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Sample records for hand transmitted vibration

  1. Measurement, evaluation, and assessment of occupational exposures to hand-transmitted vibration.

    PubMed Central

    Griffin, M J

    1997-01-01

    The measurement of hand-transmitted vibration converts oscillatory movements to a form in which they can be evaluated with respect to human responses and assessed for their acceptability. This paper presents methods of measurement, evaluation, and assessment currently advocated in standards and other forms of guidance. The degree to which the methods of evaluating different frequencies, directions, and durations of vibration affect the assessment of vibration on different tools is illustrated. With the frequency weighting currently used to allow for the effects of different frequencies there is little need to measure vibration at frequencies as high as 1000 Hz; this has significant implications to the design and evaluation of proposed antivibration devices, including gloves. Without the current frequency weighting, vibration at frequencies greater than 250 Hz can contribute to the magnitude of the vibration, but many common causes of injury from hand-transmitted vibration have their dominant components of vibration below 250 Hz. On many powered tools, although the dominant frequency of vibration is the same before and after frequency weighting, the reported magnitude of vibration is greatly affected by the frequency weighting. On tools with dominant low frequencies, their vibration is rated as being of far greater importance relative to other tools when considering frequency-weighted acceleration than when considering unweighted acceleration. It is shown that the effect of considering three axes of vibration as opposed to one axis has a greater effect on some tools than on others. The uncertainties and assumptions involved in the measurement, evaluation, and assessment of hand-transmitted vibration are reviewed. It is suggested that whereas current decisions on health and welfare should be based on current assessment methods, the measurement and evaluation of hand-transmitted vibration should involve the collection and reporting of data which allow other

  2. Haemodynamic changes in ipsilateral and contralateral fingers caused by acute exposures to hand transmitted vibration.

    PubMed Central

    Bovenzi, M; Griffin, M J

    1997-01-01

    OBJECTIVES: To investigate changes in digital circulation during and after exposure to hand transmitted vibration. By studying two frequencies and two magnitudes of vibration, to investigate the extent to which haemodynamic changes depend on the vibration frequency, the vibration acceleration, and the vibration velocity. METHODS: Finger skin temperature (FST), finger blood flow (FBF), and finger systolic pressure were measured in the fingers of both hands in eight healthy men. Indices of digital vasomotor tone-such as critical closing pressure and vascular resistance-were estimated by pressure-flow curves obtained with different hand heights. With a static load of 10 N, the right hand was exposed for 30 minutes to each of the following root mean squared (rms) acceleration magnitudes and frequencies of vertical vibration: 22 m.s-2 at 31.5 Hz, 22 m.s-2 at 125 Hz, and 87 m.s-2 at 125 Hz. A control condition consisted of exposure to the static load only. The measures of digital circulation and vasomotor tone were taken before exposure to the vibration and the static load, and at 0, 20, 40, and 60 minutes after the end of each exposure. RESULTS: Exposure to static load caused no significant changes in FST, FBF, or indices of vasomotor tone in either the vibrated right middle finger or the non-vibrated left middle finger. In both fingers, exposure to vibration of 125 Hz and 22 m.s-2 produced a greater reduction in FBF and a greater increase in vasomotor tone than did vibration of 31.5 Hz and 22 m.s-2. In the vibrated right finger, exposure to vibration of 125 Hz and 87 m.s-2 provoked an immediate vasodilation which was followed by vasoconstriction during recovery. The non-vibrated left finger showed a significant increase in vasomotor tone throughout the 60 minute period after the end of vibration exposure. CONCLUSIONS: The digital circulatory response to acute vibration depends upon the magnitude and frequency of the vibration stimulus. Vasomotor mechanisms, mediated

  3. Human hand-transmitted vibration measurements on pedestrian controlled tractor operators by a laser scanning vibrometer.

    PubMed

    Deboli, R; Miccoli, G; Rossi, G L

    1999-06-01

    A first application of a new measurement technique to detect vibration transmitted to the human body in working conditions is presented. The technique is based on the use of a laser scanning vibrometer. It was previously developed, analysed and tested using laboratory test benches with electrodynamical exciters, and comparisons with traditional measurement techniques based on accelerometers were made. First, results of tests performed using a real machine generating vibration are illustrated. The machine used is a pedestrian-controlled tractor working in a fixed position. Reference measurements by using the accelerometer have been simultaneously performed while scanning the hand surface by the laser-based measurement system. Results achieved by means of both measurement techniques have been processed, analysed, compared and used to calculate transmissibility maps of the hands of three subjects. PMID:10340028

  4. Development of a hand- transmitted vibration measurement instrument to perform tests in medical equipment according to the international standard IEC 60601-1-2005 Ed.3

    NASA Astrophysics Data System (ADS)

    de Lima, F. F.; Moriya, H. T.; Moraes, J. C. T. B.

    2016-07-01

    According to the sub clause 9.6.3 of the international standard IEC 60601-1-2005, medical electrical equipment must provide means of protection against hazardous hand- transmitted vibrations. Compliance of this sub clause is checked by using a vibration measurement instrument in accordance with ISO 5349-1-2001 standard. The present article describes the development of a vibration measurement instrument to perform vibration measurements tests in medical equipments.

  5. Tool-specific performance of vibration-reducing gloves for attenuating palm-transmitted vibrations in three orthogonal directions

    PubMed Central

    Dong, Ren G.; Welcome, Daniel E.; Peterson, Donald R.; Xu, Xueyan S.; McDowell, Thomas W.; Warren, Christopher; Asaki, Takafumi; Kudernatsch, Simon; Brammer, Antony

    2015-01-01

    Vibration-reducing (VR) gloves have been increasingly used to help reduce vibration exposure, but it remains unclear how effective these gloves are. The purpose of this study was to estimate tool-specific performances of VR gloves for reducing the vibrations transmitted to the palm of the hand in three orthogonal directions (3-D) in an attempt to assess glove effectiveness and aid in the appropriate selection of these gloves. Four typical VR gloves were considered in this study, two of which can be classified as anti-vibration (AV) gloves according to the current AV glove test standard. The average transmissibility spectrum of each glove in each direction was synthesized based on spectra measured in this study and other spectra collected from reported studies. More than seventy vibration spectra of various tools or machines were considered in the estimations, which were also measured in this study or collected from reported studies. The glove performance assessments were based on the percent reduction of frequency-weighted acceleration as is required in the current standard for assessing the risk of vibration exposures. The estimated tool-specific vibration reductions of the gloves indicate that the VR gloves could slightly reduce (<5%) or marginally amplify (<10%) the vibrations generated from low-frequency (<25 Hz) tools or those vibrating primarily along the axis of the tool handle. With other tools, the VR gloves could reduce palm-transmitted vibrations in the range of 5%–58%, primarily depending on the specific tool and its vibration spectra in the three directions. The two AV gloves were not more effective than the other gloves with some of the tools considered in this study. The implications of the results are discussed. Relevance to industry Hand-transmitted vibration exposure may cause hand-arm vibration syndrome. Vibration-reducing gloves are considered as an alternative approach to reduce the vibration exposure. This study provides useful information

  6. Vibration transmissibility characteristics of the human hand-arm system under different postures, hand forces and excitation levels

    NASA Astrophysics Data System (ADS)

    Adewusi, S. A.; Rakheja, S.; Marcotte, P.; Boutin, J.

    2010-07-01

    Biodynamic responses of the hand-arm system have been mostly characterized in terms of driving-point force-motion relationships, which have also served as the primary basis for developing the mechanical-equivalent models. The knowledge of localized vibration responses of the hand-arm segments could help derive more effective biodynamic models. In this study, the transmission of z h-axis handle vibration to the wrist, elbow and the shoulder of the human hand and arm are characterized in the laboratory for the bent-arm and extended arm postures. The experiments involved six subjects grasping a handle subject to two different magnitudes of broad-band random vibration, and nine different combinations of hand grip and push forces. The vibration transmissibility data were acquired in the z h- and y h-axis at the wrist and shoulder, and along all the three axes around the elbow joint. The results show that the human hand-arm system in an extended arm posture amplifies the vibration transmitted to the upper-arm and the whole-body at frequencies below 25 Hz, but attenuates the vibration above 25 Hz more effectively than the bent-arm posture, except at the shoulder. The magnitudes of transmitted vibration under an extended arm posture along the y h-axis were observed to be nearly twice those for the bent-arm posture in the low frequency region. The results further showed that variations in the grip force mostly affect vibration transmissibility and characteristic frequencies of the forearm, while changes in the push force influenced the dynamic characteristics of the entire hand-arm system. The magnitudes of transmitted vibration in the vicinity of the characteristic frequencies were influenced by the handle vibration magnitude.

  7. Vascular hand-arm vibration syndrome--magnetic resonance angiography.

    PubMed

    Poole, C J M; Cleveland, T J

    2016-01-01

    The diagnosis of vascular hand-arm vibration syndrome (HAVS) requires consistent symptoms, photographic evidence of digital blanching and sufficient exposure to hand-transmitted vibration (HTV; A(8) > 2.5 m/s2). There is no reliable quantitative investigation for distinguishing HAVS from other causes of Raynaud's phenomenon and from normal individuals. Hypothenar and thenar hammer syndromes produce similar symptoms to HAVS but are difficult to diagnose clinically and may be confused with HAVS. Magnetic resonance angiography (MRA) is a safe and minimally invasive method of visualizing blood vessels. Three cases of vascular HAVS are described in which MRA revealed occlusions of the ulnar, radial and superficial palmar arteries. It is proposed that HTV was the cause of these occlusions, rather than blows to the hand unrelated to vibration, the assumed mechanism for the hammer syndromes. All three cases were advised not to expose their hands to HTV despite one of them being at Stockholm vascular stage 2 (early). MRA should be the investigation of choice for stage 2 vascular HAVS or vascular HAVS with unusual features or for a suspected hammer syndrome. The technique is however technically challenging and best done in specialist centres in collaboration with an occupational physician familiar with the examination of HAVS cases. Staging for HAVS should be developed to include anatomical arterial abnormalities as well as symptoms and signs of blanching. Workers with only one artery supplying a hand, or with only one palmar arch, may be at increased risk of progression and therefore should not be exposed to HTV irrespective of their Stockholm stage. PMID:26470947

  8. Improved method for minimizing vibrational motion transmitted by pumping lines.

    PubMed

    Kirk, W P; Twerdochlib, M

    1978-06-01

    A description is given for a technique that is very effective in reducing vibrations transmitted along large-diameter ( greater, similar8 cm) vacuum and gas pumping lines. This technique uses a supported double-gimbal metal bellows design. When compared with other techniques such as the crossed T metal bellows design, a factor of 7 improvement was measured. An analysis is included which compares the various techniques, and shows that, in principle, improvement factors as high as 80 or more can be realized with the double-gimbal design. PMID:18699187

  9. An examination of an adapter method for measuring the vibration transmitted to the human arms

    PubMed Central

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

    2016-01-01

    The objective of this study is to evaluate an adapter method for measuring the vibration on the human arms. Four instrumented adapters with different weights were used to measure the vibration transmitted to the wrist, forearm, and upper arm of each subject. Each adapter was attached at each location on the subjects using an elastic cloth wrap. Two laser vibrometers were also used to measure the transmitted vibration at each location to evaluate the validity of the adapter method. The apparent mass at the palm of the hand along the forearm direction was also measured to enhance the evaluation. This study found that the adapter and laser-measured transmissibility spectra were comparable with some systematic differences. While increasing the adapter mass reduced the resonant frequency at the measurement location, increasing the tightness of the adapter attachment increased the resonant frequency. However, the use of lightweight (≤15 g) adapters under medium attachment tightness did not change the basic trends of the transmissibility spectrum. The resonant features observed in the transmissibility spectra were also correlated with those observed in the apparent mass spectra. Because the local coordinate systems of the adapters may be significantly misaligned relative to the global coordinates of the vibration test systems, large errors were observed for the adapter-measured transmissibility in some individual orthogonal directions. This study, however, also demonstrated that the misalignment issue can be resolved by either using the total vibration transmissibility or by measuring the misalignment angles to correct the errors. Therefore, the adapter method is acceptable for understanding the basic characteristics of the vibration transmission in the human arms, and the adapter-measured data are acceptable for approximately modeling the system. PMID:26834309

  10. An examination of the vibration transmissibility of the hand-arm system in three orthogonal directions

    PubMed Central

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

    2015-01-01

    The objective of this study is to enhance the understanding of the vibration transmission in the hand-arm system in three orthogonal directions (X, Y, and Z). For the first time, the transmitted vibrations distributed on the entire hand-arm system exposed in the three orthogonal directions via a 3-D vibration test system were measured using a 3-D laser vibrometer. Seven adult male subjects participated in the experiment. This study confirms that the vibration transmissibility generally decreased with the increase in distance from the hand and it varied with the vibration direction. Specifically, to the upper arm and shoulder, only moderate vibration transmission was measured in the test frequency range (16 to 500 Hz), and virtually no transmission was measured in the frequency range higher than 50 Hz. The resonance vibration on the forearm was primarily in the range of 16–30 Hz with the peak amplitude of approximately 1.5 times of the input vibration amplitude. The major resonance on the dorsal surfaces of the hand and wrist occurred at around 30–40 Hz and, in the Y direction, with peak amplitude of more than 2.5 times of the input amplitude. At higher than 50 Hz, vibration transmission was effectively limited to the hand and fingers. A major finger resonance was observed at around 100 Hz in the X and Y directions and around 200 Hz in the Z direction. In the fingers, the resonance magnitude in the Z direction was generally the lowest, and the resonance magnitude in the Y direction was generally the highest with the resonance amplitude of 3 times the input vibration, which was similar to the transmissibility at the wrist and hand dorsum. The implications of the results are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration could result in hand-arm vibration syndrome. While the syndrome's precise mechanisms remain unclear, the characterization of the vibration transmissibility of the system in the three orthogonal

  11. Assessing the influence of antivibration glove on digital vascular responses to acute hand-arm vibration.

    PubMed

    Mahbub, Md H; Yokoyama, Kenjiro; Laskar, Md S; Inoue, Masaiwa; Takahashi, Yukio; Yamamoto, Shinji; Harada, Noriaki

    2007-05-01

    This study was designed to assess the influence of an antivibration glove on digital vascular responses in healthy subjects exposed to short-term grasping of a vibrating handle. To measure finger blood flow (FBF) and finger skin temperature (FST) once at the end of every min, a blood flowmeter sensor was attached to the dorsum and a thermistor sensor was attached to the medial surface of the subject's middle phalanx of the third finger of the right hand. After 5 min of baseline measurements without or with an antivibration glove meeting ISO standard 10819, worn on the right hand, subjects gripped a vibrating handle with the same hand for a period of 5 min. Vibration was generated at two frequencies of 31.5 Hz and 250 Hz with a frequency weighted rms acceleration of 5.5 m/s(2). FBF and FST continued to be recorded for a further 5 min after release of the vibrating handle. Statistical analysis showed no significant change after vibration exposure in either FST or FBF at 250 Hz, compared to baseline (control) measurements while using the antivibration glove. At 31.5 Hz, FBF data exhibited a significant difference between before and after grasping of vibrating handle, which was less under the condition of wearing the antivibration glove than under the condition of bare hand. The results provide evidence that the antivibration glove considerably influenced finger vascular changes in healthy subjects induced by vibration exposure, especially against high frequency vibration. Further studies are required to assess finger vascular responses to hand-transmitted vibration with antivibration gloves of different manufacturers. PMID:17575396

  12. [Hand-arm vibration syndrome and upper limbs diseases in the forest workers of Italia meridionale].

    PubMed

    Fenga, C; Rapisarda, V; Valentino, M; Cacciola, A; Deboli, R; Calvo, A; Germanò, D

    2007-01-01

    Vibration exposure of the hand-arm system is associated with an increased risk of upper-limb vascular, neurological and musculoskeletal lesions, or hand-arm vibration syndrome (HAVS). The prevalence of occupational HAVS and upper-limb disorders was studied among 278 Forestry Service workers in Sicily and Calabria. Subjects who used chain-saws (18 weeks/year) had a greater prevalence of peripheral sensory-neural disturbances (28%), upper-limb musculoskeletal disorders (33%) and carpal tunnel syndrome (19%) compared with 260 manual workers from the same Corps not exposed to hand-transmitted vibration. Raynaud's phenomenon was comparable in exposed and control subjects (5.3% vs. 4.7%.) Upper-limb neuropathies were significantly associated with energy-equivalent frequency-weighted acceleration; exposure duration; and cumulative vibration dose (m2/s4h). The variable "years of work with vibrating tools" was strongly associated with peripheral neuropathies; carpal tunnel syndrome; and upper-limb musculotendinous syndromes. Data suggest that in Sicily and Calabria, where the climate is milder than in other areas of Italy, forestry work with hand-held vibrating tools does not entail a greater prevalence of peripheral vascular disorders (Raynaud's phenomenon), while the prevalence of occupational upper-limb neurological and musculoskeletal disorders, in which combined ergonomic and mechanical risk factors have a large pathogenic role, is significantly increased. PMID:18409849

  13. Spatial patterns of cutaneous vibration during whole-hand haptic interactions.

    PubMed

    Shao, Yitian; Hayward, Vincent; Visell, Yon

    2016-04-12

    We investigated the propagation patterns of cutaneous vibration in the hand during interactions with touched objects. Prior research has highlighted the importance of vibrotactile signals during haptic interactions, but little is known of how vibrations propagate throughout the hand. Furthermore, the extent to which the patterns of vibrations reflect the nature of the objects that are touched, and how they are touched, is unknown. Using an apparatus comprised of an array of accelerometers, we mapped and analyzed spatial distributions of vibrations propagating in the skin of the dorsal region of the hand during active touch, grasping, and manipulation tasks. We found these spatial patterns of vibration to vary systematically with touch interactions and determined that it is possible to use these data to decode the modes of interaction with touched objects. The observed vibration patterns evolved rapidly in time, peaking in intensity within a few milliseconds, fading within 20-30 ms, and yielding interaction-dependent distributions of energy in frequency bands that span the range of vibrotactile sensitivity. These results are consistent with findings in perception research that indicate that vibrotactile information distributed throughout the hand can transmit information regarding explored and manipulated objects. The results may further clarify the role of distributed sensory resources in the perceptual recovery of object attributes during active touch, may guide the development of approaches to robotic sensing, and could have implications for the rehabilitation of the upper extremity. PMID:27035957

  14. Vibration and impulsivity analysis of hand held olive beaters.

    PubMed

    Deboli, Roberto; Calvo, Angela; Preti, Christian

    2016-07-01

    To provide more effective evaluations of hand arm vibration syndromes caused by hand held olive beaters, this study focused on two aspects: the acceleration measured at the tool pole and the analysis of the impulsivity, using the crest factor. The signals were frequency weighted using the weighting curve Wh as described in the ISO 5349-1 standard. The same source signals were also filtered by the Wh-bl filter (ISO/TS 15694), because the weighting filter Wh (unlike the Wh-bl filter) could underestimate the effect of high frequency vibration on vibration-induced finger disorders. Ten (experienced) male operators used three beater models (battery powered) in the real olive harvesting condition. High vibration total values were obtained with values never lower than 20 m(-2). Concerning the crest factor, the values ranged from 5 to more than 22. This work demonstrated that the hand held olive beaters produced high impulsive loads comparable to the industry hand held tools. PMID:26615333

  15. Thermal and vibration testing of ruggedized IR-transmitting fiber cables

    NASA Astrophysics Data System (ADS)

    Busse, Lynda; Kung, Fred; Florea, Catalin; Shaw, Brandon; Aggarwal, Ishwar; Sanghera, Jas

    2013-05-01

    We present successful results obtained for thermal/ vibration testing of ruggedized, IR-transmitting chalcogenide glass fiber cables using a government facility with state-of-the-art equipment capable of MIL-SPEC environmental testing. We will also present results of a direct imprinting process to create novel "moth eye" patterned surfaces on the IR fiber cable ends that significantly reduces endface reflection losses from 17% to less than 3%. The cables with these imprinted "moth eye" ends transmit much higher IR laser power without damage than was obtained for previous cables with traditional AR coatings.

  16. Lessons from hand-arm vibration syndrome research.

    PubMed

    Wasserman, D E; Taylor, W

    1991-01-01

    This paper addresses many of the salient issues and difficulties encountered in performing Hand-Arm Vibration Syndrome research since its discovery in the early 1900's by Alice Hamilton. The areas discussed and the resulting lessons learned include the medical, epidemiological, and control aspects of HAVS. The authors conclude with a plea to health professionals to be ever vigilant and responsive to the HAVS problem, or else it will continue unabated into the next century, an overall time span of nearly 100 years. PMID:2035552

  17. Proposal of a new measurement technique for hand-arm vibration analysis

    NASA Astrophysics Data System (ADS)

    Rossi, Gianluca L.; Tomasini, Enrico P.

    1994-09-01

    In this paper a new measurement technique to analyze hand-arm vibration is proposed. The methodology is based on a laser scanning vibrometer, a new instrument that measures, without contact, vibration on grid points on a surface. The technique can be applied in laboratory tests and also to perform in field tests on hand-guided vibrating tools, vehicles, machine. Tests with sinusoidal vibrations up to 250 Hz have been performed on different subjects with their hand on three test devices, designed accordingly to ISO standards, has been used to verify the measurement technique. Further work has been started in order to develop a measurement system for mapping the mechanical impedance measurements in some points of the hand of different subjects are illustrated. These techniques prove to be very powerful to analyze hand-arm dynamic characteristics.

  18. A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the win

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the wingtip of the Active Aeroelastic Wing F/A-18 research aircraft during ground vibration testing at NASA's Dryden Flight Research Center. Wiring hanging down from the wingtip launcher rail transfer signals from accelerometers and other sensors mounted on the wing's upper surface to monitoring equipment. The tests help engineers determine if aerodynamically induced vibrations are controlled or suppressed during flight, and were the last major ground tests prior to the initiation of research flights.

  19. Control Model for Dampening Hand Vibrations Using Information of Internal and External Coordinates

    PubMed Central

    Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

    2015-01-01

    In the present study, we investigate a control mechanism that dampens hand vibrations. Here, we propose a control method with two components to suppress hand vibrations. The first is a passive suppression method that lowers the joint stiffness to passively dampen the hand vibrations. The second is an active suppression method that adjusts an equilibrium point based on skyhook control to actively dampen the hand vibrations. In a simulation experiment, we applied these two methods to dampen hand vibrations during the shoulder’s horizontal oscillation. We also conducted a measurement experiment wherein a subject’s shoulder was sinusoidally oscillated by a platform that generated horizontal oscillations. The results of the measurement experiments showed that the jerk of each part of the arm in a task using a cup filled with water was smaller than the shoulder jerk and that in a task with a cup filled with stones was larger than the shoulder jerk. Moreover, the amplitude of the hand trajectory in both horizontal and vertical directions was smaller in a task using a cup filled with water than in a task using a cup filled with stones. The results of the measurement experiments were accurately reproduced by the active suppression method based on skyhook control. These results suggest that humans dampen hand vibrations by controlling the equilibrium point through the information of the external workspace and the internal body state rather than by lowering joint stiffness only by using internal information. PMID:25876037

  20. Validity and inter-observer reliability of subjective hand-arm vibration assessments.

    PubMed

    Coenen, Pieter; Formanoy, Margriet; Douwes, Marjolein; Bosch, Tim; de Kraker, Heleen

    2014-07-01

    Exposure to mechanical vibrations at work (e.g., due to handling powered tools) is a potential occupational risk as it may cause upper extremity complaints. However, reliable and valid assessment methods for vibration exposure at work are lacking. Measuring hand-arm vibration objectively is often difficult and expensive, while often used information provided by manufacturers lacks detail. Therefore, a subjective hand-arm vibration assessment method was tested on validity and inter-observer reliability. In an experimental protocol, sixteen tasks handling powered tools were executed by two workers. Hand-arm vibration was assessed subjectively by 16 observers according to the proposed subjective assessment method. As a gold standard reference, hand-arm vibration was measured objectively using a vibration measurement device. Weighted κ's were calculated to assess validity, intra-class-correlation coefficients (ICCs) were calculated to assess inter-observer reliability. Inter-observer reliability of the subjective assessments depicting the agreement among observers can be expressed by an ICC of 0.708 (0.511-0.873). The validity of the subjective assessments as compared to the gold-standard reference can be expressed by a weighted κ of 0.535 (0.285-0.785). Besides, the percentage of exact agreement of the subjective assessment compared to the objective measurement was relatively low (i.e., 52% of all tasks). This study shows that subjectively assessed hand-arm vibrations are fairly reliable among observers and moderately valid. This assessment method is a first attempt to use subjective risk assessments of hand-arm vibration. Although, this assessment method can benefit from some future improvement, it can be of use in future studies and in field-based ergonomic assessments. PMID:24721008

  1. Application of vibration to wrist and hand skin affects fingertip tactile sensation.

    PubMed

    Lakshminarayanan, Kishor; Lauer, Abigail W; Ramakrishnan, Viswanathan; Webster, John G; Seo, Na Jin

    2015-07-14

    A recent study showed that fingertip pads' tactile sensation can improve by applying imperceptible white-noise vibration to the skin at the wrist or dorsum of the hand in stroke patients. This study further examined this behavior by investigating the effect of both imperceptible and perceptible white-noise vibration applied to different locations within the distal upper extremity on the fingertip pads' tactile sensation in healthy adults. In 12 healthy adults, white-noise vibration was applied to one of four locations (dorsum hand by the second knuckle, thenar and hypothenar areas, and volar wrist) at one of four intensities (zero, 60%, 80%, and 120% of the sensory threshold for each vibration location), while the fingertip sensation, the smallest vibratory signal that could be perceived on the thumb and index fingertip pads, was assessed. Vibration intensities significantly affected the fingertip sensation (P < 0.01) in a similar manner for all four vibration locations. Specifically, vibration at 60% of the sensory threshold improved the thumb and index fingertip tactile sensation (P < 0.01), while vibration at 120% of the sensory threshold degraded the thumb and index fingertip tactile sensation (P < 0.01) and the 80% vibration did not significantly change the fingertip sensation (P > 0.01), all compared with the zero vibration condition. This effect with vibration intensity conforms to the stochastic resonance behavior. Nonspecificity to the vibration location suggests the white-noise vibration affects higher level neuronal processing for fingertip sensing. Further studies are needed to elucidate the neural pathways for distal upper extremity vibration to impact fingertip pad tactile sensation. PMID:26177959

  2. Application of vibration to wrist and hand skin affects fingertip tactile sensation

    PubMed Central

    Lakshminarayanan, Kishor; Lauer, Abigail W; Ramakrishnan, Viswanathan; Webster, John G; Seo, Na Jin

    2015-01-01

    A recent study showed that fingertip pads’ tactile sensation can improve by applying imperceptible white-noise vibration to the skin at the wrist or dorsum of the hand in stroke patients. This study further examined this behavior by investigating the effect of both imperceptible and perceptible white-noise vibration applied to different locations within the distal upper extremity on the fingertip pads’ tactile sensation in healthy adults. In 12 healthy adults, white-noise vibration was applied to one of four locations (dorsum hand by the second knuckle, thenar and hypothenar areas, and volar wrist) at one of four intensities (zero, 60%, 80%, and 120% of the sensory threshold for each vibration location), while the fingertip sensation, the smallest vibratory signal that could be perceived on the thumb and index fingertip pads, was assessed. Vibration intensities significantly affected the fingertip sensation (P < 0.01) in a similar manner for all four vibration locations. Specifically, vibration at 60% of the sensory threshold improved the thumb and index fingertip tactile sensation (P < 0.01), while vibration at 120% of the sensory threshold degraded the thumb and index fingertip tactile sensation (P < 0.01) and the 80% vibration did not significantly change the fingertip sensation (P > 0.01), all compared with the zero vibration condition. This effect with vibration intensity conforms to the stochastic resonance behavior. Nonspecificity to the vibration location suggests the white-noise vibration affects higher level neuronal processing for fingertip sensing. Further studies are needed to elucidate the neural pathways for distal upper extremity vibration to impact fingertip pad tactile sensation. PMID:26177959

  3. Reduction of the vibration of the hand-arm system by optimization of rotary hammer drills.

    PubMed

    Weinert, K; Gillmeister, F

    1996-02-01

    When operating a hand-held vibrating power tool, for example impact drills and rotary hammers, high vibration loads are introduced into the hand-arm system of the operator. In the long run these mechanical vibrations can lead to health problems of the hand-arm system. Hammer drilling tools for treatment of mineral materials are offered with many different designs of the cutting edge in the diameter range between 16 mm and 50 mm. In this research project the influences of the cutting edge design of drilling tools on the vibration characteristics of rotary hammers are investigated. The vibration exposure of the hand-arm system due to the tool and the volume of chip production are regarded. The gauge being a combination of the weighted acceleration and the drilling capacity. Based on the current spectrum of drillings tools neutral test have been developed to examine geometrical parameters. Both sets of drilling tools have been subjected to the same test programme. The analysis of the results led to the definition of the characteristics of an optimized rotary hammer drilling tool. Lists of criterions have been developed for the different groups of tools. Using these it is possible to create drilling tools optimized for vibration exposure. This was demonstrated by prototype drilling tools. The comparison of the results showed, that the averaged volume of chip production could be significantly improved by modifying the design of the drilling tools retaining the weighted acceleration. The comparison also showed that the total vibration severity parameter decreased. PMID:8996667

  4. How likely is it that Stockholm stage 1 of the hand arm vibration syndrome will progress to stages 2 and 3?

    PubMed

    Lawson, I J; McGeoch, K L

    1999-08-01

    The progression of symptoms in the hand arm vibration syndrome (HAVS) is dependent on the interaction of individual and workplace factors. Workplace factors include type, magnitude and intermittency of exposure to hand transmitted vibration (HTV), anti-vibration tool design and workpiece characteristics. Individual susceptibility and constitutional factors are poorly understood and the reliance on anamnesis for diagnosis can lead to recall bias, inaccurate classification and an unreliable assessment of the stage of deterioration. This may be overcome by the adoption of multiple standardized testing. The introduction of a policy covering identification, risk assessment, health surveillance and reasonably practicable control measures will have the most significant impact on the incidence of new cases and deterioration in established cases. PMID:10628049

  5. Vibrations of ordered counterions around left- and right-handed DNA double helixes

    NASA Astrophysics Data System (ADS)

    Perepelytsya, S. M.; Volkov, S. N.

    2013-06-01

    The vibrations of ordered counterions around right- and left-handed DNA double helix are studied. To determine the modes of DNA conformational vibrations the structure of the double helix with counterions is considered as ionic lattice (ion-phosphate lattice). Using the developed approach the frequencies and Raman intensities for right-handed B-form and left-handed Z-form of the double helix with Na+, K+, Rb+, Cs+, and Mg2+ counterions are calculated. The obtained frequencies of vibrations of internal structure elements of the double helix (<100 cm-1) weakly depend on counterion type. In contrast, the vibrations of the ion-phosphate lattice are determined by counterion mass and charge. The frequencies of ion-phosphate vibrations of alkali metal counterions decrease from 180 to 100 cm-1, while their Raman intensities increase as the counterion mass increases for the both B- and Z-DNA. In the case of Z-DNA new mode of ion-phosphate vibrations near 150 cm-1 is found. This mode is characterized by vibrations of Mg2+ counterions with respect to the phosphates of different strands of the double helix. Our results explain the experimental Raman spectra of Z-DNA.

  6. Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces.

    PubMed

    Dong, Ren G; Sinsel, Erik W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; McDowell, Thomas W; Wu, John Z

    2015-09-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  7. Research on simultaneous impact of hand-arm and whole-body vibration.

    PubMed

    Kowalski, Piotr; Zając, Jacek

    2012-01-01

    This article presents the results of laboratory tests on the combined effect of whole-body vibration (WBV) and hand-arm vibration (HAV). The reactions of subjects exposed to various combinations of vibration were recorded. The vibrotactile perception threshold (VPT) test identified changes caused by exposure to vibration. Ten male subjects met the criteria of the study. There were 4 series of tests: a reference test and tests after exposure to HAV, WBV, and after simultaneous exposure to HAV and WBV. An analysis of the results (6000 ascending and descending VPTs) showed that the changes in VPTs were greatest after simultaneous exposure to both kinds of vibration. The increase in VPT, for all stimulus frequencies, was then higher than after exposure to HAV or WBV only. PMID:22429529

  8. Transcriptional Pathways Altered in Response to Vibration in a Model of Hand-Arm Vibration Syndrome

    PubMed Central

    Waugh, Stacey; Kashon, Michael L.; Li, Shengqiao; Miller, Gerome R.; Johnson, Claud; Krajnak, Kristine

    2016-01-01

    Objective The aim of this study was to use an established model of vibration-induced injury to assess frequency-dependent changes in transcript expression in skin, artery, and nerve tissues. Methods Transcript expression in tissues from control and vibration-exposed rats (4 h/day for 10 days at 62.5, 125, or 250 Hz; 49 m/s2, rms) was measured. Transcripts affected by vibration were used in bioinformatics analyses to identify molecular- and disease-related pathways associated with exposure to vibration. Results Analyses revealed that cancer-related pathways showed frequency-dependent changes in activation or inhibition. Most notably, the breast-related cancer-1 pathway was affected. Other pathways associated with breast cancer type 1 susceptibility protein related signaling, or associated with cancer and cell cycle/cell survivability were also affected. Conclusion Occupational exposure to vibration may result in DNA damage and alterations in cell signaling pathways that have significant effects on cellular division. PMID:27058473

  9. Robot-assisted assessment of vibration perception and localization on the hand.

    PubMed

    Lambercy, Olivier; Kim, Yeongmi; Gassert, Roger

    2013-03-01

    Sensory perception is crucial for motor learning and the control of fine manipulations. However, therapy after stroke still strongly focuses on the training of motor skills. Sensory assessments are often left out or provide only very subjective data from poorly controlled stimuli. This paper presents a vibration detection/localization test with the Robotic Sensory Trainer, a device that focuses entirely on the assessment and training of sensory function of the hand, with the aim of gaining insights into the prevalence and severity of sensory deficits after stroke, and to provide semiobjective data on absolute and difference perception thresholds in patients. An initial feasibility study investigated localization performance and reaction time during the discrimination of vibration stimuli presented in four locations on the dominant and nondominant hands of 13 healthy volunteers. High correct detection rates were observed (mean ± SD of 99.6% ± 0.6%), touch screen PC Robotic Sensory Trainer which were found to be significantly different between stimulus locations on the dominant hand. Average correct detection rates were not statistically different between dominant and nondominant hand. These data will serve as baseline for future measurements on elderly and stroke subjects, and suggest that data from the nonimpaired hand could be used to identify and assess sensory deficits in the affected hand of stroke patients. PMID:23194307

  10. Vibrations transmitted to human subjects through passenger seats and considerations of passenger comfort

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.

    1975-01-01

    An experimental study was conducted to determine the vertical and lateral vibration-transmission characteristics of several types of transport vehicle seats (two aircraft and one bus) to obtain preliminary estimates and comparisons of the ride acceptability of the various seat types. Results of this investigation indicate that from the standpoint of human comfort the seats exhibit undesirable dynamic response characteristics. Amplification of floor vibrations occurred at the frequencies known to be most critical for human comfort in both vertical and lateral axes. An average transmissibility function for aircraft seats was tabulated together with the associated variability for use by designers who incorporate similar types of seats in their vehicles. The acceptability of vibrations resulting from floor inputs of 0.10g and 0.15g was low over a broad range of frequencies for both axes and all seat types, and was especially low at frequencies where the input was being amplified.

  11. Development of linear and nonlinear hand-arm vibration models using optimization and linearization techniques.

    PubMed

    Rakheja, S; Gurram, R; Gouw, G J

    1993-10-01

    Hand-arm vibration (HAV) models serve as an effective tool to assess the vibration characteristics of the hand-tool system and to evaluate the attenuation performance of vibration isolation mechanisms. This paper describes a methodology to identify the parameters of HAV models, whether linear or nonlinear, using mechanical impedance data and a nonlinear programming based optimization technique. Three- and four-degrees-of-freedom (DOF) linear, piecewise linear and nonlinear HAV models are formulated and analyzed to yield impedance characteristics in the 5-1000 Hz frequency range. A local equivalent linearization algorithm, based upon the principle of energy similarity, is implemented to simulate the nonlinear HAV models. Optimization methods are employed to identify the model parameters, such that the magnitude and phase errors between the computed and measured impedance characteristics are minimum in the entire frequency range. The effectiveness of the proposed method is demonstrated through derivations of models that correlate with the measured X-axis impedance characteristics of the hand-arm system, proposed by ISO. The results of the study show that a linear model cannot predict the impedance characteristics in the entire frequency range, while a piecewise linear model yields an accurate estimation. PMID:8253830

  12. Combined effects of noise and hand-arm vibration on auditory organ and peripheral circulation

    NASA Astrophysics Data System (ADS)

    Miyakita, T.; Miura, H.; Futatsuka, M.

    1991-12-01

    This paper first presents an overview of an epidemiological study on noise-induced hearing loss (NIHL) in relation to vibration-induced white finger (VWF). Secondly, the results obtained in a model experiment with a chain-saw under laboratory conditions are discussed from the viewpoints of elucidating the etiological mechanisms of VWF and NIHL. In the epidemiological study, in which 499 chain-saw workers were examined, chain-saw workers with VWF showed a significantly greater hearing loss at high frequencies than those without VWF. Next, an experimental study was designed to determine whether a combination of noise and vibration produced more pronounced changes in temporary shifts of finger skin temperature and temporary threshold shift (TTS) of hearing than those resulting from exposure to either stress alone. The results suggested that noise might play a part in inducing the constriction of the peripheral vessels seen with local exposure to vibration, and that hand-arm vibration may produce an additive effect on the noise-induced TTS. Furthermore, finger skin temperature and finger blood flow were measured simultaneously as indicators of peripheral circulatory movement for five healthy subjects. The relation between the synergistic action of noise and vibration and the participation of the sympathetic nervous system are also discussed.

  13. Effect of Wheelchair Frame Material on Users' Mechanical Work and Transmitted Vibration

    PubMed Central

    Aissaoui, Rachid

    2014-01-01

    Wheelchair propulsion exposes the user to a high risk of shoulder injury and to whole-body vibration that exceeds recommendations of ISO 2631-1:1997. Reducing the mechanical work required to travel a given distance (WN-WPM, weight-normalized work-per-meter) can help reduce the risk of shoulder injury, while reducing the vibration transmissibility (VT) of the wheelchair frame can reduce whole-body vibration. New materials such as titanium and carbon are used in today's wheelchairs and are advertised to improve both parameters, but current knowledge on this matter is limited. In this study, WN-WPM and VT were measured simultaneously and compared between six folding wheelchairs (1 titanium, 1 carbon, and 4 aluminium). Ten able-bodied users propelled the six wheelchairs on three ground surfaces. Although no significant difference of WN-WPM was found between wheelchairs (P < 0.1), significant differences of VT were found (P < 0.05). The carbon wheelchair had the lowest VT. Contrarily to current belief, the titanium wheelchair VT was similar to aluminium wheelchairs. A negative correlation between VT and WN-WPM was found, which means that reducing VT may be at the expense of increasing WN-WPM. Based on our results, use of carbon in wheelchair construction seems promising to reduce VT without increasing WN-WPM. PMID:25276802

  14. Raynaud's phenomenon in different groups of workers using hand-held vibrating tools.

    PubMed

    Harazin, B; Langauer-Lewowicka, H

    1996-05-01

    The dose-effect relationship showed in the Annex A of the ISO standard 5349-1986 can be used for preventing vibration-induced white fingers (VWF) because it allows to calculate the latent period for the lowest risk of VWF. The aim of this study was to assess the risk of VWF in three different occupational groups of workers whose members operated the same vibrating power tools and the same industrial processes throughout the workday. Each occupational group was employed in two foundries and they were considered to be very stable with a low turnover rate. The mean frequency-weighted acceleration magnitudes measured from pneumatic rammers (25.3 +/- 3.3 ms-2) where three times higher than from chipping hammers (8.4 +/- 3.8 ms-2) and six times higher than from grinders (3.8 +/- 1.1 ms-2). Medical examinations were carried out in 102 men consisting of 22 chippers, 42 rammers and 38 grinders. The results of this study showed that the relationship between lifetime exposure to hand-arm vibration and the vascular disorders can be predicted quite well using the Annex A of ISO standard only in one occupational group, that is, in chippers. Thirty-six percent of chippers reported blanching symptoms, but only five percent of the rammers and three percent of the grinders had these vascular disturbances. Our results may be explained by the fact that vibration received by an operator depends on the manner in which the tool is used. In a foundry three following work processes are performed: preparing forms in ramming mix, cleaning and grinding of castings during which different forces are used by operators. It seems very likely that the energy absorbtion in the hands and arms of chippers must be stronger than in other studied groups. PMID:8996728

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

    PubMed Central

    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

  16. Illusory movements induced by tendon vibration in right- and left-handed people.

    PubMed

    Tidoni, Emmanuele; Fusco, Gabriele; Leonardis, Daniele; Frisoli, Antonio; Bergamasco, Massimo; Aglioti, Salvatore Maria

    2015-02-01

    Frequency-specific vibratory stimulation of peripheral tendons induces an illusion of limb movement that may be useful for restoring proprioceptive information in people with sensorimotor disability. This potential application may be limited by inter- and intra-subject variability in the susceptibility to such an illusion, which may depend on a variety of factors. To explore the influence of stimulation parameters and participants' handedness on the movement illusion, we vibrated the right and left tendon of the biceps brachii in a group of right- and left-handed people with five stimulation frequencies (from 40 to 120 Hz in step of 20 Hz). We found that all participants reported the expected illusion of elbow extension, especially after 40 and 60 Hz. Left-handers exhibited less variability in reporting the illusion compared to right-handers across the different stimulation frequencies. Moreover, the stimulation of the non-dominant arm elicited a more vivid illusion with faster onset relative to the stimulation of the dominant arm, an effect that was independent from participants' handedness. Overall, our data show that stimulation frequency, handedness and arm dominance influence the tendon vibration movement illusion. The results are discussed in reference to their relevance in linking motor awareness, improving current devices for motor ability recovery after brain or spinal damage and developing prosthetics and virtual embodiment systems. PMID:25294499

  17. Anti-vibration gloves?

    PubMed

    Hewitt, Sue; Dong, Ren G; Welcome, Daniel E; McDowell, Thomas W

    2015-03-01

    For exposure to hand-transmitted vibration (HTV), personal protective equipment is sold in the form of anti-vibration (AV) gloves, but it remains unclear how much these gloves actually reduce vibration exposure or prevent the development of hand-arm vibration syndrome in the workplace. This commentary describes some of the issues that surround the classification of AV gloves, the assessment of their effectiveness and their applicability in the workplace. The available information shows that AV gloves are unreliable as devices for controlling HTV exposures. Other means of vibration control, such as using alternative production techniques, low-vibration machinery, routine preventative maintenance regimes, and controlling exposure durations are far more likely to deliver effective vibration reductions and should be implemented. Furthermore, AV gloves may introduce some adverse effects such as increasing grip force and reducing manual dexterity. Therefore, one should balance the benefits of AV gloves and their potential adverse effects if their use is considered. PMID:25381184

  18. Occupational musculoskeletal disorders in the neck and upper limbs of forestry workers exposed to hand-arm vibration.

    PubMed

    Bovenzi, M; Zadini, A; Franzinelli, A; Borgogni, F

    1991-05-01

    An epidemiologic and clinical study of neck and upper limb musculoskeletal disorders was carried out on 65 vibration-exposed forestry operators using chain-saws and 31 comparable control subjects (maintenance workers) performing manual activity and not exposed to vibration. Upper limb function was evaluated by measuring finger and wrist circumference size, maximal hand grip strength and range of motion manoeuvres in both the controls and the exposed workers. Vibration from two chain-saws was measured, and vibration exposure for each forestry worker was assessed in terms of 4 h energy-equivalent frequency-weighted acceleration according to ISO 5349. Job analysis indicated a slight excess risk of upper extremity cumulative trauma disorders (CTDs) in the forestry operators compared with the control workers. After adjustment for age and body constitution, significantly higher prevalence rates of persistent upper limb pain, muscle-tendon syndromes and carpal tunnel syndrome were observed among the forestry workers than among the controls. In the forestry operators, the occurrence of upper limb musculoskeletal disorders increased with increasing vibration exposure. Upper limb function was found to be impaired in the forestry workers compared with the controls. Vibration exposure was significantly related to increased finger circumference size, diminished muscle force and reduced joint function. Even though it is difficult to establish the relative importance of vibration and ergonomic factors in the aetiology of CTDs, nevertheless the results of this study indicate that musculoskeletal impairment to the upper limbs was more severe in the forestry operators than in the controls who did solely manual work. This finding and the observed dose-effect relationships suggest that vibration stress is an important contributor to the development of musculoskeletal disorders in workers using hand-held vibrating tools. PMID:1653132

  19. A non-resonant, frequency up-converted electromagnetic energy harvester from human-body-induced vibration for hand-held smart system applications

    NASA Astrophysics Data System (ADS)

    Halim, Miah A.; Park, Jae Y.

    2014-03-01

    We present a non-resonant, frequency up-converted electromagnetic energy harvester that generates significant power from human-body-induced vibration, e.g., hand-shaking. Upon excitation, a freely movable non-magnetic ball within a cylinder periodically hits two magnets suspended on two helical compression springs located at either ends of the cylinder, allowing those to vibrate with higher frequencies. The device parameters have been designed based on the characteristics of human hand-shaking vibration. A prototype has been developed and tested both by vibration exciter (for non-resonance test) and by manual hand-shaking. The fabricated device generated 110 μW average power with 15.4 μW cm-3 average power density, while the energy harvester was mounted on a smart phone and was hand-shaken, indicating its ability in powering portable hand-held smart devices from low frequency (<5 Hz) vibrations.

  20. Design of a suspended handle to attenuate rock drill hand-arm vibration: model development and validation

    NASA Astrophysics Data System (ADS)

    Oddo, R.; Loyau, T.; Boileau, P. E.; Champoux, Y.

    2004-08-01

    Pneumatic jackleg drills are widespread percussion tools used in the mining industry. Hand-arm vibration frequency-weighted exposure levels evaluated within the 6.3-1250 Hz frequency range have been found to be on the order of 25 m/s 2 when operating this tool in typical mining conditions. This study concerns the development of a suspended handle designed to provide attenuation of the vibration and shocks being generated at the tool blow frequency, which occurs between 35 and 45 Hz on most types of pneumatic drills. The results of the first phase of development of such a handle are presented in this paper. They are based on the development and validation of a model combining the suspended handle and the hand-arm system. For that purpose, the hand-arm system is represented by a four-degree-of-freedom lumped parameter model, referred to as model 2 in the ISO 10068 standard. As part of this investigation, a model is developed to represent two different types of suspended handles: one incorporating helicoidal springs, the other viscoelastic mounts. These combined hand-arm-suspended handle models are then validated by comparing the model predictions with the measurements of vibration transmissibility realized while exciting the suspended handles on an electrodynamic shaker system. These measurements involved the use of human subjects holding the handles while applying a push force varying from 0 to 80 N, and a grip force ranging from 20 to 50 N. For values of grip and push forces set at 50 N, good agreement was achieved between the model predictions and the measurements, especially at frequencies above 35 Hz. The hand was found to have a significant influence on the vibration transmissibility responses of both suspended handles. When the values of suspension stiffness were selected to provide a resonant frequency of 25 Hz for the free handles, the vibration attenuation achieved at a frequency of 35 Hz was on the order of 30% when gripping the handle, while a slight

  1. Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

    PubMed Central

    Dong, Ren G.; Sinsel, Erik W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  2. Research into hand-arm vibration syndrome and its prevention in Japan.

    PubMed

    Yamada, S; Sakakibara, H

    1994-05-01

    Research on vibration syndrome in Japan began in the 1930s with studies of the disorder among railway, mining and shipyard workers. In 1947, the Ministry of Labor decided vibration syndrome among operators of rock drills and riveters etc. was an occupational disease. Industrial developments in the 1950s and 1960s promoted the survey of vibration syndrome in mining, stone quarrying and forestry. The Ministry of Labor (1965) and the National Personnel Agency (1966) legally recognized vibration syndrome among chain saw operators as an occupational disease. Guidelines for prevention and early therapy were issued in the 1970s and 80s. From the late 1970s into the 1980s, research focused on the clinical picture, diagnostic methods and therapy. In pathophysiology, advances were made in research into the autonomic nervous system during the 1980s. The 1970s and 80s saw a steady reduction in risk from technological change and working conditions, and advances in medical care, education and meteorological forecasting. A comprehensive prevention system established in the 1980s in the Japanese forest industry involved: 1) work restrictions, 2) an improved health care system, 3) advances in the design of vibrating tools, handle-warming devices, and 4) improved worker education. This comprehensive preventive system was legally introduced into other industries, resulting in a rapid decrease in the incidence of vibration syndrome in Japan. PMID:7708109

  3. Hand-arm vibration in the aetiology of hearing loss in lumberjacks.

    PubMed Central

    Pyykkö, I; Starck, J; Färkkilä, M; Hoikkala, M; Korhonen, O; Nurminen, M

    1981-01-01

    A longitudinal study of hearing loss was conducted among a group of lumberjacks in the years 1972 and 1974--8. The number of subjects increased from 72 in 1972 to 203 in 1978. They were classified according to (1) a history of vibration-induced white finger (VWF), (2) age, (3) duration of exposure, an (4) duration of ear muff usage. The hearing level at 4000 Hz was used to indicate the noise-induced permanent threshold shift (NIPTS). The lumberjacks were exposed, at their present pace of work, to noise, Leq values 96-103 dB(A), and to the vibration of a chain saw (linear acceleration 30-70 ms-2). The chain saws of the early 1960s were more hazardous, with the average noise level of 111 dB(A) and a variation acceleration of 60-180 ms-2. When classified on the basis of age, the lumberjacks with VWF had about a 10 dB greater NIPTS than subjects without VWF. NIPTS increased with the duration of exposure to chain saw noise, but with equal noise exposure the NIPTS was about 10 dB greater in lumberjacks with VWF than without VWF. With the same duration of ear protection the lumberjacks with VWF consistently had about a 10 dB greater NIPTS than those without VWF. The differences in NIPTS were statistically significant. The possible reason for more advanced NIPTS in subjects with VWF is that vibration might operate in both of these disorders through a common mechanism--that is, producing a vasoconstriction in both cochlear and digital blood vessels as a result of sympathetic nervous system activity. PMID:7272242

  4. Objective testing for vasospasm in the hand-arm vibration syndrome.

    PubMed Central

    Allen, J A; Doherty, C C; McGrann, S

    1992-01-01

    Since vibration white finger (VWF) became a prescribed industrial disease in 1985, objective testing for the diagnosis and grading of the severity of the condition has become desirable. Measurements have been made of finger blood flow and finger systolic pressure before and after cold challenge in 22 healthy control subjects and 34 men presenting for medical examination in connection with compensation claims for VWF. This type of testing has previously produced one false negative result in 35 patients with an established clinical diagnosis of Raynaud's syndrome and no false positives in 40 control subjects. Finger blood flow was not significantly different in the claimants and controls in either warm or cool environments at local finger temperatures from 32 degrees C down to 20 degrees C. Finger systolic pressure in the claimants was not significantly different from that in the controls when the fingers were warm at 32 degrees C. After five minutes middle phalangeal cooling to 15 or 10 degrees C, finger systolic pressure was 0 mm Hg in 22 of the claimants indicating that vasospasm had occurred. No vasospasm occurred in the remaining 12 claimants or in any of the 22 control subjects. By clinical assessment alone, 26 of the 34 claimants had been thought to have VWF and 21 (81%) of these exhibited vasospasm in the laboratory. Of the eight considered not to have VWF, only one exhibited vasospasm in the laboratory. PMID:1419856

  5. A systematic review of diagnostic performance of quantitative tests to assess musculoskeletal disorders in hand-arm vibration syndrome

    PubMed Central

    MAHBUB, MH; KUROZAWA, Youichi; ISHITAKE, Tatsuya; KUME, Yukinori; MIYASHITA, Kazuhisa; SAKAKIBARA, Hisataka; SATO, Shuji; TOIBANA, Norikuni; HARADA, Noriaki

    2015-01-01

    The purpose was to systematically review the published reports for the clinical utility of quantitative objective tests commonly used for diagnosing musculoskeletal disorders in hand-arm vibration syndrome (HAVS). Two reviewers independently conducted a computerized literature search in PubMed and Scopus using predefined criteria, and relevant papers were identified. The articles were screened in several stages and considered for final inclusion. Quality of the selected papers was evaluated by a modified QUADAS tool. Relevant data were extracted as necessary. For this review, only 4 relevant studies could be identified for detailed examination. Grip strength, pinch strength, and Purdue pegboard tests were commonly used with their reported sensitivity and specificity ranging between 1.7 to 65.7% and 65.2 to 100%, 1.7 to 40% and 94 to 100%, and 44.8 to 85% and 78 to 95%, respectively. A considerable difference across the studies was observed with respect to patient and control populations, diagnostic performance and cut-off values of different tests. Overall, currently available English-language limited literature do not provide enough evidence in favour of the application of grip strength and pinch strength tests for diagnosing musculoskeletal injuries in HAVS; Purdue pegboard test seems to have some diagnostic value in evaluating impaired dexterity in HAVS. PMID:26051288

  6. The Efficacy of Anti-vibration Gloves

    PubMed Central

    Hewitt, Sue; Dong, Ren; McDowell, Tom; Welcome, Daniel

    2016-01-01

    Anyone seeking to control the risks from vibration transmitted to the hands and arms may contemplate the use of anti-vibration gloves. To make an informed decision about any type of personal protective equipment, it is necessary to have performance data that allow the degree of protection to be estimated. The information provided with an anti-vibration glove may not be easy to understand without some background knowledge of how gloves are tested and does not provide any clear route for estimating likely protection. Some of the factors that influence the potential efficacy of an anti-vibration glove include how risks from hand–arm vibration exposure are assessed, how the standard test for a glove is carried out, the frequency range and direction of the vibration for which protection is sought, how much hand contact force or pressure is applied and the physical limitations due to glove material and construction. This paper reviews some of the background issues that are useful for potential purchasers of anti-vibration gloves. Ultimately, anti-vibration gloves cannot be relied on to provide sufficient and consistent protection to the wearer and before their use is contemplated all other available means of vibration control ought first to be implemented.

  7. Structural, electronic and vibrational properties of few-layer 2H-and 1T-TaSe2

    DOE PAGESBeta

    Yan, Jia -An; Dela Cruz, Mack A.; Cook, Brandon G.; Varga, Kalman

    2015-11-16

    Two-dimensional metallic transition metal dichalcogenides (TMDs) are of interest for studying phenomena such as charge-density wave (CDW) and superconductivity. Few-layer tantalum diselenides (TaSe2) are typical metallic TMDs exhibiting rich CDW phase transitions. However, a description of the structural, electronic and vibrational properties for different crystal phases and stacking configurations, essential for interpretation of experiments, is lacking. We present first principles calculations of structural phase energetics, band dispersion near the Fermi level, phonon properties and vibrational modes at the Brillouin zone center for different layer numbers, crystal phases and stacking geometries. Evolution of the Fermi surfaces as well as the phononmore » dispersions as a function of layer number reveals dramatic dimensionality effects in this CDW material. Lastly, our results indicate strong electronic interlayer coupling, detail energetically possible stacking geometries, and provide a basis for interpretation of Raman spectra.« less

  8. Spatial resonance in a small artery excited by vibration input as a possible mechanism to cause hand-arm vascular disorders

    NASA Astrophysics Data System (ADS)

    Pattnaik, Shrikant; Banerjee, Rupak; Kim, Jay

    2012-04-01

    Hand-arm vibration syndrome (HAVS) is collectively a vasospastic and neurodegenerative occupational disease. One of the major symptoms of HAVS is vibration white finger (VWF) caused by exaggerated vasoconstriction of the arteries and skin arterioles. While VWF is a very painful and costly occupational illness, its pathology has not been well understood. In this study a small artery is modeled as a fluid filled elastic tube whose diameter changes along the axial direction. Equations of motion are developed by considering interactions between the fluid, artery wall and soft-tissue bed. It is shown that the resulting wave equation is the same as that of the basilar membrane in the cochlea of mammals. Therefore, the artery system shows a spatial resonance as in the basilar membrane, which responds with the highest amplitude at the location determined by the vibration frequency. This implies that a long-term use of one type of tool will induce high-level stresses at a few identical locations of the artery that correspond to the major frequency components of the tool. Hardening and deterioration of the artery at these locations may be a possible cause of VWF.

  9. Hand-arm vibration, noise, temperature and static load--an experimental study of peripheral circulation while operating chain-saws.

    PubMed

    Miyakita, T; Miura, H; Futatsuka, M

    1990-01-01

    From the viewpoint of elucidating the etiological mechanism of vibration-induced white finger (VWF), a model experiment was designed using a chain-saw under laboratory conditions. Finger skin temperature and finger blood flow were measured simultaneously as indicators of peripheral circulatory movement, using a thermister and an apparatus for measuring tissue blood flow based on the thermal diffusion method. In the first project (Experiment A), five healthy subjects operated a chain-saw at a high working speed with-out actually cutting anything. In the second project (Experiment B), seven healthy subjects were exposed to three different kinds of experiments with combinations of hand-arm vibration, noise and tool weight at about 15 degrees C room temperature. In the third project (Experiment C), the effects of tool weight and grip force were examined. In the fourth project (Experiment D), patients suffering from vibration disease were exposed to hand-arm vibration and the noise of a chain-saw for 2 minutes. In experiment A, the mean value of the normalized finger skin temperature decreased gradually with cyclic changes corresponding to each exposure and break period. Changes in finger blood flow had almost the same pattern as the changes of skin temperature, but the recovery of blood flow during a 30 sec break period was notable and a slight elevation of the base line was observed. In experiment B, the mean value for the normalized finger skin temperature decreased much more when the subjects operated a chain-saw at a high working speed than when they operated the chain-saw with the noise isolated by double hearing protection. On the other hand, the results obtained in experiment C indicated that the effect of tool weight should be considered as an important factor for investigating the acute changes in peripheral circulation. In experiment D, some patients showed an unusual pattern in the change of blood flow during a post exposure period which was not seen in

  10. Reproducing Deep Tunneling Splittings, Resonances, and Quantum Frequencies in Vibrational Spectra From a Handful of Direct Ab Initio Semiclassical Trajectories.

    PubMed

    Conte, Riccardo; Aspuru-Guzik, Alán; Ceotto, Michele

    2013-10-17

    A time-dependent semiclassical approach for vibrational spectra calculations is shown to describe deep tunneling splittings, resonances, and quantum frequencies in multidimensional multiwell systems, by propagating a very limited number of classical trajectories. The approach is tested on ammonia by evolving eight trajectories on a full-dimensional PES. Quantum effects are reproduced, and results are in good agreement with time-independent quantum calculations. All the features are maintained when ab initio "on-the-fly" dynamics is adopted, thus demonstrating that precomputation of the PES can be avoided. The approach overcomes the typical scaling issues of quantum mechanical techniques without introducing any simplifications nor reductions of dimensionality of the problem. The proposed methodology is promising for further applications to systems of major complexity. PMID:26705583

  11. A systematic review of the etiopathogenesis of Kienböck's disease and a critical appraisal of its recognition as an occupational disease related to hand-arm vibration

    PubMed Central

    2012-01-01

    Background We systematically reviewed etiological factors of Kienböck’s disease (osteonecrosis of the lunate) discussed in the literature in order to examine the justification for including Kienböck’s disease (KD) in the European Listing of Occupational Diseases. Methods We searched the Ovid/Medline and the Cochrane Library for articles discussing the etiology of osteonecrosis of the lunate published since the first description of KD in 1910 and up until July 2012 in English, French or German. Literature was classified by the level of evidence presented, the etiopathological hypothesis discussed, and the author's conclusion about the role of the etiopathological hypothesis. The causal relationship between KD and hand-arm vibration was elucidated by the Bradford Hill criteria. Results A total of 220 references was found. Of the included 152 articles, 140 (92%) reached the evidence level IV (case series). The four most frequently discussed factors were negative ulnar variance (n=72; 47%), primary arterial ischemia of the lunate (n=63; 41%), trauma (n=63; 41%) and hand-arm vibration (n=53; 35%). The quality of the cohort studies on hand-arm vibration did not permit a meta-analysis to evaluate the strength of an association to KD. Evidence for the lack of consistency, plausibility and coherence of the 4 most frequently discussed etiopathologies was found. No evidence was found to support any of the nine Bradford Hill criteria for a causal relationship between KD and hand-arm vibration. Conclusions A systematic review of 220 articles on the etiopathology of KD and the application of the Bradford Hill criteria does not provide sufficient scientific evidence to confirm or refute a causal relationship between KD and hand-arm vibration. This currently suggests that, KD does not comply with the criteria of the International Labour Organization determining occupational diseases. However, research with a higher level of evidence is required to further determine if hand

  12. Suspected vibration magnitude on the body of chain saw users among National Forest workers in Kyusyu, from 1956 to 1984.

    PubMed

    Sakurai, T

    1990-01-01

    Chain saws were first used in Kyusyu in 1956 for cutting down trees and sawing timber in the national forests. In 1961, some workers complained of symptoms due to the vibrations, but countermeasures were not taken until later. The working system and payment system in those times were different from the systems, today. The magnitudes of the chain saw vibrations were very large and the chain saws were operated for many hours, each day. Workers with VWF (vibration induced white finger) had to continue to operate the chain saws without restriction. Vibration disease is related primarily to the vibration of the tools, but also to the transmission of the vibration to the workers. From the official data on chain saws used in national forests, vibration transmission to the body was determined for workers from 1956 to 1984 by comparing the vibration magnitude on the body during work with modern chain saws and during vibration loading tests with an electrodynamic shaker in the laboratory. The vibrations transmitted to the body in some rule in the observation. If the working posture of chain saw operator was the same as today, the vibration transmission was determined from the tool vibration, tool weight, joint fixation and orientation of the hands and the hands and the arms to the handle (joint elasticity). Older chain saws had 20 to 30 times larger vibration magnitudes than modern chain saws, and were also 2 to 3 times heavier. The vibrations transmitted to the foreheads of earlier workers were approximately the same magnitude as the vibrations at the back of the hands of present workers. Also the daily and annual hours of chain saw use were very long, and there were not sufficient measures to protect from the cold. The vibration in the former days led to more symptoms and lesions than in present times. PMID:2381147

  13. The Effect of a Mechanical Arm System on Portable Grinder Vibration Emissions

    PubMed Central

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

    2016-01-01

    Mechanical arm systems are commonly used to support powered hand tools to alleviate ergonomic stressors related to the development of workplace musculoskeletal disorders. However, the use of these systems can increase exposure times to other potentially harmful agents such as hand-transmitted vibration. To examine how these tool support systems affect tool vibration, the primary objectives of this study were to characterize the vibration emissions of typical portable pneumatic grinders used for surface grinding with and without a mechanical arm support system at a workplace and to estimate the potential risk of the increased vibration exposure time afforded by the use of these mechanical arm systems. This study also developed a laboratory-based simulated grinding task based on the ISO 28927-1 (2009) standard for assessing grinder vibrations; the simulated grinding vibrations were compared with those measured during actual workplace grinder operations. The results of this study demonstrate that use of the mechanical arm may provide a health benefit by reducing the forces required to lift and maneuver the tools and by decreasing hand-transmitted vibration exposure. However, the arm does not substantially change the basic characteristics of grinder vibration spectra. The mechanical arm reduced the average frequency-weighted acceleration by about 24% in the workplace and by about 7% in the laboratory. Because use of the mechanical arm system can increase daily time-on-task by 50% or more, the use of such systems may actually increase daily time-weighted hand-transmitted vibration exposures in some cases. The laboratory acceleration measurements were substantially lower than the workplace measurements, and the laboratory tool rankings based on acceleration were considerably different than those from the workplace. Thus, it is doubtful that ISO 28927-1 is useful for estimating workplace grinder vibration exposures or for predicting workplace grinder acceleration rank

  14. The Effect of a Mechanical Arm System on Portable Grinder Vibration Emissions.

    PubMed

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

    2016-04-01

    Mechanical arm systems are commonly used to support powered hand tools to alleviate ergonomic stressors related to the development of workplace musculoskeletal disorders. However, the use of these systems can increase exposure times to other potentially harmful agents such as hand-transmitted vibration. To examine how these tool support systems affect tool vibration, the primary objectives of this study were to characterize the vibration emissions of typical portable pneumatic grinders used for surface grinding with and without a mechanical arm support system at a workplace and to estimate the potential risk of the increased vibration exposure time afforded by the use of these mechanical arm systems. This study also developed a laboratory-based simulated grinding task based on the ISO 28927-1 (2009) standard for assessing grinder vibrations; the simulated grinding vibrations were compared with those measured during actual workplace grinder operations. The results of this study demonstrate that use of the mechanical arm may provide a health benefit by reducing the forces required to lift and maneuver the tools and by decreasing hand-transmitted vibration exposure. However, the arm does not substantially change the basic characteristics of grinder vibration spectra. The mechanical arm reduced the average frequency-weighted acceleration by about 24% in the workplace and by about 7% in the laboratory. Because use of the mechanical arm system can increase daily time-on-task by 50% or more, the use of such systems may actually increase daily time-weighted hand-transmitted vibration exposures in some cases. The laboratory acceleration measurements were substantially lower than the workplace measurements, and the laboratory tool rankings based on acceleration were considerably different than those from the workplace. Thus, it is doubtful that ISO 28927-1 is useful for estimating workplace grinder vibration exposures or for predicting workplace grinder acceleration rank

  15. Vibration training for upper body: transmission of platform vibrations through cables.

    PubMed

    Tankisheva, Ekaterina; Boonen, Steven; Delecluse, Christophe; Druyts, Hans Lj; Verschueren, Sabine M P

    2014-04-01

    The aim of the present study was to evaluate the vibration transmission from a vibration platform through Vectran cables to the upper body and its relationship to induced muscular activation. Fifteen clinically healthy participants performed 3 different arm exercises-biceps curl, triceps curl, and lateral raise. Vibration transmission to the upper body was assessed over a wide range of accelerations (from 1.90 to 5.98 g) and frequencies (from 25 to 40 Hz). To assess the vibration transmission, 7 triaxial accelerometers were attached from the hand up to the head, and the root-mean-square of acceleration signal of each site-specific body point was calculated. Muscular activity of biceps brachii, triceps brachii, deltoid, and upper trapezius was recorded. The results showed a significant attenuation of the platform accelerations transmitted through the Vectran cables to the upper body. Handle vibration ranged between 27 and 44% of the acceleration delivered by the platform depending on platform vibration parameters (acceleration/frequency). Vibration increased the muscle activity of biceps brachii, triceps brachii, deltoid, and upper trapezius muscles significantly only during biceps curl exercises. No frequency or acceleration effect was found on the size of the muscle response. The results of the present study suggest that a cable-pulley resistance system on a vibration platform channels the vibration safely from the platform to the arms and induces additional muscle activation in some arm muscles when biceps curl exercises are performed. PMID:24077381

  16. Laboratory and workplace assessments of rivet bucking bar vibration emissions.

    PubMed

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

    2015-04-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  17. Laboratory and Workplace Assessments of Rivet Bucking Bar Vibration Emissions

    PubMed Central

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

    2016-01-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  18. Vibrating fuel grapple. [LMFBR

    DOEpatents

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  19. Vibrating fuel grapple

    DOEpatents

    Chertock, deceased, Alan J.; Fox, Jack N.; Weissinger, Robert B.

    1982-01-01

    A reactor refueling method utilizing a vibrating fuel grapple for removing spent fuel assemblies from a reactor core which incorporates a pneumatic vibrator in the grapple head, enabling additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  20. Effect of coating over the handle of a drill machine on vibration transmissibility.

    PubMed

    Singh, Jagvir; Khan, Abid Ali

    2014-03-01

    This study was to see the effect of different coatings on the handle of hand-held drilling machines. Out of five different handles chosen for this study, including one handle uncoated. Root mean square (rms) values of the vibration levels (acceleration) were recorded at the surface of handle and wrist of the operators. Results showed that maximum vibrations were reduced by coating of handle coated with rubber sheet and Rexene (H4) followed by handle coated with cotton sandwiched between jeans cloth (H5). Equivalent vibrations transmitted through coating of handles coated with sponge and velvet (H2) and jute and cotton (H3) were of almost same magnitude and these two coated handles were able to reduce least vibration transmitted. Transmissibility of vibrations along dominant (Z) direction was analyzed using ANOVA. Results showed that coating on handles significantly affected vibration transmitted in Z direction. Vibration transmissibility ratios were found to be 0.354, 0.571, 0.408, 0.4326, and 0.3555 for handles H1, H2, H3, H4 and H5 respectively. PMID:23642474

  1. Vibration Analysis and the Accelerometer

    ERIC Educational Resources Information Center

    Hammer, Paul

    2011-01-01

    Have you ever put your hand on an electric motor or motor-driven electric appliance and felt it vibrate? Ever wonder why it vibrates? What is there about the operation of the motor, or the object to which it is attached, that causes the vibrations? Is there anything "regular" about the vibrations, or are they the result of random causes? In this…

  2. Structural, electronic and vibrational properties of few-layer 2H-and 1T-TaSe2

    SciTech Connect

    Yan, Jia -An; Dela Cruz, Mack A.; Cook, Brandon G.; Varga, Kalman

    2015-11-16

    Two-dimensional metallic transition metal dichalcogenides (TMDs) are of interest for studying phenomena such as charge-density wave (CDW) and superconductivity. Few-layer tantalum diselenides (TaSe2) are typical metallic TMDs exhibiting rich CDW phase transitions. However, a description of the structural, electronic and vibrational properties for different crystal phases and stacking configurations, essential for interpretation of experiments, is lacking. We present first principles calculations of structural phase energetics, band dispersion near the Fermi level, phonon properties and vibrational modes at the Brillouin zone center for different layer numbers, crystal phases and stacking geometries. Evolution of the Fermi surfaces as well as the phonon dispersions as a function of layer number reveals dramatic dimensionality effects in this CDW material. Lastly, our results indicate strong electronic interlayer coupling, detail energetically possible stacking geometries, and provide a basis for interpretation of Raman spectra.

  3. Sexually transmitted diphtheria.

    PubMed

    Berger, Anja; Lensing, Carmen; Konrad, Regina; Huber, Ingrid; Hogardt, Michael; Sing, Andreas

    2013-03-01

    Diphtheria is caused by diphtheria toxin-producing Corynebacterium species. While classical respiratory diphtheria is transmitted by droplets, cutaneous diphtheria often results from minor trauma. This report concerns the first case of sexually transmitted diphtheria in a patient with non-gonococcal urethritis after orogenital contact. PMID:22628666

  4. Hand Safety

    MedlinePlus

    ... en gatillo See More... Hand Anatomy Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening ... en gatillo See More... Hand Anatomy Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening ...

  5. Vibration balanced miniature loudspeaker

    NASA Astrophysics Data System (ADS)

    Schafer, David E.; Jiles, Mekell; Miller, Thomas E.; Thompson, Stephen C.

    2002-11-01

    The vibration that is generated by the receiver (loudspeaker) in a hearing aid can be a cause of feedback oscillation. Oscillation can occur if the microphone senses the receiver vibration at sufficient amplitude and appropriate phase. Feedback oscillation from this and other causes is a major problem for those who manufacture, prescribe, and use hearing aids. The receivers normally used in hearing aids are of the balanced armature-type that has a significant moving mass. The reaction force from this moving mass is the source of the vibration. A modification of the balanced armature transducer has been developed that balances the vibration of its internal parts in a way that significantly reduces the vibration force transmitted outside of the receiver case. This transducer design concept, and some of its early prototype test data will be shown. The data indicate that it should be possible to manufacture transducers that generate less vibration than equivalent present models by 15-30 dB.

  6. Sexually Transmitted Proctitis

    PubMed Central

    Sigle, Gavin W.; Kim, Rebekah

    2015-01-01

    There are many different sexually transmitted infections that can cause proctitis. Recognition of the common symptoms with anoscopic examination is crucial in accurate diagnosis of the pathogen. Clinicians should have a high index of suspicion of more than one inciting pathogen. Treatment should be prompt and extended to sexual partners who have been exposed to the disease. Effective treatment can alleviate the discomfort and potentially serious complications associated with sexually transmitted proctitides. This article illustrates and discusses the clinical presentations, diagnostic pearls, and treatments of sexually transmitted proctitides. PMID:26034402

  7. Sexually Transmitted Diseases

    MedlinePlus

    Sexually transmitted diseases (STDs) are infections that you can get from having sex with someone who has the infection. The causes ... is no cure. Sometimes medicines can keep the disease under control. Correct usage of latex condoms greatly ...

  8. Accelerator vibration issues

    SciTech Connect

    Tennant, R.A.

    1985-01-01

    Vibrations induced in accelerator structures can cause particle-beam jitter and alignment difficulties. Sources of these vibrations may include pump oscillations, cooling-water turbulence, and vibrations transmitted through the floor to the accelerator structure. Drift tubes (DT) in a drift tube linac (DTL) are components likely to affect beam jitter and alignment because they normally have a heavy magnet structure on the end of a long and relatively small support stem. The natural vibrational frequencies of a drift tube have been compared with theoretical predictions. In principle, by knowing natural frequencies of accelerator components and system vibrational frequncies, an accelerator can be designed that does not have these frequencies coinciding. 2 refs., 2 figs., 2 tabs.

  9. Sexually transmitted infections.

    PubMed

    Fuchs, Wolfgang; Brockmeyer, Norbert H

    2014-06-01

    In no other medical field former rare infections of the 1980(th) and 1990(th) occur again as this is seen in the field of venerology which is as well based on the mobility of the population. Increasing rates of infections in Europe, and increasing bacteriological resistances face health professionals with new challenges. The WHO estimates more than 340 million cases of illnesses worldwide every year. Diseases caused by sexually transmitted infections (STI) in a strict sense are syphilis, gonorrhea, lymphogranuloma venereum, granuloma inguinale, and chancroid. In a wider sense, all illnesses are included which can mainly be transmitted through sexual contact. The term "sexual contact" has to be seen widely, from close physical contact to all variants of sexual behavior. This CME article is an overview of the most common occurring sexually transmitted infections in clinical practice. Both, basic knowledge as well as recent developments are discussed below. PMID:24889293

  10. Sensitivity of mechanically transmitted pathogens to different disinfectants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The intensive hands-on activities of greenhouse tomato propagation and production favor the spread of mechanically transmitted pathogens, particularly Clavibacter michiganensis subsp. michiganensis (Cmm), viruses, viroids, and Botrytis cinerea. These pathogens can spread during crop handling, graft...

  11. Multiple direction vibration fixture

    SciTech Connect

    Cericola, F.; Doggett, J.W.; Ernest, T.L.

    1991-08-27

    An apparatus is discussed for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 {degrees} around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  12. Multiple direction vibration fixture

    SciTech Connect

    Cericola, F.; Doggett, J.W.; Ernest, T.L.; Priddy, T.G.

    1990-03-21

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis. 1 fig.

  13. Multiple direction vibration fixture

    DOEpatents

    Cericola, Fred; Doggett, James W.; Ernest, Terry L.; Priddy, Tommy G.

    1991-01-01

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  14. Vibration induced white-feet: Overview and field study of vibration exposure and reported symptoms in workers

    PubMed Central

    Eger, Tammy; Thompson, Aaron; Leduc, Mallorie; Krajnak, Kristine; Goggins, Katie; Godwin, Alison; House, Ron

    2015-01-01

    BACKGROUND Workers who stand on platforms or equipment that vibrate are exposed to foot-transmitted vibration (FTV). Exposure to FTV can lead to vibration white feet/toes resulting in blanching of the toes, and tingling and numbness in the feet and toes. OBJECTIVES The objectives are 1) to review the current state of knowledge of the health risks associated with foot-transmitted vibration (FTV), and 2) to identify the characteristics of FTV and discuss the associated risk of vibration-induced injury. PARTICIPANTS Workers who operated locomotives (n = 3), bolting platforms (n = 10), jumbo drills (n = 7), raise drilling platforms (n = 4), and crushers (n = 3), participated. METHODS A tri-axial accelerometer was used to measure FTV in accordance with ISO 2631-1 guidelines. Frequency-weighted root-mean-square acceleration and the dominant frequency are reported. Participants were also asked to report pain/ache/discomfort in the hands and/or feet. RESULTS Reports of pain/discomfort/ache were highest in raise platform workers and jumbo drill operators who were exposed to FTV in the 40 Hz and 28 Hz range respectively. Reports of discomfort/ache/pain were lowest in the locomotive and crusher operators who were exposed to FTV below 10 Hz. These findings are consistent with animal studies that have shown vascular and neural damage in exposed appendages occurs at frequencies above 40 Hz. CONCLUSIONS Operators exposed to FTV at 40 Hz appear to be at greater risk of experiencing vibration induced injury. Future research is required to document the characteristics of FTV and epidemiological evidence is required to link exposure with injury. PMID:24004754

  15. [The prevention of vibration disease].

    PubMed

    Shinev, V G; Komleva, L M; Fedorov, A V; Zhuravlev, A B

    1992-01-01

    Probable cooling of hands must be taken into account in setting up the prophylaxis of pathology due to the local vibration. Warm air pumped into the manual pneumatic devices can eliminate the cooling of operators' hands. The same effect is gained by the physiotherapeutic procedure--the warming and micromassage of hands by the dry air. PMID:1295788

  16. Sexually transmitted diseases.

    PubMed

    Bechtel, Mark A; Trout, Wayne

    2015-03-01

    Sexually transmitted diseases (STDs) continue to be a global epidemic with significant risk of morbidity/mortality for the fetus. STDs with prominent cutaneous findings including condylomata acuminata, genital herpes infections, and syphilis are reviewed. Important clinical cutaneous findings help aid early diagnosis and facilitate treatment. Condylomata acuminata have the potential of causing cervical cancer, anogenital cancer, and oropharyngeal cancer. Significant advances have been made in human papilloma virus vaccinations and treatment. Genital herpes infection can produce significant physical and emotional distress to the patient and significant potential harm to the fetus. Early clinical recognition of STDs and their appropriate management is critical. PMID:25565081

  17. DOT Transmit Module

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Gin, Jonathan W.; Sahasrabudhe, Adit; Patawaran, Ferze D.; Nguyen, Danh H.; Nguyen, Huy

    2013-01-01

    The Deep Space Optical Terminal (DOT) transmit module demonstrates the DOT downlink signaling in a flight electronics assembly that can be qualified for deep space. The assembly has the capability to generate an electronic pulse-position modulation (PPM) waveform suitable for driving a laser assembly to produce the optical downlink signal. The downlink data enters the assembly through a serializer/ deserializer (SERDES) interface, and is encoded using a serially concatenated PPM (SCPPM) forward error correction code. The encoded data is modulated using PPM with an inter-symbol guard time to aid in receiver synchronization. Monitor and control of the assembly is via a low-voltage differential signal (LVDS) interface

  18. Gyrotron transmitting tube

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G. (Inventor)

    1983-01-01

    An RF transmitting tube for the 20 GHz to 500 GHz range comprises a gyrotron and a multistage depressed collector. A winding provides a magnetic field which acts on spent, spinning or orbiting electrons changing their motion to substantially forward linear motion in a downstream direction. The spent electrons then pass through a focusser into the collector. Nearly all of the electrons injected into the collector will remain within an imaginary envelope as they travel forward toward the end collector plate. The apertures in the collector plates are at least as large in diameter as the envelope at any particular axial position.

  19. SEXUALLY TRANSMITTED DISEASES SURVEILLANCE SYSTEM

    EPA Science Inventory

    The Sexually Transmitted Disease Surveillance System presents statistics and trends for sexually transmitted diseases (STDs). Data demonstrate details which provide information about STD morbidity in the United States, STD prevalence with subgroups and populations which are the f...

  20. Long-term daily vibration exposure alters current perception threshold (CPT) sensitivity and myelinated axons in a rat-tail model of vibration-induced injury.

    PubMed

    Krajnak, Kristine; Raju, Sandya G; Miller, G Roger; Johnson, Claud; Waugh, Stacey; Kashon, Michael L; Riley, Danny A

    2016-01-01

    Repeated exposure to hand-transmitted vibration through the use of powered hand tools may result in pain and progressive reductions in tactile sensitivity. The goal of the present study was to use an established animal model of vibration-induced injury to characterize changes in sensory nerve function and cellular mechanisms associated with these alterations. Sensory nerve function was assessed weekly using the current perception threshold test and tail-flick analgesia test in male Sprague-Dawley rats exposed to 28 d of tail vibration. After 28 d of exposure, Aβ fiber sensitivity was reduced. This reduction in sensitivity was partly attributed to structural disruption of myelin. In addition, the decrease in sensitivity was also associated with a reduction in myelin basic protein and 2',3'- cyclic nucleotide phosphodiasterase (CNPase) staining in tail nerves, and an increase in circulating calcitonin gene-related peptide (CGRP) concentrations. Changes in Aβ fiber sensitivity and CGRP concentrations may serve as early markers of vibration-induced injury in peripheral nerves. It is conceivable that these markers may be utilized to monitor sensorineural alterations in workers exposed to vibration to potentially prevent additional injury. PMID:26852665

  1. Vibration manual

    NASA Technical Reports Server (NTRS)

    Green, C.

    1971-01-01

    Guidelines of the methods and applications used in vibration technology at the MSFC are presented. The purpose of the guidelines is to provide a practical tool for coordination and understanding between industry and government groups concerned with vibration of systems and equipments. Topics covered include measuring, reducing, analyzing, and methods for obtaining simulated environments and formulating vibration specifications. Methods for vibration and shock testing, theoretical aspects of data processing, vibration response analysis, and techniques of designing for vibration are also presented.

  2. Sexually transmitted viruses.

    PubMed Central

    Rapp, F.

    1989-01-01

    Human viruses known to be spread by sexual contact include herpes simplex viruses (HSV), papillomaviruses (HPV), human immunodeficiency virus (HIV), hepatitis B virus, and cytomegalovirus. Infections with the first three (HSV, HPV, and HIV) have reached epidemic proportions and pose global health concerns. Most of what we know about these human pathogens has been learned only recently, owing to the advent of DNA technologies and advances in culture techniques. In fact, our awareness of one virally transmitted venereal disease, acquired immunodeficiency syndrome, dates to the early 1980s. This paper touches on various aspects of the biology, pathogenesis, clinical manifestations, and, where applicable, oncogenicity of these agents, as well as current treatments and vaccine initiatives. PMID:2549736

  3. Hand Washing

    MedlinePlus

    ... dirty little secrets: Students don't wash their hands often or well. In one study, only 58% of female and 48% of male middle- and high-school students washed their hands after using the bathroom. Yuck! previous continue How ...

  4. Hand washing.

    PubMed

    2016-07-01

    A surgery matron has writt en a hand hygiene promotional video rap to encourage staff, patients and visitors to wash their hands. Vicky Cartwright from University Hospitals of Leicester NHS Trust rewrote the lyrics to 1990s hit rap, Ice Ice Baby. PMID:27380706

  5. Robotic Hand

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Omni-Hand was developed by Ross-Hime Designs, Inc. for Marshall Space Flight Center (MSFC) under a Small Business Innovation Research (SBIR) contract. The multiple digit hand has an opposable thumb and a flexible wrist. Electric muscles called Minnacs power wrist joints and the interchangeable digits. Two hands have been delivered to NASA for evaluation for potential use on space missions and the unit is commercially available for applications like hazardous materials handling and manufacturing automation. Previous SBIR contracts resulted in the Omni-Wrist and Omni-Wrist II robotic systems, which are commercially available for spray painting, sealing, ultrasonic testing, as well as other uses.

  6. Diseases Transmitted by Cats.

    PubMed

    Goldstein, Ellie J C; Abrahamian, Fredrick M

    2015-10-01

    Humans and cats have shared a close relationship since ancient times. Millions of cats are kept as household pets, and 34% of households have cats. There are numerous diseases that may be transmitted from cats to humans. General modes of transmission, with some overlapping features, can occur through inhalation (e.g., bordetellosis); vector-borne spread (e.g., ehrlichiosis); fecal-oral route (e.g., campylobacteriosis); bite, scratch, or puncture (e.g., rabies); soil-borne spread (e.g., histoplasmosis); and direct contact (e.g., scabies). It is also likely that the domestic cat can potentially act as a reservoir for many other zoonoses that are not yet recognized. The microbiology of cat bite wound infections in humans is often polymicrobial with a broad mixture of aerobic (e.g., Pasteurella, Streptococcus, Staphylococcus) and anaerobic (e.g., Fusobacterium, Porphyromonas, Bacteroides) microorganisms. Bacteria recovered from infected cat bite wounds are most often reflective of the oral flora of the cat, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. PMID:26542039

  7. Hand Eczema

    PubMed Central

    Agarwal, Uma Shankar; Besarwal, Raj Kumar; Gupta, Rahul; Agarwal, Puneet; Napalia, Sheetal

    2014-01-01

    Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients. PMID:24891648

  8. Novel active vibration absorber with magnetorheological fluid

    NASA Astrophysics Data System (ADS)

    Gerlach, T.; Ehrlich, J.; Böse, H.

    2009-02-01

    Disturbing vibrations diminish the performance of technical high precision devices significantly. In search of a suitable solution for reducing these vibrations, a novel concept of active vibration reduction was developed which exploits the special properties of magnetorheological fluids. In order to evaluate the concept of such an active vibration absorber (AVA) a demonstrator was designed and manufactured. This demonstrator generates a force which counteracts the motion of the vibrating body. Since the counterforce is generated by a centrifugal exciter, the AVA provides the capability to compensate vibrations even in two dimensions. To control the strength of the force transmitted to the vibrating body, the exciter is based on a tunable MR coupling. The AVA was integrated in an appropriate testing device to investigate its performance. The recorded results show a significant reduction of the vibration amplitudes by an order of magnitude.

  9. Photonic crystal with left-handed components

    NASA Astrophysics Data System (ADS)

    Markoš, Peter

    2016-02-01

    We show that the periodic array of left-handed cylinders possesses a rich spectrum of guided modes when the negative permeability of cylinders equals exactly to minus value of permeability of embedding media. These resonances strongly influence propagation of electromagnetic waves through photonic structures made from left-handed materials. A series of Fano resonances excited by incident wave destroys the band frequency spectrum of square array of left-handed cylinders and increases considerably the absorption of transmitted waves.

  10. Statistics, Uncertainty, and Transmitted Variation

    SciTech Connect

    Wendelberger, Joanne Roth

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  11. Sexually transmitted diseases in Indonesia.

    PubMed Central

    Harahap, M

    1980-01-01

    Epidemiological factors and changing ecological conditions have greatly facilitated the spread of sexually transmitted diseases and led to their rising incidence in Indonesia. Gonorrhoea is at present very prevalent, and drug resistance among circulating strains of gonococci is a contributing factor. Despite medical advances in both diagnosis and treatment of sexually transmitted diseases, these are becoming commoner; unlike other communicable diseases they have so far defied efforts to control them. PMID:6893569

  12. Circumcision and sexually transmitted diseases.

    PubMed Central

    Cook, L S; Koutsky, L A; Holmes, K K

    1994-01-01

    OBJECTIVES. New evidence linking lack of circumcision with sexually transmitted human immunodeficiency virus revives concerns about circumcision and other sexually transmitted diseases. This study was undertaken to assess the relationship between circumcision and syphilis, gonorrhea, chlamydial infection, genital herpes, nongonococcal urethritis, and exophytic genital warts. METHODS. A cross-sectional study of 2776 heterosexual men attending a sexually transmitted disease clinic in 1988 was used to investigate the relationship between circumcision and sexually transmitted diseases. Subjects with specific sexually transmitted diseases and those without such diseases were compared after adjustment for age, race, zip code of residence, other sexually transmitted diseases, and number of sexual partners. RESULTS. A positive relationship was observed between uncircumcised status and both syphilis and gonorrhea. A negative relationship was found between warts and lack of circumcision. No apparent relationship was noted between uncircumcised status and genital herpes, chlamydial infection, or nongonococcal urethritis. CONCLUSIONS. Uncircumcised men were more likely than circumcised men to have syphilis and gonorrhea and were less likely to have visible warts. PMID:8296939

  13. Laboratory and field measurements and evaluations of vibration at the handles of riveting hammers

    PubMed Central

    McDOWELL, THOMAS W.; WARREN, CHRISTOPHER; WELCOME, DANIEL E.; DONG, REN G.

    2015-01-01

    The use of riveting hammers can expose workers to harmful levels of hand-transmitted vibration (HTV). As a part of efforts to reduce HTV exposures through tool selection, the primary objective of this study was to evaluate the applicability of a standardized laboratory-based riveting hammer assessment protocol for screening riveting hammers. The second objective was to characterize the vibration emissions of reduced vibration riveting hammers and to make approximations of the HTV exposures of workers operating these tools in actual work tasks. Eight pneumatic riveting hammers were selected for the study. They were first assessed in a laboratory using the standardized method for measuring vibration emissions at the tool handle. The tools were then further assessed under actual working conditions during three aircraft sheet metal riveting tasks. Although the average vibration magnitudes of the riveting hammers measured in the laboratory test were considerably different from those measured in the field study, the rank orders of the tools determined via these tests were fairly consistent, especially for the lower vibration tools. This study identified four tools that consistently exhibited lower frequency-weighted and unweighted accelerations in both the laboratory and workplace evaluations. These observations suggest that the standardized riveting hammer test is acceptable for identifying tools that could be expected to exhibit lower vibrations in workplace environments. However, the large differences between the accelerations measured in the laboratory and field suggest that the standardized laboratory-based tool assessment is not suitable for estimating workplace riveting hammer HTV exposures. Based on the frequency-weighted accelerations measured at the tool handles during the three work tasks, the sheet metal mechanics assigned to these tasks at the studied workplace are unlikely to exceed the daily vibration exposure action value (2.5 m s−2) using any of the

  14. Texture-induced vibrations in the forearm during tactile exploration

    PubMed Central

    Delhaye, Benoit; Hayward, Vincent; Lefèvre, Philippe; Thonnard, Jean-Louis

    2012-01-01

    Humans can detect and discriminate between fine variations of surface roughness using active touch. It is hitherto believed that roughness perception is mediated mostly by cutaneous and subcutaneous afferents located in the fingertips. However, recent findings have shown that following abolishment of cutaneous afferences resulting from trauma or pharmacological intervention, the ability of subjects to discriminate between textures roughness was not significantly altered. These findings suggest that the somatosensory system is able to collect textural information from other sources than fingertip afference. It follows that signals resulting of the interaction of a finger with a rough surface must be transmitted to stimulate receptor populations in regions far away from the contact. This transmission was characterized by measuring in the wrist vibrations originating at the fingertip and thus propagating through the finger, the hand and the wrist during active exploration of textured surfaces. The spectral analysis of the vibrations taking place in the forearm tissues revealed regularities that were correlated with the scanned surface and the speed of exploration. In the case of periodic textures, the vibration signal contained a fundamental frequency component corresponding to the finger velocity divided by the spatial period of the stimulus. This regularity was found for a wide range of textural length scales and scanning velocities. For non-periodic textures, the spectrum of the vibration did not contain obvious features that would enable discrimination between the different stimuli. However, for both periodic and non-periodic stimuli, the intensity of the vibrations could be related to the microgeometry of the scanned surfaces. PMID:22783177

  15. Vibrational rainbows

    SciTech Connect

    Drolshagen, G.; Mayne, H.R.; Toennies, J.P.

    1981-07-01

    We extend the theory of inelastic rainbows to include vibrationally inelastic scattering, showing how the existence of vibrational rainbows can be deduced from collinear classical scattering theory. Exact close-coupling calculations are carried out for a breathing sphere potential, and rainbow structures are, in fact, observed. The location of the rainbows generally agrees well with the classical prediction. In addition, the sensitivity of the location of the rainbow to changes in the vibrational coupling has been investigated. It is shown that vibrational rainbows persist in the presence of anisotropy. Experimental results (R. David, M. Faubel, and J. P. Toennies, Chem. Phys. Lett. 18, 87 (1973)) are examined for evidence of vibrational rainbow structure, and it is shown that vibrational rainbow theory is not inconsistent with these results.

  16. Hand rejuvenation.

    PubMed

    Riyaz, Farhaad R; Ozog, David

    2015-09-01

    Aging of the hands results from both natural processes and chronic ultraviolet light exposure. Together, these cause textural and pigmentary changes, excess skin laxity, rhytides, and soft tissue atrophy that presents as prominent bones and tendons with easily visible veins. Many options are available for the reversal of these changes. Photoaging can be improved with chemical peels and light-based treatments (such as Q-switched lasers), resurfacing lasers, intense pulsed light, and photodynamic therapy. Soft tissue atrophy can be corrected with autologous fat, nonanimal stabilized hyaluronic acid, calcium hydroxylapatite, and poly-L lactic acid injections. The literature shows that these treatments have favorable outcomes for most patients; but in order to reduce known complications, it is important to understand the proper use and limitations of each modality. PMID:26566571

  17. [Sexually transmitted infections and spermicides].

    PubMed

    Driák, Daniel

    2012-01-01

    Incidence of sexually transmitted infections (diseases) has been already increasing again for more than one decade; the world number of 125-340 millions of new cases a year is estimated. Fifteen thousands of new HIV-positive persons daily present a substantial contribution to the total amount. Besides an increasing number of unplanned pregnancies, the huge spreading of sexually transmitted infections predominantly of the second generation is the main reason for a renewed interest in search of local contraceptives, i.e. spermicides. An urgent need for a new, non-detergent, synthetic or natural spermicide emerged to replace the traditional nonoxynol-9. New preparation of microbicidal spermicide should offer dual protection against both unplanned conception and sexually transmitted infections. PMID:23256629

  18. Vibration isolation

    NASA Technical Reports Server (NTRS)

    Bastin, Paul

    1990-01-01

    Viewgraphs on vibration isolation are presented. Techniques to control and isolate centrifuge disturbances were identified. Topics covered include: disturbance sources in the microgravity environment; microgravity assessment criteria; life sciences centrifuge; flight support equipment for launch; active vibration isolation system; active balancing system; and fuzzy logic control.

  19. VIBRATION COMPACTION

    DOEpatents

    Hauth, J.J.

    1962-07-01

    A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

  20. Vibrational Coupling

    SciTech Connect

    2011-01-01

    By homing in on the distribution patterns of electrons around an atom, a team of scientists team with Berkeley Lab's Molecular Foundry showed how certain vibrations from benzene thiol cause electrical charge to "slosh" onto a gold surface (left), while others do not (right). The vibrations that cause this "sloshing" behavior yield a stronger SERS signal.

  1. Helicopter rotor blade design for minimum vibration

    NASA Technical Reports Server (NTRS)

    Taylor, R. B.

    1984-01-01

    The importance of blade design parameters in rotor vibratory response and the design of a minimum vibration blade based upon this understanding are examined. Various design approaches are examined for a 4 bladed articulated rotor operating at a high speed flight condition. Blade modal shaping, frequency placement, structural and aerodynamic coupling, and intermodal cancellation are investigated to systematically identify and evaluate blade design parameters that influence blade airloads, blade modal response, hub loads, and fuselage vibration. The relative contributions of the various components of blade force excitation and response to the vibratory hub loads transmitted to the fuselage are determined in order to isolate primary candidates for vibration alleviation. A blade design is achieved which reduces the predicted fuselage vibration from the baseline blade by approximately one half. Blade designs are developed that offer significant reductions in vibration (and fatigue stresses) without resorting to special vibration alleviation devices, radical blade geometries, or weight penalties.

  2. Actively controlled vibration welding system and method

    SciTech Connect

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  3. Analyses of biodynamic responses of seated occupants to uncorrelated fore-aft and vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Mandapuram, Santosh; Rakheja, Subhash; Marcotte, Pierre; Boileau, Paul-Émile

    2011-08-01

    The apparent mass and seat-to-head-transmissibility response functions of the seated human body were investigated under exposures to fore-aft ( x), vertical ( z), and combined fore-aft and vertical ( x and z) axis whole-body vibration. The coupling effects of dual-axis vibration were investigated using two different frequency response function estimators based upon the cross- and auto-spectral densities of the response and excitation signals, denoted as H1 and Hv estimators, respectively. The experiments were performed to measure the biodynamic responses to single and uncorrelated dual-axis vibration, and to study the effects of hands support, back support and vibration magnitude on the body interactions with the seatpan and the backrest, characterized in terms of apparent masses and the vibration transmitted to the head. The data were acquired with 9 subjects exposed to two different magnitudes of vibration applied along the individual x- and z-axis (0.25 and 0.4 m/s 2 rms), and along both the axis (0.28 and 0.4 m/s 2 rms along each axis) in the 0.5-20 Hz frequency range. The two methods resulted in identical single-axis responses but considerably different dual-axis responses. The dual-axis responses derived from the Hv estimator revealed notable effects of dual-axis vibration, as they comprised both the direct and cross-axis responses observed under single axis vibration. Such effect, termed as the coupling effect, was not evident in the dual-axis responses derived using the commonly used H1 estimator. The results also revealed significant effects of hands and back support conditions on the coupling effects and the measured responses. The back support constrained the upper body movements and thus showed relatively weaker coupling compared to that observed in the responses without the back support. The effect of hand support was also pronounced under the fore-aft vibration. The results suggest that a better understanding of the seated human body responses to

  4. Materials Testing in Long Cane Design: Sensitivity, Flexibility, and Transmission of Vibration

    ERIC Educational Resources Information Center

    Rodgers, Mark D.; Emerson, Robert Wall

    2005-01-01

    Different materials that are used in manufacturing long cane shafts were assessed for their ability to transmit vibration and their sensitivity to tactile information, flexibility, and durability. It was found that the less flexible a cane shaft is, the better it transmits vibrations that are useful for discriminating surface textures and that…

  5. Nematode infections: soil-transmitted helminths and trichinella.

    PubMed

    Knopp, Stefanie; Steinmann, Peter; Keiser, Jennifer; Utzinger, Jürg

    2012-06-01

    Infection with soil-transmitted helminths occurs via ingestion of nematode eggs with contaminated food and water, via hands, or inhalation of dust, or by penetration of larvae through the skin. Trichinella infections are caused by the ingestion of larvae contained in undercooked meat. In highly endemic areas, preventive chemotherapy (ie, regular administration of anthelmintic drugs to at-risk populations) is the key strategy against soil-transmitted helminthiasis. Integrated control approaches, including improved hygiene, sanitation, and water, are required for lasting effects. Because of growing tourism, travel, and migration, clinicians and specialized travel clinics must remain aware of the diagnosis, prevention, and treatment of soil-transmitted helminth and Trichinella infections. PMID:22632643

  6. Laser-Based Measurement Of Torsional Vibration

    NASA Astrophysics Data System (ADS)

    Eastwood, P. G.; Halliwell, N. A.

    1986-07-01

    Investigations of the torsional vibration characteristics of shaft systems which transmit pulsating torques are an important part of a machinery designer's responsibility. Satisfactory operation of such systems depends to a large extent on successful treatment of this vibration problem, since incorrectly or insufficiently controlled torsional oscillations can lead to fatigue failure, rapid bearing wear, gear hammer etc. The problem is particularly severe in engine crankshaft design where numerous failures have been traced to abnormal vibration at "critical" speeds. Traditionally, the monitoring of torsional oscillation has been performed using strain gauges, slip rings and a variety of mechanical and electrical "torsiographs". More recently systems employing slotted discs or toothed wheels together with proximity transducers have been preferred, but a disadvantage arises from all these methods in that they require contact with the rotating component which necessitates "downtime" for transducer attachment. Moreover, physical access to the rotating surface is often restricted thus making the use of such methods impractical. The "cross-beam" laser velocimeter provides a means of measuring torsional vibration by a non-contact method, thus effectively overcoming the disadvantages of previous measurement systems. This well established laser-based instrument provides a time-resolved voltage analogue of shaft tangential surface velocity and laboratory and field tests have shown it to be both accurate and reliable. The versatility of this instrument, however, is restricted by the need for accurate positioning, since the velocimeter must be arranged so that the rotating surface always traverses the beam intersection region, which is typically only a fraction of a millimetre in length. As a consequence use is restricted to components of circular cross section. This paper compares and contrasts the "cross-beam" system with a new laser instrument, the laser torsional vibrometer

  7. Phasic activity in the human erector spinae during repetitive hand movements.

    PubMed Central

    Zedka, M; Prochazka, A

    1997-01-01

    1. Phasic activity in the human back muscle erector spinae (ES) was studied during repetitive hand movements. The hand movements were elicited voluntarily by the subject or induced passively by the experimenter through a servomotor or through cyclical electrical stimulation of muscles acting about the wrist. The aim of the study was to determine whether the rhythmical activation of ES was of supraspinal, intersegmental or segmental origin. 2. When voluntary rhythmical hand movements were performed as fast as possible, cyclical ES EMG bursts occurred at the same frequency. This frequency was significantly higher than that reached when the task was to contract the back muscles as rapidly as possible. This suggests that the ES activity during the fast hand movements was not generated by direct commands descending to the ES muscles from the motor area of the cerebral cortex responsible for voluntary back muscle activation. 3. During imposed rhythmical hand movements, ES EMG bursts remained entrained to the hand movements, even when movement frequencies far exceeded those attainable voluntarily either for the hand or the back. This showed that ES EMG responses could be evoked by the hand movements even when these were not generated by descending neural commands. Two alternative mechanisms of ES activation were considered: (a) propriospinal transmission of afferent input entering the spinal cord from the upper extremity; (b) afferent input from ES and other trunk muscles, responding to local oscillations transmitted mechanically from the hand to the lower back. 4. Activation of ES via proprioceptive signals from the forearm was unlikely since (a) simultaneous electrical stimulation of wrist extensor and wrist flexor muscles did not result in repetitive ES EMG bursting; (b) cyclical vibration of the wrist extensors did not evoke ES EMG bursting; (c) when the forearm was constrained and the hand was moved passively, the lower trunk accelerations and cyclical ES EMG both

  8. Vibration generators

    SciTech Connect

    Lerwill, W.E.

    1980-09-16

    Apparatus for generating vibrations in a medium, such as the ground, comprises a first member which contacts the medium, means , preferably electromagnetic, which includes two relatively movable members for generating vibrations in the apparatus and means operatively connecting the said two members to said first member such that the relatively amplitudes of the movements of said three members can be adjusted to match the impedances of the apparatus and the medium.

  9. Vibration sensors

    NASA Astrophysics Data System (ADS)

    Gupta, Amita; Singh, Ranvir; Ahmad, Amir; Kumar, Mahesh

    2003-10-01

    Today, vibration sensors with low and medium sensitivities are in great demand. Their applications include robotics, navigation, machine vibration monitoring, isolation of precision equipment & activation of safety systems e.g. airbags in automobiles. Vibration sensors have been developed at SSPL, using silicon micromachining to sense vibrations in a system in the 30 - 200 Hz frequency band. The sensing element in the silicon vibration sensor is a seismic mass suspended by thin silicon hinges mounted on a metallized glass plate forming a parallel plate capacitor. The movement of the seismic mass along the vertical axis is monitored to sense vibrations. This is obtained by measuring the change in capacitance. The movable plate of the parallel plate capacitor is formed by a block connected to a surrounding frame by four cantilever beams located on sides or corners of the seismic mass. This element is fabricated by silicon micromachining. Several sensors in the chip sizes 1.6 cm x 1.6 cm, 1 cm x 1 cm and 0.7 cm x 0.7 cm have been fabricated. Work done on these sensors, techniques used in processing and silicon to glass bonding are presented in the paper. Performance evaluation of these sensors is also discussed.

  10. Vocal Dose Measures: Quantifying Accumulated Vibration Exposure in Vocal Fold Tissues

    PubMed Central

    Titze, Ingo R.; Švec, Jan G.; Popolo, Peter S.

    2011-01-01

    To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses. PMID:12959470

  11. Using Piezoelectric Devices to Transmit Power through Walls

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi

    2008-01-01

    A method denoted wireless acoustic-electric feed-through (WAEF) has been conceived for transmitting power and/or data signals through walls or other solid objects made of a variety of elastic materials that could be electrically conductive or nonconductive. WAEF would make it unnecessary to use wires, optical fibers, tubes, or other discrete wall-penetrating signal-transmitting components, thereby eliminating the potential for structural weakening or leakage at such penetrations. Avoidance of such penetrations could be essential in some applications in which maintenance of pressure, vacuum, or chemical or biological isolation is required. In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall would be driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall would convert the vibrations back to an ultrasonic AC electric signal, which would then be detected and otherwise processed in a manner that would depend on the modulation (if any) applied to the signal and whether the signal was used to transmit power, data, or both. An electromechanical-network model has been derived as a computationally efficient means of analyzing and designing a WAEF system. This model is a variant of a prior model, known in the piezoelectric-transducer art as Mason's equivalent-circuit model, in which the electrical and mechanical dynamics, including electromechanical couplings, are expressed as electrical circuit elements that can include inductors, capacitors, and lumped-parameter complex impedances. The real parts of the complex impedances are used to account for dielectric, mechanical, and coupling losses in all components (including all piezoelectric-transducer, wall, and intermediate material layers). In an application to a three-layer piezoelectric structure, this model was shown to yield the same results as do solutions of the wave equations of piezoelectricity and acoustic

  12. Compact Active Vibration Control System for a Flexible Panel

    NASA Technical Reports Server (NTRS)

    Schiller, Noah H. (Inventor); Cabell, Randolph H. (Inventor); Perey, Daniel F. (Inventor)

    2014-01-01

    A diamond-shaped actuator for a flexible panel has an inter-digitated electrode (IDE) and a piezoelectric wafer portion positioned therebetween. The IDE and/or the wafer portion are diamond-shaped. Point sensors are positioned with respect to the actuator and measure vibration. The actuator generates and transmits a cancelling force to the panel in response to an output signal from a controller, which is calculated using a signal describing the vibration. A method for controlling vibration in a flexible panel includes connecting a diamond-shaped actuator to the flexible panel, and then connecting a point sensor to each actuator. Vibration is measured via the point sensor. The controller calculates a proportional output voltage signal from the measured vibration, and transmits the output signal to the actuator to substantially cancel the vibration in proximity to each actuator.

  13. Hand lotion poisoning

    MedlinePlus

    Hand lotion poisoning occurs when someone swallows hand lotion or hand cream. This article is for information only. DO ... These ingredients in hand lotion or cream can be harmful if swallowed: Dimethicone Mineral oil Paraffins (waxes) Petrolatum Various alcohols

  14. The effects of repetitive vibration on sensorineural function: biomarkers of sensorineural injury in an animal model of metabolic syndrome

    PubMed Central

    Kiedrowski, Megan; Waugh, Stacey; Miller, Roger; Johnson, Claud; Krajnak, Kristine

    2016-01-01

    Exposure to hand-transmitted vibration in the work-place can result in the loss of sensation and pain in workers. These effects may be exacerbated by pre-existing conditions such as diabetes or the presence of primary Raynaud's phenomena. The goal of these studies was to use an established model of vibration-induced injury in Zucker rats. Lean Zucker rats have a normal metabolic profile, while obese Zucker rats display symptoms of metabolic disorder or Type II diabetes. This study examined the effects of vibration in obese and lean rats. Zucker rats were exposed to 4 h of vibration for 10 consecutive days at a frequency of 125 Hz and acceleration of 49 m/s2 for 10 consecutive days. Sensory function was checked using transcutaneous electrical stimulation on days 1, 5 and 9 of the exposure. Once the study was complete the ventral tail nerves, dorsal root ganglia and spinal cord were dissected, and levels of various transcripts involved in sensorineural dysfunction were measured. Sensorineural dysfunction was assessed using transcutaneous electrical stimulation. Obese Zucker rats displayed very few changes in sensorineural function. However they did display significant changes in transcript levels for factors involved in synapse formation, peripheral nerve remodeling, and inflammation. The changes in transcript levels suggested that obese Zucker rats had some level of sensory nerve injury prior to exposure, and that exposure to vibration activated pathways involved in injury and re-innervation. PMID:26433044

  15. The effects of repetitive vibration on sensorineural function: biomarkers of sensorineural injury in an animal model of metabolic syndrome.

    PubMed

    Kiedrowski, Megan; Waugh, Stacey; Miller, Roger; Johnson, Claud; Krajnak, Kristine

    2015-11-19

    Exposure to hand-transmitted vibration in the work-place can result in the loss of sensation and pain in workers. These effects may be exacerbated by pre-existing conditions such as diabetes or the presence of primary Raynaud's phenomena. The goal of these studies was to use an established model of vibration-induced injury in Zucker rats. Lean Zucker rats have a normal metabolic profile, while obese Zucker rats display symptoms of metabolic disorder or Type II diabetes. This study examined the effects of vibration in obese and lean rats. Zucker rats were exposed to 4h of vibration for 10 consecutive days at a frequency of 125 Hz and acceleration of 49 m/s(2) for 10 consecutive days. Sensory function was checked using transcutaneous electrical stimulation on days 1, 5 and 9 of the exposure. Once the study was complete the ventral tail nerves, dorsal root ganglia and spinal cord were dissected, and levels of various transcripts involved in sensorineural dysfunction were measured. Sensorineural dysfunction was assessed using transcutaneous electrical stimulation. Obese Zucker rats displayed very few changes in sensorineural function. However they did display significant changes in transcript levels for factors involved in synapse formation, peripheral nerve remodeling, and inflammation. The changes in transcript levels suggested that obese Zucker rats had some level of sensory nerve injury prior to exposure, and that exposure to vibration activated pathways involved in injury and re-innervation. PMID:26433044

  16. Random Vibrations

    NASA Technical Reports Server (NTRS)

    Messaro. Semma; Harrison, Phillip

    2010-01-01

    Ares I Zonal Random vibration environments due to acoustic impingement and combustion processes are develop for liftoff, ascent and reentry. Random Vibration test criteria for Ares I Upper Stage pyrotechnic components are developed by enveloping the applicable zonal environments where each component is located. Random vibration tests will be conducted to assure that these components will survive and function appropriately after exposure to the expected vibration environments. Methodology: Random Vibration test criteria for Ares I Upper Stage pyrotechnic components were desired that would envelope all the applicable environments where each component was located. Applicable Ares I Vehicle drawings and design information needed to be assessed to determine the location(s) for each component on the Ares I Upper Stage. Design and test criteria needed to be developed by plotting and enveloping the applicable environments using Microsoft Excel Spreadsheet Software and documenting them in a report Using Microsoft Word Processing Software. Conclusion: Random vibration liftoff, ascent, and green run design & test criteria for the Upper Stage Pyrotechnic Components were developed by using Microsoft Excel to envelope zonal environments applicable to each component. Results were transferred from Excel into a report using Microsoft Word. After the report is reviewed and edited by my mentor it will be submitted for publication as an attachment to a memorandum. Pyrotechnic component designers will extract criteria from my report for incorporation into the design and test specifications for components. Eventually the hardware will be tested to the environments I developed to assure that the components will survive and function appropriately after exposure to the expected vibration environments.

  17. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  18. Monolithic 20-GHz Transmitting Module

    NASA Technical Reports Server (NTRS)

    Kascak, T.; Kaelin, G.; Gupta, A.

    1986-01-01

    20-GHz monolithic microwave/millimeter-wave integrated circuit (MMIC) with amplification and phase-shift (time-delay) capabilities developed. Use of MMIC module technology promises to make feasible development of weight- and cost-effective phased-array antenna systems, identified as major factor in achieving minimum cost and efficient use of frequency and orbital resources of future generations of communication satellite systems. Use of MMIC transmitting modules provides for relatively simple method for phase-shift control of many separate radio-frequency (RF) signals required for phased-array antenna systems.

  19. Vibration disease: plasma electrolytes and trace elements.

    PubMed

    Tzvetkov, D; Kostova, V; Razboynikova, F; Dimitrov, D; Petrov, I

    1994-01-01

    102 patients with vibration disease (mean age 46 +/- 7, length of service in different jobs using vibration tools 17 +/- 7 years) were studied. Plasma electrolytes and trace elements (sodium, potassium, calcium, magnesium, phosphorus, chloride, iron, copper, zinc, cobalt and manganese) and plasma osmolality were investigated, as well as some specific tests indicative of vibration exposure--cold provocation test, vibration sense, thermoasymmetry (left/right hand), skin electric resistance and hand and finger blood flow (Doppler-ultrasound sonometry). In a large number of patients increased values for the following variables were found--magnesium in 43%, zinc in 45%, cobalt in 57%, manganese in 70% and plasma osmolality in 66%. It is suggested that vibration affects mineral metabolism. However, these disturbances in mineral metabolism are secondary to other pathological changes in the body. PMID:8029523

  20. [Sexually transmitted diseases and travel].

    PubMed

    Halioua, B; Prazuck, T; Malkin, J E

    1997-01-01

    Travelers are highly exposed to acquiring sexually transmitted diseases especially since the most popular destinations are high risk areas. While this risk applies to all travelers, it is highest for the "sex" tourist who is typically a male with a mean age of 38 years. Awareness of risks is still incomplete, especially with regard to HIV. Several studies have shown that only 20% to 70% of travelers use condoms. This finding accounts for the high incidence of sexually transmitted diseases in returning travelers: 2% to 10%. The risk of HIV infection is particularly high for persons living abroad. Based on available data, we can define the typical profile of the high risk traveler who should be targeted for prevention. Prevention depends on providing adequate information before departure, especially concerning HIV infection. Use of a condom throughout sexual contact is a basic safety rule. However condom quality is poor in many developing countries. Returning travelers should seek medical advice if manifestations involving the anogenital regions should appear. PMID:9612761

  1. Sexually transmitted infections, pregnancy, and breastfeeding

    MedlinePlus

    ... please visit OPA . '); Sexually transmitted infections, pregnancy, and breastfeeding Sexually transmitted infections (STIs) are also called sexually ... from mother to baby during pregnancy and through breastfeeding. Expand All How do STIs affect pregnant women? ...

  2. Vibration on board and health effects.

    PubMed

    Jensen, Anker; Jepsen, Jørgen Riis

    2014-01-01

    There is only limited knowledge of the exposure to vibrations of ships' crews and their risk of vibration-induced health effects. Exposure to hand-arm vibrations from the use of vibrating tools at sea does not differ from that in the land-based trades. However, in contrast to most other work places, seafarers are also exposed to vibrations to the feet when standing on vibrating surfaces on board. Anecdotal reports have related the development of "white feet" to local exposure to vibration, e.g. in mining, but this connection has not been investigated in the maritime setting. As known from studies of the health consequences of whole body vibrations in land-transportation, such exposure at sea may affect ships' passengers and crews. While the relation of back disorders to high levels of whole body vibration has been demonstrated among e.g. tractor drivers, there are no reported epidemiological evidence for such relation among seafarers except for fishermen, who, however, are also exposed to additional recognised physical risk factors at work. The assessment and reduction of vibrations by naval architects relates to technical implications of this impact for the ships' construction, but has limited value for the estimation of health risks because they express the vibration intensity differently that it is done in a medical context. PMID:25231326

  3. Surface Acoustic Wave (SAW) Vibration Sensors

    PubMed Central

    Filipiak, Jerzy; Solarz, Lech; Steczko, Grzegorz

    2011-01-01

    In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit. PMID:22247694

  4. Surface acoustic wave (SAW) vibration sensors.

    PubMed

    Filipiak, Jerzy; Solarz, Lech; Steczko, Grzegorz

    2011-01-01

    In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit. PMID:22247694

  5. Sexually transmitted diseases in children in India.

    PubMed

    Dhawan, Jyoti; Gupta, Somesh; Kumar, Bhushan

    2010-01-01

    Sexually transmitted diseases (STDs) in children are not uncommon in India, though systematic epidemiological studies to determine the exact prevalence are not available. STDs in children can be acquired via sexual route or, uncommonly, via non-sexual route such as accidental inoculation by a diseased individual. Neonatal infections are almost always acquired intrauterine or during delivery. Voluntary indulgence in sexual activity is also an important factor in acquisition of STDs in childhood. Sexual abuse and sex trafficking remain the important problems in India. Surveys indicate that nearly half of the children are sexually abused. Most at risk children are street-based, homeless or those living in or near brothels. Last two decades have shown an increase in the prevalence of STDs in children, though most of the data is from northern part of the country and from major hospitals. However, due to better availability of antenatal care to majority of women, cases of congenital syphilis have declined consistently over the past two-three decades. Other bacterial STDs are also on decline. On the other hand, viral STDs such as genital herpes and anogenital warts are increasing. This reflects trends of STDs in the adult population. Concomitant HIV infection is uncommon in children. Comprehensive sex education, stringent laws to prevent sex trafficking and child sexual abuse, and antenatal screening of all the women can reduce the prevalence of STDs in children. PMID:20826987

  6. Hand Dominance and Common Hand Conditions.

    PubMed

    Lutsky, Kevin; Kim, Nayoung; Medina, Juana; Maltenfort, Mitchell; Beredjiklian, Pedro K

    2016-05-01

    The goals of this study were to (1) assess how frequently patients present for evaluation of common hand disorders in relation to hand dominance and (2) evaluate the effect of hand dominance on function in patients with these conditions. The authors hypothesized that (1) the majority of patients who seek evaluation would have a condition that affects the dominant hand, and (2) disability scores would be worse if the dominant hand is involved. They retrospectively reviewed the records of consecutive patients who presented for treatment to their institution with unilateral symptoms of 5 common disorders of the hand: carpal tunnel syndrome (CTS), de Quervain's tenosynovitis (DEQ), lateral epicondylitis (LE), hand osteoarthritis (OA), and trigger finger (TF). The authors assessed the effect of diagnosis and hand dominance on Disabilities of the Arm, Shoulder and Hand (DASH) scores. The study group comprised 1029 patients (379 men and 650 women) with a mean age of 59.5 years. Ninety percent were right-hand dominant. The dominant and nondominant hands were affected with relatively equal frequency for CTS, DEQ, OA, and TF (range, 45%-53%). Patients with LE had a significantly higher incidence of dominant hand involvement. Men had lower DASH scores than women by an average of 7.9 points, and DASH scores were significantly but slightly higher for the overall group (3.2 points) when the dominant side was affected. Men with LE and women with TF and OA had significantly higher DASH scores when their dominant extremity was affected. Common hand disorders such as CTS, DEQ, OA, and TF affect the dominant and nondominant hands in roughly equivalent proportions, whereas LE is more common on the dominant side. Dominant hand involvement results in significantly worse DASH scores, although the magnitude of this is relatively small. Women have significantly higher DASH scores than men for the conditions evaluated. [Orthopedics. 2016; 39(3):e444-e448.]. PMID:27018604

  7. VLF/LF transmitting antennas

    NASA Astrophysics Data System (ADS)

    Belrose, John S.

    1993-05-01

    Very Low Frequency (VLF) transmitting antenna design is a specialized field of engineering that requires the combined skill of radio, civil, and mechanical engineers. The antenna systems used for this band (15-30 kHz) are enormous structures. Vertical radiators with very extensive top-loading (non-radiating top-hats) are necessary because the electrical height of practical towers is small. For tower heights of 300-450 meters (1000-1500 feet) the electrical heights are only fifteen to forty-five one thousandths of a wavelength. This presentation discusses the following topics: antenna design concepts, antenna fundamentals, tools for antenna modeling, a mini-study of conventional antennas, multiple tuned antenna systems, and a comparison between performance (measured and predicted) for multiple tuned antennas vs. single tuned antennas.

  8. Transfusion-transmitted parasitic infections.

    PubMed

    Singh, Gagandeep; Sehgal, Rakesh

    2010-07-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas' disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply. PMID:20859503

  9. Transfusion-transmitted parasitic infections

    PubMed Central

    Singh, Gagandeep; Sehgal, Rakesh

    2010-01-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas’ disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply. PMID:20859503

  10. Sexually transmitted diseases and anorectum.

    PubMed

    Van Kemseke, C

    2009-01-01

    Sexually transmitted diseases (STD) are a major public health problem because their incidence is increasing worldwide despite prevention campaigns and because they raise the risk of HIV infection. Anorectal localisations of STD are common among men who have sex with men (MSM) but can also be seen among heterosexuals (men or women). Transmission of such infections is due to anal sex or to other sexual behaviours like "fisting". Although some pathogens (like Human Papillomavirus-HPV) are common in gastroenterologist/proctologist consultations, others are not so well-known. Furthermore during the last years, sexual risky behaviours have led to resurgence of old affections (like syphilis) or to emergence of unknown diseases (like lymphogranuloma venereum) in our countries. This presentation tends to focus on clinical manifestation, diagnosis and treatment of different STD: HPV, Herpes Simplex Virus, Neisseria gonorrhoeae, Chlamydia trachomatis (in particularly lymphogranuloma venereum) and Treponema pallidum. PMID:20163035

  11. Sexually transmitted infections and adolescence.

    PubMed

    Ljubojević, Suzana; Lipozenčić, Jasna

    2010-01-01

    Sexually transmitted infections (STIs) remain a public health problem of major significance in most of the world. Adolescents make up about 20% of the world population, of whom 85% live in developing countries. They are at a greater risk of STIs because they frequently have unprotected intercourse, biologically may be more susceptible to infection, often are engaged in multiple monogamous relationships of limited duration, and face multiple obstacles in accessing confidential health care services. Young people who begin to have sexual intercourse in early or middle adolescence are more likely to develop an STI than those who postpone intercourse until later adolescence or adulthood. The most common STIs among adolescents are chlamydia, gonorrhea, human papillomavirus infection, and trichomoniasis. Unfortunately, lately the incidence of HIV/AIDS and syphilis among adolescents is growing. Comprehensive sex education programs in schools can increase STI knowledge and prevent risky sexual behaviors. Health care providers can promote STI prevention methods, including counseling about safe sex. PMID:21251451

  12. Vibration analyzer

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1990-01-01

    The invention relates to monitoring circuitry for the real time detection of vibrations of a predetermined frequency and which are greater than a predetermined magnitude. The circuitry produces an instability signal in response to such detection. The circuitry is particularly adapted for detecting instabilities in rocket thrusters, but may find application with other machines such as expensive rotating machinery, or turbines. The monitoring circuitry identifies when vibration signals are present having a predetermined frequency of a multi-frequency vibration signal which has an RMS energy level greater than a predetermined magnitude. It generates an instability signal only if such a vibration signal is identified. The circuitry includes a delay circuit which responds with an alarm signal only if the instability signal continues for a predetermined time period. When used with a rocket thruster, the alarm signal may be used to cut off the thruster if such thruster is being used in flight. If the circuitry is monitoring tests of the thruster, it generates signals to change the thruster operation, for example, from pulse mode to continuous firing to determine if the instability of the thruster is sustained once it is detected.

  13. Hand lotion poisoning

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002708.htm Hand lotion poisoning To use the sharing features on this page, please enable JavaScript. Hand lotion poisoning occurs when someone swallows hand lotion or ...

  14. Chapped hands (image)

    MedlinePlus

    Chapped hands can be sore and painful. Chapped hands may be soothed by the use of moisturizing lotions and the avoidance of excess exposure to water. If hands become badly chapped, hydrocortisone creams (available over the ...

  15. Hand splint - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100142.htm Hand splint - series—Indications To use the sharing features ... out of 4 Overview To begin making a hand dressing, place the injured hand around a cloth ...

  16. Calibration of sound and vibration sensors and vibration testing systems

    NASA Astrophysics Data System (ADS)

    Nicklich, Holger

    2004-08-01

    SPEKTRA is a manufacturer of high quality calibration systems for sound and vibration. Under license No DKD-K-27801, a calibration lab was established at SPEKTRA to provide a calibration service. The paper gives a summary of 4 years experience in the calibration of vibration Sensors, measuring systems and vibration test equipment in the industrial field. In practice calibration is often treated as an unpleasant job that is solved by handing out a “Calibration certificate of every part of the system” to the Quality Manager. The paper comes to the conclusion that calibration can help to minimize costs and risks if the customer has basic knowledge in international standards, the used test equipment and the special requirements for testing with this configuration. It is not enough to calibrate one sensor of a system in a standard range. The requirements for calibration should be defined individually for every testing system and application.

  17. Calibration of Sound and Vibration Sensors and Vibration Testing Systems

    NASA Astrophysics Data System (ADS)

    Nicklich, H.

    2004-08-01

    SPEKTRA is a manufacturer of high quality calibration systems for sound and vibration. Under license No DKD-K-27801, a calibration lab was established at SPEKTRA to provide a calibration service. The paper gives a summary of 4 years experience in the calibration of vibration Sensors, measuring systems and vibration test equipment in the industrial field. In practice calibration is often treated as an unpleasant job that is solved by handing out a "Calibration certificate of every part of the system" to the Quality Manager. The paper comes to the conclusion that calibration can help to minimize costs and risks if the customer has basic knowledge in international standards, the used test equipment and the special requirements for testing with this configuration. It is not enough to calibrate one sen- sor of a system in a standard range. The requirements for calibration should be defined individually for every testing system and application.

  18. Two-Stage Passive Vibration Isolator

    NASA Technical Reports Server (NTRS)

    Goullioud, Renaud; Gursel, Yekta; Neville, Timothy; Bronowicki, Allen J.; Platus, David; MacDonald, Rhonda

    2008-01-01

    The design and testing of a structural system were implemented to hold the optics of the planned Space Interferometry Mission (SIM) at positions and orientations characterized by vibrational translation and rotation errors of no more than a few nanometers or a few milliarcseconds, respectively. Much of the effort was devoted to a test bed for verifying the predicted behavior of a vibration- isolation structural subsystem working together with an active control system for positioning and orienting the SIM optics. There was considerable emphasis on the vibration-isolation subsystem, which was passive and comprised two stages. The main sources of vibration were six reaction wheels in an assembly denoted the "backpack." The first vibration-isolation stage consisted of hexapod isolator mounts - one for each reaction wheel - characterized by a natural vibration frequency of 10 Hz. The second stage was a set of three beams, disposed between the backpack and the structure that held the SIM optics, that were flexured such that they transmitted only bending loads, with a natural vibrational frequency and damping of about 5 Hz and 4 percent, respectively. Preliminary test results were presented and characterized as demonstrating the effectiveness of the two-stage vibration-isolation design.

  19. Force-limited vibration tests aplied to the FORTE` satellite

    SciTech Connect

    Stevens, R.R.; Butler, T.A.

    1996-02-01

    A force limited random vibration test was conducted on a small satellite called FORTE{prime}. This type of vibration test reduces the over testing that can occur in a conventional vibration test. Two vibration specifications were used in the test: The conventional base acceleration specification, and an interface force specification. The vibration level of the shaker was controlled such that neither the table acceleration nor the force transmitted to the test item exceeded its specification. The effect of limiting the shake table vibration to the force specification was to reduce (or ``notch``) the shaker acceleration near some of the satellite`s resonance frequencies. This paper describes the force limited test conducted for the FORTE{prime} satellite. The satellite and its dynamic properties are discussed, and the concepts of force limiting theory are summarized. The hardware and setup of the test are then described, and the results of the force limited vibration test are discussed.

  20. Good Vibrations

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A Small Business Innovation Research (SBIR) sponsorship from NASA's Dryden Flight Research Center, assisted MetroLaser, of Irvine, California, in the development of a self-aligned laser vibrometer system. VibroMet, capable of measuring surface vibrations in a variety of industries, provides information on the structural integrity and acoustical characteristics of manufactured products. This low-cost, easy-to-use sensor performs vibration measurement from distances of up to three meters without the need for adjustment. The laser beam is simply pointed at the target and the system then uses a compact laser diode to illuminate the surface and to subsequently analyze the reflected light. The motion of the surface results in a Doppler shift that is measured with very high precision. VibroMet is considered one of the many behind-the-scenes tools that can be relied on to assure the quality, reliability and safety of everything from airplane panels to disk brakes

  1. Wash Your Hands

    MedlinePlus

    ... do if you don't have soap and clean, running water? Washing hands with soap and water is the ... specific questions. More Information CDC's Handwashing Work Handwashing: Clean Hands Save Lives Hand Hygiene in Healthcare Settings Water-related Hygiene Hand Hygiene to Help Prevent Flu ...

  2. Infection after hand surgery.

    PubMed

    Eberlin, Kyle R; Ring, David

    2015-05-01

    Postoperative infections are uncommon after hand surgery. Infection can delay recovery and contribute to scarring and stiffness. Measures intended to reduce the risk of infection after hand surgery include hand washing, skin preparation, sterile technique, and prophylactic antibiotics. The role of prophylactic antibiotics for small, clean, elective hand surgery procedures lasting less than 2 hours is debated. PMID:25934209

  3. Transfusion-Transmitted Babesia microti.

    PubMed

    Fang, Deanna C; McCullough, Jeffrey

    2016-07-01

    Because testing of donors for Babesia microti has become available, it is important to determine the kinds of patients who should receive B microti-tested blood. We searched PubMed, AABB abstracts, and FDA Web site to identify all cases of transfusion-transmitted babesiosis (TTB). Cases were analyzed for underlying medical condition, age, presence of spleen, and reason for transfusion in relation to 5 classes of recipient outcome severity. Sixty-seven reports included 256 transfusion cases where donor tested positive for B microti, 165 of which resulted in TTB. Sixty recipients did not develop disease or become test positive, and test results were not known for 31 more. The 165 cases of TTB involved hematologic (19%), neonate (10%), cardiovascular (8%), and gastrointestinal (6%) patients. Thirty-two (19%) of the 165 infected patients died with death attributed to babesiosis in 25 of the cases. Nine (5%) were asymptomatic, 27 (16%) were symptomatic but had uncomplicated disease, and 16 (10%) had complicated disease. The severity of disease was mixed among many disease categories. Patients >65 years of age included the largest number of recipients (59/165, 36%) and deaths (11/32, 34%), although deaths occurred in other age groups as well. TTB cases were predominantly due to red cells (133 of 140 specified units), with red blood cell units processed in a variety of ways and at all storage duration. TTB with complicated babesiosis and/or death occurred in patients of all age groups and with a variety of underlying medical conditions. PMID:27260107

  4. Force reflecting hand controller for manipulator teleoperation

    NASA Technical Reports Server (NTRS)

    Bryfogle, Mark D.

    1991-01-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  5. Static hand gesture recognition from a video

    NASA Astrophysics Data System (ADS)

    Rokade, Rajeshree S.; Doye, Dharmpal

    2011-10-01

    A sign language (also signed language) is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning- "simultaneously combining hand shapes, orientation and movement of the hands". Sign languages commonly develop in deaf communities, which can include interpreters, friends and families of deaf people as well as people who are deaf or hard of hearing themselves. In this paper, we proposed a novel system for recognition of static hand gestures from a video, based on Kohonen neural network. We proposed algorithm to separate out key frames, which include correct gestures from a video sequence. We segment, hand images from complex and non uniform background. Features are extracted by applying Kohonen on key frames and recognition is done.

  6. Force reflecting hand controller for manipulator teleoperation

    NASA Astrophysics Data System (ADS)

    Bryfogle, Mark D.

    1991-12-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  7. Pediatric Hand Injuries.

    PubMed

    Sullivan, Matthew A; Cogan, Charles J; Adkinson, Joshua M

    2016-01-01

    Pediatric hand injuries are extremely common. Although many hand injuries are adequately managed in the emergency department, some may need evaluation and treatment by a pediatric hand surgeon to ensure a good functional outcome. This article discusses the diagnosis and management of the most common pediatric hand maladies: fingertip injuries/amputation, tendon injuries, and phalangeal and metacarpal fractures. The plastic surgery nurse should be familiar with hand injuries that require intervention to facilitate efficient management and optimal postoperative care. PMID:27606586

  8. Transmission Conditions of Vibration Stresses to Welding Specimens of Ultrasonic Plastic Welding using Various Two-Vibration-System Equipments

    NASA Astrophysics Data System (ADS)

    Tsujino, Jiromaru; Uchida, Takako; Ohkusa, Kunifumi; Adachi, Tatsuya; Ueoka, Tetsugi

    1998-05-01

    Ultrasonic plastic welding is applied for welding various thermoplastic materials and is widely used in various industrial fields. The two-vibration-system welding method and a high frequency equipment are effective in improving the welding characteristics. A high frequency 90 kHz system can weld plastic sheets under a 1/3 velocity amplitude as compared with that of a low 27 kHz system, but it is difficult to weld large specimens successfully because a high frequency vibration stress cannot be transmitted uniformly due to the stress relaxation effect by the small vibration displacement. To improve the direct welding characteristics, three types of two-vibration-system ultrasonic welding equipments using linear vibration loci of (1) 90 kHz and 27 kHz longitudinal vibration systems, (2) 90 kHz longitudinal and 20 kHz torsional vibration systems, and elliptical vibration loci of (3) 27 kHz complex vibration systems are studied. Transmission conditions of the vibration stresses are measured by pressure sensitive films (Prescale) which are inserted between the plastic sheets. It was shown that a high frequency vibration stress with a small displacement amplitude may be induced uniformly in the welding specimens by combining a low frequency vibration with large displacement amplitude. These welding systems are effectively used to join plastic sheets successfully.

  9. Moral Reasoning about Sexually Transmitted Diseases.

    ERIC Educational Resources Information Center

    Jadack, Rosemary A.; And Others

    1995-01-01

    Using hypothetical scenarios in which sexually transmitted diseases (STDs) can be transmitted, college freshmen and seniors were asked to explain why they believed the characters should or should nor engage in risky behaviors. Results indicated that seniors had a significantly higher stage of moral reasoning than the freshmen when responding to…

  10. Reductions in finger blood flow induced by 125-Hz vibration: effect of area of contact with vibration.

    PubMed

    Ye, Ying; Griffin, Michael J

    2013-04-01

    To investigate whether the Pacinian channel is involved in vibration-induced reductions of finger blood flow (FBF), vibrotactile thresholds and vasoconstriction have been studied with 125-Hz vibration and two contact areas: 3- or 6-mm-diameter vibrating probes with 2-mm gaps to fixed surrounds. Fifteen subjects provided thresholds for perceiving vibration at the thenar eminence of the right hand with both contact areas. With both contact areas, FBF was then measured in the middle fingers of both hands during five successive 5-min periods: (i) no force and no vibration, (ii) force and no vibration, (iii) force with vibration 15 dB above threshold, (iv) force and no vibration, and (v) no force and no vibration. Thresholds were in the ranges of 0.16-0.66 ms(-2) r.m.s. (6-mm probe) and 0.32-1.62 ms(-2) r.m.s. (3-mm probe). With the magnitude of vibration 15 dB above each individual's threshold with the 3-mm probe, the median reduction in FBF with the 6-mm probe (to 70 and 77 % of pre-exposure FBF on the exposed right hand and the unexposed left hand, respectively) was greater than with the 3-mm probe (79 and 85 %). There were similar reductions in FBF when vibration was presented by the two contactors at the same sensation level (i.e. 15 dB above threshold with each probe). The findings are consistent with reductions in FBF arising from excitation of the Pacinian channel: increasing the area excited by vibration increases Pacinian activation and provokes stronger perception of vibration and greater vasoconstriction. PMID:23064872

  11. Violin bow vibrations.

    PubMed

    Gough, Colin E

    2012-05-01

    The modal frequencies and bending mode shapes of a freely supported tapered violin bow are investigated by finite element analysis and direct measurement, with and without tensioned bow hair. Such computations are used with analytic models to model the admittance presented to the stretched bow hairs at the ends of the bow and to the string at the point of contact with the bow. Finite element computations are also used to demonstrate the influence of the lowest stick mode vibrations on the low frequency bouncing modes, when the hand-held bow is pressed against the string. The possible influence of the dynamic stick modes on the sound of the bowed instrument is briefly discussed. PMID:22559386

  12. Find a Hand Surgeon

    MedlinePlus

    ... Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring ... Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring ...

  13. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of hand fractures Your fracture may be in one of ...

  14. Hands-Only CPR

    MedlinePlus

    ... Instructors ECC Educational Conferences Programs CPR In Schools Hands-Only CPR Community CPR Tracker AED Implementation OSHA and AHA Alliance Be The Beat Hands-Only CPR Program Recursos para hispanohablantes en EE ...

  15. Hand and Finger Exercises

    MedlinePlus

    Hand and Finger Exercises  Place your palm flat on a table. Raise and lower your fingers one ... times for ____ seconds.  Pick up objects with your hand. Start out with larger objects. Repeat ____ times for ____ ...

  16. Hand Injuries and Disorders

    MedlinePlus

    ... for a living, you are always using your hands. When there is something wrong with them, you ... not be able to do your regular activities. Hand problems include Carpal tunnel syndrome - compression of a ...

  17. Active control of vibration transmission through struts

    NASA Astrophysics Data System (ADS)

    Pelinescu, Ion; Balachandran, Balakumar

    1998-07-01

    In this work, analytical investigations into active control of longitudinal and flexural vibrations transmitted through a cylindrical strut are conducted. A mechanics based model for a strut fitted with a piezoelectric actuator is developed. For harmonic disturbances, a linear dynamic formulation describing the motion of the actuator is integrated with the formulation describing wave transmission through the strut, and the resulting system is studied in the frequency domain. Open-loop studies are conducted with the aid of numerical simulations, and the potential of active control schemes to attenuate the transmitted vibrations over the frequency range of 10 Hz to 6000 Hz is examined. The relevance of the current work to control of helicopter cabin interior noise is also discussed.

  18. Hand x-ray

    MedlinePlus

    X-ray - hand ... A hand x-ray is taken in a hospital radiology department or your health care provider's office by an ... technician. You will be asked to place your hand on the x-ray table, and keep it ...

  19. Method and apparatus for transmitting data

    NASA Technical Reports Server (NTRS)

    Schroeder, George L. (Inventor); Couch, Francis O. (Inventor); Saenguraiporn, Chamna (Inventor)

    1990-01-01

    A method and apparatus for transmitting a byte-organized serial data stream from a transmitting station to a receiving station that may employ byte boundaries different than the transmitting station. The technique includes sending N different data streams from the remote terminal, where N is the number of different framing alignments that may be imposed on the unframed data stream by the network. The different data streams are chosen so that one will be framed by the network as the intended data stream regardless of which framing alignment is actually imposed.

  20. Development of adaptive helicopter seat systems for aircrew vibration mitigation

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Wickramasinghe, Viresh; Zimcik, David G.

    2008-03-01

    Helicopter aircrews are exposed to high levels of whole body vibration during flight. This paper presents the results of an investigation of adaptive seat mount approaches to reduce helicopter aircrew whole body vibration levels. A flight test was conducted on a four-blade helicopter and showed that the currently used passive seat systems were not able to provide satisfactory protection to the helicopter aircrew in both front-back and vertical directions. Long-term exposure to the measured whole body vibration environment may cause occupational health issues such as spine and neck strain injuries for aircrew. In order to address this issue, a novel adaptive seat mount concept was developed to mitigate the vibration levels transmitted to the aircrew body. For proof-of-concept demonstration, a miniature modal shaker was properly aligned between the cabin floor and the seat frame to provide adaptive actuation authority. Adaptive control laws were developed to reduce the vibration transmitted to the aircrew body, especially the helmet location in order to minimize neck and spine injuries. Closed-loop control test have been conducted on a full-scale helicopter seat with a mannequin configuration and a large mechanical shaker was used to provide representative helicopter vibration profiles to the seat frame. Significant vibration reductions to the vertical and front-back vibration modes have been achieved simultaneously, which verified the technical readiness of the adaptive mount approach for full-scale flight test on the vehicle.

  1. Removable hand hold

    NASA Technical Reports Server (NTRS)

    Corrigan, Robert D. (Inventor); Hauer, Robert L. (Inventor)

    1992-01-01

    A hand hold utilizes joining mechanisms which comprises two different mounting brackets that are permanently fastened to a supporting structure. A slide plate is disposed at one end of the hand rail or hand hold which mates with one of the mounting brackets. A securing member is disposed at the opposite end of the hand rail/hand hold which connects with the other mounting bracket by means of a locking device. The slide plate has a central tapered tongue with two matching slots disposed on each side thereof.

  2. Turbojet blade vibration data acquisition design and feasibility testing

    NASA Technical Reports Server (NTRS)

    Frarey, J. L.; Petersen, N. J.; Hess, D. A.

    1978-01-01

    A turbojet blade vibration data acquisition system was designed to allow the measurement of blade vibration. The data acquisition system utilizing 96 microprocessors to gather data from optical probes, store, sort and transmit to the central computer is described. Areas of high technical risk were identified and a two-microprocessor system was breadboarded and tested to investigate these areas. Results show that the system was feasible and that low technical risk would be involved in proceeding with the complete system fabrication.

  3. Hand held phase-shifting diffraction moire interferometer

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1994-01-01

    An interferometer in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case.

  4. Hand held phase-shifting diffraction Moire interferometer

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1994-09-20

    An interferometer is described in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case. 4 figs.

  5. Sexually Transmitted Diseases Surveillance, 2012: Chlamydia

    MedlinePlus

    ... on Facebook Archive Data & Statistics Sexually Transmitted Diseases Chlamydia Recommend on Facebook Tweet Share Compartir This web ... screened in a variety of settings are monitored. Chlamydia—United States In 2012, a total of 1, ...

  6. Sexually Transmitted Diseases Surveillance, 2012: Syphilis

    MedlinePlus

    ... on Facebook Archive Data & Statistics Sexually Transmitted Diseases Syphilis Recommend on Facebook Tweet Share Compartir This web ... MSM accounted for 75% of P&S syphilis cases. Syphilis—All Stages (P&S, Early Latent, Late, Late Latent, ...

  7. Sexually Transmitted Diseases: Teens at Risk.

    ERIC Educational Resources Information Center

    Mascola, Laurene

    1987-01-01

    Parents of preteens need to be aware of the rapidly increasing incidence of sexually transmitted diseases among teenagers and to begin talking to their preteens to help prevent or modify risky sexual experimentation during middle adolescence. (MT)

  8. Clinical update in sexually transmitted diseases-2014.

    PubMed

    Fanfair, Robyn Neblett; Workowski, Kimberly A

    2014-02-01

    Sexually transmitted diseases (STDs) and their associated syndromes are extremely common in clinical practice. Early diagnosis, appropriate treatment, and partner management are important to ensure sexual, physical, and reproductive health in our patients. PMID:24493491

  9. Optical fiber sensors using vibration wires

    NASA Astrophysics Data System (ADS)

    Feng, Maria Q.; Suzuki, Hideyo

    1994-09-01

    Experimental research of new optical fiber sensors for monitoring civil infrastructure systems is presented. The proposed optical sensors employ a vibrating wire shoe tension can be modulated by external force, strain, or vibration and is translated into the change in the wire vibration frequency. The wire vibration frequency is detected by light sent to and reflected from the wire through an optical fiber cable. Compared to other existing optical fiber sensors which tend to suffer from the lack of reliability and robustness, the proposed sensors have two significant advantages: one is that the sensing head is a vibrating wire (rather than an optical fiber), which can sense a specific physical quantity without interference from miscellaneous effects; the other is that the wire vibration is a well understood physical phenomenon. In fact, with a high level of reliability, its frequency is optically measured and transmitted to recording and other devices through the optical fiber without attenuation or distortion. These advantages make the sensor system simple, reliable and robust, and hence more readily deployable in civil infrastructure applications.

  10. Novel transmit protection scheme for ultrasound systems.

    PubMed

    Fuller, Michael I; Blalock, Travis N; Hossack, John A; Walker, William F

    2007-01-01

    The problem of protecting or isolating extremely sensitive receive circuitry from high-voltage transmit circuitry is commonly addressed through the use of diode bridges, transformers, or high-voltage switches, which prove to be prohibitively expensive, bulky, and power consuming for use in portable, low-cost, battery-powered systems. These approaches also compound the interconnect difficulties associated with two-dimensional (2-D) transducer arrays. In this paper we present a novel transmit protection scheme that allows compact MOSFET shunting devices to be brought on-chip within each receive channel implemented in a standard CMOS integrated circuit process. During transmit, the high voltage transmit pulse is driven onto the common connection of the transducer array and the on-chip MOSFET devices shunt the current to ground. During receive, these devices are turned off, the common connection of the transducer array is shunted to ground, and the received echo can be detected as usual. The transmit protection scheme was experimentally shown to shunt a 16 mA peak current resulting from the equivalent of a 100-V, 25-ns-risetime transmit pulse through a 4 pF transducer element. The scheme was also incorporated into a prototype 1024-channel, low-cost, ultrasound system successfully used to form pulse echo images. PMID:17225802

  11. Noncontact Electromagnetic Vibration Source

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Fulton, James P.; Wincheski, Buzz A.

    1994-01-01

    Metal aircraft skins scanned rapidly in vibration tests. Relatively simple combination of permanent magnets and electromagnet serves as noncontact vibration source for nondestructive testing of metal aircraft skins. In test, source excites vibrations, and vibration waveforms measured, then analyzed for changes in resonances signifying cracks and other flaws.

  12. Effect of the air hammer on the hands of stonecutters. The limestone quarries of Bedford, Indiana, revisited.

    PubMed

    Taylor, W; Wasserman, D; Behrens, V; Reynolds, D; Samueloff, S

    1984-08-01

    In the limestone quarries of Indiana, USA, pneumatic percussive hammers replaced the mallet and hammer around 1900. By 1917 the air hammer was being used exclusively for periods of eight to ten hours a shift. In 1918 Alice Hamilton investigated an unusual "disease" in these stonecutters of Bedford, Indiana, who complained of "attacks of numbness and blanching of the fingers coming on suddenly under the influence of cold and then disappearing." The prevalence of vibration induced white finger (VWF) found in this population of 38 stonecutters was 89%, with decreased light touch, pain, and temperature appreciation in advanced cases. In 1978 a VWF research team revisited these limestone quarries. During the 60 year interval the stonecutting industry had contracted from 4000 workers in 40 quarries in 1918 to 3-400 in 10 quarries in 1978, with only 50 employees remaining in the Bedford area. In a population of 30 stonecutters the prevalence of VWF in 1978 was 80%, with similar sensory loss in light touch, pain, and temperature appreciation. Between 1918 and 1978 no change had taken place in the design of the air hammers used for stonecutting. Vibration levels of 4859 metres/s2 on the chisel, and 2010 metres/s2 on the barrel were measured over a frequency range 6.3 to 1000 Hz. The fundamental frequency was 75 Hz. These measured vibration levels are outside the ISO/DIS/5349 (1979) recommended limits for human exposure to vibration transmitted to the hand. The VWF data presented in this paper, and those originally reported by Hamilton in 1918, call for an immediate redesign of stonecutting pneumatic hammers in order to remove one cause of Raynaud's phenomenon of occupational origin. PMID:6378250

  13. Vibrational ratchets

    NASA Astrophysics Data System (ADS)

    Borromeo, M.; Marchesoni, F.

    2006-01-01

    Transport in one-dimensional symmetric devices can be activated by the combination of thermal noise and a biharmonic drive. For the study case of an overdamped Brownian particle diffusing on a periodic one-dimensional substrate, we distinguish two apparently different biharmonic regimes: (i) Harmonic mixing, where the two drive frequencies are commensurate and of the order of some intrinsic relaxation rate. Earlier predictions based on perturbation expansions seem inadequate to interpret our simulation results; (ii) Vibrational mixing, where one harmonic drive component is characterized by high frequency but finite amplitude-to-frequency ratio. Its effect on the device response to either a static or a low-frequency additional input signal is accurately reproduced by rescaling each spatial Fourier component of the substrate potential, separately. Contrary to common wisdom, based on the linear response theory, we show that extremely high-frequency modulations can indeed influence the response of slowly (or dc) operated devices, with potential applications in sensor technology and cellular physiology. Finally, the mixing of two high-frequency beating signal is also investigated both numerically and analytically.

  14. Flow-induced vibration

    SciTech Connect

    Blevins, R.D.

    1990-01-01

    This book reports on dimensional analysis; ideal fluid models; vortex-induced vibration; galloping and flutter; instability of tube and cylinder arrays; vibrations induced by oscillating flow; vibration induced by turbulence and sound; damping of structures; sound induced by vortex shedding; vibrations of a pipe containing a fluid flow; indices. It covers the analysis of the vibrations of structures exposed to fluid flows; explores applications for offshore platforms and piping; wind-induced vibration of buildings, bridges, and towers; and acoustic and mechanical vibration of heat exchangers, power lines, and process ducting.

  15. Center of percussion of hand-held implements

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2004-05-01

    The center of percussion is commonly regarded as a sweet spot when referring to a baseball bat or a tennis racquet because it is assumed that there will be no sudden motion of the handle with respect to the hand if the corresponding axis of rotation passes through the hand. A problem with this interpretation is that the hand extends over a finite length of the handle and exerts an opposing reaction force on the handle. The hand also changes the total mass and moment of inertia of the system, while the arm restricts free motion of the hand. Experimental results are presented showing that the axis of rotation passes through the hand or the wrist for all the usual impact points on a hand-held implement. As a result, the impact point that feels best is usually the node of the fundamental vibration mode, not the center of percussion.

  16. Tropical diabetic hand syndrome.

    PubMed

    Tiwari, Sangeeta; Chauhan, Ashutosh; Sethi, N T

    2008-10-01

    Tropical diabetic hand syndrome (TDHS) is a terminology used to describe a specific complication affecting patients with diabetes mellitus in the tropics. The syndrome encompasses a localized cellulitis with variable swelling and ulceration of the hands to progressive, fulminant hand sepsis, potentially fatal. Since this syndrome is less recognized it is often under-reported. Authors present two cases of TDHS and emphasize on aggressive glycemic control and surgical therapy to prevent potential crippling or fatal complications. PMID:20165601

  17. Hand Hygiene: An Update.

    PubMed

    Bolon, Maureen K

    2016-09-01

    The medical field has long recognized the importance of hand hygiene in preventing health care-associated infections, yet studies indicate that this important task is performed only 40% of the time. Health care workers cite several barriers to optimal performance of hand hygiene, but the time required to perform this task is foremost among them. Introduction of alcohol-based hand rubs, bundled interventions, and incorporation of technologies designed to monitor and promote hand hygiene all represent promising advances in this field. PMID:27515139

  18. Coordination of hand shape.

    PubMed

    Pesyna, Colin; Pundi, Krishna; Flanders, Martha

    2011-03-01

    The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness. PMID:21389230

  19. Dextrous robot hands

    NASA Technical Reports Server (NTRS)

    Venkataraman, Subramanian T. (Editor); Iberall, Thea (Editor)

    1990-01-01

    Recent studies of human hand function and their implications for the design of robot hands are discussed in reviews and reports. Topics addressed include human grasp choice and robotic grasp analysis, opposition space and human prehension, coordination in normal and prosthetic reaching, and intelligent exploration by the human hand. Consideration is given to a task-oriented dextrous manipulation architecture, the control architecture for the Belgrade/USC hand, the analysis of multifingered grasping and manipulation, and tactile sensing for shape interpretation. Diagrams, graphs, and photographs are provided.

  20. Wave Propagation in Exponentially Varying Cross-Section Rods and Vibration Analysis

    SciTech Connect

    Nikkhah-Bahrami, Mansour; Loghmani, Masih; Pooyanfar, Mostafa

    2008-09-01

    In this paper vibration as propagating waves is used to calculate frequencies of exponentially varying cross-section rods with various boundary conditions. From wave standpoint, vibrations propagate, reflect and transmit in structures. The propagation and reflection matrices are combined to provide a concise and systematic approach to free longitudinal vibration analysis of exponentially varying cross-section rods. The results are compared with another method.

  1. A Helping Hand.

    ERIC Educational Resources Information Center

    Renner, Jason M.

    2000-01-01

    Discusses how designing a hand washing-friendly environment can help to reduce the spread of germs in school restrooms. Use of electronic faucets, surface risk management, traffic flow, and user- friendly hand washing systems that are convenient and maximally hygienic are examined. (GR)

  2. On the control of vibrations using synchrophasing

    NASA Astrophysics Data System (ADS)

    Dench, M. R.; Brennan, M. J.; Ferguson, N. S.

    2013-09-01

    This paper describes the application of a technique, known as synchrophasing, to the control of machinery vibration. It is applicable to machinery installations, in which several synchronous machines, such as those driven by electrical motors, are fitted to an isolated common structure known as a machinery raft. To reduce the vibration transmitted to the host structure to which the machinery raft is attached, the phase of the electrical supply to the motors is adjusted so that the net transmitted force to the host structure is minimised. It is shown that while this is relatively simple for an installation consisting of two machines, it is more complicated for installations in which there are more than two machines, because of the interaction between the forces generated by each machine. The development of a synchrophasing scheme, which has been applied to propeller aircraft, and is known as Propeller Signature Theory (PST) is discussed. It is shown both theoretically and experimentally, that this is an efficient way of controlling the phase of multiple machines. It is also shown that synchrophasing is a worthwhile vibration control technique, which has the potential to suppress vibration transmitted to the host structure by up to 20 dB at certain frequencies. Although the principle of synchronisation has been demonstrated on a one-dimensional structure, it is believed that this captures the key features of the approach. However, it should be realised that the mode-shapes of a machinery raft may be more complex than that of a one-dimensional structure and this may need to be taken into account in a real application.

  3. Management of sexually transmitted disease by surgeons.

    PubMed Central

    Hunt, L. M.; Nash, J. R.; Dilke-Wing, G. M.

    1998-01-01

    The management of 63 patients diagnosed by surgeons as having sexually transmitted disease (STD) was audited. A diagnosis of STD was made in 51 (81%) of patients without taking a sexual history. Only 2 (3%) patients were referred to genitourinary medicine (GUM). Appropriate microbiological specimens were obtained from only two of 52 (4%) patients diagnosed with either pelvic inflammatory disease (PID) or epididymo-orchitis. Reliance was placed on inappropriate specimens in 22 (42%). There was widespread use of inappropriate antibiotics. The management of sexually transmitted disease by surgeons was very poor. These patients should all be referred to genito-urinary medicine. Images Figure 1 PMID:9849339

  4. Updating the management of sexually transmitted infections

    PubMed Central

    Ooi, Catriona; Lewis, David

    2015-01-01

    SUMMARY The control of sexually transmitted infections relies on case-finding and treatment of sexual contacts to prevent further transmission. Screening for infections should be tailored to the demographic and sexual risk of the individual. For most sexually transmitted infections, screening is performed on self-collected, non-invasive samples using highly sensitive molecular assays. These are quick and inexpensive. Shorter courses of antivirals for genital herpes are now recommended. New chemoprophylactic strategies for preventing HIV transmission have emerged, including treatment to prevent transmission and the use of antiretrovirals for pre-exposure prophylaxis. PMID:26843713

  5. Sexually transmitted infections in polygamous mating systems

    PubMed Central

    Ashby, Ben; Gupta, Sunetra

    2013-01-01

    Sexually transmitted infections (STIs) are often associated with chronic diseases and can have severe impacts on host reproductive success. For airborne or socially transmitted pathogens, patterns of contact by which the infection spreads tend to be dispersed and each contact may be of very short duration. By contrast, the transmission pathways for STIs are usually characterized by repeated contacts with a small subset of the population. Here we review how heterogeneity in sexual contact patterns can influence epidemiological dynamics, and present a simple model of polygyny/polyandry to illustrate the impact of biased mating systems on disease incidence and pathogen virulence. PMID:23339239

  6. Updating the management of sexually transmitted infections.

    PubMed

    Ooi, Catriona; Lewis, David

    2015-12-01

    The control of sexually transmitted infections relies on case-finding and treatment of sexual contacts to prevent further transmission. Screening for infections should be tailored to the demographic and sexual risk of the individual. For most sexually transmitted infections, screening is performed on self-collected, non-invasive samples using highly sensitive molecular assays. These are quick and inexpensive. Shorter courses of antivirals for genital herpes are now recommended. New chemoprophylactic strategies for preventing HIV transmission have emerged, including treatment to prevent transmission and the use of antiretrovirals for pre-exposure prophylaxis. PMID:26843713

  7. Sexually transmitted diseases in Sabah and Sarawak.

    PubMed Central

    Catterall, R D

    1981-01-01

    Despite being part of one of the few remaining primitive areas of the world, both Sabah and Sarawak are provided with adequate, though simple, urban and rural general medical services. At present no reliable data on the incidence of sexually transmitted diseases in these areas have been collected and no organised treatment services are available. Gonorrhoea appears to be the commonest notifiable infectious disease in Sarawak, and beta-lactamase-producing strains have been isolated. Because of the rapidly expanding economy and the encouragement of the tourist trade, sexually transmitted disease is likely to prove an increasing problem, for which a specialised service for diagnosis and treatment is badly needed. PMID:6895709

  8. [The hand and rheumatism].

    PubMed

    Lioté, F; Chicheportiche, V

    1997-01-01

    The hand is a major site of musculoskeletal disorders. Clinical features to be studied include the patient's age and sex, pain, stiffness, range of motion of the various joints of the wrists and hands, soft tissue swelling (particularly tendons sheaths), bone excrescences, skin changes. Radiological abnormalities in the hands, if any, may confirm the clinical diagnosis. The main features of rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, erosive degenerative changes, Südeck syndrome, calcium pyrophosphate dihydrate deposition disease, etc., are reviewed. PMID:9810076

  9. Facial and Hand Allotransplantation

    PubMed Central

    Pomahac, Bohdan; Gobble, Ryan M.; Schneeberger, Stefan

    2014-01-01

    Vascularized composite allotransplantation (VCA) is a novel therapeutic option for treatment of patients suffering from limb loss or severe facial disfigurement. To date, 72 hand and 19 facial transplantations have been performed worldwide. VCA in hand and facial transplantation is a complex procedure requiring a multidisciplinary team approach and extensive surgical planning. Despite good functional outcome, courses after hand and facial transplantation have been complicated by skin rejection. Long-term immunosuppression remains a necessity in VCA for allograft survival. To widen the scope of these quality-of-life-improving procedures, minimization of immunosuppression to limit risks and side effects is needed. PMID:24478387

  10. Contamination of healthcare workers' hands with bacterial spores.

    PubMed

    Sasahara, Teppei; Ae, Ryusuke; Watanabe, Michiyo; Kimura, Yumiko; Yonekawa, Chikara; Hayashi, Shunji; Morisawa, Yuji

    2016-08-01

    Clostridium species and Bacillus spp. are spore-forming bacteria that cause hospital infections. The spores from these bacteria are transmitted from patient to patient via healthcare workers' hands. Although alcohol-based hand rubbing is an important hand hygiene practice, it is ineffective against bacterial spores. Therefore, healthcare workers should wash their hands with soap when they are contaminated with spores. However, the extent of health care worker hand contamination remains unclear. The aim of this study is to determine the level of bacterial spore contamination on healthcare workers' hands. The hands of 71 healthcare workers were evaluated for bacterial spore contamination. Spores attached to subject's hands were quantitatively examined after 9 working hours. The relationship between bacterial spore contamination and hand hygiene behaviors was also analyzed. Bacterial spores were detected on the hands of 54 subjects (76.1%). The mean number of spores detected was 468.3 CFU/hand (maximum: 3300 CFU/hand). Thirty-seven (52.1%) and 36 (50.7%) subjects were contaminated with Bacillus subtilis and Bacillus cereus, respectively. Nineteen subjects (26.8%) were contaminated with both Bacillus species. Clostridium difficile was detected on only one subject's hands. There was a significant negative correlation between the hand contamination level and the frequency of handwashing (r = -0.44, P < 0.01) and a significant positive correlation between the hand contamination level and the elapsed time since last handwashing (r = 0.34, P < 0.01). Healthcare workers' hands may be frequently contaminated with bacterial spores due to insufficient handwashing during daily patient care. PMID:27236515

  11. Educator's Guide to Sexually Transmitted Diseases.

    ERIC Educational Resources Information Center

    Texas State Dept. of Health, Austin.

    This document contains an educational resource guide designed to help educators provide relevant education about sexually transmitted diseases (STDs) to secondary school students in compliance with the Texas State Board of Education Rules for Curriculum. The guide, taking a pragmatic approach that emphasizes a prevention/intervention strategy,…

  12. Inductive Reasoning about Causally Transmitted Properties

    ERIC Educational Resources Information Center

    Shafto, Patrick; Kemp, Charles; Bonawitz, Elizabeth Baraff; Coley, John D.; Tenenbaum, Joshua B.

    2008-01-01

    Different intuitive theories constrain and guide inferences in different contexts. Formalizing simple intuitive theories as probabilistic processes operating over structured representations, we present a new computational model of category-based induction about causally transmitted properties. A first experiment demonstrates undergraduates'…

  13. Sexually Transmitted Diseases: A Selective, Annotated Bibliography.

    ERIC Educational Resources Information Center

    Planned Parenthood Federation of America, Inc., New York, NY. Education Dept.

    This document contains a reference sheet and an annotated bibliography concerned with sexually transmitted diseases (STD). The reference sheet provides a brief, accurate overview of STDs which includes both statistical and background information. The bibliography contains 83 entries, listed alphabetically, that deal with STDs. Books and articles…

  14. Transmitting rotary motion at an angle

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T.

    1979-01-01

    Transmission consisting of corrugated metal tube that can bend along its axis can transmit torques in range of 100 to 1000 pound-inches at corner angles as great as 180 deg. Possible uses include submerged mechanisms and food processing machinery where sealed drive line without contaminating lubricants is required.

  15. Whitefly-transmitted viruses in cucurbits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three whitefly-transmitted virsues have recently been reported infecting various cucurbit crops, including squash and watermelon, in Florida. In September 2008, Cucurbit yellow stunting disorder virus and Squash vein yellowing virus were found infection cucurbits in west-central Florida....

  16. Fluid power-transmitting gas bearing

    NASA Technical Reports Server (NTRS)

    Collins, D.; De Furia, R.; Ezekiel, F.; Yang, P.

    1968-01-01

    Fluid power-transmitting gas bearing was designed that is essentially frictionless, stable, and highly efficient. The two basic components of this design are the base assembly and the upper plate. System could be a fluidic control system, a momentum exchange or reaction jet device.

  17. Survey of Research on Sexually Transmitted Diseases.

    ERIC Educational Resources Information Center

    Centers for Disease Control (DHHS/PHS), Atlanta, GA.

    This survey covers periodical literature published in the field of research on sexually transmitted diseases during 1985. The articles cover the following diseases: (1) genital chlamydial infection; (2) gonorrhea; (3) genital herpes infection; (4) human papillomavirus infection; (5) acquired immunodeficiency syndrome (AIDS); (6) genital…

  18. Versatile impact hand tool

    NASA Technical Reports Server (NTRS)

    Hodil, E. R.

    1968-01-01

    Improved cartridge-actuated impact hand tool includes a common power head and four attachments to punch holes, drive forced entry fasteners, hammer, and shear. The attachments are self-contained and easily fitted to the power head assembly.

  19. Arthritis of the Hand

    MedlinePlus

    ... of hand and wrist arthritis. (Note: The U.S. Food and Drug Administration does not test dietary supplements. These compounds may cause negative interactions with other medications. Always consult your doctor before taking dietary supplements.) ...

  20. Effects of Muscle Vibration on Multi-finger Interaction and Coordination

    PubMed Central

    Arpinar-Avsar, Pinar; Park, Jaebum; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    The purpose of this study was to investigate the effects of changes in the proprioceptive signals induced by muscle vibration on multi-finger interaction and coordination. We hypothesized that unintended force production by non-instructed fingers (enslaving) would increase with muscle vibration while synergy indices during steady-state force production would drop. The framework of the uncontrolled manifold hypothesis was used to quantify indices of multi-finger synergies stabilizing total force during steady-state force production and anticipatory changes in these indices (anticipatory synergy adjustments, ASAs) in preparation to a quick force pulse production with and without hand muscle vibration at 80 Hz. The dominant hands of twelve healthy right-handed subjects were tested under three conditions: no vibration, vibration of the palmar surface of the hand, and vibration of the forearm applied over the flexor muscles. There were no significant effects of vibration on maximal voluntary force. The magnitude of enslaving was larger during vibration of the hand compared to the other two conditions. During steady-state force production, strong synergies stabilizing total force were seen in all three conditions; however, indices of force-stabilizing synergies were lower during vibration of the hand. Prior to the force pulse initiation, the synergy index started to drop earlier and over a larger magnitude without vibration compared to either vibration condition. Effects of vibration on enslaving and synergy index may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools innervating the extrinsic flexor compartments. We conclude that multi-finger synergies are not based on signals from muscle receptors. The smaller synergy indices and ASAs may reflect supraspinal effects of the vibration-induced afferent activity, in particular its interactions with trans-thalamic loops. PMID:23736524

  1. Smart Hand For Manipulators

    NASA Astrophysics Data System (ADS)

    Fiorini, Paolo

    1987-10-01

    Sensor based, computer controlled end effectors for mechanical arms are receiving more and more attention in the robotics industry, because commonly available grippers are only adequate for simple pick and place tasks. This paper describes the current status of the research at JPL on a smart hand for a Puma 560 robot arm. The hand is a self contained, autonomous system, capable of executing high level commands from a supervisory computer. The mechanism consists of parallel fingers, powered by a DC motor, and controlled by a microprocessor embedded in the hand housing. Special sensors are integrated in the hand for measuring the grasp force of the fingers, and for measuring forces and torques applied between the arm and the surrounding environment. Fingers can be exercised under position, velocity and force control modes. The single-chip microcomputer in the hand executes the tasks of communication, data acquisition and sensor based motor control, with a sample cycle of 2 ms and a transmission rate of 9600 baud. The smart hand described in this paper represents a new development in the area of end effector design because of its multi-functionality and autonomy. It will also be a versatile test bed for experimenting with advanced control schemes for dexterous manipulation.

  2. Vibrational structure of DNA

    NASA Astrophysics Data System (ADS)

    Gómez C, S.; Rey-González, R. R.

    2003-10-01

    DNA has been object of more extensive research in last years. Human genome may be the main work. On the other hand, DNA has been used as physical system in opposite to its biological character. Examples of this are electronic, thermally and Ramman spectroscopy studies, in others. However, some DNA physical features are unclear, they deserve more work in a effort to understand them. In this work we are interesting on the vibrational properties of DNA. We model it as a lineal chain constituted by three different mass. We use two different constant forces into the Dynamical Matrix formalism. Two masses represent the real mass of DNA bases plus the glucose mass and the third represents the phosphate mass. In this model, DNA unit cell is composed by four masses The dispersion relation shows one acoustical and three optical branches. Also, there is a wide gap between the first and second optical branches. These features are confirmed by the density of states. Also we consider disorder effects in the proposal to do a more realistic model. In this case our results suggest a behavior as diatomic chain where the central and wide gap is preserved.

  3. Fingertip contact suppresses the destabilizing influence of leg muscle vibration

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Rabin, E.; DiZio, P.

    2000-01-01

    Touch of the hand with a stationary surface at nonmechanically supportive force levels (<1 N) greatly attenuates postural sway during quiet stance. We predicted such haptic contact would also suppress the postural destabilization caused by vibrating the right peroneus brevis and longus muscles of subjects standing heel-to-toe with eyes closed. In experiment 1, ten subjects were tested under four conditions: no-vibration, no-touch; no-vibration, touch; vibration, no-touch; and vibration, touch. A hand-held physiotherapy vibrator (120 Hz) was applied approximately 5 cm above the malleolous to stimulate the peroneus longus and brevis tendons. Touch conditions involved contact of the right index finger with a laterally positioned surface (<1 N of force) at waist height. Vibration in the absence of finger contact greatly increased the mean sway amplitude of the center of pressure and of the head relative to the no-vibration, no-touch control condition (P < 0.001). The touch, no-vibration and touch-vibration conditions were not significantly different (P > 0.05) from each other and both had significantly less mean sway amplitude of head and of center of pressure than the other conditions (P < 0.01). In experiment 2, eight subjects stood heel-to-toe under touch and no-touch conditions involving 40-s duration trials of peroneus tendon vibration at different duty cycles: 1-, 2-, 3-, and 4-s ON and OFF periods. The vibrator was attached to the subject's leg and remotely activated. In the no-touch conditions, subjects showed periodic postural disruptions contingent on the duty cycle and mirror image rebounds with the offset of vibration. In the touch conditions, subjects were much less disrupted and showed compensations occurring within 500 ms of vibration onset and mirror image rebounds with vibration offset. Subjects were able to suppress almost completely the destabilizing influence of the vibration in the 3- and 4-s duty cycle trials. These experiments show that haptic

  4. Photovoltaic device having light transmitting electrically conductive stacked films

    DOEpatents

    Weber, Michael F.; Tran, Nang T.; Jeffrey, Frank R.; Gilbert, James R.; Aspen, Frank E.

    1990-07-10

    A light transmitting electrically conductive stacked film, useful as a light transmitting electrode, including a first light transmitting electrically conductive layer, having a first optical thickness, a second light transmitting layer, having a second optical thickness different from the optical thickness of the first layer, and an electrically conductive metallic layer interposed between and in initimate contact with the first and second layers.

  5. 47 CFR 95.135 - Maximum authorized transmitting power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maximum authorized transmitting power. 95.135... transmitting power. (a) No station may transmit with more than 50 watts output power. (b) (c) A small control station at a point north of Line A or east of Line C must transmit with no more than 5 watts ERP. (d)...

  6. 47 CFR 95.135 - Maximum authorized transmitting power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... transmitting power. (a) No station may transmit with more than 50 watts output power. (b) (c) A small control station at a point north of Line A or east of Line C must transmit with no more than 5 watts ERP. (d) A... 47 Telecommunication 5 2011-10-01 2011-10-01 false Maximum authorized transmitting power....

  7. Remote vibration monitoring system using wireless internet data transfer

    NASA Astrophysics Data System (ADS)

    Lemke, John

    2000-06-01

    Vibrations from construction activities can affect infrastructure projects in several ways. Within the general vicinity of a construction site, vibrations can result in damage to existing structures, disturbance to people, damage to sensitive machinery, and degraded performance of precision instrumentation or motion sensitive equipment. Current practice for monitoring vibrations in the vicinity of construction sites commonly consists of measuring free field or structural motions using velocity transducers connected to a portable data acquisition unit via cables. This paper describes an innovative way to collect, process, transmit, and analyze vibration measurements obtained at construction sites. The system described measures vibration at the sensor location, performs necessary signal conditioning and digitization, and sends data to a Web server using wireless data transmission and Internet protocols. A Servlet program running on the Web server accepts the transmitted data and incorporates it into a project database. Two-way interaction between the Web-client and the Web server is accomplished through the use of a Servlet program and a Java Applet running inside a browser located on the Web client's computer. Advantages of this system over conventional vibration data logging systems include continuous unattended monitoring, reduced costs associated with field data collection, instant access to data files and graphs by project team members, and the ability to remotely modify data sampling schemes.

  8. Hands of early primates.

    PubMed

    Boyer, Doug M; Yapuncich, Gabriel S; Chester, Stephen G B; Bloch, Jonathan I; Godinot, Marc

    2013-12-01

    Questions surrounding the origin and early evolution of primates continue to be the subject of debate. Though anatomy of the skull and inferred dietary shifts are often the focus, detailed studies of postcrania and inferred locomotor capabilities can also provide crucial data that advance understanding of transitions in early primate evolution. In particular, the hand skeleton includes characteristics thought to reflect foraging, locomotion, and posture. Here we review what is known about the early evolution of primate hands from a comparative perspective that incorporates data from the fossil record. Additionally, we provide new comparative data and documentation of skeletal morphology for Paleogene plesiadapiforms, notharctines, cercamoniines, adapines, and omomyiforms. Finally, we discuss implications of these data for understanding locomotor transitions during the origin and early evolutionary history of primates. Known plesiadapiform species cannot be differentiated from extant primates based on either intrinsic hand proportions or hand-to-body size proportions. Nonetheless, the presence of claws and a different metacarpophalangeal [corrected] joint form in plesiadapiforms indicate different grasping mechanics. Notharctines and cercamoniines have intrinsic hand proportions with extremely elongated proximal phalanges and digit rays relative to metacarpals, resembling tarsiers and galagos. But their hand-to-body size proportions are typical of many extant primates (unlike those of tarsiers, and possibly Teilhardina, which have extremely large hands). Non-adapine adapiforms and omomyids exhibit additional carpal features suggesting more limited dorsiflexion, greater ulnar deviation, and a more habitually divergent pollex than observed plesiadapiforms. Together, features differentiating adapiforms and omomyiforms from plesiadapiforms indicate increased reliance on vertical prehensile-clinging and grasp-leaping, possibly in combination with predatory behaviors in

  9. No Telescoping Effect with Dual Tendon Vibration

    PubMed Central

    Bellan, Valeria; Wallwork, Sarah B.; Stanton, Tasha R.; Reverberi, Carlo; Gallace, Alberto; Moseley, G. Lorimer

    2016-01-01

    The tendon vibration illusion has been extensively used to manipulate the perceived position of one’s own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration) on both ‘upward-downward’ and ‘towards-away from the elbow’ planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a ‘telescoping’ effect). Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow), but no evidence of a contraction of the perceived arm length. PMID:27305112

  10. Vibration ride comfort criteria

    NASA Technical Reports Server (NTRS)

    Dempsey, T. K.; Leatherwood, J. D.

    1976-01-01

    Results are presented for an experimental study directed to derive equal vibration discomfort curves, to determine the influence of vibration masking in order to account for the total discomfort of any random vibration, and to develop a scale of total vibration discomfort in the case of human response to whole-body vertical vibration. Discomfort is referred to as a subjective discomfort associated with the acceleration level of a particular frequency band. It is shown that passenger discomfort to whole-body vibration increases linearly with acceleration level for each frequency. Empirical data provide a mechanism for determining the degree of masking (or summation) of the discomfort of multiple frequency vibration. A scale for the prediction of passenger discomfort is developed.

  11. Viral hepatitis: a sexually transmitted disease?

    PubMed

    Buzby, M

    1996-03-01

    Sexually transmitted diseases (STDs) are often discussed in the context of herpes, gonorrhea, chlamydia, and AIDS. Viral hepatitis, specifically hepatitis B, is also an STD often omitted from these discussions. The incidence of hepatitis B virus (HBV) is variable throughout the world. In North America, the highest incidence occurs in patients who are between the ages of 15 and 25 years. Safe and effective vaccines are available to prevent HBV infection, which has an associated increased risk of chronic liver disease and hepatocellular carcinoma in the carrier state. Hepatitis C virus (HCV) is a newly identified hepatotrophic virus that may also be sexually transmitted. There are no vaccines for the prevention of HCV infection and the majority of those who are infected become chronic carriers with chronic liver disease. Discussions focused on the prevention of STDs must include counseling for the prevention of HBV and HCV. PMID:8788658

  12. Current Concepts in Bacterial Sexually Transmitted Diseases

    PubMed Central

    2011-01-01

    Sexually transmitted diseases (STDs) are the most common infectious diseases worldwide, with over 350 million new cases occurring each year, and have far-reaching health, social, and economic consequences. Failure to diagnose and treat STDs at an early stage may result in serious complications and sequelae. STDs are passed from person to person primarily by sexual contact and are classified into varied groups. Some cause mild, acute symptoms and some are life-threatening. They are caused by many different infectious organisms and are treated in different ways. Syphilis and gonorrhea are ancient afflictions. Now, however, Chlamydia is prevalent and has become the most common bacterial STD. Antimicrobial resistance of several sexually transmitted pathogens is increasing, rendering some regimens ineffective, adding to therapeutic problems. A standardized treatment protocol for STDs is recommended to ensure that all patients receive adequate treatment. Appropriate treatment of STDs is an important public health measure. PMID:22025952

  13. Advances in understanding paternally transmitted Chromosomal Abnormalities

    SciTech Connect

    Marchetti, F; Sloter, E; Wyrobek, A J

    2001-03-01

    Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.

  14. AUTOMATIC HAND COUNTER

    DOEpatents

    Mann J.R.; Wainwright, A.E.

    1963-06-11

    An automatic, personnel-operated, alpha-particle hand monitor is described which functions as a qualitative instrument to indicate to the person using it whether his hands are cold'' or hot.'' The monitor is activated by a push button and includes several capacitor-triggered thyratron tubes. Upon release of the push button, the monitor starts the counting of the radiation present on the hands of the person. If the count of the radiation exceeds a predetermined level within a predetermined time, then a capacitor will trigger a first thyratron tube to light a hot'' lamp. If, however, the count is below such level during this time period, another capacitor will fire a second thyratron to light a safe'' lamp. (AEC)

  15. Imaging Arrays With Improved Transmit Power Capability

    PubMed Central

    Zipparo, Michael J.; Bing, Kristin F.; Nightingale, Kathy R.

    2010-01-01

    Bonded multilayer ceramics and composites incorporating low-loss piezoceramics have been applied to arrays for ultrasound imaging to improve acoustic transmit power levels and to reduce internal heating. Commercially available hard PZT from multiple vendors has been characterized for microstructure, ability to be processed, and electroacoustic properties. Multilayers using the best materials demonstrate the tradeoffs compared with the softer PZT5-H typically used for imaging arrays. Three-layer PZT4 composites exhibit an effective dielectric constant that is three times that of single layer PZT5H, a 50% higher mechanical Q, a 30% lower acoustic impedance, and only a 10% lower coupling coefficient. Application of low-loss multilayers to linear phased and large curved arrays results in equivalent or better element performance. A 3-layer PZT4 composite array achieved the same transmit intensity at 40% lower transmit voltage and with a 35% lower face temperature increase than the PZT-5 control. Although B-mode images show similar quality, acoustic radiation force impulse (ARFI) images show increased displacement for a given drive voltage. An increased failure rate for the multilayers following extended operation indicates that further development of the bond process will be necessary. In conclusion, bonded multilayer ceramics and composites allow additional design freedom to optimize arrays and improve the overall performance for increased acoustic output while maintaining image quality. PMID:20875996

  16. [Skin and hand disinfection].

    PubMed

    Mathis, U

    1991-04-01

    In modern medicine, hygiene has become an issue of ever increasing importance. Disinfection of hands is crucial, since hands are the main vector of bacteria. Successful disinfection depends not only on the appropriate choice of an active agent, but equally so on proper techniques and skin care. The spectre and the time profile of activity as well as the skin-protecting properties of the chosen disinfectant must be known. Basic knowledge of disinfection is necessary for a rational interpretation of the information given in the glossy printed material of advertisement. PMID:1858061

  17. Portable hand hold device

    NASA Technical Reports Server (NTRS)

    Redmon, Jr., John W. (Inventor); McQueen, Donald H. (Inventor); Sanders, Fred G. (Inventor)

    1990-01-01

    A hand hold device (A) includes a housing (10) having a hand hold (14) and clamping brackets (32,34) for grasping and handling an object. A drive includes drive lever (23), spur gear (22), and rack gears (24,26) carried on rods (24a, 26a) for moving the clamping brackets. A lock includes ratchet gear (40) and pawl (42) biased between lock and unlock positions by a cantilever spring (46,48) and moved by handle (54). Compliant grip pads (32b, 34b) provide compliance to lock, unlock, and hold an object between the clamp brackets.

  18. [Hands cutaneous exam].

    PubMed

    Lorette, Gérard; Samimi, Mahtab

    2013-12-01

    There are four different areas to consider: palms, back of the hands, fingers, periungual folds (and nails). Palmoplantar keratodermas are a group of inherited or acquired disorders. Dysidrosis is a peculiar form of eczema on the palms and lateral aspects of the fingers. SAPHO syndrome (Synovitis - Acne - Pustulosis - Hyperostosis - Osteomyelitis) presents pustules on palms. Photo-ageing is frequently noticed on the back of the hands. Paraneoplastic acrokeratosis (Bazex syndrome) affects the nose, ears, and periungual folds of fingers and toes. Spontaneous blue finger syndrome can be a benign process that resolves rapidly. PMID:24157184

  19. Vibration welding system with thin film sensor

    DOEpatents

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  20. Force reflecting hand controller

    NASA Technical Reports Server (NTRS)

    Mcaffee, Douglas A. (Inventor); Snow, Edward R. (Inventor); Townsend, William T. (Inventor)

    1993-01-01

    A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

  1. Three-Fingered Robot Hand

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.; Salisbury, J. K.

    1984-01-01

    Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.

  2. American Association for Hand Surgery

    MedlinePlus

    ... for Wrist Injuries: A Brief Literature Update HAND Journal HAND , the official Journal of AAHS HAND is the official peer-reviewed Journal of AAHS, featuring articles written by clinicians worldwide ...

  3. Hands-on Humidity.

    ERIC Educational Resources Information Center

    Pankiewicz, Philip R.

    1992-01-01

    Presents five hands-on activities that allow students to detect, measure, reduce, and eliminate moisture. Students make a humidity detector and a hygrometer, examine the effects of moisture on different substances, calculate the percent of water in a given food, and examine the absorption potential of different desiccants. (MDH)

  4. Learning "Hands On."

    ERIC Educational Resources Information Center

    Ritter, Janice T.

    2001-01-01

    Discusses a computer teacher's incorporation of hand-held computer technology into her third- and fifth-grade students' study of acid rain. The project successfully brought two grade levels together for cross-grade research, provided an opportunity for classroom teachers and technology specialists to work collaboratively, and enhanced students'…

  5. Mechanical cornpicker hand injuries.

    PubMed

    Momcilović, Dragan; Prokes, Bela; Janjić, Zlata

    2005-01-01

    Mechanical cornpicker hand injuries are not frequent in comparison to general hand trauma, but they have a specific mechanism of occurrence and are very severe. This investigation included 221 hand injuries. The sex distribution shows a general male dominance (85.25%) in their active age (84.44%). These are, seasonal injuries mostly occurring in October (75.11%). By type of injuries, mutilating crush injuries are most frequent (64.25%). After completing the treatment, in most cases the functional result were estimated as bad (50.68%). Data concerning education and trainig for operating agricultural machines (96.38%--patients without training) and carrying out safety measures (63.35% of injured patients did not apply any protection measures) are devastating. The number of these injuries, as well as consequent permanent disabilities, may be considerably reduced by preventive measures, inclulding public health services and media. Use of contempoarary agricultural machinery, as well as obligatory training for operating these machines and application of protective measures, may also reduce the incidence of hand injuries during corn picking. PMID:16526250

  6. Hands On Earth Science.

    ERIC Educational Resources Information Center

    Weisgarber, Sherry L.; Van Doren, Lisa; Hackathorn, Merrianne; Hannibal, Joseph T.; Hansgen, Richard

    This publication is a collection of 13 hands-on activities that focus on earth science-related activities and involve students in learning about growing crystals, tectonics, fossils, rock and minerals, modeling Ohio geology, geologic time, determining true north, and constructing scale-models of the Earth-moon system. Each activity contains…

  7. A Helping Hand.

    ERIC Educational Resources Information Center

    Wilke, Arnie

    2003-01-01

    Describes steps schools can take to provide cleaner and safer washrooms. Emphasizes hand-washing to battle germs and asserts that creating a comfortable and user-friendly washroom is a critical and often overlooked aspect for encouraging better hygiene habits. (EV)

  8. Electrically powered hand tool

    DOEpatents

    Myers, Kurt S.; Reed, Teddy R.

    2007-01-16

    An electrically powered hand tool is described and which includes a three phase electrical motor having a plurality of poles; an electrical motor drive electrically coupled with the three phase electrical motor; and a source of electrical power which is converted to greater than about 208 volts three-phase and which is electrically coupled with the electrical motor drive.

  9. Hands-On Hydrology

    ERIC Educational Resources Information Center

    Mathews, Catherine E.; Monroe, Louise Nelson

    2004-01-01

    A professional school and university collaboration enables elementary students and their teachers to explore hydrology concepts and realize the beneficial functions of wetlands. Hands-on experiences involve young students in determining water quality at field sites after laying the groundwork with activities related to the hydrologic cycle,…

  10. Hands-on Herps.

    ERIC Educational Resources Information Center

    Science Activities, 1987

    1987-01-01

    Presents a hands-on activity to help primary, intermediate, and advanced students learn about and compare the general characteristics of reptiles and amphibians. Suggests "herp stations" to provide experiences. Details materials, background and procedures necessary for using this activity. (CW)

  11. Rotationally Actuated Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.

  12. Vibration Transmission through Bearings with Application to Gearboxes

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    2007-01-01

    Cabin noise has become a major concern to manufacturers and users of helicopters. Gear noise is the largest part of this unwanted sound. The crucial noise path is generally considered to be from the gears through the gear-supporting shafts and bearings into the gearbox case, and from there either through the gearbox mounts or the surrounding air to the helicopter cabin. If the noise, that is, the gear and shaft vibration, can be prevented from traveling through the gearbox bearings, then the noise cannot make its way into the helicopter cabin. Thus the vibration-transmitting properties of bearings are of paramount importance. This paper surveys the literature concerning evaluation of properties for the types of bearings used in helicopter gearboxes. A simple model is proposed to evaluate vibration transmission, using measured or calculated bearing stiffness and damping. Less-commonly used types of gearbox bearings (e.g., fluid film) are evaluated for their potential in reducing vibration transmission.

  13. Comparison of surgical hand scrub and alcohol surgical hand rub on reducing hand microbial burden.

    PubMed

    Ghorbani, Azam; Shahrokhi, Akram; Soltani, Zahra; Molapour, Azam; Shafikhani, Mahin

    2012-02-01

    This study was performed to compare the effects of two hand decontamination methods on the microbial burden of operating room staff hands. The surgical hand washing methods compared were a traditional surgical hand scrub using a povidone iodine solution, and a social wash using a liquid non-antibacterial soap followed by the application of an alcoholic hand rub. PMID:22724306

  14. Vibration injuries in Norwegian forest workers

    PubMed Central

    Hellstr⊘m, B.; Andersen, K. Lange

    1972-01-01

    Hellstr⊘m, B., and Lange Andersen, K. (1972).Brit. J. industr. Med.,29, 255-263. Vibration injuries in Norwegian forest workers. A free medical examination with compensation for lost earnings was offered to the forest workers in three areas of eastern Norway. Sixty-six per cent attended (413 workers, of whom 296 used chain saws). The prevalence of Raynaud's phenomenon (RP) was 47% in chain saw operators, 14% in forest workers not exposed to vibration, and 9% in 302 indoor workers not exposed to vibration. The high prevalence of RP in chain saw operators was attributed to a traumatic vasospastic disease (TVD). The average time of latency was eight years. The standard symptoms of TVD were attacks of blanching and numbness. Cyanosis and pain occurred rarely. In subsamples, measurements of tactile two-point discrimination and maximal isometric muscle strength (hand grip and finger pressure) as well as x-ray examinations of the wrists and the hands gave no evidence of vibration injury to peripheral nerves, muscles, bones, or joints. PMID:5044596

  15. Are migratory behaviours of bats socially transmitted?

    PubMed

    Baerwald, E F; Barclay, R M R

    2016-04-01

    To migrate, animals rely on endogenous, genetically inherited programmes, or socially transmitted information about routes and behaviours, or a combination of the two. In long-lived animals with extended parental care, as in bats, migration tends to be socially transmitted rather than endogenous. For a young bat to learn migration via social transmission, they would need to follow an experienced individual, most likely one roosting nearby. Therefore, we predicted that bats travelling together originate from the same place. It is also likely that young bats would follow their mothers or other kin, so we predicted that bats travelling together are more closely related to each other than bats not travelling together. To test our predictions, we used microsatellite genotypes and stable isotope values of δ (13)C, δ (15)N and δ (2)H to analyse the relatedness and geographical origins of migrating hoary bats (Lasiurus cinereus/Aeorestes cinereus (Baird et al. 2015 J. Mammal. 96, 1255-1274 (doi:10.1093/jmammal/gyv135)); n = 133) and silver-haired bats (Lasionycteris noctivagans; n = 87) killed at wind turbines over two consecutive autumn migrations. Contrary to our predictions, there was no evidence that related dyads of hoary bats or silver-haired bats were killed on the same night more frequently than expected by chance, or that the number of days between the fatalities of dyad members was influenced by relatedness or latitude of origin. Our data suggest that these bats do not socially transmit migration routes and behaviours among close kin. PMID:27152208

  16. Are migratory behaviours of bats socially transmitted?

    PubMed Central

    Baerwald, E. F.; Barclay, R. M. R.

    2016-01-01

    To migrate, animals rely on endogenous, genetically inherited programmes, or socially transmitted information about routes and behaviours, or a combination of the two. In long-lived animals with extended parental care, as in bats, migration tends to be socially transmitted rather than endogenous. For a young bat to learn migration via social transmission, they would need to follow an experienced individual, most likely one roosting nearby. Therefore, we predicted that bats travelling together originate from the same place. It is also likely that young bats would follow their mothers or other kin, so we predicted that bats travelling together are more closely related to each other than bats not travelling together. To test our predictions, we used microsatellite genotypes and stable isotope values of δ13C, δ15N and δ2H to analyse the relatedness and geographical origins of migrating hoary bats (Lasiurus cinereus/Aeorestes cinereus (Baird et al. 2015 J. Mammal. 96, 1255–1274 (doi:10.1093/jmammal/gyv135)); n = 133) and silver-haired bats (Lasionycteris noctivagans; n = 87) killed at wind turbines over two consecutive autumn migrations. Contrary to our predictions, there was no evidence that related dyads of hoary bats or silver-haired bats were killed on the same night more frequently than expected by chance, or that the number of days between the fatalities of dyad members was influenced by relatedness or latitude of origin. Our data suggest that these bats do not socially transmit migration routes and behaviours among close kin. PMID:27152208

  17. Preventing sexually transmitted infections: back to basics.

    PubMed

    Rompalo, Anne

    2011-12-01

    Sexually transmitted infections (STIs) have plagued humans for millennia and can result in chronic disease, pregnancy complications, infertility, and even death. Recent technological advances have led to a better understanding of the causative agents for these infections as well as aspects of their pathogenesis that might represent novel therapeutic targets. The articles in this Review Series provide excellent updates on the recent advances in understanding of the pathogenesis of some very important and persistent STIs and discuss the importance of considering each pathogen in the broader context of the environment of the individual who it infects. PMID:22133882

  18. [Pseudo-scabies transmitted by red fox].

    PubMed

    Birk, R W; Tebbe, B; Schein, E; Zouboulis, C C; Orfanos, C E

    1999-02-01

    Pseudoscabies, i.e. infestation of human skin with animal mites may occasionally occur and should be considered in the differential diagnosis of pruritic and papular skin disease. We report here on a 52-year-old woman with pseudoscabies or canine scabies (Sarcoptes scabiei var. canis), transmitted by indirect contact with a red fox in the urban area of Berlin. Red foxes may live in unhabited areas of metropolitan large cities, i.e. in garages, car wrecks and cellars. Full remission of the prolonged and pruritic rush was seen after topical administration of lindane together with systemic corticosteroids. PMID:10097956

  19. Optical smart packaging to reduce transmitted information.

    PubMed

    Cabezas, Luisa; Tebaldi, Myrian; Barrera, John Fredy; Bolognini, Néstor; Torroba, Roberto

    2012-01-01

    We demonstrate a smart image-packaging optical technique that uses what we believe is a new concept to save byte space when transmitting data. The technique supports a large set of images mapped into modulated speckle patterns. Then, they are multiplexed into a single package. This operation results in a substantial decreasing of the final amount of bytes of the package with respect to the amount resulting from the addition of the images without using the method. Besides, there are no requirements on the type of images to be processed. We present results that proof the potentiality of the technique. PMID:22274339

  20. Sexually transmitted infections manifesting as proctitis.

    PubMed

    Lamb, Chris A; Lamb, Elizabeth Iris Mary; Mansfield, John C; Sankar, K Nathan

    2013-01-01

    There is a rising incidence of several sexually transmitted infections (STIs), many of which can present with proctitis. Causative organisms include Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus, Treponema pallidum (syphilis), Giardia lamblia (giardiasis) and Entamoeba histolytica (amoebiasis). This paper outlines important clinical discriminators and key investigations to distinguish these organisms from non-infective pathology that include inflammatory bowel disease, solitary rectal ulcer syndrome and Behçet's syndrome. Management of these infections is described and suggestions are made for successful gastroenterology clinical consultation when an STI is suspected. PMID:23914292

  1. [Modern diagnosis of sexually transmitted diseases].

    PubMed

    Brockmeyer, N H; Meyer, T

    2016-01-01

    Diagnosis of sexually transmitted diseases (STD) has significantly improved in recent years by the application of nucleic acid amplification tests (NAAT). In addition to detection of infectious agents, molecular methods were also used for characterization of pathogens (typing, genotypic resistance testing). In contrast to conventional Sanger sequencing of amplicons, new sequencing technologies (next generation sequencing) are able to identify resistant variants that represent only small minorities in a heterogeneous population. NAATs are also available as fully automated closed systems that can be run independently of centralized laboratories and will become increasingly important for point-of-care testing. PMID:26646440

  2. Transmitting drilling data rig to office

    SciTech Connect

    Taylor, K.O.

    1985-08-12

    Rig-to-office data telecommunications is discussed in this article as a practical and promising solution to rig-site data overload. The barrage of rig data that includes monitoring while drilling, mud logging, wireline logging, directional, drillstring configuration, operational, weather, crew data, etc., is collected on the well site and then transmitted into an oil or service company office for expert and/or computer analysis. Through this approach, the best expertise of the oil and service companies can be applied to many wells. Real time systems and batch systems are reviewed in this article.

  3. Drilling with fiber-transmitted, visible lasers

    SciTech Connect

    Kautz, D.D.; Berzins, L.V.; Dragon, E.P.; Werve, M.E.; Warner, B.E.

    1994-02-17

    High power and radiance copper-vapor laser technology developed at Lawrence Livermore National Laboratory shows great promise for many materials processing tasks. The authors recently transmitted the visible light produced by these lasers through fiber optics to perform hole drilling experiments. They found the tolerances on the hole circulatory and cylindricity to be excellent when compared to that produced by conventional optics. This technique lends itself to many applications that are difficult to perform when using conventional optics, including robotic manipulation and hole drilling in non-symmetric parts.

  4. Effect of remote sensory noise on hand function post stroke.

    PubMed

    Seo, Na Jin; Kosmopoulos, Marcella Lyn; Enders, Leah R; Hur, Pilwon

    2014-01-01

    Hand motor impairment persists after stroke. Sensory inputs may facilitate recovery of motor function. This pilot study tested the effectiveness of tactile sensory noise in improving hand motor function in chronic stroke survivors with tactile sensory deficits, using a repeated measures design. Sensory noise in the form of subthreshold, white noise, mechanical vibration was applied to the wrist skin during motor tasks. Hand dexterity assessed by the Nine Hole Peg Test and the Box and Block Test and pinch strength significantly improved when the sensory noise was turned on compared with when it was turned off in chronic stroke survivors. The subthreshold sensory noise to the wrist appears to induce improvements in hand motor function possibly via neuronal connections in the sensoriomotor cortex. The approach of applying concomitant, unperceivable mechanical vibration to the wrist during hand motor tasks is easily adoptable for clinic use as well as unsupervised home use. This pilot study suggests a potential for a wristband-type assistive device to complement hand rehabilitation for stroke survivors with sensorimotor deficit. PMID:25477806

  5. Transmission of Enterobius vermicularis eggs through hands of school children in rural South Africa.

    PubMed

    Cranston, Imogen; Potgieter, Natasha; Mathebula, Sammy; Ensink, Jeroen H J

    2015-10-01

    Enterobius vermicularis is a helminth that is difficult to control, is found globally, especially in crowded conditions, and can be transmitted from person to person by contaminated hands. A newly developed method for the quantification of helminth eggs on hands was tested among schoolchildren in a rural South African region to look at the role hands play in helminth infection, and to determine the risk factors for hand contamination. The study found 16.6% of participants' hands positive for helminth eggs, with E. vermicularis most commonly identified. Egg concentrations on hands ranged from 0 to 57 eggs/2 hands. Gender, toilet type used at home, and not reporting to wash hands with soap before eating were all associated with the presence of eggs on hands. The study highlights the need to improve sanitation facilities, and promote handwashing with soap in schools to prevent transmission of E. vermicularis. PMID:26169761

  6. Method and system for vertical seismic profiling by measuring drilling vibrations

    SciTech Connect

    Ng, F.W.; DiSiena, J.P.; Bseisu, A.A.

    1990-10-23

    This patent describes a method for obtaining seismic data pertaining to an earth formation while forming a wellbore in the formation with a drillstring having a drillbit or the like disposed at the lower distal end thereof. It comprises: providing vibration sensing means connected to an upper region of the drillstring. The vibration sensing means being adapted to produce electrical signals related to vibrations of the drillstring; providing an array of seismometers disposed generally on the earth's surface in the vicinity of the wellbore; measuring first signals generated by the vibration sensing means resulting from vibrations of the drillstring; measuring second signals generated by the array of seismometers resulting from vibrations transmitted through the formation; and comparing the first signals and the second signals to determine selected characteristics of the formation including the step of calculating the location of origin of the first signal based on the difference in time of arrival at the vibration sensing means of a torsional vibration signal and an axial vibration signal transmitted through the drillstring and at least one of the torsional wave speed and the axial wave speed in the drillstring to determine the origin in time of the first signal.

  7. Vibration study of the APS magnet support assemblies

    SciTech Connect

    Wambsganss, M.W.; Jendrzejczyk, J.A.; Chen, S.S.

    1990-11-01

    Stability of the positron closed orbit is a requirement for successful operation of the Advanced Photon Source. The fact that vibration of the storage ring quadrupole magnets can lead to distortion of the positron closed orbit and to potentially unacceptable beam emittance growth provides the motivation for the subject studies. Low frequency vibrations can be controlled with steering magnets using feedback systems, provided the vibration amplitudes are within the dynamic range of the controllers. High frequency vibration amplitudes, on the other hand, are out of the range of the controller and, therefore must be limited to ensure the emittance growth will not exceed a prescribed value. Vibration criteria were developed based on the requirement that emittance growth be limited to 10 percent. Recognizing that the quadrupole magnets have the most significant effect, three different scenarios were considered: vibration of a single quadrupole within the storage ring, random vibration of all the quadrupoles in the ring, and the hypothetical case of a plane wave sweeping across the site and the quadrupoles following the motion of the plane wave. The maximum allowable peak vibration amplitudes corresponding to these three vibration scenarios are given. The criteria associated with the passage of a plane wave is dependent on wavelength, or, alternatively, on frequency given the wave speed. The wave speed used is that measured as a part of the geotechnical investigation at the APS site.

  8. Sexually transmitted diseases in children in developing countries.

    PubMed

    Richens, J

    1994-08-01

    The populations of developing countries have younger age structures than the populations of more developed, Western countries. That is, children, adolescents, and youth constitute a far greater proportion of the populations of developing countries than in developed countries. These young people experiment with sex and sexual intercourse or have coitus on a regular basis depending upon their individual personalities and circumstances. The prevalence of sexually transmitted diseases (STD) among younger age groups in developing countries is not well documented. It may, however, be inferred on the basis of reported experience of STD in surveys of adolescents and young adults that many children are infected with STDs. Some young people have sex consensually, some are coaxed into it, and others are coerced. On the one hand, young children have been thought to contract STD by sitting on the laps of infected, scantily-clad adults where such limited attire is the norm. Close contact between youngsters such as communal sleeping, for example, could then facilitate the spread of the STD among children. Sex, consensual or otherwise, is not involved in such infection and transmission beyond the index adult. On the other hand, however, many children and adolescents are forced to have sexual relations and/or intercourse either directly against their will or as a result of the primal need to ensure their individual survival. For example, there are an estimated 100-200 million street children worldwide; many have little alternative but to sell sex to survive. When having sex, they may not use condoms because they are unaware of the STD risk they face, they have no access to free condoms, clients/employers/peers prevent them from using condoms, or due to a myriad of other reasons. Struggling to survive, many such kids place condom use very low on their list of priorities. Children and adolescents can also become infected and transmit STDs to others by engaging in sexual intercourse

  9. Adaptive vibration energy harvesting

    NASA Astrophysics Data System (ADS)

    Behrens, Sam; Ward, John; Davidson, Josh

    2007-04-01

    By scavenging energy from their local environment, portable electronic devices such as mobile phones, radios and wireless sensors can achieve greater run-times with potentially lower weight. Vibration energy harvesting is one such approach where energy from parasitic vibrations can be converted into electrical energy, through the use of piezoelectric and electromagnetic transducers. Parasitic vibrations come from a range of sources such as wind, seismic forces and traffic. Existing approaches to vibration energy harvesting typically utilise a rectifier circuit, which is tuned to the resonant frequency of the harvesting structure and the dominant frequency of vibration. We have developed a novel approach to vibration energy harvesting, including adaption to non-periodic vibrations so as to extract the maximum amount of vibration energy available. Experimental results of an experimental apparatus using off-the-shelf transducer (i.e. speaker coil) show mechanical vibration to electrical energy conversion efficiencies of 27 - 34%. However, simulations of a more electro-mechanical efficient and lightly damped transducer show conversion efficiencies in excess of 80%.

  10. Combination hand rejuvenation procedures.

    PubMed

    Shamban, Ava T

    2009-01-01

    Although the hands age at the same rate as the face, the aging process differs and requires a combination treatment approach for optimal rejuvenation. Photoaging causes epidermal changes such as lentigines, actinic keratoses, fine wrinkles, and crepe-like textural change. Thinning of the dermis and subcutaneous fat occurs as a result of both ultraviolet light exposure and intrinsic aging. This process can lead to a skeletal appearance of the hands, with prominent veins and bulging tendons. The combination approach addresses all of these issues, employing lasers, intense pulsed light devices, fractional devices, fillers, peels, vein sclerotherapy, and an effective at-home skin care program as indicated for individual needs and concerns. PMID:19825471

  11. Tropical Diabetic Hand Syndrome

    PubMed Central

    Okpara, TC; Ezeala-Adikaibe, BA; Omire, O; Nwonye, E; Maluze, J

    2015-01-01

    Any adult with diabetes in the tropics with hand cellulitis, infection and gangrene qualifies for tropical diabetic hand syndrome (TDHS). We reviewed a 39-year-old woman with a 3-week history of swelling of the left index finger following an insect bite. The swelling progressively increased in size, was very painful, and extended to the palm. There was no history or symptoms suggestive of chronic complications of diabetes. Random blood sugar on presentation was above 600 mg/dl using a glucometer. Examination revealed an edematous left palm draining pus from multiple sinuses, necrotic and gangrenous left index finger extending down to just above the thenar eminence. A diagnosis of TDHS in a patient with hyperosmolar state was made. She was managed accordingly and subsequently underwent aggressive debridement and desloughing. Two fingers were amputated and the wound was allowed to heal by secondary intention. PMID:27057390

  12. Tropical Diabetic Hand Syndrome.

    PubMed

    Okpara, T C; Ezeala-Adikaibe, B A; Omire, O; Nwonye, E; Maluze, J

    2015-01-01

    Any adult with diabetes in the tropics with hand cellulitis, infection and gangrene qualifies for tropical diabetic hand syndrome (TDHS). We reviewed a 39-year-old woman with a 3-week history of swelling of the left index finger following an insect bite. The swelling progressively increased in size, was very painful, and extended to the palm. There was no history or symptoms suggestive of chronic complications of diabetes. Random blood sugar on presentation was above 600 mg/dl using a glucometer. Examination revealed an edematous left palm draining pus from multiple sinuses, necrotic and gangrenous left index finger extending down to just above the thenar eminence. A diagnosis of TDHS in a patient with hyperosmolar state was made. She was managed accordingly and subsequently underwent aggressive debridement and desloughing. Two fingers were amputated and the wound was allowed to heal by secondary intention. PMID:27057390

  13. Alien Hand Syndrome.

    PubMed

    Hassan, Anhar; Josephs, Keith A

    2016-08-01

    Alien hand syndrome (AHS) is a rare disorder of involuntary limb movement together with a sense of loss of limb ownership. It most commonly affects the hand, but can occur in the leg. The anterior (frontal, callosal) and posterior variants are recognized, with distinguishing clinical features and anatomical lesions. Initial descriptions were attributed to stroke and neurosurgical operations, but neurodegenerative causes are now recognized as most common. Structural and functional imaging and clinical studies have implicated the supplementary motor area, pre-supplementary motor area, and their network connections in the frontal variant of AHS, and the inferior parietal lobule and connections in the posterior variant. Several theories are proposed to explain the pathophysiology. Herein, we review the literature to update advances in the understanding of the classification, pathophysiology, etiology, and treatment of AHS. PMID:27315251

  14. Hand tools: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A selection of new hand tools, modifications of existing tools, and techniques developed in the course of NASA research and development projects are presented. The items are presented in two sections: tools for cable and connector applications, and tools for welding applications. Safety is emphasized, together with ease of operation and use in restricted areas or hazardous environments. The discussions are directed primarily toward the technician engaged in assembly or maintenance of mechanical or electrical equipment.

  15. Pediatric hand treadmill injuries.

    PubMed

    Banever, Gregory T; Moriarty, Kevin P; Sachs, Barry F; Courtney, Richard A; Konefal, Stanley H; Barbeau, Lori

    2003-07-01

    The great popularity of physical fitness in modern society has brought many pieces of exercise equipment into our homes for convenience and privacy. This trend has come with an increasing rate of injuries to children who curiously touch moving parts, including treadmill belts. Experience with a recent series of treadmill contact burns to children's hands is described in this article. A retrospective chart review at a tertiary referral center from June 1998 until June 2001 found six children sustaining hand burns from treadmills. The patients' ages at presentation ranged from 15 to 45 months (average of 31 months, three boys and three girls). All injuries occurred in the home while a parent was using the treadmill. Burns involved the palmar aspect of the hand, mostly confined to the fingers, and the severity ranged from partialto full-thickness burns. All patients were initially managed with collagenase and bacitracin zinc/polymyxin B powder dressings to second- and third-degree burns, along with splinting and range-of-motion exercises. Two patients required skin grafting at 2 weeks and 2 months for full-thickness tissue loss and tight joint contracture, respectively. At an average follow-up of 12 months, all patients had full range of motion and no physical limitation. The rate of children injured by exercise equipment is expected to increase. Friction burns to the hands remain a concern, although early recognition and appropriate management are associated with excellent functional outcomes. Protective modification of exercise machines seems to be the best approach to eliminating these injuries. PMID:12867861

  16. Acoustic and Vibration Environment for Crew Launch Vehicle Mobile Launcher

    NASA Technical Reports Server (NTRS)

    Vu, Bruce T.

    2007-01-01

    A launch-induced acoustic environment represents a dynamic load on the exposed facilities and ground support equipment (GSE) in the form of random pressures fluctuating around the ambient atmospheric pressure. In response to these fluctuating pressures, structural vibrations are generated and transmitted throughout the structure and to the equipment items supported by the structure. Certain equipment items are also excited by the direct acoustic input as well as by the vibration transmitted through the supporting structure. This paper presents the predicted acoustic and vibration environments induced by the launch of the Crew Launch Vehicle (CLV) from Launch Complex (LC) 39. The predicted acoustic environment depicted in this paper was calculated by scaling the statistically processed measured data available from Saturn V launches to the anticipated environment of the CLV launch. The scaling was accomplished by using the 5-segment Solid Rocket Booster (SRB) engine parameters. Derivation of vibration environment for various Mobile Launcher (ML) structures throughout the base and tower was accomplished by scaling the Saturn V vibration environment.

  17. Artificial dexterous hand

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    An artificial dexterous hand is provided for grasping and manipulating objects. The hand includes left and right thumbs that are operatively connected to an engagement assembly which causes movement of the left and right thumbs. The left thumb has a left thumb base and is movable about three separate first left thumb axes which run through the left thumb base. Correspondingly, the right thumb has a right thumb base and is movable about three separate first right thumb axes which run through the right thumb base. The engagement assembly has a gear assembly which is operatively connected to a motor assembly. Upon actuation by the motor assembly, the gear assembly causes movement of the left and right thumbs about the first left thumb axes and first right thumb axes respectively. The hand can also have a center finger which is operatively connected to the engagement assembly and which is interposed between the left and right thumbs. The finger has a finger base and is movable about two separate first finger axes running through the finger base. Therefore, upon actuation by the motor assembly, the gear assembly will also cause movement of the finger about the first finger axes.

  18. Compact Dexterous Robotic Hand

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  19. Design of power-transmitting shifts

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1984-01-01

    Power transmission shafting which is a vital element of all rotating machinery is discussed. Design methods, based on strength considerations for sizing shafts and axles to withstand both steady and fluctuating loads are summarized. The effects of combined bending, torsional, and axial loads are considered along with many application factors that are known to influence the fatigue strength of shafting materials. Methods are presented to account for variable amplitude loading histories and their influence on limited life designs. The influences of shaft rigidity, materials, and vibration on the design are discussed.

  20. Phase-only nulling for transmit antenna

    NASA Astrophysics Data System (ADS)

    Hussain, Moayyed A.; Yu, Kai-Bor

    1999-11-01

    This paper describes a technique for transmit antenna nulling for low-cost large sparse phased array radar system. Radar system described includes an array of elemental antennas, each with a transmit/receive (T/R) module. The T/R modules are operated at or near maximum output to achieve maximum CD-to-RF efficiency. A phase controller controls the phase shift, which are imparted by each module to its signal, to form a mainbeam and its associated sidelobes. A perturbation phase generator adds phase shifts computed, to form wide nulls in the sidelobe structure. The nulls are achieved at very minimal loss of gain, in the order of fraction of a dB. The speed of obtaining these nulls in real time allows a rapid steering of these nulls in a hostile environment. The thinned aperture allow designing a light weigh mobile system. In radar context, these nulls may be placed on a source of ground clutter, a set of jammers or a set of undesirable radio sources.

  1. Prevention of Soil-transmitted Helminth Infection

    PubMed Central

    Mascarini-Serra, Luciene

    2011-01-01

    Soil-transmitted helminths (STHs) form one of the most important groups of infectious agents and are the cause of serious global health problems. The most important STHs are roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus or Ancylostoma duodenale); on a global level, more than a billion people have been infected by at least one species of this group of pathogens. This review explores the general concepts of transmission dynamics and the environment and intensity of infection and morbidity of STHs. The global strategy for the control of soil-transmitted helminthiasis is based on (i) regular anthelminthic treatment, (ii) health education, (iii) sanitation and personal hygiene and (iv) other means of prevention with vaccines and remote sensoring. The reasons for the development of a control strategy based on population intervention rather than on individual treatment are discussed, as well as the costs of the prevention of STHs, although these cannot always be calculated because interventions in health education are difficult to measure. An efficient sanitation infrastructure can reduce the morbidity of STHs and eliminates the underlying cause of most poverty-related diseases and thus supports the economic development of a country. PMID:21731306

  2. Sexually transmitted diseases treatment guidelines, 2015.

    PubMed

    Workowski, Kimberly A; Bolan, Gail A

    2015-06-01

    These guidelines for the treatment of persons who have or are at risk for sexually transmitted diseases (STDs) were updated by CDC after consultation with a group of professionals knowledgeable in the field of STDs who met in Atlanta on April 30-May 2, 2013. The information in this report updates the Sexually Transmitted Diseases Treatment Guidelines, 2010 (MMWR Recomm Rep 2010;59 [No. RR-12]). These updated guidelines discuss 1) alternative treatment regimens for Neisseria gonorrhoeae; 2) the use of nucleic acid amplification tests for the diagnosis of trichomoniasis; 3) alternative treatment options for genital warts; 4) the role of Mycoplasma genitalium in urethritis/cervicitis and treatment-related implications; 5) updated HPV vaccine recommendations and counseling messages; 6) the management of persons who are transgender; 7) annual testing for hepatitis C in persons with HIV infection; 8) updated recommendations for diagnostic evaluation of urethritis; and 9) retesting to detect repeat infection. Physicians and other health-care providers can use these guidelines to assist in the prevention and treatment of STDs. PMID:26042815

  3. Adaptive contrast imaging: transmit frequency optimization

    NASA Astrophysics Data System (ADS)

    Ménigot, Sébastien; Novell, Anthony; Voicu, Iulian; Bouakaz, Ayache; Girault, Jean-Marc

    2010-01-01

    Introduction: Since the introduction of ultrasound (US) contrast imaging, the imaging systems use a fixed emitting frequency. However it is known that the insonified medium is time-varying and therefore an adapted time-varying excitation is expected. We suggest an adaptive imaging technique which selects the optimal transmit frequency that maximizes the acoustic contrast. Two algorithms have been proposed to find an US excitation for which the frequency was optimal with microbubbles. Methods and Materials: Simulations were carried out for encapsulated microbubbles of 2 microns by considering the modified Rayleigh-Plesset equation for 2 MHz transmit frequency and for various pressure levels (20 kPa up to 420kPa). In vitro experiments were carried out using a transducer operating at 2 MHz and using a programmable waveform generator. Contrast agent was then injected into a small container filled with water. Results and discussions: We show through simulations and in vitro experiments that our adaptive imaging technique gives: 1) in case of simulations, a gain of acoustic contrast which can reach 9 dB compared to the traditional technique without optimization and 2) for in vitro experiments, a gain which can reach 18 dB. There is a non negligible discrepancy between simulations and experiments. These differences are certainly due to the fact that our simulations do not take into account the diffraction and nonlinear propagation effects. Further optimizations are underway.

  4. 47 CFR 90.541 - Transmitting power limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-775 and 793-805 MHz Bands § 90.541 Transmitting power limits. The transmitting power of base, mobile, portable and control stations operating in the 769-775 MHz and 799-805 MHz frequency bands must not...

  5. Photoelectronic vibrometer with polarized light. [for torsional vibration measurements

    NASA Technical Reports Server (NTRS)

    Kremmer, I.

    1974-01-01

    A seismic torsiometer is described which is based on the reception by a photosensitive transducer of a light flux modulated by a relative rotation of the optical axes of two polaroids. The torsional vibrations of the polaroid fixed to the shaft are transmitted to the other polaroid (which at the same time is the seismic mass of the apparatus) by means of elastic lamellas. The device can work as accelerometer, vibrometer or frequency meter, depending on the value of the ratio between the proper oscillation frequency of the seismic system and the measured vibration frequency.

  6. ARhT: a portable hand therapy system.

    PubMed

    Bercht, Daniel; Boisvert, Timothy; Lowe, Joshua; Stearns, Kyle; Ganz, Aura

    2012-01-01

    We introduce ARhT (Automated Relearning hand Therapy), a portable hand therapy system that enables a user to perform physical therapy at the comfort of their own home. This reduces rehabilitation time, enhances the user experience, reduces cost and provides accountability to physical therapy sessions. ARhT complements traditional therapy methods by interacting with the user in real time and providing the patient user friendly instructions, feedback, and progress tracking. The therapist pre-selects the hand gestures that comprise every workout and can view session information on a patient to patient basis within a standalone web application. ARhT incorporates a data acquisition subsystem which houses EMG sensors and a custom computation and communication board. The sensor data is transmitted to an Android smartphone that determines the user performance and interacts with the user through a graphical user interface. Our results show that our system recognizes hand therapy gestures with over 95% accuracy. PMID:23365881

  7. 47 CFR 64.3001 - Obligation to transmit 911 calls.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Obligation to transmit 911 calls. 64.3001 Section 64.3001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Obligation to transmit 911 calls. All telecommunications carriers shall transmit all 911 calls to a PSAP,...

  8. 47 CFR 22.565 - Transmitting power limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Transmitting power limits. 22.565 Section 22... Transmitting power limits. The transmitting power of base, mobile and fixed transmitters operating on the... radiated power (ERP) of base and fixed transmitters must not exceed the applicable limits in this...

  9. [An unusual cause of hand nodule: peri-tendon dirofilariasis].

    PubMed

    Saied, W; Amara, K; Bouchoucha, S; Khaled, S; Mrad, K; Nessib, M N; Smida, M; Ben Ghachem, M

    2011-02-01

    Dirofilariasis is a zoonosis affecting dogs and cats. It was transmitted to man by mosquito bites. Human dirofilariasis is rare. We report a case of 4-year-old girl presented with a subcutaneous palmar nodule of the hand. Surgical excision shows a nodule encircling the forth flexor tendon. The histological examination established the diagnosis by the presence of an adult worm identified as Dirofilaria repens. Surgical excision was curative. PMID:21087885

  10. Portable Computer Keyboard For Use With One Hand

    NASA Technical Reports Server (NTRS)

    Friedman, Gary L.

    1992-01-01

    Data-entry device held in one hand and operated with five fingers. Contains seven keys. Letters, numbers, punctuation, and cursor commands keyed into computer by pressing keys in various combinations. Device called "data egg" used where standard typewriter keyboard unusable or unavailable. Contains micro-processor and 32-Kbyte memory. Captures text and transmits it to computer. Concept extended to computer mouse. Especially useful to handicapped or bedridden people who find it difficult or impossible to operate standard keyboards.

  11. Force limited vibration testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry D.

    1991-01-01

    A new method of conducting lab vibration tests of spacecraft equipment was developed to more closely simulate the vibration environment experienced when the spacecraft is launched on a rocket. The improved tests are tailored to identify equipment design and workmanship problems without inducing artificial failures that would not have occurred at launch. These new, less destructive types of vibration tests are essential to JPL's protoflight test approach in which lab testing is conducted using the flight equipment, often one of a kind, to save time and money. In conventional vibration tests, only the input vibratory motion is specified; the feedback, or reaction force, between the test item and the vibration machine is ignored. Most test failures occur when the test item goes into resonance, and the reaction force becomes very large. It has long been recognized that the large reaction force is a test artifact which does not occur with the lightweight, flexible mounting structures characteristic of spacecraft and space vehicles. In new vibration tests, both the motion and the force provided to the test item by the vibration machine are controlled, so that the vibration ride experienced by the test item is as in flight.

  12. [Vibration on agricultural tractors].

    PubMed

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio

    2013-01-01

    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed. PMID:24303716

  13. Vibrational Schroedinger Cats

    NASA Technical Reports Server (NTRS)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.

    1996-01-01

    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  14. Hand Controller Assembly

    NASA Technical Reports Server (NTRS)

    Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

    2015-01-01

    A user input device for a vehicular electrical system is provided. The user input device includes a handle sized and shaped to be gripped by a human hand and a gimbal assembly within the handle. The gimbal assembly includes a first gimbal component, a second gimbal component coupled to the first gimbal component such that the second gimbal component is rotatable relative to the first gimbal component about a first axis, and a third gimbal component coupled to the second gimbal component such that the third gimbal component is rotatable relative to the second gimbal component about a second axis.

  15. Vibration control in accelerators

    SciTech Connect

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  16. Sexually transmitted infections-microbial infections, 2007 update.

    PubMed

    Waugh, Michael

    2007-01-01

    Human sexual behavior required for the continuation of humankind nevertheless has its downsides, among them sexually transmitted infections (STIs). The treatment of microbial STIs is challenging but not in itself essentially very difficult. Controlling STIs, on the other hand, is like the task of Sisyphus, a king in Greek mythology who was forced forever to roll a block of stone to the top of a steep hill, only to see it roll back to the valley, where he started the toilsome task again. This is how many a venereologist must view the day's practice, supervising patients with STIs. Yes, there are newcomers, many of them very young, but there are many others, the recidivists, whom the physician and health care staff know only too well. "You don't mind seeing me again, doc. You (collectively) were so good to me last time"--as though catching a chlamydial infection 3 or 4 times, gonorrhea 20 or 30 times, and syphilis on occasion were badges of virility or part of life's natural progression. This is the pattern of STIs in 2007. PMID:17786104

  17. Adolescents' Sexually Transmitted Disease Protective Attitudes Predict Sexually Transmitted Disease Acquisition in Early Adulthood

    ERIC Educational Resources Information Center

    Crosby, Richard A.; Danner, Fred

    2008-01-01

    Background: Estimates suggest that about 48% of nearly 19 million cases of sexually transmitted diseases (STDs) occurring annually in the United States are acquired by persons aged 15-24 years. The purpose of this study was to test the hypothesis that adolescents' attitudes about protecting themselves from STDs predict their laboratory-confirmed…

  18. Stochastic resonance in a nonlinear mechanical vibration isolation system

    NASA Astrophysics Data System (ADS)

    Lu, Zeqi; Chen, Li-Qun; Brennan, Michael J.; Yang, Tiejun; Ding, Hu; Liu, Zhigang

    2016-05-01

    This paper concerns the effect that a stochastic resonance can have on a vibration isolation system. Rather than reducing the transmitted force, it is shown that it is possible to significantly mask the component of the force transmitted though the isolator, when the system is excited harmonically. This can be achieved by adding a very low intensity of random noise to the harmonic excitation force. The nonlinear mechanical vibration isolation system used in the study consists of a vertical linear spring in parallel with two horizontal springs, which are configured so that the potential energy of the system has a double-well. Prior to the analytical and numerical study, an experiment to demonstrate stochastic resonance in a mechanical system is described.

  19. Effect of Vibrations on Transportation System

    NASA Astrophysics Data System (ADS)

    Birlik, Gülin; Sezgin, Önder Cem

    In overly populated cities people living in suburban areas have to endure long journeys in order to reach their job sites. Whether they go by train, bus or by car they are inevitably exposed to vibrations, of considerable magnitude, in vertical (z) and lateral (x, y) directions. The immediate effect of vibration exposure is the fatigue of ones' muscles. This is verified by the blood and saliva analysis of the volunteers travelling in a train. Their lactic acid levels were increased by 34% at the end of a 5 hr journey. The most affected people by vibration were, without doubt, the train operators and bus drivers. 42% of the suburban train operators had pain complaints at their waists. az(floor) in the machinist cabin of a suburban train was measured to be, on the average, 0.23 m/s2. Max peak was 1.34 m/s2. The bus and car drivers were exposed to lower vibrations but they were exposed to multiple shocks originating from the non-standardized humps placed on the roads. Peak az(seat) = 0.054 m/s2 (f = 5.25 Hz) (vcar = 30 km/hr) on an asphalt road increased considerably while crossing over a hump. This value was 1.27 m/s2 (f = 4.5 Hz) in case of bus drivers (vbus = 20 km/hr). Studies have been done to provide practical measures for the reduction of the vibrations transmitted to the drivers. The waist belts filled with fluids of different viscosities prepared for this purpose seemed to be promising. The cushions filled with glycerin and gel were observed to be the best alternatives.

  20. Back to basics: hand hygiene and surgical hand antisepsis.

    PubMed

    Spruce, Lisa

    2013-11-01

    Health care-associated infections (HAIs) are a significant issue in the United States and throughout the world, but following proper hand hygiene practices is the most effective and least expensive way to prevent HAIs. Hand hygiene is inexpensive and protects patients and health care personnel alike. The four general types of hand hygiene that should be performed in the perioperative environment are washing hands that are visibly soiled, hand hygiene using alcohol-based products, surgical hand scrubs, and surgical hand scrubs using an alcohol-based surgical hand rub product. Barriers to proper hand hygiene may include not thinking about it, forgetting, skin irritation, a lack of role models, or a lack of a safety culture. One strategy for improving hand hygiene practices is monitoring hand hygiene as part of a quality improvement project, but the most important aspect for perioperative team members is to set an example for other team members by following proper hand hygiene practices and reminding each other to perform hand hygiene. PMID:24209795

  1. Very high numerical aperture light transmitting device

    DOEpatents

    Allison, Stephen W.; Boatner, Lynn A.; Sales, Brian C.

    1998-01-01

    A new light-transmitting device using a SCIN glass core and a novel calcium sodium cladding has been developed. The very high index of refraction, radiation hardness, similar solubility for rare earths and similar melt and viscosity characteristics of core and cladding materials makes them attractive for several applications such as high-numerical-aperture optical fibers and specialty lenses. Optical fibers up to 60 m in length have been drawn, and several simple lenses have been designed, ground, and polished. Preliminary results on the ability to directly cast optical components of lead-indium phosphate glass are also discussed as well as the suitability of these glasses as a host medium for rare-earth ion lasers and amplifiers.

  2. Pension Participation: Do Parents Transmit Time Preference?

    PubMed Central

    Chiteji, Ngina; Stafford, Frank

    2013-01-01

    A wide range of economic and health behaviors are influenced by individuals’ attitudes toward the future – including investments in human capital, health capital and financial capital. Intergenerational correlations in such behaviors suggest an important role the family may play in transmitting time preferences to children. This article presents a model of parental investment in future-oriented capital, where parents shape their children’s time preference rates. The research identifies a dual role for a parent’s time preference rate in the process of shaping the offspring’s attitude toward the future, and discusses paths through which parents may socialize children to be patient. The model’s implications are studied by investigating the parent-child correlation in pension participation using data from the Panel Study of Income Dynamics PMID:23807825

  3. Development of 20 GHz monolithic transmit modules

    NASA Technical Reports Server (NTRS)

    Higgins, J. A.

    1988-01-01

    The history of the development of a transmit module for the band 17.7 to 20.2 GHz is presented. The module was to monolithically combine, on one chip, five bits of phase shift, a buffer amplifier and a power amplifier to produce 200 mW to the antenna element. The approach taken was MESFET ion implanted device technology. A common pinch-off voltage was decided upon for each application. The beginning of the total integration phases revealed hitherto unencountered hazards of large microwave circuit integration which were successfully overcome. Yield and customer considerations finally led to two separate chips, one containing the power amplifiers and the other containing the complete five bit phase shifter.

  4. Sexually Transmitted Diseases on Bipartite Graph

    NASA Astrophysics Data System (ADS)

    Wen, Luo-Sheng; Zhong, Jiang; Yang, Xiao-Fan

    2009-01-01

    We study the susceptible-infected-susceptible (SIS) epidemic model on bipartite graph. According to the difference of sex conception in western and oriental nations, we construct the Barabási Albert-Barabási Albert (BA-BA) model and Barabási-Albert Homogeneity (BA-HO) model for sexually transmitted diseases (STDs). Applying the rate equation approach, the positive equilibria of both models are given analytically. We find that the ratio between infected females and infected males is distinctly different in both models and the infected density in the BA-HO model is much less than that in the BA-BA model. These results explain that the countries with small ratio have less infected density than those with large ratio. Our numerical simulations verify these theoretical results.

  5. Confronting Ebola as a Sexually Transmitted Infection.

    PubMed

    Fischer, William A; Wohl, David A

    2016-05-15

    The unprecedented Ebola outbreak that devastated West Africa evolved within months from a regional outbreak to a global public health emergency. While the rate of confirmed cases declined dramatically, sporadic clusters of Ebola virus disease (EVD) continue well beyond the double incubation period of 42 days used to declare a nation Ebola-free. At the same time, evidence that the virus persists in genital fluids and can be sexually transmitted, along with the potential for lingering virus in other body compartments to permit recrudescence of EVD, has shaken our thinking of what it takes to achieve lasting control of an Ebola epidemic. A comprehensive response to the threat of persistence and sexual transmission of Ebola is required and should build on accessible longitudinal medical care of survivors and accurate genital fluid testing for Ebola. Control of this and future Ebola outbreaks will depend on our ability to recognize and respond to this persistence of the virus in those who survive. PMID:26936667

  6. High School Dropouts and Sexually Transmitted Infections

    PubMed Central

    Anderson, D. Mark; Pörtner, Claus C.

    2015-01-01

    People who drop out of high school fare worse in many aspects of life. We analyze the relationship between dropping out of high school and the probability of contracting a sexually transmitted infection (STI). Previous studies on the relationship between dropout status and sexual outcomes have not empirically addressed unobserved heterogeneity at the individual level. Using fixed effects estimators, we find evidence supporting a positive relationship between dropping out of high school and the risk of contracting an STI for females. Furthermore, we present evidence that illustrates differences between the romantic partners of dropouts versus enrolled students. These differences suggest that female dropouts may be more susceptible to contracting STIs because they partner with significantly different types of people than non-dropouts. Our results point to a previously undocumented benefit of encouraging those at risk of dropping out to stay in school longer. PMID:25705058

  7. Design, fabrication and testing of two electrohydraulic vibration isolation systems for helicopter environments

    NASA Technical Reports Server (NTRS)

    Allen, R. E.; Calcaterra, P. C.

    1972-01-01

    Two electrohydraulic vibration isolation systems were designed and fabricated to reduce the vertical vibrations transmitted to the XH-51N research helicopter cabin at the blade passage frequency (18 Hz) and its first harmonic (36 Hz). Hydraulic power and electrical control are provided to two separate servoactuators from a common power supply and control electronics package located behind the pilot's seat. One servoactuator is installed between the cabin and fuselage and replaces an existing passive spring. A second servoactuator is mounted between the existing seat and cabin floor. Both servoactuators incorporate a mechanical failsafe design. The control electronics circuitry provides automatic tracking of the blade passage frequency. Results of laboratory, environmental and ground vibration tests employing an XH-51A stripped down helicopter fuselage show that the active cabin isolator reduces the vertical vibrations transmitted from the fuselage attachment point to the cabin attachment point at 18 and 36 Hz (or as an alternative, 6 Hz) by better than 90 percent.

  8. [Anorectal manifestations of sexually transmitted infections].

    PubMed

    Lautenschlager, Stephan

    2013-07-01

    The incidence of sexually transmitted infections is rising in Europe and in Switzerland since the beginning of the third millenium. Many organisms may affect the perianal skin and the anorectum. While some of these infections are a result of contigous spread from genital infection, most result from receptive anal intercourse affecting males who have sex with males but is seen increasingly in females as well since there is evidence of the increasing popularity of anal sex among heterosexuals. The symptoms of specific infections are largely dependent on the route and site of inoculation. Organisms that cause typical genital symptoms - such as syphilis, chancroid, herpes simplex or HPV-infection - result in similar symptoms when the perianal skin, the anoderm or the distal anal canal are the site of infection. Patients with proctitis may have unspecific signs in various degrees including mucous discharge, rectal bleeding, anorectal pain, superficial ulcers and sometimes generalized lymphadenopathy and fever. It is of utmost importance to include STIs (e. g. lymphogranuloma venereum, gonorrhea, non-LGV-chlamydia and herpes simplex) in the differential diagnosis in these patients. Unfortunately rectal infection with chlamydia and gonorrhea is asymptomatic in the majority of cases of men having sex with men and in high-risk females. A careful history and physical examination is essential in establishing a correct diagnosis, usually supported by proctoscopy, culture, PCR, serology and histology. Certain organisms, more commonly thought of as food- or water-borne disease may be sexually transmitted by direct or indirect fecal-oral contact from various sexual practices. PMID:23798024

  9. Generalization of socially transmitted and instructed avoidance

    PubMed Central

    Cameron, Gemma; Schlund, Michael W.; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance—instructions and social observation—on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS−). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  10. Human anisakiasis transmitted by marine food products.

    PubMed

    Deardorff, T L; Kayes, S G; Fukumura, T

    1991-01-01

    Seafood-transmitted parasitic diseases represent an emerging area of interest to the U.S. Food and Drug Administration. Human infections with marine parasites are generally the result of ingesting uncooked seafood products. Over 50 species of helminthic parasites are known to infect humans worldwide. Recently, the number of infections with one of these helminths, the juvenile stage of the marine nematode, Anisakis simplex, has increased in the United States. Raw fish dishes such as lomi lomi salmon and sashimi are known to transmit the parasite to unsuspecting citizens and the most frequently implicated fish in the transmission of this zoonotic disease is the Pacific salmon (Oncorhynchus spp.). The risk of infection from fishes caught in Hawaiian waters is slight; however, a juvenile Anisakis simplex infected one patient from either locally caught aku or ahi. We report 4 new cases, which brings the total number of known cases in Hawaii to 7. Five of the 7 cases were diagnosed and treated by means of an endoscope and biopsy forceps. Serological profiles are presented in several of these cases. One case represents the first known instance of reinfection; the initial infection occurred 2 years prior. The second infection gave an opportunity to compare the human response to a challenge infection and to investigate the validity of the "double hit" theory. Increased awareness by physicians to the clinical features of this disease is warranted. The zoonotic disease, anisakiasis, should be considered in patients presenting with intense abdominal pain, if these patients admit they have recently eaten raw or undercooked seafoods. PMID:2022472

  11. Artificial dexterous hand

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    An artificial dexterous hand is provided for conformally engaging and manipulating objects. The hand includes an articulated digit which is connected to an engagement sub-assembly and has a first shape adaption mechanism associated with it. The digit has a digit base and first and second phalanges. The digit base is operatively interconnected to the first phalange by a base joint having a base pulley. The phalanges are operatively interconnected by a separate first phalange joint having a first phalange pulley. The engagement sub-assembly includes a tendon, which is received by the base pulley and by the first phalange pulley, and an actuation device for selectively tensioning the tendon. The first shape adaption mechanism is responsive to and receives the tendon. It is also situated between the base joint and the first phalange joint and is connected to the first phalange. Upon actuation by the actuation device, the phalanges are caused to pivot relative to the base joint and the second phalange is caused to pivot relative to the first phalange. At the same time, the first shape adaption mechanism controls the sequence of the aforementioned pivoting of the phalanges through application of braking force to the tendon.

  12. Vibration isolation of automotive vehicle engine using periodic mounting systems

    NASA Astrophysics Data System (ADS)

    Asiri, S.

    2005-05-01

    Customer awareness and sensitivity to noise and vibration levels have been raised through increasing television advertisement, in which the vehicle noise and vibration performance is used as the main market differentiation. This awareness has caused the transportation industry to regard noise and vibration as important criteria for improving market shares. One industry that tends to be in the forefront of the technology to reduce the levels of noise and vibration is the automobile industry. Hence, it is of practical interest to reduce the vibrations induced structural responses. The automotive vehicle engine is the main source of mechanical vibrations of automobiles. The engine is vulnerable to the dynamic action caused by engine disturbance force in various speed ranges. The vibrations of the automotive vehicle engines may cause structural failure, malfunction of other parts, or discomfort to passengers because of high level noise and vibrations. The mounts of the engines act as the transmission paths of the vibrations transmitted from the excitation sources to the body of the vehicle and passengers. Therefore, proper design and control of these mounts are essential to the attenuation of the vibration of platform structures. To improve vibration resistant capacities of engine mounting systems, vibration control techniques may be used. For instance, some passive and semi-active dissipation devices may be installed at mounts to enhance vibration energy absorbing capacity. In the proposed study, a radically different concept is presented whereby periodic mounts are considered because these mounts exhibit unique dynamic characteristics that make them act as mechanical filters for wave propagation. As a result, waves can propagate along the periodic mounts only within specific frequency bands called the "Pass Bands" and wave propagation is completely blocked within other frequency bands called the "Stop Bands". The experimental arrangements, including the design of

  13. Hand washing promotion for preventing diarrhoea

    PubMed Central

    Ejemot-Nwadiaro, Regina I; Ehiri, John E; Arikpo, Dachi; Meremikwu, Martin M; Critchley, Julia A

    2015-01-01

    -risk population showed significant reduction in mean episodes of diarrhoea (1.68 fewer) in the intervention group (Mean difference 1.68, 95% CI 1.93 to 1.43; one trial, 148 participants, moderate quality evidence). There was increase in hand washing frequency, seven times per day in the intervention group versus three times in the control in this hospital trial (one trial, 148 participants, moderate quality evidence). We found no trials evaluating or reporting the effects of hand washing promotions on diarrhoea-related deaths, all-cause-under five mortality, or costs. Authors' conclusions Hand washing promotion probably reduces diarrhoea episodes in both child day-care centres in high-income countries and among communities living in LMICs by about 30%. However, less is known about how to help people maintain hand washing habits in the longer term. PLAIN LANGUAGE SUMMARY Hand washing promotion for preventing diarrhoea Review question This Cochrane Review summarises trials evaluating the effects of promoting hand washing on the incidence of diarrhoea among children and adults in day-care centres, schools, communities, or hospitals. After searching for relevant trials up to 27 May 2015, we included 22 randomized controlled trials conducted in both high-income countries (HICs) and low- and middle-income countries (LMICs). These trials enrolled 69,309 children and 148 adults. How does hand washing prevent diarrhoea and how might hand washing be promoted Diarrhoea causes many deaths in children below five years of age, mostly in LMICs. The organisms causing diarrhoea are transmitted from person to person through food and water contaminated with faeces, or through person-to-person contact. Hand washing after defecation, or after cleaning a baby's bottom, and before preparing and eating food, can therefore reduce the risk of diarrhoea. Hand washing can be promoted through group or individual training on hygiene education, germ-health awareness, use of posters, leaflets, comic books

  14. Hands Up: Attentional Prioritization of Space Near the Hand

    ERIC Educational Resources Information Center

    Reed, Catherine L.; Grubb, Jefferson D.; Steele, Cleophus

    2006-01-01

    This study explored whether hand location affected spatial attention. The authors used a visual covert-orienting paradigm to examine whether spatial attention mechanisms--location prioritization and shifting attention--were supported by bimodal, hand-centered representations of space. Placing 1 hand next to a target location, participants detected…

  15. Electrorheological vibration system

    NASA Astrophysics Data System (ADS)

    Korobko, Evguenia V.; Shulman, Zinovy P.; Korobko, Yulia O.

    2001-07-01

    The present paper is devoted to de3velopment and testing of an active vibration system. The system is intended for providing efficient motion of a piston in a hydraulic channel for creation of shocks and periodic vibrations in a low frequency range by means of the ER-valves based on an electrosensitive working me dium, i.e. electrorheological fluids. The latter manifests the electrorheological (ER) effect, i.e. a reversible change in the rheological characteristics of weak-conducting disperse compositions in the presence of constant and alternating electric fields. As a result of the experimental study of the dependence of viscoelastic properties of the ER-fluid on the magnitude and type of an electric field, the optimum dimensions of the vibrator and the its valves characteristics of the optimal electrical signal are determined. For control of an ER- vibrator having several valves we have designed a special type of a high-voltage two-channel impulse generator. Experiments were conducted at the frequencies ranged from 1- 10 Hz. It has been shown, that a peak force made 70% of the static force exercised by the vibrator rod. A phase shift between the input voltage and the load acceleration was less than 45 degree(s)C which allowed servocontrol and use of the vibrator for attendant operations. It was noted that a response of the vibrator to a stepwise signal has a delay only of several milliseconds.

  16. Triboelectric Nanogenerator as a Self-Powered Communication Unit for Processing and Transmitting Information.

    PubMed

    Yu, Aifang; Chen, Xiangyu; Wang, Rui; Liu, Jingyu; Luo, Jianjun; Chen, Libo; Zhang, Yang; Wu, Wei; Liu, Caihong; Yuan, Hongtao; Peng, Mingzeng; Hu, Weiguo; Zhai, Junyi; Wang, Zhong Lin

    2016-04-26

    In this paper, we demonstrate an application of a triboelectric nanogenerator (TENG) as a self-powered communication unit. An elaborately designed TENG is used to translate a series of environmental triggering signals into binary digital signals and drives an electronic-optical device to transmit binary digital data in real-time without an external power supply. The elaborately designed TENG is built in a membrane structure that can effectively drive the electronic-optical device in a bandwidth from 1.30 to 1.65 kHz. Two typical communication modes (amplitude-shift keying and frequency-shift keying) are realized through the resonant response of TENG to different frequencies, and two digital signals, i.e., "1001" and "0110", are successfully transmitted and received through this system, respectively. Hence, in this study, a simple but efficient method for directly transmitting ambient vibration to the receiver as a digital signal is established using an elaborately designed TENG and an optical communication technique. This type of the communication system, as well as the implementation method presented, exhibits great potential for applications in the smart city, smart home, password authentication, and so on. PMID:26962878

  17. Organ pipe resonance induced vibration in piping system

    SciTech Connect

    Wang, T.

    1996-12-01

    Acoustic-induced vibration is a fluid-structure interaction phenomenon. The feedback mechanism between the acoustic pressure pulsation and the structure movements determines the excited acoustic modes which, in turn, amplify the structure response when confidence frequency and mode shape matching occurs. The acoustic modes are not determined from the acoustic boundary conditions alone, structure feedback is as responsible for determining the acoustic modes and shaping the resulting forcing functions. Acoustic-induced piping vibration, when excited, does not attenuate much with distance. Pressure pulsation can be transmitted throughout the piping system and its branch connections. It is this property that makes vibration monitoring difficult, because vibration can surface at locations far away from the acoustic source when resonance occurs. For a large piping system with interconnected branches, the monitoring task can be formidable, particularly when there is no indication what the real source is. In organ pipe resonance induced vibration, the initiating acoustic source may be inconspicuous or unavoidable during operation. In these situations, the forcing function approach can offer an optimal tool for vibration assessment. The forcing function approach was used in the evaluation of a standby steam piping vibration problem. Monitoring locations and instrument specifications were determined from the acoustic eigenfunction profiles. Measured data confirmed the presence of coherent vibrations in the large bore piping. The developed forcing function permits design evaluation of the piping system, which leads to remedial actions and enables fatigue life determination, thus providing confidence to system operation. The forcing function approach is shown to be useful in finding potential vibration area and verifying the integrity of weak structure links. Application is to steam lines at BWR plants.

  18. Compact artificial hand

    NASA Technical Reports Server (NTRS)

    Wiker, G. A.; Mann, W. A. (Inventor)

    1979-01-01

    A relatively simple, compact artificial hand, is described which includes hooks pivotally mounted on first frame to move together and apart. The first frame is rotatably mounted on a second frame to enable "turning at the wrist" movement without limitation. The second frame is pivotally mounted on a third frame to permit 'flexing at the wrist' movement. A hook-driving motor is fixed to the second frame but has a shaft that drives a speed reducer on the first frame which, in turn, drives the hooks. A second motor mounted on the second frame, turns a gear on the first frame to rotate the first frame and the hooks thereon. A third motor mounted on the third frame, turns a gear on a second frame to pivot it.

  19. Metalworking fluid hand dermatitis.

    PubMed

    Ueno, Saori; Shiomi, Yuko; Yokota, Kozo

    2002-07-01

    In a household appliance plant, several rinse-free lubricating fluids have been used instead of neat mineral oils since 1994: mixtures of isoparaffinic hydrocarbons with 9 to 14 carbons per molecule. As such they denature keratin, irritate and defat the skin, and remove water from it. Work gloves have been worn over plastic gloves and separate, reusable, cotton inner gloves have been added to absorb sweat since skin problems were first recognized in 1994. All 74 males (mean +/- SD, 38.8 +/- 8.0 years) who work with the fluids were interviewed and given cutaneous examinations when indicated. While 4 cases of severe dermatitis and 31 cases of mild dermatitis were identified, 28 individuals gave a history of similar problems since the use of lubricating fluids. Their symptoms were typical of primary skin irritation. The hands were the commonly affected region (63 of 63 cases: 100%), followed by the thighs (15.9%) and trunk (11.1%). The work-related skin symptoms identified were less common in workers who immediately removed the liquid with soap and water, when it is spilled on the hands, than in those who did not, but the difference was not statistically significant (7/23 (30.4%) vs. 28/51 (54.9%), p=0.051 by chi-square test). Since skin contact with metalworking fluids (MWF) is often unavoidable, good personal hygiene is important in minimizing potential adverse health effects. Health education thus remains the most important preventive measure against irritant contact dermatitis among workers handling MWFs. PMID:12141380

  20. Hand-foot-mouth disease

    MedlinePlus

    Hand-foot-mouth disease is a common viral infection that most often begins in the throat. ... Hand-foot-mouth disease (HFMD) is most commonly caused by a virus called coxsackievirus A16. Children under age 10 are most ...

  1. Hand-foot-mouth disease

    MedlinePlus

    ... medlineplus.gov/ency/article/000965.htm Hand-foot-mouth disease To use the sharing features on this page, please enable JavaScript. Hand-foot-mouth disease is a common viral infection that most ...

  2. Fundamentals of IC engine torsional vibration

    SciTech Connect

    Doughty, S.

    1988-01-01

    Fluctuations in IC engine cylinder pressure are an obvious source of torsional vibration excitation, although the details of the coupling from cylinder pressure to torque on the crankshaft are complicated. A second, less obvious source of torsional excitation is the effect of variable inertia associated with the engine slider-crank mechanism. This is a tutorial paper, intended to show the relation between, on the one hand, the actual engine slider-crank mechanism subject to combustion gas pressure and, on the other hand, the models commonly used for torsional vibration analysis that involve constant inertias subject to torques expressed by Fourier series. As such, it uses some new approaches to reach previously known results with a greater degree of physical insight. The presentation is in terms of a single cylinder, two stroke engine with load, and makes clear the roles of piston mass, connecting rod mass and moment of inertia, and crank inertia as they affect both the effective inertia and the effective torque. The determination of natural frequencies and the forced vibration response calculation are briefly described to complete the analysis. The development of a Fourier series representation for the effective torque, including both the cylinder pressure and inertia variation is also discussed. The various components for the response are identified, in an effort to clarify the meaning of terms such as ''zero frequency mode,'' ''rigid body mode,'' and ''twisting mode.''

  3. Vibration exposure and prevention in Finland.

    PubMed

    Starck, J; Pyykkö, I; Koskimies, K; Pekkarinen, J

    1994-05-01

    The number of annually compensated occupational diseases due to exposure to hand-arm vibration (HAV) has decreased during the last 15 years. The number of exposed workers has been declining in Finland, especially in forestry work, as harvesters have increasingly replaced manual chain saw operations. During the entire 1970s, forest work caused more cases of vibration-induced occupational diseases than all industrial branches together. The decrease is mainly due to the technical development of chain saws, but also to the effective health care services in Finland. Other factors such as warm transport, warm rest cabins in which to take pauses at work, warm meals, adequate protective clothing, and vocationally adjusted early medical rehabilitation have helped to cut down health hazards, especially in forest work. The number of new cases has been decreasing in Finland not only in forestry but also in other industries. In Finland a considerable amount of research has been conducted to hand-arm vibration, resulting in the increased awareness of the health risks related to certain occupations. This has helped to carry out the Primary Health Care Act (1972) followed by the Occupational Health Care Act (1979) which obligates employers to arrange occupational health care for their employees. We believe that the research activity has contributed significantly to achieving the present health in Finnish work places. The purpose of the present paper is to describe the cases of occupational exposure to HAV, and the effectiveness of different preventive measures in Finland. PMID:7708103

  4. Soil transmitted parasites in Qualyobia Governorate.

    PubMed

    El Fakahany, Amany F; Younis, Mohamed S; Ali, Ali El-Said; El-Ghareeb, Azza S; Omar, Rabab El Sayed

    2013-08-01

    The study determined the relation between prevalence of intestinal parasites and soil-transmitted parasites among households in Shiblanga representing a rural area of Qualyobia Governorate and Benha City representing an urban area of the same Governorate. The effect of soil's type on the intensity of parasites and to provide guidance on the prevention and control of soil transmitted parasitic infections for future studies in this field. This study was conducted at Benha City and Shiblanga village representing the urban and rural areas of Qualyobia Governorate. Geoparasites were investigated in-doors, around houses, in the fields and the streets from both areas. One hundred soil samples from Benha city and one hundred soil samples from Shiblanga village were collected .each hundred soil samples was collected in the form of: 25 samples from the fields, 25 samples in-indoor yards, 25 samples the streets, 25 samples around houses. Approximately 200 g soil was collected in plastic bags at 2-10 cm depth from different parts. Stool samples from households in same areas were collected after taken oral consent. All soil samples were screened for parasites using different parasitological methods (Zinc sulphate flotation, ether sédimentation technique, modified Baerman's apparatus and modified Berlese technique). All stool samples were examined using direct smear, formalinether concentration techniques for detection of helminthes eggs, and modified acid-fast staining for detection of protozoa. The results showed that 86/200 soil samples were contaminated with different parasites, the prevalence rate of 43%. Soil samples from Shiblanga village showed higher level of parasitic contamination (56%) and Benha city showed a lower level of contamination by different parasites (30%). Soil samples obtained from Manshiet El-Nour district, Benha revealed the highest level of parasitic contamination. While, in Shiblanga, El-Mansheya district revealed the highest level of parasitic

  5. Altered Vision Near the Hands

    ERIC Educational Resources Information Center

    Abrams, Richard A.; Davoli, Christopher C.; Du, Feng; Knapp, William H., III; Paull, Daniel

    2008-01-01

    The present study explored the manner in which hand position may affect visual processing. We studied three classic visual attention tasks (visual search, inhibition of return, and attentional blink) during which the participants held their hands either near the stimulus display, or far from the display. Remarkably, the hands altered visual…

  6. Hand Hygiene: When and How

    MedlinePlus

    ... SOILED Duration of the entire procedure: 20-30 seconds WASH HANDS WHEN VISIBLY SOILED! OTHERWISE, USE HANDRUB Duration of the entire procedure: 40-60 seconds 1 a 1 b 2 012 Apply a palmful of the product in a cupped hand, covering all surfaces; Rub hands palm to palm; ...

  7. Whole-body vibration exercise in postmenopausal osteoporosis

    PubMed Central

    Mieszkowski, Jan; Niespodziński, Bartłomiej; Ciechanowska, Katarzyna

    2015-01-01

    The report of the World Health Organization (WHO) of 2008 defines osteoporosis as a disease characterized by low bone mass and an increased risk of fracture. Postmenopausal osteoporosis is connected to the decrease in estrogens concentration as a result of malfunction of endocrine ovarian function. Low estrogens concentration causes increase in bone demineralization and results in osteoporosis. Physical activity, as a component of therapy of patients with osteoporosis, has been used for a long time now. One of the forms of safe physical activity is the vibration training. Training is to maintain a static position or execution of specific exercises involving the appropriate muscles on a vibrating platform, the mechanical vibrations are transmitted to the body of the patient. According to the piezoelectric theory, pressure induces bone formation in the electrical potential difference, which acts as a stimulant of the process of bone formation. Whole body vibration increases the level of growth hormone and testosterone in serum, preventing sarcopenia and osteoporosis. The aim of this study was to review the literature on vibration exercise in patients with postmenopausal osteoporosis based on the PubMed and Medline database. While searching the database, the following key words were used ‘postmenopausal osteoporosis’ and ‘whole-body vibration exercise’. PMID:26327887

  8. Vibration Response of Multi Storey Building Using Finite Element Modelling

    NASA Astrophysics Data System (ADS)

    Chik, T. N. T.; Zakaria, M. F.; Remali, M. A.; Yusoff, N. A.

    2016-07-01

    Interaction between building, type of foundation and the geotechnical parameter of ground may trigger a significant effect on the building. In general, stiffer foundations resulted in higher natural frequencies of the building-soil system and higher input frequencies are often associated with other ground. Usually, vibrations transmitted to the buildings by ground borne are often noticeable and can be felt. It might affect the building and become worse if the vibration level is not controlled. UTHM building is prone to the ground borne vibration due to closed distance from the main road, and the construction activities adjacent to the buildings. This paper investigates the natural frequency and vibration mode of multi storey office building with the presence of foundation system and comparison between both systems. Finite element modelling (FEM) package software of LUSAS is used to perform the vibration analysis of the building. The building is modelled based on the original plan with the foundation system on the structure model. The FEM results indicated that the structure which modelled with rigid base have high natural frequency compare to the structure with foundation system. These maybe due to soil structure interaction and also the damping of the system which related to the amount of energy dissipated through the foundation soil. Thus, this paper suggested that modelling with soil is necessary to demonstrate the soil influence towards vibration response to the structure.

  9. PREFACE: Vibrations at surfaces Vibrations at surfaces

    NASA Astrophysics Data System (ADS)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  10. Damping Vibration at an Impeller

    NASA Technical Reports Server (NTRS)

    Hager, J. A.; Rowan, B. F.

    1982-01-01

    Vibration of pump shaft is damped at impeller--where vibration-induced deflections are greatest--by shroud and seal. Damping reduces vibrational motion of shaft at bearings and load shaft places on them. Flow through clearance channel absorbs vibration energy.

  11. NIF Ambient Vibration Measurements

    SciTech Connect

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  12. Secure Wireless Communications via Cooperative Transmitting

    PubMed Central

    Stojanovski, Toni Draganov; Marina, Ninoslav

    2014-01-01

    Information-theoretic secrecy is combined with cryptographic secrecy to create a secret-key exchange protocol for wireless networks. A network of transmitters, which already have cryptographically secured channels between them, cooperate to exchange a secret key with a new receiver at a random location, in the presence of passive eavesdroppers at unknown locations. Two spatial point processes, homogeneous Poisson process and independent uniformly distributed points, are used for the spatial distributions of transmitters and eavesdroppers. We analyse the impact of the number of cooperating transmitters and the number of eavesdroppers on the area fraction where secure communication is possible. Upper bounds on the probability of existence of positive secrecy between the cooperating transmitters and the receiver are derived. The closeness of the upper bounds to the real value is then estimated by means of numerical simulations. Simulations also indicate that a deterministic spatial distribution for the transmitters, for example, hexagonal and square lattices, increases the probability of existence of positive secrecy capacity compared to the random spatial distributions. For the same number of friendly nodes, cooperative transmitting provides a dramatically larger secrecy region than cooperative jamming and cooperative relaying. PMID:24711735

  13. Molecular Diagnostics for Soil-Transmitted Helminths

    PubMed Central

    O'Connell, Elise M.; Nutman, Thomas B.

    2016-01-01

    Historically, the diagnosis of soil-transmitted helminths (STHs) (e.g., Strongyloides stercoralis, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and Ascaris lumbricoides) has relied on often-insensitive microscopy techniques. Over the past several years, there has been an effort to use molecular diagnostics, particularly quantitative polymerase chain reaction (qPCR), to detect intestinal pathogens. While some platforms have been approved by regulatory bodies (e.g., Food and Drug Administration) to detect intestinal bacteria, viruses, and protozoa, there are no approved tests currently available for STH. Although studies comparing qPCR to microscopy methods for STH are imperfect, due in large part to a lack of a sufficient gold standard, they do show a significant increase in sensitivity and specificity of qPCR compared with microscopic techniques. These studies, as well as the advantages and disadvantages of using qPCR for STH diagnosis, are discussed. Guidelines for those designing future studies utilizing qPCR are proposed for optimizing results, as is the proposition for using standardized molecular diagnostics routinely for STH in clinical laboratories and for field-based studies when possible. PMID:27481053

  14. Secure wireless communications via cooperative transmitting.

    PubMed

    Stojanovski, Toni Draganov; Marina, Ninoslav

    2014-01-01

    Information-theoretic secrecy is combined with cryptographic secrecy to create a secret-key exchange protocol for wireless networks. A network of transmitters, which already have cryptographically secured channels between them, cooperate to exchange a secret key with a new receiver at a random location, in the presence of passive eavesdroppers at unknown locations. Two spatial point processes, homogeneous Poisson process and independent uniformly distributed points, are used for the spatial distributions of transmitters and eavesdroppers. We analyse the impact of the number of cooperating transmitters and the number of eavesdroppers on the area fraction where secure communication is possible. Upper bounds on the probability of existence of positive secrecy between the cooperating transmitters and the receiver are derived. The closeness of the upper bounds to the real value is then estimated by means of numerical simulations. Simulations also indicate that a deterministic spatial distribution for the transmitters, for example, hexagonal and square lattices, increases the probability of existence of positive secrecy capacity compared to the random spatial distributions. For the same number of friendly nodes, cooperative transmitting provides a dramatically larger secrecy region than cooperative jamming and cooperative relaying. PMID:24711735

  15. Sexually transmitted infections and older adults.

    PubMed

    Johnson, Beverly K

    2013-11-01

    Older adults continue to be sexually active in their later years. A range of sexually transmitted infections (STIs) such as chlamydia, gonorrhea, syphilis, and HIV have been reported among older adults. Risk factors for STIs in older populations include (a) normal sexual changes associated with aging (e.g., increased time to attain an erection, decreased vaginal lubrication, decreases in sexual hormones); (b) psychosocial changes (e.g., loss of partner or spouse and re-entering the dating scene); and (c) risky sexual behaviors, including no or infrequent use of condoms. Screening of adults for STIs should occur regardless of age based on guidelines such as those from the Centers for Disease Control and Prevention and the U.S. Preventive Services Task Force. As discussed in this article, nurses can use assessment guides and engage in interventions such as counseling and education with older adults to reduce STI risk or refer for treatment. Numerous online resources exist for both nurses and older adults to increase knowledge of STIs. PMID:24066789

  16. Travel-related sexually transmitted infections.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz

    2015-01-01

    Sexually transmitted infections (STIs) are among the most common notifiable health problems worldwide, with particularly high rates in developing countries. Men and women with multiple sexual partners at home or a previous history of STIs are more likely to have casual sexual exposure (CSE) while travelling. Over the last several decades 5% to even 50% of short-term travellers engaged in CSE during foreign trips. It is estimated that only 50% of travellers use condoms during casual sex abroad. Sexual contact with commercial sex workers is an exceptionally high-risk behaviour. The common risk factor is also young age. Adolescents and young adults constitute 25% of the sexually active population, but represent almost 50% of all new acquired STIs. Many STIs are asymptomatic and therefore can be difficult to identify and control. The clinical manifestation of STIs can be grouped into a number of syndromes, such as genital ulcer or erosion, urethral or vaginal discharge, pelvic inflammatory disease. STIs are divided into curable infections caused by bacteria (gonorrhoea, chlamydiasis, syphilis, chancroid, lymphogranuloma venereum, granuloma inguinale) or protozoa (trichomoniasis) and incurable viral infections (genital herpes, genital warts, HIV). STIs are not only a cause of acute morbidity, but may result in complications including male and female infertility, ectopic pregnancy, cervical cancer, premature mortality or miscarriage. Monogamous sex with a stable, uninfected partner or sexual abstinence remains the only way to avoid the risk of becoming infected with STIs. PMID:26726895

  17. Molecular Diagnostics for Soil-Transmitted Helminths.

    PubMed

    O'Connell, Elise M; Nutman, Thomas B

    2016-09-01

    Historically, the diagnosis of soil-transmitted helminths (STHs) (e.g., Strongyloides stercoralis, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and Ascaris lumbricoides) has relied on often-insensitive microscopy techniques. Over the past several years, there has been an effort to use molecular diagnostics, particularly quantitative polymerase chain reaction (qPCR), to detect intestinal pathogens. While some platforms have been approved by regulatory bodies (e.g., Food and Drug Administration) to detect intestinal bacteria, viruses, and protozoa, there are no approved tests currently available for STH. Although studies comparing qPCR to microscopy methods for STH are imperfect, due in large part to a lack of a sufficient gold standard, they do show a significant increase in sensitivity and specificity of qPCR compared with microscopic techniques. These studies, as well as the advantages and disadvantages of using qPCR for STH diagnosis, are discussed. Guidelines for those designing future studies utilizing qPCR are proposed for optimizing results, as is the proposition for using standardized molecular diagnostics routinely for STH in clinical laboratories and for field-based studies when possible. PMID:27481053

  18. A Quantitative Assessment Method for Ascaris Eggs on Hands

    PubMed Central

    Jeandron, Aurelie; Ensink, Jeroen H. J.; Thamsborg, Stig M.; Dalsgaard, Anders; Sengupta, Mita E.

    2014-01-01

    The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness. PMID:24802859

  19. Spatiotemporal interactions between audition and touch depend on hand posture.

    PubMed

    Sanabria, Daniel; Soto-Faraco, Salvador; Spence, Charles

    2005-09-01

    We report two experiments designed to assess the consequences of posture change on audiotactile spatiotemporal interactions. In Experiment 1, participants had to discriminate the direction of an auditory stream (consisting of the sequential presentation of two tones from different spatial positions) while attempting to ignore a task-irrelevant tactile stream (consisting of the sequential presentation of two vibrations, one to each of the participant's hands). The tactile stream presented to the participants' hands was either spatiotemporally congruent or incongruent with respect to the sounds. A significant decrease in performance in incongruent trials compared with congruent trials was demonstrated when the participants adopted an uncrossed-hands posture but not when their hands were crossed over the midline. In Experiment 2, we investigated the ability of participants to discriminate the direction of two sequentially presented tactile stimuli (one presented to each hand) as a function of the presence of congruent vs incongruent auditory distractors. Here, the crossmodal effect was stronger in the crossed-hands posture than in the uncrossed-hands posture. These results demonstrate the reciprocal nature of audiotactile interactions in spatiotemporal processing, and highlight the important role played by body posture in modulating such crossmodal interactions. PMID:15942735

  20. 2008 Vibrational Spectroscopy

    SciTech Connect

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  1. Computer control by hand gestures

    NASA Astrophysics Data System (ADS)

    Jemel, Intidhar; Ejbali, Ridha; Zaied, Mourad

    2015-12-01

    This work fits into the context of the interpretation of automatic gestures based on computer vision. The aim of our work is to transform a conventional screen in a surface that allows the user to use his hands as pointing devices. These can be summarized in three main steps. Hand detection in a video, monitoring detected hands and conversion paths made by the hands to computer commands. To realize this application, it is necessary to detect the hand to follow. A classification phase is essential, at the control part. For this reason, we resorted to the use of a neuro-fuzzy classifier for classification and a pattern matching method for detection.

  2. HandsFree TLCMS

    Energy Science and Technology Software Center (ESTSC)

    2004-07-30

    The HandsFreeTLCMS software is able to - control an x,y,z stage connected to the computer via USB interface - automatically form and maintain the liquid junction between a TLC plate and the sampling probe of a TLC/MS surface sampler unit - automatically accomplish multiple-lane scans over a TLC plate making able to sample the whole surface by a pre-defined, reproducible, automated method - analyze mass spectrometric data collected during the surface scans and make datafilesmore » those contain x,y coordinates of surface spots (collected during the surface scans) and the corresponding mass signal intensities (integrated over a pre-defined m/z range) at those spots to produce 3-dimensional plots later in external graphic programs. - produce and save greyscale or color 2D pictures where X and Y axises of the picture correspond to the horizontal (x) and vertical (y) range of the scanned surface area and the color of a pixel is determined by the corresponding mass signal intensities (integrated over a pre-defined m/z range) at that X,Y spot« less

  3. Prosthetic helping hand

    NASA Technical Reports Server (NTRS)

    Vest, Thomas W. (Inventor); Carden, James R. (Inventor); Norton, William E. (Inventor); Belcher, Jewell G. (Inventor)

    1992-01-01

    A prosthetic device for below-the-elbow amputees, having a C-shaped clamping mechanism for grasping cylindrical objects, is described. The clamping mechanism is pivotally mounted to a cuff that fits on the amputee's lower arm. The present invention is utilized by placing an arm that has been amputated below the elbow into the cuff. The clamping mechanism then serves as a hand whenever it becomes necessary for the amputee to grasp a cylindrical object such as a handle, a bar, a rod, etc. To grasp the cylindrical object, the object is jammed against the opening in the C-shaped spring, causing the spring to open, the object to pass to the center of the spring, and the spring to snap shut behind the object. Various sizes of clamping mechanisms can be provided and easily interchanged to accommodate a variety of diameters. With the extension that pivots and rotates, the clamping mechanism can be used in a variety of orientations. Thus, this invention provides the amputee with a clamping mechanism that can be used to perform a number of tasks.

  4. HandsFree TLCMS

    SciTech Connect

    2004-07-30

    The HandsFreeTLCMS software is able to - control an x,y,z stage connected to the computer via USB interface - automatically form and maintain the liquid junction between a TLC plate and the sampling probe of a TLC/MS surface sampler unit - automatically accomplish multiple-lane scans over a TLC plate making able to sample the whole surface by a pre-defined, reproducible, automated method - analyze mass spectrometric data collected during the surface scans and make datafiles those contain x,y coordinates of surface spots (collected during the surface scans) and the corresponding mass signal intensities (integrated over a pre-defined m/z range) at those spots to produce 3-dimensional plots later in external graphic programs. - produce and save greyscale or color 2D pictures where X and Y axises of the picture correspond to the horizontal (x) and vertical (y) range of the scanned surface area and the color of a pixel is determined by the corresponding mass signal intensities (integrated over a pre-defined m/z range) at that X,Y spot

  5. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of

  6. Adsorption to fish sperm of vertically transmitted fish viruses

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.

    1984-01-01

    More than 99 percent of a vertically transmitted fish rhabdovirus, infectious hematopoietic necrosis virus, was removed from suspension in less than 1 minute by adsorption to the surface membrane of sperm from two genera of salmonid fishes. The vertically transmitted, infectious pancreatic necrosis virus adsorbed to a lesser degree, but no adsorption occurred with a second fish rhabdovirus that is not vertically transmitted. Such adsorption may be involved in vertical transmission of these viruses.

  7. Robotically enhanced rubber hand illusion.

    PubMed

    Arata, Jumpei; Hattori, Masashi; Ichikawa, Shohei; Sakaguchi, Masamichi

    2014-01-01

    The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics. PMID:25532152

  8. The use of a bend singlemode-multimode-singlemode (SMS) fibre structure for vibration sensing

    NASA Astrophysics Data System (ADS)

    Wu, Qiang; Yang, Minwei; Yuan, Jinhui; Chan, Hau Ping; Ma, Youqiao; Semenova, Yuliya; Wang, Pengfei; Yu, Chongxiu; Farrell, Gerald

    2014-11-01

    A bend singlemode-multimode-singlemode (SMS) fibre structure based vibration sensor is proposed and developed. This sensor configuration is very simple and employs a bend SMS fibre structure and a broadband optical source. The vibration applied to the bend SMS fibre structure will change the bend radius and hence the intensity of the transmitted optical power will also vary. Experimental results show that the sensor can detect both vibration frequencies and amplitudes over a broad range with good sensitivity, from a hertz to 12 kHz.

  9. Transmission of Force Sensations by Hand of Multi-DOF Master-Slave Robot Using Tendon-Driven Mechanism

    NASA Astrophysics Data System (ADS)

    Nozaki, Takahiro; Suzuki, Yusuke; Ohnishi, Kouhei

    In this study, a bilateral control system for tendon-driven robots is proposed. The rotation angle and torque of the robot joints are controlled by the proposed control system. In addition, a tendon-driven robot hand for haptic applications is developed. The proposed control system is employed by the robot hand to transmit force sensations.

  10. Spectroscopy and reactions of vibrationally excited transient molecules

    SciTech Connect

    Dai, H.L.

    1993-12-01

    Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

  11. Force Limited Vibration Testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry; Chang, Kurng Y.

    2005-01-01

    This slide presentation reviews the concept and applications of Force Limited Vibration Testing. The goal of vibration testing of aerospace hardware is to identify problems that would result in flight failures. The commonly used aerospace vibration tests uses artificially high shaker forces and responses at the resonance frequencies of the test item. It has become common to limit the acceleration responses in the test to those predicted for the flight. This requires an analysis of the acceleration response, and requires placing accelerometers on the test item. With the advent of piezoelectric gages it has become possible to improve vibration testing. The basic equations have are reviewed. Force limits are analogous and complementary to the acceleration specifications used in conventional vibration testing. Just as the acceleration specification is the frequency spectrum envelope of the in-flight acceleration at the interface between the test item and flight mounting structure, the force limit is the envelope of the in-flight force at the interface . In force limited vibration tests, both the acceleration and force specifications are needed, and the force specification is generally based on and proportional to the acceleration specification. Therefore, force limiting does not compensate for errors in the development of the acceleration specification, e.g., too much conservatism or the lack thereof. These errors will carry over into the force specification. Since in-flight vibratory force data are scarce, force limits are often derived from coupled system analyses and impedance information obtained from measurements or finite element models (FEM). Fortunately, data on the interface forces between systems and components are now available from system acoustic and vibration tests of development test models and from a few flight experiments. Semi-empirical methods of predicting force limits are currently being developed on the basis of the limited flight and system test

  12. Degree of Polarization at Simultaneous Transmit: Theoretical Aspects

    SciTech Connect

    Galletti M.; Zrnic, D. S.

    2012-05-01

    We consider weather radar measurements at simultaneous transmission and simultaneous reception of horizontal and vertical polarizations and show that the degree of polarization at simultaneous transmit (p{sub s}) is related to differential reflectivity and copolar correlation coefficient at simultaneous transmit (namely, Z{sub DR}s and {rho}{sub hy}s). We evaluate the potential of degree of polarization at simultaneous transmit for weather radar applications. Ultimately, we explore the consequences of adjusting the transmit polarization state of dual-polarization weather radars to circular polarization.

  13. Transfusion-transmitted infections in haemophilia patients.

    PubMed

    Zhubi, Bukurije; Mekaj, Ymer; Baruti, Zana; Bunjaku, Ilirijane; Belegu, Mazllum

    2009-11-01

    One of the largest therapeutic problem during the continuous treatment of the patients with Hemophilia A and B, are viral infections as Hepatitis B and C, and HIV, and the other infective diseases, which can be transmitted by the transfusion of blood products. The aim of this study is to analyze the complications of the hemophiliacs in Kosovo which have been treated with fresh frozen plasma, cryoprecipitate and concentrated products of FVIII and FIX. We have tested 75 patients with hemophilia A or B and there were used enzyme immunoassay test-Elisa method for the following: anti-HCV, HBsAg, HIV and TPHA.The serological data showed that HCV infection was positive in 29 cases or 38,7%, whereas infection with HBV and HIV were present in a smaller percentage of the patients (2,7% HBV and 1,4% for HIV). HCV infection was present only in 9,5% of the cases of the age group under 18 years. Infected hemophiliacs with one or two infective agents were found in 34,7%, respectively 4%. Infection with T. pallidum was present at none of the examined patients with hemophilia. HCV infection was higher in severe forms of hemophilia B (44,4%), compared with severe form of hemophilia A (30%).Based on our results, despite the infrequent application of FVIII and FIX concentrates, and other anti hemophilic preparations used in treating hemophilia patients, the number of infected hemophiliacs with blood-transmittable infectious agents was substantially high, especially with hepatitis C virus. PMID:20001991

  14. Complex noninvasive spectrophotometry in examination of patients with vibration disease

    NASA Astrophysics Data System (ADS)

    Tchernyi, V. V.; Rogatkin, D. A.; Gorenkov, R. V.; Karpov, V. N.; Shumskiy, V. I.; Lubchenko, P. N.

    2006-02-01

    A lot of industry workers all over the world have dealings with a strong mechanical vibration as with daily technology processes. Very often such long-time professional vibration causes the so-called professional "vibration disease", in English literature "white fingers syndrome", caused by a local vibration of hands. Among different clinical features of the vibration disease a leader's part of them consists of different cardiovascular and trophic disorders of tissues. The objects of the present study were the peripheral blood microcirculation, peripheral blood oxygenation and tissues hypoxia state in a finger skin under vibration disease. For this purpose we have used a combined noninvasive spectrophotometry diagnostic technique consisting of Laser-Doppler Flowmetry (LDF), Laser Fluorescent Diagnostics (LFD) and Tissues Reflectance Oximetry (TRO). The results show good possibilities of all mentioned above diagnostic methods in estimation of different vascular disorders. A good correlation between persistent microcirculation disorders and trophic disturbances revealed in tissues of distal ends of upper extremities of the patients with vibration disease was estimated. Additionally, in present study with the use of real and long-time TRO and LDF methods a good correlation between LDF and TRO data including correlation in detected rhythms of blood microcirculation was estimated as well.

  15. Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging

    NASA Astrophysics Data System (ADS)

    Hu, Zhengyi; Welch, Ian; Yuan, Xunhua; Pollmann, Steven I.; Nikolov, Hristo N.; Holdsworth, David W.

    2015-08-01

    Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as  ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice.

  16. Efficacy of Instant Hand Sanitizers against Foodborne Pathogens Compared with Hand Washing with Soap and Water in Food Preparation Settings: A Systematic Review.

    PubMed

    Foddai, Antonio C G; Grant, Irene R; Dean, Moira

    2016-06-01

    Hands can be a vector for transmitting pathogenic microorganisms to foodstuffs and drinks, and to the mouths of susceptible hosts. Hand washing is the primary barrier to prevent transmission of enteric pathogens via cross-contamination from infected persons. Conventional hand washing involves the use of water, soap, and friction to remove dirt and microorganisms. The availability of hand sanitizing products for use when water and soap are unavailable has increased in recent years. The aim of this systematic review was to collate scientific information on the efficacy of hand sanitizers compared with washing hands with soap and water for the removal of foodborne pathogens from the hands of food handlers. An extensive literature search was carried out using three electronic databases: Web of Science, Scopus, and PubMed. Twenty-eight scientific publications were ultimately included in the review. Analysis of this literature revealed various limitations in the scientific information owing to the absence of a standardized protocol for evaluating the efficacy of hand products and variation in experimental conditions. However, despite conflicting results, scientific evidence seems to support the historical skepticism about the use of waterless hand sanitizers in food preparation settings. Water and soap appear to be more effective than waterless products for removal of soil and microorganisms from hands. Alcohol-based products achieve rapid and effective inactivation of various bacteria, but their efficacy is generally lower against nonenveloped viruses. The presence of food debris significantly affects the microbial inactivation rate of hand sanitizers. PMID:27296611

  17. An experimentally validated parametrically excited vibration energy harvester with time-varying stiffness

    NASA Astrophysics Data System (ADS)

    Zaghari, Bahareh; Rustighi, Emiliano; Ghandchi Tehrani, Maryam

    2015-03-01

    Vibration energy harvesting is the transformation of vibration energy to electrical energy. The motivation of this work is to use vibration energy harvesting to power wireless sensors that could be used in inaccessible or hostile environments to transmit information for condition health monitoring. Although considerable work has been done in the area of energy harvesting, there is still a demand for making a robust and small vibration energy harvesters from random excitations in a real environment that can produce a reliable amount of energy. Parametrically excited harvesters can have time-varying stiffness. Parametric amplification is used to tune vibration energy harvesters to maximize energy gains at system superharmonics, often at twice the first natural frequency. In this paper the parametrically excited harvester with cubic and cubic parametric nonlinearity is introduced as a novel work. The advantages of having cubic and cubic nonlinearity are explained theoretically and experimentally.

  18. Posture modulates implicit hand maps.

    PubMed

    Longo, Matthew R

    2015-11-01

    Several forms of somatosensation require that afferent signals be informed by stored representations of body size and shape. Recent results have revealed that position sense relies on a highly distorted body representation. Changes of internal hand posture produce plastic alterations of processing in somatosensory cortex. This study therefore investigated how such postural changes affect implicit body representations underlying position sense. Participants localised the knuckles and tips of each finger in external space in two postures: the fingers splayed (Apart posture) or pressed together (Together posture). Comparison of the relative locations of the judgments of each landmark were used to construct implicit maps of represented hand structure. Spreading the fingers apart produced increases in the implicit representation of hand size, with no apparent effect on hand shape. Thus, changes of internal hand posture produce rapid modulation of how the hand itself is represented, paralleling the known effects on somatosensory cortical processing. PMID:26117153

  19. Hand Anthropometry and SMS Satisfaction

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Vimala; Yeow, Paul H. P.

    The effect of hand anthropometry on Short Message Service (SMS) satisfaction was investigated using structured questionnaire interviews with 110 subjects, aged between 17-25 years old. Hand size was measured to assess its effect on mobile phone design factors satisfaction whereas thumb circumference and length were measured for keypad design factors. Small hand-sized subjects were found to be more satisfied with mobile phone dimensions than large hand-sized subjects. Thumb circumference significantly affects users` satisfaction towards key size and space between keys whereas thumb length significantly affects keypad layout satisfaction. Both thumb circumference and length significantly correlate negatively with the corresponding keypad design factors. Results confirm that hand anthropometry do affect users messaging satisfaction. These findings should prove useful to mobile phone designers who could look into the possibility of designing customized mobile phones that cater to large hand and thumb sized users, so as to increase their subjective satisfaction.

  20. Responses of Diaphorina citri (Hemiptera: Psyllidae) to conspecific vibrational signals and synthetic mimics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mate-seeking in Diaphorina citri Kuwayama, a vector of the economically damaging huanglongbing citrus disease, typically includes male-female duetting behaviors. First, the male calls by beating its wings at ca. 170-250 Hz, producing vibrations that are transmitted along the host tree branches to th...

  1. Multi-fingered robotic hand

    NASA Technical Reports Server (NTRS)

    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.

  2. Hand controller commonality evaluation process

    NASA Technical Reports Server (NTRS)

    Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

    1990-01-01

    A hand controller evaluation process has been developed to determine the appropriate hand controller configurations for supporting remotely controlled devices. These devices include remote manipulator systems (RMS), dexterous robots, and remotely-piloted free flyers. Standard interfaces were developed to evaluate six different hand controllers in three test facilities including dynamic computer simulations, kinematic computer simulations, and physical simulations. The hand controllers under consideration were six degree-of-freedom (DOF) position and rate minimaster and joystick controllers, and three-DOF rate controllers. Task performance data, subjective comments, and anthropometric data obtained during tests were used for controller configuration recommendations to the SSF Program.

  3. Stery-hand: A new device to support hand disinfection.

    PubMed

    Szilagyi, Laszlo; Lehotsky, Akos; Nagy, Melinda; Haidegger, Tamas; Benyo, Balazs; Benyo, Zoltan

    2010-01-01

    Incomplete disinfection can cause serious complications in surgical care. The teaching of effective hand washing is crucial in modern medical training. To support the objective evaluation of hand disinfection, we developed a compact, mobile device, relying on digital imaging and image processing. The hardware consists of a metal case with matte black interior, ultra-violet lighting and a digital camera. Image segmentation and clustering are performed on a regular notebook. The hand washing procedures performed with a soap mixed with UV-reflective powder. This results the skin showing bright under UV light only on the treated (sterile) surfaces. When the surgeon inserts its hands into the box, the camera placed on the top takes an image of the hand for evaluation. The software performs the segmentation and clustering automatically. First, the hand contour is determined from the green intensity channel of the recorded RGB image. Then, the pixels of the green channel belonging to the hand are partitioned to three clusters using a quick, histogram based fuzzy c-means algorithm. The optimal threshold between the intensities of clean and dirty areas is extracted using these clusters, while the final approximated percentage of the clean area is computed using a weighting formula. The main advantage of our device is the ability to obtain objective and comparable result on the quality of hand disinfection. It may find its best use in the clinical education and training. PMID:21096021

  4. Hand in Hand: Media Literacy and Internet Safety

    ERIC Educational Resources Information Center

    Gallagher, Frank

    2011-01-01

    Internet safety cannot be effectively taught without also teaching media literacy. The two go hand in hand, and both are necessary, but neither is sufficient. To understand why, it is important to first appreciate what the real risks to children are. Many of the early Internet safety programs were based on a fear of predators. Predators turned out…

  5. Insect Vector Interactions with Persistently Transmitted Plant Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of the defined plant viruses are transmitted by insects of the Hemipteroid assemblage that includes aphids, whiteflies, leafhoppers, planthoppers and thrips. In this review we highlight progress made in research on vector interactions of the more than 200 plant viruses that are transmit...

  6. 47 CFR 90.542 - Broadband transmitting power limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing the Licensing and Use of Frequencies in... power limits apply to the 763-768/793-798 MHz band: (1) Fixed and base stations transmitting a signal in... transmitting a signal in the 763-768 MHz band with an emission bandwidth of 1 MHz or less must not exceed...

  7. 47 CFR 90.542 - Broadband transmitting power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing the Licensing and Use of Frequencies in... power limits apply to the 758-768/788-798 MHz band: (1) Fixed and base stations transmitting a signal in... transmitting a signal in the 758-768 MHz band with an emission bandwidth of 1 MHz or less must not exceed...

  8. Whitefly-transmitted viruses: cultural strategies in vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted viruses are important problems in agriculture on a global scale. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a notable vector because of the extensive number of viruses that it transmits and the extensive number of host plants that it feeds on. To help develop str...

  9. Chapter 11 Insect transmitted virus and mollicute disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-transmitted diseases of maize are found throughout the maize growing regions of the world. These diseases are caused by viruses, phytoplasmas and spiroplasmas. The pathogens, vectors and plant hosts for the major insect-transmitted diseases of maize world-wide are reviewed. Factors leading to...

  10. Dynamic Hand Gesture Recognition Using the Skeleton of the Hand

    NASA Astrophysics Data System (ADS)

    Ionescu, Bogdan; Coquin, Didier; Lambert, Patrick; Buzuloiu, Vasile

    2005-12-01

    This paper discusses the use of the computer vision in the interpretation of human gestures. Hand gestures would be an intuitive and ideal way of exchanging information with other people in a virtual space, guiding some robots to perform certain tasks in a hostile environment, or interacting with computers. Hand gestures can be divided into two main categories: static gestures and dynamic gestures. In this paper, a novel dynamic hand gesture recognition technique is proposed. It is based on the 2D skeleton representation of the hand. For each gesture, the hand skeletons of each posture are superposed providing a single image which is the dynamic signature of the gesture. The recognition is performed by comparing this signature with the ones from a gesture alphabet, using Baddeley's distance as a measure of dissimilarities between model parameters.

  11. Focal vibration in neurorehabilitation.

    PubMed

    Murillo, N; Valls-Sole, J; Vidal, J; Opisso, E; Medina, J; Kumru, H

    2014-04-01

    During the last decade, many studies have been carried out to understand the effects of focal vibratory stimuli at various levels of the central nervous system and to study pathophysiological mechanisms of neurological disorders as well as the therapeutic effects of focal vibration in neurorehabilitation. This review aimed to describe the effects of focal vibratory stimuli in neurorehabilitation including the neurological diseases or disorders like stroke, spinal cord injury, multiple sclerosis, Parkinson's' disease and dystonia. In conclusion, focal vibration stimulation is well tolerated, effective and easy to use, and it could be used to reduce spasticity, to promote motor activity and motor learning within a functional activity, even in gait training, independent from etiology of neurological pathology. Further studies are needed in the future well-designed trials with bigger sample size to determine the most effective frequency, amplitude and duration of vibration application in the neurorehabilitation. PMID:24842220

  12. Cyclone vibration effects

    SciTech Connect

    Gray, D.C.; Tillery, M.I.

    1981-09-01

    A Government Accounting Office review of coal mine dust sampling procedures recommended studies be performed to determine accuracy and precision of dust measurements taken with current equipment. The effects of vibration on the 10-mm Dorr-Oliver nylon cyclone run at a flow rate of 2 L/min were investigated. A total of 271 samples were taken during 95 tests. All tests lasted about 7 h each and were performed inside a 19 l capacity aerosol chamber. Coal dust concentrations of about 2 mg/m/SUP/3 in air and a respirable fraction of 25-30% were used. The effects of a variety of vibration frequencies and stroke lengths were tested in two modes (horizontal and vertical). At most frequencies and stroke lengths, vibration was found to have an insignificant effect on cyclone performance.

  13. Fiber optic vibration sensor

    DOEpatents

    Dooley, J.B.; Muhs, J.D.; Tobin, K.W.

    1995-01-10

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity. 2 figures.

  14. Fiber optic vibration sensor

    DOEpatents

    Dooley, Joseph B.; Muhs, Jeffrey D.; Tobin, Kenneth W.

    1995-01-01

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity.

  15. Digital vibration control techniques

    NASA Technical Reports Server (NTRS)

    Chapman, P.; Kim, B. K.; Boctor, W.

    1974-01-01

    Analog vibration control techniques are reviewed and are compared with digital techniques. The advantages of the digital methods over the analog methods are demonstrated. The following topics are covered: (1) methods of computer-controlled random vibration and reverberation acoustic testing; (2) methods of computer-controlled sinewave vibration testing; and (3) methods of computer-controlled shock testing. Basic concepts are stressed rather than specific techniques or equipment. General algorithms are described in the form of block diagrams and flow diagrams. Specific problems and potential problems are discussed. The material is computer sciences oriented but is kept at a level that facilitates an understanding of the basic concepts of computer-controlled induced environmental test systems.

  16. Externally tuned vibration absorber

    DOEpatents

    Vincent, Ronald J.

    1987-09-22

    A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

  17. The Epidemiology of Soil-Transmitted Helminths in Bihar State, India

    PubMed Central

    Greenland, Katie; Dixon, Ruth; Khan, Shabbir Ali; Gunawardena, Kithsiri; Kihara, Jimmy H.; Smith, Jennifer L.; Drake, Lesley; Makkar, Prerna; Singh, Sarman; Kumar, Sanjay

    2015-01-01

    Background Soil-transmitted helminths (STHs) infect over a billion individuals worldwide. In India, 241 million children are estimated to need deworming to avert the negative consequences STH infections can have on child health and development. In February-April 2011, 17 million children in Bihar State were dewormed during a government-led school-based deworming campaign. Prior to programme implementation, a study was conducted to assess STH prevalence in the school-age population to direct the programme. The study also investigated risk factors for STH infections, including caste, literacy, and defecation and hygiene practices, in order to inform the development of complementary interventions. Methods A cross-sectional survey was conducted among children in 20 schools in Bihar. In addition to providing stool samples for identification of STH infections, children completed a short questionnaire detailing their usual defecation and hand-hygiene practices. Risk factors for STH infections were explored. Results In January-February 2011, 1279 school children aged four to seventeen provided stool samples and 1157 children also completed the questionnaire. Overall, 68% of children (10-86% across schools) were infected with one or more soil-transmitted helminth species. The prevalence of ascariasis, hookworm and trichuriasis was 52%, 42% and 5% respectively. The majority of children (95%) practiced open defecation and reported most frequently cleansing hands with soil (61%). Increasing age, lack of maternal literacy and certain castes were independently associated with hookworm infection. Absence of a hand-washing station at the schools was also independently associated with A. lumbricoides infection. Conclusions STH prevalence in Bihar is high, and justifies mass deworming in school-aged children. Open defecation is common-place and hands are often cleansed using soil. The findings reported here can be used to help direct messaging appropriate to mothers with low levels

  18. 3w Transmitted Beam Diagnostic at the Omega Laser Facility

    SciTech Connect

    Froula, D H; Rekow, V; Sorce, C; Piston, K; Knight, R; Alvarez, S; Griffith, R; Hargrove, D; Ross, J S; Dixit, S; Pollock, B; Divol, L; Glenzer, S H; Armstrong, W; Bahr, R; Thorp, K; Pien, G

    2006-04-24

    A 3{omega} transmitted beam diagnostic has been commissioned on the Omega Laser at the Laboratory for Laser Energetics, University of Rochester [Soures et.al., Laser Part. Beams 11 (1993)]. Transmitted light from one beam is collected by a large focusing mirror and directed onto a diagnostic platform. The near field of the transmitted light is imaged; the system collects information from twice the original f-cone of the beam. Two gated optical cameras capture the near field image of the transmitted light. Thirteen spatial positions around the measurement region are temporally resolved using fast photodiodes to allow a measure of the beam spray evolution. The Forward stimulated Raman scattering and forward simulated Brillion scattering are spectrally and temporally resolved at 5 independent locations within twice the original f-cone. The total transmitted energy is measured in two spectral bands ({delta}{lambda} < 400 nm and {delta}{lambda} > 400 nm).

  19. Transfusion transmitted diseases in perioperative and intensive care settings.

    PubMed

    Das, Rekha; Hansda, Upendra

    2014-09-01

    Patients in the perioperative period and intensive care unit are commonly exposed to blood transfusion (BT). They are at increased risk of transfusion transmitted bacterial, viral and protozoal diseases. The risk of viral transmission has decreased steadily, but the risk of bacterial transmission remains same. Bacterial contamination is more in platelet concentrates than in red cells and least in plasma. The chances of sepsis, morbidity and mortality depend on the number of transfusions and underlying condition of the patient. Challenges to safe BT continue due to new emerging pathogens and various management problems. Strategies to restrict BT, optimal surgical and anaesthetic techniques to reduce blood loss and efforts to develop transfusion alternatives should be made. Literature search was performed using search words/phrases blood transfusion, transfusion, transfusion transmitted diseases, transfusion transmitted bacterial diseases, transfusion transmitted viral diseases, transfusion transmitted protozoal diseases or combinations, on PubMed and Google Scholar from 1990 to 2014. PMID:25535416

  20. Mycoplasma genitalium: Is It a Sexually Transmitted Pathogen?

    PubMed

    Manhart, Lisa E; Kay, Noa

    2010-07-01

    Mycoplasma genitalium is an emerging pathogen that has been detected in the male and female reproductive tracts. It is an established cause of nongonococcal urethritis and evidence linking it to cervicitis, endometritis, and tubal factor infertility is accumulating. Whether a pathogen is sexually transmitted has important implications for clinical management because partner management strategies are an essential part of the treatment plan for sexually transmitted infections. However, mere detection in the genital tract and associations with reproductive tract disease are insufficient to conclude that an organism is sexually transmitted. Therefore, to assess whether M. genitalium is sexually transmitted, we evaluated the literature in terms of associations with established risk factors for other sexually transmitted infections, comparisons of sexually experienced individuals to nonsexually experienced individuals, consideration of other modes of transmission, assessment of concordant infection status among sexual partners, and examination of molecular strain typing in concordantly infected partners. PMID:21308546

  1. Vibrational spectroscopy of resveratrol

    NASA Astrophysics Data System (ADS)

    Billes, Ferenc; Mohammed-Ziegler, Ildikó; Mikosch, Hans; Tyihák, Ernő

    2007-11-01

    In this article the authors deal with the experimental and theoretical interpretation of the vibrational spectra of trans-resveratrol (3,5,4'-trihydroxy- trans-stilbene) of diverse beneficial biological activity. Infrared and Raman spectra of the compound were recorded; density functional calculations were carried out resulting in the optimized geometry and several properties of the molecule. Based on the calculated force constants, a normal coordinate analysis yielded the character of the vibrational modes and the assignment of the measured spectral bands.

  2. Detection of atomic force microscopy cantilever displacement with a transmitted electron beam

    NASA Astrophysics Data System (ADS)

    Wagner, R.; Woehl, T. J.; Keller, R. R.; Killgore, J. P.

    2016-07-01

    The response time of an atomic force microscopy (AFM) cantilever can be decreased by reducing cantilever size; however, the fastest AFM cantilevers are currently nearing the smallest size that can be detected with the conventional optical lever approach. Here, we demonstrate an electron beam detection scheme for measuring AFM cantilever oscillations. The oscillating AFM tip is positioned perpendicular to and in the path of a stationary focused nanometer sized electron beam. As the tip oscillates, the thickness of the material under the electron beam changes, causing a fluctuation in the number of scattered transmitted electrons that are detected. We demonstrate detection of sub-nanometer vibration amplitudes with an electron beam, providing a pathway for dynamic AFM with cantilevers that are orders of magnitude smaller and faster than the current state of the art.

  3. Adaptive control of an active seat for occupant vibration reduction

    NASA Astrophysics Data System (ADS)

    Gan, Zengkang; Hillis, Andrew J.; Darling, Jocelyn

    2015-08-01

    The harmful effects on human performance and health caused by unwanted vibration from vehicle seats are of increasing concern. This paper presents an active seat system to reduce the vibration level transmitted to the seat pan and the occupants' body under low frequency periodic excitation. Firstly, the detail of the mechanical structure is given and the active seat dynamics without external load are characterized by vibration transmissibility and frequency responses under different excitation forces. Owing the nonlinear and time-varying behaviour of the proposed system, a Filtered-x least-mean-square (FXLMS) adaptive control algorithm with on-line Fast-block LMS (FBLMS) identification process is employed to manage the system operation for high vibration cancellation performance. The effectiveness of the active seat system is assessed through real-time experimental tests using different excitation profiles. The system identification results show that an accurate estimation of the secondary path is achieved by using the FBLMS on-line technique. Substantial reduction is found for cancelling periodic vibration containing single and multiple frequencies. Additionally, the robustness and stability of the control system are validated through transient switching frequency tests.

  4. On the transmissibilities of nonlinear vibration isolation system

    NASA Astrophysics Data System (ADS)

    Lu, Zeqi; Brennan, Michael J.; Chen, Li-Qun

    2016-08-01

    Transmissibility is a key parameter to quantify the effectiveness of a vibration isolation system. Under harmonic excitation, the force transmissibility of a linear vibration isolation system is defined as the ratio between the amplitude of the force transmitted to the host structure and the excitation force amplitude, and the displacement transmissibility is the ratio between the displacement amplitude of the payload and that of the base. For a nonlinear vibration isolation system, the force or the displacement responses usually have more frequency components than the excitation. For a harmonic excitation, the response may be periodic, quasi-periodic or chaotic. Therefore, the amplitude ratio cannot well define the transmissibility. The root-mean-square ratio of the response to the excitation is suggested to define the transmissibility. The significance of the modified transmissibility is highlighted in a nonlinear two-stage vibration isolation system consisting of two linear spring connected linear vibration isolators with two additional horizontal linear springs. Harmonic balance method (HBM) is applied to determine the responses with the fundamental and third harmonic. Numerical simulations reveal that chaos may occur in the responses. In both cases, the modified transmissibility works while the original definition cannot be applied to chaotic response.

  5. Distributing Data from Desktop to Hand-Held Computers

    NASA Technical Reports Server (NTRS)

    Elmore, Jason L.

    2005-01-01

    A system of server and client software formats and redistributes data from commercially available desktop to commercially available hand-held computers via both wired and wireless networks. This software is an inexpensive means of enabling engineers and technicians to gain access to current sensor data while working in locations in which such data would otherwise be inaccessible. The sensor data are first gathered by a data-acquisition server computer, then transmitted via a wired network to a data-distribution computer that executes the server portion of the present software. Data in all sensor channels -- both raw sensor outputs in millivolt units and results of conversion to engineering units -- are made available for distribution. Selected subsets of the data are transmitted to each hand-held computer via the wired and then a wireless network. The selection of the subsets and the choice of the sequences and formats for displaying the data is made by means of a user interface generated by the client portion of the software. The data displayed on the screens of hand-held units can be updated at rates from 1 to

  6. A transmit/reflect switchable frequency selective surface based on all dielectric metamaterials

    NASA Astrophysics Data System (ADS)

    Yu, Fei; Wang, Jun; Wang, Jiafu; Ma, Hua; Du, Hongliang; Zhuo, Xu; Qu, Shaobo

    2015-12-01

    In this paper, we propose a novel transmit/reflect switchable frequency selective surface (FSS) in millimeter wave band based on the effective medium theory under quasi-static limit, which is designed with square-hole elements cut from continuum dielectric plates. The building elements of the surface are composed of all dielectric metamaterial rather than metal material. With proper structural design and parameters tuning, the resonance frequencies can be tuned appropriately. The frequency response of the surface can be switched from that of a reflecting structure to a transmitting one by rotating the surface 90°, which means under different incident polarizations. The reflective response can be realized due to the effect of electric and magnetic resonances. Theoretical analysis shows that the reflective response arises from impedance mismatching by electric and magnetic resonances. And the transmitting response is the left-handed passband, arises from the coupling of the electric and magnetic resonances. In addition, effective electromagnetic parameters and the dynamic induced field distributions are analyzed to explain the mechanism of the responses. The method can also be used to design switchable all-dielectric FSS with continuum structures in other frequencies.

  7. VibeComm: radio-free wireless communication for smart devices using vibration.

    PubMed

    Hwang, Inhwan; Cho, Jungchan; Oh, Songhwai

    2014-01-01

    This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility. PMID:25390406

  8. VibeComm: Radio-Free Wireless Communication for Smart Devices Using Vibration

    PubMed Central

    Hwang, Inhwan; Cho, Jungchan; Oh, Songhwai

    2014-01-01

    This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility. PMID:25390406

  9. Resonance in herbaceous plant stems as a factor in vibrational communication of pentatomid bugs (Heteroptera: Pentatomidae)

    PubMed Central

    Polajnar, Jernej; Svenšek, Daniel; Čokl, Andrej

    2012-01-01

    Pentatomid bugs communicate using substrate-borne vibrational signals that are transmitted along herbaceous plant stems in the form of bending waves with a regular pattern of minimal and maximal amplitude values with distance. We tested the prediction that amplitude variation is caused by resonance, by measuring amplitude profiles of different vibrational pulses transmitted along the stem of a Cyperus alternifolius plant, and comparing their patterns with calculated spatial profiles of corresponding eigenfrequencies of a model system. The measured distance between nodes of the amplitude pattern for pulses with different frequencies matches the calculated values, confirming the prediction that resonance is indeed the cause of amplitude variation in the studied system. This confirmation is supported by the resonance profile obtained by a frequency sweep, which matches theoretical predictions of the eigenfrequencies of the studied system. Signal bandwidth influences the amount of amplitude variation. The effect of both parameters on signal propagation is discussed in the context of insect vibrational communication. PMID:22298817

  10. Glass formation and optical properties of Ge-Te-Ga-CuI far-IR transmitting chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    He, Yuju; Wang, Xunsi; Nie, Qiuhua; Xu, Yinsheng; Xu, Tiefeng; Dai, Sixun

    2013-09-01

    To discover the signs of life on terrestrial planets, we must accurately detect the existence of CO2, which has two vibrational absorption bands at 4 μm and 16 μm. Therefore optical materials be able to transmit light far beyond 20 μm are essential for manufacturing these detectors. In this paper, a series of Ge-Te-Ga-CuI far-IR transmitting chalcogenide glasses were synthesized by conventional melt-quenching method and their glass-forming region was determined. Properties measurements including X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Vis-NIR and IR transmitting spectra were performed on glasses. The results of XRD measurements confirmed the amorphous state of studied glasses. With the help of Ga and CuI, these glasses have high glass transition temperature Tg (>175 °C), indicating their good thermal stability. The allowed indirect transition of samples was also calculated according to the Tauc equation. The infrared transmission spectra measured by Fourier transform infrared spectrometer (FTIR) show that these glasses all have wide optical transmitting window from 1.68 to 25 μm revealing that it may have great potential for application in far-IR material fields.

  11. Cable Modems' Transmitted RF: A Study of SNR, Error Rates, Transmit Levels, and Trouble Call Metrics

    ERIC Educational Resources Information Center

    Tebbetts, Jo A.

    2013-01-01

    Hypotheses were developed and tested to measure the cable modems operational metrics response to a reconfiguration of the cable modems' transmitted RF applied to the CMTS. The purpose of this experiment was to compare two groups on the use of non-federal RF spectrum to determine if configuring the cable modems' transmitted RF from 25.2…

  12. Gage for evaluating rheumatoid hands

    NASA Technical Reports Server (NTRS)

    Houge, J. C.; Plautz, K. A.

    1981-01-01

    Two-axis goniometer accurately measures movements of fingers about knuckle joints, diagnosing hands structurally changed by rheumatoid arthritis. Instrument measures lateral movement which is small in normal knuckles but increased in diseased joints. Goniometer is two connected protractors that simultaneously measure angles in perpindicular planes. Dials are offset to clear bony protuberances; extension and offset adjustments span any hand size.

  13. Handwashing: Clean Hands Save Lives

    MedlinePlus

    ... and what you can do if soap and clean, running water are not available. Whether you are at home, at work, traveling, or already sick, find out how good hand hygiene can protect you, your family, and others. More… Featured Video Keeping our hands clean is one of the best things we can ...

  14. Robot Forearm and Dexterous Hand

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.

    2005-01-01

    An electromechanical hand-and-forearm assembly has been developed for incorporation into an anthropomorphic robot that would be used in outer space. The assembly is designed to offer manual dexterity comparable to that of a hand inside an astronaut s suit; thus, the assembly may also be useful as a prosthesis or as an end effector on an industrial robot.

  15. Hand controller commonality evaluation process

    NASA Technical Reports Server (NTRS)

    Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

    1993-01-01

    Hand controller selection for NASA's Orbiter and Space Station Freedom is an important area of human-telerobot interface design and evaluation. These input devices will control remotely operated systems that include large crane-like manipulators (e.g., Remote Manipulator System or RMS), smaller, more dexterous manipulators (e.g., Flight Telerobotic Servicer or FTS), and free flyers (e.g., Orbital Maneuvering Vehicle or OMV). Candidate hand controller configurations for these systems vary in many ways: shape, size, number of degrees-of-freedom (DOF), operating modes, provision of force reflection, range of movement, and 'naturalness' of use. Unresolved design implementation issues remain, including such topics as how the current Orbiter RMS rotational and translational rate hand controllers compare with the proposed Space Station Freedom hand controllers, the advantages that position hand controllers offer for these applications, and whether separate hand controller configurations are required for each application. Since previous studies contain little empirical hand controller task performance data, a controlled study is needed that tests Space Station Freedom candidate hand controllers during representative tasks. This study also needs to include anthropometric and biomechanical considerations.

  16. The Work of the Hand

    ERIC Educational Resources Information Center

    Ludick, Pat

    2013-01-01

    Recognizing Maria and Mario Montessori's reverence for the hand, Pat Ludick takes the reader into the wonder of the human body, mind, and spirit and across the planes of education, into the making of a whole personality and grounded intelligence that is ready for the adult world. Putting the hand front and center, she lyrically evolves an overview…

  17. The Left-Handed Writer.

    ERIC Educational Resources Information Center

    Bloodsworth, James Gaston

    Contrary to the beliefs of many, right-handedness is not a single factor existing in almost all people, with a few exceptions termed left-handed: neither extreme exists independently of the other. During the first 4 years of life there is a period of fluctuation between right and left-handed dominance. Statistics and findings vary in determining…

  18. Vibration Propagation in Spider Webs

    NASA Astrophysics Data System (ADS)

    Hatton, Ross; Otto, Andrew; Elias, Damian

    Due to their poor eyesight, spiders rely on web vibrations for situational awareness. Web-borne vibrations are used to determine the location of prey, predators, and potential mates. The influence of web geometry and composition on web vibrations is important for understanding spider's behavior and ecology. Past studies on web vibrations have experimentally measured the frequency response of web geometries by removing threads from existing webs. The full influence of web structure and tension distribution on vibration transmission; however, has not been addressed in prior work. We have constructed physical artificial webs and computer models to better understand the effect of web structure on vibration transmission. These models provide insight into the propagation of vibrations through the webs, the frequency response of the bare web, and the influence of the spider's mass and stiffness on the vibration transmission patterns. Funded by NSF-1504428.

  19. The hand of Homo naledi

    PubMed Central

    Kivell, Tracy L.; Deane, Andrew S.; Tocheri, Matthew W.; Orr, Caley M.; Schmid, Peter; Hawks, John; Berger, Lee R.; Churchill, Steven E.

    2015-01-01

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

  20. The hand of Homo naledi.

    PubMed

    Kivell, Tracy L; Deane, Andrew S; Tocheri, Matthew W; Orr, Caley M; Schmid, Peter; Hawks, John; Berger, Lee R; Churchill, Steven E

    2015-01-01

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

  1. 3D Printed Robotic Hand

    NASA Technical Reports Server (NTRS)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  2. Development of hand surgery: education of hand surgeons.

    PubMed

    Omer, G E

    2000-07-01

    An organized experience in the care of hand injuries and infections was not available until World War II, when military hand centers were established. Dr Sterling Bunnell was designated as a special civilian consultant to the Secretary of War. The surgeons in the military services during World War II became the nucleus of the American Society for Surgery of the Hand (ASSH). Following World War II and the Korean War there was a major shift toward medical subspecialization, and the growth of surgery of the hand as a subspecialty parallels that trend. The ASSH initiated a coordinated effort to improve the educational experience, and in 1967 the ASSH Resident Training Committee was evaluating hand training programs. The ASSH developed a comprehensive program in continuing medical education, and received full accreditation from the American Medical Association Council on Medical Education. The American Medical Association has included hand surgery on its list of designated specialties since 1975. In 1973, the bylaws of the American Board of Medical Specialties were revised to provide special certification. The ASSH developed a proposal for a certificate of added qualification in surgery of the hand that was presented to the three primary boards (orthopaedic, plastic, surgery) and the ad hoc joint Committee on Surgery of the Hand was organized in 1982. An application for a certificate of added qualification in surgery was developed by the Joint Committee on Surgery of the Hand and approved by all three boards in 1985 and the ABMS in 1986. The first examination for the certificate of added qualification in surgery was held in 1989. PMID:10913201

  3. Vibration of Shells

    NASA Technical Reports Server (NTRS)

    Leissa, A. W.

    1973-01-01

    The vibrational characteristics and mechanical properties of shell structures are discussed. The subjects presented are: (1) fundamental equations of thin shell theory, (2) characteristics of thin circular cylindrical shells, (3) complicating effects in circular cylindrical shells, (4) noncircular cylindrical shell properties, (5) characteristics of spherical shells, and (6) solution of three-dimensional equations of motion for cylinders.

  4. C0 Vibrational analysis

    SciTech Connect

    Moore, Craig D.; Johnson, Todd; Martens, Mike; Syphers, Mike; McCrory, E.; McGee, Mike; Reilly, Rob; /Fermilab

    1999-08-01

    This is an attempt to document some of the measurements and analysis relating to the modulation of the spill due to the vibration of the magnets in the new C0 area. Not all of the relevant graphs were saved at the time, however an attempt has been made to show representative illustrations albeit not in the proper chronological order.

  5. Compact Vibration Damper

    NASA Technical Reports Server (NTRS)

    Ivanco, Thomas G. (Inventor)

    2014-01-01

    A vibration damper includes a rigid base with a mass coupled thereto for linear movement thereon. Springs coupled to the mass compress in response to the linear movement along either of two opposing directions. A converter coupled to the mass converts the linear movement to a corresponding rotational movement. A rotary damper coupled to the converter damps the rotational movement.

  6. Polyatomic molecule vibrations

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Polyatomic molecule vibrations are analyzed as harmonic vibrations along normal coordinates. The energy eigenvalues are found for linear and nonlinear symmetric triatomic molecules for valence bond models of the potential function with arbitrary coupling coefficients; such models can usually be fitted to observed energy levels with reasonably good accuracy. Approximate normal coordinates for the H2O molecule are discussed. Degenerate vibrational modes such as occur in CO2 are analyzed and expressions for Fermi resonance between close-lying states of the same symmetry are developed. The bending modes of linear triatomic molecules are expressed in terms of Laguerre polynomials in cylindrical coordinates as well as in terms of Hermite polynomials in Cartesian coordinates. The effects of large-amplitude bending such as occur in the C3 molecule are analyzed, along with anharmonic effects, which split the usually degenerate bending mode energy levels. Finally, the vibrational frequencies, degeneracies, and symmetry properties of XY3, X2Y2, and XY4 type molecules are discussed.

  7. Blade Vibration Measurement System

    NASA Technical Reports Server (NTRS)

    Platt, Michael J.

    2014-01-01

    The Phase I project successfully demonstrated that an advanced noncontacting stress measurement system (NSMS) could improve classification of blade vibration response in terms of mistuning and closely spaced modes. The Phase II work confirmed the microwave sensor design process, modified the sensor so it is compatible as an upgrade to existing NSMS, and improved and finalized the NSMS software. The result will be stand-alone radar/tip timing radar signal conditioning for current conventional NSMS users (as an upgrade) and new users. The hybrid system will use frequency data and relative mode vibration levels from the radar sensor to provide substantially superior capabilities over current blade-vibration measurement technology. This frequency data, coupled with a reduced number of tip timing probes, will result in a system capable of detecting complex blade vibrations that would confound traditional NSMS systems. The hardware and software package was validated on a compressor rig at Mechanical Solutions, Inc. (MSI). Finally, the hybrid radar/tip timing NSMS software package and associated sensor hardware will be installed for use in the NASA Glenn spin pit test facility.

  8. Nonlinear vibrational microscopy

    DOEpatents

    Holtom, Gary R.; Xie, Xiaoliang Sunney; Zumbusch, Andreas

    2000-01-01

    The present invention is a method and apparatus for microscopic vibrational imaging using coherent Anti-Stokes Raman Scattering or Sum Frequency Generation. Microscopic imaging with a vibrational spectroscopic contrast is achieved by generating signals in a nonlinear optical process and spatially resolved detection of the signals. The spatial resolution is attained by minimizing the spot size of the optical interrogation beams on the sample. Minimizing the spot size relies upon a. directing at least two substantially co-axial laser beams (interrogation beams) through a microscope objective providing a focal spot on the sample; b. collecting a signal beam together with a residual beam from the at least two co-axial laser beams after passing through the sample; c. removing the residual beam; and d. detecting the signal beam thereby creating said pixel. The method has significantly higher spatial resolution then IR microscopy and higher sensitivity than spontaneous Raman microscopy with much lower average excitation powers. CARS and SFG microscopy does not rely on the presence of fluorophores, but retains the resolution and three-dimensional sectioning capability of confocal and two-photon fluorescence microscopy. Complementary to these techniques, CARS and SFG microscopy provides a contrast mechanism based on vibrational spectroscopy. This vibrational contrast mechanism, combined with an unprecedented high sensitivity at a tolerable laser power level, provides a new approach for microscopic investigations of chemical and biological samples.

  9. Vibrational characteristics of harp soundboards.

    PubMed

    Waltham, Chris; Kotlicki, Andrzej

    2008-09-01

    Harps exist in different forms, from large factory-made concert harps to small hand-made folk harps. This variety presents both a challenge and an opportunity for acousticians. The musical quality of a harp depends on many factors, but key among these is the soundboard. This work sets out to define some general desirable qualities of a harp soundboard. First, in order to understand the relationship between the vibrational behavior of a bare soundboard and that of a completed instrument, a 36-string harp was built from scratch. Measurements were made at each stage of construction, and the results showed how the bare soundboard properties affect those of the finished harp. Second, the soundboards of several harps of different sizes were assessed by measuring the admittances along the string bar. These data showed that one relationship crucial to the quality of the soundboard is that between the modal shapes and modal frequencies of the soundboard, and the position and fundamental frequencies of the strings attached to it. A general statement is made about this relationship, one which should be of use to harp makers. PMID:19045667

  10. High-Temperature Vibration Damper

    NASA Technical Reports Server (NTRS)

    Clarke, Alan; Litwin, Joel; Krauss, Harold

    1987-01-01

    Device for damping vibrations functions at temperatures up to 400 degrees F. Dampens vibrational torque loads as high as 1,000 lb-in. but compact enough to be part of helicopter rotor hub. Rotary damper absorbs energy from vibrating rod, dissipating it in turbulent motion of viscous hydraulic fluid forced by moving vanes through small orifices.

  11. Vibration characteristics of ultrasonic complex vibration for hole machining

    NASA Astrophysics Data System (ADS)

    Asami, Takuya; Miura, Hikaru

    2012-05-01

    Complex vibration sources that use diagonal slits as a longitudinal-torsional vibration converter have been applied to ultrasonic motors, ultrasonic rock drilling, and ultrasonic welding. However, there are few examples of the application of these sources to ultrasonic machining in combination with an abrasive. Accordingly, a new method has been developed for machining of holes in brittle materials by using the ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn with a diagonal slit vibration converter. In this paper, we compared vibration of a uniform rod and a hollow-type stepped horn, both with diagonal slits, when the conditions of the diagonal slits are constant.

  12. Inaudible temporomandibular joint vibrations.

    PubMed

    Widmalm, Sven E; Bae, Hanna E K; Djurdjanovic, Dragan; McKay, Duane C

    2006-07-01

    The aim was to test the hypothesis that inaudible vibrations with significant amounts of energy increasing during jaw movements can be recorded in the temporomandibular joint (TMJ) area. Twenty one subjects, who could perform wide opening movements without feeling discomfort, 12 with and 9 without TMJ sounds audible at conventional auscultation with a stethoscope, were included. Recordings were made during opening-closing, 2/s without tooth contact, and during mandibular rest, using accelerometers with a flat frequency response between the filter cutoff frequencies 0.1 Hz and 1000 Hz. The signals were digitized using a 24 bits card and sampled with the rate 96000 Hz. Power spectral analyses, and independent and paired samples t-tests were used in the analysis of the vibration power observed in frequency bands corresponding to audible and inaudible frequencies. An alpha-level of 5% was chosen for accepting a difference as being significant. In the group with audible sounds, about 47% of the total vibration energy was in the inaudible area below 20 Hz during opening-closing and about 76% during mandibular rest. In the group without audible sounds, the corresponding proportions were significantly different, 85% vs. 69%. The energy content of the vibrations, both those below and those above 20 Hz, increased significantly during jaw movement in both groups. Furthermore, percentage of signal energy above 20 Hz showed a noticeable increase in the group of subjects with audible sounds. This can physically be explained by decreased damping properties of damaged tissues surrounding the TMJ. Vibrations in the TMJ area can be observed with significant portions in the inaudible area below 20 Hz both during mandibular rest and during jaw movements whether or not the subjects have audible joint sounds. Further studies are needed to identify sources and evaluate possible diagnostic value. PMID:16933462

  13. Compensated vibrating optical fiber pressure measuring device

    DOEpatents

    Fasching, George E.; Goff, David R.

    1987-01-01

    A microbending optical fiber is attached under tension to a diaphragm to se a differential pressure applied across the diaphragm which it causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into a electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

  14. Transmit versus receive gains for microwave dish antennas

    NASA Astrophysics Data System (ADS)

    Richter, J. L.

    1983-06-01

    For the microwave dish antennas, the antenna gain when transmitting can be different, and is usually less, than that of the same antenna when receiving. The theory of the far field transmit and receive antenna gains is developed for the classical dish as well as for the general case. Aperture functions are derived for use in the integral form of the Fraunhofer diffraction equation. Both the aberration effects of the dish and the angular distribution of the feed are taken into account. Calculations of transmit and receive antenna patterns and gains are compared for the f/1 classical dish for various amounts of feed spillover.

  15. Transmitted Laser Beam Diagnostic at the Omega Laser Facility

    SciTech Connect

    Niemann, C; Antonini, G; Compton, S; Glenzer, S; Hargrove, D; Moody, J; Kirkwood, R; Rekow, V; Sorce, C; Armstrong, W; Bahr, R; Keck, R; Pien, G; Seka, W; Thorp, K

    2004-04-01

    We have developed and commissioned a transmitted beam diagnostic (TBD) for the 2{omega} high intensity interaction beam at the Omega laser facility. The TBD consists of a bare-surface reflector mounted near the target, which collects and reflects 4% of the transmitted light to a detector assembly outside the vacuum chamber. The detector includes a time integrating near-field camera that measures beam spray, deflection and the absolute transmitted power. We present a detailed description of the instrument and the calibration method and include first measurements on laser heated gasbag targets to demonstrate the performance of the diagnostic.

  16. The Marble-Hand Illusion

    PubMed Central

    Senna, Irene; Maravita, Angelo; Bolognini, Nadia; Parise, Cesare V.

    2014-01-01

    Our body is made of flesh and bones. We know it, and in our daily lives all the senses constantly provide converging information about this simple, factual truth. But is this always the case? Here we report a surprising bodily illusion demonstrating that humans rapidly update their assumptions about the material qualities of their body, based on their recent multisensory perceptual experience. To induce a misperception of the material properties of the hand, we repeatedly gently hit participants' hand with a small hammer, while progressively replacing the natural sound of the hammer against the skin with the sound of a hammer hitting a piece of marble. After five minutes, the hand started feeling stiffer, heavier, harder, less sensitive, unnatural, and showed enhanced Galvanic skin response (GSR) to threatening stimuli. Notably, such a change in skin conductivity positively correlated with changes in perceived hand stiffness. Conversely, when hammer hits and impact sounds were temporally uncorrelated, participants did not spontaneously report any changes in the perceived properties of the hand, nor did they show any modulation in GSR. In two further experiments, we ruled out that mere audio-tactile synchrony is the causal factor triggering the illusion, further demonstrating the key role of material information conveyed by impact sounds in modulating the perceived material properties of the hand. This novel bodily illusion, the ‘Marble-Hand Illusion', demonstrates that the perceived material of our body, surely the most stable attribute of our bodily self, can be quickly updated through multisensory integration. PMID:24621793

  17. Vibrational Conical Intersections: Implications for Ultrafast Vibrational Dynamics

    NASA Astrophysics Data System (ADS)

    Dawadi, Mahesh; Prasad Thapaliya, Bishnu; Bhatta, Ram; Perry, David

    2015-03-01

    The presence of conical intersections (CIs) between electronic potential energy surfaces is known to play a key role in ultrafast electronic relaxation in diverse circumstances. Recent reports have documented the existence of vibrational CIs connecting vibrationally adiabatic surfaces. Just as electronic CIs are now appreciated to be ubiquitous, controlling the rates of many photochemical processes, the present work on methanol and methyl mercaptan suggests that vibrational CIs may also be widespread, possibly controlling the outcome of some high-energy processes where vibrationally excited species are present. Other examples of vibrational CIs include the vibrational Jahn-Teller effect in C3V organic molecules and transition metal complexes. While the present work addresses only the couplings within bound molecules, the concept of vibrational CIs providing pathways for ultrafast relaxation also applies to molecular collisions. This work is supported by DOE (DEFG02-90ER14151).

  18. Active vibration control of structures undergoing bending vibrations

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor)

    1995-01-01

    An active vibration control subassembly for a structure (such as a jet engine duct or a washing machine panel) undergoing bending vibrations caused by a source (such as the clothes agitator of the washing machine) independent of the subassembly. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the structure such that vibrations in the plate induced by the AC signal cause canceling bending vibrations in the structure and such that the plate is compressively pre-stressed along the structure when the structure is free of any bending vibrations. The compressive prestressing increases the amplitude of the canceling bending vibrations before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction.

  19. Effects of different vibration exercises on bench press.

    PubMed

    Marín, P J; Torres-Luque, G; Hernández-García, R; García-López, D; Garatachea, N

    2011-10-01

    This study was undertaken to analyze the effects of different vibration recovery strategies via feet or hands on the number of repetitions performed and on mean velocity, peak velocity and blood lactate concentration during consecutive bench-press sets. 9 elite judo athletes performed 3 sets of bench press at 60% of one-repetition maximum (1RM), leading to failure and allowing a 180 s rest period between sets. During the rest period, 1 of the 3 following procedures was performed: 150 s rest plus 30 s push-up vibration exercise (Push-up), 150 s rest plus 30 s squat vibration exercise (Squat) or 180 s only rest (Passive). Statistical analysis revealed that the Squat condition resulted in a significant increase in the number of repetitions achieved, in comparison with all other rest strategies. However, kinematic parameters and blood lactate concentration were not affected by vibration. These data suggest that a vibration stimulus applied to the feet, between sets, can result in positive improvements in upper body resistance exercise performance. Although the mechanisms are not fully understood, this positive effect of vibration could be due to an increased motor cortex excitability and voluntary drive. PMID:21590639

  20. Reed vibration in lingual organ pipes without the resonators

    NASA Astrophysics Data System (ADS)

    Miklós, András; Angster, Judit; Pitsch, Stephan; Rossing, Thomas D.

    2003-02-01

    Vibrations of plucked and blown reeds of lingual organ pipes without the resonators have been investigated. Three rather surprising phenomena are observed: the frequency of the reed plucked by hand is shifted upwards for large-amplitude plucking, the blown frequency is significantly higher than the plucked one, and peaks halfway between the harmonics of the fundamental frequency appear in the spectrum of the reed velocity. The dependence of the plucked frequency on the length of the reed reveals that the vibrating length at small vibrations is 3 mm shorter than the apparent free length. The frequency shift for large-amplitude plucking is explained by the periodic change of the vibrating length during the oscillation. Reed vibrations of the blown pipe can be described by a physical model based on the assumption of air flow between the reed and the shallot. Aerodynamic effects may generate and sustain the oscillation of the reed without acoustic feedback. The appearance of subharmonics is explained by taking into account the periodic modulation of the stress in the reed material by the sound field. Therefore, a parametric instability appears in the differential equation of vibration, leading to the appearance of subharmonics.

  1. Compartment Syndrome of the Hand.

    PubMed

    Oak, Nikhil R; Abrams, Reid A

    2016-07-01

    Hand compartment syndrome has many etiologies; untreated, it has dire functional consequences. Intracompartmental pressure exceeding capillary filling pressure causes decreased tissue perfusion resulting in progressive ischemic death of compartment contents. Clinical findings can evolve. Serial physical examinations are recommended and, if equivocal, interstitial pressure monitoring is indicated. Definitive management is emergent fasciotomies with incisions designed to decompress the involved hand compartments, which could include the thenar, hypothenar, and interosseous compartments, and the carpal tunnel. Careful wound care, edema management, splinting, and hand therapy are critical. Therapy should start early postoperatively, possibly before wound closure. PMID:27241383

  2. Vibration sensing method and apparatus

    DOEpatents

    Barna, Basil A.

    1989-04-25

    A method and apparatus for nondestructive evaluation of a structure is disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration.

  3. Vibration sensing method and apparatus

    DOEpatents

    Barna, B.A.

    1989-04-25

    A method and apparatus for nondestructive evaluation of a structure are disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration. 4 figs.

  4. Vibration sensing method and apparatus

    DOEpatents

    Barna, B.A.

    1987-07-07

    A method and apparatus for nondestructive evaluation of a structure is disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration. 4 figs.

  5. Free vibrations of delaminated beams

    NASA Technical Reports Server (NTRS)

    Shen, M.-H. H.; Grady, J. E.

    1992-01-01

    Free vibration of laminated composite beams is studied. The effect of interply delaminations on natural frequencies and mode shapes is evaluated both analytically and experimentally. A generalized vibrational principle is used to formulate the equation of motion and associated boundary conditions for the free vibration of a composite beam with a delamination of arbitrary size and location. The effect of coupling between longitudinal vibration and bending vibration is considered. This coupling effect is shown to significantly affect the calculated natural frequencies and mode shapes of the delaminated beam.

  6. Sex Partner with No Zika Symptoms Transmits Virus: CDC

    MedlinePlus

    ... html Sex Partner With No Zika Symptoms Transmits Virus: CDC New report also highlights ties between Zika ... News) -- U.S. health officials report that the Zika virus can be spread sexually even when a partner ...

  7. Device transmits rotary motion through hermetically sealed wall

    NASA Technical Reports Server (NTRS)

    Porter, R. N.

    1964-01-01

    A wobble plate, metal bellows, and two shafts, assembled in a four-section housing, make it possible to transmit rotary motion through a hermetically sealed wall. In operation a rotational torque is developed by the wobble plate.

  8. Donated Blood Won't Transmit Alzheimer's, Parkinson's Disease

    MedlinePlus

    ... fullstory_159577.html Donated Blood Won't Transmit Alzheimer's, Parkinson's Disease Swedish study of nearly 1.5 ... who have received blood transfusions from patients with Alzheimer's or Parkinson's disease," said Dr. Irving Gomolin, a ...

  9. Vibration causes acute vascular injury in a two-step process: vasoconstriction and vacuole disruption.

    PubMed

    Govindaraju, Sandya R; Bain, James Lw; Eddinger, Thomas J; Riley, Danny A

    2008-08-01

    Hand-arm vibration syndrome is a vasospastic and neurodegenerative occupational disease. In the current study, the mechanism of vibration-induced vascular smooth muscle cell (SMC) injury was examined in a rat-tail vibration model. Tails of male Sprague Dawley rats were vibrated continuously for 4 hr at 60 Hz, 49 m/s(2) with or without general anesthesia. Ventral tail arteries were aldehyde fixed and embedded in epoxy resin to enable morphological analysis. Vibration without anesthesia caused vasoconstriction and vacuoles in the SMC. Anesthetizing rats during vibration prevented vasoconstriction and vacuole formation. Exposing tail arteries in situ to 1 mM norepinephrine (NE) for 15 min induced the greatest vasoconstriction and vacuolation. NE induced vacuoles were twice as large as those formed during vibration. When vibrated 4 hr under anesthesia after pretreatment with NE for 15 min, the SMC lacked vacuoles and exhibited a longitudinal banding pattern of dark and light staining. The extracellular matrix was filled with particulates, which were confirmed by electron microscopy to be cellular debris. The present findings demonstrate that vibration-induced vasoconstriction (SMC contraction) requires functioning central nervous system reflexes, and the physical stress of vibration damages the contracted SMC by dislodging and fragmenting SMC vacuoles. PMID:18493932

  10. Cophasal horizontal wideband array antennas for transmitting with asymmetric output

    NASA Astrophysics Data System (ADS)

    Belousov, S. P.; Kliger, G. A.; Eskin, N. A.

    1985-03-01

    Type SGDRA cophasal horizontal wideband antennas for transmitters with asymmetric (single-stage) output are described. An antenna of this kind consists of rigid shunt vibrators and an asymmetric feeder channel. The latter is formed by symmetric overhead feeders, a symmetrizing device being available for operation with a single-stage transmitter. Two typical construction are: one tower section with four tiers of vibrator groups and two tower sections with eight tiers of vibrator groups on each, with an adapter from symmetric to asymmetric feeder channel in each case. Various arrangements for power feed are possible, coaxial cables being most suitable for this purpose. The performance characteristics of these antennas are discussed.

  11. Animal Communications Through Seismic Vibrations

    SciTech Connect

    Hill, Peggy

    2001-05-02

    Substrate vibration has been important to animals as a channel of communication for millions of years, but our literature on vibration in this context of biologically relevant information is only decades old. The jaw mechanism of the earliest land vertebrates allowed them to perceive substrate vibrations as their heads lay on the ground long before airborne sounds could be heard. Although the exact mechanism of vibration production and the precise nature of the wave produced are not always understood, recent development of affordable instrumentation to detect and measure vibrations has allowed researchers to answer increasingly sophisticated questions about how animals send and receive vibration signals. We now know that vibration provides information used in predator defense, prey detection, recruitment to food, mate choice, intrasexual competition, and maternal/brood social interactions in a variety of insect orders, spiders, crabs, scorpions, chameleons, frogs, golden moles, mole rats, kangaroos rats, wallabies, elephants and bison.

  12. Secure direct communication based on secret transmitting order of particles

    SciTech Connect

    Zhu Aidong; Zhang Shou; Xia Yan; Fan Qiubo

    2006-02-15

    We propose the schemes of quantum secure direct communication based on a secret transmitting order of particles. In these protocols, the secret transmitting order of particles ensures the security of communication, and no secret messages are leaked even if the communication is interrupted for security. This strategy of security for communication is also generalized to a quantum dialogue. It not only ensures the unconditional security but also improves the efficiency of communication.

  13. Surgical exposures of the hand.

    PubMed

    Watt, Andrew J; Chung, Kevin C

    2014-11-01

    Surgical approaches to the hand are commonly executed in the treatment of fractures, ligament injuries, and less commonly in the resection of bony tumors. Careful design and execution of these surgical approaches translates into superior functional and aesthetic outcomes. We have provided a thorough review of commonly used approaches to the hand by evaluating each of these approaches in the context of core principles including safety, versatility, preservation of stability, and aesthetic outcomes. PMID:25440073

  14. Ergonomic analysis of fastening vibration based on ISO Standard 5349 (2001).

    PubMed

    Joshi, Akul; Leu, Ming; Murray, Susan

    2012-11-01

    Hand-held power tools used for fastening operations exert high dynamic forces on the operator's hand-arm, potentially causing injuries to the operator in the long run. This paper presents a study that analyzed the vibrations exerted by two hand-held power tools used for fastening operations with the operating exhibiting different postures. The two pneumatic tools, a right-angled nut-runner and an offset pistol-grip, are used to install shearing-type fasteners. A tri-axial accelerometer is used to measure the tool's vibration. The position and orientation of the transducer mounted on the tool follows the ISO-5349 Standard. The measured vibration data is used to compare the two power tools at different operating postures. The data analysis determines the number of years required to reach a 10% probability of developing finger blanching. The results indicate that the pistol-grip tool induces more vibration in the hand-arm than the right-angled nut-runner and that the vibrations exerted on the hand-arm vary for different postures. PMID:22520174

  15. Thermoelastic vibration test techniques

    NASA Technical Reports Server (NTRS)

    Kehoe, Michael W.; Snyder, H. Todd

    1991-01-01

    The structural integrity of proposed high speed aircraft can be seriously affected by the extremely high surface temperatures and large temperature gradients throughout the vehicle's structure. Variations in the structure's elastic characteristics as a result of thermal effects can be observed by changes in vibration frequency, damping, and mode shape. Analysis codes that predict these changes must be correlated and verified with experimental data. The experimental modal test techniques and procedures used to conduct uniform, nonuniform, and transient thermoelastic vibration tests are presented. Experimental setup and elevated temperature instrumentation considerations are also discussed. Modal data for a 12 by 50 inch aluminum plate heated to a temperature of 475 F are presented. These data show the effect of heat on the plate's modal characteristics. The results indicated that frequency decreased, damping increased, and mode shape remained unchanged as the temperature of the plate was increased.

  16. Vibration-Response Analysis

    NASA Technical Reports Server (NTRS)

    Bowman, L. M.

    1986-01-01

    Dynamic behaviors of structures analyzed interactively. Interactive steadystate vibration-response program, VIBRA, developed. Frequency-response analyses commonly used in evaluating dynamic behaviors of structures subjected to cyclic external forces. VIBRA calculates frequency response using modalsuperposition approach. Method applicable to single or multiple forces applied to linear, proportionally damped structure in which damping is viscous or structural. VIBRA written in FORTRAN 77 for interactive execution.

  17. An ultrasonic ranging system for structural vibration measurements

    NASA Astrophysics Data System (ADS)

    Figueroa, Fernando; Barbieri, Enrique

    1991-08-01

    An ultrasonic ranging system (URS) that can be used to measure vibratory displacements in structures is described. A pair of ultrasonic transducers is used in a transmit-receive mode to acquire the motion of a point on a flexible structure. The structure's oscillating motion modulates the phase angle between the transmitted and received acoustic signals. A simple phase detector and low-pass filter combination demodulate the phase signal, thus extracting information about the motion of the point on the structure. The results reported concentrate on some design issues of the URS and its use as a potential displacement measuring device for flexible structures. The URS accurately distinguished four vibration frequencies of a simple cantilevered aluminum beam, with the highest frequency near 50 Hz.

  18. Estimate exchanger vibration

    SciTech Connect

    Nieh, C.D.; Zengyan, H.

    1986-04-01

    Based on the classical beam theory, a simple method for calculating the natural frequency of unequally spanned tubes is presented. The method is suitable for various boundary conditions. Accuracy of the calculations is sufficient for practical applications. This method will help designers and operators estimate the vibration of tubular exchangers. In general, there are three reasons why a tube vibrates in cross flow: vortex shedding, fluid elasticity and turbulent buffeting. No matter which is the cause, the basic reason is that the frequency of exciting force is approximately the same as or equal to the natural frequency of the tube. To prevent the heat exchanger from vibrating, it is necessary to select correctly the shell-side fluid velocity so that the frequency of exciting force is different from the natural frequency of the tube, or to vary the natural frequency of the heat exchanger tube. So precisely determining the natural frequency of the heat exchanger, especially its foundational frequency under various supporting conditions, is of significance.

  19. Vibrational stability of graphene

    NASA Astrophysics Data System (ADS)

    Hu, Yangfan; Wang, Biao

    2013-05-01

    The mechanical stability of graphene as temperature rises is analyzed based on three different self-consistent phonon (SCP) models. Compared with three-dimensional (3-D) materials, the critical temperature Ti at which instability occurs for graphene is much closer to its melting temperature Tm obtained from Monte Carlo simulation (Ti ≃ 2Tm, K. V. Zakharchenko, A. Fasolino, J. H. Los, and M. I. Katsnelson, J. Phys. Condens. Matter 23, 202202). This suggests that thermal vibration plays a significant role in melting of graphene while melting for 3-D materials is often dominated by topologic defects. This peculiar property of graphene derives from its high structural anisotropy, which is characterized by the vibrational anisotropic coefficient (VAC), defined upon its Lindermann ratios in different directions. For any carbon based material with a graphene-like structure, the VAC value must be smaller than 5.4 to maintain its stability. It is also found that the high VAC value of graphene is responsible for its negative thermal expansion coefficient at low temperature range. We believe that the VAC can be regarded as a new criterion concerning the vibrational stability of any low-dimensional (low-D) materials.

  20. Vibrational Dynamics of Tricyanomethanide

    NASA Astrophysics Data System (ADS)

    Weidinger, Daniel; Houchins, Cassidy; Owrutsky, Jeffrey C.

    2011-06-01

    Time-resolved and steady-state IR spectroscopy have been used to characterize vibrational spectra and energy relaxation dynamics of the CN stretching band of the tricyanomethanide (TCM, C(CN)3-) anion near 2170 Cm-1 in solutions of water, heavy water, methanol, formamide, dimethyl sulfoxide (DMSO) and the ionic liquid 1-butyl methyl imidazolium tetrafluoroborate ([BMIM][BF4]). The band intensity is strong (˜1500 M-1Cm-1) and the vibrational energy relaxation times are relatively long (˜5 ps in water, 12 ps in heavy water, and ˜30 ps in DMSO and [BMIM][BF4]). They are longer than those previously reported for dicyanamide in the same solvents. Although the static TCM frequency generally shifts to higher frequency with more strongly interacting solvents, the shift does not follow the same trend as the vibrational dynamics. The results for the experimental frequencies and intensities agree well with results from ab initio calculations. Proton and electron affinities for TCM are also calculated because they are relevant to potential applications of this anion in low viscosity ionic liquids.

  1. Vibration isolation mounting system

    NASA Technical Reports Server (NTRS)

    Carter, Sam D. (Inventor); Bastin, Paul H. (Inventor)

    1995-01-01

    A system is disclosed for mounting a vibration producing device onto a spacecraft structure and also for isolating the vibration forces thereof from the structure. The system includes a mount on which the device is securely mounted and inner and outer rings. The rings and mount are concentrically positioned. The system includes a base (secured to the structure) and a set of links which are interconnected by a set of torsion bars which allow and resist relative rotational movement therebetween. The set of links are also rotatably connected to a set of brackets which are rigidly connected to the outer ring. Damped leaf springs interconnect the inner and outer rings and the mount allow relative translational movement therebetween in X and Y directions. The links, brackets and base are interconnected and configured so that they allow and resist translational movement of the device in the Z direction so that in combination with the springs they provide absorption of vibrational energy produced by the device in all three dimensions while providing rotational stiffness about all three axes to prevent undesired rotational motions.

  2. Vibration mounts for noise and vibration control

    SciTech Connect

    Mullins, P.

    1995-04-01

    Isolating noise and vibration is of major importance in engine applications whether on board ship or land. Ulstein Bergen, for instance, has virtually standardized on Metalastik D Series mounts for its range of lean-burn, gas engines used in power generation and cogeneration plants. In the largest engine installations, the Metalastik suspension system can carry as much as 47 tons, total weight. The system is designed to isolate the forces generated by a three megawatt engine able to develop full power within 10 seconds of starting. In setups of this size, as many as 24 mounts are arranged underneath the baseplate of the power unit. Metalastik recently announced an entirely new and innovative mounting for marine applications. The new Cushymount K mounting incorporates four separate rubber/metal spring elements housed between top and bottom iron castings. The design combines three-way control of engine movement with relatively large deflection in the rubber. The new design is claimed to be robust and easy to install by means of four bolt holes on the top and bottom castings. Other recommended applications include compressors, exhaust gas silencers, refrigeration/air-conditioning plant and similar ancillary equipment. 2 figs.

  3. Hand pain other than carpal tunnel syndrome (CTS): the role of occupational factors.

    PubMed

    Andréu, José-Luis; Otón, Teresa; Silva-Fernández, Lucía; Sanz, Jesús

    2011-02-01

    Some occupational factors have been implicated in the development of disorders manifested as hand pain. The associations seem to be well documented in processes such as hand-arm vibration syndrome (HAVS) or writer's cramp. There are contradictory data in the literature about the relationships of trigger finger, De Quervain's tenosynovitis (DQT) and tenosynovitis of the wrist with occupational factors. In this article, we review current knowledge about clinical manifestations, case definition, implicated occupational factors, diagnosis and treatment of the most relevant hand pain disorders that have been associated with occupational factors, excluding carpal tunnel syndrome (CTS). PMID:21663848

  4. Topographic analysis of the skull vibration-induced nystagmus test with piezoelectric accelerometers and force sensors.

    PubMed

    Dumas, Georges; Lion, Alexis; Perrin, Philippe; Ouedraogo, Evariste; Schmerber, Sébastien

    2016-03-23

    Vibration-induced nystagmus is elicited by skull or posterior cervical muscle stimulations in patients with vestibular diseases. Skull vibrations delivered by the skull vibration-induced nystagmus test are known to stimulate the inner ear structures directly. This study aimed to measure the vibration transfer at different cranium locations and posterior cervical regions to contribute toward stimulus topographic optimization (experiment 1) and to determine the force applied on the skull with a hand-held vibrator to study the test reproducibility and provide recommendations for good clinical practices (experiment 2). In experiment 1, a 100 Hz hand-held vibrator was applied on the skull (vertex, mastoids) and posterior cervical muscles in 11 healthy participants. Vibration transfer was measured by piezoelectric sensors. In experiment 2, the vibrator was applied 30 times by two experimenters with dominant and nondominant hands on a mannequin equipped to measure the force. Experiment 1 showed that after unilateral mastoid vibratory stimulation, the signal transfer was higher when recorded on the contralateral mastoid than on the vertex or posterior cervical muscles (P<0.001). No difference was observed between the different vibratory locations when vibration transfer was measured on vertex and posterior cervical muscles. Experiment 2 showed that the force applied to the mannequin varied according to the experimenters and the handedness, higher forces being observed with the most experienced experimenter and with the dominant hand (10.3±1.0 and 7.8±2.9 N, respectively). The variation ranged from 9.8 to 29.4% within the same experimenter. Bone transcranial vibration transfer is more efficient from one mastoid to the other mastoid than other anatomical sites. The mastoid is therefore the optimal site for skull vibration-induced nystagmus test in patients with unilateral vestibular lesions and enables a stronger stimulation of the healthy side. In clinical practice

  5. Passive vibration isolation for SITELLE's closed cycle cooled cryostats

    NASA Astrophysics Data System (ADS)

    Baril, Marc; Benedict, Tom; Barrick, Gregory; Ho, Kevin

    2012-09-01

    The SITELLE Imaging Fourier Transform Spectrometer system being developed by l'Université Laval at ABB-Bomem will require two identical CCD detector systems. Our requirements for the cryogenic system for these cameras are: cooling to below 190 K, extremely low vibrational input from the cryogenic system (<1 mg RMS from 0-2 kHz), hands-off operation over long periods of time and low original capital outlay and continued operation cost. These constraints drove towards the selection of a Polycold PCC cooled system which exhibits relatively low vibrational noise and can efficiently achieve the required cooling power in our target temperature range. This paper will present work performed to passively mitigate high frequency vibrations imparted by the Polycold PCC cryo-head on the detector cryostat.

  6. Analysis of Hand and Wrist Postural Synergies in Tolerance Grasping of Various Objects.

    PubMed

    Liu, Yuan; Jiang, Li; Yang, Dapeng; Liu, Hong

    2016-01-01

    Human can successfully grasp various objects in different acceptable relative positions between human hand and objects. This grasp functionality can be described as the grasp tolerance of human hand, which is a significant functionality of human grasp. To understand the motor control of human hand completely, an analysis of hand and wrist postural synergies in tolerance grasping of various objects is needed. Ten healthy right-handed subjects were asked to perform the tolerance grasping with right hand using 6 objects of different shapes, sizes and relative positions between human hand and objects. Subjects were wearing CyberGlove attaching motion tracker on right hand, allowing a measurement of the hand and wrist postures. Correlation analysis of joints and inter-joint/inter-finger modules were carried on to explore the coordination between joints or modules. As the correlation between hand and wrist module is not obvious in tolerance grasping, individual analysis of wrist synergies would be more practical. In this case, postural synergies of hand and wrist were then presented separately through principal component analysis (PCA), expressed through the principal component (PC) information transmitted ratio, PC elements distribution and reconstructed angle error of joints. Results on correlation comparison of different module movements can be well explained by the influence factors of the joint movement correlation. Moreover, correlation analysis of joints and modules showed the wrist module had the lowest correlation among all inter-finger and inter-joint modules. Hand and wrist postures were both sufficient to be described by a few principal components. In terms of the PC elements distribution of hand postures, compared with previous investigations, there was a greater proportion of movement in the thumb joints especially the interphalangeal (IP) and opposition rotation (ROT) joint. The research could serve to a complete understanding of hand grasp, and the design

  7. Coping with Congenital Hand Differences

    PubMed Central

    Franzblau, Lauren E.; Chung, Kevin C.; Carlozzi, Noelle; Chin, Autumn Y. T.; Nellans, Kate W.; Waljee, Jennifer F.

    2015-01-01

    Purpose Although functional outcomes following reconstruction for congenital hand differences are frequently described, much less is known regarding children’s ability to cope with psychosocial effects of these conditions. We qualitatively explored stress and coping mechanisms among children following reconstructive surgery for congenital hand differences. Methods Forty patients and their parents participated in semi-structured interviews examining stress related to hand functioning and appearance, emotional responses to stress, and coping strategies. Interviews were audio-taped, transcribed, and analyzed thematically. A consensus taxonomy for classifying content evolved from comparisons of coding by two reviewers. Themes expressed by participants were studied for patterns of connection and grouped into broader categories. Results In this sample, 58% of children and 40% of parents reported stress related to congenital hand differences, attributed to functional deficits (61%), hand appearance (27%), social interactions (58%), and emotional reactions (46%). Among the 18 children who reported stress, 43% of parents were not aware of the presence of stress. Eight coping strategies emerged, including humor (12%), self-acceptance (21%), avoidance (27%), seeking external support (30%), concealment (30%), educating others (9%), support programs (21%) and religion (24%). Conclusions Although children with congenital hand differences often experience emotional stress related to functional limitations and aesthetic deformities, many apply positive coping mechanisms that enhance self-esteem and self-esteem. Clinicians caring for children with congenital hand differences should inform families about potential sources of stress in order to direct resources toward strengthening coping strategies and support systems. Level of Evidence Level IV-Case series PMID:25502854

  8. Smart mug to measure hand's geometrical mechanical impedance.

    PubMed

    Hondori, Hossein Mousavi; Tech, Ang Wei

    2011-01-01

    A novel device, which looks like a mug, has been proposed for measuring the impedance of human hand. The device is designed to have convenient size and light weight similar to an ordinary coffee mug. It contains a 2-axis inertia sensor to monitor vibration and a small motor to carry an eccentric mass (m=100 gr, r=2 cm, rpm=600). The centrifugal force due to the rotating mass applies a dynamic force to the hand that holds the mug. Correlation of the acceleration signals with the perturbing force gives the geometrical mechanical impedance. Experimental results on a healthy subject shows that impedance is posture dependant while it changes with the direction of the applied perturbing force. For nine postures the geometrical impedance is obtained all of which have elliptical shapes. The method can be used for assessment of spasticity and monitoring stability in patients with stroke or similar problems. PMID:22255230

  9. Mechanical impedances distributed at the fingers and palm of the human hand in three orthogonal directions

    NASA Astrophysics Data System (ADS)

    Dong, Ren G.; Welcome, Daniel E.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.; Wu, John Z.; Rakheja, Subhash

    2012-02-01

    The objective of this study is to investigate the basic characteristics of the three axis mechanical impedances distributed at the fingers and palm of the hand subjected to vibrations along three orthogonal directions ( xh, yh, and zh). Seven subjects participated in the experiment on a novel three-dimensional (3-D) hand-arm vibration test system equipped with a 3-D instrumented handle. The total impedance of the entire hand-arm system was obtained by performing a sum of the distributed impedances. Two major resonances were observed in the impedance data in each direction. For the hand forces (30 N grip and 50 N push) and body postures applied in this study, the first resonance was in the range of 20-40 Hz, and it was primarily observed in the impedance at the palm. The second resonance was generally observed in the impedance at the fingers, while the resonance frequency varied greatly with the subject and vibration direction, ranging from 100 to 200 Hz in the xh direction, 60 to 120 Hz in the yh direction, and 160 to 300 Hz in the zh direction. The impedance at the palm was greater than that at the fingers below a certain frequency in the range of 50-100 Hz, depending on the vibration direction. At higher frequencies, however, the impedance magnitude at the fingers either approached or exceeded that at the palm. The impedance in the zh direction was generally higher than those in the other directions, but it became comparable with that in the xh direction at frequencies above 250 Hz, while the impedance in the yh direction was the lowest. The frequency dependencies of the vibration power absorptions for the entire hand-arm system in the three directions were different, but their basic trends were similar to that of the frequency weighting defined in the current ISO standard. The implications of the results are discussed.

  10. The effects of low-frequency vibrations on hepatic profile of blood

    NASA Astrophysics Data System (ADS)

    Damijan, Z.

    2008-02-01

    Body vibrations training has become popular in sports training, fitness activity, it is still a rare form of physical rehabilitation.. Vibrations are transmitted onto the whole body or some body parts of an exercising person via a vibration platform subjected to mechanical vertical vibrations. During the training session a participant has to maintain his body position or do exercises that engage specific muscles whilst vibrations of the platform are transmitted onto the person's body. This paper is the continuation of the earlier study covering the effects of low-frequency vibrations on selected physiological parameters of the human body. The experiments were conducted to find the answer to the question if vibration exposure (total duration of training sessions 6 hours 20 min) should produce any changes in hepatic profile of blood. Therefore a research program was undertaken at the University of Science and Technology AGH UST to investigate the effects of low-frequency vibration on selected parameters of hepatic profile of human blood. Cyclic fluctuations of bone loading were induced by the applied harmonic vibration 3.5 Hz and amplitude 0.004 m. The experiments utilizing two vibrating platforms were performed in the Laboratory of Structural Acoustics and Biomedical Engineering AGH-UST. The applied vibrations were harmless and not annoying, in accordance with the standard PN-EN ISO 130901-1, 1998. 23 women volunteers had 19 sessions on subsequent working days, at the same time of day. during the tests the participants remained in the standing position, passive. The main hypothesis has it that short-term low-frequency vibration exposure might bring about the changes of the hepatic profile of blood, including: bilirubin (BILIRUBIN), alkaline phosphatase (Alp), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and albumin (ALBUMIN) levels. Research data indicate the low-frequency vibrations exposure produces statistically significant decrease of

  11. Nonlinear effects contributing to hand-stopping tones in a horn.

    PubMed

    Ebihara, Takayasu; Yoshikawa, Shigeru

    2013-05-01

    Hand stopping is a technique for playing the French horn while closing the bell relatively tightly using the right hand. The resulting timbre is called "penetrating" and "metallic." The effect of hand stopping on the horn input impedance has been studied, but the tone quality has hardly ever been considered. In the present paper, the dominant physical cause of the stopped-tone quality is discussed in detail. Numerical calculations of the transmission function of the stopped-horn model and the measurements of both sound pressure and wall vibration in hand stopping are carried out. They strongly suggest that the metallicness of the stopped tone is characterized by the generation of higher harmonics extending over 10 kHz due to the rapidly corrugating waveform and that the associated wall vibration on the bell may be responsible for this higher harmonic generation. However, excitation experiments and immobilization experiments performed to elucidate the relationship between sound radiation and wall vibration deny their correlation. Instead, the measurement result of the mouthpiece pressure in hand stopping suggests that minute wave corrugations peculiar to the metallic stopped tones are probably formed by nonlinear sound propagation along the bore. PMID:23654412

  12. Need for and benefits of launch vibration isolation

    NASA Astrophysics Data System (ADS)

    Bicos, Andrew S.; Johnson, Conor D.; Davis, L. Porter

    1997-05-01

    Spacecraft designs are driven by the necessity of the spacecraft to survive being launched into orbit. This launch environment consists of structure-borne vibrations transmitted to the payload through the payload attach fitting (PAF) and acoustic excitation. Here we present a discussion on the need for and benefit of isolating the structure-borne vibrations. If the PAF were replaced with an isolator with the correct characteristics the potential benefits would be significant. These benefits include reduced spacecraft structural weight and cost, as well as increased life and reliability. This paper presents an overview of the problem of vibration on a launch vehicle payload and the benefits that an isolating PAF would provide. The structure-borne vibrations experienced by a spacecraft during launch are made up of transient, shock, and periodic oscillations originating in the engines, pyrotechnic separation systems, and from aerodynamic loading. Any isolation system used by the launch vehicle must satisfy critical launch vehicle constraints on weight, cost, and rattle space. A discussion of these points is presented from the perspective of both a launch vehicle manufacturer and a spacecraft manufacturer/user.

  13. Polyvinylidene fluoride (PVDF) vibration sensor for stethoscope and contact microphones

    NASA Astrophysics Data System (ADS)

    Toda, Minoru; Thompson, Mitchell

    2005-09-01

    This paper describes a new type of contact vibration sensor made by bonding piezoelectric PVDF film to a curved frame structure. The concave surface of the film is bonded to a rubber piece having a front contact face. Vibration is transmitted from this face through the rubber to the surface of the PVDF film. Pressure normal to the surface of the film is converted to circumferential strain, and an electric field is induced by the piezoelectric effect. The frequency response of the device was measured using an accelerometer mounted between the rubber face and a rigid vibration exciter plate. Sensitivity (voltage per unit displacement) was deduced from the device output and measured acceleration. The sensitivity was flat from 16 Hz to 3 kHz, peaking at 6 kHz due to a structural resonance. Calculations predicting performance against human tissue (stethoscope or contact microphone) show results similar to data measured against the metal vibrator. This implies that an accelerometer can be used for calibrating a stethoscope or contact microphone. The observed arterial pulse waveform showed more low-frequency content than a conventional electronic stethoscope.

  14. Ground vibration generated by trains in underground tunnels

    NASA Astrophysics Data System (ADS)

    Forrest, J. A.; Hunt, H. E. M.

    2006-07-01

    A popular method used to reduce vibration transmitted from underground railways into nearby buildings is floating-slab track, whereby a concrete slab supporting the two rails is mounted on rubber bearings or steel springs to isolate it from the tunnel invert. This paper adds a track model to a previously developed three-dimensional tunnel model in order to assess the effectiveness of floating-slab track. A slab beam coupled to the tunnel in the wavenumber domain, with the slab bearings represented by an elastic layer, is examined first. A second beam representing the two rails together is then coupled to the slab, and axle masses representing a train are added to the rail beam. Power-spectral densities and RMS levels of soil vibration due to random roughness-displacement excitation between the masses and the rail beam are calculated. Analytical techniques are used to minimise the computational requirements of the model. The results demonstrate the inadequacy of simple mass-spring and Winkler-beam models with rigid foundations for the assessment of the vibration-isolation performance of railway track. They suggest that the achievable insertion loss is modest and that floating the track slab may in fact cause increased transmission of vibration under certain conditions.

  15. Possible solutions to mitigate vibration effects in laser intersatellite links

    NASA Astrophysics Data System (ADS)

    Shlomi, Arnon; Kopeika, Norman S.

    2002-01-01

    Free space laser communication between satellites networked together can facilitate high-speed communication between different places on earth. The advantages of an optical communication system by comparison with a microwave communication system in free space are: a) smaller size and weight, b) less transmitter power, c) larger bandwidth, d) higher immunity to interference, and e) smaller transmitter beam divergence. The use of optical radiation as a carrier between the satellites engenders very narrow beam divergence angles. Due to the narrow beam divergence angle and the large distance between the satellites, the pointing from one satellite to another is complicated. The problem is further complicated due to vibrations of the pointing system caused by two fundamental mechanisms, stochastic in nature; 1) tracking nose created by the electro-optic tracker and 2) vibrations created by internal and external mechanical mechanisms. The vibrations displace the transmitted beam and the receiver field of view with respect to one another. Such movement decreases the average received signal, and increases the bit error rate (BER). In this paper we will review five methods to mitigate the effect of vibrations on laser satellite communication system. The methods are a) receiver with adaptive detector arrays, b) Bandwidth/data rate/coding rate adaptation, c) Power minimization using adaptive beam-width, d) Communication diversity within the satellite network, and e) Power control.

  16. Automatic Generation of Analytic Equations for Vibrational and Rovibrational Constants from Fourth-Order Vibrational Perturbation Theory

    NASA Astrophysics Data System (ADS)

    Matthews, Devin A.; Gong, Justin Z.; Stanton, John F.

    2014-06-01

    The derivation of analytic expressions for vibrational and rovibrational constants, for example the anharmonicity constants χij and the vibration-rotation interaction constants α^B_r, from second-order vibrational perturbation theory (VPT2) can be accomplished with pen and paper and some practice. However, the corresponding quantities from fourth-order perturbation theory (VPT4) are considerably more complex, with the only known derivations by hand extensively using many layers of complicated intermediates and for rotational quantities requiring specialization to orthorhombic cases or the form of Watson's reduced Hamiltonian. We present an automatic computer program for generating these expressions with full generality based on the adaptation of an existing numerical program based on the sum-over-states representation of the energy to a computer algebra context. The measures taken to produce well-simplified and factored expressions in an efficient manner are discussed, as well as the framework for automatically checking the correctness of the generated equations.

  17. A comparison of different vibration exercise techniques on neuromuscular performance.

    PubMed

    García-Gutiérrez, M T; Rhea, M R; Marín, P J

    2014-09-01

    The first purpose of this study was to determine the effects of whole-body vibration (WBV) exercise during an isometric hand-grip exercise. The second purpose was to evaluate whether more than one vibratory focus would evoke an increase in the effects evoked by only one vibratory focus. The present study investigated whether WBV exposure during 10 repetitions of a handgrip dynamometer while standing on a WBV platform. Twenty-eight recreationally active university students completed 3 different test conditions, in random order: 1) grip dynamometer exercise with superimposed WBV and contralateral arm vibration (WBV+AV); 2) superimposed arm vibration only (AV); 3) grip dynamometer exercise without vibration (Control). The hand grip strength was slightly higher in the WBV condition as compared to the Control and AV conditions (1.1% and 3.6%, p>0.05, respectively). A main effect of the EMGrms of extensor digitorum muscle (ED) was observed indicating that the WBV+AV condition produced a lower co-activation of ED during a flexor digital task than the Control and AV (p<0.05) conditions. The application of WBV+AV may acutely increase muscle coordination and decreases the coactivation of ED. Furthermore, the muscle EMGrms showed increases in activation near the vibratory focus in both upper- and lower-body. PMID:25198225

  18. Variable-Tension-Cord Suspension/Vibration-Isolation System

    NASA Technical Reports Server (NTRS)

    Villemarette, Mark L.; Boston, Joshua; RInks, Judith; Felice, Pat; Stein, Tim; Payne, Patrick

    2006-01-01

    A system for mechanical suspension and vibration isolation of a machine or instrument is based on the use of Kevlar (or equivalent aromatic polyamide) cord held in variable tension between the machine or instrument and a surrounding frame. The basic concept of such a tensioned-cord suspension system (including one in which the cords are made of aromatic polyamide fibers) is not new by itself; what is new here is the additional provision for adjusting the tension during operation to optimize vibration- isolation properties. In the original application for which this system was conceived, the objective is to suspend a reciprocating cryocooler aboard a space shuttle and to prevent both (1) transmission of launch vibrations to the cryocooler and (2) transmission of vibrations from the cryocooler to samples in a chamber cooled by the cryocooler. The basic mechanical principle of this system can also be expected to be applicable to a variety of other systems in which there are requirements for cord suspension and vibration isolation. The reciprocating cryocooler of the original application is a generally axisymmetric object, and the surrounding frame is a generally axisymmetric object with windows (see figure). Two cords are threaded into a spoke-like pattern between attachment rings on the cryocooler, holes in the cage, and cord-tension- adjusting assemblies. Initially, the cord tensions are adjusted to at least the level necessary to suspend the cryocooler against gravitation. Accelerometers for measuring vibrations are mounted (1) on the cold tip of the cryocooler and (2) adjacent to the cage, on a structure that supports the cage. During operation, a technician observes the accelerometer outputs on an oscilloscope while manually adjusting the cord tensions in an effort to minimize the amount of vibration transmitted to and/or from the cryocooler. A contemplated future version of the system would include a microprocessor-based control subsystem that would include cord

  19. [Hand hygiene: revolution and globalization].

    PubMed

    Pittet, Didier

    2009-04-01

    Hand hygiene is the primary measure to prevent healthcare-associated infections and the spread of antimicrobial resistance. Low staff compliance remains a major problem. Successful promotion requires a multimodal strategy. The World Health Organization (WHO) proposes an approach including at least five components: system change, in particular the recourse to alcohol-based hand rubbing as the new standard of care, staff education using newly developed tools, monitoring and feedback of staff performance, reminders in the workplace, and promotion of an institutional safety climate. Patient participation in hand hygiene promotion is under testing. Early results of the strategy tested in a large number of healthcare settings in both limited- and high-resource countries are extremely encouraging. PMID:19492514

  20. Hand-Based Biometric Analysis

    NASA Technical Reports Server (NTRS)

    Bebis, George

    2013-01-01

    Hand-based biometric analysis systems and techniques provide robust hand-based identification and verification. An image of a hand is obtained, which is then segmented into a palm region and separate finger regions. Acquisition of the image is performed without requiring particular orientation or placement restrictions. Segmentation is performed without the use of reference points on the images. Each segment is analyzed by calculating a set of Zernike moment descriptors for the segment. The feature parameters thus obtained are then fused and compared to stored sets of descriptors in enrollment templates to arrive at an identity decision. By using Zernike moments, and through additional manipulation, the biometric analysis is invariant to rotation, scale, or translation or an input image. Additionally, the analysis uses re-use of commonly seen terms in Zernike calculations to achieve additional efficiencies over traditional Zernike moment calculation.

  1. Hand-Based Biometric Analysis

    NASA Technical Reports Server (NTRS)

    Bebis, George (Inventor); Amayeh, Gholamreza (Inventor)

    2015-01-01

    Hand-based biometric analysis systems and techniques are described which provide robust hand-based identification and verification. An image of a hand is obtained, which is then segmented into a palm region and separate finger regions. Acquisition of the image is performed without requiring particular orientation or placement restrictions. Segmentation is performed without the use of reference points on the images. Each segment is analyzed by calculating a set of Zernike moment descriptors for the segment. The feature parameters thus obtained are then fused and compared to stored sets of descriptors in enrollment templates to arrive at an identity decision. By using Zernike moments, and through additional manipulation, the biometric analysis is invariant to rotation, scale, or translation or an in put image. Additionally, the analysis utilizes re-use of commonly-seen terms in Zernike calculations to achieve additional efficiencies over traditional Zernike moment calculation.

  2. Snowblower injuries to the hand.

    PubMed

    Dietzel, D P; Gorosh, J; Burke, E F; Singer, R M

    1997-12-01

    We retrospectively reviewed the records of 62 patients who sustained serious hand injuries caused by snowblowers between 1981 and 1990. Frequency of injuries to digits tended to correlate with length (i.e., middle, index, ring, or small finger or thumb). Damage to tendons did not seem to follow any particular pattern. The majority of victims sustained multiple digital involvement. Complete versus partial amputation followed the same length distribution as did injured digits. Most of the injuries occurred to the dominant hand. When patients were further questioned regarding the circumstances and events leading to their injury, a recurring pattern was found. Most patients described a wet, heavy snow having recently fallen. The majority of the patients who were injured by placing their hands into the exit chute admitted that they were aware the machine was running, but thought that they had a greater clearance to the rotating impeller blade. PMID:9413590

  3. 38 CFR 4.69 - Dominant hand.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Dominant hand. 4.69... DISABILITIES Disability Ratings The Musculoskeletal System § 4.69 Dominant hand. Handedness for the purpose of.... Only one hand shall be considered dominant. The injured hand, or the most severely injured hand, of...

  4. 38 CFR 4.69 - Dominant hand.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Dominant hand. 4.69... DISABILITIES Disability Ratings The Musculoskeletal System § 4.69 Dominant hand. Handedness for the purpose of.... Only one hand shall be considered dominant. The injured hand, or the most severely injured hand, of...

  5. 38 CFR 4.69 - Dominant hand.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Dominant hand. 4.69... DISABILITIES Disability Ratings The Musculoskeletal System § 4.69 Dominant hand. Handedness for the purpose of.... Only one hand shall be considered dominant. The injured hand, or the most severely injured hand, of...

  6. 38 CFR 4.69 - Dominant hand.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Dominant hand. 4.69... DISABILITIES Disability Ratings The Musculoskeletal System § 4.69 Dominant hand. Handedness for the purpose of.... Only one hand shall be considered dominant. The injured hand, or the most severely injured hand, of...

  7. 38 CFR 4.69 - Dominant hand.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Dominant hand. 4.69... DISABILITIES Disability Ratings The Musculoskeletal System § 4.69 Dominant hand. Handedness for the purpose of.... Only one hand shall be considered dominant. The injured hand, or the most severely injured hand, of...

  8. Impacts of structural vibration on the performance of ultrasound sensor networks powered by vibration-harvested energy

    NASA Astrophysics Data System (ADS)

    Das, Saptarshi; Shi, Yan; Dong, Bo; Biswas, Subir

    2016-04-01

    This paper develops an energy-aware ultrasonic sensor network architecture using a Pulse Switching approach for lightweight, through-substrate operation in Structural Health Monitoring applications. Pulse Switching protocols employ single pulses instead of multi-bit packets for information delivery with maximal lightness in event monitoring with binary sensing requirements i.e. where event information transmitted is only a single bit (YES / NO) based on evaluation of structural characteristics. The paper presents a simulation study of the Energy-Aware Through-Substrate Pulse Switching protocol performance for structural monitoring when operated using energy harvested from intermittent vibrations in the structure itself. The paper incorporates an energy harvesting model for simulating memory-less vibration patterns using exponentially distributed random processes at different networked nodes. These nodes are placed inside a rectangular plate structure and the corresponding harvested energy profiles are simulated. The vibration profiles are a function of the position of the node on the plate as well as time. Such spatio-temporal variation leads to interesting dynamics in the energy-aware protocol operation which have been explored in the current paper setting. Through the simulations, it is shown that the proposed Energy-Aware Pulse Switching protocol mechanisms can offer a robust through-substrate network that can be reliably used for Structural Health Monitoring using vibration-harvested energy.

  9. Lionfish envenomation of the hand.

    PubMed

    Patel, M R; Wells, S

    1993-05-01

    Lionfish (Pterois volitans) envenomation of the hand causes excruciating pain and occurs in three grades: (1) erythematous reaction, (2) blister formation, and (3) dermal necrosis. The initial treatment in all cases is to soak the hand in nonscalding water (45 degrees C) until the pain subsides by denaturing the thermolabile venom proteins. The blisters should be immediately excised to prevent dermal necrosis, inasmuch as the blister fluid contains residual active venom. To prevent a hypersensitivity reaction, any further contact with the fish should be avoided. PMID:8515029

  10. Predicting hand function after hemidisconnection.

    PubMed

    Küpper, Hanna; Kudernatsch, Manfred; Pieper, Tom; Groeschel, Samuel; Tournier, Jacques-Donald; Raffelt, David; Winkler, Peter; Holthausen, Hans; Staudt, Martin

    2016-09-01

    Hemidisconnections (i.e. hemispherectomies or hemispherotomies) invariably lead to contralateral hemiparesis. Many patients with a pre-existing hemiparesis, however, experience no deterioration in motor functions, and some can still grasp with their paretic hand after hemidisconnection. The scope of our study was to predict this phenomenon. Hypothesizing that preserved contralateral grasping ability after hemidisconnection can only occur in patients controlling their paretic hands via ipsilateral corticospinal projections already in the preoperative situation, we analysed the asymmetries of the brainstem (by manual magnetic resonance imaging volumetry) and of the structural connectivity of the corticospinal tracts within the brainstem (by magnetic resonance imaging diffusion tractography), assuming that marked hypoplasia or Wallerian degeneration on the lesioned side in patients who can grasp with their paretic hands indicate ipsilateral control. One hundred and two patients who underwent hemidisconnections between 0.8 and 36 years of age were included. Before the operation, contralateral hand function was normal in 3/102 patients, 47/102 patients showed hemiparetic grasping ability and 52/102 patients could not grasp with their paretic hands. After hemidisconnection, 20/102 patients showed a preserved grasping ability, and 5/102 patients began to grasp with their paretic hands only after the operation. All these 25 patients suffered from pre- or perinatal brain lesions. Thirty of 102 patients lost their grasping ability. This group included all seven patients with a post-neonatally acquired or progressive brain lesion who could grasp before the operation, and also all three patients with a preoperatively normal hand function. The remaining 52/102 patients were unable to grasp pre- and postoperatively. On magnetic resonance imaging, the patients with preserved grasping showed significantly more asymmetric brainstem volumes than the patients who lost their grasping

  11. Toe-to-hand transfer.

    PubMed

    Yoshimura, M

    1980-07-01

    Toe-to-hand transfer was performed in 28 patients, involving 33 fingers, using microvascular technique. Of this number, 26 patients (31 fingers) had experienced trauma, and the remaining 2 patients (2 fingers) had a congenital deformity. The toew used for grafting were the great toe (1), the second tow (30), and third toe (2). Success was achieved in all cases, sensory recovery was good, and remarkable improvement was attained in function and cosmetic appearance. Metacarpal hand, amputation of thumb, and amputation thumb and three fingers were good indications for this procedure, which gave satisfactory aesthetic results, even in patients with amputation of single digits. PMID:7394050

  12. Compound hydraulic seismic source vibrator

    SciTech Connect

    Myers, W.J.

    1989-12-05

    This patent describes a compound seismic source vibrator. It comprises: a housing having an upper section and a low frequency radiating section; a low frequency means for vibrating the low frequency radiating section; a high frequency radiating section flexibly connected to the low frequency radiating section; and a high frequency means rigidly secured to the low frequency radiating section for separately vibrating the high frequency radiating section.

  13. Flow-induced vibrations-1987

    SciTech Connect

    Au-Yang, M.K.; Chen, S.S.

    1987-01-01

    This book contains 20 selections. Some of the titles are: Acoustic resonance in heat exchanger tube bundles--Part 1. Physical nature of the phenomenon; Theoretical and experimental studies on heat exchanger U-bend tube bundle vibration characteristics; Experimental model analysis of metallic pipeline conveying fluid; Leakage flow-induced vibration of an eccentric tube-in-tube slip joint; and A study on the vibrations of pipelines caused by internal pulsating flows.

  14. Torsional vibration of aircraft engines

    NASA Technical Reports Server (NTRS)

    Lurenbaum, Karl

    1932-01-01

    Exhaustive torsional-vibration investigations are required to determine the reliability of aircraft engines. A general outline of the methods used for such investigations and of the theoretical and mechanical means now available for this purpose is given, illustrated by example. True vibration diagrams are usually obtained from vibration measurements on the completed engine. Two devices for this purpose and supplementing each other, the D.V.L. torsiograph and the D.V.L. torsion recorder, are described in this report.

  15. Vibration damping method and apparatus

    DOEpatents

    Redmond, James M.; Barney, Patrick S.; Parker, Gordon G.; Smith, David A.

    1999-01-01

    The present invention provides vibration damping method and apparatus that can damp vibration in more than one direction without requiring disassembly, that can accommodate varying tool dimensions without requiring re-tuning, and that does not interfere with tool tip operations and cooling. The present invention provides active dampening by generating bending moments internal to a structure such as a boring bar to dampen vibration thereof.

  16. Vibration damping method and apparatus

    DOEpatents

    Redmond, J.M.; Barney, P.S.; Parker, G.G.; Smith, D.A.

    1999-06-22

    The present invention provides vibration damping method and apparatus that can damp vibration in more than one direction without requiring disassembly, that can accommodate varying tool dimensions without requiring re-tuning, and that does not interfere with tool tip operations and cooling. The present invention provides active dampening by generating bending moments internal to a structure such as a boring bar to dampen vibration thereof. 38 figs.

  17. Electrically evoked reticular lamina and basilar membrane vibrations in mice with alpha tectorin C1509G mutation

    NASA Astrophysics Data System (ADS)

    Ren, Tianying; He, Wenxuan

    2015-12-01

    Mechanical coupling between the tectorial membrane and the hair bundles of outer hair cells is crucial for stimulating mechanoelectrical transduction channels, which convert sound-induced vibrations into electrical signal, and for transmitting outer hair cell-generated force back to the basilar membrane to boost hearing sensitivity. It has been demonstrated that the detached tectorial membrane in mice with C1509G alpha tectorin mutation caused hearing loss, but enhanced electrically evoked otoacoustic emissions. To understand how the mutated cochlea emits sounds, the reticular lamina and basilar membrane vibrations were measured in the electrically stimulated cochlea in this study. The results showed that the electrically evoked basilar membrane vibration decreased dramatically while the reticular lamina vibration and otoacoustic emissions exhibited no significant change in C1509G mutation mice. This result indicates that a functional cochlear amplifier and a normal basilar membrane vibration are not required for the outer hair cell-generated sound to exit the cochlea.

  18. Computer analysis of railcar vibrations

    NASA Technical Reports Server (NTRS)

    Vlaminck, R. R.

    1975-01-01

    Computer models and techniques for calculating railcar vibrations are discussed along with criteria for vehicle ride optimization. The effect on vibration of car body structural dynamics, suspension system parameters, vehicle geometry, and wheel and rail excitation are presented. Ride quality vibration data collected on the state-of-the-art car and standard light rail vehicle is compared to computer predictions. The results show that computer analysis of the vehicle can be performed for relatively low cost in short periods of time. The analysis permits optimization of the design as it progresses and minimizes the possibility of excessive vibration on production vehicles.

  19. Resonance vibrations of aircraft propellers

    NASA Technical Reports Server (NTRS)

    Liebers, Fritz

    1932-01-01

    On the basis of the consideration of various possible kinds of propeller vibrations, the resonance vibrations caused by unequal impacts of the propeller blades appear to be the most important. Their theoretical investigation is made by separate analysis of torsional and bending vibrations. This method is justified by the very great difference in the two natural frequencies of aircraft propeller blades. The calculated data are illustrated by practical examples. Thereby the observed vibration phenomenon in the given examples is explained by a bending resonance, for which the bending frequency of the propeller is equal to twice the revolution speed.

  20. Mobile high frequency vibrator system

    SciTech Connect

    Fair, D.W.; Buller, P.L.

    1985-01-08

    A carrier mounted seismic vibrator system that is primarily adapted for generation of high force, high frequency seismic energy into an earth medium. The apparatus includes first and second vibrators as supported by first and second lift systems disposed in tandem juxtaposition generally centrally in said vehicle, and the lift systems are designed to maintain equal hold-down force on the vibrator coupling baseplates without exceeding the weight of the carrier vehicle. The juxtaposed vibrators are then energized in synchronized relationship to propagate increased amounts of higher frequency seismic energy into an earth medium.

  1. Measuring Vibrations With Nonvibration Sensors

    NASA Technical Reports Server (NTRS)

    Hill, Arthur J.

    1988-01-01

    Information about vibrations of structure and/or of nonvibration sensor attached to structure extracted from output of sensor. Sensor operated in usual way except, output fed to power-spectral-density analyzer. Vibrational components easily distinguishable in analyzer output because they have frequencies much higher than those of more-slowly-varying temperature, pressure, or other normally desired components. Spectral-analysis technique applied successfully to high-frequency resistance changes in output of platinum-wire resistance thermometer: vibrational peaks in resistance frequency spectrum confirmed by spectrum from accelerometer. Technique also showed predicted 17-kHz vibrational resonance in strain-guage-supporting beam in pressure sensor.

  2. Chaotic vortex induced vibrations

    SciTech Connect

    Zhao, J.; Sheridan, J.; Leontini, J. S.; Lo Jacono, D.

    2014-12-15

    This study investigates the nature of the dynamic response of an elastically mounted cylinder immersed in a free stream. A novel method is utilized, where the motion of the body during a free vibration experiment is accurately recorded, and then a second experiment is conducted where the cylinder is externally forced to follow this recorded trajectory. Generally, the flow response during both experiments is identical. However, particular regimes exist where the flow response is significantly different. This is taken as evidence of chaos in these regimes.

  3. Structural Acoustics and Vibrations

    NASA Astrophysics Data System (ADS)

    Chaigne, Antoine

    This chapter is devoted to vibrations of structures and to their coupling with the acoustic field. Depending on the context, the radiated sound can be judged as desirable, as is mostly the case for musical instruments, or undesirable, like noise generated by machinery. In architectural acoustics, one main goal is to limit the transmission of sound through walls. In the automobile industry, the engineers have to control the noise generated inside and outside the passenger compartment. This can be achieved by means of passive or active damping. In general, there is a strong need for quieter products and better sound quality generated by the structures in our daily environment.

  4. Turbine blade vibration dampening

    DOEpatents

    Cornelius, C.C.; Pytanowski, G.P.; Vendituoli, J.S.

    1997-07-08

    The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass ``M`` or combined mass ``CM`` of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics. 5 figs.

  5. Turbine blade vibration dampening

    DOEpatents

    Cornelius, Charles C.; Pytanowski, Gregory P.; Vendituoli, Jonathan S.

    1997-07-08

    The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass "M" or combined mass "CM" of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics.

  6. Evaluation of plasma-based transmit coils for magnetic resonance.

    PubMed

    Webb, A G; Aussenhofer, S A

    2015-12-01

    In this work a new concept for designing transmit coils for magnetic resonance using a plasma is introduced. Unlike conventional coils, a plasma can be turned on and off, eliminating electrical interactions between coils, and enabling radiofrequency-invisibility when desired. A surfatron has been designed to produce a surface-mode wave which propagates along the inner surface of a commercial fluorescent lighting tube. NMR spectra and images have been produced using the plasma as the transmit coil and a copper-based monopole to receive the signal. The transmit efficiency of the plasma tube was estimated, and is currently much lower than that of an equivalently-sized metal-based structure: however, there are many potential methods for increasing the efficiency using a custom-built plasma tube. PMID:26529202

  7. Paper area density measurement from forward transmitted scattered light

    DOEpatents

    Koo, Jackson C.

    2001-01-01

    A method whereby the average paper fiber area density (weight per unit area) can be directly calculated from the intensity of transmitted, scattered light at two different wavelengths, one being a non-absorpted wavelength. Also, the method makes it possible to derive the water percentage per fiber area density from a two-wavelength measurement. In the optical measuring technique optical transmitted intensity, for example, at 2.1 microns cellulose absorption line is measured and compared with another scattered, optical transmitted intensity reference in the nearby spectrum region, such as 1.68 microns, where there is no absorption. From the ratio of these two intensities, one can calculate the scattering absorption coefficient at 2.1 microns. This absorption coefficient at this wavelength is, then, experimentally correlated to the paper fiber area density. The water percentage per fiber area density can be derived from this two-wavelength measurement approach.

  8. Relaxation behavior measuring of transmitted light through ferrofluids film

    NASA Astrophysics Data System (ADS)

    Li, J.; Liu, X.-D.; Lin, Y.-Q.; Huang, Y.; Bai, L.

    2006-01-01

    In this paper, relaxation behavior of transmitted light through thin ferrofluid film under an applied magnetic field is measured. The results show that the intensity of transmitted light through a ferrofluid film increases quickly as soon as an external magnetic field is applied then weakens with time. If uniformity of the field is poor, the transmission of light continuously decreases in a measured duration. Otherwise, the transmission of light will tend increasingly towards a stable value after it decreases to a minimum value while the gradient of the field is low. The relaxation time would increase to an order of some hundreds seconds magnitude and is dependent on the strength of magnetic field and viscosity of the ferrofluids. The field-induced relaxation behaviors of transmitted light through ferrofluids correspond to anisotropic microstructure of the ferrofluids under applied magnetic field.

  9. Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces

    PubMed Central

    Conrad, Megan O.; Gadhoke, Bani; Scheidt, Robert A.; Schmit, Brian D.

    2015-01-01

    Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

  10. Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces.

    PubMed

    Conrad, Megan O; Gadhoke, Bani; Scheidt, Robert A; Schmit, Brian D

    2015-01-01

    Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

  11. Free-space optical communication satellite networks-vibration effects and possible solutions

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi; Kopeika, Norman S.

    1997-07-01

    A number of serious consortiums develop satellite communication networks. The objective of these communication projects is to service personal communication users almost everywhere on earth. The inter satellite links in those project use microwave radiation as the carrier. Free space optical communication between satellites networked together can make possible high speed communications between different places on earth. The advantages of an optical communication system instead of a microwave communication system in free space are: (1) smaller size and weight, (2) less transmitter power, (3) larger bandwidth, (4) higher immunity to interference, and (5) smaller transmitter beam divergence. The use of optical radiation as a carrier between the satellites creates very narrow beam divergence angles. Due to the narrow beam divergence angle and the large distance between the satellites the pointing from one satellite to another is complicated. The problem is more complicated due to vibration of the pointing system caused by two stochastic fundamental mechanisms (1) tracking noise created by the electrooptic tracker and (2) vibrations created by internal and external mechanical mechanisms. The vibrations displace the transmitted beam in the receiver plane. Such movement of the transmitted beam in the receiver plane decreases the average received signal which decreases increases the bit error rate. In this paper we review: (1) the present status of satellite networks, (2) developing efforts of optical satellite communication around the world, (3) performance results of vibration effects on different kinds of optical communication satellite networks and (4) seven approaches to overcome the problems caused by transmitter pointing vibration.

  12. American Society for Surgery of the Hand

    MedlinePlus

    ... Welcome to ASSH.org Home of the American Society for Surgery of the Hand. The American Society for Surgery of the Hand is the oldest and most prestigious medical society dedicated to the hand and upper extremity. Our ...

  13. Why Am I Left-Handed?

    MedlinePlus

    ... does since most hitters are right-handed. In basketball and other sports, a left-handed player can ... change in strategy. For instance, a left-handed basketball player will dribble with his or her left ...

  14. Clean Hands Save Lives: Emergency Situations

    MedlinePlus

    ... germs on hands varies by product. Washing with soap and water Place your hands together under water ( ... hands together for at least 20 seconds (with soap if possible). Wash all surfaces well, including wrists, ...

  15. Hand injury and electrical tools.

    PubMed

    Barton, A J

    1998-01-01

    This case study looks at an electrician who sustained two hand injuries due to tool use. The first injury was a ganglionic cyst in the right palm and the second was a cyst in the right thumb. Recommendations from The Job Accommodation Network (JAN) and his company's insurance company are included. PMID:24441209

  16. Hands-On Nuclear Physics

    ERIC Educational Resources Information Center

    Whittaker, Jeff

    2013-01-01

    Nuclear science is an important topic in terms of its application to power generation, medical diagnostics and treatment, and national defense. Unfortunately, the subatomic domain is far removed from daily experience, and few learning aids are available to teachers. What follows describes a low-tech, hands-on method to teach important concepts in…

  17. Prosthetic Hand Lifts Heavy Loads

    NASA Technical Reports Server (NTRS)

    Carden, James R.; Norton, William; Belcher, Jewell G.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand designed to enable amputee to lift diverse heavy objects like rocks and logs. Has simple serrated end effector with no moving parts. Prosthesis held on forearm by system of flexible straps. Features include ruggedness, simplicity, and relatively low cost.

  18. Hand held explosives detection system

    DOEpatents

    Conrad, Frank J.

    1992-01-01

    The present invention is directed to a sensitive hand-held explosives detection device capable of detecting the presence of extremely low quantities of high explosives molecules, and which is applicable to sampling vapors from personnel, baggage, cargo, etc., as part of an explosives detection system.

  19. Firecracker injuries to the hand.

    PubMed

    MacKenzie, D N; Green, J A; Viglione, W

    2001-03-01

    Between September 1999 and April 2000, the Hand Unit at St George Hospital, Sydney, treated three young men with severe injuries caused by holding a lighted firecracker. These cases illustrate the typical injuries seen with this mechanism of injury. They highlight the dangers of these explosive devices and the potential to improve the laws relating to fireworks. PMID:11280694

  20. Venous lakes of the hands

    SciTech Connect

    Levy, J.M.; Hessel, S.J.; Joseph, R.B.; Bodell, L.S.

    1985-09-01

    Following pharmacologic vasodilation, multiple vascular lakes were observed on angiograms of the hand in 55 patients. Most had no history of vascular anomalies or disease. The authors believe that these lakes are venous structures and that their filling is a physiologic phenomenon.

  1. Hand-held medical robots.

    PubMed

    Payne, Christopher J; Yang, Guang-Zhong

    2014-08-01

    Medical robots have evolved from autonomous systems to tele-operated platforms and mechanically-grounded, cooperatively-controlled robots. Whilst these approaches have seen both commercial and clinical success, uptake of these robots remains moderate because of their high cost, large physical footprint and long setup times. More recently, researchers have moved toward developing hand-held robots that are completely ungrounded and manipulated by surgeons in free space, in a similar manner to how conventional instruments are handled. These devices provide specific functions that assist the surgeon in accomplishing tasks that are otherwise challenging with manual manipulation. Hand-held robots have the advantages of being compact and easily integrated into the normal surgical workflow since there is typically little or no setup time. Hand-held devices can also have a significantly reduced cost to healthcare providers as they do not necessitate the complex, multi degree-of-freedom linkages that grounded robots require. However, the development of such devices is faced with many technical challenges, including miniaturization, cost and sterility, control stability, inertial and gravity compensation and robust instrument tracking. This review presents the emerging technical trends in hand-held medical robots and future development opportunities for promoting their wider clinical uptake. PMID:24927713

  2. An innovative and multi-functional smart vibration platform

    NASA Astrophysics Data System (ADS)

    Olmi, C.; Song, G.; Mo, Y. L.

    2007-08-01

    Recently, there has been increasing efforts to incorporate vibration damping or energy dissipation mechanisms into civil structures, particularly by using smart materials technologies. Although papers about structural vibration control using smart materials have been published for more than two decades, there has been little research in developing teaching equipment to introduce smart materials to students via in-classroom demonstration or hands-on experiments. In this paper, an innovative and multi-functional smart vibration platform (SVP) has been developed by the Smart Materials and Structures Laboratory at the University of Houston to demonstrate vibration control techniques using multiple smart materials for educational and research purposes. The vibration is generated by a motor with a mass imbalance mounted on top of the frame. Shape memory alloys (SMA) and magneto-rheological (MR) fluid are used to increase the stiffness and damping ratio, respectively, while a piezoceramic sensor (lead zirconate titanate, or PZT) is used as a vibration sensing device. An electrical circuit has been designed to control the platform in computer-control or manual mode through the use of knobs. The former mode allows for an automated demonstration, while the latter requires the user to manually adjust the stiffness and damping ratio of the frame. In addition, the system accepts network connections and can be used in a remote experiment via the internet. This platform has great potential to become an effective tool for teaching vibration control and smart materials technologies to students in civil, mechanical and electrical engineering for both education and research purposes.

  3. Microwave power transmitting phased array antenna research project

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.

    1978-01-01

    An initial design study and the development results of an S band RF power transmitting phased array antenna experiment system are presented. The array was to be designed, constructed and instrumented to permit wireless power transmission technology evaluation measurements. The planned measurements were to provide data relative to the achievable performance in the state of the art of flexible surface, retrodirective arrays, as a step in technically evaluating the satellite power system concept for importing to earth, via microwave beams, the nearly continuous solar power available in geosynchronous orbit. Details of the microwave power transmitting phased array design, instrumentation approaches, system block diagrams, and measured component and breadboard characteristics achieved are presented.

  4. Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective

    PubMed Central

    Brotman, Rebecca M.

    2011-01-01

    Vaginal bacterial communities are thought to help prevent sexually transmitted infections. Bacterial vaginosis (BV) is a common clinical syndrome in which the protective lactic acid–producing bacteria (mainly species of the Lactobacillus genus) are supplanted by a diverse array of anaerobic bacteria. Epidemiologically, BV has been shown to be an independent risk factor for adverse outcomes including preterm birth, development of pelvic inflammatory disease, and acquisition of sexually transmitted infections. Longitudinal studies of the vaginal microbiome using molecular techniques such as 16S ribosomal DNA analysis may lead to interventions that shift the vaginal microbiota toward more protective states. PMID:22133886

  5. Validation of Force Limited Vibration Testing at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Rice, Chad; Buehrle, Ralph D.

    2003-01-01

    Vibration tests were performed to develop and validate the forced limited vibration testing capability at the NASA Langley Research Center. The force limited vibration test technique has been utilized at the Jet Propulsion Laboratory and other NASA centers to provide more realistic vibration test environments for aerospace flight hardware. In standard random vibration tests, the payload is mounted to a rigid fixture and the interface acceleration is controlled to a specified level based on a conservative estimate of the expected flight environment. In force limited vibration tests, both the acceleration and force are controlled at the mounting interface to compensate for differences between the flexible flight mounting and rigid test fixture. This minimizes the over test at the payload natural frequencies and results in more realistic forces being transmitted at the mounting interface. Force and acceleration response data was provided by NASA Goddard Space Flight Center for a test article that was flown in 1998 on a Black Brant sounding rocket. The measured flight interface acceleration data was used as the reference acceleration spectrum. Using this acceleration spectrum, three analytical methods were used to estimate the force limits. Standard random and force limited vibration tests were performed and the results are compared with the flight data.

  6. Development of a force specification for a force-limited random vibration test

    SciTech Connect

    Stevens, R.R.

    1996-02-01

    Vibration testing, techniques have been developed and employed that reduce the overtesting caused by the essentially infinite mechanical impedance of the shaker in conventional vibration tests. With these ``force-limiting`` techniques, two vibration test specifications are used: the conventional acceleration specification, and an interface force specification. The vibration level of the shake table is controlled such that neither the table acceleration nor the force transmitted to the test item exceeds its specification, hence the name ``dual control`` vibration test. The effect of limiting the shake table vibration to the force specification is to reduce (``notch``) the shaker acceleration near some of the test item`s resonance frequencies. Several methods of deriving the force specification have been described in the literature. A new method is proposed in this paper that is based on a modal method of coupling two dynamic systems, in this case the ``source`` or launch vehicle, and the ``load`` or payload. The only information that is required is an experimentally-measurable frequency-response function (FRF) called the dynamic mass for both the source and the load. The method, referred to as the coupled system, modal approach (CSMA) method, is summarized and compared to an existing method of determining the force specification for force-limited vibration testing.

  7. Noninterference Systems Developed for Measuring and Monitoring Rotor Blade Vibrations

    NASA Technical Reports Server (NTRS)

    Kurkov, Anatole P.

    2003-01-01

    In the noninterference measurement of blade vibrations, a laser light beam is transmitted to the rotor blade tips through a single optical fiber, and the reflected light from the blade tips is collected by a receiving fiber-optic bundle and conducted to a photodetector. Transmitting and receiving fibers are integrated in an optical probe that is enclosed in a metal tube which also houses a miniature lens that focuses light on the blade tips. Vibratory blade amplitudes can be deduced from the measurement of the instantaneous time of arrival of the blades and the knowledge of the rotor speed. The in-house noninterference blade-vibration measurement system was developed in response to requirements to monitor blade vibrations in several tests where conventional strain gauges could not be installed or where there was a need to back up strain gauges should critical gauges fail during the test. These types of measurements are also performed in the aircraft engine industry using proprietary in-house technology. Two methods of measurement were developed for vibrations that are synchronous with a rotor shaft. One method requires only one sensor; however, it is necessary to continuously record the data while the rotor is being swept through the resonance. In the other method, typically four sensors are employed and the vibratory amplitude is deduced from the data by performing a least square fit to a harmonic function. This method does not require continuous recording of data through the resonance and, therefore, is better suited for monitoring. The single-probe method was tested in the Carl facility at the Wright- Patterson Air Force Base, and the multiple-probe method was tested in NASA Glenn Research Center's Spin Rig facility, which uses permanent magnets to excite synchronous vibrations. Representative results from this test are illustrated in the bar chart. Nonsynchronous vibrations were measured online during testing of the Quiet High Speed Fan in Glenn s 9- by 15-Foot

  8. Tremulatory and Abdomen Vibration Signals Enable Communication through Air in the Stink Bug Euschistus heros

    PubMed Central

    Kavčič, Andreja; Čokl, Andrej; Laumann, Raúl A.; Blassioli-Moraes, Maria Carolina; Borges, Miguel

    2013-01-01

    Communication by substrate-borne mechanical signals is widespread among animals but remains one of their least understood communication channels. Past studies of vibrational communication in insects have been oriented predominantly to communication during mating, showing that species- and sex-specific vibrational signals enable recognition and localization of potential mates on continuous solid substrates. No special attention has been paid to vibrational signals with less obvious specificity as well as to the possibility of vibrational communication across substrates that are not in physical contact. We aimed to reinvestigate emission of the aforementioned vibrational signals transmitted through a plant in the stink bug Euschistus heros (Pentatomidae: Pentatominae) and to check whether individuals are able to communicate across adjecent, physically separated substrates. We used laser vibrometry for registration of substrate-borne vibrational signals on a bean plant. Using two bean plants separated for 3 to 7 cm between two most adjacent leaves, we investigated the possibility of transmission of these signals through air. Our study showed that males and females of E. heros communicate using tremulatory, percussion and buzzing signals in addition to the previously described signals produced by vibrations of the abdomen. Contrary to the latter, the first three signal types did not differ between sexes or between pentatomid species. Experiments with two physically separated plants showed significant searching behaviour and localization of vibrational signals of an E. heros male or a female, in response to abdominal vibration produced signals of a pair duetting on the neighbouring plant, in comparison to control where no animals were on the neighbouring plant. We also confirmed that transmission through air causes amplitude and frequency decay of vibrational signals, which suggests high-amplitude, low-frequency tremulatory signals of these stink bugs their most

  9. Exploiting synthetic aperture radar imagery for retrieving vibration signatures of concealed machinery

    NASA Astrophysics Data System (ADS)

    Pérez, Francisco; Campbell, Justin B.; Jaramillo, Monica; Dunkel, Ralf; Atwood, Thomas; Doerry, Armin; Gerstle, Walter H.; Santhanam, Balu; Hayat, Majeed M.

    2016-05-01

    It has been demonstrated that the instantaneous acceleration associated with vibrating objects that are directly imaged by synthetic aperture radar (SAR) can be estimated through the application of the discrete fractional Fourier transform (DFrFT) using the information contained in the complex SAR image. In general, vibration signatures may include, for example, the number of chirped sinusoids as well as their respective base frequencies and chirp rates. By further processing the DFrFT-processed data for clutter-noise rejection by means of pseudo- subspace methods, has been shown that the SAR-vibrometry method can be reliable as long as the signal-to-noise ratio (SNR) and the signal-to-clutter ratio (SCR) of the slow-time SAR signal at the range-line of interest exceeds 15dB. Meanwhile, the Nyquist theorem dictates that the maximum measurable vibration frequency is limited by half of the pulse-repetition frequency. This paper focuses on the detection and estimation of vibrations generated by machinery concealed within buildings and other structures. This is a challenging task in general because the vibration signatures of the source are typically altered by their housing structure; moreover, the SNR at the surface of the housing structure tends to be reduced. Here, experimental results for three different vibrating targets, including one concealed target, are reported using complex SAR images acquired by the General Atomics Lynx radar at resolutions of 1-ft and 4-in. The concealed vibrating target is actuated by a gear motor with an off-balance weight attached to it, which is enclosed by a wooden housing. The vibrations of the motor are transmitted to a chimney that extends above the housing structure. Using the SAR vibrometry approach, it is shown that it is possible to distinguish among the three vibrating objects based upon their vibration signatures.

  10. The bio-response of osteocytes and its regulation on osteoblasts under vibration.

    PubMed

    Wu, Xin-Tong; Sun, Lian-Wen; Qi, Hong-Yu; Shi, Hao; Fan, Yu-Bo

    2016-04-01

    Vibration, especially at low magnitude and high frequency (LMHF), was demonstrated to be anabolic for bone, but how the LMHF vibration signal is perceived by osteocytes is not fully studied. On the other hand, the mechanotransduction of osteocytes under shear stress has been scientists' primary focus for years. Due to the small strain caused by low-magnitude vibration, whether the previous explanation for shear stress will still work for LMHF vibration is unknown. In this study, a finite element method (FEM) model based on the real geometrical shape of an osteocyte was built to compare the mechanical behaviors of osteocytes under LMHF vibration and shear stress. The bio-response of osteocytes to vibration under different frequencies, including the secretion of soluble factors and the concentration of intracellular calcium, were studied. The regulating effect of the conditioned medium (CM) from vibrated osteocytes on osteoblasts was also studied. The FEM analysis result showed the cell membrane deformation under LMHF vibration was very small (with a peak value of 1.09%) as compared to the deformation caused by shear stress (with a peak value of 6.65%). The F-actin stress fibers of osteocytes were reorganized, especially on the nucleus periphery after LMHF vibration. The vibration at 30 Hz has a promoting effect on osteocytes and the osteogenesis of osteoblasts, whereas vibration at 90 Hz was suppressive. These results lead to a conclusion that the bio-response of osteocytes to LMHF vibration is frequency-dependent and is more related to the cytoskeleton on nuclear periphery rather than the membrane deformation. PMID:26715381

  11. Melt Stirring by Horizontal Crucible Vibration

    NASA Technical Reports Server (NTRS)

    Wolf, M. F.; Elwell, D.; Feigelson, R. S.

    1985-01-01

    Horizontal vibration suggested as technique for more effective stirring of melts in crystal-growth apparatus. Vibrational technique may replace accelerated crucible rotation. Potential superiority of vibrational technique shown by preliminary experiments in which ink stirred into water.

  12. 14 CFR 27.907 - Engine vibration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... engine to excessive vibration stresses. This must be shown by a vibration investigation. (c) No part of the rotor drive system may be subjected to excessive vibration stresses. Rotor Drive System...

  13. 14 CFR 27.907 - Engine vibration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... engine to excessive vibration stresses. This must be shown by a vibration investigation. (c) No part of the rotor drive system may be subjected to excessive vibration stresses. Rotor Drive System...

  14. Studies Of Vibrations In Gearboxes

    NASA Technical Reports Server (NTRS)

    Choy, Fred K.; Ruan, Yeefeng F.; Tu, Yu K.; Zakrajsek, James J.; Oswald, Fred B.; Coy, John J.; Townsend, Dennis P.

    1994-01-01

    Three NASA technical memorandums summarize studies of vibrations in gearboxes. Directed toward understanding and reducing gearbox noise caused by coupling of vibrations from meshing gears, through gear shafts and their bearings, to surfaces of gearbox housings. Practical systems in which understanding and reduction of gearbox noise beneficial include helicopter, car, and truck transmissions; stationary geared systems; and gear-driven actuator systems.

  15. Vibration Response of Airplane Structures

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore; Gelalles, A G

    1935-01-01

    This report presents test results of experiments on the vibration-response characteristics of airplane structures on the ground and in flight. It also gives details regarding the construction and operation of vibration instruments developed by the National Advisory Committee for Aeronautics.

  16. Drillstring vibrations create crooked holes

    SciTech Connect

    Dareing, D.W.

    1984-01-01

    Boreholes in hard formations sometimes deviate when the drillstring runs rough or the kelly bounces severely. This article explains how drillstring vibrations produce crooked holes in hard formations. It shows how to reduce dog-leg severity through vibration control. Dog-legs are known to produce cyclic bending-type fatigue loads in drill pipe and collars. Longitudinal and torsional vibrational stresses are additive to rotational bending and further reduce the life of drillstring tubulars. Vibration-induced dog-legs are therefore more damaging to drillstrings than other dog-leg producing mechanisms because total cyclic fatigue loading is the combined effect of bending stress reversal due to rotation plus vibrational stress variations. The vibration-induced dog-leg concept is based on overall vibration response of drillstrings, resultant dynamic displacements of roller cone drill bits, and corresponding dynamic forces between bit and formation. The concept explains how dynamic forces generated by roller cone rock bits might produce helical bore holes in hard homogeneous formations. Dog-legs in hard formations may be due in part to drillstring vibrations. The wellbore deviation concept relates only to roller cone rock bits and is based on dynamically reorienting three-lobed formation pattern hammered out by bottomhole assembly resonance. Analytical studies are needed to determine the effect of bit force impact point location on chip formation and rock removal. Field studies of various bottom hole assemblies operating at critical rotary speeds coupled with directional surveys are needed to test the validity of this theory.

  17. Longitudinally-vibrating surgical microelectrode

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Crawford, D.; Kawabus, E. W.

    1977-01-01

    Microelectrode attached to cone of loudspeaker imparting longitudinal vibrations, penetrates relatively tough tissue of arterial walls easier and with more precise depth control because dimpling is eliminated. Vibrating microelectrode has been successfully used to make accurate oxygen-content measurements in arterial walls.

  18. Die Sprache der Hande zu den Handen sprechen (Talking the Language of the Hands to the Hands). DB-LINK.

    ERIC Educational Resources Information Center

    Miles, Barbara

    This paper examines the importance of hands for the person who is deafblind, reviews hand development, and identifies specific teaching skills that facilitate hand development and expressiveness in persons who are deafblind. It notes that the hands of a deafblind individual serve not only as tools but also as sense organs (to compensate for their…

  19. Kathleen England watches her image transmitted to shuttle

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Kathleen England watches her image transmitted to her husband in the shuttle via the Shuttle Amateur Radio Experiment (SAREX). Looking on are amateur radio operators employed at JSC: Gil Carman (WA5NOM); Lou McFaddin (WSDIO), and Candy Torres (KASUKJ).

  20. Kathleen England watches her image transmitted to shuttle

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Kathleen England (foreground and on monitor) watches her image transmitted to her husband in the shuttle via the Shuttle Amateur Radio Experiment (SAREX). Looking on are amateur radio operators employed at JSC: Gil Carman (WA5NOM); Lou McFaddin (WSDIO), and Candy Torres (KASUKJ).