastly 2 cases had carpal tunnel syndrome operation. The mean time between the onset of symptoms to surgery was 6.9 ± 4.8 (range, 2-24 months. Patient satisfaction was very good in 34 cases (75.4% and good in 11 (24.6% patients. The distance between the pulpa of the operated finger and the palm was normal in every case postoperatively. We have not encountered any postoperative complications. We can recommend that; A1 pulley release via open incision is an effective and reliable method in trigger finger surgery.

  5. Number to finger mapping is topological.

    NARCIS (Netherlands)

    Plaisier, M.A.; Smeets, J.B.J.

    2011-01-01

    It has been shown that humans associate fingers with numbers because finger counting strategies interact with numerical judgements. At the same time, there is evidence that there is a relation between number magnitude and space as small to large numbers seem to be represented from left to right. In

  6. Hybrid Photoacoustic/Ultrasound Tomograph for Real-Time Finger Imaging.

    Science.gov (United States)

    Oeri, Milan; Bost, Wolfgang; Sénégond, Nicolas; Tretbar, Steffen; Fournelle, Marc

    2017-10-01

    We report a target-enclosing, hybrid tomograph with a total of 768 elements based on capacitive micromachined ultrasound transducer technology and providing fast, high-resolution 2-D/3-D photoacoustic and ultrasound tomography tailored to finger imaging. A freely programmable ultrasound beamforming platform sampling data at 80 MHz was developed to realize plane wave transmission under multiple angles. A multiplexing unit enables the connection and control of a large number of elements. Fast image reconstruction is provided by GPU processing. The tomograph is composed of four independent and fully automated movable arc-shaped transducers, allowing imaging of all three finger joints. The system benefits from photoacoustics, yielding high optical contrast and enabling visualization of finger vascularization, and ultrasound provides morphologic information on joints and surrounding tissue. A diode-pumped, Q-switched Nd:YAG laser and an optical parametric oscillator are used to broaden the spectrum of emitted wavelengths to provide multispectral imaging. Custom-made optical fiber bundles enable illumination of the region of interest in the plane of acoustic detection. Precision in positioning of the probe in motion is ensured by use of a motor-driven guide slide. The current position of the probe is encoded by the stage and used to relate ultrasound and photoacoustic signals to the corresponding region of interest of the suspicious finger joint. The system is characterized in phantoms and a healthy human finger in vivo. The results obtained promise to provide new opportunities in finger diagnostics and establish photoacoustic/ultrasound-tomography in medical routine. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  7. Adaptive Fuzzy Integral Sliding-Mode Regulator for Induction Motor Using Nonlinear Sliding Surface

    OpenAIRE

    Yong-Kun Lu

    2015-01-01

    An adaptive fuzzy integral sliding-mode controller using nonlinear sliding surface is designed for the speed regulator of a field-oriented induction motor drive in this paper. Combining the conventional integral sliding surface with fractional-order integral, a nonlinear sliding surface is proposed for the integral sliding-mode speed control, which can overcome the windup problem and the convergence speed problem. An adaptive fuzzy control term is utilized to approximate the uncertainty. The ...

  8. Generic Automated Multi-function Finger Design

    Science.gov (United States)

    Honarpardaz, M.; Tarkian, M.; Sirkett, D.; Ölvander, J.; Feng, X.; Elf, J.; Sjögren, R.

    2016-11-01

    Multi-function fingers that are able to handle multiple workpieces are crucial in improvement of a robot workcell. Design automation of multi-function fingers is highly demanded by robot industries to overcome the current iterative, time consuming and complex manual design process. However, the existing approaches for the multi-function finger design automation are unable to entirely meet the robot industries’ need. This paper proposes a generic approach for design automation of multi-function fingers. The proposed approach completely automates the design process and requires no expert skill. In addition, this approach executes the design process much faster than the current manual process. To validate the approach, multi-function fingers are successfully designed for two case studies. Further, the results are discussed and benchmarked with existing approaches.

  9. Friction behavior of glass and metals in contact with glass in various environments

    Science.gov (United States)

    Buckley, D. H.

    1973-01-01

    Sliding friction experiments have been conducted for heat-resistant glass and metals in contact with glass. These experiments were conducted in various environments including vacuum, moist air, dry air, octane, and stearic acid in hexadecane. Glass exhibited a higher friction force in moist air than it did in vacuum when in sliding contact with itself. The metals, aluminum, iron, and gold, all exhibited the same friction coefficient when sliding on glass in vacuum as glass sliding on glass. Gold-to-glass contacts were extremely sensitive to the environment despite the relative chemical inertness of gold.

  10. Electrokinetic Control of Viscous Fingering

    Science.gov (United States)

    Mirzadeh, Mohammad; Bazant, Martin Z.

    2017-10-01

    We present a theory of the interfacial stability of two immiscible electrolytes under the coupled action of pressure gradients and electric fields in a Hele-Shaw cell or porous medium. Mathematically, our theory describes a phenomenon of "vector Laplacian growth," in which the interface moves in response to the gradient of a vector-valued potential function through a generalized mobility tensor. Physically, we extend the classical Saffman-Taylor problem to electrolytes by incorporating electrokinetic (EK) phenomena. A surprising prediction is that viscous fingering can be controlled by varying the injection ratio of electric current to flow rate. Beyond a critical injection ratio, stability depends only upon the relative direction of flow and current, regardless of the viscosity ratio. Possible applications include porous materials processing, electrically enhanced oil recovery, and EK remediation of contaminated soils.

  11. Attractors near grazing–sliding bifurcations

    International Nuclear Information System (INIS)

    Glendinning, P; Kowalczyk, P; Nordmark, A B

    2012-01-01

    In this paper we prove, for the first time, that multistability can occur in three-dimensional Fillipov type flows due to grazing–sliding bifurcations. We do this by reducing the study of the dynamics of Filippov type flows around a grazing–sliding bifurcation to the study of appropriately defined one-dimensional maps. In particular, we prove the presence of three qualitatively different types of multiple attractors born in grazing–sliding bifurcations. Namely, a period-two orbit with a sliding segment may coexist with a chaotic attractor, two stable, period-two and period-three orbits with a segment of sliding each may coexist, or a non-sliding and period-three orbit with two sliding segments may coexist

  12. Differing Dynamics of Intrapersonal and Interpersonal Coordination: Two-finger and Four-Finger Tapping Experiments.

    Directory of Open Access Journals (Sweden)

    Kentaro Kodama

    Full Text Available Finger-tapping experiments were conducted to examine whether the dynamics of intrapersonal and interpersonal coordination systems can be described equally by the Haken-Kelso-Bunz model, which describes inter-limb coordination dynamics. This article reports the results of finger-tapping experiments conducted in both systems. Two within-subject factors were investigated: the phase mode and the number of fingers. In the intrapersonal experiment (Experiment 1, the participants were asked to tap, paced by a gradually hastening auditory metronome, looking at their fingers moving, using the index finger in the two finger condition, or the index and middle finger in the four-finger condition. In the interpersonal experiment (Experiment 2, pairs of participants performed the task while each participant used the outside hand, tapping with the index finger in the two finger condition, or the index and middle finger in the four-finger condition. Some results did not agree with the HKB model predictions. First, from Experiment 1, no significant difference was observed in the movement stability between the in-phase and anti-phase modes in the two finger condition. Second, from Experiment 2, no significant difference was found in the movement stability between the in-phase and anti-phase mode in the four-finger condition. From these findings, different coordination dynamics were inferred between intrapersonal and interpersonal coordination systems against prediction from the previous studies. Results were discussed according to differences between intrapersonal and interpersonal coordination systems in the availability of perceptual information and the complexity in the interaction between limbs derived from a nested structure.

  13. An Axial Sliding Test for machine elements surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran

    2012-01-01

    are necessary: a press to provide the normal pressure and a tensile machine to perform the axial movements. The test is calibrated so that the correspondence between the normal pressure and the container advancement is found. Finally, preliminary tests are carried out involving a multifunctional and a fine......Throughout the years, it has become more and more important to find new methods for reducing friction and wear occurrence in machine elements. A possible solution is found in texturing the surfaces under tribological contact, hence the development and spread of plateau-honed surface for cylinder...... liners. To prove the efficacy of a particular textured surface, it is paramount to perform experimental tests under controlled laboratory conditions. In this paper a new test rig simulating pure sliding conditions is presented, dubbed Axial Sliding Test. It presents four major components: a rod, a sleeve...

  14. Applications of sliding mode control

    CERN Document Server

    Ghommam, Jawhar; Zhu, Quanmin

    2017-01-01

    This book presents essential studies and applications in the context of sliding mode control, highlighting the latest findings from interdisciplinary theoretical studies, ranging from computational algorithm development to representative applications. Readers will learn how to easily tailor the techniques to accommodate their ad hoc applications. To make the content as accessible as possible, the book employs a clear route in each paper, moving from background to motivation, to quantitative development (equations), and lastly to case studies/illustrations/tutorials (simulations, experiences, curves, tables, etc.). Though primarily intended for graduate students, professors and researchers from related fields, the book will also benefit engineers and scientists from industry. .

  15. Impedance Studies for VMTSA Module of LHC Equipped with RF Fingers

    CERN Document Server

    Kononenko, O; Métral, E; Grudiev, A; Caspers, F

    2013-01-01

    During the 2011 LHC run it was found that beam-induced heating causes many issues for accelerator components. Particularly some of the double-bellow modules, called VMTSA modules, were found to have deformed RF fingers and a broken spring, which had ensured good contact between them and a central insert. Impedance studies have been performed for different types of nonconformities. It was found that even a small gap between the fingers and a central insert could be fatal for the VMTSA operation. Results of this study were an input for the further thermal analysis.

  16. Lessons Learnt and Mitigation Measures for the CERN LHC Equipment with RF fingers

    CERN Document Server

    Métral, E; Assmann, R W; Baglin, V; Barnes, M J; Berrig, O E; Bertarelli, A; Bregliozzi, G; Calatroni, S; Carra, F; Caspers, F; Day, H A; Ferro-Luzzi, M; Gallilee, M A; Garion, C; Garlasche, M; Grudiev, A; Jimenez, J M; Jones, R; Kononenko, O; Losito, R; Nougaret, J L; Parma, V; Redaelli, S; Salvant, B; Strubin, P; Veness, R; Vollinger, C; Weterings, W

    2013-01-01

    Beam-induced RF heating has been observed in several LHC components when the bunch/beam intensity was increased and/or the bunch length reduced. In particular eight bellows, out of the ten double-bellow modules present in the machine in 2011, were found with the spring, which should keep the RF fingers in good electrical contact with the central insert, broken. Following these observations, the designs of all the components of the LHC equipped with RF fingers have been reviewed. The lessons learnt and mitigation measures are presented in this paper.

  17. Comparative study of tool machinery sliding systems; comparison between plane and cylindrical basic shapes

    Science.gov (United States)

    Glăvan, D. O.; Babanatsas, T.; Babanatis Merce, R. M.; Glăvan, A.

    2018-01-01

    The paper brings in attention the importance that the sliding system of a tool machinery is having in the final precision of the manufacturing. We are basically comparing two type of slides, one constructed with plane surfaces and the other one with circular cross-sections (as known as cylindrical slides), analysing each solution from the point of view of its technology of manufacturing, of the precision that the particular slides are transferring to the tool machinery, cost of production, etc. Special attention is given to demonstrate theoretical and to confirm by experimental works what is happening with the stress distribution in the case of plane slides and cylindrical slides, both in longitudinal and in cross-over sections. Considering the results obtained for the stress distribution in the transversal and longitudinal cross sections, by composing them, we can obtain the stress distribution on the semicircular slide. Based on the results, special solutions for establishing the stress distribution between two surfaces without interact in the contact zone have been developed.

  18. Histopathology slide projector: a simple improvisation.

    Science.gov (United States)

    Agarwal, Akhilesh K R; Bhattacharya, Nirjhar

    2008-07-01

    The ability to examine histopathology and other hematological slides under microscope is a necessary and important service which should be available in every health facility. The slides need to be projected on to a screen. We describe an inexpensive and easily constructed technique for projecting magnified images of slides using a simple microscope. It is effective both for making observations and for use as a teaching aid.

  19. Radiosynoviorthesis in osteoarthritis of finger joints

    International Nuclear Information System (INIS)

    Moedder, G.

    2006-01-01

    This is an overview about osteoarthritis of the finger joints. The scientific publications according to the therapy of this disease by means of radiosynoviorthesis are presented, comparing the results in rheumatoid arthritis. Additionally own experience and results are reported. (orig.)

  20. Two-finger (TF) SPUDT cells.

    Science.gov (United States)

    Martin, Guenter; Biryukov, Sergey V; Schmidt, Hagen; Steiner, Bernd; Wall, Bert

    2011-03-01

    SPUDT cells including two fingers are only known thus far for so-called NSPUDT directions. In that case, usual solid-finger cells are used. The purpose of the present paper is to find SPUDT cell types consisting of two fingers only for pure mode directions. Two-finger (TF) cells for pure mode directions on substrates like 128°YX LiNbO(3) and YZ LiNbO(3) were found by means of an optimization procedure. The forward direction of a TF-cell SPUDT on 128°YX LiNbO(3) was determined experimentally. The properties of the new cells are compared with those of conventional SPUDT cells. The reflectivity of TF cells on 128°YX LiNbO(3) turns out to be two to three times larger than that of distributed acoustic reflection transducer (DART) and Hanma-Hunsinger cells at the same metal layer thickness.

  1. Finger prosthesis: a boon to handicapped.

    Science.gov (United States)

    Gupta, Ridhima; Kumar, Lakshya; Rao, Jitendra; Singh, Kamleshwar

    2013-08-29

    This is a clinical case report of a 52-year-old male patient with four partially missing fingers of the left hand. The article describes the clinical and laboratory procedure of making prosthesis with modern silicone material. A wax pattern was fabricated using the right hand of the patient. A special type of wax was formulated to make the pattern so that it can be easily moulded and carved. Intrinsic and extrinsic staining was also performed to match the adjacent skin colour. The patient was given the finger prosthesis and was asked to use a half glove (sports) to mask the junction between the prosthesis and the normal tissue. It also provides additional retention to the artificial fingers. The patient felt his social acceptance improved after wearing the finger prosthesis.

  2. Study of the tactile perception of bathroom tissues: Comparison between the sensory evaluation by a handfeel panel and a tribo-acoustic artificial finger.

    Science.gov (United States)

    Thieulin, C; Pailler-Mattei, C; Vargiolu, R; Lancelot, S; Zahouani, H

    2017-02-01

    Tactile perception is one of the sensorial modes most stimulated by our daily environment. In particular, perceived softness is an important parameter for judging the sensory quality of surfaces and fabrics. Unfortunately, its assessment greatly depends on the tactile sense of each person, which in turn depends on many factors. Currently, the predominant method for evaluating the tactile perception of fabrics is the human handfeel panel. This qualitative approach does not permit the quantitative measure of touch feel perception. In this study, we present a new artificial finger device to investigate the tactile sensing of ten bathroom tissues. It enables simultaneously measuring the friction and vibrations caused when sliding an artificial finger on the surface of the tissue. The comparison between the results obtained with the artificial finger and the tactile perception evaluated using a handfeel panel showed that the artificial finger is able to separate the two parts of the tactile perception of bathroom tissues: softness and surface texture (velvetiness). The statistical analysis suggests that there is a good correlation between the vibrations measured with the artificial finger and the softness evaluated by the panel. It then shows that the friction measured by the artificial finger is related to the surface texture of a bathroom tissue. The ability of the artificial finger to mimic human touch is demonstrated. Finally, a Principal Component Analysis orders the signatures of the tactile perception of the bathroom tissues in four different groups. Copyright © 2016. Published by Elsevier B.V.

  3. Self-adapted sliding scale spectroscopy ADC

    International Nuclear Information System (INIS)

    Xu Qichun; Wang Jingjin

    1992-01-01

    The traditional sliding scale technique causes a disabled range that is equal to the sliding length, thus reduces the analysis range of a MCA. A method for reduce ADC's DNL, which is called self-adapted sliding scale method, has been designed and tested. With this method, the disabled range caused by a traditional sliding scale method can be eliminated by a random trial scale and there is no need of an additional amplitude discriminator with swing threshold. A special trial-and-correct logic is presented. The tested DNL of the spectroscopy ADC described here is less than 0.5%

  4. Modelling the initiation of basal sliding

    Science.gov (United States)

    Mantelli, E.; Schoof, C.

    2017-12-01

    The initiation of basal sliding is a thermally-controlled process that affects ice speed, englacial heat transport, and melt water production at the bed, and ultimately influences the large-scale dynamics of ice sheets. From a modelling perspective, describing the onset of sliding in thin-film models suitable for ice sheet scale simulations is problematic. In particular, previous work concluded that, under shallow-ice mechanics, the scenario of a hard switch from frozen to molten bed leads to an infinite vertical velocity at the onset, and higher-order mechanical formulations are needed to describe sliding initiation. An alternative view considers the occurrence of subtemperate sliding, which allows for a smooth sliding velocity across the onset. However, the sliding velocity decreases rapidly as temperature drops below the melting point, thus raising the issue of whether a mechanical model that does not resolve the ice sheet thickness scale is ever appropriate to model the onset of sliding. In this study we first present a boundary layer model for the hard switch scenario. Our analysis, which considers a thermo-mechanically coupled Stokes flow near the onset, shows that the abrupt onset of sliding is never possible. In fact, the acceleration of ice flow deflects the flowlines towards the bed, which freezes again immediately downstream to the onset. This leads to the conclusion that the sliding velocity must change smoothly across the onset, thus the temperature dependence of sliding needs to be taken into account. In this context, we examine a limiting case of standard temperature-dependent sliding laws, where sliding onset takes the form of an extended transition region interposed between fully frozen and temperate bed. In the transition region basal temperature is at the melting point, and the sliding velocity varies smoothly as dictated by the energy budget of the bed. As the extent of this region is not small compared to the ice sheet length scale, we couple

  5. Stainless steel quadralatch finger test report

    International Nuclear Information System (INIS)

    Deichelbohrer, P.R.

    1996-01-01

    The design of the quadralatch on the universal samplers was changed in response to flammable gas operating constraints. Additional redesign of the fingers was included to facilitate manufacturability. The new design was tested to assure satisfactory performance. It was shown that the fingers can hold a sampler in place with an upward force of at least 2200 N (500 pounds) and that the mechanical remote latch unit can release the quadralatch under this condition of maximum upward force

  6. Development of a New RF Finger concept for vacuum beam line interconnections

    CERN Document Server

    Garion, C; Rambeau, H

    2012-01-01

    RF contact fingers are primarily used as a transition element to absorb the thermal expansion of vacuum chambers during bake-out and also to compensate for mechanical tolerances. They have to carry the beam image current to avoid the generation of Higher Order Modes and to reduce beam impedances. They are usually made out of copper beryllium thin sheets and are therefore very fragile and critical components. In this paper, a robust design based on a deformable finger concept is proposed. It allows the compensation of large longitudinal movements and also defaults such as transverse offset, twist or bending. The concept of this new RF fingers is first explained, then the design of the component is presented. The mechanical study based on a highly non-linear Finite Element model is shown as well as preliminary tests, including fatigue assessment, carried out on prototypes.

  7. Finger Search in the Implicit Model

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Nielsen, Jesper Asbjørn Sindahl; Truelsen, Jakob

    2012-01-01

    We address the problem of creating a dictionary with the finger search property in the strict implicit model, where no information is stored between operations, except the array of elements. We show that for any implicit dictionary supporting finger searches in q(t) = Ω(logt) time, the time to move...... the finger to another element is Ω(q− 1(logn)), where t is the rank distance between the query element and the finger. We present an optimal implicit static structure matching this lower bound. We furthermore present a near optimal implicit dynamic structure supporting search, change-finger, insert......, and delete in times $\\mathcal{O}(q(t))$, $\\mathcal{O}(q^{-1}(\\log n)\\log n)$, $\\mathcal{O}(\\log n)$, and $\\mathcal{O}(\\log n)$, respectively, for any q(t) = Ω(logt). Finally we show that the search operation must take Ω(logn) time for the special case where the finger is always changed to the element...

  8. Finger replantation: surgical technique and indications.

    Science.gov (United States)

    Barbary, S; Dap, F; Dautel, G

    2013-12-01

    In this article, we discuss the surgical technique of finger replantation in detail, distinguishing particularities of technique in cases of thumb amputation, children fingertip replantation, ring finger avulsion, and very distal replantations. We emphasize the principles of bone shortening, the spare part concept, the special importance of nerve sutures and the use of vein graft in case of avulsion or crushing. However, even if finger replantation is now a routine procedure, a clear distinction should be made between revascularization and functional success. The indications for finger replantation are then detailed in the second part of this paper. The absolute indications for replantation are thumb, multiple fingers, transmetacarpal or hand, and any upper extremity amputation in a child whatever the level. Fingertip amputations distal to the insertion of the Flexor digitorum superficialis (FDS) are also a good indication. Other cases are more controversial because of the poor functional outcome, especially for the index finger, which is often functionally excluded. Copyright © 2013. Published by Elsevier SAS.

  9. New Finger Biometric Method Using Near Infrared Imaging

    Science.gov (United States)

    Lee, Eui Chul; Jung, Hyunwoo; Kim, Daeyeoul

    2011-01-01

    In this paper, we propose a new finger biometric method. Infrared finger images are first captured, and then feature extraction is performed using a modified Gaussian high-pass filter through binarization, local binary pattern (LBP), and local derivative pattern (LDP) methods. Infrared finger images include the multimodal features of finger veins and finger geometries. Instead of extracting each feature using different methods, the modified Gaussian high-pass filter is fully convolved. Therefore, the extracted binary patterns of finger images include the multimodal features of veins and finger geometries. Experimental results show that the proposed method has an error rate of 0.13%. PMID:22163741

  10. Finger multibiometric cryptosystems: fusion strategy and template security

    Science.gov (United States)

    Peng, Jialiang; Li, Qiong; Abd El-Latif, Ahmed A.; Niu, Xiamu

    2014-03-01

    We address two critical issues in the design of a finger multibiometric system, i.e., fusion strategy and template security. First, three fusion strategies (feature-level, score-level, and decision-level fusions) with the corresponding template protection technique are proposed as the finger multibiometric cryptosystems to protect multiple finger biometric templates of fingerprint, finger vein, finger knuckle print, and finger shape modalities. Second, we theoretically analyze different fusion strategies for finger multibiometric cryptosystems with respect to their impact on security and recognition accuracy. Finally, the performance of finger multibiometric cryptosystems at different fusion levels is investigated on a merged finger multimodal biometric database. The comparative results suggest that the proposed finger multibiometric cryptosystem at feature-level fusion outperforms other approaches in terms of verification performance and template security.

  11. Eurosafe-2011 - Papers and slides

    International Nuclear Information System (INIS)

    2012-01-01

    This document gathers some slides, papers and posters that were presented at the 2011 annual EUROSAFE forum. This forum focuses in its plenary part on 'Nuclear safety: new challenges, gained experience and public expectations' in the light of the Fukushima nuclear power station (NPS) accident. The topic will be considered from the point of view of Japanese safety authorities, of a regulator, of an international organisation, of a utility and of a Technical Safety Organisation (TSO). The first part of the second day will be devoted to presentations of the Fukushima NPS accident. The second part of this day will present the latest work carried out by ETSON (European Technical Safety Organizations Network) and EUROSAFE members and their partners worldwide through three seminars (nuclear safety research and safety assessment, radiation protection and environment, nuclear material and nuclear facilities security) and a workshop on operating experience feedback on nuclear fuel cycle facilities

  12. Sliding friction at poly(vinyl alcohol)-modified carbon nanotube interfaces

    Science.gov (United States)

    Zhang, Xiaohua

    2018-01-01

    The sliding friction between adjacent carbon nanotubes (CNTs) determines greatly the mechanical property of CNT assembly materials. In order to enhance the intertube friction, polymer molecules are often introduced between CNTs. This paper reveals a new energy dissipation mechanism for the deformed CNT contacts by poly(vinyl alcohol) (PVA). When PVA is introduced into a CNT bundle, most segments of the polymer chain lay on the grooves of adjacent CNTs, while several short segments span over the contact CNTs by inducing a structural deformation on the tubular structure. During the tube sliding, the deformation is recovered and a new one is formed at the next position, contributing to new energy dissipation to prevent the tube sliding. As a result, the friction force can be enhanced by up to eight-fold. This study indicates that a network of transverse polymer chains and longitudinal CNTs is important towards high mechanical properties.

  13. Rehabilitation of single finger amputation with customized silicone prosthesis

    OpenAIRE

    Yadav, Niharika; Chand, Pooran; Jurel, Sunit Kumar

    2016-01-01

    Finger amputations are common in accidents at home, work, and play. Apart from trauma, congenital disease and deformity also leads to finger amputation. This results in loss of function, loss of sensation as well as loss of body image. Finger prosthesis offers psychological support and social acceptance in such cases. This clinical report describes a method to fabricate ring retained silicone finger prosthesis in a patient with partial finger loss.

  14. Finger tapping ability in healthy elderly and young adults.

    Science.gov (United States)

    Aoki, Tomoko; Fukuoka, Yoshiyuki

    2010-03-01

    The maximum isometric force production capacity of the fingers decreases with age. However, little information is available on age-related changes in dynamic motor capacity of individual fingers. The purpose of this study was to compare the dynamic motor function of individual fingers between elderly and young adults using rapid single-finger and double-finger tapping. Fourteen elderly and 14 young adults performed maximum frequency tapping by the index, middle, ring, or little finger (single-finger tapping) and with alternate movements of the index-middle, middle-ring, or ring-little finger-pair (double-finger tapping). The maximum pinch force between the thumb and each finger, tactile sensitivity of each fingertip, and time taken to complete a pegboard test were also measured. Compared with young subjects, the older subjects had significantly slower tapping rates in all fingers and finger-pairs in the tapping tasks. The age-related decline was also observed in the tactile sensitivities of all fingers and in the pegboard test. However, there was no group difference in the pinch force of any finger. The tapping rate of each finger did not correlate with the pinch force or tactile sensitivity for the corresponding finger in the elderly subjects. Maximum rate of finger tapping was lower in the elderly adults compared with the young adults. The decline of finger tapping ability in elderly adults seems to be less affected by their maximum force production capacities of the fingers as well as tactile sensitivities at the tips of the fingers.

  15. The artificial zinc finger coding gene 'Jazz' binds the utrophin promoter and activates transcription.

    Science.gov (United States)

    Corbi, N; Libri, V; Fanciulli, M; Tinsley, J M; Davies, K E; Passananti, C

    2000-06-01

    Up-regulation of utrophin gene expression is recognized as a plausible therapeutic approach in the treatment of Duchenne muscular dystrophy (DMD). We have designed and engineered new zinc finger-based transcription factors capable of binding and activating transcription from the promoter of the dystrophin-related gene, utrophin. Using the recognition 'code' that proposes specific rules between zinc finger primary structure and potential DNA binding sites, we engineered a new gene named 'Jazz' that encodes for a three-zinc finger peptide. Jazz belongs to the Cys2-His2 zinc finger type and was engineered to target the nine base pair DNA sequence: 5'-GCT-GCT-GCG-3', present in the promoter region of both the human and mouse utrophin gene. The entire zinc finger alpha-helix region, containing the amino acid positions that are crucial for DNA binding, was specifically chosen on the basis of the contacts more frequently represented in the available list of the 'code'. Here we demonstrate that Jazz protein binds specifically to the double-stranded DNA target, with a dissociation constant of about 32 nM. Band shift and super-shift experiments confirmed the high affinity and specificity of Jazz protein for its DNA target. Moreover, we show that chimeric proteins, named Gal4-Jazz and Sp1-Jazz, are able to drive the transcription of a test gene from the human utrophin promoter.

  16. Dry sliding wear behavior of heat treated hybrid metal matrix composite using Taguchi techniques

    International Nuclear Information System (INIS)

    Kiran, T.S.; Prasanna Kumar, M.; Basavarajappa, S.; Viswanatha, B.M.

    2014-01-01

    Highlights: • ZA-27 alloy is used as matrix material and reinforced with SiC and Gr particles. • Heat treatment was carried out for all specimen. • Dry sliding wear test was done on pin-on-disc apparatus by Taguchi technique. • ZA-27/9SiC–3Gr showed superior wear resistance over the base alloy. • Ceramic mixed mechanical layer on contact surface of composite was formed. - Abstract: Dry sliding wear behavior of zinc based alloy and composite reinforced with SiCp (9 wt%) and Gr (3 wt%) fabricated by stir casting method was investigated. Heat treatment (HT) and aging of the specimen were carried out, followed by water quenching. Wear behavior was evaluated using pin on disc apparatus. Taguchi technique was used to estimate the parameters affecting the wear significantly. The effect of HT was that it reduced the microcracks, residual stresses and improved the distribution of microconstituents. The influence of various parameters like applied load, sliding speed and sliding distance on wear behavior was investigated by means and analysis of variance (ANOVA). Further, correlation between the parameters was determined by multiple linear regression equation for each response. It was observed that the applied load significantly influenced the wear volume loss (WVL), followed by sliding speed implying that increase in either applied load or sliding speed increases the WVL. Whereas for composites, sliding distance showed a negative influence on wear indicating that increase in sliding distance reduces WVL due to the presence of reinforcements. The wear mechanism of the worn out specimen was analyzed using scanning electron microscopy. The analysis shows that the formation and retention of ceramic mixed mechanical layer (CMML) plays a major role in the dry sliding wear resistance

  17. Graphene as a protective coating and superior lubricant for electrical contacts

    Science.gov (United States)

    Berman, Diana; Erdemir, Ali; Sumant, Anirudha V.

    2014-12-01

    Potential for graphene to be used as a lubricant for sliding electrical contacts has been evaluated. Graphene, being deposited as a sporadic flakes on the gold substrate sliding against titanium nitride ball shows not only significant improvement in tribological behavior by reducing both friction (by factor of 2-3) and wear (by 2 orders) but also, even more importantly, demonstrates stable and low electrical resistance at the sliding contacts undergoing thousands of sliding passes regardless of the test environment (i.e., both in humid and dry conditions).

  18. Modeling the Sliding/Falling Ladder Paradox

    Science.gov (United States)

    Fox, William P.; Fox, James B.

    2003-01-01

    Recently we were presented with an interesting twist to the sliding ladder problem viewed in the related rates section of most calculus textbooks. Our problem concerning a sliding ladder that eventually hits the ground. At first, those attempting this problem fell into the calculus trap using only related rates. Previous work for this problem…

  19. [Heritage Education Lesson Plans and Slide Presentations].

    Science.gov (United States)

    Van Buren, Maurie

    Field tested in 27 schools and in grades four through twelve, this teaching unit stresses heritage education through the study of southern U.S. architectural styles for homes from the pioneer log structures to the 1950s ranch home. Each of the four lessons in this unit focuses around a slide presentation of 20 slides designed to fit into one…

  20. In situ observation of a hydrogel-glass interface during sliding friction

    OpenAIRE

    Yamamoto, Tetsurou; Kurokawa, Takayuki; Ahmed, Jamil; Kamita, Gen; Yashima, Shintaro; Furukawa, Yuichiro; Ota, Yuko; Furukawa, Hidemitsu; Gong, Jian Ping

    2014-01-01

    Direct observation of hydrogel contact with a solid surface in water is indispensable for understanding the friction, lubrication, and adhesion of hydrogels under water. However, this is a difficult task since the refractive index of hydrogels is very close to that of water. In this paper, we present a novel method to in situ observe the macroscopic contact of hydrogels with a solid surface based on the principle of critical refraction. This method was applied to investigate the sliding frict...

  1. On the sliding friction at the interface between a fluid and a solid

    International Nuclear Information System (INIS)

    Minetti-Mezzetti, E.

    1976-01-01

    A method is reported to investigate the possible existence and the numerical value of the sliding friction coefficient β at the contact interface between a fluid and a solid. Some preliminary experimental results at the interface glycerol-aluminium give 1/β -4 . (author)

  2. Stick-slip behaviour of a viscoelastic flat sliding along a rigid indenter

    NARCIS (Netherlands)

    Budi Setiyana, Budi; Ismail, Rifky; Jamari, J.; Schipper, Dirk Jan

    2016-01-01

    The sliding contact of soft material surface due to a rigid indenter is different from metal and some other polymers. A stick-slip motion is more frequently obtained than a smooth motion. By modeling the soft material as low damping viscoelastic material, this study proposes an analytical model to

  3. Design and preliminary evaluation of the FINGER rehabilitation robot: controlling challenge and quantifying finger individuation during musical computer game play.

    Science.gov (United States)

    Taheri, Hossein; Rowe, Justin B; Gardner, David; Chan, Vicki; Gray, Kyle; Bower, Curtis; Reinkensmeyer, David J; Wolbrecht, Eric T

    2014-02-04

    This paper describes the design and preliminary testing of FINGER (Finger Individuating Grasp Exercise Robot), a device for assisting in finger rehabilitation after neurologic injury. We developed FINGER to assist stroke patients in moving their fingers individually in a naturalistic curling motion while playing a game similar to Guitar Hero. The goal was to make FINGER capable of assisting with motions where precise timing is important. FINGER consists of a pair of stacked single degree-of-freedom 8-bar mechanisms, one for the index and one for the middle finger. Each 8-bar mechanism was designed to control the angle and position of the proximal phalanx and the position of the middle phalanx. Target positions for the mechanism optimization were determined from trajectory data collected from 7 healthy subjects using color-based motion capture. The resulting robotic device was built to accommodate multiple finger sizes and finger-to-finger widths. For initial evaluation, we asked individuals with a stroke (n = 16) and without impairment (n = 4) to play a game similar to Guitar Hero while connected to FINGER. Precision design, low friction bearings, and separate high speed linear actuators allowed FINGER to individually actuate the fingers with a high bandwidth of control (-3 dB at approximately 8 Hz). During the tests, we were able to modulate the subject's success rate at the game by automatically adjusting the controller gains of FINGER. We also used FINGER to measure subjects' effort and finger individuation while playing the game. Test results demonstrate the ability of FINGER to motivate subjects with an engaging game environment that challenges individuated control of the fingers, automatically control assistance levels, and quantify finger individuation after stroke.

  4. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger-arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3-DOF fingers are attached to the end-effector of a 6-DOF arm to configure a multi-finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi-finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini-max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi-finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  5. Quantifying Parkinson's disease finger-tapping severity by extracting and synthesizing finger motion properties.

    Science.gov (United States)

    Sano, Yuko; Kandori, Akihiko; Shima, Keisuke; Yamaguchi, Yuki; Tsuji, Toshio; Noda, Masafumi; Higashikawa, Fumiko; Yokoe, Masaru; Sakoda, Saburo

    2016-06-01

    We propose a novel index of Parkinson's disease (PD) finger-tapping severity, called "PDFTsi," for quantifying the severity of symptoms related to the finger tapping of PD patients with high accuracy. To validate the efficacy of PDFTsi, the finger-tapping movements of normal controls and PD patients were measured by using magnetic sensors, and 21 characteristics were extracted from the finger-tapping waveforms. To distinguish motor deterioration due to PD from that due to aging, the aging effect on finger tapping was removed from these characteristics. Principal component analysis (PCA) was applied to the age-normalized characteristics, and principal components that represented the motion properties of finger tapping were calculated. Multiple linear regression (MLR) with stepwise variable selection was applied to the principal components, and PDFTsi was calculated. The calculated PDFTsi indicates that PDFTsi has a high estimation ability, namely a mean square error of 0.45. The estimation ability of PDFTsi is higher than that of the alternative method, MLR with stepwise regression selection without PCA, namely a mean square error of 1.30. This result suggests that PDFTsi can quantify PD finger-tapping severity accurately. Furthermore, the result of interpreting a model for calculating PDFTsi indicated that motion wideness and rhythm disorder are important for estimating PD finger-tapping severity.

  6. Robotic finger perturbation training improves finger postural steadiness and hand dexterity.

    Science.gov (United States)

    Yoshitake, Yasuhide; Ikeda, Atsutoshi; Shinohara, Minoru

    2018-02-01

    The purpose of the study was to understand the effect of robotic finger perturbation training on steadiness in finger posture and hand dexterity in healthy young adults. A mobile robotic finger training system was designed to have the functions of high-speed mechanical response, two degrees of freedom, and adjustable loading amplitude and direction. Healthy young adults were assigned to one of the three groups: random perturbation training (RPT), constant force training (CFT), and control. Subjects in RPT and CFT performed steady posture training with their index finger using the robot in different modes: random force in RPT and constant force in CFT. After the 2-week intervention period, fluctuations of the index finger posture decreased only in RPT during steady position-matching tasks with an inertial load. Purdue pegboard test score improved also in RPT only. The relative change in finger postural fluctuations was negatively correlated with the relative change in the number of completed pegs in the pegboard test in RPT. The results indicate that finger posture training with random mechanical perturbations of varying amplitudes and directions of force is effective in improving finger postural steadiness and hand dexterity in healthy young adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Grid lattice with sliding strap

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1977-01-01

    The invention provides means for inserting tubular members into a grid structure without mutual contact between the tubular members. After the tubular members are inserted, a movable strap is slid into position, thereby engaging, locating, and supporting the tubular member in a fixed location. (Auth.)

  8. Viscoelastic fingering with a pulsed pressure signal

    International Nuclear Information System (INIS)

    Corvera Poire, E; Rio, J A del

    2004-01-01

    We derive a generalized Darcy's law in the frequency domain for a linear viscoelastic fluid flowing in a Hele-Shaw cell. This leads to an analytic expression for the dynamic permeability that has maxima which are several orders of magnitude larger than the static permeability. We then follow an argument of de Gennes (1987 Europhys. Lett. 2 195) to obtain the smallest possible finger width when viscoelasticity is important. Using this and a conservation law, we obtain the lowest bound for the width of a single finger displacing a viscoelastic fluid. When the driving force consists of a constant pressure gradient plus an oscillatory signal, our results indicate that the finger width varies in time following the frequency of the incident signal. Also, the amplitude of the finger width in time depends on the value of the dynamic permeability at the imposed frequency. When the finger is driven with a frequency that maximizes the permeability, variations in the amplitude are also maximized. This gives results that are very different for Newtonian and viscoelastic fluids. For the former ones the amplitude of the oscillation decays with frequency. For the latter ones on the other hand, the amplitude has maxima at the same frequencies that maximize the dynamic permeability

  9. Saffman-Taylor fingers with kinetic undercooling

    KAUST Repository

    Gardiner, Bennett P. J.

    2015-02-23

    © 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

  10. Saffman-Taylor fingers with kinetic undercooling

    KAUST Repository

    Gardiner, Bennett P. J.; McCue, Scott W.; Dallaston, Michael C.; Moroney, Timothy J.

    2015-01-01

    © 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

  11. Slides with no attached paper

    International Nuclear Information System (INIS)

    Warin, Dominique; Wallenius, Janne; Ouzounian, Gerald; Wikberg, Peter; Todd, Terry A.; Kormilitsyn, Mikhael V.; Osipenko, Alexander G.; Mayorshin, A.A.; McLachlan, Fiona; Nash, Ken L.; Nilsson, M.; Grimes, T.; Braley, J.C.; TAKESHITA, Kenji; Babain, Vasiliy A.; Spendlikova, I.; Distler, P.; John, J.; Sebesta, F.; VU, Trong-Hung; SIMONIN, Jean-Pierre; PAULENOVA, Alena; PRECEK, Martin; HARTIG, Kyle; KNAPP, Nathan; Vidick, Geoffrey; Bouslimani, Nouri; Desreux, Jean F.; Lewis, F.W.; Hudson, M.J.; Harwood, L.M.; Nunez, Ana; Nagarajan, K.; Vasudeva Rao, P.R.; Raj, Baldev; Ignatiev, Victor; Surenkov, Alexander; Pouchon, Manuel A.; Skarnemark, Gunnar; Allard, Stefan; Ekberg, Christian; Retegan, Teodora; Nordlund, Anders; John, Jan; Maershin, Alexander; Zakirov, R.; Panov, A.; Toropov, Andrey

    2010-01-01

    This document brings together the different presentations (slides) given at the workshop but with no attached paper. These slides refer to the following presentations: - Presentation of ITN (Instituto Tecnologico e Nuclear); - Minor Actinide Partitioning (Dominique Warin); - Transmutation (Janne Wallenius); - Radioactive Waste Management, IGD-TP (Gerald Ouzounian); - Present status of the Swedish nuclear waste management programme (Peter Wikberg); - The U.S. Fuel Cycle Research and Development Program - Separations Research and Development (Terry Todd); - Strategies and national programs of closed fuel cycles - Russian Expert Vision (Mikhael Kormilitsyn) - Extraction Studies Of Potential Solvent Formulations For The GANEX Process (Fiona MacLachlan); - Investigations of The Fundamental Chemistry of the TALSPEAK Process (Ken Nash); - Extraction Separation of Trivalent Minor Actinides and Lanthanides by Hexa-dentate Nitrogen-donor Extractant, TPEN, and its Analogs (Kenji Takeshita); - Fluorinated Diluents for HLW Processing - technological point of view (Vasiliy Babain); - Extraction properties of some new pyridine molecules and search for better diluents (Irena Spendlikova); - Kinetics of extraction of Eu 3+ ion by TODGA and CyMe 4 -BTBP studied using the RMC technique (Trong Hung Vu); - Redox Chemistry of Neptunium in Solutions of Nitric Acid (Alena Paulenova); - NMR applied to actinide ions and their complexes. In search of covalency effects (Geoffrey Vidick); - Towards 'Stability Rules' for Radiolysis of bis-DGA compounds (Ana Nunez); - Pyroprocess Research Activities at IGCAR, Kalpakkam, India (K. Nagarajan); - Critical issues of nuclear energy systems employing molten salt fluorides: from ISTC No. 1606 to No. 3749 (1. year of project activity) and MARS/EVOL cooperation (Victor Ignatiev); - Conversion processes: Internal Gelation and the Sphere-pac concept (Manuel Pouchon); - A Combined Nuclear Technology and Nuclear Chemistry Master. A Unique

  12. Contact stress analysis of involute spur gear by Finite Element ...

    African Journals Online (AJOL)

    In this paper the contact stress in rolling-sliding contact of involute spur gear and the effect of coefficient of friction was analyzed. To achieve this, first, three dimensional involute spur gear pairs were developed in Solid works 2012 Premium and the 3D model was exported to ANSYS workbench 14.5. Next, the analysis was ...

  13. Perceiving fingers in single-digit arithmetic problems

    Directory of Open Access Journals (Sweden)

    Ilaria eBerteletti

    2015-03-01

    Full Text Available In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense.

  14. Perceiving fingers in single-digit arithmetic problems.

    Science.gov (United States)

    Berteletti, Ilaria; Booth, James R

    2015-01-01

    In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense.

  15. Thresholds in the sliding resistance of simulated basal ice

    Directory of Open Access Journals (Sweden)

    L. F. Emerson

    2007-10-01

    Full Text Available We report laboratory determinations of the shear resistance to sliding melting ice with entrained particles over a hard, impermeable surface. With higher particle concentrations and larger particle sizes, Coulomb friction at particle-bed contacts dominates and the shear stress increases linearly with normal load. We term this the sandy regime. When either particle concentration or particle size is reduced below a threshold, the dependence of shear resistance on normal load is no longer statistically significant. We term this regime slippery. We use force and mass balance considerations to examine the flow of melt water beneath the simulated basal ice. At high particle concentrations, the transition from sandy to slippery behavior occurs when the particle size is comparable to the thickness of the melt film that separates the sliding ice from its bed. For larger particle sizes, a transition from sandy to slippery behavior occurs when the particle concentration drops sufficiently that the normal load is no longer transferred completely to the particle-bed contacts. We estimate that the melt films separating the particles from the ice are approximately 0.1 µm thick at this transition. Our laboratory results suggest the potential for abrupt transitions in the shear resistance beneath hard-bedded glaciers with changes in either the thickness of melt layers or the particle loading.

  16. Prosthetic finger phalanges with lifelike skin compliance for low-force social touching interactions

    Directory of Open Access Journals (Sweden)

    Ge Shuzhi

    2011-03-01

    Full Text Available Abstract Background Prosthetic arms and hands that can be controlled by the user's electromyography (EMG signals are emerging. Eventually, these advanced prosthetic devices will be expected to touch and be touched by other people. As realistic as they may look, the currently available prosthetic hands have physical properties that are still far from the characteristics of human skins because they are much stiffer. In this paper, different configurations of synthetic finger phalanges have been investigated for their skin compliance behaviour and have been compared with the phalanges of the human fingers and a phalanx from a commercially available prosthetic hand. Methods Handshake tests were performed to identify which areas on the human hand experience high contact forces. After these areas were determined, experiments were done on selected areas using an indenting probe to obtain the force-displacement curves. Finite element simulations were used to compare the force-displacement results of the synthetic finger phalanx designs with that of the experimental results from the human and prosthetic finger phalanges. The simulation models were used to investigate the effects of (a varying the internal topology of the finger phalanx and (b varying different materials for the internal and external layers. Results and Conclusions During handshake, the high magnitudes of contact forces were observed at the areas where the full grasping enclosure of the other person's hand can be achieved. From these areas, the middle phalanges of the (a little, (b ring, and (c middle fingers were selected. The indentation experiments on these areas showed that a 2 N force corresponds to skin tissue displacements of more than 2 mm. The results from the simulation model show that introducing an open pocket with 2 mm height on the internal structure of synthetic finger phalanges increased the skin compliance of the silicone material to 235% and the polyurethane material to

  17. Whole slide imaging for educational purposes

    Directory of Open Access Journals (Sweden)

    Liron Pantanowitz

    2012-01-01

    Full Text Available Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy. Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI. As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools, training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology, for virtual tracking and tutoring, tele-education (tele-conferencing, e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed.

  18. An updated nuclear criticality slide rule

    International Nuclear Information System (INIS)

    Hopper, C.M.; Broadhead, B.L.

    1998-04-01

    This Volume 2 contains the functional version of the updated nuclear criticality slide rule (more accurately, sliding graphs) that is referenced in An Updated Nuclear Criticality Slide Rule: Technical Basis, NUREG/CR-6504, Vol. 1 (ORNL/TM-13322/V1). This functional slide rule provides a readily usable open-quotes in-handclose quotes method for estimating pertinent nuclear criticality accident information from sliding graphs, thereby permitting (1) the rapid estimation of pertinent criticality accident information without laborious or sophisticated calculations in a nuclear criticality emergency situation, (2) the appraisal of potential fission yields and external personnel radiation exposures for facility safety analyses, and (3) a technical basis for emergency preparedness and training programs at nonreactor nuclear facilities. The slide rule permits the estimation of neutron and gamma dose rates and integrated doses based upon estimated fission yields, distance from the fission source, and time-after criticality accidents for five different critical systems. Another sliding graph permits the estimation of critical solution fission yields based upon fissile material concentration, critical vessel geometry, and solution addition rate. Another graph provides neutron and gamma dose-reduction factors for water, steel, and concrete. Graphs from historic documents are provided as references for estimating critical parameters of various fissile material systems. Conversion factors for various English and metric units are provided for quick reference

  19. Finger millet [Eleusine coracana (L.) Gaertn].

    Science.gov (United States)

    Ceasar, Stanislaus Antony; Ignacimuthu, Savarimuthu

    2015-01-01

    Millets are the primary food source for millions of people in tropical regions of the world supplying mineral nutrition and protein. In this chapter, we describe an optimized protocol for the Agrobacterium-mediated transformation of finger millet variety GPU 45. Agrobacterium strain LBA4404 harboring plasmid pCAMBIA1301 which contains hygromycin phosphotransferase (hph) as selectable marker gene and β-glucuronidase (GUS) as reporter gene has been used. This protocol utilizes the shoot apex explants for the somatic embryogenesis and regeneration of finger millet after the transformation by Agrobacterium. Desiccation of explants during cocultivation helps for the better recovery of transgenic plants. This protocol is very useful for the efficient production of transgenic plants in finger millet through Agrobacterium-mediated transformation.

  20. Automatic analysis of force distribution in multi-fingered articulated hands

    Science.gov (United States)

    Amani, Mahyar

    A kinematic and force analysis of multifingered, multijointed dexterous hands is presented. The analysis involves calculation of the basis for null space of the grasp matrix. An algorithm is developed to perform all necessary analyses of dexterous hands. All equality and inequality constraints are automatically formulated in a constraint matrix. These include unisense constraints, frictional constraints, and joint torque limits. The reduction of the constraint matrix into a compact form is also presented. The algorithm is written in Fortran and is user-friendly and capable of handling all practical grasping problems. Different types of contact may be examined, including soft finger contact and point contact with and without friction. The software can easily determine the feasibility of a grasp for a given set of contact forces/torques, and may potentially be combined with either routines to compute the optimum value of contact wrench intensities and joint torque values.

  1. Ergometer rowing with and without slides

    DEFF Research Database (Denmark)

    Larsen, Anders Holsgaard; Jensen, K

    2010-01-01

    A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars......-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke...

  2. Contamination by human fingers. The Midas touch

    International Nuclear Information System (INIS)

    Gwozdz, R.; Grass, F.

    2004-01-01

    Anthropogenic activity is one of the causes of contamination in the human environment: contamination of air, water, top soils, plants and food products has complex effects on human health problems. Wear and abrasion of various surfaces are constant processes in daily life, and commonly include interaction between human fingers and surfaces of every conceivable material. New methods for investigation of trace transfer processes by human fingers are described. Results of transfer for commonly used metals such as gold, silver, zinc, cadmium, tin, cobalt, nickel, chromium and iron are presented. Relationship between transfer of metals by touch and the general problem of purity in analytical activities is briefly discussed. (author)

  3. Fluctuation of biological rhythm in finger tapping

    Science.gov (United States)

    Yoshinaga, H.; Miyazima, S.; Mitake, S.

    2000-06-01

    By analyzing biological rhythms obtained from finger tapping, we have investigated the differences of two biological rhythms between healthy and handicapped persons caused by Parkinson, brain infraction, car accident and so on. In this study, we have observed the motion of handedness of all subjects and obtained a slope a which characterizes a power-law relation between frequency and amplitude of finger-tapping rhythm. From our results, we have estimated that the slope a=0.06 is a rough criterion in order to distinguish healthy and handicapped persons.

  4. FingerSynth: Wearable Transducers for Exploring the Environment and Playing Music Everywhere

    OpenAIRE

    Dublon, Gershon; Paradiso, Joseph A.

    2014-01-01

    We present the FingerSynth, a wearable musical instrument made up of a bracelet and set of rings that enable its player to produce sound by touching nearly any surface in their environment. Each ring contains a small, independently controlled exciter transducer commonly used for auditory bone conduction. The rings sound loudly when they touch a hard object, and are practically silent otherwise. When a wearer touches their own (or someone else's) head, the contacted person hears the sound thro...

  5. A thermodynamic model of contact angle hysteresis.

    Science.gov (United States)

    Makkonen, Lasse

    2017-08-14

    When a three-phase contact line moves along a solid surface, the contact angle no longer corresponds to the static equilibrium angle but is larger when the liquid is advancing and smaller when the liquid is receding. The difference between the advancing and receding contact angles, i.e., the contact angle hysteresis, is of paramount importance in wetting and capillarity. For example, it determines the magnitude of the external force that is required to make a drop slide on a solid surface. Until now, fundamental origin of the contact angle hysteresis has been controversial. Here, this origin is revealed and a quantitative theory is derived. The theory is corroborated by the available experimental data for a large number of solid-liquid combinations. The theory is applied in modelling the contact angle hysteresis on a textured surface, and these results are also in quantitative agreement with the experimental data.

  6. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Takayuki Hori

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger‐arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3‐DOF fingers are attached to the end‐effector of a 6‐DOF arm to configure a multi‐finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi‐finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini‐max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi‐finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  7. SlideToolkit: an assistive toolset for the histological quantification of whole slide images.

    Directory of Open Access Journals (Sweden)

    Bastiaan G L Nelissen

    Full Text Available The demand for accurate and reproducible phenotyping of a disease trait increases with the rising number of biobanks and genome wide association studies. Detailed analysis of histology is a powerful way of phenotyping human tissues. Nonetheless, purely visual assessment of histological slides is time-consuming and liable to sampling variation and optical illusions and thereby observer variation, and external validation may be cumbersome. Therefore, within our own biobank, computerized quantification of digitized histological slides is often preferred as a more precise and reproducible, and sometimes more sensitive approach. Relatively few free toolkits are, however, available for fully digitized microscopic slides, usually known as whole slides images. In order to comply with this need, we developed the slideToolkit as a fast method to handle large quantities of low contrast whole slides images using advanced cell detecting algorithms. The slideToolkit has been developed for modern personal computers and high-performance clusters (HPCs and is available as an open-source project on github.com. We here illustrate the power of slideToolkit by a repeated measurement of 303 digital slides containing CD3 stained (DAB abdominal aortic aneurysm tissue from a tissue biobank. Our workflow consists of four consecutive steps. In the first step (acquisition, whole slide images are collected and converted to TIFF files. In the second step (preparation, files are organized. The third step (tiles, creates multiple manageable tiles to count. In the fourth step (analysis, tissue is analyzed and results are stored in a data set. Using this method, two consecutive measurements of 303 slides showed an intraclass correlation of 0.99. In conclusion, slideToolkit provides a free, powerful and versatile collection of tools for automated feature analysis of whole slide images to create reproducible and meaningful phenotypic data sets.

  8. ANALYSIS of Control Force Grasping for a Multifunctional Five Fingered Robot to Pick-up Various of Components

    Directory of Open Access Journals (Sweden)

    Widhiada W.

    2016-01-01

    Full Text Available Multi-fingered robot gripper has become popular in the major research topics as grasping an object in robotic systems. The author considers a matter of style-based control model for a multi-fingered robot hand grasping an object with a known geometric characteristics. This paper introduces design process and analysis of contact force the five fingered gripper suitable to handle several of objects. The author applied Simulink/SimMechanics, Support package Arduino and Inventor software packages to facilatate and integrated the design of contact force gripper systems. The advance of PID control is used to control dynamics motions of the five fingered gripper systems. The multifunction finger’s gripper is developed to handle the various components. Contact force between fingertips and object surface is computed using the Hooke law concept. The analysis of experiment result shows the optimum of contact forces are achieved to hold the object. The spring and damper algorithm is used to compute the interaction of force between fingertips and object surface.

  9. [Treatment of trigger finger with located needle knife].

    Science.gov (United States)

    Zhang, Qi-Feng; Yang, Jiang; Xi, Sheng-Hua

    2016-07-25

    To investigate the clinical effects of located needle knife in the treatment of trigger finger. The clinical data of 133 patients(145 fingers) with trigger finger underwent treatment with located needle knife from September 2010 to March 2014 were retrospectively analyzed. There were 37 males(40 fingers) and 96 females (105 fingers), aged from 18 to 71 years old with a mean of 51.8 years. Course of disease was from 1 to 19 months with an average of 8.2 months. Affected fingers included 82 thumbs, 12 index fingers, 11 middle fingers, 36 ring fingers, and 4 little fingers. According to the standard of Quinnell grade, 42 fingers were grade III, 92 fingers were grade IV, and 11 fingers were grade V. Firstly the double pipe gab was put into the distal edge of hypertrophic tendon sheath, then small knife needle was used to release the sheath proximally along the tendon line direction. The informations of wound healing and nerve injury, postoperative finger function, finger pain at 6 months were observed. The operation time was from 8 to 25 min with an average of 9.8 min. All the patients were followed up from 6 to 26 months with an average of 12.5 months. No complications such as the wound inflammation and seepage, vascular or nerve injuries were found. According to the standard of Quinnell grade, 123 fingers got excellent results, 15 good, 7 poor. It's a good choice to treat trigger finger with located needle knife in advantage of minimal invasion, simple safe operation, and it should be promoted in clinic.

  10. ANALYSIS WITH MSC ADAMS OF A 5-FINGER AND 3-PHALANX /FINGER UNDER-ACTUATEDMECHANICAL HAND

    Directory of Open Access Journals (Sweden)

    Gheorghe POPESCU

    2013-05-01

    Full Text Available This paper studies the analysis with MSC ADAMS of a 5-fingered and 3-phalanx/finger underactuatedmechanical hand, designed by the author to work on industrial robots. Moreover, in order to increasegrasping safety in the automated handling process, the author has fitted each finger with a locking sequence inthe final phase of grasping. Thus, the mechanism of mechanical hand is considered to be a mechanical systemand is treated like a set of rigid bodies connected by mechanical linkages and elastic elements. To model andsimulate this mechanism with MSC ADAMS programme, the author covered the following stages: constructionof the model, testing-simulation, validation, finishing, parameterization, and optimization

  11. Adsorptive removal of congo red and sunset yellow dyes from water systems by lady finger stem

    International Nuclear Information System (INIS)

    Abbas, A.; Murtaza, S.; Ayub, R.; Rehman, R.; Zahid, A.

    2012-01-01

    Summary: In this research work two anionic dyes, i.e. Congo Red and Sunset Yellow were removed successfully from aqueous media by Lady Finger stem in batch mode. Operational conditions optimization showed that agitation speed and particle size did not affect much in adsorption of these dyes; but contact time, pH, adsorbent dose and temperature of system effects the adsorption rate. Optimized conditions of adsorption for Congo Red dye were: 40 minute contact time, 8.0 pH, 0.5 g adsorbent dose, 40-60 microns mesh sized particles, 150 rpm agitation speed and 50 degree C temperature. Whereas for Sunset Yellow optimized conditions were: 30 minute contact time, 2.0 pH, 2.5 g adsorbent dose, 20-40 microns mesh sized particles, 50 rpm agitation speed and 30 degree C temperature. Suitability of equilibrium data was modulated with Langmuir, Freundlich and Temkin models and found that both physisorption and chemisorption processes play important role in adsorption of these dyes by Lady Finger stem. The results demonstrated that Lady Finger stem can be efficiently employed on larger scale wastewater treatment. (author)

  12. Wear behavior of Cu-Ag-Cr alloy wire under electrical sliding

    International Nuclear Information System (INIS)

    Jia, S.G.; Liu, P.; Ren, F.Z.; Tian, B.H.; Zheng, M.S.; Zhou, G.S.

    2005-01-01

    The wear behavior of a Cu-Ag-Cr alloy contact wire against a copper-base sintered alloy strip was investigated. Wear tests were conducted under laboratory conditions with a special sliding wear apparatus that simulated train motion under electrical current conditions. The initial microstructure of the Cu-Ag-Cr alloy contact wire was analyzed by transmission electron microscopy. Worn surfaces of the Cu-Ag-Cr alloy wire were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The results indicate that the wear rate of the Cu-Ag-Cr wire increased with increasing electrical current and sliding. Within the studied range of electrical current, the wear rate increases with increasing electrical current and sliding speed. Compared with the Cu-Ag contact wire under the same testing conditions, the Cu-Ag-Cr alloy wire has much better wear resistance. Adhesive, abrasive, and electrical erosion wear are the dominant mechanisms during the electrical sliding processes

  13. Micro-configuration Observation of Porous Bioceramic for Sliding on Intestinal Mucus Film

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The microstructure of the prepared porous bioceramic material, including surface porosity and apparent contact area with the artificial mucus film are computed and analyzed. The surface micro-configurations of the porous material before and after sliding on the mucus ftlm are observed in 2D and 3 D by digital microscopy. We describe how much mucus enters and stays within different pores, and how the porous material with rough/porous surface contacts with the mucus film ( elastic surface/gel). The presented results illustrate that the material with different porous structure can lead to different mucus suction, surface scraping and changes of contact area and condition during sliding, which will be active for high friction of robotic endoscope with the intestinal wall for intestinal locomotion.

  14. Superlubric sliding of graphene nanoflakes on graphene.

    Science.gov (United States)

    Feng, Xiaofeng; Kwon, Sangku; Park, Jeong Young; Salmeron, Miquel

    2013-02-26

    The lubricating properties of graphite and graphene have been intensely studied by sliding a frictional force microscope tip against them to understand the origin of the observed low friction. In contrast, the relative motion of free graphene layers remains poorly understood. Here we report a study of the sliding behavior of graphene nanoflakes (GNFs) on a graphene surface. Using scanning tunneling microscopy, we found that the GNFs show facile translational and rotational motions between commensurate initial and final states at temperatures as low as 5 K. The motion is initiated by a tip-induced transition of the flakes from a commensurate to an incommensurate registry with the underlying graphene layer (the superlubric state), followed by rapid sliding until another commensurate position is reached. Counterintuitively, the average sliding distance of the flakes is larger at 5 K than at 77 K, indicating that thermal fluctuations are likely to trigger their transitions from superlubric back to commensurate ground states.

  15. SlideJ: An ImageJ plugin for automated processing of whole slide images.

    Science.gov (United States)

    Della Mea, Vincenzo; Baroni, Giulia L; Pilutti, David; Di Loreto, Carla

    2017-01-01

    The digital slide, or Whole Slide Image, is a digital image, acquired with specific scanners, that represents a complete tissue sample or cytological specimen at microscopic level. While Whole Slide image analysis is recognized among the most interesting opportunities, the typical size of such images-up to Gpixels- can be very demanding in terms of memory requirements. Thus, while algorithms and tools for processing and analysis of single microscopic field images are available, Whole Slide images size makes the direct use of such tools prohibitive or impossible. In this work a plugin for ImageJ, named SlideJ, is proposed with the objective to seamlessly extend the application of image analysis algorithms implemented in ImageJ for single microscopic field images to a whole digital slide analysis. The plugin has been complemented by examples of macro in the ImageJ scripting language to demonstrate its use in concrete situations.

  16. SlideJ: An ImageJ plugin for automated processing of whole slide images.

    Directory of Open Access Journals (Sweden)

    Vincenzo Della Mea

    Full Text Available The digital slide, or Whole Slide Image, is a digital image, acquired with specific scanners, that represents a complete tissue sample or cytological specimen at microscopic level. While Whole Slide image analysis is recognized among the most interesting opportunities, the typical size of such images-up to Gpixels- can be very demanding in terms of memory requirements. Thus, while algorithms and tools for processing and analysis of single microscopic field images are available, Whole Slide images size makes the direct use of such tools prohibitive or impossible. In this work a plugin for ImageJ, named SlideJ, is proposed with the objective to seamlessly extend the application of image analysis algorithms implemented in ImageJ for single microscopic field images to a whole digital slide analysis. The plugin has been complemented by examples of macro in the ImageJ scripting language to demonstrate its use in concrete situations.

  17. Determination of the characteristics of a Schottky barrier formed by latent finger mark corrosion of brass

    International Nuclear Information System (INIS)

    Bond, J W

    2009-01-01

    The ideality factor (η) and barrier height (φ B ) for a metal-copper(I) oxide rectifying contact formed by the latent finger mark corrosion of α phase brass have been determined from forward bias I/V characteristics in the range 0.4 V ≤ V ≤ 0.55 V. Rectifying contacts formed from the finger mark deposits of different people gave η = 1.5-1.6 ± 0.1 and φ B = 0.49-0.52 ± 0.04 V. A Mott-Schottky plot of capacitance-voltage measurements in reverse bias gave the built in potential ψ bi = 0.4 ± 0.1 V, the gradient of the plot confirming the conductivity of the finger mark corrosion as p type. X-ray photoelectron spectroscopy spectra of the corrosion showed that Cu(I), Cu(II) and Zn(II) can co-exist on the surface, the Cu(I) : Cu(II) and Zn : Cu ratios determining whether a rectifying contact is formed. Initial findings suggest that when the concentration of Cu(I) dominates the Cu(I) : Cu(II) ratio (approximately 6 : 1), or when Cu(II) is absent, a rectifying contact can be formed subject to the Zn : Cu ratio being approximately 1 : 3. As the surface concentration of zinc increases, the rectifying contact is degraded until the concentration of zinc approaches that of copper when no evidence of a Schottky barrier is observed and the contact appears ohmic.

  18. Influence of Fine Motor Skill on Accuracy of Measurements Using a Handheld Sliding Caliper at Adolescents Group Aged 19-20

    Science.gov (United States)

    Brychta, Petr; Hojk, Vladimír; Hrubý, Jiří; Pilc, Jozef

    2017-10-01

    This innovate ve interdisciplinary study deals with influence of fine motor skill level (finger dexterity) of individual on his measurement results in metrology practice. The main objective of this study was determinate fine motor skill level of individuals using a motor test. Further determinate the potential effect of different fine motor skill levels on accuracy of measuring using a mechanical handheld sliding caliper. Fine motor skill test and metrological test were implemented. Pursuant the results of fine motor skill test were probands divided into 2 groups. The groups are significantly different on accuracy of measurement (p=0,006). Pearson coefficient shows a significant correlation r = - 0.66 between the Purdue Pegboard test and a measurement error. Results confirmed that the fine motor skill of the upper limbs (especially finger coordination) significantly influence accuracy of measurement using a mechanical handheld sliding caliper.

  19. Chaos control using sliding-mode theory

    International Nuclear Information System (INIS)

    Nazzal, Jamal M.; Natsheh, Ammar N.

    2007-01-01

    Chaos control means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, a nonlinear Sliding-Mode Controller (SMC) is presented. Two nonlinear chaotic systems are chosen to be our case study in this paper, the well known Chua's circuit and Lorenz system. The study shows the effectiveness of the designed nonlinear Sliding-Mode Controller

  20. The Incidence of Finger Ridge Counts among the Christian ...

    African Journals Online (AJOL)

    user

    higher among the males than females, with sex difference significant ,they were compared with ... Finger prints were taken by a USB finger print reader (Biometric Scanner).According .... "Digital dermatoglyphics of three caste groups of Mysore.

  1. Viscous fingering of HCI through gastric mucin

    Science.gov (United States)

    Bhaskar, K. Ramakrishnan; Garik, Peter; Turner, Bradley S.; Bradley, James Douglas; Bansil, Rama; Stanley, H. Eugene; Lamont, J. Thomas

    1992-12-01

    THE HCI in the mammalian stomach is concentrated enough to digest the stomach itself, yet the gastric epithelium remains undamaged. One protective factor is gastric mucus, which forms a protective layer over the surface epithelium1-4 and acts as a diffusion barrier5,6 Bicarbonate ions secreted by the gastric epithelium7 are trapped in the mucus gel, establishing a gradient from pH 1-2 at the lumen to pH 6-7 at the cell surface8-10. How does HCI, secreted at the base of gastric glands by parietal cells, traverse the mucus layer without acidifying it? Here we demonstrate that injection of HCI through solutions of pig gastric mucin produces viscous fingering patterns11-18 dependent on pH, mucin concentration and acid flow rate. Above pH 4, discrete fingers are observed, whereas below pH 4, HCI neither penetrates the mucin solution nor forms fingers. Our in vitro results suggest that HCI secreted by the gastric gland can penetrate the mucus gel layer (pH 5-7) through narrow fingers, whereas HC1 in the lumen (pH 2) is prevented from diffusing back to the epithelium by the high viscosity of gastric mucus gel on the luminal side.

  2. Designing Fingers in Simulation based on Imprints

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Krüger, Norbert; Werner, Andrzej

    process of doing so. This method takes root in the idea of using the imprint to produce the finger geometry. We furthermore provide a verification of our newly introduced imprinting method and a comparison to the previously introduced parametrized geometry method. This verification is done through a set...

  3. Designing Fingers in Simulation based on Imprints

    DEFF Research Database (Denmark)

    Wiuf Schwartz, Lukas Christoffer Malte; Wolniakowski, Adam; Werner, Andrzej

    2017-01-01

    process of doing so. This method takes root in the idea of using the imprint to produce the finger geometry. We furthermore provide a verification of our newly introduced imprinting method and a comparison to the previously introduced parametrized geometry method. This verification is done through a set...

  4. Finger Search in Grammar-Compressed Strings

    DEFF Research Database (Denmark)

    Bille, Philip; Christiansen, Anders Roy; Cording, Patrick Hagge

    2016-01-01

    random access, that is, given a position in the original uncompressed string report the character at that position. In this paper we study the random access problem with the finger search property, that is, the time for a random access query should depend on the distance between a specified index f...

  5. Compact Tactile Sensors for Robot Fingers

    Science.gov (United States)

    Martin, Toby B.; Lussy, David; Gaudiano, Frank; Hulse, Aaron; Diftler, Myron A.; Rodriguez, Dagoberto; Bielski, Paul; Butzer, Melisa

    2004-01-01

    Compact transducer arrays that measure spatial distributions of force or pressure have been demonstrated as prototypes of tactile sensors to be mounted on fingers and palms of dexterous robot hands. The pressure- or force-distribution feedback provided by these sensors is essential for the further development and implementation of robot-control capabilities for humanlike grasping and manipulation.

  6. Clubbed fingers: the claws we lost?

    NARCIS (Netherlands)

    Brouwers, A.A.M.; Vermeij-Keers, C.; Zoelen, E.J.J. van; Gooren, L.J.G.

    2004-01-01

    Clubbed digits resemble the human embryonic fingers and toes, which took like the digits of a claw. Clubbed digits, thus, may represent the return of the embryonic claw and may even represent the claws man has lost during evolution, if ontogenesis realty recapitulates phylogenesis. We put forward

  7. Task specificity of finger dexterity tests

    NARCIS (Netherlands)

    Berger, M.A.M.; Krul, A.; Daanen, H.A.M.

    2009-01-01

    Finger dexterity tests are generally used to assess performance decrease due to gloves, cold and pathology. It is generally assumed that the O’Connor and Purdue Pegboard test yield similar results. In this experiment we compared these two tests for dry conditions without gloves, and for dry and wet

  8. Task specificity of finger dexterity tests

    NARCIS (Netherlands)

    Berger, M.A.M.; Krul, A.J.; Daanen, H.A.M.

    2009-01-01

    Finger dexterity tests are generally used to assess performance decrease due to gloves, cold and pathology. It is generally assumed that the O'Connor and Purdue Pegboard test yield similar results. In this experiment we compared these two tests for dry conditions without gloves, and for dry and wet

  9. Tribology of the lubricant quantized sliding state.

    Science.gov (United States)

    Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

    2009-11-07

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.

  10. Preparing Scientific Papers, Posters, and Slides.

    Science.gov (United States)

    Lefor, Alan Kawarai; Maeno, Misato

    2016-01-01

    Publications and presentations are important in academic medicine. The ability to present information in a standard fashion is critically important. Papers, posters, and slides must be prepared appropriately to maximize their chance of being accepted. The first step is to use word processing software correctly. English language usage must conform to standard scientific English usage. Abbreviations should be avoided as much as possible. Numerical data must be presented with the appropriate number of significant figures. The first step in preparing a paper is to decide the target journal. Papers should always be written in 12 point Times New Roman font, while slides and posters should be in Arial or Helvetica. The Results section must contain actual data with appropriate statistical analysis. Take great care to prepare figures and tables according to the journal's instructions. Posters must be prepared to allow easy reading at a distance of 2m. Use a white background and dark letters. The majority of the area of your poster should be Results, and there is no need to include the abstract or references on a poster. Slide presentations should be limited to about one slide for each minute of the talk. Avoid the use of animations and excessive use of color. Do not use abbreviations on slides. Following these simple guidelines will meet the requirements of most journals and allow your audience to appreciate the data on your posters and slides. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  11. Self-Organized Traveling Chemo-Hydrodynamic Fingers Triggered by a Chemical Oscillator.

    Science.gov (United States)

    Escala, D M; Budroni, M A; Carballido-Landeira, J; De Wit, A; Muñuzuri, A P

    2014-02-06

    Pulsatile chemo-hydrodynamic patterns due to a coupling between an oscillating chemical reaction and buoyancy-driven hydrodynamic flows can develop when two solutions of separate reactants of the Belousov-Zhabotinsky reaction are put in contact in the gravity field and conditions for chemical oscillations are met in the contact zone. In regular oscillatory conditions, localized periodic changes in the concentration of intermediate species induce pulsatile density gradients, which, in turn, generate traveling convective fingers breaking the transverse symmetry. These patterns are the self-organized result of a genuine coupling between chemical and hydrodynamic modes.

  12. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  13. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    International Nuclear Information System (INIS)

    Hansen, E. K.

    2015-01-01

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  14. Study on the fatigue crack initiation life under spherical contact

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Joo; Kim, Tae Wan [Busan National Univ., Busan (Korea, Republic of); Lee, Mun Ju [Samsung Electronics Co., Ltd., Suwon (Korea, Republic of)

    2001-08-01

    In case of contact fatigue, the accurate calculation of surface tractions and subsurface stress is essential to the prediction of crack initiation life. Surface tractions influencing shear stress amplitude have been obtained by contact analysis based on influence function. Subsurface stress has been obtained by using rectangular patch solutions. In this study, to simulate asperity contact under sliding condition, the tip of asperity was simulated by sphere and to calculate crack initiation life in the substrate, dislocation pileup theory was used.

  15. Study on the fatigue crack initiation life under spherical contact

    International Nuclear Information System (INIS)

    Cho, Yong Joo; Kim, Tae Wan; Lee, Mun Ju

    2001-01-01

    In case of contact fatigue, the accurate calculation of surface tractions and subsurface stress is essential to the prediction of crack initiation life. Surface tractions influencing shear stress amplitude have been obtained by contact analysis based on influence function. Subsurface stress has been obtained by using rectangular patch solutions. In this study, to simulate asperity contact under sliding condition, the tip of asperity was simulated by sphere and to calculate crack initiation life in the substrate, dislocation pileup theory was used

  16. LANL Contacts

    Science.gov (United States)

    : (505) 665-3664 ethics@lanl.gov Journalist queries Communications Office (505) 667-7000 Media contacts programs and employee resources. General Employee directory Emergency communication Communications Office (505) 667-7000 Ethics & Audits Internal Audit: (505) 665-3104 Ethics Office: (505) 667-7506 Fax

  17. Dorsal finger texture recognition: Investigating fixed-length SURF

    DEFF Research Database (Denmark)

    Hartung, Daniel; Kückelhahn, Jesper

    2012-01-01

    We seek to create fixed-length features from dorsal finger skin images extracted by the SURF interest point detector to combine it in the privacy enhancing helper data scheme. The source of the biometric samples is the GUC45 database which features finger vein, fingerprint and dorsal finger skin...

  18. Association Between Finger Clubbing and Chronic Lung Disease in ...

    African Journals Online (AJOL)

    Finger clubbed patients had higher risk of hypoxemia (46.7%), pulmonary hypertension (46.7%) and advanced disease in WHO stage III/ IV (91.7%) compared to non-finger clubbed patients. Finger clubbed patients had lower CD4 cells count and percentage (median 369cells, 13%) compared to non-clubbed patients ...

  19. The Change in Fingertip Contact Area as a Novel Proprioceptive Cue.

    Science.gov (United States)

    Moscatelli, Alessandro; Bianchi, Matteo; Serio, Alessandro; Terekhov, Alexander; Hayward, Vincent; Ernst, Marc O; Bicchi, Antonio

    2016-05-09

    Humans, many animals, and certain robotic hands have deformable fingertip pads [1, 2]. Deformable pads have the advantage of conforming to the objects that are being touched, ensuring a stable grasp for a large range of forces and shapes. Pad deformations change with finger displacements during touch. Pushing a finger against an external surface typically provokes an increase of the gross contact area [3], potentially providing a relative motion cue, a situation comparable to looming in vision [4]. The rate of increase of the area of contact also depends on the compliance of the object [5]. Because objects normally do not suddenly change compliance, participants may interpret an artificially induced variation in compliance, which coincides with a change in the gross contact area, as a change in finger displacement, and consequently they may misestimate their finger's position relative to the touched object. To test this, we asked participants to compare the perceived displacements of their finger while contacting an object varying pseudo-randomly in compliance from trial to trial. Results indicate a bias in the perception of finger displacement induced by the change in compliance, hence in contact area, indicating that participants interpreted the altered cutaneous input as a cue to proprioception. This situation highlights the capacity of the brain to take advantage of knowledge of the mechanical properties of the body and of the external environment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Self-powered, ultra-sensitive, flexible tactile sensors based on contact electrification

    Science.gov (United States)

    Wang, Zhong Lin; Zhu, Guang

    2018-03-20

    A tactile sensor for sensing touch from a human finger includes a triboelectric layer and includes a material that becomes electrically charged after being in contact with the finger. The first side of a first conductive layer is in contact with the second side of triboelectric layer. The first side of a dielectric layer is in contact with the first conductive layer and the second side of the dielectric layer is in contact with a second conductive layer. When the triboelectric layer becomes electrically charged after being in contact with the finger, the first conductive layer and the second conductive layer are subjected to an electric field, which has a first field strength at the first conductive layer and a second field strength, different from the first field strength, at the second conductive layer. A plurality of tactile sensors can be arranged as a keyboard.

  1. Evaluation of stresses generated in steel finger joint of bridge by X-ray stress measurement

    International Nuclear Information System (INIS)

    Kohri, Ami; Kawano, Yutaka; Nishido, Takayuki

    2017-01-01

    In a steel bridge, the evaluation of the stress generated in the finger joint without a gap to absorb temperature change can be an index when evaluating the remaining life. This study chose as the object the finger joint of a diagonal bridge, where the generated stress state is considered to be more complicated, prepared a finger joint test specimen that simulated an actual part, and performed a load test. For judgment, FEM analysis, non-destructive X-ray stress measurement, and measurement of the generated stress using strain gauge were applied. Compared with the FEM analysis results, the difference in the stress value was generated due to the difference in the contact state, but the trends of the stress distribution were equivalent. In addition, the same measurement value as the strain gauge was obtained, and the validity of the X-ray stress measurement method was confirmed. As a result, it was found that the stress measurement method by X-ray is effective for measuring the generated stress including the residual stress of the finger joint without gap at a bridge. (A.O.)

  2. Whole Slide Images for primary diagnostics in pathology

    NARCIS (Netherlands)

    Al-Janabi, S.

    2013-01-01

    Whole slide imaging is the process of digitizing glass slides resulting in the creation of Whole Slide Images (WSI). WSI are usually explored with the aid of an image viewer in a manner that closely simulates examining glass slides with a conventional microscope, permitting the manipulation of an

  3. Semantic focusing allows fully automated single-layer slide scanning of cervical cytology slides.

    Directory of Open Access Journals (Sweden)

    Bernd Lahrmann

    Full Text Available Liquid-based cytology (LBC in conjunction with Whole-Slide Imaging (WSI enables the objective and sensitive and quantitative evaluation of biomarkers in cytology. However, the complex three-dimensional distribution of cells on LBC slides requires manual focusing, long scanning-times, and multi-layer scanning. Here, we present a solution that overcomes these limitations in two steps: first, we make sure that focus points are only set on cells. Secondly, we check the total slide focus quality. From a first analysis we detected that superficial dust can be separated from the cell layer (thin layer of cells on the glass slide itself. Then we analyzed 2,295 individual focus points from 51 LBC slides stained for p16 and Ki67. Using the number of edges in a focus point image, specific color values and size-inclusion filters, focus points detecting cells could be distinguished from focus points on artifacts (accuracy 98.6%. Sharpness as total focus quality of a virtual LBC slide is computed from 5 sharpness features. We trained a multi-parameter SVM classifier on 1,600 images. On an independent validation set of 3,232 cell images we achieved an accuracy of 94.8% for classifying images as focused. Our results show that single-layer scanning of LBC slides is possible and how it can be achieved. We assembled focus point analysis and sharpness classification into a fully automatic, iterative workflow, free of user intervention, which performs repetitive slide scanning as necessary. On 400 LBC slides we achieved a scanning-time of 13.9±10.1 min with 29.1±15.5 focus points. In summary, the integration of semantic focus information into whole-slide imaging allows automatic high-quality imaging of LBC slides and subsequent biomarker analysis.

  4. Semantic focusing allows fully automated single-layer slide scanning of cervical cytology slides.

    Science.gov (United States)

    Lahrmann, Bernd; Valous, Nektarios A; Eisenmann, Urs; Wentzensen, Nicolas; Grabe, Niels

    2013-01-01

    Liquid-based cytology (LBC) in conjunction with Whole-Slide Imaging (WSI) enables the objective and sensitive and quantitative evaluation of biomarkers in cytology. However, the complex three-dimensional distribution of cells on LBC slides requires manual focusing, long scanning-times, and multi-layer scanning. Here, we present a solution that overcomes these limitations in two steps: first, we make sure that focus points are only set on cells. Secondly, we check the total slide focus quality. From a first analysis we detected that superficial dust can be separated from the cell layer (thin layer of cells on the glass slide) itself. Then we analyzed 2,295 individual focus points from 51 LBC slides stained for p16 and Ki67. Using the number of edges in a focus point image, specific color values and size-inclusion filters, focus points detecting cells could be distinguished from focus points on artifacts (accuracy 98.6%). Sharpness as total focus quality of a virtual LBC slide is computed from 5 sharpness features. We trained a multi-parameter SVM classifier on 1,600 images. On an independent validation set of 3,232 cell images we achieved an accuracy of 94.8% for classifying images as focused. Our results show that single-layer scanning of LBC slides is possible and how it can be achieved. We assembled focus point analysis and sharpness classification into a fully automatic, iterative workflow, free of user intervention, which performs repetitive slide scanning as necessary. On 400 LBC slides we achieved a scanning-time of 13.9±10.1 min with 29.1±15.5 focus points. In summary, the integration of semantic focus information into whole-slide imaging allows automatic high-quality imaging of LBC slides and subsequent biomarker analysis.

  5. Residual Stresses and Sliding Wear.

    Science.gov (United States)

    1982-05-25

    case of rolling contact, taking into account strain hardening during plastic deformation. ..-s calculations (forSAE 52100 at a hardness level of 58.5 R...can reach -800- 1000 MPa. If 033 was comparable to these values, it would indeed effect the wear rate. It is evident that an experimental deter...cc o 40 1 °2 00 I I +A ) S l~lll0 44MUK I CQ E3 e0 El 0 Uc 00 E3 (3 80 j40 c (vclq) SSHHI +ce ce mCQ ce (2E e0 4El EJ) E - 0 El 0 E0 .. t El 0 (vdNp

  6. Sliding right into disaster : left-to-right sliding windows leak

    NARCIS (Netherlands)

    Bernstein, D.J.; Breitner, J.; Genkin, D.; Groot Bruinderink, L.; Heninger, N.; Lange, T.; van Vredendaal, C.; Yarom, Y.; Fischer, W.; Homma, N.

    2017-01-01

    It is well known that constant-time implementations of modular exponentiation cannot use sliding windows. However, software libraries such as Libgcrypt, used by GnuPG, continue to use sliding windows. It is widely believed that, even if the complete pattern of squarings and multiplications is

  7. Accurate Sliding-Mode Control System Modeling for Buck Converters

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2007-01-01

    This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter....

  8. Remote Controlling and Monitoring of Microscopic Slides

    International Nuclear Information System (INIS)

    Mustafa, G.; Qadri, M.T.; Daraz, U.

    2016-01-01

    Remotely controlled microscopic slide was designed using especial Graphical User Interface (GUI) which interfaces the user at remote location with the real microscope using site and the user can easily view and control the slide present on the microscope's stage. Precise motors have been used to allow the movement in all the three dimensions required by a pathologist. The pathologist can easily access these slides from any remote location and so the physical presence of the pathologist is now made easy. This invention would increase the health care efficiency by reducing the time and cost of diagnosis, making it very easy to get the expert's opinion and supporting the pathologist to relocate himself for his work. The microscope is controlled with computer with an attractive Graphical User Interface (GUI), through which a pathologist can easily monitor, control and record the image of the slide. The pathologist can now do his work regardless of his location, time, cost and physically presence of lab equipment. The technology will help the specialist in viewing the patients slide from any location in the world. He would be able to monitor and control the stage. This will also help the pathological laboratories in getting opinion from senior pathologist who are present at any far location in the world. This system also reduces the life risks of the patients. (author)

  9. Long-term subglacial sliding patterns based on a sliding law with cavitation

    DEFF Research Database (Denmark)

    Ugelvig, Sofie Vej; Egholm, D.L.

    In ice-sheet models and glacial landscape evolution models, subglacial sliding rates are often related to basal shear stress by a power-law. However, the power-law relationship implies that the subglacial bed can provide unlimited levels of basal drag as sliding rates increases, which is recognized...... as an inadequate assumption, particularly when the effects of subglacial cavities are considered (Schoof 2005). We have implemented a glacial sliding law suggested by Schoof (2005) in a depth-integrated higher-order ice-sheet model (Egholm et al. 2011) and coupled this to a model for glacial hydrology. The sliding...... law includes an upper bound to the basal drag and depends on the effects of longitudinal and transverse stress components for obtaining force balance along the glacier bed. Computational experiments indicate that high annually averaged sliding rates concentrate along valley sides when basal melt...

  10. Reciprocating sliding wear of Inconel 600 tubing in room temperature air

    International Nuclear Information System (INIS)

    Kim, Hun; Choi, Jong Hyun; Kim, Jun Ki; Hong, Hyun Seon; Kim, Seon Jin

    2003-01-01

    The sliding wear behavior of the material of a steam generator in a nuclear power station (Inconel 600) was investigated at room temperature. Effects of the wear parameters such as material combination, sliding distance and contact stress were examined with various mating materials including 304 austenitic stainless steel, Inconel 600 and Al-Cu alloy 2011. In the prediction of the wear volume by Archard's wear equation, the standard error range was calculated to be ±4.04x10 -9 m 3 and the reliability to be 71.9% for the combination of Inconel 600 and 304 stainless steel. The error range was considered to be relatively broad because the wear coefficient in Archard's equation was assumed to be a constant, regardless of the changes in the mechanical properties during the wear. In the present study, the sliding wear behavior turned out to be influenced by the material combination; the wear volume of 304 stainless steel did not linearly increase with the sliding distance, while that of other material combinations exhibited linear increases. Based on the experimental results, the wear coefficient was modified as a function of the sliding distance. The calculation with the modified wear equation showed that the error range narrowed down to ±2.60x10 -9 m 3 and the reliability increased to 75.3%, compared to Archard's original equation

  11. Frictional sliding tests on combined coal-rock samples

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2014-06-01

    Full Text Available A test system was developed to understand the sliding mechanism of coal-rock structure. The test system was composed by a double-shear testing model and an acousto-optic monitoring system in association with a digital camera and an acoustic emission (AE instrument. The tests can simulate the movement of activated faults and the sliding in coal-rock structure. In this regard, instable sliding conditions of coal-rock samples, sliding types under different conditions, displacement evolution law, and AE characteristics during sliding process were investigated. Several sliding types were monitored in the tests, including unstable continuous sliding, unstable discontinuous sliding, and stable sliding. The sliding types have close relation with the axial loads and loading rates. Larger axial load and smaller loading rate mean that unstable sliding is less likely to occur. The peak shear stress was positively correlated with the axial load when sliding occurred, whereas the displacement induced by unstable sliding was uncorrelated with the axial load. A large number of AE events occurred before sliding, and the AE rate decreased after stable sliding. The results show that the tests can well simulate the process of structural instability in a coal bump, and are helpful in the understanding of fault activation and the physical processes during squeezing process of roof and floor.

  12. An Ice Track Equipped with Optical Sensors for Determining the Influence of Experimental Conditions on the Sliding Velocity

    Science.gov (United States)

    Lungevics, J.; Jansons, E.; Gross, K. A.

    2018-02-01

    The ability to slide on ice has previously focused on the measurement of friction coefficient rather than the actual sliding velocity that is affected by it. The performance can only be directly measured by the sliding velocity, and therefore the objective was to design and setup a facility to measure velo-city, and determine how experimental conditions affect it. Optical sensors were placed on an angled ice track to provide sliding velocity measurements along three sections and the velocity for the total sliding distance. Experimental conditions included the surface roughness, ambient temperature and load. The effect of roughness was best reported with a Criterion of Contact that showed a similar sliding velocity for metal blocks abraded with sand paper smoother than 600 grit. Searching for the effect of temperature, the highest sliding velocity coincided with the previously reported lowest coefficient of ice friction. Load showed the greatest velocity increase at temperatures closer to the ice melting point suggesting that in such conditions metal block overcame friction forces more easily than in solid friction. Further research needs to be conducted on a longer ice track, with larger metal surfaces, heavier loads and higher velocities to determine how laboratory experiments can predict real-life situations.

  13. An Ice Track Equipped with Optical Sensors for Determining the Influence of Experimental Conditions on the Sliding Velocity

    Directory of Open Access Journals (Sweden)

    Lungevics J.

    2018-02-01

    Full Text Available The ability to slide on ice has previously focused on the measurement of friction coefficient rather than the actual sliding velocity that is affected by it. The performance can only be directly measured by the sliding velocity, and therefore the objective was to design and setup a facility to measure velo-city, and determine how experimental conditions affect it. Optical sensors were placed on an angled ice track to provide sliding velocity measurements along three sections and the velocity for the total sliding distance. Experimental conditions included the surface roughness, ambient temperature and load. The effect of roughness was best reported with a Criterion of Contact that showed a similar sliding velocity for metal blocks abraded with sand paper smoother than 600 grit. Searching for the effect of temperature, the highest sliding velocity coincided with the previously reported lowest coefficient of ice friction. Load showed the greatest velocity increase at temperatures closer to the ice melting point suggesting that in such conditions metal block overcame friction forces more easily than in solid friction. Further research needs to be conducted on a longer ice track, with larger metal surfaces, heavier loads and higher velocities to determine how laboratory experiments can predict real-life situations.

  14. Analysis of prosody in finger braille using electromyography.

    Science.gov (United States)

    Miyagi, Manabi; Nishida, Masafumi; Horiuchi, Yasuo; Ichikawa, Akira

    2006-01-01

    Finger braille is one of the communication methods for the deaf blind. The interpreter types braille codes on the fingers of deaf blind. Finger braille seems to be the most suitable medium for real-time communication by its speed and accuracy of transmitting characters. We hypothesize that the prosody information exists in the time structure and strength of finger braille typing. Prosody is the paralinguistic information that has functions to transmit the sentence structure, prominence, emotions and other form of information in real time communication. In this study, we measured the surface electromyography (sEMG) of finger movement to analyze the typing strength of finger braille. We found that the typing strength increases at the beginning of a phrase and a prominent phrase. The result shows the possibility that the prosody in the typing strength of finger braille can be applied to create an interpreter system for the deafblind.

  15. A Diabetic Elderly Man with Finger Ulcer.

    Science.gov (United States)

    Mohamad, Noraini; Badrin, Salziyan; Wan Abdullah, Wan Noor Hasbee

    2018-03-01

    Fixed cutaneous sporotrichosis is a differential diagnosis that can be considered in diabetic patients who present with a poorly healing ulcer. Although its prevalence is low, it can occur in patients with immunocompromised status. Here we report a case of a 70-year-old man with diabetes mellitus who presented with a 1-month history of an unhealed ulcer over the tip of his left middle finger. He experienced a cat bite over his left middle finger 1 month prior to the appearance of the lesion. A skin biopsy revealed the presence of Sporothrix schenckii . Oral itraconazole 200 mg twice daily was started empirically and the patient showed marked improvement in the skin lesion after 2 months of therapy.

  16. Finger vein recognition with personalized feature selection.

    Science.gov (United States)

    Xi, Xiaoming; Yang, Gongping; Yin, Yilong; Meng, Xianjing

    2013-08-22

    Finger veins are a promising biometric pattern for personalized identification in terms of their advantages over existing biometrics. Based on the spatial pyramid representation and the combination of more effective information such as gray, texture and shape, this paper proposes a simple but powerful feature, called Pyramid Histograms of Gray, Texture and Orientation Gradients (PHGTOG). For a finger vein image, PHGTOG can reflect the global spatial layout and local details of gray, texture and shape. To further improve the recognition performance and reduce the computational complexity, we select a personalized subset of features from PHGTOG for each subject by using the sparse weight vector, which is trained by using LASSO and called PFS-PHGTOG. We conduct extensive experiments to demonstrate the promise of the PHGTOG and PFS-PHGTOG, experimental results on our databases show that PHGTOG outperforms the other existing features. Moreover, PFS-PHGTOG can further boost the performance in comparison with PHGTOG.

  17. Finger Vein Recognition with Personalized Feature Selection

    Directory of Open Access Journals (Sweden)

    Xianjing Meng

    2013-08-01

    Full Text Available Finger veins are a promising biometric pattern for personalized identification in terms of their advantages over existing biometrics. Based on the spatial pyramid representation and the combination of more effective information such as gray, texture and shape, this paper proposes a simple but powerful feature, called Pyramid Histograms of Gray, Texture and Orientation Gradients (PHGTOG. For a finger vein image, PHGTOG can reflect the global spatial layout and local details of gray, texture and shape. To further improve the recognition performance and reduce the computational complexity, we select a personalized subset of features from PHGTOG for each subject by using the sparse weight vector, which is trained by using LASSO and called PFS-PHGTOG. We conduct extensive experiments to demonstrate the promise of the PHGTOG and PFS-PHGTOG, experimental results on our databases show that PHGTOG outperforms the other existing features. Moreover, PFS-PHGTOG can further boost the performance in comparison with PHGTOG.

  18. Granular fingering as a mechanism for ridge formation in debris avalanche deposits: Laboratory experiments and implications for Tutupaca volcano, Peru

    Science.gov (United States)

    Valderrama, P.; Roche, O.; Samaniego, P.; van Wyk des Vries, B.; Araujo, G.

    2018-01-01

    The origin of subparallel, regularly-spaced longitudinal ridges often observed at the surface of volcanic and other rock avalanche deposits remains unclear. We addressed this issue through analogue laboratory experiments on flows of bi-disperse granular mixtures, because this type of flow is known to exhibit granular fingering that causes elongated structures resembling the ridges observed in nature. We considered four different mixtures of fine (300-400 μm) glass beads and coarse (600-710 μm to 900-1000 μm) angular crushed fruit stones, with particle size ratios of 1.9-2.7 and mass fractions of the coarse component of 5-50 wt%. The coarse particles segregated at the flow surface and accumulated at the front where flow instabilities with a well-defined wavelength grew. These formed granular fingers made of coarse-rich static margins delimiting fines-rich central channels. Coalescence of adjacent finger margins created regular spaced longitudinal ridges, which became topographic highs as finger channels drained at final emplacement stages. Three distinct deposit morphologies were observed: 1) Joined fingers with ridges were formed at low (≤ 1.9) size ratio and moderate (10-20 wt%) coarse fraction whereas 2) separate fingers or 3) poorly developed fingers, forming series of frontal lobes, were created at larger size ratios and/or higher coarse contents. Similar ridges and lobes are observed at the debris avalanche deposits of Tutupaca volcano, Peru, suggesting that the processes operating in the experiments can also occur in nature. This implies that volcanic (and non-volcanic) debris avalanches can behave as granular flows, which has important implications for interpretation of deposits and for modeling. Such behaviour may be acquired as the collapsing material disaggregates and forms a granular mixture composed by a right grain size distribution in which particle segregation can occur. Limited fragmentation and block sliding, or grain size distributions

  19. Unevenness of Sliding Surface of Overhead Rigid Conductor Lines and Method for Reducing Unevenness

    Science.gov (United States)

    Aboshi, Mitsuo; Shimizu, Masashi

    Rigid conductor lines are used in many subways, because the use of such conductor lines reduces the risk of accidents and because less space is required for their installation. However, as the unevenness of the sliding surface of the rigid conductor lines significantly influences the fluctuations in the contact force between pantographs and contact lines, it is necessary to decrease the unevenness at the construction as well as the maintenance stages. In order to investigate the installation accuracy of overhead rigid conductor lines, we have developed a device that accurately and continuously measures the unevenness of the sliding surface. By using this measuring device, we have confirmed that the unevenness of the sliding surface depends on various factors such as the sag between the support points, the deformation of the aluminum base or the conductive rail in the case of a long wavelength, the slight sagging unevenness between the bolts of the long ear, the undulating wear etc. This paper describes the actual unevenness conditions and the technical methods for decreasing the unevenness of the sliding surface of overhead rigid conductor lines.

  20. Finger Search in the Implicit Model

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Nielsen, Jesper Asbjørn Sindahl; Truelsen, Jakob

    2012-01-01

    , and delete in times $\\mathcal{O}(q(t))$, $\\mathcal{O}(q^{-1}(\\log n)\\log n)$, $\\mathcal{O}(\\log n)$, and $\\mathcal{O}(\\log n)$, respectively, for any q(t) = Ω(logt). Finally we show that the search operation must take Ω(logn) time for the special case where the finger is always changed to the element...

  1. NEMD simulations for ductile metal sliding

    Energy Technology Data Exchange (ETDEWEB)

    Hammerberg, James E [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Ravelo, Ramon J [Los Alamos National Laboratory; Holian, Brad L [Los Alamos National Laboratory

    2011-01-31

    We have studied the sliding behavior for a 19 M Al(110)/Al(110) defective crystal at 15 GPa as a function of relative sliding velocity. The general features are qualitatively similar to smaller scale (1.4 M) atom simulations for Al(111)/Al(110) nondefective single crystal sliding. The critical velocity, v{sub c}, is approximately the same for the defective crystal as the size scaled v{sub c}. The lower velocity tangential force is depressed relative to the perfect crystal. The critical temperature, T*, is depressed relative to the perfect crystal. These conclusions are consistent with a lower value for f{sub c} for the defective crystal. The detailed features of structural transformation and the high velocity regime remain to be mapped.

  2. Visual Foraging With Fingers and Eye Gaze

    Directory of Open Access Journals (Sweden)

    Ómar I. Jóhannesson

    2016-03-01

    Full Text Available A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a The fact that a sizeable number of observers (in particular during gaze foraging had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints.

  3. Fingering instabilities in bacterial community phototaxis

    Science.gov (United States)

    Vps, Ritwika; Man Wah Chau, Rosanna; Casey Huang, Kerwyn; Gopinathan, Ajay

    Synechocystis sp PCC 6803 is a phototactic cyanobacterium that moves directionally in response to a light source. During phototaxis, these bacterial communities show emergent spatial organisation resulting in the formation of finger-like projections at the propagating front. In this study, we propose an analytical model that elucidates the underlying physical mechanisms which give rise to these spatial patterns. We describe the migrating front during phototaxis as a one-dimensional curve by considering the effects of phototactic bias, diffusion and surface tension. By considering the propagating front as composed of perturbations to a flat solution and using linear stability analysis, we predict a critical bias above which the finger-like projections appear as instabilities. We also predict the wavelengths of the fastest growing mode and the critical mode above which the instabilities disappear. We validate our predictions through comparisons to experimental data obtained by analysing images of phototaxis in Synechocystis communities. Our model also predicts the observed loss of instabilities in taxd1 mutants (cells with inactive TaxD1, an important photoreceptor in finger formation), by considering diffusion in mutually perpendicular directions and a lower, negative bias.

  4. Fusarium verticillioides from finger millet in Uganda.

    Science.gov (United States)

    Saleh, Amgad A; Esele, J P; Logrieco, Antonio; Ritieni, Alberto; Leslie, John F

    2012-01-01

    Finger millet (Eleusine coracana) is a subsistence crop grown in Sub-Saharan Africa and the Indian Sub-continent. Fusarium species occurring on this crop have not been reported. Approximately 13% of the Fusarium isolates recovered from finger millet growing at three different locations in eastern Uganda belong to Fusarium verticillioides, and could produce up to 18,600 µg/g of total fumonisins when cultured under laboratory conditions. These strains are all genetically unique, based on AFLP analyses, and form fertile perithecia when crossed with the standard mating type tester strains for this species. All but one of the strains is female-fertile and mating-type segregates 13:20 Mat-1:Mat-2. Three new sequences of the gene encoding translation elongation factor 1-α were found within the population. These results indicate a potential health risk for infants who consume finger millet gruel as a weaning food, and are consistent with the hypothesis that F. verticillioides originated in Africa and not in the Americas, despite its widespread association with maize grown almost anywhere worldwide.

  5. Palm to Finger Ulnar Sensory Nerve Conduction.

    Science.gov (United States)

    Davidowich, Eduardo; Nascimento, Osvaldo J M; Orsini, Marco; Pupe, Camila; Pessoa, Bruno; Bittar, Caroline; Pires, Karina Lebeis; Bruno, Carlos; Coutinho, Bruno Mattos; de Souza, Olivia Gameiro; Ribeiro, Pedro; Velasques, Bruna; Bittencourt, Juliana; Teixeira, Silmar; Bastos, Victor Hugo

    2015-12-29

    Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

  6. Palm to finger ulnar sensory nerve conduction

    Directory of Open Access Journals (Sweden)

    Eduardo Davidowich

    2015-12-01

    Full Text Available Ulnar neuropathy at the wrist (UNW is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

  7. Develop and Manufacture an airlock sliding tray

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Cindy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-26

    The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already tested and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.

  8. Bedrock erosion by sliding wear in channelized granular flow

    Science.gov (United States)

    Hung, C. Y.; Stark, C. P.; Capart, H.; Smith, B.; Maia, H. T.; Li, L.; Reitz, M. D.

    2014-12-01

    Boundary forces generated by debris flows can be powerful enough to erode bedrock and cause considerable damage to infrastructure during runout. Bedrock wear can be separated into impact and sliding wear processes. Here we focus on sliding wear. We have conducted experiments with a 40-cm-diameter grainflow-generating rotating drum designed to simulate dry channelized debris flows. To generate sliding erosion, we placed a 20-cm-diameter bedrock plate axially on the back wall of the drum. The rotating drum was half filled with 2.3-mm-diameter grains, which formed a thin grain-avalanching layer with peak flow speed and depth close to the drum axis. The whole experimental apparatus was placed on a 100g-ton geotechnical centrifuge and, in order to scale up the stress level, spun to a range of effective gravity levels. Rates and patterns of erosion of the bedrock plate were mapped after each experiment using 3d micro-photogrammetry. High-speed video and particle tracking were employed to measure granular flow dynamics. The resulting data for granular velocities and flow geometry were used to estimate impulse exchanges and forces on the bedrock plate. To address some of the complexities of granular flow under variable gravity levels, we developed a continuum model framed around a GDR MiDi rheology. This model allowed us to scale up boundary forcing while maintaining the same granular flow regime, and helped us to understand important aspects of the flow dynamics including e.g. fluxes of momentum and kinetic energy. In order to understand the detailed processes of boundary forcing, we performed numerical simulations with a new contact dynamics model. This model confirmed key aspects of our continuum model and provided information on second-order behavior such as fluctuations in the forces acting on the wall. By combining these measurements and theoretical analyses, we have developed and calibrated a constitutive model for sliding wear that is a threshold function of

  9. In situ observation of a hydrogel-glass interface during sliding friction.

    Science.gov (United States)

    Yamamoto, Tetsurou; Kurokawa, Takayuki; Ahmed, Jamil; Kamita, Gen; Yashima, Shintaro; Furukawa, Yuichiro; Ota, Yuko; Furukawa, Hidemitsu; Gong, Jian Ping

    2014-08-14

    Direct observation of hydrogel contact with a solid surface in water is indispensable for understanding the friction, lubrication, and adhesion of hydrogels under water. However, this is a difficult task since the refractive index of hydrogels is very close to that of water. In this paper, we present a novel method to in situ observe the macroscopic contact of hydrogels with a solid surface based on the principle of critical refraction. This method was applied to investigate the sliding friction of a polyacrylamide (PAAm) hydrogel with glass by using a strain-controlled parallel-plate rheometer. The study revealed that when the compressive pressure is not very high, the hydrogel forms a heterogeneous contact with the glass, and a macro-scale water drop is trapped at the soft interface. The pre-trapped water spreads over the interface to decrease the contact area with the increase in sliding velocity, which dramatically reduces the friction of the hydrogel. The study also revealed that this heterogeneous contact is the reason for the poor reproducibility of hydrogel friction that has been often observed in previous studies. Under the condition of homogeneous full contact, the molecular origin of hydrogel friction in water is discussed. This study highlights the importance of direct interfacial observation to reveal the friction mechanism of hydrogels.

  10. The creation of the artificial RING finger from the cross-brace zinc finger by α-helical region substitution

    International Nuclear Information System (INIS)

    Miyamoto, Kazuhide; Togiya, Kayo

    2010-01-01

    The creation of the artificial RING finger as ubiquitin-ligating enzyme (E3) has been demonstrated. In this study, by the α-helical region substitution between the EL5 RING finger and the Williams-Beuren syndrome transcription factor (WSTF) PHD finger, the artificial E3 (WSTF PHD R ING finger) was newly created. The experiments of the chemical modification of residues Cys and the circular dichroism spectra revealed that the WSTF PHD R ING finger binds two zinc atoms and adopts the zinc-dependent ordered-structure. In the substrate-independent ubiquitination assay, the WSTF PHD R ING finger functions as E3 and was poly- or mono-ubiquitinated. The present strategy is very simple and convenient, and consequently it might be widely applicable to the creation of various artificial E3 RING fingers with the specific ubiquitin-conjugating enzyme (E2)-binding capability.

  11. New Sliding Puzzle with Neighbors Swap Motion

    OpenAIRE

    Prihardono, Ariyanto; Kawagoe, Kenichi

    2015-01-01

    The sliding puzzles (15-puzzle, 8-puzzle, 5-puzzle) are known to have 2 kind of puz-zle: solvable puzzle and unsolvable puzzle. In this thesis, we make a new puzzle with only 1 kind of it, solvable puzzle. This new puzzle is made by adopting sliding puzzle with several additional rules from M13 puzzle; the puzzle that is formed form The Mathieu group M13. This puzzle has a movement that called a neighbors swap motion, a rule of movement that enables every neighboring points to swap. This extr...

  12. Tribological behaviors of graphite sliding against cemented carbide in CaCl2 solution

    International Nuclear Information System (INIS)

    Guo, Fei; Tian, Yu; Liu, Ying; Wang, Yuming

    2015-01-01

    The tribological behaviors of graphite sliding against cemented carbide were investigated using a standard tribological tester Plint TE92 in a ring-on-ring contact configuration in both CaCl 2 solution and deionized water. An interesting phenomenon occurred: as the CaCl 2 solution concentration increased, the friction coefficient firstly decreased and was lower than that in the deionized water, and then gradually increased, exceeding the friction coefficient in the deionized water. The wear rate of the ,graphite also presented the same variation trend. According to the polarization curves of cemented carbide, contact angle measurements, Raman spectrum analysis and scanning electron microscope (SEM) images analysis, the above friction and wear behaviors of graphite sliding against cemented carbide were attributed to the graphite surface wettability and the cemented carbide surface corrosion property. (paper)

  13. A fully rotational joint underactuated finger mechanism and its kinematics analysis

    Directory of Open Access Journals (Sweden)

    Wu Licheng

    2016-09-01

    Full Text Available The characteristic features of underactuated finger are compact structure, large grasping force, and simple operation. It has a wide application prospect in the fields of industrial robot, humanoid robot, human artificial limb, and space robot. A new type of fully rotating joint linkage-based underactuated mechanism is proposed, and a new method based on the law of minimum resistance is presented to realize the equivalent mechanism at different contact conditions of the finger and the kinematical analysis based on the equivalent mechanism. The kinematic equations and the limit moving position of the mechanism are derived using the proposed method. Finally, the numerical simulation is carried out by MATLAB program. The correctness and effectiveness of the proposed method are verified. The simulation results show that the proposed mechanism has a large grasp space and can achieve good grasp trajectory.

  14. Granular contact dynamics using mathematical programming methods

    DEFF Research Database (Denmark)

    Krabbenhoft, K.; Lyamin, A. V.; Huang, J.

    2012-01-01

    granular contact dynamics formulation uses an implicit time discretization, thus allowing for large time steps. Moreover, in the limit of an infinite time step, the general dynamic formulation reduces to a static formulation that is useful in simulating common quasi-static problems such as triaxial tests...... is developed and it is concluded that the associated sliding rule, in the context of granular contact dynamics, may be viewed as an artifact of the time discretization and that the use of an associated flow rule at the particle scale level generally is physically acceptable. (C) 2012 Elsevier Ltd. All rights...

  15. Interpretation of the Friction Coefficient During Reciprocating Sliding of Ti6Al4V Alloy Against Al2O3

    Directory of Open Access Journals (Sweden)

    S. Mitrovic

    2011-03-01

    Full Text Available Tribological behaviour of Ti6Al4V alloy, during linear reciprocating sliding against alumina, at nanotribometer (ball-on-flat type of contact was investigated. Experiments were carried out for sliding in Ringer's solution, over a range of loads (100 - 1000 mN and speeds (4 - 12 mm/s. Friction behaviour of the contact pairs was investigated by analysis of the dynamic friction coefficient plots and effective root mean square (rms coefficient of friction, COFrms. Presented mathematical envelopes of dynamic coefficient of friction curves and averaged envelope signals provided additional explanation of one calculated COFrms value. Envelopes of dynamic coefficient of friction enabled easier determination of different periods during sliding, which were further related to wear mechanisms.

  16. Prioritized Contact Transport Stream

    Science.gov (United States)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  17. VISIONS FOR FOOTWEAR TIP SHAPE ACCORDING TO THE CONFIGURATION FINGER

    Directory of Open Access Journals (Sweden)

    MALCOCI Marina

    2015-05-01

    Full Text Available Compatibility between the consumer and the interior leg permanent footwear raises a number of issues. And any new form of footwear is time for a new silhouette last. Fashion is a factor in determining the shape of the last significant role. The most important influence on fashion in footwear that has at one time is found in peak shape. During registered a variety of forms leading to the last, for example, pointed, oval, round, square, asymmetrical, curved, trapezoidal, etc. Each has added a tip top recommended. The paper analyzes the morphofunctional characteristic, namely, finger configuration. The configuration of the fingers is determined from the positions of all the fingers of one another, as are six variants. Analysis of the shape and configuration of the arm fingers allow us to make the following recommendations to consumers: people showing finger configuration as in variant V and VI are advised not to wear pointy shoes because of the limited movement of the foot, which favors the diversion finger I exterior and deformed finger V; persons who fall within I-IV variant can procure pointy shoes; a round-tipped shoes, square, curved or asymmetric may be purchased by any consumer regardless of the configuration of the fingers; shoes with cut edge must be present only in garderopa people in variant I and II; consumers whose configuration is like finger-VI and III variants are awkwardly shaped fingers can buy shoes closed in the previous summer, but of different perforations or overlapping strips.

  18. Speed invariance of independent control of finger movements in pianists.

    Science.gov (United States)

    Furuya, Shinichi; Soechting, John F

    2012-10-01

    Independent control of finger movements characterizes skilled motor behaviors such as tool use and musical performance. The purpose of the present study was to identify the effect of movement frequency (tempo) on individuated finger movements in piano playing. Joint motion at the digits was recorded while 5 expert pianists were playing 30 excerpts from musical pieces with different fingering and key locations either at a predetermined normal tempo or as fast as possible. Principal component analysis and cluster analysis using an expectation-maximization algorithm determined three distinct patterns of finger movement coordination for a keypress with each of the index, middle, ring, and little fingers at each of the two tempi. The finger kinematics of each coordination pattern was overall similar across the tempi. Tone sequences assigned into each cluster were also similar for both tempi. A linear regression analysis determined no apparent difference in the amount of movement covariation between the striking and nonstriking fingers at both metacarpo-phalangeal and proximal-interphalangeal joints across the two tempi, which indicated no effect of tempo on independent finger movements in piano playing. In addition, the standard deviation of interkeystroke interval across strokes did not differ between the two tempi, indicating maintenance of rhythmic accuracy of keystrokes. Strong temporal constraints on finger movements during piano playing may underlie the maintained independent control of fingers over a wider range of tempi, a feature being likely to be specific to skilled pianists.

  19. The role of fingers in number processing in young children.

    Science.gov (United States)

    Lafay, Anne; Thevenot, Catherine; Castel, Caroline; Fayol, Michel

    2013-01-01

    The aim of the present study was to investigate the relationship between finger counting and numerical processing in 4-7-year-old children. Children were assessed on a variety of numerical tasks and we examined the correlations between their rates of success and their frequency of finger use in a counting task. We showed that children's performance on finger pattern comparison and identification tasks did not correlate with the frequency of finger use. However, this last variable correlated with the percentages of correct responses in an enumeration task (i.e., Give-N task), even when the age of children was entered as a covariate in the analysis. Despite this correlation, we showed that some children who never used their fingers in the counting task were able to perform optimally in the enumeration task. Overall, our results support the conclusion that finger counting is useful but not necessary to develop accurate symbolic numerical skills. Moreover, our results suggest that the use of fingers in a counting task is related to the ability of children in a dynamic enumeration task but not to static tasks involving recognition or comparison of finger patterns. Therefore, it could be that the link between fingers and numbers remain circumscribed to counting tasks and do not extent to static finger montring situations.

  20. The role of fingers in number processing in young children

    Directory of Open Access Journals (Sweden)

    Anne eLafay

    2013-07-01

    Full Text Available The aim of the present study was to investigate the relationship between finger counting and numerical processing in 4- to 7-year-old children. Children were assessed on a variety of numerical tasks and we examined the correlations between their rates of success and their frequency of finger use in a counting task. We showed that children’s performance on finger pattern comparison and identification tasks did not correlate with the frequency of finger use. However, this last variable correlated with the percentages of correct responses in an enumeration task (i.e., Give-N task, even when the age of children was entered as a covariate in the analysis. Despite this correlation, we showed that some children who never used their fingers in the counting task were able to perform optimally in the enumeration task. Overall, our results support the conclusion that finger counting is useful but not necessary to develop accurate symbolic numerical skills. Moreover, our results suggest that the use of fingers in a counting task is related to the ability of children in a dynamic enumeration task but not to static tasks involving recognition or comparison of finger patterns. Therefore, it could be that the link between fingers and numbers remain circumscribed to counting tasks and do not extent to static finger montring situations.

  1. Application of x-ray diffraction techniques to the understanding of the dry sliding wear behaviour of aluminium and titanium

    International Nuclear Information System (INIS)

    Zoheir, N.; Ahmet, T.A.; Northwood, D.O.

    1996-01-01

    Dry sliding wear tests were performed on polycrystalline f.c.c. Al and h.c.p. Ti specimens using a block-on-ring type wear machine with a rotating ring made of 52100 bearing steel. The sliding speed was 0.13 m.s sup -l and the applied normal load was 10 N. The wear tests were performed on a single specimen in ambient conditions and the texture was evaluated during wear using an X-ray diffraction inverse pole figure technique at a range of sliding distances. Pole density distributions for the [0001] and [111) poles for of Ti and Al, respectively, were then determined from the inverse pole figures. The texture evolution during sliding wear was subsequently related to the friction and wear behaviour. For the aluminum sample, a (111) texture developed parallel to the worn surface with increasing sliding distance (a 6 fold increase in the (111) pole density as the sliding distance increases from 0 to 2714 m). The titanium sample (normal section) which had a preferred orientation with the basal poles, [0001), parallel to the contact surface prior to testing, an increase in wear, i.e. sliding distance, did not change the texture. However, for the transverse section of titanium, the basal pole, [0001), density parallel to the worn surface increased with increasing sliding distance. The shape of the coefficient of friction versus sliding distance curve is strongly influenced by crystallographic texturing. A drop in the coefficient of friction with the progressive development of the [111) and [0001) texture was observed for both Al and Ti (transverse section) specimens, respectively

  2. ARC discharge sliding over a conducting surface

    NARCIS (Netherlands)

    van Goor, F.A.; Mitko, S.; Ochkin, V.N.; Paramonov, A.P.; Witteman, W.J.

    1997-01-01

    Results of experimental and theoretical studies of the arc discharge which slides over the surface of a conductor are reported. Experiments were performed in air and argon ambients at various pressures. It is found that the velocity of the discharge plasma front depends linearly on the strength of

  3. Impact Driver With Integral Sliding Hammer

    Science.gov (United States)

    Wallace, Bilby J.

    1987-01-01

    Tool combines impact driver with sliding dead-blow hammer. Used for any purpose for which ordinary impact driver used; tightening fasteners or driving starter holes for drill. Tool protects user from accidental injury and surrounding equipment from damage that might occur from ordinary arm-wielded hammer. Especially useful in underwater work.

  4. A thermodynamic model of sliding friction

    Directory of Open Access Journals (Sweden)

    Lasse Makkonen

    2012-03-01

    Full Text Available A first principles thermodynamic model of sliding friction is derived. The model predictions are in agreement with the observed friction laws both in macro- and nanoscale. When applied to calculating the friction coefficient the model provides a quantitative agreement with recent atomic force microscopy measurements on a number of materials.

  5. SCHISTOSOMAL APPENDICITIS IN A SLIDING HERNIA (CASE ...

    African Journals Online (AJOL)

    We report a rare case of a forty-seven year old Nigeria male with schistosomal appendicitis in a sliding hernia. The clinical and pathological features of the case are discussed, followed by a review of the literature. It is concluded that a high index of suspicion is necessary to diagnose unusual presentations of ...

  6. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

    Ruol, Piero; Martin, Paolo; Andersen, Thomas Lykke

    2014-01-01

    This note presents wave flume experiments, carried out at Aalborg University, measuring the horizontal sliding distance of a vertical breakwater in 1:40 scale. Horizontal and uplift wave induced pressures were accurately measured simultaneously with the caisson movements. Caissons of different...

  7. WWNPQFT-2010 - Slides of the presentations

    International Nuclear Information System (INIS)

    Fried, H.M.; Huber, M.Q.; Grandou, T.; Bianchi, E.; Gracey, J.; Reys, V.; Jevicki, A.; Ferrante, D.; Bouakaz, K.; Spielmann, D.; Cucchieri, A.; Culetu, H.; Gelis, F.; Zwanziger, D.; Candelpergher, B.; Bender, C.

    2013-01-01

    This document is made up of the slides of the presentations. The object of this workshop is to consolidate and publicize new efforts in non-perturbative field theories. The main topics are quantum chromodynamics, Yang-Mills theory, effective locality, the Gribov-Zwanziger Lagrangian, and renormalization. A presentation is dedicated to the initial stages of high energy nucleus-nucleus collisions

  8. TARG2 Workshop - Slides of the presentations

    International Nuclear Information System (INIS)

    Malka, V.; Koehler, A.; Beaurepaire, B.; Krishnan, M.; Guillaume, E.; Chowdhury, E.; Volpe, L.; Nakatsutsumi, M.; Chatain, D.; Legare, F.; Wachulak, P.; Bocoum, M.; Leblanc, A.; Schreiber, J.; Ter-Avetisyan, S.; Zeil, K.; Fukuda, Y.; Levecq, X.; Svensson, K.; Mollica, F.; Brandi, F.; Ruiz, C.

    2016-01-01

    The topics tackled in this workshop involved: laser-plasma interaction, innovative targets from gases to solids, targetry recycling and debris management, mass fabrication of laser targets, high repetition rate capability, integrated plasma diagnostics, wakefield acceleration and radiation sources. This document is made up of the slides of the presentations

  9. Torque Control of Underactuated Tendon-driven Robotic Fingers

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  10. Finger agnosia and cognitive deficits in patients with Alzheimer's disease.

    Science.gov (United States)

    Davis, Andrew S; Trotter, Jeffrey S; Hertza, Jeremy; Bell, Christopher D; Dean, Raymond S

    2012-01-01

    The purpose of this study was to examine the presence of finger agnosia in patients with Alzheimer's disease (AD) and to determine if level of finger agnosia was related to cognitive impairment. Finger agnosia is a sensitive measure of cerebral impairment and is associated with neurofunctional areas implicated in AD. Using a standardized and norm-referenced approach, results indicated that patients with AD evidenced significantly decreased performance on tests of bilateral finger agnosia compared with healthy age-matched controls. Finger agnosia was predictive of cognitive dysfunction on four of seven domains, including: Crystallized Language, Fluid Processing, Associative Learning, and Processing Speed. Results suggest that measures of finger agnosia, a short and simple test, may be useful in the early detection of AD.

  11. Erosion waves: Transverse instabilities and fingering

    Science.gov (United States)

    Malloggi, F.; Lanuza, J.; Andreotti, B.; Clément, E.

    2006-09-01

    Two laboratory scale experiments of dry and underwater avalanches of non-cohesive granular materials are investigated. We trigger solitary waves and study the conditions under which the front is transversally stable. We show the existence of a linear instability followed by a coarsening dynamics and finally the onset of a fingering pattern. Due to the different operating conditions, both experiments strongly differ by the spatial and time scales involved. Nevertheless, the quantitative agreement between the stability diagram, the wavelengths selected and the avalanche morphology suggest a common scenario for an erosion/deposition process.

  12. Radiofrequency contact currents: sensory responses and dosimetry

    International Nuclear Information System (INIS)

    Kavet, Robert; Tell, R.A.; Olsen, R.G.

    2014-01-01

    The process of setting science-based exposure standards (or guidelines) for radiofrequency (RF) contact current exposure has been disadvantaged by a lack of relevant data. The authors first review the essential features and results of the available studies and illustrate the apparent discrepancies among them. Then, they examine the manner in which current was administered in these studies and suggest as to how the physical relationship of a contacting finger to the current electrode may play a role in affecting sensory thresholds specific to those configurations. A major factor in this analysis relates to whether current density is uniformly distributed across the contact area or whether an electrode's 'edge effects' enhance currents with a net effect of decreasing apparent thresholds, when expressed as the bulk current entering a subject. For an exposure with a clear hazard potential, thresholds of human sensory response to RF currents require further investigation. (authors)

  13. Sliding Mode Control of Induction Motor Phase Currents

    DEFF Research Database (Denmark)

    Hansen, R.B.; Hattel, T.; Bork, J

    1995-01-01

    Sliding mode control of induction motor phase currents are investigated through development of two control concepts.......Sliding mode control of induction motor phase currents are investigated through development of two control concepts....

  14. Applications of sliding mode control in science and engineering

    CERN Document Server

    Lien, Chang-Hua

    2017-01-01

    Gathering 20 chapters contributed by respected experts, this book reports on the latest advances in and applications of sliding mode control in science and engineering. The respective chapters address applications of sliding mode control in the broad areas of chaos theory, robotics, electrical engineering, physics, chemical engineering, memristors, mechanical engineering, environmental engineering, finance, and biology. Special emphasis has been given to papers that offer practical solutions, and which examine design and modeling involving new types of sliding mode control such as higher order sliding mode control, terminal sliding mode control, super-twisting sliding mode control, and integral sliding mode control. This book serves as a unique reference guide to sliding mode control and its recent applications for graduate students and researchers with a basic knowledge of electrical and control systems engineering.

  15. Vertical Finger Displacement Is Reduced in Index Finger Tapping During Repeated Bout Rate Enhancement.

    Science.gov (United States)

    Mora-Jensen, Mark Holten; Madeleine, Pascal; Hansen, Ernst Albin

    2017-10-01

    The present study analyzed (a) whether a recently reported phenomenon of repeated bout rate enhancement in finger tapping (i.e., a cumulating increase in freely chosen finger tapping frequency following submaximal muscle activation in the form of externally unloaded voluntary tapping) could be replicated and (b) the hypotheses that the faster tapping was accompanied by changed vertical displacement of the fingertip and changed peak force during tapping. Right-handed, healthy, and recreationally active individuals (n = 24) performed two 3-min index finger tapping bouts at freely chosen tapping frequency, separated by 10-min rest. The recently reported phenomenon of repeated bout rate enhancement was replicated. The faster tapping (8.8 ± 18.7 taps/min, corresponding to 6.0 ± 11.0%, p = .033) was accompanied by reduced vertical displacement (1.6 ± 2.9 mm, corresponding to 6.3 ± 14.9%, p = .012) of the fingertip. Concurrently, peak force was unchanged. The present study points at separate control mechanisms governing kinematics and kinetics during finger tapping.

  16. Extrinsic versus intrinsic hand muscle dominance in finger flexion.

    Science.gov (United States)

    Al-Sukaini, A; Singh, H P; Dias, J J

    2016-05-01

    This study aims to identify the patterns of dominance of extrinsic or intrinsic muscles in finger flexion during initiation of finger curl and mid-finger flexion. We recorded 82 hands of healthy individuals (18-74 years) while flexing their fingers and tracked the finger joint angles of the little finger using video motion tracking. A total of 57 hands (69.5%) were classified as extrinsic dominant, where the finger flexion was initiated and maintained at proximal interphalangeal and distal interphalangeal joints. A total of 25 (30.5%) were classified as intrinsic dominant, where the finger flexion was initiated and maintained at the metacarpophalangeal joint. The distribution of age, sex, dominance, handedness and body mass index was similar in the two groups. This knowledge may allow clinicians to develop more efficient rehabilitation regimes, since intrinsic dominant individuals would not initiate extrinsic muscle contraction till later in finger flexion, and might therefore be allowed limited early active motion. For extrinsic dominant individuals, by contrast, initial contraction of extrinsic muscles would place increased stress on the tendon repair site if early motion were permitted. © The Author(s) 2016.

  17. Tetanus following replantation of an amputated finger: a case report.

    Science.gov (United States)

    Hayashida, Kenji; Murakami, Chikako; Fujioka, Masaki

    2012-10-08

    Tetanus is an infectious disease caused by tetanus toxin produced by Clostridium tetani and induces severe neurological manifestations. We treated a patient who developed tetanus during hospitalization for replantation of an amputated finger. To the best of our knowledge, this is the first published case report of such an entity. A 49-year-old Japanese man had an amputation of his right middle finger at the distal interphalangeal joint region in an accident at work. His middle finger was successfully replanted, but his fingertip was partially necrotized because of crushing and so additional reconstruction with a reverse digital arterial flap was performed 15 days after the injury. Tetanus developed 21 days after replantation of the middle finger, but symptoms remitted via rapid diagnosis and treatment. In replantation after finger trauma with exposure of nerve and blood vessel bundles, concern over injuring nerves and blood vessels may prevent irrigation and debridement from being performed sufficiently; these treatments may have been insufficiently performed in this patient. It is likely that the replanted middle finger partially adhered, and Clostridium tetani colonized the partially necrotized region. Even when there is only limited soil contamination, administration of tetanus toxoid and anti-tetanus immunoglobulin is necessary when the fingers are injured outdoors and the finger nerves and blood vessels are exposed. The drugs should be administered just after replantation if the finger has been amputated. However, if clinicians pay attention to the possibility of tetanus development, treatment can be rapidly initiated.

  18. Tetanus following replantation of an amputated finger: a case report

    Directory of Open Access Journals (Sweden)

    Hayashida Kenji

    2012-10-01

    Full Text Available Abstract Introduction Tetanus is an infectious disease caused by tetanus toxin produced by Clostridium tetani and induces severe neurological manifestations. We treated a patient who developed tetanus during hospitalization for replantation of an amputated finger. To the best of our knowledge, this is the first published case report of such an entity. Case presentation A 49-year-old Japanese man had an amputation of his right middle finger at the distal interphalangeal joint region in an accident at work. His middle finger was successfully replanted, but his fingertip was partially necrotized because of crushing and so additional reconstruction with a reverse digital arterial flap was performed 15 days after the injury. Tetanus developed 21 days after replantation of the middle finger, but symptoms remitted via rapid diagnosis and treatment. Conclusions In replantation after finger trauma with exposure of nerve and blood vessel bundles, concern over injuring nerves and blood vessels may prevent irrigation and debridement from being performed sufficiently; these treatments may have been insufficiently performed in this patient. It is likely that the replanted middle finger partially adhered, and Clostridium tetani colonized the partially necrotized region. Even when there is only limited soil contamination, administration of tetanus toxoid and anti-tetanus immunoglobulin is necessary when the fingers are injured outdoors and the finger nerves and blood vessels are exposed. The drugs should be administered just after replantation if the finger has been amputated. However, if clinicians pay attention to the possibility of tetanus development, treatment can be rapidly initiated.

  19. EPR spectroscopic investigation of psoriatic finger nails.

    Science.gov (United States)

    Nakagawa, Kouichi; Minakawa, Satoko; Sawamura, Daisuke

    2013-11-01

    Nail lesions are common features of psoriasis and found in almost half of the patients. However, there is no feasible spectroscopic method evaluating changes and severity of nail psoriasis. EPR (electron paramagnetic resonance) might be feasible for evaluating nail conditions in the patients of psoriasis. Finger nails of five cases with nail psoriasis, (three females and two males) were examined. Nail samples were subjected to the EPR assay. The small piece of the finger nail (1.5 × 5 mm(2)) was incubated in ~50 μM 5-DSA (5-doxylstearic acid) aqueous solutions for about 60 min at 37°C. After rinsing and wiping off the excess 5-DSA solution, the nail samples were measured by EPR. EPR spectra were analyzed using the intensity ratio (Fast/Slow) of the two motions at the peaks of the lower magnetic field. We observed two distinguishable sites on the basis of the EPR results. In addition, the modern EPR calculation was performed to analyze the spectra obtained. The nail psoriasis-related region is 2~3 times higher than that of the control. The present EPR results show that there are two distinguishable sites in the nail. In the case of nail psoriasis, the fragile components are 2~3 times more than those of the control. Thus, the EPR method is thought to be a novel and reliable method of evaluating the nail psoriasis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Oxidation-Mediated Fingering in Liquid Metals

    Science.gov (United States)

    Eaker, Collin B.; Hight, David C.; O'Regan, John D.; Dickey, Michael D.; Daniels, Karen E.

    2017-10-01

    We identify and characterize a new class of fingering instabilities in liquid metals; these instabilities are unexpected due to the large interfacial tension of metals. Electrochemical oxidation lowers the effective interfacial tension of a gallium-based liquid metal alloy to values approaching zero, thereby inducing drastic shape changes, including the formation of fractals. The measured fractal dimension (D =1.3 ±0.05 ) places the instability in a different universality class than other fingering instabilities. By characterizing changes in morphology and dynamics as a function of droplet volume and applied electric potential, we identify the three main forces involved in this process: interfacial tension, gravity, and oxidative stress. Importantly, we find that electrochemical oxidation can generate compressive interfacial forces that oppose the tensile forces at a liquid interface. The surface oxide layer ultimately provides a physical and electrochemical barrier that halts the instabilities at larger positive potentials. Controlling the competition between interfacial tension and oxidative (compressive) stresses at the interface is important for the development of reconfigurable electronic, electromagnetic, and optical devices that take advantage of the metallic properties of liquid metals.

  1. Teleoperation of Robonaut Using Finger Tracking

    Science.gov (United States)

    Champoux, Rachel G.; Luo, Victor

    2012-01-01

    With the advent of new finger tracking systems, the idea of a more expressive and intuitive user interface is being explored and implemented. One practical application for this new kind of interface is that of teleoperating a robot. For humanoid robots, a finger tracking interface is required due to the level of complexity in a human-like hand, where a joystick isn't accurate. Moreover, for some tasks, using one's own hands allows the user to communicate their intentions more effectively than other input. The purpose of this project was to develop a natural user interface for someone to teleoperate a robot that is elsewhere. Specifically, this was designed to control Robonaut on the international space station to do tasks too dangerous and/or too trivial for human astronauts. This interface was developed by integrating and modifying 3Gear's software, which includes a library of gestures and the ability to track hands. The end result is an interface in which the user can manipulate objects in real time in the user interface. then, the information is relayed to a simulator, the stand in for Robonaut, at a slight delay.

  2. Atomistic Simulation of Frictional Sliding Between Cellulose Iß Nanocrystals

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2013-01-01

    Sliding friction between cellulose Iß nanocrystals is studied using molecular dynamics simulation. The effects of sliding velocity, normal load, and relative angle between sliding surface are predicted, and the results analyzed in terms of the number of hydrogen bonds within and between the cellulose chains. We find that although the observed friction trends can be...

  3. the strategy of finger use in children's addition Relationship with short-term memory, finger dexterity, and addition skills

    OpenAIRE

    Asakawa, Atsushi; Sugimura, Shinichiro

    2009-01-01

    Previous research has shown that the children's use of the fingers in additon changes with age. In this study, a part of data on the strategy of finger use by Asakawa and Sugimura (2009) was reanalyzed to clarify the relationship between, short-term memory, finger dexterity and addition skills. A two-way ANOVA showed a significant interaction between memory span and finger use. Examination of simple main effect indicated that significant effect of memory span at the group of the children who ...

  4. Finger-like voids induced by viscous fingering during phase inversion of alumina/PES/NMP suspensions

    KAUST Repository

    Wang, Bo

    2012-07-01

    The formation mechanism of phase-inversion ceramic hollow fibre membranes has not been well understood. In this paper, we report on the formation of finger-like macrovoids during non-solvent-induced phase inversion of alumina/PES/NMP suspensions. A membrane structure without such finger-like macrovoids was observed when the suspension was slowly immersed into pure ethanol or a mixture of 70. wt% NMP and 30. wt% water, whereas finger-like macrovoids occurred when the suspension was slid into the non-solvents at higher speeds. We found that the formation process of finger-like macrovoids could be fully or partially reversed when nascent membranes were taken out from water shortly after immersion, depending on the duration of the immersion. Splitting of the fingers during the formation of the macrovoids was also observed during the phase inversion of two alumina/PES/NMP suspensions. These experimental observations were not predicted by current theories of finger-like macrovoid formation in polymer membranes, but appear to mimic the well-known viscous fingering phenomenon. We therefore propose that in the phase inversion of ceramic suspensions, the viscous fingering phenomenon is an important mechanism in the formation of finger-like voids. © 2012 Elsevier B.V.

  5. Power-assistive finger exoskeleton with a palmar opening at the fingerpad.

    Science.gov (United States)

    Heo, Pilwon; Kim, Jung

    2014-11-01

    This paper presents a powered finger exoskeleton with an open fingerpad, named the Open Fingerpad eXoskeleton (OFX). The palmar opening at the fingerpad allows for direct contact between the user's fingerpad and objects in order to make use of the wearer's own tactile sensation for dexterous manipulation. Lateral side walls at the end of the OFX's index finger module are equipped with custom load cells for estimating the wearer's pinch grip force. A pneumatic cylinder generates assistance force, which is determined according to the estimated pinch grip force. The OFX transmits the assistance force directly to the objects without exerting pressure on the wearer's finger. The advantage of the OFX over an exoskeleton with a closed fingerpad was validated experimentally. During static and dynamic manipulation of a test object, the OFX exhibited a lower safety margin than the closed exoskeleton, indicating a higher ability to adjust the grip force within an appropriate range. Furthermore, the benefit of force assistance in reducing the muscular burden was observed in terms of muscle fatigue during a static pinch grip. The median frequency (MDF) of the surface electromyography (sEMG) signal from the first dorsal interosseous (FDI) muscle displayed a lower reduction rate for the assisted condition, indicating a lower accumulation rate of muscle fatigue.

  6. Contact Lens Care

    Science.gov (United States)

    ... Consumers Consumer Information by Audience For Women Contact Lens Care Share Tweet Linkedin Pin it More sharing ... www.fda.gov/medwatch Learn More about Contact Lens Care Other Tips on Contact Lenses Decorative Contact ...

  7. Virtual slides: application in pulmonary pathology consultations.

    Directory of Open Access Journals (Sweden)

    Michał Wojciechowski

    2008-02-01

    Full Text Available The Virtual Slide (VS is an interactive microscope emulator that presents a complete digitized tissue section via the Internet. A successful implementation of VS has been observed for educational, research venues and quality control. VS acquisition for consultative pathology is not so common. The purpose of this study was to explore the efficacy and usability of VS in the consultative pulmonary telepathology. 20 lung tumors entered the study. The performance was programmed for 2 medical centers specialized in pulmonary pathology (beginner and advancer in telepathology. A high-quality VSs were prepared by Coolscope (Nikon, Eclipsnet VSL, Japan, and were evaluated via the Internet. The cases were reviewed for the second time with conventional light microscope. VS diagnostic accuracy and the interobserver variability were evaluated. Also the time taken by examiners to render the diagnoses and time needed to scan the microscopic slide were analyzed. Percentage concordance between original glass-slides diagnosis and diagnosis for VSs was very high. Pathologists found the download speed of VSs adequate; experience in telepathology reduced the time of VS diagnosis. VS implementation suggests advantages for teleconsulation and education but also indicate some technical limitations. This is the first Polish trial of VS implementation in telepathology consultative service.

  8. Skin cooling on contact with cold materials: the effect of blood flow during short-term exposures.

    Science.gov (United States)

    Jay, Ollie; Havenith, George

    2004-03-01

    This study investigates the effect of blood flow upon the short-term (cooling response in order to ascertain whether sufferers of circulatory disorders, such as the vasospastic disorder Raynaud's disease, are at a greater risk of cold injury than people with a normal rate of blood flow. Eight female volunteers participated, touching blocks of stainless steel and nylon with a finger contact force of 2.9 N at a surface temperature of -5 degrees C under occluded and vasodilated conditions. Contact temperature (Tc) of the finger pad was measured over time using a T-type thermocouple. Forearm blood flow was measured using strain gauge plethysmography. Contact cooling responses were analysed by fitting a modified Newtonian cooling curve. A significant difference was found between the starting skin temperatures for the two blood flow conditions (Peffect of blood flow was found upon any of the derived cooling curve parameters characterizing the skin cooling response (P>0.05). It is hypothesized that the finger contact force used (2.9 N) and the resultant pressure upon the tissue of the contact finger pad restricted the blood supply to the contact area under both blood flow conditions; therefore, no effect of blood flow was found upon the parameters describing the contact cooling response. Whilst the findings of this study are sufficient to draw a conclusion for those in a working environment, i.e. contact forces below 2.9 N will seldom be encountered, a further study will be required to ascertain conclusively whether blood flow does affect the contact cooling response at a finger contact force low enough to allow unrestricted blood flow to the finger pad. Further protocol improvements are also recommended.

  9. Tactile Sliding Behavior of R2R Mass-Produced PLLA Nanosheet towards Biomedical Device in Skin Applications

    Directory of Open Access Journals (Sweden)

    Sheng Zhang

    2018-03-01

    Full Text Available In this research, sliding friction was measured between the fingertip and nanosheet on a silicon substrate under two conditions: dry and wet. By using a force transducer, the tactile friction force and applied load were measured. According to the experimental results, the relationship of friction force and applied load exhibits a positive correlation under both dry and wet conditions. In addition, the nanosheets are able to reduce the friction force and coefficient of friction (COF compared to the reference sample, especially under the wet condition. Under the assumption of a full contact condition, the estimated contact area increases with larger applied loads. Furthermore, based on the wear observation, the skin sliding performance caused slight abrasions to the surface of the nanosheet samples with a mild wear track along the sliding direction. Overall, the sliding behavior between the skin and nanosheet was investigated in terms of friction force, COF, applied load, contact area, and wear. These findings can contribute to the nanosheet-related research towards biomedical devices in skin applications.

  10. Seismic behavior with sliding of overhead travelling crane

    International Nuclear Information System (INIS)

    Komori, Akio; Ueki, Takashi; Hirata, Masami; Hoshii, Tsutomu; Kashiwazaki, Akihiro.

    1989-01-01

    In this study, the seismic behavior of an overhead travelling crane with the sliding between travelling wheels and rails is examined. First, the dynamic characteristic test of the actual crane installed in a reactor building and the sliding test of the rigid-element model to observe the basic sliding characteristic were performed. Next, to examine the dynamic response with sliding, shaking tests using the scaled model of an actual crane were conducted. From these results, useful design information about seismic behavior of an overhead travelling crane was obtained. It was also observed that numerical predictions considering sliding behavior have good agreement with the experimental results and are applicable to seismic design. (author)

  11. Evaluation of the finger wrinkling test: A pilot study

    NARCIS (Netherlands)

    van Barneveld, S.; van der Palen, Jacobus Adrianus Maria; van Putten, Michel Johannes Antonius Maria

    2010-01-01

    Purpose: Tilt table testing mainly evaluates the systemic cardiovascular part of the autonomic nervous system, while it is assumed that the finger wrinkling test assesses the peripheral part of the autonomic nervous system. In this study we explored whether the finger wrinkling test could be a

  12. Automated Finger Spelling by Highly Realistic 3D Animation

    Science.gov (United States)

    Adamo-Villani, Nicoletta; Beni, Gerardo

    2004-01-01

    We present the design of a new 3D animation tool for self-teaching (signing and reading) finger spelling the first basic component in learning any sign language. We have designed a highly realistic hand with natural animation of the finger motions. Smoothness of motion (in real time) is achieved via programmable blending of animation segments. The…

  13. Population Structure and Diversity in Finger Millet (Eleusine coracana) Germplasm.

    Science.gov (United States)

    A genotypic analysis of 79 finger millet accessions (E. coracana subsp. coracana) from 11 African and 5 Asian countries, plus 14 wild E. coracana subsp. africana lines collected in Uganda and Kenya was conducted with 45 SSR markers distributed across the finger millet genome. Phylogenetic and popula...

  14. Quantitative assessment of finger motor performance: Normative data.

    Directory of Open Access Journals (Sweden)

    Alessio Signori

    Full Text Available Finger opposition movements are the basis of many daily living activities and are essential in general for manipulating objects; an engineered glove quantitatively assessing motor performance during sequences of finger opposition movements has been shown to be useful to provide reliable measures of finger motor impairment, even subtle, in subjects affected by neurological diseases. However, the obtained behavioral parameters lack published reference values.To determine mean values for different motor behavioral parameters describing the strategy adopted by healthy people in performing repeated sequences of finger opposition movements, examining associations with gender and age.Normative values for finger motor performance parameters were obtained on a sample of 255 healthy volunteers executing sequences of finger-to-thumb opposition movements, stratified by gender and over a wide range of ages. Touch duration, inter-tapping interval, movement rate, correct sequences (%, movements in advance compared with a metronome (% and inter-hand interval were assessed.Increasing age resulted in decreased movement speed, advance movements with respect to a cue, correctness of sequences, and bimanual coordination. No significant performance differences were found between male and female subjects except for the duration of the finger touch, the interval between two successive touches and their ratio.We report age- and gender-specific normal mean values and ranges for different parameters objectively describing the performance of finger opposition movement sequences, which may serve as useful references for clinicians to identify possible deficits in subjects affected by diseases altering fine hand motor skills.

  15. Experience of Percutaneous Trigger Finger Release under Local ...

    African Journals Online (AJOL)

    Background: Trigger finger is a common disorder of upper extremity. Majority of the patients can be treated conservatively but some resistant cases eventually need surgery. Aim: The aim of this study is to evaluate the results of percutaneous trigger finger release under local anesthesia. Subjects and Methods: This is a ...

  16. Robust finger vein ROI localization based on flexible segmentation.

    Science.gov (United States)

    Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

    2013-10-24

    Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

  17. Robust Finger Vein ROI Localization Based on Flexible Segmentation

    Directory of Open Access Journals (Sweden)

    Dong Sun Park

    2013-10-01

    Full Text Available Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

  18. Finger vein extraction using gradient normalization and principal curvature

    Science.gov (United States)

    Choi, Joon Hwan; Song, Wonseok; Kim, Taejeong; Lee, Seung-Rae; Kim, Hee Chan

    2009-02-01

    Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction method which is composed of gradient normalization, principal curvature calculation, and binarization. As local brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our experiment, the proposed method showed notable improvement as compared with the existing methods.

  19. Robust Finger Vein ROI Localization Based on Flexible Segmentation

    Science.gov (United States)

    Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

    2013-01-01

    Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system. PMID:24284769

  20. Feasibility of ambulatory, continuous 24-hour finger arterial pressure recording

    NARCIS (Netherlands)

    Imholz, B. P.; Langewouters, G. J.; van Montfrans, G. A.; Parati, G.; van Goudoever, J.; Wesseling, K. H.; Wieling, W.; Mancia, G.

    1993-01-01

    We tested Portapres, an innovative portable, battery-operated device for the continuous, noninvasive, 24-hour ambulatory measurement of blood pressure in the finger. Portapres is based on Finapres, a stationary device for the measurement of finger arterial pressure. Systems were added to record

  1. Finger impedance evaluation by means of hand exoskeleton.

    Science.gov (United States)

    Fiorilla, Angelo Emanuele; Nori, Francesco; Masia, Lorenzo; Sandini, Giulio

    2011-12-01

    Modulation of arm mechanical impedance is a fundamental aspect for interaction with the external environment and its regulation is essential for stability preservation during manipulation. Even though past research on human arm movements has suggested that models of human finger impedance would benefit the study of neural control mechanisms and the design of novel hand prostheses, relatively few studies have focused on finger and hand impedance. This article touches on the two main aspects of this research topic: first it introduces a mechanical refinement of a device that can be used to effectively measure finger impedance during manipulation tasks; then, it describes a pilot study aimed at identifying the inertia of the finger and the viscous and elastic properties of finger muscles. The proposed wearable exoskeleton, which has been designed to measure finger posture and impedance modulation while leaving the palm free, is capable of applying fast displacements while monitoring the interaction forces between the human finger and the robotic links. Moreover, due to the relatively small inertia of the fingers, it allows us to meet some stringent specifications, performing relatively large displacements (~45°) before the stretch reflex intervenes (~25 ms). The results of measurements on five subjects show that inertia, damping, and stiffness can be effectively identified and that the parameters obtained are comparable with values from previous studies.

  2. Number magnitude to finger mapping is disembodied and topological.

    Science.gov (United States)

    Plaisier, Myrthe A; Smeets, Jeroen B J

    2011-03-01

    It has been shown that humans associate fingers with numbers because finger counting strategies interact with numerical judgements. At the same time, there is evidence that there is a relation between number magnitude and space as small to large numbers seem to be represented from left to right. In the present study, we investigated whether number magnitude to finger mapping is embodied (related to the order of fingers on the hand) or disembodied (spatial). We let healthy human volunteers name random numbers between 1 and 30, while simultaneously tapping a random finger. Either the hands were placed directly next to each other, 30 cm apart, or the hands were crossed such that the left hand was on the right side of the body mid-line. The results show that naming a smaller number than the previous one was associated with tapping a finger to the left of the previously tapped finger. This shows that there is a spatial (disembodied) mapping between number magnitude and fingers. Furthermore, we show that this mapping is topological rather than metrically scaled.

  3. Sulfur passivation and contact methods for GaAs nanowire solar cells

    International Nuclear Information System (INIS)

    Tajik, N; Peng, Z; Kuyanov, P; LaPierre, R R

    2011-01-01

    The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements.

  4. Adaptive Sliding Mode Control Method Based on Nonlinear Integral Sliding Surface for Agricultural Vehicle Steering Control

    Directory of Open Access Journals (Sweden)

    Taochang Li

    2014-01-01

    Full Text Available Automatic steering control is the key factor and essential condition in the realization of the automatic navigation control of agricultural vehicles. In order to get satisfactory steering control performance, an adaptive sliding mode control method based on a nonlinear integral sliding surface is proposed in this paper for agricultural vehicle steering control. First, the vehicle steering system is modeled as a second-order mathematic model; the system uncertainties and unmodeled dynamics as well as the external disturbances are regarded as the equivalent disturbances satisfying a certain boundary. Second, a transient process of the desired system response is constructed in each navigation control period. Based on the transient process, a nonlinear integral sliding surface is designed. Then the corresponding sliding mode control law is proposed to guarantee the fast response characteristics with no overshoot in the closed-loop steering control system. Meanwhile, the switching gain of sliding mode control is adaptively adjusted to alleviate the control input chattering by using the fuzzy control method. Finally, the effectiveness and the superiority of the proposed method are verified by a series of simulation and actual steering control experiments.

  5. Finger pressure adjustments to various object configurations during precision grip in humans and monkeys.

    Science.gov (United States)

    Viaro, Riccardo; Tia, Banty; Coudé, Gino; Canto, Rosario; Oliynyk, Andriy; Salmas, Paola; Masia, Lorenzo; Sandini, Giulio; Fadiga, Luciano

    2017-06-01

    In this study, we recorded the pressure exerted onto an object by the index finger and the thumb of the preferred hand of 18 human subjects and either hand of two macaque monkeys during a precision grasping task. The to-be-grasped object was a custom-made device composed by two plates which could be variably oriented by a motorized system while keeping constant the size and thus grip dimension. The to-be-grasped plates were covered by an array of capacitive sensors to measure specific features of finger adaptation, namely pressure intensity and centroid location and displacement. Kinematic measurements demonstrated that for human subjects and for monkeys, different plate configurations did not affect wrist velocity and grip aperture during the reaching phase. Consistently, at the instant of fingers-plates contact, pressure centroids were clustered around the same point for all handle configurations. However, small pressure centroid displacements were specifically adopted for each configuration, indicating that both humans and monkeys can display finger adaptation during precision grip. Moreover, humans applied stronger thumb pressure intensity, performed less centroid displacement and required reduced adjustment time, as compared to monkeys. These pressure patterns remain similar when different load forces were required to pull the handle, as ascertained by additional measurements in humans. The present findings indicate that, although humans and monkeys share common features in motor control of grasping, they differ in the adjustment of fingertip pressure, probably because of skill and/or morphology divergences. Such a precision grip device may form the groundwork for future studies on prehension mechanisms. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  6. 78 FR 68907 - Agency Information Collection (Hand and Finger Conditions Disability Benefits Questionnaire...

    Science.gov (United States)

    2013-11-15

    ... Finger Conditions Disability Benefits Questionnaire) Under OMB Review AGENCY: Veterans Benefits... Control No. 2900- NEW (Hand and Finger Conditions Disability Benefits Questionnaire)'' in any... Benefits Questionnaire)''. SUPPLEMENTARY INFORMATION: Title: Hand and Finger Conditions Disability Benefits...

  7. NUMERICALLY DETERMINED TRANSPORT LAWS FOR FINGERING ('THERMOHALINE') CONVECTION IN ASTROPHYSICS

    International Nuclear Information System (INIS)

    Traxler, A.; Garaud, P.; Stellmach, S.

    2011-01-01

    We present the first three-dimensional simulations of fingering convection performed at parameter values approaching those relevant for astrophysics. Our simulations reveal the existence of simple asymptotic scaling laws for turbulent heat and compositional transport, which can be straightforwardly extrapolated from our numerically tractable values to the true astrophysical regime. Our investigation also indicates that thermo-compositional 'staircases', a key consequence of fingering convection in the ocean, cannot form spontaneously in the fingering regime in stellar interiors. Our proposed empirically determined transport laws thus provide simple prescriptions for mixing by fingering convection in a variety of astrophysical situations, and should, from here on, be used preferentially over older and less accurate parameterizations. They also establish that fingering convection does not provide sufficient extra-mixing to explain observed chemical abundances in red giant branch stars.

  8. A new algorithmic approach for fingers detection and identification

    Science.gov (United States)

    Mubashar Khan, Arslan; Umar, Waqas; Choudhary, Taimoor; Hussain, Fawad; Haroon Yousaf, Muhammad

    2013-03-01

    Gesture recognition is concerned with the goal of interpreting human gestures through mathematical algorithms. Gestures can originate from any bodily motion or state but commonly originate from the face or hand. Hand gesture detection in a real time environment, where the time and memory are important issues, is a critical operation. Hand gesture recognition largely depends on the accurate detection of the fingers. This paper presents a new algorithmic approach to detect and identify fingers of human hand. The proposed algorithm does not depend upon the prior knowledge of the scene. It detects the active fingers and Metacarpophalangeal (MCP) of the inactive fingers from an already detected hand. Dynamic thresholding technique and connected component labeling scheme are employed for background elimination and hand detection respectively. Algorithm proposed a new approach for finger identification in real time environment keeping the memory and time constraint as low as possible.

  9. Manipulation of viscous fingering in a radially tapered cell geometry

    Science.gov (United States)

    Bongrand, Grégoire; Tsai, Peichun Amy

    2018-06-01

    When a more mobile fluid displaces another immiscible one in a porous medium, viscous fingering propagates with a partial sweep, which hinders oil recovery and soil remedy. We experimentally investigate the feasibility of tuning such fingering propagation in a nonuniform narrow passage with a radial injection, which is widely used in various applications. We show that a radially converging cell can suppress the common viscous fingering observed in a uniform passage, and a full sweep of the displaced fluid is then achieved. The injection flow rate Q can be further exploited to manipulate the viscous fingering instability. For a fixed gap gradient α , our experimental results show a full sweep at a small Q but partial displacement with fingering at a sufficient Q . Finally, by varying α , we identify and characterize the variation of the critical threshold between stable and unstable displacements. Our experimental results reveal good agreement with theoretical predictions by a linear stability analysis.

  10. Development of a CPM Machine for Injured Fingers.

    Science.gov (United States)

    Fu, Yili; Zhang, Fuxiang; Ma, Xin; Meng, Qinggang

    2005-01-01

    Human fingers are easy to be injured. A CPM machine is a mechanism based on the rehabilitation theory of continuous passive motion (CPM). To develop a CPM machine for the clinic application in the rehabilitation of injured fingers is a significant task. Therefore, based on the theories of evidence based medicine (EBM) and CPM, we've developed a set of biomimetic mechanism after modeling the motions of fingers and analyzing its kinematics and dynamics analysis. We also design an embedded operating system based on ARM (a kind of 32-bit RISC microprocessor). The equipment can achieve the precise control of moving scope of fingers, finger's force and speed. It can serves as a rational checking method and a way of assessment for functional rehabilitation of human hands. Now, the first prototype has been finished and will start the clinical testing in Harbin Medical University shortly.

  11. Innervated boomerang flap for finger pulp reconstruction.

    Science.gov (United States)

    Chen, Shao-Liang; Chiou, Tai-Fung

    2007-11-01

    The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.

  12. Finger-like voids induced by viscous fingering during phase inversion of alumina/PES/NMP suspensions

    KAUST Repository

    Wang, Bo; Lai, Zhiping

    2012-01-01

    membrane structure without such finger-like macrovoids was observed when the suspension was slowly immersed into pure ethanol or a mixture of 70. wt% NMP and 30. wt% water, whereas finger-like macrovoids occurred when the suspension was slid into the non

  13. Characterisation of silica surfaces III: Characterisation of aerosil samples through ethanol adsorption and contact angle studies

    Directory of Open Access Journals (Sweden)

    M.S. Nadiye–Tabbiruka

    2009-12-01

    Full Text Available Aerosil samples, heat treated and then silylated with various silanes at various temperatures have been characterised by adsorption of ethanol at 293 K. Adsorption isotherms were plotted and the BET specific surface areas were determined. Contact angles were measured by the captive bubble method at the three phase contact line in ethanol, on glass slides similarly modified. Silylation was found to alter the ethanol adsorptive properties on aerosil and increase the contact angles on the glass slides to extents that depend on the silane used as well as the concentration of residual silanols and that of surface silyl groups.

  14. A New Rig for Testing Textured Surfaces in Pure Sliding Conditions

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran

    2013-01-01

    machineries are necessary: a press to provide the normal pressure and a tensile machine to perform the axial movements. The test is calibrated so that the correspondence between the normal pressure and the container advancement is found. Preliminary tests are carried out involving a multifunctional and a fine......Throughout the years, it has become more and more important to find new methods for reducing friction and wear occurrence in machine elements. A possible solution is found in texturing the surfaces under tribological contact, as demonstrated by the development and spread of plateau-honed surface...... for cylinder liners. To prove the efficacy of a particular textured surface, it is paramount to perform experimental tests under controlled laboratory conditions. In this paper, a new test rig simulating pure sliding conditions is presented, dubbed axial sliding test. It presents four major components: a rod...

  15. Multipoint contact modeling of nanoparticle manipulation on rough surface

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, M., E-mail: m.zakeri@tabrizu.ac.ir; Faraji, J.; Kharazmi, M. [University of Tabriz, School of Engineering Emerging Technologies (Iran, Islamic Republic of)

    2016-12-15

    In this paper, the atomic force microscopy (AFM)-based 2-D pushing of nano/microparticles investigated on rough substrate by assuming a multipoint contact model. First, a new contact model was extracted and presented based on the geometrical profiles of Rumpf, Rabinovich and George models and the contact mechanics theories of JKR and Schwartz, to model the adhesion forces and the deformations in the multipoint contact of rough surfaces. The geometry of a rough surface was defined by two main parameters of asperity height (size of roughness) and asperity wavelength (compactness of asperities distribution). Then, the dynamic behaviors of nano/microparticles with radiuses in range of 50–500 nm studied during their pushing on rough substrate with a hexagonal or square arrangement of asperities. Dynamic behavior of particles were simulated and compared by assuming multipoint and single-point contact schemes. The simulation results show that the assumption of multipoint contact has a considerable influence on determining the critical manipulation force. Additionally, the assumption of smooth surfaces or single-point contact leads to large error in the obtained results. According to the results of previous research, it anticipated that a particles with the radius less than about 550 nm start to slide on smooth substrate; but by using multipoint contact model, the predicted behavior changed, and particles with radii of smaller than 400 nm begin to slide on rough substrate for different height of asperities, at first.

  16. Influence of contact conditions on vibration induced wear of metals

    International Nuclear Information System (INIS)

    Hofmann, P.J.; Schettler, T.; Wieling, N.; Steininger, D.A.

    1990-01-01

    Unfavourable design characteristics of nuclear power plant steam generators and heat exchangers in general may result in vibration induced tube wear. A systematic investigation was performed on the contact conditions which may appear between heat exchanger tubes and tube support structure and the influence of different parameters e.g., normal contact force, on the resulting steady state wear rates. It is concluded that not only are contact forces and sliding distances important in the wear process but also the type of relative motion has a decisive influence on the resulting wear rates. For a certain 'work rate', the wear rate caused by repeated impact motions between tube and tube support structure may be an order of magnitude higher than that caused by only sliding motion. This is the result of different operating wear mechanisms which are discussed in this paper. (orig.)

  17. Occupational contact urticaria and protein contact dermatitis.

    Science.gov (United States)

    Doutre, Marie-Sylvie

    2005-01-01

    Irritant dermatitis and eczema are the most prevalent occupational skin diseases. Less common are immediate contact reactions such as contact urticaria and protein contact dermatitis. Occupational contact urticaria can be subdivided into two categories, immunological and non immunological. However, some agents can induce these two types of reactions. Contact urticaria to natural rubber latex is particularly frequent among health care personnel, but contact urticaria to a wide variety of other substances occurs in many other occupations. Among those at risk are cooks, bakers, butchers, restaurant personnel, veterinarians, hairdressers, florists, gardeners, and forestry workers. Protein contact dermatitis in some of these occupations is caused principally by proteins of animal or plant origin, especially among individuals with a history of atopic dermatitis. Diagnosis requires careful interrogation, clinical examination and skin tests (open tests and prick tests with immediate lecture) to identify a particular contact allergen.

  18. Adaptive Sliding Mode Control for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    This paper presents a new adaptive sliding mode controller generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The proposed control scheme requires limited knowledge on system parameters, and employs only piston- and valve spool position feedback...... employing parameter adaption through a recursive algorithm is presented. This is based on a reduced order model approximation of a VCD with unmatched valve flow- and cylinder asymmetries. Bounds on parameters are obtained despite lack of parameter knowledge, and the proposed controller demonstrates improved...

  19. Simplified slide production in radiology departments

    International Nuclear Information System (INIS)

    Groves, J.R.; Goethlin, J.H.

    1987-01-01

    A slide-producing system is described, the goal of which is to copy radiographs, typewritten and printed text onto 35 mm film for teaching purposes, records or publication. Automation permits the equipment to be used by persons not familiar with photography. By following simple procedures, high-quality results can be obtained. Advantages of the system are low cost, small space requirements and utilisation of existing facilities such as X-ray dark rooms and processors. Any radiological department requiring quick, low-cost visual materials should consider the convenience of the system described. (orig.)

  20. IWM2011, Slides of the presentations

    International Nuclear Information System (INIS)

    Frankland, J.D.; Rios, A.; Toke, J.; Legouee, E.; Leifels, Y.; Bougault, R.; Russotto, P.; Colonna, M.; Singh, H.; Wigg, P.; Lombardo, I.; Galichet, E.; Gulminelli, F.; De la Mota, V.; La Commara, M.; Ono, A.; Delaume, O.; Najman, R.; Napolitani, P.; Parlog, M.; Lukasik, J.; Raduta, A.; Acosta, L.; Cardella, G.

    2012-01-01

    The aim of the International Workshops on Multifragmentation and related topics (IWM) is to bring together a wide international community from heavy-ion physics in order to debate open questions in the domain of nuclear dynamics and thermodynamics. There will be dedicated sessions on the following topics: -) thermodynamics of finite nuclei and nuclear matter, -) isospin and symmetry energy: from the laboratory to compact stars, -) physics with low-energy radioactive beams, -) dynamics of heavy-ion collisions, -) correlations, dynamics and structure, and -) instrumentation and new detection techniques. This document gathers only the slides of the presentations

  1. Large-scale gravity sliding in the Miocene Shadow Valley Supradetachment Basin, Eastern Mojave Desert, California

    Science.gov (United States)

    Davis, G. A.; Friedmann, S. J.

    2005-12-01

    The Miocene Shadow Valley basin in the eastern Mojave Desert of California developed above the active west-dipping Kingston Range-Halloran Hills extensional detachment fault system between 13.5 and ca. 7 mybp. Although mass-wasting processes are common phenomena in supradetachment basins, the Shadow Valley basin is an exceptional locale for the study of such processes, especially rock-avalanches and gravity sliding. A score of megabreccias, interpreted as rock-avalanche deposits, and half that number of very large (> 1 km 2, up to 200 m thick), internally intact gravity-driven slide sheets are interbedded with various sedimentary facies. The slide sheets, variably composed of Proterozoic crystalline rocks and Proterozoic, Paleozoic, and Tertiary sedimentary strata, moved across both depositional and erosional surfaces in the basin. Although the majority consist of Paleozoic carbonate rocks, the largest slide sheet, the Eastern Star crystalline allochthon, contains Proterozoic gneisses and their sedimentary cover and is now preserved as klippen atop Miocene lacustrine and alluvial fan deposits over an area > 40 km 2. Estimates of slide sheet runouts into the basin from higher eastern and northern source terranes range from approximately a few km to > 10 km; in most cases the exact provenances of the slide blocks are not known. The basal contacts of Shadow Valley slide sheets are characteristically knife sharp, show few signs of lithologic mixing of upper- and lower-plate rocks, and locally exhibit slickensided and striated, planar fault-like bases. Pronounced folding of overridden Miocene lacustrine and fan deposits beneath the Eastern Star allochthon extends to depths up to 40 m at widely scattered localities. We conclude that this slow moving slide sheet encountered isolated topographic asperities (hills) and that stress transfer across the basal slide surface produced folding of footwall strata. Synkinematic gypsum veins in footwall playa sediments, with fibers

  2. Nonintrusive Finger-Vein Recognition System Using NIR Image Sensor and Accuracy Analyses According to Various Factors

    Directory of Open Access Journals (Sweden)

    Tuyen Danh Pham

    2015-07-01

    Full Text Available Biometrics is a technology that enables an individual person to be identified based on human physiological and behavioral characteristics. Among biometrics technologies, face recognition has been widely used because of its advantages in terms of convenience and non-contact operation. However, its performance is affected by factors such as variation in the illumination, facial expression, and head pose. Therefore, fingerprint and iris recognitions are preferred alternatives. However, the performance of the former can be adversely affected by the skin condition, including scarring and dryness. In addition, the latter has the disadvantages of high cost, large system size, and inconvenience to the user, who has to align their eyes with the iris camera. In an attempt to overcome these problems, finger-vein recognition has been vigorously researched, but an analysis of its accuracies according to various factors has not received much attention. Therefore, we propose a nonintrusive finger-vein recognition system using a near infrared (NIR image sensor and analyze its accuracies considering various factors. The experimental results obtained with three databases showed that our system can be operated in real applications with high accuracy; and the dissimilarity of the finger-veins of different people is larger than that of the finger types and hands.

  3. Nonintrusive Finger-Vein Recognition System Using NIR Image Sensor and Accuracy Analyses According to Various Factors.

    Science.gov (United States)

    Pham, Tuyen Danh; Park, Young Ho; Nguyen, Dat Tien; Kwon, Seung Yong; Park, Kang Ryoung

    2015-07-13

    Biometrics is a technology that enables an individual person to be identified based on human physiological and behavioral characteristics. Among biometrics technologies, face recognition has been widely used because of its advantages in terms of convenience and non-contact operation. However, its performance is affected by factors such as variation in the illumination, facial expression, and head pose. Therefore, fingerprint and iris recognitions are preferred alternatives. However, the performance of the former can be adversely affected by the skin condition, including scarring and dryness. In addition, the latter has the disadvantages of high cost, large system size, and inconvenience to the user, who has to align their eyes with the iris camera. In an attempt to overcome these problems, finger-vein recognition has been vigorously researched, but an analysis of its accuracies according to various factors has not received much attention. Therefore, we propose a nonintrusive finger-vein recognition system using a near infrared (NIR) image sensor and analyze its accuracies considering various factors. The experimental results obtained with three databases showed that our system can be operated in real applications with high accuracy; and the dissimilarity of the finger-veins of different people is larger than that of the finger types and hands.

  4. Analysis of mechanisms induced by sliding and corrosion: dedicated apparatus for PWR environments

    International Nuclear Information System (INIS)

    Vernot, JPh

    2004-01-01

    In pressurized water reactors (PWR), some components are submitted to relative motions due to necessary operational processes (localisation and positioning adjustment) or by not wished effects (flow induced vibration). Thus, components and associated supports are typically excited by a large range of kinematics so than complex combinations of wear can occur. Those excitations can lead to sliding, fretting, impact, etc. Furthermore, typical environment in PWR coupling of temperature (320 deg. C), pressure (154 bars) and chemistry solution (deaerated, low conductivity water) involve specific corrosion processes. Apparently, research performed to date did not deal with all the specific parameters involved at PWR conditions. For this purpose, a specific apparatus has been developed in Framatome Technical Center for a better understanding of this complex degradation mechanism where mechanical and corrosion effects are occurring at the same time. Thanks to electromagnets excitation, mechanical investigations can be proposed with the following combined contact type: pure impact, pure sliding and impact plus sliding for several kinds of sample as rod in a ring, rod against a guide. Motion can be induced on a local area or for the total length (orbital excitation). The relative displacement and the contact force are acquired continuously and permit to establish normal and tangential forces, angular position, sliding distance. On the other hand, electrochemistry measurements have been adapted to the specific apparatus and work in the high temperature water environment. The standard mounting with three electrodes has been qualified so that it is possible to adjust or measure current and potential. All the system is computer controlled and with the present apparatus relationship between mechanical parameters and re-passivation can be studied for specific environments, materials and solicitations. In a first step, potential dynamic polarization curves have been established for

  5. Adaptive contact elements for three-dimensional fluid-structure interfaces

    International Nuclear Information System (INIS)

    Kulak, R.F.

    1985-01-01

    A finite element method is developed for treating the mechanics of contact between two deformable bodies which occurs, for example, at fluid-structure interfaces. The method uses a family of adaptive contact elements, which are based upon the penalty method, to handle all of the possible contact configurations that can occur between the discretized contacting bodies. The contact element's nodal connectivity is allowed to change during the computations in order to accommodate finite sliding. The infusion of these elements in the interface results in satisfying the force equilibrium condition during contact. The methodology has been implemented into the NEPTUNE code. Results are presented for an illustrative problem

  6. Adaptive contact elements for three-dimensional fluid-structure interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kulak, R.F.

    1985-01-01

    A finite element method is developed for treating the mechanics of contact between two deformable bodies which occurs, for example, at fluid-structure interfaces. The method uses a family of adaptive contact elements, which are based upon the penalty method, to handle all of the possible contact configurations that can occur between the discretized contacting bodies. The contact element's nodal connectivity is allowed to change during the computations in order to accommodate finite sliding. The infusion of these elements in the interface results in satisfying the force equilibrium condition during contact. The methodology has been implemented into the NEPTUNE code. Results are presented for an illustrative problem.

  7. Torque control of underactuated tendon-driven fingers

    Directory of Open Access Journals (Sweden)

    M. E. Abdallah

    2011-02-01

    Full Text Available Given an underactuated tendon-driven finger, the finger posture is underdetermined and can move freely ("flop" in a region of slack tendons. This work shows that such an underactuated finger can be operated in tendon force control (rather than position control with effective performance. The force control eliminates the indeterminate slack while commanding a parameterized space of desired torques. The torque will either push the finger to the joint limits or wrap around an external object with variable torque – behavior that is sufficient for primarily gripping fingers. In addition, introducing asymmetric joint radii to the design allows the finger to command an expanded range of joint torques and to scan an expanded set of external surfaces. This study is motivated by the design and control of the secondary fingers of the NASA-GM R2 humanoid hand.

    This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

  8. Experimental investigation on the electrical contact behavior of rolling contact connector

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junxing; Yang, Fei, E-mail: yfei2007@mail.xjtu.edu.cn; Luo, Kaiyu; Zhu, Mingliang; Wu, Yi; Rong, Mingzhe [State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049 (China)

    2015-12-15

    Rolling contact connector (RCC) is a new technology utilized in high performance electric power transfer systems with one or more rotating interfaces, such as radars, satellites, wind generators, and medical computed tomography machines. Rolling contact components are used in the RCC instead of traditional sliding contacts to transfer electrical power and/or signal. Since the requirement of the power transmission is increasing in these years, the rolling electrical contact characteristics become more and more important for the long-life design of RCC. In this paper, a typical form of RCC is presented. A series of experimental work are carried out to investigate the rolling electrical contact characteristics during its lifetime. The influence of a variety of factors on the electrical contact degradation behavior of RCC is analyzed under both vacuum and air environment. Based on the surface morphology and elemental composition changes in the contact zone, which are assessed by field emission scanning electron microscope and confocal laser scanning microscope, the mechanism of rolling electrical contact degradation is discussed.

  9. Prediction of Sliding Friction Coefficient Based on a Novel Hybrid Molecular-Mechanical Model.

    Science.gov (United States)

    Zhang, Xiaogang; Zhang, Yali; Wang, Jianmei; Sheng, Chenxing; Li, Zhixiong

    2018-08-01

    Sliding friction is a complex phenomenon which arises from the mechanical and molecular interactions of asperities when examined in a microscale. To reveal and further understand the effects of micro scaled mechanical and molecular components of friction coefficient on overall frictional behavior, a hybrid molecular-mechanical model is developed to investigate the effects of main factors, including different loads and surface roughness values, on the sliding friction coefficient in a boundary lubrication condition. Numerical modelling was conducted using a deterministic contact model and based on the molecular-mechanical theory of friction. In the contact model, with given external loads and surface topographies, the pressure distribution, real contact area, and elastic/plastic deformation of each single asperity contact were calculated. Then asperity friction coefficient was predicted by the sum of mechanical and molecular components of friction coefficient. The mechanical component was mainly determined by the contact width and elastic/plastic deformation, and the molecular component was estimated as a function of the contact area and interfacial shear stress. Numerical results were compared with experimental results and a good agreement was obtained. The model was then used to predict friction coefficients in different operating and surface conditions. Numerical results explain why applied load has a minimum effect on the friction coefficients. They also provide insight into the effect of surface roughness on the mechanical and molecular components of friction coefficients. It is revealed that the mechanical component dominates the friction coefficient when the surface roughness is large (Rq > 0.2 μm), while the friction coefficient is mainly determined by the molecular component when the surface is relatively smooth (Rq < 0.2 μm). Furthermore, optimal roughness values for minimizing the friction coefficient are recommended.

  10. Method of Grasping Control by Computing Internal and External Impedances for Two Robot Fingers, and Its Application to Admittance Control of a Robot Hand-Arm System

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2015-08-01

    Full Text Available Impedance control is an important technology used in the grasping control of a robot hand. Numerous studies related to grasping algorithms have been reported in recent years, with the contact force between robot fingers and the object to be grasped being primarily discussed in most cases. Generally, a coupling effect occurs between the internal loop of the grasping operation and the external loop of the interaction with the environment when a multi-fingered robot hand is used to complete a contact task. Therefore, a robot hand cannot hold an object using a large external force to complete a wide range of tasks by applying the conventional method. In this paper, the coupling of the internal/external forces occurring in grasping operations using multiple fingers is analysed. Then, improved impedance control based on the previous method is proposed as an effective tool to solve the problem of grasping failure caused by single-finger contact. Furthermore, a method for applying the improved grasping algorithm to the admittance control of a robot hand-arm system is also proposed. The proposed method divides the impedance effect into the grasping control of the hand and the cooperative control of the arm, so that expanding the task space and increasing the flexibility of impedance adjustment can be achieved. Experiments were conducted to demonstrate the effectiveness of the proposed method.

  11. A hierarchical classification method for finger knuckle print recognition

    Science.gov (United States)

    Kong, Tao; Yang, Gongping; Yang, Lu

    2014-12-01

    Finger knuckle print has recently been seen as an effective biometric technique. In this paper, we propose a hierarchical classification method for finger knuckle print recognition, which is rooted in traditional score-level fusion methods. In the proposed method, we firstly take Gabor feature as the basic feature for finger knuckle print recognition and then a new decision rule is defined based on the predefined threshold. Finally, the minor feature speeded-up robust feature is conducted for these users, who cannot be recognized by the basic feature. Extensive experiments are performed to evaluate the proposed method, and experimental results show that it can achieve a promising performance.

  12. The relation between the anthropometric characteristics of fingers and cancer

    Directory of Open Access Journals (Sweden)

    Omid Mardanshahi

    2017-07-01

    Full Text Available Anthropometry is a science of human body measurement that could be used for manufacturing artificial limbs or prosthesis, investigating body differences between populations, utilizing in forensics and criminology, or even in the diagnosis of some diseases. Two of the most important anthropometric characteristics are dermatoglyphic patterns and finger length. Many studies have evaluated the relation between these two characteristics in different diseases such as cancers. It assumed that dermatoglyphic patterns and finger length could be used as predictors of some cancers such as gastric, ovarian, prostate, testicular, and breast cancers. In this review, we evaluated the relation between dermatoglyphic variability and finger length in different cancers more precisely.

  13. Using slides to test for changes in crown defoliation assessment methods. Part I: Visual assessment of slides.

    Science.gov (United States)

    Dobbertin, Matthias; Hug, Christian; Mizoue, Nobuya

    2004-11-01

    In this study we used photographs of tree crowns to test whether the assessment methods for tree defoliation in Switzerland have changed over time. We randomly selected 24 series of slides of Norway spruce with field assessments made between 1986 and 1995. The slides were randomly arranged and assessed by three experts without prior knowledge of the year when the slide was taken or the tree number. Defoliation was assessed using the Swiss reference photo guide. Although the correlations between the field assessments and slide assessments were high (Spearman's rank correlation coefficient ranged between 0.79 and 0.83), we found significant differences between field and slide assessments (4.3 to 9% underprediction by the slide assessors) and between the slide assessments. However, no significant trends in field assessment methods could be detected. When the mean differences between field and slide assessments were subtracted, in some years, field assessors consistently underpredicted (1990, 1992) or overpredicted defoliation (1987, 1991). Defoliation tended to be overpredicted in slides taken against the light, and underpredicted for trees with more than 25% crown overlap. We conclude that slide series can be used to detect changes in assessment methods. However, potential observer bias calls for more objective methods of assessment.

  14. Hypersonic sliding target tracking in near space

    Directory of Open Access Journals (Sweden)

    Xiang-yu Zhang

    2015-12-01

    Full Text Available To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA, constant turning (CT and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

  16. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ...

  17. Adaptive Sliding Mode Observer for a Class of Systems

    OpenAIRE

    D.Elleuch; T.Damak

    2010-01-01

    In this paper, the performance of two adaptive observers applied to interconnected systems is studied. The nonlinearity of systems can be written in a fractional form. The first adaptive observer is an adaptive sliding mode observer for a Lipchitz nonlinear system and the second one is an adaptive sliding mode observer having a filtered error as a sliding surface. After comparing their performances throughout the inverted pendulum mounted on a car system, it was shown tha...

  18. Sensorless Sliding Mode Vector Control of Induction Motor Drives

    OpenAIRE

    Gouichiche Abdelmadjid; Boucherit Mohamed Seghir; Safa Ahmed; Messlem Youcef

    2012-01-01

    In this paper we present the design of sliding mode controllers for sensorless field oriented control of induction motor. In order to improve the performance of controllers, the motor speed is controlled by sliding mode regulator with integral sliding surface. The estimated rotor speed used in speed feedback loop is calculated by an adaptive observer based on MRAS (model reference adaptive system) technique .the validity of the proposed scheme is demonstrated by experimental results.

  19. Dermal pocketing following distal finger replantation.

    Science.gov (United States)

    Puhaindran, Mark E; Paavilainen, Pasi; Tan, David M K; Peng, Yeong Pin; Lim, Aymeric Y T

    2010-08-01

    Replantation is an ideal technique for reconstruction following fingertip amputation as it provides 'like for like' total reconstruction of the nail complex, bone pulp tissue and skin with no donor-site morbidity. However, fingertips are often not replanted because veins cannot be found or are thought to be too small to repair. Attempts at 'cap-plasty' or pocketing of replanted tips with and without microvascular anastomosis have been done in the past with varying degrees of success. We prospectively followed up a group of patients who underwent digital replantation and dermal pocketing in the palm to evaluate the outcome of this procedure. There were 10 patients with 14 amputated digits (two thumbs, five index, four middle, two ring and one little) who underwent dermal pocketing of the amputated digit following replantation. Among the 14 digits that were treated with dermal pocketing, 11 survived completely, one had partial atrophy and two were completely lost. Complications encountered included finger stiffness (two patients) and infection of the replanted fingertip with osteomyelitis of the distal phalanx (one patient). We believe that this technique can help increase the chance of survival for distal replantation with an acceptable salvage rate of 85% in our series. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. Was the Scanner Calibration Slide used for its intended purpose?

    Directory of Open Access Journals (Sweden)

    Zong Yaping

    2011-04-01

    Full Text Available Abstract In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response 1. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

  1. Slide less pathology”: Fairy tale or reality?

    Science.gov (United States)

    Indu, M; Rathy, R; Binu, MP

    2016-01-01

    Pathology practice is significantly advanced in various frontiers. Therefore, “slide less digital” pathology will not be a mere imagination in near future. Digitalization of histopathological slides (whole slide imaging [WSI]) is possible with the help of whole slide scanner. The WSI has a positive impact not only in routine practice but also in research field, medical education and bioindustry. Even if digital pathology has definitive advantages, its widespread use is not yet possible. As it is an upcoming technology in our field, this article is aimed to discussessential aspects of WSI. PMID:27601824

  2. Second order sliding mode control for a quadrotor UAV.

    Science.gov (United States)

    Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang

    2014-07-01

    A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Expected sliding distance of vertical slit caisson breakwater

    Science.gov (United States)

    Kim, Dong Hyawn

    2017-06-01

    Evaluating the expected sliding distance of a vertical slit caisson breakwater is proposed. Time history for the wave load to a vertical slit caisson is made. It consists of two impulsive wave pressures followed by a smooth sinusoidal pressure. In the numerical analysis, the sliding distance for an attack of single wave was shown and the expected sliding distance during 50 years was also presented. Those results were compared with a vertical front caisson breakwater without slit. It was concluded that the sliding distance of a vertical slit caisson may be over-estimated if the wave pressure on the caisson is evaluated without considering vertical slit.

  4. The experiment research of the friction sliding isolation structure

    Science.gov (United States)

    Zhang, Shirong; Li, Jiangle; Wang, Sheliang

    2018-04-01

    This paper investigated the theory of the friction sliding isolation structure, The M0S2 solid lubricant was adopted as isolation bearing friction materials, and a new sliding isolation bearing was designed and made. The formula of the friction factor and the compression stress was proposed. The feasibility of the material MoS2 used as the coating material in a friction sliding isolation system was tested on the 5 layers concrete frame model. Two application experiment conditions were presented. The results of the experiment research indicated that the friction sliding isolation technology have a good damping effect.

  5. Low Power Measurements on a Finger Drift Tube Linac

    CERN Document Server

    Schempp, A

    2004-01-01

    The efficiency of RFQs decreases at higher particle energies. The DTL structures used in this energy regions have a defocusing influence on the beam. To achieve a focusing effect, fingers with quadrupole symmetry were added to the drift tubes. Driven by the same power supply as the drift tubes, the fingers do not need an additional power source or feedthrough. Beam dynamics have been studied with PARMTEQ . Detailed analysis of the field distribution was done and the geometry of the finger array has been optimized with respect to beam dynamics. A spiral loaded cavity with finger drift tubes was built up and low power measurements were done. In this contribution, the results of the rf simulating with Microwave Studio are shown in comparison with bead pertubation measurement on a prototype cavity.

  6. Finger Vein Recognition Based on Local Directional Code

    Science.gov (United States)

    Meng, Xianjing; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2012-01-01

    Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP), Local Derivative Pattern (LDP) and Local Line Binary Pattern (LLBP). However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD), this paper represents a new direction based local descriptor called Local Directional Code (LDC) and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP. PMID:23202194

  7. Variability and trait relationships among finger millet accessions in ...

    African Journals Online (AJOL)

    ACSS

    A total of 100 accessions were evaluated for morpho-agronomic characters in a ... head blast incidence, productive tillers plant-1 and grain yield. ... Introduction ... protein, iron and calcium, finger millet ... collection and maintenance has been.

  8. Finger Vein Recognition Based on Local Directional Code

    Directory of Open Access Journals (Sweden)

    Rongyang Xiao

    2012-11-01

    Full Text Available Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP, Local Derivative Pattern (LDP and Local Line Binary Pattern (LLBP. However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD, this paper represents a new direction based local descriptor called Local Directional Code (LDC and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP.

  9. Experience of Percutaneous Trigger Finger Release under Local ...

    African Journals Online (AJOL)

    New Delhi, India. ... This procedure is easy, quicker, less complications and economical with good results. ... Sahu and Gupta: Trigger finger release under local anesthesia .... the most cost-effective treatment is two trials of corticosteroid.

  10. Magnetowetting and sliding motion of a sessile ferrofluid droplet in the presence of a permanent magnet.

    Science.gov (United States)

    Nguyen, Nam-Trung; Zhu, Guiping; Chua, Yong-Chin; Phan, Vinh-Nguyen; Tan, Say-Hwa

    2010-08-03

    Motion of a droplet on a planar surface has applications in droplet-based lab on a chip technology. This paper reports the experimental results of the shape, contact angles, and motion of ferrofluid droplets driven by a permanent magnet on a planar homogeneous surface. The water-based ferrofluid in use is a colloidal suspension of single-domain magnetic nanoparticles. The effect of the magnetic field on the apparent contact angle of the ferrofluid droplet was first investigated. The results show that an increasing magnetic flux decreases the apparent contact angle of a sessile ferrofluid droplet. Next, the dynamic contact angle was investigated by observing the shape and the motion of a sessile ferrofluid droplet. The advancing and receding contact angles of the moving ferrofluid were measured at different moving speeds and magnetic field strengths. The measured contact angles were used to estimate the magnitude of the forces involved in the sliding motion. Scaling analysis was carried out to derive the critical velocity, beyond which the droplet is not able to catch up with the moving magnet.

  11. Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model

    Science.gov (United States)

    Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L.

    2015-12-01

    Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic

  12. Robotic Hand with Flexible Fingers for Grasping Cylindrical Objects

    OpenAIRE

    柴田, 瑞穂

    2015-01-01

    In this manuscript, a robotic hand for grasping a cylindrical object is proposed. This robotic hand has flexible fingers that can hold a cylindrical object during moving. We introduce a grasping strategy for a cylindrical object in terms of state transition graph. In this strategy the robotic hand picks up the cylindrical object utilizing a suction device before the hand grasp the object. We also design the flexible fingers; then, we investigate the validity of this robotic hand via several e...

  13. Finger blood content, light transmission, and pulse oximetry errors.

    Science.gov (United States)

    Craft, T M; Lawson, R A; Young, J D

    1992-01-01

    The changes in light emitting diode current necessary to maintain a constant level of light incident upon a photodetector were measured in 20 volunteers at the two wavelengths employed by pulse oximeters. Three states of finger blood content were assessed; exsanguinated, hyperaemic, and normal. The changes in light emitting diode current with changes in finger blood content were small and are not thought to represent a significant source of error in saturation as measured by pulse oximetry.

  14. Compression and flexural properties of finger jointed mango wood sections

    OpenAIRE

    Kumar, V.S Kishan; Sharma, C.M; Gupta, Sachin

    2014-01-01

    In this paper, an attempt was made to assess the effectiveness of finger jointing in utilising mango wood sections for various end uses like furniture. The study was based on the estimation of Modulus of elasticity and Modulus of rupture under static bending and Maximum Crushing Stress and Modulus of elasticity under compression parallel to grain of finger jointed sections and comparing them with the values measured for clear wood sections from the same lot. For joining the sections, the Poly...

  15. Modeling of constraints and micro-slidings generated between the frictional parts of a valve

    International Nuclear Information System (INIS)

    Cachon, L.; Sudreau, F.; Denape, J.; Lelait, L.

    1995-01-01

    The aim of this modeling is to optimize the use of deposited coatings on the frictional parts of valves (lid/seat). This study is part of a tribological study and uses the CASTEM 2000 finite-elements code developed by the CEA/DMT. The numerical calculations allow to verify that the structural constraints at the contact are lower than the admissible limits of the coatings. The structural constraints field under a static load is calculated and leads to the determination of an adhesion coefficient. This coefficient allows to understand how the sliding initiates. (J.S.). 9 figs

  16. A direct Eulerian method for the simulation of multi-material compressible flows with material sliding

    International Nuclear Information System (INIS)

    Motte, R.; Braeunig, J.P.; Peybernes, M.

    2012-01-01

    As the simulation of compressible flows with several materials is essential for applications studied within the CEA-DAM, the authors propose an approach based on finite volumes with centred variables for the resolution of compressible Euler equations. Moreover, they allow materials to slide with respect to each other as it is the case for water and air, for example. A conservation law is written for each material in a hybrid grid, and a condition of contact between materials under the form of fluxes is expressed. It is illustrated by the case of an intense shock propagating in water and interacting with an air bubble which will be strongly deformed and compressed

  17. Control of Surface Attack by Gallium Alloys in Electrical Contacts.

    Science.gov (United States)

    1986-03-28

    and atmospheric control but does not allow visual observation of the contact brushes. This machine is a small homopolar motor built from mild steel...collectors,gallium, homopolar devices,liquid metals,~- is. ABSTRACT ICNI.. .. w 41N"w -~dv.mp.d Wrllt by Itabata" * Electrical contact between a copp’er...32 5 Test rig with felt metal brushes 32 6 Homopolar test apparatus 33 7 Rewetting of alloy track 33 8 Alloy track after running with finger 34 brushes

  18. Effects of transcranial direct current stimulation on the control of finger force during dexterous manipulation in healthy older adults.

    Directory of Open Access Journals (Sweden)

    Pranav J Parikh

    Full Text Available The contribution of poor finger force control to age-related decline in manual dexterity is above and beyond ubiquitous behavioral slowing. Altered control of the finger forces can impart unwanted torque on the object affecting its orientation, thus impairing manual performance. Anodal transcranial direct current stimulation (tDCS over primary motor cortex (M1 has been shown to improve the performance speed on manual tasks in older adults. However, the effects of anodal tDCS over M1 on the finger force control during object manipulation in older adults remain to be fully explored. Here we determined the effects of anodal tDCS over M1 on the control of grip force in older adults while they manipulated an object with an uncertain mechanical property. Eight healthy older adults were instructed to grip and lift an object whose contact surfaces were unexpectedly made more or less slippery across trials using acetate and sandpaper surfaces, respectively. Subjects performed this task before and after receiving anodal or sham tDCS over M1 on two separate sessions using a cross-over design. We found that older adults used significantly lower grip force following anodal tDCS compared to sham tDCS. Friction measured at the finger-object interface remained invariant after anodal and sham tDCS. These findings suggest that anodal tDCS over M1 improved the control of grip force during object manipulation in healthy older adults. Although the cortical networks for representing objects and manipulative actions are complex, the reduction in grip force following anodal tDCS over M1 might be due to a cortical excitation yielding improved processing of object-specific sensory information and its integration with the motor commands for production of manipulative forces. Our findings indicate that tDCS has a potential to improve the control of finger force during dexterous manipulation in older adults.

  19. Elastic fingering in rotating Hele-Shaw flows

    KAUST Repository

    Carvalho, Gabriel D.

    2014-05-21

    The centrifugally driven viscous fingering problem arises when two immiscible fluids of different densities flow in a rotating Hele-Shaw cell. In this conventional setting an interplay between capillary and centrifugal forces makes the fluid-fluid interface unstable, leading to the formation of fingered structures that compete dynamically and reach different lengths. In this context, it is known that finger competition is very sensitive to changes in the viscosity contrast between the fluids. We study a variant of such a rotating flow problem where the fluids react and produce a gellike phase at their separating boundary. This interface is assumed to be elastic, presenting a curvature-dependent bending rigidity. A perturbative weakly nonlinear approach is used to investigate how the elastic nature of the interface affects finger competition events. Our results unveil a very different dynamic scenario, in which finger length variability is not regulated by the viscosity contrast, but rather determined by two controlling quantities: a characteristic radius and a rigidity fraction parameter. By properly tuning these quantities one can describe a whole range of finger competition behaviors even if the viscosity contrast is kept unchanged. © 2014 American Physical Society.

  20. Elastic fingering in rotating Hele-Shaw flows

    KAUST Repository

    Carvalho, Gabriel D.; Gadê lha, Hermes; Miranda, José A.

    2014-01-01

    The centrifugally driven viscous fingering problem arises when two immiscible fluids of different densities flow in a rotating Hele-Shaw cell. In this conventional setting an interplay between capillary and centrifugal forces makes the fluid-fluid interface unstable, leading to the formation of fingered structures that compete dynamically and reach different lengths. In this context, it is known that finger competition is very sensitive to changes in the viscosity contrast between the fluids. We study a variant of such a rotating flow problem where the fluids react and produce a gellike phase at their separating boundary. This interface is assumed to be elastic, presenting a curvature-dependent bending rigidity. A perturbative weakly nonlinear approach is used to investigate how the elastic nature of the interface affects finger competition events. Our results unveil a very different dynamic scenario, in which finger length variability is not regulated by the viscosity contrast, but rather determined by two controlling quantities: a characteristic radius and a rigidity fraction parameter. By properly tuning these quantities one can describe a whole range of finger competition behaviors even if the viscosity contrast is kept unchanged. © 2014 American Physical Society.

  1. Instability of the sliding Luttinger liquid

    Science.gov (United States)

    Fleurov, V.; Kagalovsky, V.; Lerner, I. V.; Yurkevich, I. V.

    2018-05-01

    We revise a phase diagram for the sliding Luttinger liquid (SLL) of coupled one-dimensional quantum wires packed in two- or three-dimensional arrays in the absence of a magnetic field. We analyse whether physically justifiable (reasonable) inter-wire interactions, i.e. either the screened Coulomb or ‘Coulomb-blockade’ type interactions, stabilise the SLL phase. Calculating the scaling dimensions of the most relevant perturbations (the inter-wire single-particle hybridisation, charge-density wave, and superconducting inter-wire couplings), we find that their combination always destroys the SLL phase for the repulsive intra-wire interaction. However, suppressing the inter-wire tunnelling of repulsive fermions (when the charge-density wave is the only remaining perturbation), one can observe a stability region emerging due to the inter-wire forward scattering interaction.

  2. Robust Sliding Mode Control for Tokamaks

    Directory of Open Access Journals (Sweden)

    I. Garrido

    2012-01-01

    Full Text Available Nuclear fusion has arisen as an alternative energy to avoid carbon dioxide emissions, being the tokamak a promising nuclear fusion reactor that uses a magnetic field to confine plasma in the shape of a torus. However, different kinds of magnetohydrodynamic instabilities may affect tokamak plasma equilibrium, causing severe reduction of particle confinement and leading to plasma disruptions. In this sense, numerous efforts and resources have been devoted to seeking solutions for the different plasma control problems so as to avoid energy confinement time decrements in these devices. In particular, since the growth rate of the vertical instability increases with the internal inductance, lowering the internal inductance is a fundamental issue to address for the elongated plasmas employed within the advanced tokamaks currently under development. In this sense, this paper introduces a lumped parameter numerical model of the tokamak in order to design a novel robust sliding mode controller for the internal inductance using the transformer primary coil as actuator.

  3. 23. Blois meeting 2011- Slides and abstracts

    International Nuclear Information System (INIS)

    Grannis, P.; LeCompte, T.J.; Godbole, R.; Silk, J.; Glover, N.; Verzocchi, M.; Punzi, G.; Maltoni, F.; Narain, M.; Golutvin, A.; Swanson, E.; Iijima, T.; Loizides, C.; Salgado, C.; Oz, Y.; Buchmueller, O.; Pomarol, A.; Taffard, A.; Myers, S.; Lisi, E.; Lindner, M.; Pascoli, S.; Lunardini, C.; Terning, J.; Horava, P.; Gomez, C.; Oberlack, U.; Gunion, J.; Patanchon, G.; Kowalski, M.; Binetruy, P.; Rezzolla, L.; Barsuglia, M.; Montaruli, T.; Sigl, G.; Lykken, J.; Tsybychev, D.; Blanc, F.; Yusa, Yosuke; Oakes, L.; Deschamps, O.; Kolomensky, Y.; Etzion, E.; Espagnon, B.; Niebuhr, C.; Grebenyuk, J.; Blessing, S.; Saoulidou, L.; Bifani, S.; Benhabib, L.; Piskunova, O.; Santel, D.; Fulsom, B.; Zhong, Bin; Tian, Haolai; Fantechi, R.; Daskalakis, G.; Marrouche, J.; Ubiali, M.; Petroff, P.; Bernhard, R.; Kuehn, S.; Aharrouche, M.; Jorda Lope, C.; Sorin, V.; Venturi, N.; Zaro, M.; Desai, Satish; Yu, Geum Bong; Elmsheuser, J.; Botta, C.; Couderc, F.; Rauch, M.; Lister, A.; Saleem, M.; Aldaya Martin, M.; Takeuchi, M.; Soustruznik, K.; Rao, Kanishka; Moreau, G.; Janicsko, J.; Garrido, X.; Mueller, T.; Mehdiyev, R.; Zimmerman, E.; Li, T.; Raselli, G.L.; Bellerive, A.; Manecki, S.M.; Studenikin, A.; Lamblin, J.; Censier, B.; Cooley, J.; Moulin, E.; Baldini, L.; Carmona-Benitez, C.; Tytgat, M.; Faldowski, A.; Rao, Soumya; Serra, J.; Neiman, Y.; Novikov, V.; De Aquino, P.; Vazquez-Jauregui, E.; Canonica, L.; Cattaneo, P.; Gruenendahl, S.; Widl, E.E.; Cote, D.; Falkowski, A.; Torre, R.; Vidal, M.; De Guio, F.; Cuhadar, Donszelmann; Colin, P.; Komin, Nukri; Palioselitis, D.; Baret, B.; Toscano, S.; Roth, M.; Deligny, O.; Guy, Julien; Chotard, N.; Rapetti, D.; Lychkovskiy, O.; Staggs, S.; Wehus, I.C.

    2013-01-01

    This conference on 'Particle Physics and Cosmology' will emphasize the increasing interplay between high energy accelerator based physics and cosmology. The meeting will be articulated around the results and their impact on current theories from the 3 major new experimental and observational facilities which are coming on line or have recently been commissioned: the Large Hadron Collider at CERN, the Planck satellite, and the Herschel satellite. The topics will include: -) the Standard Model in particle physics, in new data and analyses, -) the search for the Higgs boson, -) theories of and searches for physics beyond the Standard Model, -) heavy flavour physics, -) neutrino physics (astrophysical and laboratory), -) dark matter, dark energy and recent advances in cosmology. This document gathers the program, the slides and some abstracts of the presentations

  4. Screening and dotting virtual slides: A new challenge for cytotechnologists

    Directory of Open Access Journals (Sweden)

    Walid E Khalbuss

    2013-01-01

    Full Text Available Digital images are increasingly being used in cytopathology. Whole-slide imaging (WSI is a digital imaging modality that uses computerized technology to scan and convert entire cytology glass slides into digital images that can be viewed on a digital display using the image viewer software. Digital image acquisition of cytology glass slides has improved significantly over the years due to the use of liquid-based preparations and advances in WSI scanning technology such as automatic multipoint pre-scan focus technology or z-stack scanning technology. Screening cytotechnologists are responsible for every cell that is present on an imaged slide. One of the challenges users have to overcome is to establish a technique to review systematically the entire imaged slide and to dot selected abnormal or significant findings. The scope of this article is to review the current user interface technology available for virtual slide navigation when screening digital slides in cytology. WSI scanner vendors provide tools, built into the image viewer software that allow for a more systematic navigation of the virtual slides, such as auto-panning, keyboard-controlled slide navigation and track map. Annotation tools can improve communication between the screener and the final reviewer or can be used for education. The tracking functionality allows recording of the WSI navigation process and provides a mechanism for confirmation of slide coverage by the screening cytotechnologist as well as a useful tool for quality assurance. As the WSI technology matures, additional features and tools to support navigation of a cytology virtual slide are anticipated.

  5. Dancing droplets: Contact angle, drag, and confinement

    Science.gov (United States)

    Benusiglio, Adrien; Cira, Nate; Prakash, Manu

    2015-11-01

    When deposited on a clean glass slide, a mixture of water and propylene glycol forms a droplet of given contact angle, when both pure liquids spread. (Cira, Benusiglio, Prakash: Nature, 2015). The droplet is stabilized by a gradient of surface tension due to evaporation that induces a Marangoni flow from the border to the apex of the droplets. The apparent contact angle of the droplets depends on both their composition and the external humidity as captured by simple models. These droplets present remarkable properties such as lack of a large pinning force. We discuss the drag on these droplets as a function of various parameters. We show theoretical and experimental results of how various confinement geometries change the vapor gradient and the dynamics of droplet attraction.

  6. Surgery for Dupuytren's contracture of the fingers.

    Science.gov (United States)

    Rodrigues, Jeremy N; Becker, Giles W; Ball, Cathy; Zhang, Weiya; Giele, Henk; Hobby, Jonathan; Pratt, Anna L; Davis, Tim

    2015-12-09

    Dupuytren's disease is a benign fibroproliferative disorder that causes the fingers to be drawn into the palm via formation of new tissue under the glabrous skin of the hand. This disorder causes functional limitations, but it can be treated through a variety of surgical techniques. As a chronic condition, it tends to recur. To assess the benefits and harms of different surgical procedures for treatment of Dupuytren's contracture of the index, middle, ring and little fingers. We initially searched the following databases on 17 September 2012, then re-searched them on 10 March 2014 and on 20 May 2015: the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library, the British Nursing Index and Archive (BNI), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE, the Latin American Caribbean Health Sciences Literature (LILACS), Ovid MEDLINE, Ovid MEDLINE-In-Process and Other Non-Indexed Citations, ProQuest (ABI/INFORM Global and Dissertations & Theses), the Institute for Scientific Information (ISI) Web of Science and clinicaltrials.gov. We reviewed the reference lists of short-listed articles to identify additional suitable studies. We included randomised clinical trials and controlled clinical trials in which groups received surgical intervention for Dupuytren's disease of the index, middle, ring or little finger versus control, or versus another intervention (surgical or otherwise). We excluded the thumb, as cords form on the radial aspect of the thumb and thus are not readily accessible in terms of angular deformity. Furthermore, thumb disease is rare. A minimum of two review authors independently reviewed search results to select studies for inclusion by using pre-specified criteria, assessed risk of bias of included studies and extracted data from included studies.We grouped outcomes into the following categories: (1) hand function, (2) other patient-reported outcomes (e.g. satisfaction, pain), (3) early objective

  7. Triaxial slide-hold-slide shear experiment of sedimentary rock under drain condition

    International Nuclear Information System (INIS)

    Kishida, Kiyoshi; Yano, Takao; Elsworth, Derek; Yasuhara, Hideaki; Nakashima, Shinichiro

    2011-01-01

    When discussing the mechanical and hydro-mechanical properties of rock masses under the long-term holding, the variation of rock structure and the change of shear band condition should be discussed in considering the effect of thermal and chemical influences. In this research, the triaxial shear experiment under drain condition was conducted through sedimentary rock, and in the residual stress state, the slide-hold-slide processes were applied to these triaxial experiments. The experiments were carried out in 3 kinds of confining conditions and 2 kinds of thermal conditions. Consequently, the healing phenomena can be observed and the shear strength recovery is also confirmed in process of the holding time. (author)

  8. Contact Dermatitis in Pediatrics.

    Science.gov (United States)

    Pelletier, Janice L; Perez, Caroline; Jacob, Sharon E

    2016-08-01

    Contact dermatitis is an umbrella term that describes the skin's reaction to contacted noxious or allergenic substances. The two main categories of contact dermatitis are irritant type and allergic type. This review discusses the signs, symptoms, causes, and complications of contact dermatitis. It addresses the testing, treatment, and prevention of contact dermatitis. Proper management of contact dermatitis includes avoidance measures for susceptible children. Implementation of a nickel directive (regulating the use of nickel in jewelry and other products that come into contact with the skin) could further reduce exposure to the most common allergens in the pediatric population. [Pediatr Ann. 2016;45(8):e287-e292.]. Copyright 2016, SLACK Incorporated.

  9. Dynamics of Linker Residues Modulate the Nucleic Acid Binding Properties of the HIV-1 Nucleocapsid Protein Zinc Fingers

    Science.gov (United States)

    Zargarian, Loussiné; Tisné, Carine; Barraud, Pierre; Xu, Xiaoqian; Morellet, Nelly; René, Brigitte; Mély, Yves; Fossé, Philippe; Mauffret, Olivier

    2014-01-01

    The HIV-1 nucleocapsid protein (NC) is a small basic protein containing two zinc fingers (ZF) separated by a short linker. It is involved in several steps of the replication cycle and acts as a nucleic acid chaperone protein in facilitating nucleic acid strand transfers occurring during reverse transcription. Recent analysis of three-dimensional structures of NC-nucleic acids complexes established a new property: the unpaired guanines targeted by NC are more often inserted in the C-terminal zinc finger (ZF2) than in the N-terminal zinc finger (ZF1). Although previous NMR dynamic studies were performed with NC, the dynamic behavior of the linker residues connecting the two ZF domains remains unclear. This prompted us to investigate the dynamic behavior of the linker residues. Here, we collected 15N NMR relaxation data and used for the first time data at several fields to probe the protein dynamics. The analysis at two fields allows us to detect a slow motion occurring between the two domains around a hinge located in the linker at the G35 position. However, the amplitude of motion appears limited in our conditions. In addition, we showed that the neighboring linker residues R29, A30, P31, R32, K33 displayed restricted motion and numerous contacts with residues of ZF1. Our results are fully consistent with a model in which the ZF1-linker contacts prevent the ZF1 domain to interact with unpaired guanines, whereas the ZF2 domain is more accessible and competent to interact with unpaired guanines. In contrast, ZF1 with its large hydrophobic plateau is able to destabilize the double-stranded regions adjacent to the guanines bound by ZF2. The linker residues and the internal dynamics of NC regulate therefore the different functions of the two zinc fingers that are required for an optimal chaperone activity. PMID:25029439

  10. Evaluation of finger millet incorporated noodles for nutritive value and glycemic index

    OpenAIRE

    Shukla, Kamini; Srivastava, Sarita

    2011-01-01

    The present study was undertaken to develop finger millet incorporated noodles for diabetic patients. Finger millet variety VL-149 was taken. The finger millet flour and refined wheat flour (RWF) were evaluated for nutrient composition. The finger millet flour (FMF) was blended in various proportions (30 to 50%) in refined wheat flour and used for the preparation of noodles. Control consisted of RWF noodles. Sensory quality and nutrient composition of finger millet noodles was evaluated. The ...

  11. Time Dependent Frictional Changes in Ice due to Contact Area Changes

    Science.gov (United States)

    Sevostianov, V.; Lipovsky, B. P.; Rubinstein, S.; Dillavou, S.

    2017-12-01

    Sliding processes along the ice-bed interface of Earth's great ice sheets are the largest contributor to our uncertainty in future sea level rise. Laboratory experiments that have probed sliding processes have ubiquitously shown that ice-rock interfaces strengthen while in stationary contact (Schulson and Fortt, 2013; Zoet et al., 2013; McCarthy et al., 2017). This so-called frictional ageing effect may have profound consequences for ice sheet dynamics because it introduces the possibility of basal strength hysteresis. Furthermore this effect is quite strong in ice-rock interfaces (more than an order of magnitude more pronounced than in rock-rock sliding) and can double in frictional strength in a matter of minutes, much faster than most frictional aging (Dieterich, 1972; Baumberger and Caroli, 2006). Despite this importance, the underling physics of frictional ageing of ice remain poorly understood. Here we conduct laboratory experiments to image the microscopic points of contact along an ice-glass interface. We optically measure changes in the real area of contact over time using measurements of this reflected optical light intensity. We show that contact area increases with time of stationary contact. This result suggests that thermally enhanced creep of microscopic icy contacts is responsible for the much larger frictional ageing observed in ice-rock versus rock-rock interfaces. Furthermore, this supports a more physically detailed description of the thermal dependence of basal sliding than that used in the current generation of large scale ice sheet models.

  12. Thermal stability improvement of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations using non-uniform finger spacing

    International Nuclear Information System (INIS)

    Chen Liang; Zhang Wan-Rong; Jin Dong-Yue; Shen Pei; Xie Hong-Yun; Ding Chun-Bao; Xiao Ying; Sun Bo-Tao; Wang Ren-Qing

    2011-01-01

    A method of non-uniform finger spacing is proposed to enhance thermal stability of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations. Temperature distribution on the emitter fingers of a multi-finger SiGe heterojunction bipolar transistor is studied using a numerical electro-thermal model. The results show that the SiGe heterojunction bipolar transistor with non-uniform finger spacing has a small temperature difference between fingers compared with a traditional uniform finger spacing heterojunction bipolar transistor at the same power dissipation. What is most important is that the ability to improve temperature non-uniformity is not weakened as power dissipation increases. So the method of non-uniform finger spacing is very effective in enhancing the thermal stability and the power handing capability of power device. Experimental results verify our conclusions. (interdisciplinary physics and related areas of science and technology)

  13. Effect of the linkers between the zinc fingers in zinc finger protein 809 on gene silencing and nuclear localization

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Yu, E-mail: ichida-y@ncchd.go.jp; Utsunomiya, Yuko; Onodera, Masafumi

    2016-03-18

    Zinc finger protein 809 (ZFP809) belongs to the Kruppel-associated box-containing zinc finger protein (KRAB-ZFP) family and functions in repressing the expression of Moloney murine leukemia virus (MoMLV). ZFP809 binds to the primer-binding site (PBS)located downstream of the MoMLV-long terminal repeat (LTR) and induces epigenetic modifications at integration sites, such as repressive histone modifications and de novo DNA methylation. KRAB-ZFPs contain consensus TGEKP linkers between C2H2 zinc fingers. The phosphorylation of threonine residues within linkers leads to the inactivation of zinc finger binding to target sequences. ZFP809 also contains consensus linkers between zinc fingers. However, the function of ZFP809 linkers remains unknown. In the present study, we constructed ZFP809 proteins containing mutated linkers and examined their ability to silence transgene expression driven by MLV, binding ability to MLV PBS, and cellular localization. The results of the present study revealed that the linkers affected the ability of ZFP809 to silence transgene expression. Furthermore, this effect could be partly attributed to changes in the localization of ZFP809 proteins containing mutated linkers. Further characterization of ZFP809 linkers is required for understanding the functions and features of KRAB-ZFP-containing linkers. - Highlights: • ZFP809 has three consensus linkers between the zinc fingers. • Linkers are required for ZFP809 to silence transgene expression driven by MLV-LTR. • Linkers affect the precise nuclear localization of ZFP809.

  14. Optimizing Student Learning: Examining the Use of Presentation Slides

    Science.gov (United States)

    Strauss, Judy; Corrigan, Hope; Hofacker, Charles F.

    2011-01-01

    Sensory overload and split attention result in reduced learning when instructors read slides with bullet points and complex graphs during a lecture. Conversely, slides containing relevant visual elements, when accompanied by instructor narration, use both the visual and verbal channels of a student's working memory, thus improving the chances of…

  15. A Transformational Approach to Slip-Slide Factoring

    Science.gov (United States)

    Steckroth, Jeffrey

    2015-01-01

    In this "Delving Deeper" article, the author introduces the slip-slide method for solving Algebra 1 mathematics problems. This article compares the traditional method approach of trial and error to the slip-slide method of factoring. Tools that used to be taken for granted now make it possible to investigate relationships visually,…

  16. Sliding behaviors of elastic cylindrical tanks under seismic loading

    International Nuclear Information System (INIS)

    Kobayashi, N.

    1993-01-01

    There is a paper that reports on the occurrence of sliding in several oil tanks on Alaskan earthquake of 1964. This incident appears to be in need of further investigation for the following reasons: First, in usual seismic designing of cylindrical tanks ('tanks'), sliding is considered to occur when the lateral inertial force exceeds the static friction force. When the tank in question can be taken as a rigid body, this rule is known to hold true. If the tank is capable of undergoing a considerable amount of elastic deformation, however, its applicability has not been proved. Second, although several studies have been done on the critical conditions for static sliding the present author is unaware of like ones made on the dynamic sliding, except for the pioneering work of Sogabe, in which they have empirically indicated possibility of sliding to occur under the force of sloshing. Third, this author has shown earlier on that tanks, if not anchored properly, will start rocking, inducing uplifting of the base plate, even at a relatively small seismic acceleration of 10 gal or so. The present study has been conducted with these observations for the background. Namely, based on a notion that elastic deformation given rise to by rocking oscillation should be incorporated as an important factor in any set of critical conditions for the onset of sliding, a series of shaking table experiments were performed for rigid steel block to represent the rigid tanks ('rigid model') and a model tank having a same sort of plate thickness-to-diameter ratio as industrial tanks to represent the elastic cylindrical tanks ('elastic model'). Following observations have been obtained for the critical condition of the onset of sliding: (1) sliding of rigid tanks will occur when the lateral force given rise to by oscillation exceeds the static, or the Coulombic, friction force. (2) if vertical oscillation is imposed on the lateral oscillation, the lateral force needed to induce sliding of a

  17. Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

    Science.gov (United States)

    Chen, Hongbin

    2018-03-01

    Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

  18. Static and dynamic friction in sliding colloidal monolayers.

    Science.gov (United States)

    Vanossi, Andrea; Manini, Nicola; Tosatti, Erio

    2012-10-09

    In a pioneer experiment, Bohlein et al. realized the controlled sliding of two-dimensional colloidal crystals over laser-generated periodic or quasi-periodic potentials. Here we present realistic simulations and arguments that besides reproducing the main experimentally observed features give a first theoretical demonstration of the potential impact of colloid sliding in nanotribology. The free motion of solitons and antisolitons in the sliding of hard incommensurate crystals is contrasted with the soliton-antisoliton pair nucleation at the large static friction threshold F(s) when the two lattices are commensurate and pinned. The frictional work directly extracted from particles' velocities can be analyzed as a function of classic tribological parameters, including speed, spacing, and amplitude of the periodic potential (representing, respectively, the mismatch of the sliding interface and the corrugation, or "load"). These and other features suggestive of further experiments and insights promote colloid sliding to a unique friction study instrument.

  19. Advances in sliding mode control concept, theory and implementation

    CERN Document Server

    Janardhanan, S; Spurgeon, Sarah

    2013-01-01

    The sliding mode control paradigm has become a mature technique for the design of robust controllers for a wide class of systems including nonlinear, uncertain and time-delayed systems. This book is a collection of plenary and invited talks delivered at the 12th IEEE International Workshop on Variable Structure System held at the Indian Institute of Technology, Mumbai, India in January 2012. After the workshop, these researchers were invited to develop book chapters for this edited collection in order to reflect the latest results and open research questions in the area. The contributed chapters have been organized by the editors to reflect the various themes of sliding mode control which are the current areas of theoretical research and applications focus; namely articulation of the fundamental underpinning theory of the sliding mode design paradigm, sliding modes for decentralized system representations, control of time-delay systems, the higher order sliding mode concept, results applicable to nonlinear an...

  20. Friction of human skin against smooth and rough glass as a function of the contact pressure

    NARCIS (Netherlands)

    Derler, S.; Gerhardt, L.C.; Lenz, A.; Bertaux, E.; Hadad, M.

    2009-01-01

    The friction behaviour of human skin was studied by combining friction measurements using a tri-axial force plate with skin contact area measurements using a pressure sensitive film. Four subjects carried out friction measurement series, in which they rubbed the index finger pad and the edge of the

  1. Electrical charging effects on the sliding friction of a model nano-confined ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Capozza, R.; Vanossi, A. [International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste (Italy); CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); Benassi, A. [CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, 01062 Dresden (Germany); Tosatti, E. [International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste (Italy); CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34014 Trieste (Italy)

    2015-10-14

    Recent measurements suggest the possibility to exploit ionic liquids (ILs) as smart lubricants for nano-contacts, tuning their tribological and rheological properties by charging the sliding interfaces. Following our earlier theoretical study of charging effects on nanoscale confinement and squeezout of a model IL, we present here molecular dynamics simulations of the frictional and lubrication properties of that model under charging conditions. First, we describe the case when two equally charged plates slide while being held together to a confinement distance of a few molecular layers. The shear sliding stress is found to rise strongly and discontinuously as the number of IL layers decreases stepwise. However, the shear stress shows, within each given number of layers, only a weak dependence upon the precise value of the normal load, a result in agreement with data extracted from recent experiments. We subsequently describe the case of opposite charging of the sliding plates and follow the shear stress when the charging is slowly and adiabatically reversed in the course of time, under fixed load. Despite the fixed load, the number and structure of the confined IL layers change with changing charge, and that in turn drives strong friction variations. The latter involves first of all charging-induced freezing of the IL film, followed by a discharging-induced melting, both made possible by the nanoscale confinement. Another mechanism for charging-induced frictional changes is a shift of the plane of maximum shear from mid-film to the plate-film interface, and vice versa. While these occurrences and results invariably depend upon the parameters of the model IL and upon its specific interaction with the plates, the present study helps identifying a variety of possible behavior, obtained under very simple assumptions, while connecting it to an underlying equilibrium thermodynamics picture.

  2. Experiments on vibration-driven stick-slip locomotion: A sliding bifurcation perspective

    Science.gov (United States)

    Du, Zhouwei; Fang, Hongbin; Zhan, Xiong; Xu, Jian

    2018-05-01

    Dry friction appears at the contact interface between two surfaces and is the source of stick-slip vibrations. Instead of being a negative factor, dry friction is essential for vibration-driven locomotion system to take effect. However, the dry-friction-induced stick-slip locomotion has not been fully understood in previous research, especially in terms of experiments. In this paper, we experimentally study the stick-slip dynamics of a vibration-driven locomotion system from a sliding bifurcation perspective. To this end, we first design and build a vibration-driven locomotion prototype based on an internal piezoelectric cantilever. By utilizing the mechanical resonance, the small piezoelectric deformation is significantly amplified to drive the prototype to achieve effective locomotion. Through identifying the stick-slip characteristics in velocity histories, we could categorize the system's locomotion into four types and obtain a stick-slip categorization diagram. In each zone of the diagram the locomotion exhibits qualitatively different stick-slip dynamics. Such categorization diagram is actually a sliding bifurcation diagram; crossing from one stick-slip zone to another corresponds to the triggering of a sliding bifurcation. In addition, a simplified single degree-of-freedom model is established, with the rationality of simplification been explained theoretically and numerically. Based on the equivalent model, a numerical stick-slip categorization is also obtained, which shows good agreement with the experiments both qualitatively and quantitatively. To the best of our knowledge, this is the first work that experimentally generates a sliding bifurcation diagram. The obtained stick-slip categorizations deepen our understanding of stick-slip dynamics in vibration-driven systems and could serve as a base for system design and optimization.

  3. Nailfold Capillaroscopy of Fingers and Toes - Variations of Normal.

    Science.gov (United States)

    Lambova, Sevdalina Nikolova; Muller-Ladner, Ulf

    2018-04-20

    Nailfold capillaroscopy is the only method for morphological assessment of nutritive capillaries. The literature data about capillaroscopic findings in healthy individuals are scarce. To evaluate and compare the capillaroscopic findings of fingers and toes in healthy subjects. 22 healthy individuals were included in the study. Capillaroscopic examination was performed with videocapillaroscope Videocap 3.0 (DS Medica). Exclusion criteria were as follows: history of vasospasm, presence of accompanying diseases, taking any medications, arterial hypertension in first degree relatives, overweight or obesity (body mass index > 25kg/m2) and presence of chronic arterial or venous insufficiency. Poor visibility of nailfold capillaries was found significantly more frequently in the toes (22.7%, 5/22) as compared with fingers (0/22). Slight irregularities in capillary distribution and orientation to their parallel axis were significantly more common in the toes (31.8%, 7/22) as compared with fingers (9%, 2/22), (p10%) was found significantly more often in the toes (12/22) as compared with fingers (6/22, χ2=6.769, p<0.05). Short capillary loops (length<100µm) were observed significantly more often in the toes (11/22 - toes, 1/22 - fingers, χ2=14.666, p<0.05). Capillaroscopic examination of the toes shows some differences as compared to those of the fingers such as greater number of cases with poor visibility and slight irregularities of distribution, greater number of shorter capillaries and increased tortuosity, which might be related to the thicker epidermis of the toes and increased capillary pressure due to gravity. The values of the major capillaroscopic parameters such as capillary diameters and capillary density in fingers and toes do not differ significantly. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Making fingers and words count in a cognitive robot

    Directory of Open Access Journals (Sweden)

    Vivian Milagros De La Cruz

    2014-02-01

    Full Text Available Evidence from developmental as well as neuroscientific studies suggest that finger counting activity plays an important role in the acquisition of numerical skills in children. It has been claimed that this skill helps in building motor-based representations of number that continue to influence number processing well into adulthood, facilitating the emergence of number concepts from sensorimotor experience through a bottom-up process. The act of counting also involves the acquisition and use of a verbal number system of which number words are the basic building blocks. Using a Cognitive Developmental Robotics paradigm we present results of a modeling experiment on whether finger counting and the association of number words (or tags to fingers, could serve to bootstrap the representation of number in a cognitive robot, enabling it to perform basic numerical operations such as addition. The cognitive architecture of the robot is based on artificial neural networks, which enable the robot to learn both sensorimotor skills (finger counting and linguistic skills (using number words. The results obtained in our experiments show that learning the number words in sequence along with finger configurations helps the fast building of the initial representation of number in the robot. Number knowledge, is instead, not as efficiently developed when number words are learned out of sequence without finger counting. Furthermore, the internal representations of the finger configurations themselves, developed by the robot as a result of the experiments, sustain the execution of basic arithmetic operations, something consistent with evidence coming from developmental research with children. The model and experiments demonstrate the importance of sensorimotor skill learning in robots for the acquisition of abstract knowledge such as numbers.

  5. Contact mechanics: contact area and interfacial separation from small contact to full contact

    International Nuclear Information System (INIS)

    Yang, C; Persson, B N J

    2008-01-01

    We present a molecular dynamics study of the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. The numerical calculations mainly focus on the contact area and the interfacial separation from small contact (low load) to full contact (high load). For a small load the contact area varies linearly with the load and the interfacial separation depends logarithmically on the load. For a high load the contact area approaches the nominal contact area (i.e. complete contact), and the interfacial separation approaches zero. The numerical results have been compared with analytical theory and experimental results. They are in good agreement with each other. The present findings may be very important for soft solids, e.g. rubber, or for very smooth surfaces, where complete contact can be reached at moderately high loads without plastic deformation of the solids

  6. Rubber friction on road surfaces: Experiment and theory for low sliding speeds

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, B.; Persson, B. N. J. [PGI, FZ Jülich, 52425 Jülich (Germany); Oh, Y. R.; Nam, S. K.; Jeon, S. H. [Hankook Tire Co. LTD., 112 Gajeongbuk-ro, Yuseong-gu, Daejeon 305-725 (Korea, Republic of)

    2015-05-21

    We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

  7. Magic Ring: A Finger-Worn Device for Multiple Appliances Control Using Static Finger Gestures

    Directory of Open Access Journals (Sweden)

    Tongjun Huang

    2012-05-01

    Full Text Available An ultimate goal for Ubiquitous Computing is to enable people to interact with the surrounding electrical devices using their habitual body gestures as they communicate with each other. The feasibility of such an idea is demonstrated through a wearable gestural device named Magic Ring (MR, which is an original compact wireless sensing mote in a ring shape that can recognize various finger gestures. A scenario of wireless multiple appliances control is selected as a case study to evaluate the usability of such a gestural interface. Experiments comparing the MR and a Remote Controller (RC were performed to evaluate the usability. From the results, only with 10 minutes practice, the proposed paradigm of gestural-based control can achieve a performance of completing about six tasks per minute, which is in the same level of the RC-based method.

  8. Diagnostic aspects of vibration-induced white finger.

    Science.gov (United States)

    Olsen, Niels

    2002-01-01

    Vibration-induced white finger (VWF) is a secondary type of Raynaud's phenomenon (RP) caused by exposure to hand-arm vibration. The present review concerns the cold-provoked attack of RP in vasospastic VWF. It concentrates on the most common clinical and laboratory methods used to diagnose RP in vibration-exposed subjects. Some physiological aspects of the attack of RP are mentioned to elucidate the diagnostic principles of the tests. Anamnestic diagnostics by medical interviews and questionnaires as well as cold-provocation tests with detection of finger colour, finger systolic blood pressure (FSP), recovery time of finger skin temperature and recovery time of normal nail colour after nail compression are mentioned. The discriminative capacity and the reproducibility of the tests are discussed. Cold-provocation tests with detection of finger colour or zero FSP during cooling are recommended to be used if an attack of RP has to be registered for diagnostic or medico-legal purposes in individual cases. An abnormal reduction in FSP during cooling makes a history of RP very probable and is a suitable laboratory test for groups of subjects. Both recovery tests may be useful screening tests in field studies of vibration-exposed subject groups.

  9. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    Energy Technology Data Exchange (ETDEWEB)

    Yasumoto, Kyoden; Fujino, Masayuki; Supriyadi (Kyoto Univ., Uji (Japan). Research Inst. for Food Science); Suzuki, Tetsuya; Hayashi, Toru

    1991-08-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10{sup 8}/g. Turmeric finger which was irradiated by electron beam at 10 kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10 kGy and 20 kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers. (author).

  10. Finger Vein Recognition Based on Personalized Weight Maps

    Science.gov (United States)

    Yang, Gongping; Xiao, Rongyang; Yin, Yilong; Yang, Lu

    2013-01-01

    Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs). The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition. PMID:24025556

  11. The biometric recognition on contactless multi-spectrum finger images

    Science.gov (United States)

    Kang, Wenxiong; Chen, Xiaopeng; Wu, Qiuxia

    2015-01-01

    This paper presents a novel multimodal biometric system based on contactless multi-spectrum finger images, which aims to deal with the limitations of unimodal biometrics. The chief merits of the system are the richness of the permissible texture and the ease of data access. We constructed a multi-spectrum instrument to simultaneously acquire three different types of biometrics from a finger: contactless fingerprint, finger vein, and knuckleprint. On the basis of the samples with these characteristics, a moderate database was built for the evaluation of our system. Considering the real-time requirements and the respective characteristics of the three biometrics, the block local binary patterns algorithm was used to extract features and match for the fingerprints and finger veins, while the Oriented FAST and Rotated BRIEF algorithm was applied for knuckleprints. Finally, score-level fusion was performed on the matching results from the aforementioned three types of biometrics. The experiments showed that our proposed multimodal biometric recognition system achieves an equal error rate of 0.109%, which is 88.9%, 94.6%, and 89.7% lower than the individual fingerprint, knuckleprint, and finger vein recognitions, respectively. Nevertheless, our proposed system also satisfies the real-time requirements of the applications.

  12. A Method for Recognizing State of Finger Flexure and Extension

    Science.gov (United States)

    Terado, Toshihiko; Fujiwara, Osamu

    In our country, the handicapped and the elderly people in bed increase rapidly. In the bedridden person’s daily life, there may be limitations in the physical movement and the means of mutual communication. For the support of their comfortable daily lives, therefore, the development of human interface equipment becomes an important task. The equipment of this kind is being already developed by means of laser beam, eye-tracking, breathing motion and myo-electric signals, while the attachment and handling are normally not so easy. In this study, paying attention to finger motion, we have developed human interface equipment easily attached to the body, which enables one to measure the finger flexure and extension for mutual communication. The state of finger flexure and extension is identified by a threshold level analysis from the 3D-locus data for the finger movement, which can be measured through the infrared rays from the LED markers attached to a glove with the previously developed prototype system. We then have confirmed from an experiment that nearly 100% recognition for the finger movement can be achieved.

  13. The genetic map of finger millet, Eleusine coracana.

    Science.gov (United States)

    Dida, Mathews M; Srinivasachary; Ramakrishnan, Sujatha; Bennetzen, Jeffrey L; Gale, Mike D; Devos, Katrien M

    2007-01-01

    Restriction fragment length polymorphism (RFLP), amplified fragment length polymorphism (AFLP), expressed-sequenced tag (EST), and simple sequence repeat (SSR) markers were used to generate a genetic map of the tetraploid finger millet (Eleusine coracana subsp. coracana) genome (2n = 4x = 36). Because levels of variation in finger millet are low, the map was generated in an inter-subspecific F(2) population from a cross between E. coracana subsp. coracana cv. Okhale-1 and its wild progenitor E. coracana subsp. africana acc. MD-20. Duplicated loci were used to identify homoeologous groups. Assignment of linkage groups to the A and B genome was done by comparing the hybridization patterns of probes in Okhale-1, MD-20, and Eleusine indica acc. MD-36. E. indica is the A genome donor to E. coracana. The maps span 721 cM on the A genome and 787 cM on the B genome and cover all 18 finger millet chromosomes, at least partially. To facilitate the use of marker-assisted selection in finger millet, a first set of 82 SSR markers was developed. The SSRs were identified in small-insert genomic libraries generated using methylation-sensitive restriction enzymes. Thirty-one of the SSRs were mapped. Application of the maps and markers in hybridization-based breeding programs will expedite the improvement of finger millet.

  14. Finger Vein Recognition Based on Personalized Weight Maps

    Directory of Open Access Journals (Sweden)

    Lu Yang

    2013-09-01

    Full Text Available Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs. The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition.

  15. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    International Nuclear Information System (INIS)

    Yasumoto, Kyoden; Fujino, Masayuki; Supriyadi; Suzuki, Tetsuya; Hayashi, Toru.

    1991-01-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10 8 /g. Turmeric finger which was irradiated by electron beam at 10 kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10 kGy and 20 kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers. (author)

  16. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    International Nuclear Information System (INIS)

    Yasumoto, K.; Fujino, M.; Supriyadi; Suzuki, T.; Hayashi, T.

    1991-01-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10 8 /g. Turmeric finger which was irradiated by electron beam at 10kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10kGy and 20kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers

  17. Hybrid-Actuated Finger Prosthesis with Tactile Sensing

    Directory of Open Access Journals (Sweden)

    Cheng Yee Low

    2013-10-01

    Full Text Available Finger prostheses are devices developed to emulate the functionality of natural human fingers. On top of their aesthetic appearance in terms of shape, size and colour, such biomimetic devices require a high level of dexterity. They must be capable of gripping an object, and even manipulating it in the hand. This paper presents a biomimetic robotic finger actuated by a hybrid mechanism and integrated with a tactile sensor. The hybrid actuation mechanism comprises a DC micromotor and a Shape Memory Alloy (SMA wire. A customized test rig has been developed to measure the force and stroke produced by the SMA wire. In parallel with the actuator development, experimental investigations have been conducted on Quantum Tunnelling Composite (QTC and Pressure Conductive Rubber (PCR towards the development of a tactile sensor for the finger. The viability of using these materials for tactile sensing has been determined. Such a hybrid actuation approach aided with tactile sensing capability enables a finger design as an integral part of a prosthetic hand for applications up to the transradial amputation level.

  18. Multi-Material Front Contact for 19% Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Joop van Deelen

    2016-02-01

    Full Text Available The trade-off between transmittance and conductivity of the front contact material poses a bottleneck for thin film solar panels. Normally, the front contact material is a metal oxide and the optimal cell configuration and panel efficiency were determined for various band gap materials, representing Cu(In,GaSe2 (CIGS, CdTe and high band gap perovskites. Supplementing the metal oxide with a metallic copper grid improves the performance of the front contact and aims to increase the efficiency. Various front contact designs with and without a metallic finger grid were calculated with a variation of the transparent conductive oxide (TCO sheet resistance, scribing area, cell length, and finger dimensions. In addition, the contact resistance and illumination power were also assessed and the optimal thin film solar panel design was determined. Adding a metallic finger grid on a TCO gives a higher solar cell efficiency and this also enables longer cell lengths. However, contact resistance between the metal and the TCO material can reduce the efficiency benefit somewhat.

  19. Rubber friction: The contribution from the area of real contact.

    Science.gov (United States)

    Tiwari, A; Miyashita, N; Espallargas, N; Persson, B N J

    2018-06-14

    There are two contributions to the friction force when a rubber block is sliding on a hard and rough substrate surface, namely, a contribution F ad = τ f A from the area of real contact A and a viscoelastic contribution F visc from the pulsating forces exerted by the substrate asperities on the rubber block. Here we present experimental results obtained at different sliding speeds and temperatures, and we show that the temperature dependency of the shear stress τ f , for temperatures above the rubber glass transition temperature T g , is weaker than that of the bulk viscoelastic modulus. The physical origin of τ f for T > T g is discussed, and we propose that its temperature dependency is determined by the rubber molecule segment mobility at the sliding interface, which is higher than in the bulk because of increased free-volume effect due to the short-wavelength surface roughness. This is consistent with the often observed reduction in the glass transition temperature in nanometer-thick surface layers of glassy polymers. For temperatures T contact regions and the contact area is determined by the rubber penetration hardness. For this case, we propose that the frictional shear stress is due to slip at the interface between the rubber and a transfer film adsorbed on the concrete surface.

  20. Railway bridge monitoring during construction and sliding

    Science.gov (United States)

    Inaudi, Daniele; Casanova, Nicoletta; Kronenberg, Pascal; Vurpillot, Samuel

    1997-05-01

    The Moesa railway bridge is a composite steel concrete bridge on three spans of 30 m each. The 50 cm thick concrete deck is supported on the lower flanges of two continuous, 2.7 m high I-beams. The bridge has been constructed alongside an old metallic bridge. After demolishing this one, the new bridge has been slid for 5 m by 4 hydraulic jacks and positioned on the refurbished piles of the old bridge. About 30 fiber optic, low-coherence sensors were imbedded in the concrete deck to monitor its deformations during concrete setting and shrinkage, as well as during the bridge sliding phase. In the days following concrete pour it was possible to follow its thermal expansion due to the exothermic setting reaction and the following thermal and during shrinkage. The deformations induced by the additional load produced by the successive concreting phases were also observed. During the bridge push, which extended over six hours, the embedded and surface mounted sensors allowed the monitoring of the curvature variations in the horizontal plane due to the slightly uneven progression of the jacks. Excessive curvature and the resulting cracking of concrete could be ruled out by these measurements. It was also possible to observe the bridge elongation under the heating action of the sun.

  1. Low radiation doses - Book of presentations (slides)

    International Nuclear Information System (INIS)

    2013-03-01

    This document brings together all the available presentations (slides) of the conference on low radiation doses organised by the 'research and health' department of the French society of radiation protection (SFRP). Ten presentations are available and deal with he following topics: 1 - Cyto-toxicity, geno-toxicity: comparative approach between ionizing radiations and other geno-toxic agents (F. Nesslany, Institut Pasteur, Lille); Succession of events occurring after a radio-induced DNA damage (D. Averbeck, IRSN/CEA); Importance of stem cells in the response to ionizing radiations (J. Lebeau, CEA); Relation between energy deposition at the sub-cell scale and early biological effects (C. Villagrasa, IRSN); Natural history of breast cancer: predisposition, susceptibility with respect to irradiation (S. Rivera, IGR); Pediatrics scanner study and the EPI-CT project (M.O Bernier, IRSN); What future for an irradiated cell: survival or apoptosis? (E. Sage, Institut Curie); Differential effect of a 137 Cs chronic contamination on the different steps of the atheromatous pathology (T. Ebrahimian, IRSN); Variability of the individual radiosensitivity (S. Chevillard, CEA); What definitions for individual sensitivity? (A. Schmidt, CEA); Low doses: some philosophical remarks (A. Grinbaum, CEA)

  2. Can slide positivity rates predict malaria transmission?

    Directory of Open Access Journals (Sweden)

    Bi Yan

    2012-04-01

    Full Text Available Abstract Background Malaria is a significant threat to population health in the border areas of Yunnan Province, China. How to accurately measure malaria transmission is an important issue. This study aimed to examine the role of slide positivity rates (SPR in malaria transmission in Mengla County, Yunnan Province, China. Methods Data on annual malaria cases, SPR and socio-economic factors for the period of 1993 to 2008 were obtained from the Center for Disease Control and Prevention (CDC and the Bureau of Statistics, Mengla, China. Multiple linear regression models were conducted to evaluate the relationship between socio-ecologic factors and malaria incidence. Results The results show that SPR was significantly positively associated with the malaria incidence rates. The SPR (β = 1.244, p = 0.000 alone and combination (SPR, β = 1.326, p  Conclusion SPR is a strong predictor of malaria transmission, and can be used to improve the planning and implementation of malaria elimination programmes in Mengla and other similar locations. SPR might also be a useful indicator of malaria early warning systems in China.

  3. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  4. Genome-Wide Identification and Analysis of Genes Encoding PHD-Finger Protein in Tomato

    International Nuclear Information System (INIS)

    Hayat, S.; Cheng, Z.; Chen, X.

    2016-01-01

    The PHD-finger proteins are conserved in eukaryotic organisms and are involved in a variety of important functions in different biological processes in plants. However, the function of PHD fingers are poorly known in tomato (Solanum lycopersicum L.). In current study, we identified 45 putative genes coding Phd finger protein in tomato distributed on 11 chromosomes except for chromosome 8. Some of the genes encode other conserved key domains besides Phd-finger. Phylogenetic analysis of these 45 proteins resulted in seven clusters. Most Phd finger proteins were predicted to PML body location. These PHD-finger genes displayed differential expression either in various organs, at different development stages and under stresses in tomato. Our study provides the first systematic analysis of PHD-finger genes and proteins in tomato. This preliminary study provides a very useful reference information for Phd-finger proteins in tomato. They will be helpful for cloning and functional study of tomato PHD-finger genes. (author)

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ...

  6. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

  7. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Costume Contacts May Contain Chemicals Harmful to Eyes Four Ways Over-the-Counter Costume Contact Lenses Can ... was in severe pain and on medication for four weeks, and couldn't see well enough to ...

  8. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her ...

  9. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados ... truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ...

  10. Colored Contact Lens Dangers

    Science.gov (United States)

    ... Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados ... truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ...

  11. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager ... the lenses. Never share contact lenses with another person. Get follow up exams with your eye care ...

  12. Contact Angle Goniometer

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The FTA32 goniometer provides video-based contact angle and surface tension measurement. Contact angles are measured by fitting a mathematical expression...

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... like a suction cup." Halloween is a popular time for people to use colored contact lenses to ... wear costume contact lenses for Halloween or any time of year, follow these guidelines: Get an eye ...

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... glow-in-the-dark lizard lenses, costume contacts can certainly add a spooky, eye-popping touch. But ... consideration as a standard contact lens because they can be purchased over-the-counter or on the ...

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering ... Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at ...

  16. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ...

  17. Dermatitis, contact (image)

    Science.gov (United States)

    This picture shows a skin inflammation (dermatitis) caused by contact with a material that causes an allergic reaction in this person. Contact dermatitis is a relatively common condition, and can be caused ...

  18. Contact materials for nanoelectronics

    KAUST Repository

    Alshareef, Husam N.; Quevedo-Ló pez, Manuel Angel Quevedo; Majhi, Prashant

    2011-01-01

    In this article, we review current research activities in contact material development for electronic and nanoelectronic devices. A fundamental issue in contact materials research is to understand and control interfacial reactions and phenomena

  19. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... the United States. All contact lenses are medical devices that require a prescription and proper fitting by an eye-care professional. Retailers that sell contacts without a ...

  20. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. Follow the contact lens care directions for cleaning, disinfecting, and wearing the lenses. Never share contact ... with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job Center © American ...

  1. Color standardization and optimization in Whole Slide Imaging

    Directory of Open Access Journals (Sweden)

    Yagi Yukako

    2011-03-01

    Full Text Available Abstract Introduction Standardization and validation of the color displayed by digital slides is an important aspect of digital pathology implementation. While the most common reason for color variation is the variance in the protocols and practices in the histology lab, the color displayed can also be affected by variation in capture parameters (for example, illumination and filters, image processing and display factors in the digital systems themselves. Method We have been developing techniques for color validation and optimization along two paths. The first was based on two standard slides that are scanned and displayed by the imaging system in question. In this approach, one slide is embedded with nine filters with colors selected especially for H&E stained slides (looking like tiny Macbeth color chart; the specific color of the nine filters were determined in our previous study and modified for whole slide imaging (WSI. The other slide is an H&E stained mouse embryo. Both of these slides were scanned and the displayed images were compared to a standard. The second approach was based on our previous multispectral imaging research. Discussion As a first step, the two slide method (above was used to identify inaccurate display of color and its cause, and to understand the importance of accurate color in digital pathology. We have also improved the multispectral-based algorithm for more consistent results in stain standardization. In near future, the results of the two slide and multispectral techniques can be combined and will be widely available. We have been conducting a series of researches and developing projects to improve image quality to establish Image Quality Standardization. This paper discusses one of most important aspects of image quality – color.

  2. Geomorphology, stability and mobility of the Currituck slide

    Science.gov (United States)

    Locat, J.; Lee, H.; ten Brink, Uri S.; Twichell, D.; Geist, E.; Sansoucy, M.

    2009-01-01

    Over the last 100,000??years, the U.S. Atlantic continental margin has experienced various types of mass movements some of which are believed to have taken place at times of low sea level. At one of these times of low sea level a significant trigger caused a major submarine mass movement off the coast of Virginia: the Currituck slide which is believed to have taken place between 24 and 50??ka ago. This slide removed a total volume of about 165??km3 from this section of the continental slope. The departure zone still shows a very clean surface that dips at 4?? and is only covered by a thin veneer of postglacial sediment. Multibeam bathymetric and seismic survey data suggest that this slide took place along three failures surfaces. The morphology of the source area suggests that the sediments were already at least normally consolidated at the time of failure. The slide debris covers an area as much as 55??km wide that extends 180??km from the estimated toe of the original slope. The back analysis of slide initiation indicates that very high pore pressure, a strong earthquake, or both had to be generated to trigger slides on such a low failure plane angle. The shape of the failure plane, the fact that the surface is almost clear of any debris, and the mobility analysis, all support the argument that the slides took place nearly simultaneously. Potential causes for the generation of high pore pressures could be seepage forces from coastal aquifers, delta construction and related pore pressure generation due to the local sediment loading, gas hydrates, and earthquakes. This slide, and its origin, is a spectacular example of the potential threat that submarine mass movements can pose to the US Atlantic coast and underline the need to further assess the potential for the generation of such large slides, like the Grand Banks 1927 landslide of similar volume. ?? 2008 Elsevier B.V.

  3. SurfaceSlide: a multitouch digital pathology platform.

    Directory of Open Access Journals (Sweden)

    Yinhai Wang

    Full Text Available BACKGROUND: Digital pathology provides a digital environment for the management and interpretation of pathological images and associated data. It is becoming increasing popular to use modern computer based tools and applications in pathological education, tissue based research and clinical diagnosis. Uptake of this new technology is stymied by its single user orientation and its prerequisite and cumbersome combination of mouse and keyboard for navigation and annotation. METHODOLOGY: In this study we developed SurfaceSlide, a dedicated viewing platform which enables the navigation and annotation of gigapixel digitised pathological images using fingertip touch. SurfaceSlide was developed using the Microsoft Surface, a 30 inch multitouch tabletop computing platform. SurfaceSlide users can perform direct panning and zooming operations on digitised slide images. These images are downloaded onto the Microsoft Surface platform from a remote server on-demand. Users can also draw annotations and key in texts using an on-screen virtual keyboard. We also developed a smart caching protocol which caches the surrounding regions of a field of view in multi-resolutions thus providing a smooth and vivid user experience and reducing the delay for image downloading from the internet. We compared the usability of SurfaceSlide against Aperio ImageScope and PathXL online viewer. CONCLUSION: SurfaceSlide is intuitive, fast and easy to use. SurfaceSlide represents the most direct, effective and intimate human-digital slide interaction experience. It is expected that SurfaceSlide will significantly enhance digital pathology tools and applications in education and clinical practice.

  4. Comparing whole slide digital images versus traditional glass slides in the detection of common microscopic features seen in dermatitis

    Directory of Open Access Journals (Sweden)

    Nikki S Vyas

    2016-01-01

    Full Text Available Background: The quality and limitations of digital slides are not fully known. We aimed to estimate intrapathologist discrepancy in detecting specific microscopic features on glass slides and digital slides created by scanning at ×20. Methods: Hematoxylin and eosin and periodic acid-Schiff glass slides were digitized using the Mirax Scan (Carl Zeiss Inc., Germany. Six pathologists assessed 50-71 digital slides. We recorded objective magnification, total time, and detection of the following: Mast cells; eosinophils; plasma cells; pigmented macrophages; melanin in the epidermis; fungal bodies; neutrophils; civatte bodies; parakeratosis; and sebocytes. This process was repeated using the corresponding glass slides after 3 weeks. The diagnosis was not required. Results: The mean time to assess digital slides was 176.77 s and 137.61 s for glass slides (P < 0.001, 99% confidence interval [CI]. The mean objective magnification used to detect features using digital slides was 18.28 and 14.07 for glass slides (P < 0.001, 99.99% CI. Parakeratosis, civatte bodies, pigmented macrophages, melanin in the epidermis, mast cells, eosinophils, plasma cells, and neutrophils, were identified at lower objectives on glass slides (P = 0.023-0.001, 95% CI. Average intraobserver concordance ranged from κ = 0.30 to κ = 0.78. Features with poor to fair average concordance were: Melanin in the epidermis (κ = 0.15-0.58; plasma cells (κ = 0.15-0.49; and neutrophils (κ = 0.12-0.48. Features with moderate average intrapathologist concordance were: parakeratosis (κ = 0.21-0.61; civatte bodies (κ = 0.21-0.71; pigment-laden macrophages (κ = 0.34-0.66; mast cells (κ = 0.29-0.78; and eosinophils (κ = 0.31-0.79. The average intrapathologist concordance was good for sebocytes (κ = 0.51-1.00 and fungal bodies (κ = 0.47-0.76. Conclusions: Telepathology using digital slides scanned at ×20 is sufficient for detection of histopathologic features routinely encountered in

  5. Fingering in a channel and tripolar Loewner evolutions

    Science.gov (United States)

    Durán, Miguel A.; Vasconcelos, Giovani L.

    2011-11-01

    A class of Laplacian growth models in the channel geometry is studied using the formalism of tripolar Loewner evolutions, in which three points, namely, the channel corners and the point at infinity, are kept fixed. Initially, the problem of fingered growth, where growth takes place only at the tips of slitlike fingers, is revisited and a class of exact solutions of the corresponding Loewner equation is presented for the case of stationary driving functions. A model for interface growth is then formulated in terms of a generalized tripolar Loewner equation and several examples are presented. It is shown that the growing interface evolves into a steadily moving finger and that tip competition arises for nonsymmetric initial configurations with multiple tips.

  6. Finger Vein Recognition Based on a Personalized Best Bit Map

    Science.gov (United States)

    Yang, Gongping; Xi, Xiaoming; Yin, Yilong

    2012-01-01

    Finger vein patterns have recently been recognized as an effective biometric identifier. In this paper, we propose a finger vein recognition method based on a personalized best bit map (PBBM). Our method is rooted in a local binary pattern based method and then inclined to use the best bits only for matching. We first present the concept of PBBM and the generating algorithm. Then we propose the finger vein recognition framework, which consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PBBM achieves not only better performance, but also high robustness and reliability. In addition, PBBM can be used as a general framework for binary pattern based recognition. PMID:22438735

  7. Effect of transcranial magnetic stimulation on force of finger pinch

    Science.gov (United States)

    Odagaki, Masato; Fukuda, Hiroshi; Hiwaki, Osamu

    2009-04-01

    Transcranial magnetic stimulation (TMS) is used to explore many aspects of brain function, and to treat neurological disorders. Cortical motor neuronal activation by TMS over the primary motor cortex (M1) produces efferent signals that pass through the corticospinal tracts. Motor-evoked potentials (MEPs) are observed in muscles innervated by the stimulated motor cortex. TMS can cause a silent period (SP) following MEP in voluntary electromyography (EMG). The present study examined the effects of TMS eliciting MEP and SP on the force of pinching using two fingers. Subjects pinched a wooden block with the thumb and index finger. TMS was applied to M1 during the pinch task. EMG of first dorsal interosseous muscles and pinch forces were measured. Force output increased after the TMS, and then oscillated. The results indicated that the motor control system to keep isotonic forces of the muscles participated in the finger pinch was disrupted by the TMS.

  8. Compensating Pose Uncertainties through Appropriate Gripper Finger Cutouts

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Gams, Andrej; Kiforenko, Lilita

    2018-01-01

    The gripper finger design is a recurring problem in many robotic grasping platforms used in industry. The task of switching the gripper configuration to accommodate a new batch of objects typically requires engineering expertise and is a lengthy and costly iterative trial-and-error process. One...... in a sample industrial object grasping scenario for a finger that was designed using an automated simulation-based geometry optimization method (Wolniakowski et al., 2013, 2015). We test the developed gripper with a set of grasps subjected to structured perturbation in a simulation environment and in the real......-world setting. We provide a comparison of the data obtained by using both of these approaches. We argue that the strong correspondence observed in results validates the use of dynamic simulation for the gripper finger design and optimization....

  9. Finger vein recognition based on convolutional neural network

    Directory of Open Access Journals (Sweden)

    Meng Gesi

    2017-01-01

    Full Text Available Biometric Authentication Technology has been widely used in this information age. As one of the most important technology of authentication, finger vein recognition attracts our attention because of its high security, reliable accuracy and excellent performance. However, the current finger vein recognition system is difficult to be applied widely because its complicated image pre-processing and not representative feature vectors. To solve this problem, a finger vein recognition method based on the convolution neural network (CNN is proposed in the paper. The image samples are directly input into the CNN model to extract its feature vector so that we can make authentication by comparing the Euclidean distance between these vectors. Finally, the Deep Learning Framework Caffe is adopted to verify this method. The result shows that there are great improvements in both speed and accuracy rate compared to the previous research. And the model has nice robustness in illumination and rotation.

  10. Trigger finger presenting secondary to leiomyoma: a case report

    Directory of Open Access Journals (Sweden)

    Harb Ziad

    2009-05-01

    Full Text Available Abstract Introduction We present a previously undescribed entity: trigger finger secondary to a leiomyoma. This is the first time such a case has been reported and highlights the fact that common conditions can sometimes present secondary to rare diseases. Case presentation A 39-year-old Caucasian man presented with a fairly typical presentation of trigger finger. During surgical treatment, the lesion was excised and sent for histology, which showed tissue consistent with a leiomyoma. The patient made an uneventful recovery. Conclusion Trigger finger is a common condition that is usually easily diagnosed and managed. However, it is important to appreciate that uncommon conditions, such as leiomyoma, can present with what is sometimes considered trivial disease, and one should always consider the differential diagnoses even when faced with relatively benign conditions.

  11. Robust synchronization of unified chaotic systems via sliding mode control

    International Nuclear Information System (INIS)

    Yan Junjuh; Yang Yisung; Chiang Tsungying; Chen Chingyuan

    2007-01-01

    This paper investigates the chaos synchronization problem for a class of uncertain master-slave unified chaotic systems. Based on the sliding mode control technique, a robust control scheme is established which guarantees the occurrence of a sliding motion of error states even when the parameter uncertainty and external perturbation are present. Furthermore, a novel proportional-integral (PI) switching surface is introduced for determining the synchronization performance of systems in the sliding mode motion. Simulation results are proposed to demonstrate the effectiveness of the method

  12. Sliding Mode Attitude Control for Magnetic Actuated Satellite

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    1998-01-01

    control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis attitude control. This paper deals with three-axis stabilization of a low earth orbit satellite. The problem of controlling...... the spacecraft attitude using only magnetic torquing is realized in the form of the sliding mode control. A three dimensional sliding manifold is proposed, and it is shown that the satellite motion on the sliding manifold is asymptotically stable...

  13. Contact Lens Risks

    Science.gov (United States)

    ... There is a risk of eye infection from bacteria in swimming pool water, hot tubs, lakes and the ocean Replace your contact lens storage case every 3 months or as directed by your eye care professional. Other Risks of Contact Lenses Other risks of contact lenses include pink eye ( ...

  14. Hydrogenation of passivated contacts

    Energy Technology Data Exchange (ETDEWEB)

    Nemeth, William; Yuan, Hao-Chih; LaSalvia, Vincenzo; Stradins, Pauls; Page, Matthew R.

    2018-03-06

    Methods of hydrogenation of passivated contacts using materials having hydrogen impurities are provided. An example method includes applying, to a passivated contact, a layer of a material, the material containing hydrogen impurities. The method further includes subsequently annealing the material and subsequently removing the material from the passivated contact.

  15. Mixed Lubricated Line Contacts

    NARCIS (Netherlands)

    Faraon, I.C.

    2005-01-01

    The present work deals with friction in mixed lubricated line contacts. Components in systems are becoming smaller and due to, for instance power transmitted, partial contact may occur. In industrial applications, friction between the moving contacting surfaces cannot be avoided, therefore it is

  16. New Cosmetic Contact Allergens

    Directory of Open Access Journals (Sweden)

    An Goossens

    2015-02-01

    Full Text Available Allergic and photo-allergic contact dermatitis, and immunologic contact urticaria are potential immune-mediated adverse effects from cosmetics. Fragrance components and preservatives are certainly the most frequently observed allergens; however, all ingredients must be considered when investigating for contact allergy.

  17. The influence of intrinsic sympathomimetic activity and beta-1 receptor selectivity on the recovery of finger skin temperature after finger cooling in normotensive subjects.

    Science.gov (United States)

    Lenders, J W; Salemans, J; de Boo, T; Lemmens, W A; Thien, T; van't Laar, A

    1986-03-01

    A double-blind randomized study was designed to investigate differences in the recovery of finger skin temperature after finger cooling during dosing with placebo or one of four beta-blockers: propranolol, atenolol, pindolol, and acebutolol. In 11 normotensive nonsmoking subjects, finger skin temperature was measured with a thermocouple before and 20 minutes after immersion of one hand in a water bath at 16 degrees C. This finger cooling test caused no significant changes in systemic hemodynamics such as arterial blood pressure, heart rate, and forearm blood flow. The recovery of finger skin temperature during propranolol dosing was better than that during pindolol and atenolol dosing. There were no differences between the recoveries of skin temperature during pindolol, atenolol, and acebutolol dosing. Thus we could demonstrate no favorable effect of intrinsic sympathomimetic activity or beta 1-selectivity on the recovery of finger skin temperature after finger cooling.

  18. Viscous fingering effects in solvent displacement of heavy oil

    Energy Technology Data Exchange (ETDEWEB)

    Cuthiell, D. [Suncor Energy, Fort McMurray, AB (Canada); Kissel, G.; Jackson, C.; Frauenfeld, T.W.J.; Fisher, D. [Alberta Research Council, Devon, AB (Canada); Rispler, K. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2004-07-01

    Vapour Extraction (VAPEX) is a solvent-based process that is analogous to steam-assisted gravity drainage (SAGD) for the recovery of heavy oil. A cyclic solvent process is preferred for thin reservoirs, particularly primary-depleted reservoirs. In a cyclic steam stimulation process, a solvent is injected into the reservoir for a period of time before oil is produced from the well. Viscous fingering is a phenomena that characterizes several solvent-based processes for the recovery of heavy oil. A combined experimental and simulation study was conducted to characterize viscous fingering under heavy oil recovery conditions (high ratio of oil to solvent viscosity). Four experiments were conducted in heavy oil-saturated sand packs. Three involved injection of a miscible, liquid solvent at the bottom of the sand pack. The heavy oil in these experiments was displaced upwardly. The fourth experiment involved top-down injection of a gaseous solvent. The miscible liquid displacement was dominated by one solvent finger which broke through to a producing well at the other end of the sand pack. Breakthrough times were similar to that at lower viscosity. The fourth experiment showed fingering along with features of a gravity-driven VAPEX process. Key features of the experiment and realistic fingering patterns were numerically simulated using a commercial reservoir simulator. It was emphasized that accurate modelling of dispersion is necessary in matching the observed phenomena. The simulations should include the capillary effects because of their significance for gaseous fingering and the VAPEX processes. 17 refs., 2 tabs., 20 figs.

  19. Magnetic resonance imaging and radiographic findings of seal finger

    International Nuclear Information System (INIS)

    Marjelund, S.; Tikkakoski, T.; Isokangas, M.; Raeisaenen, S.

    2006-01-01

    Purpose: To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger. Material and Methods: The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously. Results: Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen. Conclusion: In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography

  20. Magnetic resonance imaging and radiographic findings of seal finger

    Energy Technology Data Exchange (ETDEWEB)

    Marjelund, S.; Tikkakoski, T.; Isokangas, M.; Raeisaenen, S. [Oulu Univ. Hospital (Finland). Dept. of Radiology

    2006-12-15

    Purpose: To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger. Material and Methods: The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously. Results: Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen. Conclusion: In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography.