A Wearable Hydration Sensor with Conformal Nanowire Electrodes.

PubMed

Yao, Shanshan; Myers, Amanda; Malhotra, Abhishek; Lin, Feiyan; Bozkurt, Alper; Muth, John F; Zhu, Yong

2017-03-01

A wearable skin hydration sensor in the form of a capacitor is demonstrated based on skin impedance measurement. The capacitor consists of two interdigitated or parallel electrodes that are made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. The flexible and stretchable nature of the AgNW/PDMS electrode allows conformal contact to the skin. The hydration sensor is insensitive to the external humidity change and is calibrated against a commercial skin hydration system on an artificial skin over a wide hydration range. The hydration sensor is packaged into a flexible wristband, together with a network analyzer chip, a button cell battery, and an ultralow power microprocessor with Bluetooth. In addition, a chest patch consisting of a strain sensor, three electrocardiography electrodes, and a skin hydration sensor is developed for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless, and continuous monitoring of skin hydration and other health parameters. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D ultrasound image guidance system used in RF uterine adenoma and uterine bleeding ablation system

NASA Astrophysics Data System (ADS)

Ding, Mingyue; Luo, Xiaoan; Cai, Chao; Zhou, Chengping; Fenster, Aaron

2006-03-01

Uterine adenoma and uterine bleeding are the two most prevalent diseases in Chinese women. Many women lose their fertility from these diseases. Currently, a minimally invasive ablation system using an RF button electrode is being used in Chinese hospitals to destroy tumor cells or stop bleeding. In this paper, we report on a 3D US guidance system developed to avoid accidents or death of the patient by inaccurate localization of the tumor position during treatment. A 3D US imaging system using a rotational scanning approach of an abdominal probe was built. In order to reduce the distortion produced when the rotational axis is not collinear with the central beam of the probe, a new 3D reconstruction algorithm is used. Then, a fast 3D needle segmentation algorithm is used to find the electrode. Finally, the tip of electrode is determined along the segmented 3D needle and the whole electrode is displayed. Experiments with a water phantom demonstrated the feasibility of our approach.

Acoustic transducer with damping means

DOEpatents

Smith, Richard W.; Adamson, Gerald E.

1976-11-02

An ultrasonic transducer specifically suited to high temperature sodium applications is described. A piezoelectric active element is joined to the transducer faceplate by coating the faceplate and juxtaposed active element face with wetting agents specifically compatible with the bonding procedure employed to achieve the joint. The opposite face of the active element is fitted with a backing member designed to assure continued electrical continuity during adverse operating conditions which can result in the fracturing of the active element. The fit is achieved employing a spring-loaded electrode operably arranged to electrically couple the internal transducer components, enclosed in a hermetically sealed housing, to accessory components normally employed in transducer applications. Two alternative backing members are taught for assuring electrical continuity. The first employs a resilient, discrete multipoint contact electrode in electrical communication with the active element face. The second employs a resilient, elastomeric, electrically conductive, damped member in electrical communication with the active element face in a manner to effect ring-down of the transducer. Each embodiment provides continued electrical continuity within the transducer in the event the active element fractures, while the second provides the added benefit of damping.

500 MHz narrowband beam position monitor electronics for electron synchrotrons

NASA Astrophysics Data System (ADS)

Mohos, I.; Dietrich, J.

1998-12-01

Narrowband beam position monitor electronics were developed in the Forschungszentrum Jülich-IKP for the orbit measurement equipment used at ELSA Bonn. The equipment uses 32 monitor chambers, each with four capacitive button electrodes. The monitor electronics, consisting of an rf signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ), sequentially process and measure the monitor signals and deliver calculated horizontal and vertical beam position data via a serial network.

Note: Novel trigger pulse feed method for mega-volt gas switch.

PubMed

Yin, Jiahui; Sun, Fengju; Jiang, Xiaofeng; Wang, Zhiguo; Liang, Tianxue; Jiang, Hongyu; Qiu, Aici

2017-07-01

It is difficult to feed the trigger pulse into an electrically triggered mega-volt switch, and the present note presents a novel trigger pulse feed method. The trigger pulse is introduced via a damping resistor, which is mounted between the inner and outer cylindrical electrodes of the pulse transmission line. The mega-volt pulse is damped because the voltage is resistively divided by the resistor and trigger cable arrangement. Both the complex breakdown processes of the switch and its insulation issues are experimentally studied. The function and the beneficial effects of the damping resistor, installed together with an additional inductor, are discussed. Finally, the parameters of these two damping components are set to 500 Ω and 2 μH values for which the switch has been demonstrated to work successfully at over 2.3 MV.

Kinetic damping in the spectra of the spherical impedance probe

NASA Astrophysics Data System (ADS)

Oberrath, J.

2018-04-01

The impedance probe is a measurement device to measure plasma parameters, such as electron density. It consists of one electrode connected to a network analyzer via a coaxial cable and is immersed into a plasma. A bias potential superposed with an alternating potential is applied to the electrode and the response of the plasma is measured. Its dynamical interaction with the plasma in an electrostatic, kinetic description can be modeled in an abstract notation based on functional analytic methods. These methods provide the opportunity to derive a general solution, which is given as the response function of the probe–plasma system. It is defined by the matrix elements of the resolvent of an appropriate dynamical operator. Based on the general solution, a residual damping for vanishing pressure can be predicted and can only be explained by kinetic effects. In this paper, an explicit response function of the spherical impedance probe is derived. Therefore, the resolvent is determined by its algebraic representation based on an expansion in orthogonal basis functions. This allows one to compute an approximated response function and its corresponding spectra. These spectra show additional damping due to kinetic effects and are in good agreement with former kinetically determined spectra.

An approach to determination of shunt circuits parameters for damping vibrations

NASA Astrophysics Data System (ADS)

Matveenko; Iurlova; Oshmarin; Sevodina; Iurlov

2018-04-01

This paper considers the problem of natural vibrations of a deformable structure containing elements made of piezomaterials. The piezoelectric elements are connected through electrodes to an external electric circuit, which consists of resistive, inductive and capacitive elements. Based on the solution of this problem, the parameters of external electric circuits are searched for to allow optimal passive control of the structural vibrations. The solution to the problem is complex natural vibration frequencies, the real part of which corresponds to the circular eigenfrequency of vibrations and the imaginary part corresponds to its damping rate (damping ratio). The analysis of behaviour of the imaginary parts of complex eigenfrequencies in the space of external circuit parameters allows one to damp given modes of structure vibrations. The effectiveness of the proposed approach is demonstrated using a cantilever-clamped plate and a shell structure in the form of a semi-cylinder connected to series resonant ? circuits.

Anharmonic 1D actuator model including electrostatic and Casimir forces with fractional damping perturbed by an external force

NASA Astrophysics Data System (ADS)

Mansoori Kermani, Maryam; Dehestani, Maryam

2018-06-01

We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell-Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant.

Anharmonic 1D actuator model including electrostatic and Casimir forces with fractional damping perturbed by an external force

NASA Astrophysics Data System (ADS)

Mansoori Kermani, Maryam; Dehestani, Maryam

2018-03-01

We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell-Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant.

Simplification of the helical TEN2 laser

NASA Astrophysics Data System (ADS)

Krahn, K.-H.

1980-04-01

The observation that the helical TEN2 laser can effectively be simplified by giving up the use of decoupling elements as well as by abolishing the segmentation of the electrode structure is examined. Although, as a consequence of this simplification, the operating pressure range was slightly decreased, the output power could be improved by roughly 30%, a result which is attributed to the new electrode geometry exhibiting lower inductance and lower damping losses.

Damping of Plasma Waves in Multi-species Ion Plasmas

NASA Astrophysics Data System (ADS)

Anderegg, Francois; Affolter, Matthew; Driscoll, C. Fred

2015-11-01

The damping of Langmuir waves in multi-species pure ion plasmas is measured over four decades in temperature covering regimes of Landau, bounce harmonics, and interspecies drag damping. Thermal cyclotron spectroscopy determines the plasma composition. The plasma is predominantly Mg+ resulting from a Mg electrode arc, with roughly 5-30% other ions, typically H3O+ and O2+,arising from ionization and chemical reactions with the residual background gas. The plasma temperature is controlled with laser cooling of the Mg24 ions over the range 10-4 <= T <= 1 eV. For T >= 0 .1 eV, the damping rates agree closely with Landau theory for θ-symmetric standing waves, with discrete wavenumber k1 = π /Lp . At lower temperature 10-2 <= T <= 0 . 1 eV the damping is not fully understood, but is most likely a result of Landau damping on higher kz bounce harmonics produced by the rounded plasma ends. For T <=10-2 eV, damping rates 10 <= γ <=103 s-1 are proportional to the ion-ion collisionality νii ~T - 3 / 2 , consistent with a theory prediction that includes interspecies drag. A decrease in γ is observed at T <=10-3 eV, presumably due to strong magnetization, centrifugal separation of the species, and the collisionality approaching the mode frequencyf1 ~20 kHz. Supported by DOE grant DE-SC0002451.

Histopathologic changes after bipolar resection of the prostate: depth of penetration of bipolar thermal injury.

PubMed

Maddox, Michael; Pareek, Gyan; Al Ekish, Shadi; Thavaseelan, Simone; Mehta, Akanksha; Mangray, Shamlal; Haleblian, George

2012-10-01

While the power needed to initiate bipolar vaporization is higher than conventional monopolar resection, the energy needed to maintain bipolar vaporization is significantly lower and may result in less thermal tissue injury. This may have implications for hemostasis, scarring, and perioperative morbidity. The objective of this study is to assess histopathologic changes in prostatic tissue after bipolar transurethral vaporization of the prostate. Male patients older than 40 years with a diagnosis of benign prostatic hyperplasia (BPH) who elected to undergo bipolar transurethral vaporization of the prostate were included in this study. Patients were excluded if they had a previous transurethral resection of the prostate (TURP) or prostate radiation therapy. An Olympus button vaporization electrode was used to vaporize prostate tissue. A loop electrode was then used to obtain a deep resection specimen. The vaporized and loop resection surfaces were inked and sent for pathologic analysis to determine the presence of gross histologic changes and the depth of penetration of the bipolar vaporization current. A total of 12 men underwent bipolar TURP at standard settings of 290 W cutting and 145 W coagulation current. Mean patient age was 70±10.2 years (range 56-88 years). Mean surgical time was 48.7±20.2 minutes (range 30-89 min). Mean depth of thermal injury was 2.4±0.84 mm (range 0.3-3.5 mm). Histopathologic evaluation demonstrated thermal injury in all specimens, but no gross char was encountered. In bipolar systems, resection takes place at much lower peak voltages and temperatures compared with monopolar systems. Theoretically, this leads to less collateral thermal damage and tissue char. Our tissue study illustrates that the button vaporization electrode achieves a much larger depth of penetration than previous studies of bipolar TURP. This may be because thermal injury represents a gradual continuum of histologic changes.

Improved Tensile Adhesion Specimens for High Strength Epoxy Systems in Aerospace Applications

NASA Technical Reports Server (NTRS)

Haddock, M. Reed; McLennan, Michael L.

2000-01-01

An improved tensile adhesion button has been designed and tested that results in higher measured tensile adhesion strength while providing increased capability for testing high strength epoxy adhesive systems. The best attributes of two well-established tensile button designs were combined and refined into an optimized tensile button. The most significant design change to the tensile button was to improve alignment of the bonded tensile button specimens during tensile testing by changing the interface between the tensile button and the tensile test machine. The established or old button design uses a test fixture that pulls from a grooved annulus or anvil head while the new button design pulls from a threaded hole in the centerline of the button. Finite element (FE) analysis showed that asymmetric loading of the established anvil head tensile button significantly increases the stress concentration in the adhesive, causing failure at lower tensile test loads. The new tensile button was designed to eliminate asymmetric loading and eliminate misalignment sensitivity. Enhanced alignment resulted in improved tensile adhesion strength measurement up to 13.8 MPa (2000psi) over the established button design. Another design change increased the capability of the button by increasing the threaded hole diameter allowing it to test high strength epoxy systems up to 85 MPa(less than 12,000 psi). The improved tensile button can be used in button- to-button or button-to-panel configurations.

Deformation of Cases in High Capacitance Value Wet Tantalum Capacitors under Environmental Stresses

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2016-01-01

Internal gas pressure in hermetic wet tantalum capacitors is created by air, electrolyte vapor, and gas generated by electrochemical reactions at the electrodes. This pressure increases substantially with temperature and time of operation due to excessive leakage currents. Deformation of the case occurs when the internal pressure exceeds pressure of the environments and can raise significantly when a part operates in space. Contrary to the cylinder case wet tantalum capacitors that have external sealing by welding and internal sealing provided by the Teflon bushing and crimping of the case, no reliable internal sealing exists in the button case capacitors. Single seal design capacitors are used for high capacitance value wet tantalum capacitors manufactured per DLA L&M drawings #04003, 04005, and 10011, and require additional analysis to assure their reliable application in space systems. In this work, leakage currents and case deformation of button case capacitors were measured during different environmental test conditions. Recommendations for derating, screening and qualification testing are given. This work is a continuation of a series of NEPP reports related to quality and reliability of wet tantalum capacitors.

Multichannel electrochemical microbial detection unit

NASA Technical Reports Server (NTRS)

Wilkins, J. R.; Young, R. N.; Boykin, E. H.

1978-01-01

The paper describes the design and capabilities of a compact multichannel electrochemical unit devised to detect and automatically indicate detection time length of bacteria. By connecting this unit to a strip-chart recorder, a permanent record is obtained of the end points and growth curves for each of eight channels. The experimental setup utilizing the multichannel unit consists of a test tube (25 by 150 mm) containing a combination redox electrode plus 18 ml of lauryl tryptose broth and positioned in a 35-C water bath. Leads from the electrodes are connected to the multichannel unit, which in turn is connected to a strip-chart recorder. After addition of 2.0 ml of inoculum to the test tubes, depression of the push-button starter activates the electronics, timer, and indicator light for each channel. The multichannel unit is employed to test tenfold dilutions of various members of the Enterobacteriaceae group, and a typical dose-response curve is presented.

Successive approximation algorithm for beam-position-monitor-based LHC collimator alignment

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Nosych, Andriy A.; Bruce, Roderik; Gasior, Marek; Mirarchi, Daniele; Redaelli, Stefano; Salvachua, Belen; Wollmann, Daniel

2014-02-01

Collimators with embedded beam position monitor (BPM) button electrodes will be installed in the Large Hadron Collider (LHC) during the current long shutdown period. For the subsequent operation, BPMs will allow the collimator jaws to be kept centered around the beam orbit. In this manner, a better beam cleaning efficiency and machine protection can be provided at unprecedented higher beam energies and intensities. A collimator alignment algorithm is proposed to center the jaws automatically around the beam. The algorithm is based on successive approximation and takes into account a correction of the nonlinear BPM sensitivity to beam displacement and an asymmetry of the electronic channels processing the BPM electrode signals. A software implementation was tested with a prototype collimator in the Super Proton Synchrotron. This paper presents results of the tests along with some considerations for eventual operation in the LHC.

Acoustic-wave-damping experimental study in x-ray preionized high-repetition rate XeCl

NASA Astrophysics Data System (ADS)

Canarelli, Patrick; Sentis, Marc L.; Delaporte, Philippe C.; Fontaine, Bernard L.; Forestier, Bernard M.

1990-08-01

To increase the pulse repetition frequency, the average power, and the beam quality of excimer laser systems, damping of the strong acoustic waves induced by the active medium excitation must be solve. In order to achieve this goal different electrodes and acoustic damping configuration have been studied. Excitation of active medium (energy deposition : 50 to 150 J/l) at high repetition rate (up to 1 000 Hz) in a subsonic loop (flow velocity : up to 65 m/s) is achieved by means of a classical discharge, through transfers capacitors. The discharge is preionized by X-Ray generated by a wire ion plasma gun. Previous studies done at I.M.F.M. have shown that the density perturbations, induced by successive excitations at high repetition rate (up to 1000 Hz), can involve output energy decrease. Here, we will present and discuss the density or pressure perturbation maximum level which don't involve this laser energy decrease; acoustic and thermal effects have been notably took account. We will study the possibilities of fast pressure perturbations damping.

Intrusions of a drowsy mind: neural markers of phenomenological unpredictability.

PubMed

Noreika, Valdas; Canales-Johnson, Andrés; Koh, Justin; Taylor, Mae; Massey, Irving; Bekinschtein, Tristan A

2015-01-01

The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e., the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 s before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals.

An all-silicon single-wafer micro-g accelerometer with a combined surface and bulk micromachining process

NASA Technical Reports Server (NTRS)

Yazdi, N.; Najafi, K.

2000-01-01

This paper reports an all-silicon fully symmetrical z-axis micro-g accelerometer that is fabricated on a single-silicon wafer using a combined surface and bulk fabrication process. The microaccelerometer has high device sensitivity, low noise, and low/controllable damping that are the key factors for attaining micro g and sub-micro g resolution in capacitive accelerometers. The microfabrication process produces a large proof mass by using the whole wafer thickness and a large sense capacitance by utilizing a thin sacrificial layer. The sense/feedback electrodes are formed by a deposited 2-3 microns polysilicon film with embedded 25-35 microns-thick vertical stiffeners. These electrodes, while thin, are made very stiff by the thick embedded stiffeners so that force rebalancing of the proof mass becomes possible. The polysilicon electrodes are patterned to create damping holes. The microaccelerometers are batch-fabricated, packaged, and tested successfully. A device with a 2-mm x 1-mm proof mass and a full bridge support has a measured sensitivity of 2 pF/g. The measured sensitivity of a 4-mm x 1-mm accelerometer with a cantilever support is 19.4 pF/g. The calculated noise floor of these devices at atmosphere are 0.23 micro g/sqrt(Hz) and 0.16 micro g/sqrt(Hz), respectively.

Cochlear microphonic responses to acoustic clicks in guinea pig and their relation with microphonic responses to pure tones.

PubMed

Echeverría, E L; Robles, L W

1983-02-01

Cochlear microphonic (CM) responses to acoustic transient stimuli were studied at the three more basal turns of the cochlea in the guinea pig. The responses to rarefaction and condensation pressure pulses of less than 100-mus duration were recorded using the differential electrode technique. In some animals the CM response to pure tones was recorded at the same position at which the transient response was obtained. The transient responses recorded at the three turns of the cochlea displayed a damped oscillation at a frequency consistent with the values of cutoff frequency already known for the electrode positions. Some of the responses were significantly less damped than click responses previously reported. There was a good correlation between the cutoff frequency in the frequency response curve and the frequency of oscillation in the transient response for recordings obtained at the same position in the cochlea. A nonlinear effect was observed for changes in stimulus intensity. There was a less than proportional decrease in amplitude of the initial part of the damped oscillation for a decrease of the stimulus intensity, while the late part of the response behaved almost linearly. This nonlinearity observed in the CM transient response could not be explained by a nonlinear characteristic of the sort reported in the basilar membrane of the squirrel monkey by Robles et al. [J. Acoust. Soc. Am. 59, 926-939 (1976)]; rather it seems to be a saturation nonlinearity similar to the one known for sinusoidal stimulation.

Diagnosing Tic Disorders

MedlinePlus

... span class="tp-sr-only">Submit Button Submit Button New, Efficient, and Reliable Air Electrode Material for Proton-Conducting Reversible Solid Oxide Cells.

PubMed

Huan, Daoming; Shi, Nai; Zhang, Lu; Tan, Wenzhou; Xie, Yun; Wang, Wanhua; Xia, Changrong; Peng, Ranran; Lu, Yalin

2018-01-17

Driven by the demand to minimize fluctuation in common renewable energies, reversible solid oxide cells (RSOCs) have drawn increasing attention for they can operate either as fuel cells to produce electricity or as electrolysis cells to store electricity. Unfortunately, development of proton-conducting RSOCs (P-RSOCs) faces a major challenge of poor reliability because of the high content of steam involved in air electrode reactions, which could seriously decay the lifetime of air electrode materials. In this work, a very stable and efficient air electrode, SrEu 2 Fe 1.8 Co 0.2 O 7-δ (SEFC) with layer structure, is designed and deployed in P-RSOCs. X-ray diffraction analysis and High-angle annular dark-filed scanning transmission electron microscopy images of SEFC reveal that Sr atoms occupy the center of perovskite slabs, whereas Eu atoms arrange orderly in the rock-salt layer. Such a special structure of SEFC largely depresses its Lewis basicity and therefore its reactivity with steam. Applying the SEFC air electrode, our button switches smoothly between both fuel cell and electrolysis cell (EC) modes with no obvious degradation over a 135 h long-term test under wet H 2 (∼3% H 2 O) and 10% H 2 O-air atmospheres. A record of over 230 h is achieved in the long-term stability test in the EC mode, doubling the longest test that had been previously reported. Besides good stability, SEFC demonstrates great catalytic activity toward air electrode reactions when compared with traditional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ air electrodes. This research highlights the potential of stable and efficient P-RSOCs as an important part in a sustainable new energy power system.

Orange Button Solar Data Exchange | Energy Analysis | NREL

Science.gov Websites

Orange Button Solar Data Exchange Orange Button Solar Data Exchange The new Orange Button Solar Data Exchange tool serves as an online resource for the solar industry to share, sell, or retrieve solar data and connect with colleagues. Screenshot image of Orange Button data website home page. The

Tourette Syndrome (TS): Risk Factors and Causes

MedlinePlus

... span class="tp-sr-only">Submit Button Submit Button Intrusions of a drowsy mind: neural markers of phenomenological unpredictability

PubMed Central

Noreika, Valdas; Canales-Johnson, Andrés; Koh, Justin; Taylor, Mae; Massey, Irving; Bekinschtein, Tristan A.

2015-01-01

The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e., the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 s before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals. PMID:25814962

Smartphone home monitoring of ECG

NASA Astrophysics Data System (ADS)

Szu, Harold; Hsu, Charles; Moon, Gyu; Landa, Joseph; Nakajima, Hiroshi; Hata, Yutaka

2012-06-01

A system of ambulatory, halter, electrocardiography (ECG) monitoring system has already been commercially available for recording and transmitting heartbeats data by the Internet. However, it enjoys the confidence with a reservation and thus a limited market penetration, our system was targeting at aging global villagers having an increasingly biomedical wellness (BMW) homecare needs, not hospital related BMI (biomedical illness). It was designed within SWaP-C (Size, Weight, and Power, Cost) using 3 innovative modules: (i) Smart Electrode (lowpower mixed signal embedded with modern compressive sensing and nanotechnology to improve the electrodes' contact impedance); (ii) Learnable Database (in terms of adaptive wavelets transform QRST feature extraction, Sequential Query Relational database allowing home care monitoring retrievable Aided Target Recognition); (iii) Smartphone (touch screen interface, powerful computation capability, caretaker reporting with GPI, ID, and patient panic button for programmable emergence procedure). It can provide a supplementary home screening system for the post or the pre-diagnosis care at home with a build-in database searchable with the time, the place, and the degree of urgency happened, using in-situ screening.

Illuminated push-button switch

NASA Technical Reports Server (NTRS)

Iwagiri, T.

1983-01-01

An illuminated push-button switch is described. It is characterized by the fact that is consists of a switch group, an operator button opening and closing the switch group, and a light-emitting element which illuminates the face of the operator button.

76 FR 54741 - Proposed Additions and Deletions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-02

...-6823--Button, Silver Oxide, 1.55V. NSN: 6135-01-538-0997--Button, Lithium, 3V. NSN: 6135-01-452-8160--Button, Lithium, 3V. NSN: 6135-01-301-8776--Lithium, AA, 3.6V . NSN: 6135-01-246-0307--Button, Silver...

Blue Button use by patients to access and share health record information using the Department of Veterans Affairs' online patient portal.

PubMed

Turvey, Carolyn; Klein, Dawn; Fix, Gemmae; Hogan, Timothy P; Woods, Susan; Simon, Steven R; Charlton, Mary; Vaughan-Sarrazin, Mary; Zulman, Donna M; Dindo, Lilian; Wakefield, Bonnie; Graham, Gail; Nazi, Kim

2014-01-01

The Blue Button feature of online patient portals promotes patient engagement by allowing patients to easily download their personal health information. This study examines the adoption and use of the Blue Button feature in the Department of Veterans Affairs' (VA) personal health record portal, My HealtheVet. An online survey presented to a 4% random sample of My HealtheVet users between March and May 2012. Questions were designed to determine characteristics associated with Blue Button use, perceived value of use, and how Veterans with non-VA providers use the Blue Button to share information with their non-VA providers. Of the survey participants (N=18 398), 33% were current Blue Button users. The most highly endorsed benefit was that it helped patients understand their health history better because all the information was in one place (73%). Twenty-one percent of Blue Button users with a non-VA provider shared their VA health information, and 87% reported that the non-VA provider found the information somewhat or very helpful. Veterans' self-rated computer ability was the strongest factor contributing to both Blue Button use and to sharing information with non-VA providers. When comparing Blue Button users and non-users, barriers to adoption were low awareness of the feature and difficulty using the Blue Button. This study contributes to the understanding of early Blue Button adoption and use of this feature for patient-initiated sharing of health information. Educational efforts are needed to raise awareness of the Blue Button and to address usability issues that hinder adoption. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Fleet Environmental | USFF

Science.gov Websites

Leadership Expand Leadership About NEPA Projects Expand NEPA Projects At Sea Expand At Sea Ashore Expand Ashore Stewards of the Sea Expand Stewards of the Sea Media Resources Expand Media Resources Contact NEPA Projects Button Environmental At Sea Button Environmental Ashore Button Energy Button Stewards of

Active Damping Using Distributed Anisotropic Actuators

NASA Technical Reports Server (NTRS)

Schiller, Noah H.; Cabell, Randolph H.; Quinones, Juan D.; Wier, Nathan C.

2010-01-01

A helicopter structure experiences substantial high-frequency mechanical excitation from powertrain components such as gearboxes and drive shafts. The resulting structure-borne vibration excites the windows which then radiate sound into the passenger cabin. In many cases the radiated sound power can be reduced by adding damping. This can be accomplished using passive or active approaches. Passive treatments such as constrained layer damping tend to reduce window transparency. Therefore this paper focuses on an active approach utilizing compact decentralized control units distributed around the perimeter of the window. Each control unit consists of a triangularly shaped piezoelectric actuator, a miniature accelerometer, and analog electronics. Earlier work has shown that this type of system can increase damping up to approximately 1 kHz. However at higher frequencies the mismatch between the distributed actuator and the point sensor caused control spillover. This paper describes new anisotropic actuators that can be used to improve the bandwidth of the control system. The anisotropic actuators are composed of piezoelectric material sandwiched between interdigitated electrodes, which enables the application of the electric field in a preferred in-plane direction. When shaped correctly the anisotropic actuators outperform traditional isotropic actuators by reducing the mismatch between the distributed actuator and point sensor at high frequencies. Testing performed on a Plexiglas panel, representative of a helicopter window, shows that the control units can increase damping at low frequencies. However high frequency performance was still limited due to the flexible boundary conditions present on the test structure.

--No Title--

Science.gov Websites

{margin:0;padding:0;border:0;outline:0;line-height:1.3;text-decoration:none;font-size:100%;list-style:none -state-disabled{cursor:default!important}.ui-icon{display:block;text-indent:-99999px;overflow:hidden -align:middle;text-align:center;overflow:visible}.ui-button,.ui-button:link,.ui-button:visited,.ui-button:hover

Quantifying Non-Equilibrium in Hypersonic Flows Using Entropy Generation

DTIC Science & Technology

2007-03-01

mirror fabrication, 2) mirror actuation, and 3) control algorithms with a focus on potential for future space based applications. For a...electrodes transported via a conducting electrolyte [19]. When placed under a voltage potential , cations in a polymer matrix immediately swell...has the potential to create an over- damped surface preventing Wavescope from detecting any strains. The final step in the mirror fabrication is to

Button battery intake as foreign body in Chinese children: review of case reports and the literature.

PubMed

Liao, Wenjing; Wen, Guangyi; Zhang, Xiaowen

2015-06-01

Button batteries have been recognized as one of the dangerous foreign bodies to children for more than 30 years, but few related studies have been published to give more concern in China. We reported 6 cases of button battery intake as foreign body in children. The Chinese literature on button battery as foreign body in children was reviewed. The interval between the accidental ingestion and battery removal ranged from 6 hours to 3 days. Two patients had no sequela, 3 patients had tracheoesophageal fistulas, and 1 patient had nasal septal perforation. Twenty-eight articles about button battery as foreign body in children were obtained by Chinese-language literature searches including 25 case reports, 2 health education articles, and 1 imaging article. In total, 172 cases of button battery intake as foreign body in children were identified, 23 and 10 of the 159 cases involving nasal button battery lodgment developed nasal septal perforation and nasal adhesion, respectively. Tracheoesophageal fistula was identified in 4 of the 12 ingestion cases. One case of button battery intake was in external auditory canal. A small number of children with button battery as foreign body were reported in China, which is 1 of the biggest countries with large population of children.

Severity of button batteries ingestions: data from French Poison Control Centres between 1999 and 2015.

PubMed

Labadie, Magali; O'Mahony, Elisabeth; Capaldo, Lise; Courtois, Arnaud; Lamireau, Thierry; Nisse, Patrick; Blanc-Brisset, Ingrid; Puskarczyk, Emmanuel

2017-12-13

Although the ingestion of button batteries is an infrequent situation, it leads to a significant risk of causing serious damage. This study was carried out to describe all the cases of button battery ingestion recorded by the French Poison Control Centers over 16 years. All the cases of button battery ingestion were recorded from 1 January 1999 to the end of June 2015, analysed (age, sex, number of ingested button batteries, clinical signs and treatments) and graded for severity according to the poisoning severity score. The incidence of button batteries ingestions was constant over the 16-year period, with an average of 266±98.5 cases per year and a total of 4030 cases. Nevertheless, 21 cases were severe and two deaths occurred. Interestingly, for the two patients who died, the battery was stuck in the oesophagus and they presented anorexia and/or dysphagia, abdominal pain and fever and in one case, a melena 3 weeks after ingestion. Importantly, these symptoms were observed even if the battery was expelled in one fatal case. Ingestions of button batteries still occur and may cause serious damage, especially in children, and if the button battery is stuck in the oesophagus as it might cause severe symptoms. Patients who have ingested a button battery must be directed to the emergency department for medical evaluation, even if the button battery has been expelled from the body and even more if gastrointestinal symptoms are present.

A newly designed hydroxyapatite ceramic burr-hole button

PubMed Central

Kashimura, Hiroshi; Ogasawara, Kuniaki; Kubo, Yoshitaka; Yoshida, Kenji; Sugawara, Atsushi; Ogawa, Akira

2010-01-01

Conventional burr-hole buttons sometimes do not fit the burr hole well due to the curvature of the surrounding bone. An irregular surface at the border between the button and the surrounding skull may appear unaesthetic. The major problem is the difference between the curvature radius of the skull and the burr-hole button in contact with the skull. To solve this problem, the authors designed a button made of hydroxyapatite ceramic to snugly fit the burr hole. The specifications of this device and its clinical application are described here. PMID:20448795

A newly designed hydroxyapatite ceramic burr-hole button.

PubMed

Kashimura, Hiroshi; Ogasawara, Kuniaki; Kubo, Yoshitaka; Yoshida, Kenji; Sugawara, Atsushi; Ogawa, Akira

2010-03-24

Conventional burr-hole buttons sometimes do not fit the burr hole well due to the curvature of the surrounding bone. An irregular surface at the border between the button and the surrounding skull may appear unaesthetic. The major problem is the difference between the curvature radius of the skull and the burr-hole button in contact with the skull. To solve this problem, the authors designed a button made of hydroxyapatite ceramic to snugly fit the burr hole. The specifications of this device and its clinical application are described here.

Enhancement of the anti-damping spin torque efficacy of platinum by interface modification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Minh-Hai; Pai, Chi-Feng; Nguyen, Kayla X.

2015-06-01

We report a strong enhancement of the efficacy of the spin Hall effect (SHE) of Pt for exerting anti-damping spin torque on an adjacent ferromagnetic layer by the insertion of ≈0.5 nm layer of Hf between a Pt film and a thin, ≤2 nm, Fe{sub 60}Co{sub 20}B{sub 20} ferromagnetic layer. This enhancement is quantified by measurement of the switching current density when the ferromagnetic layer is the free electrode in a magnetic tunnel junction. The results are explained as the suppression of spin pumping through a substantial decrease in the effective spin-mixing conductance of the interface, but without a concomitant reduction ofmore » the ferromagnet's absorption of the SHE generated spin current.« less

ARC length control for plasma welding

NASA Technical Reports Server (NTRS)

Iceland, William F. (Inventor)

1988-01-01

A control system to be used with a plasma arc welding apparatus is disclosed. The plasma arc welding apparatus includes a plasma arc power supply, a contactor, and an electrode assembly for moving the electrode relative to a work piece. The electrode assembly is raised or lowered by a drive motor. The present apparatus includes a plasma arc adapter connected across the power supply to measure the voltage across the plasma arc. The plasma arc adapter forms a dc output signal input to a differential amplifier. A second input is defined by an adjustable resistor connected to a dc voltage supply to permit operator control. The differential amplifier forms an output difference signal provided to an adder circuit. The adder circuit then connects with a power amplifier which forms the driving signal for the motor. In addition, the motor connects to a tachometor which forms a feedback signal delivered to the adder to provide damping, therby avoiding servo loop overshoot.

Mesoporous composite nickel cobalt oxide/graphene oxide synthesized via a template-assistant co-precipitation route as electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Xu, Yanjie; Wang, Lincai; Cao, Peiqi; Cai, Chuanlin; Fu, Yanbao; Ma, Xiaohua

2016-02-01

A simple co-precipitation method utilizing SDS (sodium dodecyl sulfate) as template and ammonia as precipitant is successfully employed to synthesize nickel cobalt oxide/graphene oxide (NiCo2O4/GO) composite. The as-prepared composite (NCG-10) exhibits a high capacitance of 1211.25 F g-1, 687 F g-1 at the current density of 1 A g-1, 10 A g-1 and good cycling ability which renders NCG-10 as promising electrode material for supercapacitors. An asymmetric supercapacitor (ASC) (full button cell) has been constructed with NCG-10 as positive electrode and lab-made reduced graphene oxide (rGO) as negative electrode. The fabricated NCG-10//rGO with an extended stable operational voltage of 1.6 V can deliver a high specific capacitance of 144.45 F g-1 at a current density of 1 A g-1. The as-prepared NCG-10//rGO demonstrates remarkable energy density (51.36 W h kg-1 at 1 A g-1), high power density (50 kW kg-1 at 20 A g-1). The retention of capacitance is 88.6% at the current density of 8 A g-1 after 2000 cycles. The enhanced capacitive performance can be attributed to the improved specific surface area and 3D open area of NCG-10 generated by the pores and channels with the substantial function of SDS.

View of button board which accommodates the 1200 button switches ...

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

View of button board which accommodates the 1200 button switches which manually control the indicating pilot lights on the model board. Not all switches are active, some switches were installed for a planned, but never constructed, system expansion. - Thirtieth Street Station, Load Dispatch Center, Thirtieth & Market Streets, Railroad Station, Amtrak (formerly Pennsylvania Railroad Station), Philadelphia, Philadelphia County, PA

A fast button surface defects detection method based on convolutional neural network

NASA Astrophysics Data System (ADS)

Liu, Lizhe; Cao, Danhua; Wu, Songlin; Wu, Yubin; Wei, Taoran

2018-01-01

Considering the complexity of the button surface texture and the variety of buttons and defects, we propose a fast visual method for button surface defect detection, based on convolutional neural network (CNN). CNN has the ability to extract the essential features by training, avoiding designing complex feature operators adapted to different kinds of buttons, textures and defects. Firstly, we obtain the normalized button region and then use HOG-SVM method to identify the front and back side of the button. Finally, a convolutional neural network is developed to recognize the defects. Aiming at detecting the subtle defects, we propose a network structure with multiple feature channels input. To deal with the defects of different scales, we take a strategy of multi-scale image block detection. The experimental results show that our method is valid for a variety of buttons and able to recognize all kinds of defects that have occurred, including dent, crack, stain, hole, wrong paint and uneven. The detection rate exceeds 96%, which is much better than traditional methods based on SVM and methods based on template match. Our method can reach the speed of 5 fps on DSP based smart camera with 600 MHz frequency.

Emotive concept nouns and motor responses: attraction or repulsion?

PubMed

Freina, Laura; Baroni, Giulia; Borghi, Anna M; Nicoletti, Roberto

2009-06-01

We carried out three experiments aimed at testing whether hand posture affects the compatibility effect that Chen and Bargh (1999) found between a word's emotional connotation and arm movement direction. In the present study, participants responded by pressing two buttons: one placed near their body, the other far away. In Experiment 1, in which they pressed the response button with their hand open, RTs were shorter when participants pressed the far button for positive words and the near button for negative words, as if they simulated reaching for something good and avoiding something bad. However, in Experiments 2 and 3, in which participants pressed the response button with a tennis ball in their hand, RTs were shorter when participants pressed the near button for positive words and the far button for negative words, as if they simulated drawing a good thing closer and pushing a bad thing away. Results are discussed within the framework of theories on concept grounding in emotion and action systems.

Air-Coupled Ultrasonic Receivers with High Electromechanical Coupling PMN-32%PT Strip-Like Piezoelectric Elements

PubMed Central

Kazys, Rymantas J.; Sliteris, Reimondas; Sestoke, Justina

2017-01-01

For improvement of the efficiency of air-coupled ultrasonic transducers PMN-32%PT piezoelectric crystals which possess very high piezoelectric properties may be used. The electromechanical coupling factor of such crystals for all main vibration modes such as the thickness extension and transverse extension modes is more than 0.9. Operation of ultrasonic transducers with such piezoelectric elements in transmitting and receiving modes is rather different. Therefore, for transmission and reception of ultrasonic signals, separate piezoelectric elements with different dimensions must be used. The objective of this research was development of novel air-coupled ultrasonic receivers with PMN-32%PT strip-like piezoelectric elements vibrating in a transverse-extension mode with electromechanically controlled operation and suitable for applications in ultrasonic arrays. Performance of piezoelectric receivers made of the PMN-32%PT strip-like elements vibrating in this mode may be efficiently controlled by selecting geometry of the electrodes covering side surfaces of the piezoelectric element. It is equivalent to introduction of electromechanical damping which does not require any additional backing element. For this purpose; we have proposed the continuous electrodes to divide into two pairs of electrodes. The one pair is used to pick up the electric signal; another one is exploited for electromechanical damping. Two types of electrodes may be used—rectangular or non-rectangular—with a gap between them directed at some angle, usually 45°. The frequency bandwidth is wider (up to 9 kHz) in the case of non-rectangular electrodes. The strip-like acoustic matching element bonded to the tip of the PMN-32%PT crystal may significantly enhance the performance of the ultrasonic receiver. It was proposed to use for this purpose AIREX T10.110 rigid polymer foam, the acoustic impedance of which is close to the optimal value necessary for matching with air. It was found that in order to get a wide bandwidth the length of the matching strip should be selected not a quarter wavelength λ/4 at the antiresonance frequency but at lower frequency. It allowed achieving the frequency bandwidth (14–18)% with respect to the central frequency at −3 dB level. PMID:29035348

Air-Coupled Ultrasonic Receivers with High Electromechanical Coupling PMN-32%PT Strip-Like Piezoelectric Elements.

PubMed

Kazys, Rymantas J; Sliteris, Reimondas; Sestoke, Justina

2017-10-16

For improvement of the efficiency of air-coupled ultrasonic transducers PMN-32%PT piezoelectric crystals which possess very high piezoelectric properties may be used. The electromechanical coupling factor of such crystals for all main vibration modes such as the thickness extension and transverse extension modes is more than 0.9. Operation of ultrasonic transducers with such piezoelectric elements in transmitting and receiving modes is rather different. Therefore, for transmission and reception of ultrasonic signals, separate piezoelectric elements with different dimensions must be used. The objective of this research was development of novel air-coupled ultrasonic receivers with PMN-32%PT strip-like piezoelectric elements vibrating in a transverse-extension mode with electromechanically controlled operation and suitable for applications in ultrasonic arrays. Performance of piezoelectric receivers made of the PMN-32%PT strip-like elements vibrating in this mode may be efficiently controlled by selecting geometry of the electrodes covering side surfaces of the piezoelectric element. It is equivalent to introduction of electromechanical damping which does not require any additional backing element. For this purpose; we have proposed the continuous electrodes to divide into two pairs of electrodes. The one pair is used to pick up the electric signal; another one is exploited for electromechanical damping. Two types of electrodes may be used-rectangular or non-rectangular-with a gap between them directed at some angle, usually 45°. The frequency bandwidth is wider (up to 9 kHz) in the case of non-rectangular electrodes. The strip-like acoustic matching element bonded to the tip of the PMN-32%PT crystal may significantly enhance the performance of the ultrasonic receiver. It was proposed to use for this purpose AIREX T10.110 rigid polymer foam, the acoustic impedance of which is close to the optimal value necessary for matching with air. It was found that in order to get a wide bandwidth the length of the matching strip should be selected not a quarter wavelength λ/4 at the antiresonance frequency but at lower frequency. It allowed achieving the frequency bandwidth (14-18)% with respect to the central frequency at -3 dB level.

Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis.

PubMed

Neary, Kaitlin C; Mormino, Matthew A; Wang, Hongmei

2017-01-01

In stress-positive, unstable supination-external rotation type 4 (SER IV) ankle fractures, implant selection for syndesmotic fixation is a debated topic. Among the available syndesmotic fixation methods, the metallic screw and the suture button have been routinely compared in the literature. In addition to strength of fixation and ability to anatomically restore the syndesmosis, costs associated with implant use have recently been called into question. This study aimed to examine the cost-effectiveness of the suture button and determine whether suture button fixation is more cost-effective than two 3.5-mm syndesmotic screws not removed on a routine postoperative basis. Economic and decision analysis; Level of evidence, 2. Studies with the highest evidence levels in the available literature were used to estimate the hardware removal and failure rates for syndesmotic screws and suture button fixation. Costs were determined by examining the average costs for patients who underwent surgery for unstable SER IV ankle fractures at a single level-1 trauma institution. A decision analysis model that allowed comparison of the 2 fixation methods was developed. Using a 20% screw hardware removal rate and a 4% suture button hardware removal rate, the total cost for 2 syndesmotic screws was US$20,836 and the total effectiveness was 5.846. This yielded a total cost of $3564 per quality-adjusted life-year (QALY) over an 8-year time period. The total cost for suture button fixation was $19,354 and the total effectiveness was 5.904, resulting in a total cost of $3294 per QALY over the same time period. A sensitivity analysis was then conducted to assess suture button fixation costs as well as screw and suture button hardware removal rates. Other possible treatment scenarios were also examined, including 1 screw and 2 suture buttons for operative fixation of the syndesmosis. To become more cost-effective, the screw hardware removal rate would have to be reduced to less than 10%. Furthermore, fixation with a single suture button continued to be the dominant treatment strategy compared with 2 suture buttons, 1 screw, and 2 screws for syndesmotic fixation. This cost-effectiveness analysis suggests that for unstable SER IV ankle fractures, suture button fixation is more cost-effective than syndesmotic screws not removed on a routine basis. Suture button fixation was a dominant treatment strategy, because patients spent on average $1482 less and had a higher quality of life by 0.058 QALYs compared with patients who received fixation with 2 syndesmotic screws. Assuming that functional outcomes and failure rates were equivalent, screw fixation only became more cost-effective when the screw hardware removal rate was reduced to less than 10% or when the suture button cost exceeded $2000. In addition, fixation with a single suture button device proved more cost-effective than fixation with either 1 or 2 syndesmotic screws.

The Emerging Role of 3-Dimensional Printing in Rhinology.

PubMed

Stokken, Janalee K; Pallanch, John F

2017-06-01

Nasal septal perforations, particularly those that are large and irregular in shape, often present as challenging surgical dilemmas. New technology has allowed us to develop techniques using computed tomography imaging and 3-dimensional (3D) printers to design custom polymeric silicone septal buttons. These buttons offer patients an option that avoids a surgical intervention when standard buttons do not fit well or are not tolerated. Preliminary data suggest that buttons designed by 3D printer technology provide more comfort than standard commercially available or hand-carved buttons with equivalent reduction of symptoms. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of the Blue Button Online Tool for Sharing Health Information: Qualitative Interviews With Patients and Providers.

PubMed

Klein, Dawn M; Fix, Gemmae M; Hogan, Timothy P; Simon, Steven R; Nazi, Kim M; Turvey, Carolyn L

2015-08-18

Information sharing between providers is critical for care coordination, especially in health systems such as the United States Department of Veterans Affairs (VA), where many patients also receive care from other health care organizations. Patients can facilitate this sharing by using the Blue Button, an online tool that promotes patients' ability to view, print, and download their health records. The aim of this study was to characterize (1) patients' use of Blue Button, an online information-sharing tool in VA's patient portal, My HealtheVet, (2) information-sharing practices between VA and non-VA providers, and (3) how providers and patients use a printed Blue Button report during a clinical visit. Semistructured qualitative interviews were conducted with 34 VA patients, 10 VA providers, and 9 non-VA providers. Interviews focused on patients' use of Blue Button, information-sharing practices between VA and non-VA providers, and how patients and providers use a printed Blue Button report during a clinical visit. Qualitative themes were identified through iterative rounds of coding starting with an a priori schema based on technology adoption theory. Information sharing between VA and non-VA providers relied primarily on the patient. Patients most commonly used Blue Button to access and share VA laboratory results. Providers recognized the need for improved information sharing, valued the Blue Button printout, and expressed interest in a way to share information electronically across settings. Consumer-oriented technologies such as Blue Button can facilitate patients sharing health information with providers in other health care systems; however, more education is needed to inform patients of this use to facilitate care coordination. Additional research is needed to explore how personal health record documents, such as Blue Button reports, can be easily shared and incorporated into the clinical workflow of providers.

Development of procedures for calculating stiffness and damping of elastomers in engineering applications, part 6

NASA Technical Reports Server (NTRS)

Rieger, A.; Burgess, G.; Zorzi, E.

1980-01-01

An elastomer damper was designed, tested, and compared with the performance of a hydraulic damper for a power transmission shaft. The six button Viton-70 damper was designed so that the elastomer damper or the hydraulic damper could be activated without upsetting the imbalance condition of the assembly. This permitted a direct comparison of damper effectiveness. The elastomer damper consistently performed better than the hydraulic mount and permitted stable operation of the power transmission shaft to speeds higher than obtained with the squeeze film damper. Tests were performed on shear specimens of Viton-79, Buna-N, EPDM, and Neoprene to determine performance limitations imposed by strain, temperature, and frequency. Frequencies of between 110 Hz and 1100 Hz were surveyed with imposed strains between 0.0005 and 0.08 at temperatures of 32 C, 66 C, and 80 C. A set of design curves was generated in a unified format for each of the elastomer materials.

Virtual button interface

DOEpatents

Jones, Jake S.

1999-01-01

An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch.

Effect of blood contamination on shear bond strength of orthodontic brackets and disinclusion buttons.

PubMed

Sfondrini, Maria Francesca; Gatti, Sara; Scribante, Andrea

2011-07-01

Our aim was to assess the effect of blood contamination on the shear bonding strength and sites of failure of orthodontic brackets and bondable buttons. We randomly divided 160 bovine permanent mandibular incisors into 8 groups of 20 specimens each. Both orthodontic brackets (Step brackets, Leone, Sesto Fiorentino, Italy) and bondable buttons (Flat orthodontic buttons, Leone, Sesto Fiorentino, Italy) were tested on four different enamel surfaces: dry; contamination with blood before priming; after priming; and before and after priming. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bonding strength and the rate of adhesive failures were recorded. Data were analysed using the analysis of variance (ANOVA), Scheffè tests, and the chi-square test. Uncontaminated enamel surfaces showed the highest bonding strengths for both brackets and buttons. When they were contaminated with blood, orthodontic brackets had significantly lower shear strengths than bondable buttons (P=0.0001). There were significant differences in sites of failure among the groups for the various enamel surfaces (P=0.001). Contamination of enamel by blood during bonding lowers the strength of the bond, more so with orthodontic brackets than with bondable buttons. Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Widgets and Buttons

MedlinePlus

... Home → Widgets and Buttons URL of this page: https://medlineplus.gov/widgets.html Widgets and Buttons To ... link the word MedlinePlus to the MedlinePlus homepage ( https://medlineplus.gov/ ). Search MedlinePlus : To put the MedlinePlus ...

Shear bond strength of orthodontic brackets and disinclusion buttons: effect of water and saliva contamination.

PubMed

Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola; Scribante, Andrea

2013-01-01

The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons.

Virtual button interface

DOEpatents

Jones, J.S.

1999-01-12

An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment are disclosed. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch. 4 figs.

EEG alpha activity and hallucinatory experience during sensory deprivation.

PubMed

Hayashi, M; Morikawa, T; Hori, T

1992-10-01

The relationship between hallucinatory experiences under sensory deprivation and EEG alpha activities was studied. Each of seven male students lived alone in an air conditioned, soundproof dark room for 72 hours. When hallucinatory experiences occurred, the students pressed a button at once. If they could not press the button during the experience, they were required to press it two times when the hallucinatory experience was finished. Spectral analysis was performed on the consecutive EEG samples from just before button-presses to 10 min. before them, and the average alpha band amplitudes were obtained for the four epochs (0-.5, .5-2, 2-5, 5-10 min.). For the single button-presses, the amplitude of alpha band increased 2 min. before the button-presses. Right-hemisphere EEG activation was observed in the occipital area for the double button-presses. The results suggest an association between the hallucinatory experiences under sensory deprivation and the amount of EEG alpha activity.

The anesthetic management of button battery ingestion in children.

PubMed

Ing, Richard J; Hoagland, Monica; Mayes, Lena; Twite, Mark

2018-03-01

Injuries related to button battery ingestion are common in children. This review provides an outline of the epidemiology, pathophysiology, management, and anesthetic implications in children who have ingested a button battery. A literature search was conducted in the United States National Library of Medicine PubMed database using the terms "button battery ingestion" and "children' and "removal" and "surgery" and "anesthesia". Ninety-six articles published in English were found from 1983-2017, and 62 of these articles were incorporated into this review. Additionally, the Internet was searched with the terms "button battery ingestion and children" to identify further entities, organizations, and resources affiliated with button battery ingestion in children. These additional sources were studied and included in this review. Button batteries are ubiquitous in homes and electronic devices. Since 2006, larger-diameter and higher-voltage batteries have become available. These are more likely to become impacted in the esophagus after ingestion and lead to an increase in severe morbidity and mortality due to caustic tissue injury. Children at the highest risk for complications are those under six years of age who have ingested batteries > 20 mm in diameter and sustain prolonged esophageal impaction at the level of the aortic arch with the negative pole oriented anteriorly. Anesthesiologists need to know about the epidemiology, pathophysiology, complications, and anesthetic management of children who have ingested button batteries.

Subcortical roles in lexical task processing: Inferences from thalamic and subthalamic event-related potentials.

PubMed

Tiedt, Hannes O; Ehlen, Felicitas; Krugel, Lea K; Horn, Andreas; Kühn, Andrea A; Klostermann, Fabian

2017-01-01

Subcortical functions for language capacities are poorly defined, but may be investigated in the context of deep brain stimulation. Here, we studied event-related potentials recorded from electrodes in the subthalamic nucleus (STN) and the thalamic ventral intermediate nucleus (VIM) together with surface-EEG. Participants completed a lexical decision task (LDT), which required the differentiation of acoustically presented words from pseudo-words by button press. Target stimuli were preceded by prime-words. In recordings from VIM, a slow potential shift apparent at the lower electrode contacts persisted during target stimulus presentation (equally for words and pseudo-words). In contrast, recordings from STN electrodes showed a short local activation on prime-words but not target-stimuli. In both depth-recording regions, further components related to contralateral motor responses to target words were evident. On scalp level, mid-central activations on (pseudo)lexical stimuli were obtained, in line with the expression of N400 potentials. The prolonged activity recorded from VIM, exclusively accompanying the relevant LDT phase, is in line with the idea of thalamic "selective engagement" for supporting the realization of the behavioral focus demanded by the task. In contrast, the phasic prime related activity rather indicates "procedural" STN functions, for example, for trial sequencing or readiness inhibition of prepared target reactions. Hum Brain Mapp 38:370-383, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Use of the Blue Button Online Tool for Sharing Health Information: Qualitative Interviews With Patients and Providers

PubMed Central

Fix, Gemmae M; Hogan, Timothy P; Simon, Steven R; Nazi, Kim M; Turvey, Carolyn L

2015-01-01

Background Information sharing between providers is critical for care coordination, especially in health systems such as the United States Department of Veterans Affairs (VA), where many patients also receive care from other health care organizations. Patients can facilitate this sharing by using the Blue Button, an online tool that promotes patients’ ability to view, print, and download their health records. Objective The aim of this study was to characterize (1) patients’ use of Blue Button, an online information-sharing tool in VA’s patient portal, My HealtheVet, (2) information-sharing practices between VA and non-VA providers, and (3) how providers and patients use a printed Blue Button report during a clinical visit. Methods Semistructured qualitative interviews were conducted with 34 VA patients, 10 VA providers, and 9 non-VA providers. Interviews focused on patients’ use of Blue Button, information-sharing practices between VA and non-VA providers, and how patients and providers use a printed Blue Button report during a clinical visit. Qualitative themes were identified through iterative rounds of coding starting with an a priori schema based on technology adoption theory. Results Information sharing between VA and non-VA providers relied primarily on the patient. Patients most commonly used Blue Button to access and share VA laboratory results. Providers recognized the need for improved information sharing, valued the Blue Button printout, and expressed interest in a way to share information electronically across settings. Conclusions Consumer-oriented technologies such as Blue Button can facilitate patients sharing health information with providers in other health care systems; however, more education is needed to inform patients of this use to facilitate care coordination. Additional research is needed to explore how personal health record documents, such as Blue Button reports, can be easily shared and incorporated into the clinical workflow of providers. PMID:26286139

Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination

PubMed Central

Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola

2013-01-01

Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Results. Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons. PMID:23762825

Evaluation of Heat Dissipation in the BPM Buttons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinayev,I.; Blednyhk, A.

2009-05-04

Growth of circulating current in the storage rings drastically increases heating of the beam position monitor (BPM) buttons due to the induced trapped modes is drastically increasing. Excessive heating can lead to the errors in the measuring of beam position or even catastrophic failures of the pick-up assembly. In this paper we present calculations of heat generated in the button for different geometries and materials. The obtained results are used for the optimization of the NSLS-II BPM buttons design.

Comparative Study of button BPM Trapped Mode Heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron,P.; Singh, O.

2009-05-04

The combination of short bunches and high currents found in modern light sources and colliders can result in the deposition of tens of watts of power in BPM buttons. The resulting thermal distortion is potentially problematic for maintaining high precision beam position stability, and in the extreme case can result in mechanical damage. We present a simple algorithm that uses the input parameters of beam current, bunch length, button diameter, beampipe aperture, and fill pattern to calculate a relative figure-of-merit for button heating. Data for many of the world's light sources and colliders is compiled in a table. Using themore » algorithm, the table is sorted in order of the relative magnitude of button heating.« less

Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

PubMed

Dukic, T; Hanson, L; Falkmer, T

2006-01-15

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

Lower complication rate and faster return to sports in patients with acute syndesmotic rupture treated with a new knotless suture button device.

PubMed

Colcuc, Christian; Blank, Marc; Stein, Thomas; Raimann, Florian; Weber-Spickschen, Sanjay; Fischer, Sebastian; Hoffmann, Reinhard

2017-12-09

Suture button devices for tibiofibular syndesmosis injuries provide semirigid dynamic stabilization, but complications including knot irritation have been reported. No randomized trials of the new knotless suture button devices have been performed. We hypothesized that knotless suture button devices eliminate knot irritation and facilitate quicker return to sports. This study was performed to compare the clinical outcomes, complication rates, and time to return to sports between a new knotless suture button device and syndesmotic screw fixation. This study included 54 patients treated for ankle syndesmotic injury from 2012 to 2014 with a knotless suture button device or syndesmotic screw fixation. Clinical outcomes were measured using the American Orthopaedics Foot and Ankle Society score, Foot and Ankle Disability Index, Olerud and Molander score, and visual analog scale for pain and function. Secondary outcome measures were the complication rate and time required to return to sports. Patients underwent clinical and radiological evaluations preoperatively and three times during the 1-year postoperative follow-up. 54 of 62 eligible patients were analyzed, median age 37 (18-60) and underwent the 1-year follow-up. The screw fixation and knotless suture button groups comprised 26 and 28 patients, respectively. The complication rate was significantly lower (p = 0.03) and time to return to sports was significantly shorter in the knotless suture button than screw fixation group (average, 14 versus 19 weeks, respectively; p = 0.006). No significant differences were identified in clinical outcomes or visual analog scale scores for pain and function between the groups. Age, injury mechanism, and body mass index did not significantly affect the time required to return to sports activities. The type of fixation was the only independent variable that reached statistical significance (p = 0.006). Syndesmotic screw fixation and the new knotless suture button device both resulted in good clinical results. Lower complication rate and the earlier time to return to sports make the new knotless suture button device recommendable especially for highly active patients. Randomized controlled trial, Level I.

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... on its top with a friction striking material which shall, by a pull of the tear strip, be entirely exposed for striking the friction igniter button. The igniter button shall be non-water soluble or be... manner as to provide positive ignition by the friction striker. The igniter button shall be firmly...

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... on its top with a friction striking material which shall, by a pull of the tear strip, be entirely exposed for striking the friction igniter button. The igniter button shall be non-water soluble or be... manner as to provide positive ignition by the friction striker. The igniter button shall be firmly...

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... on its top with a friction striking material which shall, by a pull of the tear strip, be entirely exposed for striking the friction igniter button. The igniter button shall be non-water soluble or be... manner as to provide positive ignition by the friction striker. The igniter button shall be firmly...

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... on its top with a friction striking material which shall, by a pull of the tear strip, be entirely exposed for striking the friction igniter button. The igniter button shall be non-water soluble or be... manner as to provide positive ignition by the friction striker. The igniter button shall be firmly...

Distal Attachment of Flexor Tendon Allograft: A Biomechanical Study of Different Reconstruction Techniques in Human Cadaver Hands

PubMed Central

Wei, Zhuang; Thoreson, Andrew R.; Amadio, Peter C.; An, Kai-Nan; Zhao, Chunfeng

2014-01-01

We compared the mechanical force of tendon-to-bone repair techniques for flexor tendon reconstruction. Thirty-six flexor digitorum profundus (FDP) tendons were divided into three groups based upon the repair technique: (1) suture/button repair using FDP tendon (Pullout button group), (2) suture bony anchor using FDP tendon (Suture anchor group), and (3) suture/button repair using FDP tendon with its bony attachment preserved (Bony attachment group). The repair failure force and stiffness were measured. The mean load to failure and stiffness in the bony attachment group were significantly higher than that in the pullout button and suture anchor groups. No significant difference was found in failure force and stiffness between the pullout button and suture anchor groups. An intrasynovial flexor tendon graft with its bony attachment has significantly improved tensile properties at the distal repair site when compared with a typical tendon-to-bone attachment with a button or suture anchor. The improvement in the tensile properties at the repair site may facilitate postoperative rehabilitation and reduce the risk of graft rupture. PMID:23754507

Results from a Test Fixture for button BPM Trapped Mode Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron,P.; Bacha, B.; Blednykh, A.

2009-05-04

A variety of measures have been suggested to mitigate the problem of button BPM trapped mode heating. A test fixture, using a combination of commercial-off-the-shelf and custom machined components, was assembled to validate the simulations. We present details of the fixture design, measurement results, and a comparison of the results with the simulations. A brief history of the trapped mode button heating problem and a set of design rules for BPM button optimization are presented elsewhere in these proceedings. Here we present measurements on a test fixture that was assembled to confirm, if possible, a subset of those rules: (1)more » Minimize the trapped mode impedance and the resulting power deposited in this mode by the beam. (2) Maximize the power re-radiated back into the beampipe. (3) Maximize electrical conductivity of the outer circumference of the button and minimize conductivity of the inner circumference of the shell, to shift power deposition from the button to the shell. The problem is then how to extract useful and relevant information from S-parameter measurements of the test fixture.« less

Nasal foreign bodies in children: should they have a plain radiograph in the accident and emergency?

PubMed

Glynn, Fergal; Amin, Mohamed; Kinsella, John

2008-04-01

To determine the proportion of children with nasal foreign bodies who had button batteries as the foreign body. To describe the clinical care and outcome of those children with a button battery foreign body. A retrospective review of all children presenting to the accident and emergency room with a nasal foreign body or unilateral nasal discharge during a 6-month period was assessed. Forty-four children were included. The most common object found was a plastic bead (27%), followed by foam, paper, or tissue fragments (23%); food matter represented 15%. A button battery was found in 3 patients (7%); other foreign bodies included stones, buttons, crayons, erasers, and a pellet. Thiry-six (82%) had their foreign body removed without anesthetic and 8 (18%) required a general anesthetic. All 3 children with a button battery went undiagnosed until examination in the operating theater. Because there was no previous indication of the presence of a button battery in the 3 children, the removal of the foreign body under general anesthesia was scheduled for the following day. The removal of the button batteries would have been expedited had a plain radiograph been obtained, possibly resulting in less morbidity for our patients. We recommend a plain radiograph in all children presenting with a nonvisible foreign body or unilateral nasal discharge.

MEMBRANE POTENTIAL OF THE SQUID GIANT AXON DURING CURRENT FLOW

PubMed Central

Cole, Kenneth S.; Curtis, Howard J.

1941-01-01

The squid giant axon was placed in a shallow narrow trough and current was sent in at two electrodes in opposite sides of the trough and out at a third electrode several centimeters away. The potential difference across the membrane was measured between an inside fine capillary electrode with its tip in the axoplasm between the pair of polarizing electrodes, and an outside capillary electrode with its tip flush with the surface of one polarizing electrode. The initial transient was roughly exponential at the anode make and damped oscillatory at the sub-threshold cathode make with the action potential arising from the first maximum when threshold was reached. The constant change of membrane potential, after the initial transient, was measured as a function of the total polarizing current and from these data the membrane potential is obtained as a function of the membrane current density. The absolute value of the resting membrane resistance approached at low polarizing currents is about 23 ohm cm.2. This low value is considered to be a result of the puncture of the axon. The membrane was found to be an excellent rectifier with a ratio of about one hundred between the high resistance at the anode and the low resistance at the cathode for the current range investigated. On the assumption that the membrane conductance is a measure of its ion permeability, these experiments show an increase of ion permeability under a cathode and a decrease under an anode. PMID:19873234

The Blue Button Project: Engaging Patients in Healthcare by a Click of a Button.

PubMed

Mohsen, Mona Omar; Aziz, Hassan A

2015-01-01

The Blue Button project has become a way for many Americans to download their health records by just a click in any way that suits them, such as in print, on a thumb drive, or on their mobile devices and smartphones. Several organizations have developed and applied Blue Buttons on their websites to allow beneficiaries to securely access and view personal medical information and claims. The purpose of this literature review is to highlight the significance of the Blue Button project in the field of health information management. Findings suggest that the project could empower and engage consumers and patients in a healthcare system by allowing access to medical records, thereby promoting better management and overall improvement of their healthcare. To date, the project has gained wide support from insurers, technology companies, and health providers despite the challenges of standardization and interoperability.

BPM Button Optimization to Minimize Distortion Due to Trapped Mode Heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron,P.; Blednyk, A.; Kosciuk, B.

2009-05-04

The outer circumference of a BPM button and the inner circumference of the button housing comprise a transmission line. This transmission line typically presents an impedance of a few tens of ohms to the beam, and couples very weakly to the 50 ohm coaxial transmission line that comprises the signal path out of the button. The modes which are consequently excited and trapped often have quality factors of several hundred, permitting resonant excitation by the beam. The thermal distortion resulting from trapped mode heating is potentially problematic for achieving the high precision beam position measurements needed to provide the sub-micronmore » beam position stability required by light source users. We present a button design that has been optimized via material selection and component geometry to minimize both the trapped mode heating and the resulting thermal distortion.« less

The Blue Button Project: Engaging Patients in Healthcare by a Click of a Button

PubMed Central

Mohsen, Mona Omar; Aziz, Hassan A.

2015-01-01

The Blue Button project has become a way for many Americans to download their health records by just a click in any way that suits them, such as in print, on a thumb drive, or on their mobile devices and smartphones. Several organizations have developed and applied Blue Buttons on their websites to allow beneficiaries to securely access and view personal medical information and claims. The purpose of this literature review is to highlight the significance of the Blue Button project in the field of health information management. Findings suggest that the project could empower and engage consumers and patients in a healthcare system by allowing access to medical records, thereby promoting better management and overall improvement of their healthcare. To date, the project has gained wide support from insurers, technology companies, and health providers despite the challenges of standardization and interoperability. PMID:26755898

Esophageal button battery ingestions: decreasing time to operative intervention by level I trauma activation.

PubMed

Russell, Robert T; Griffin, Russell L; Weinstein, Elizabeth; Billmire, Deborah F

2014-09-01

The incidence of button battery ingestions is increasing and injury due to esophageal impaction begins within minutes of exposure. We changed our management algorithm for suspected button battery ingestions with intent to reduce time to evaluation and operative removal. A retrospective study was performed to identify and evaluate time to treatment and outcome for all esophageal button battery ingestions presenting to a major children's hospital emergency room from February 1, 2010 through February 1, 2012. During the first year, standard emergency room triage (ST) was used. During the second year, the triage protocol was changed and Trauma I triage (TT) was used. 24 children had suspected button battery ingestions with 11 having esophageal impaction. One esophageal impaction was due to 2 stacked coins. Time from arrival in emergency room to battery removal was 183minutes in ST group (n=4) and 33minutes in TT group (n=7) (p=0.04). One patient in ST developed a tracheoesophageal fistula. There were no complications in the TT group. The use of Trauma 1 activations for suspected button battery ingestions has led to more expedient evaluation and shortened time to removal of impacted esophageal batteries. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of Cognitive Function of Children with Developmental Disabilities by means of Button-Press Task

NASA Astrophysics Data System (ADS)

Nakazono, Shogo; Kobori, Satoshi

The button-press task means that the subject observes a moving target and presses a button to stop it when the target enters a specified area on a computer display. Subjects perform normal task, suppressed task and delayed task. In the suppressed task, the moving target disappears at some point during the trial. In the delayed task, there is some lag time between the time of pressing button and of stopping target. In these tasks, subjects estimate the movement of the target, and press the button considering his/her own reaction time. In our previous study, we showed that cognitive and motor function was able to be evaluated by these tasks. In this study, we examined error data of children with developmental disabilities to evaluate the cognitive function, and investigated the learning processes. Moreover, we discussed the developmental stages by comparing the children with disabilities to normal control children, and we clarified the behavior characteristics of children with developmental disabilities. Asa result, it was shown that our evaluation method and system for the button-press task were effective to evaluate cognitive ability of children with developmental disabilities.

Parametrically disciplined operation of a vibratory gyroscope

NASA Technical Reports Server (NTRS)

Shcheglov, Kirill V. (Inventor); Challoner, A. Dorian (Inventor); Hayworth, Ken J. (Inventor); Peay, Chris S. (Inventor)

2008-01-01

Parametrically disciplined operation of a symmetric nearly degenerate mode vibratory gyroscope is disclosed. A parametrically-disciplined inertial wave gyroscope having a natural oscillation frequency in the neighborhood of a sub-harmonic of an external stable clock reference is produced by driving an electrostatic bias electrode at approximately twice this sub-harmonic frequency to achieve disciplined frequency and phase operation of the resonator. A nearly symmetric parametrically-disciplined inertial wave gyroscope that can oscillate in any transverse direction and has more than one bias electrostatic electrode that can be independently driven at twice its oscillation frequency at an amplitude and phase that disciplines its damping to zero in any vibration direction. In addition, operation of a parametrically-disciplined inertial wave gyroscope is taught in which the precession rate of the driven vibration pattern is digitally disciplined to a prescribed non-zero reference value.

Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

PubMed Central

Wang, Bing-Yu; Hsieh, Fan-Chun; Lin, Che-Yu; Chen, Shao-En; Chen, Fong-Zhi; Wu, Chia-Che

2014-01-01

In this study, we develop a clamped–clamped beam-type piezoelectric vacuum pressure sensing element. The clamped–clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10−6 to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage. PMID:25421736

Acromioclavicular joint dislocation: a Dog Bone button fixation alone versus Dog Bone button fixation augmented with acromioclavicular repair-a finite element analysis study.

PubMed

Sumanont, Sermsak; Nopamassiri, Supachoke; Boonrod, Artit; Apiwatanakul, Punyawat; Boonrod, Arunnit; Phornphutkul, Chanakarn

2018-03-20

Suspension suture button fixation was frequently used to treat acromioclavicular joint (ACJ) dislocation. However, there were many studies reporting about complications and residual horizontal instability after fixation. Our study compared the stability of ACJ after fixation between coracoclavicular (CC) fixation alone and CC fixation combined with ACJ repair by using finite element analysis (FEA). A finite element model was created by using CT images from the normal shoulder. The model 1 was CC fixation with suture button alone, and the model 2 was CC fixation with suture button combined with ACJ repair. Three different forces (50, 100, 200 N) applied to the model in three planes; inferior, anterior and posterior direction load to the acromion. The von Mises stress of the implants and deformation at ACJs was recorded. The ACJ repair in the model 2 could reduce the peak stress on the implant after applying the loading forces to the acromion which the ACJ repair could reduce the peak stress of the FiberWire at suture button about 90% when compared to model 1. And, the ACJ repair could reduce the deformation of the ACJ after applying the loading forces to the acromion in both vertical and horizontal planes. This FEA supports that the high-grade injuries of the ACJ should be treated with CC fixation combined with ACJ repair because this technique provides excellent stability in both vertical and horizontal planes and reduces stress to the suture button.

Low-Cost Avoidance Behaviors are Resistant to Fear Extinction in Humans

PubMed Central

Vervliet, Bram; Indekeu, Ellen

2015-01-01

Elevated levels of fear and avoidance are core symptoms across the anxiety disorders. It has long been known that fear serves to motivate avoidance. Consequently, fear extinction has been the primary focus in pre-clinical anxiety research for decades, under the implicit assumption that removing the motivator of avoidance (fear) would automatically mitigate the avoidance behaviors as well. Although this assumption has intuitive appeal, it has received little scientific scrutiny. The scarce evidence from animal studies is mixed, while the assumption remains untested in humans. The current study applied an avoidance conditioning protocol in humans to investigate the effects of fear extinction on the persistence of low-cost avoidance. Online danger-safety ratings and skin conductance responses documented the dynamics of conditioned fear across avoidance and extinction phases. Anxiety- and avoidance-related questionnaires explored individual differences in rates of avoidance. Participants first learned to click a button during a predictive danger signal, in order to cancel an upcoming aversive electrical shock (avoidance conditioning). Next, fear extinction was induced by presenting the signal in the absence of shocks while button-clicks were prevented (by removing the button in Experiment 1, or by instructing not to click the button in Experiment 2). Most importantly, post-extinction availability of the button caused a significant return of avoidant button-clicks. In addition, trait-anxiety levels correlated positively with rates of avoidance during a predictive safety signal, and with the rate of pre- to post-extinction decrease during this signal. Fear measures gradually decreased during avoidance conditioning, as participants learned that button-clicks effectively canceled the shock. Preventing button-clicks elicited a sharp increase in fear, which subsequently extinguished. Fear remained low during avoidance testing, but danger-safety ratings increased again when button-clicks were subsequently prevented. Together, these results show that low-cost avoidance behaviors can persist following fear extinction and induce increased threat appraisal. On the other hand, fear extinction did reduce augmented rates of unnecessary avoidance during safety in trait-anxious individuals, and instruction-based response prevention was more effective than removal of response cues. More research is needed to characterize the conditions under which fear extinction might mitigate avoidance. PMID:26733837

Environmental stability of high-mobility indium-oxide based transparent electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tohsophon, Thanaporn; Dabirian, Ali; De Wolf, Stefaan

2015-11-01

Large-scale deployment of a wide range of optoelectronic devices, including solar cells, critically depends on the long-term stability of their front electrodes. Here, we investigate the performance of Sn-doped In{sub 2}O{sub 3} (ITO), H-doped In{sub 2}O{sub 3} (IO:H), and Zn-doped In{sub 2}O{sub 3} (IZO) electrodes under damp heat (DH) conditions (85 °C, 85% relative humidity). ITO, IO:H capped with ITO, and IZO show high stability with only 3%, 9%, and 13% sheet resistance (R{sub s}) degradation after 1000 h of DH, respectively. For uncapped IO:H, we find a 75% R{sub s} degradation, due to losses in electron Hall mobility (μ{sub Hall}).more » We propose that this degradation results from chemisorbed OH- or H{sub 2}O-related species in the film, which is confirmed by thermal desorption spectroscopy and x-ray photoelectron spectroscopy. While μ{sub Hall} strongly degrades during DH, the optical mobility (μ{sub optical}) remains unchanged, indicating that the degradation mainly occurs at grain boundaries.« less

Modeling the impact of pedestrian behavior diversity on traffic dynamics at a crosswalk with push button

NASA Astrophysics Data System (ADS)

Xie, Dong-Fan; Zhao, Xiao-Mei; Li, Xin-Gang; Zhu, Tai-Lang

2016-01-01

Crosswalk with push button is prevalent in lots of cities for the purpose of promoting the efficiency of the crosswalk, and thus the delays of both vehicles and pedestrians can be reduced. This strategy has been confirmed to be effective in several developed countries. However, it is a pity that application of push button is aborted in some cities in China. In this work, diverse behaviors of vehicles and pedestrians are analyzed and discussed. Then, a microscopic model is developed by incorporating the interaction between vehicles and pedestrians. Numerical simulations are performed to reveal the characteristics of traffic flow and the efficiency of the signal control strategy. Also, the impacts of risker proportion and button reaction time, as well as the impacts of various behaviors as mass behavior, the patience of pedestrian and push button habit are investigated. It is expected that the results will be helpful to the strategy design of a signalized crosswalk in such developing countries as China.

Management of nasal septal perforation using silicone nasal septal button

PubMed Central

Mullace, M; Gorini, E; Sbrocca, M; Artesi, L; Mevio, N

2006-01-01

Summary Nasal septal perforation may present with various symptoms: epistaxis, crusting, secondary infection, whistling and nasal obstruction. Perforation may be treated by conservative pharmacological treatment or closed by surgical approach. A useful alternative is mechanical obturation, achieved inserting a prosthesis. The present report refers to a study on 15 patients (10 male, 5 female, mean age 38.5 years) treated by insertion of a one-piece or two-piece silicone septal button (Xomed). In the follow-up period, insertion of the nasal button reduced epistaxis, eliminated whistling during inspiration, and reduced nasal obstruction and crusting around the margin of the perforation. Contraindications are presence of acute infection with osteitis, chronic septal disease (Wegener), neoplasia and extremely large perforations. The latest buttons appear to be superior to the conventional type on account of plasticity and adaptability which offer greater conformity to the septum. This study also reveals that the new septal button is well tolerated by patients. PMID:18236638

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

PubMed

Kohrs, Christin; Hrabal, David; Angenstein, Nicole; Brechmann, André

2014-11-01

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision. Copyright © 2014 Society for Psychophysiological Research.

How to Use This Website | USDA Plant Hardiness Zone Map

Science.gov Websites

, regional or national plant hardiness zone maps in three different resolutions using the following steps. To default printing menu option or button. Viewing the Map - Open Full Map Button c. Save Full Map Button can copy the e-mail address and paste it into a different e-mail client (e.g., Google Gmail, Yahoo

Modification of Shirt Buttons for Retrospective Radiation Dosimetry after a Radiological Event

PubMed Central

Marino, Stephen A.; Johnson, Gary W.; Schiff, Peter B.; Brenner, David J.

2010-01-01

Preliminary results are presented for a personal radiation dosimeter in the form of a clothing button to provide gamma-ray dose estimation for clinically significant external radiation exposures to the general public due to a radiological incident, such as a Radiological Dispersal Device. Rods of thermoluminescent material (LiF:Mg,Ti and LiF:Mg,Cu,P) were encapsulated in plastic “buttons”, attached to shirts, and subjected to three cycles of home or commercial laundering or dry cleaning, including ironing or pressing. The buttons were subsequently exposed to doses of 137Cs gamma rays ranging from 0.75 to 8.2 Gy. The rods were removed from the buttons and their light output compared to their responses when bare or to the responses of a set of calibration rods of the same type and from the same manufacturer. In all three of the comparisons for LiF:Mg,Ti rods the relative responses of the rods in buttons changed by 2-6% relative to the same rods before cleaning. In both comparisons for LiF:Mg,Cu,P rods, the response of laundered rods was 1-3% lower than for the same rods before cleaning. Both these materials are potential candidates for button dosimeters. PMID:21451325

Esophageal button battery ingestion in children.

PubMed

Şencan, Arzu; Genişol, İncinur; Hoşgör, Münevver

2017-07-01

Button battery lodged in the esophagus carries a high risk of morbidity and mortality. The purpose of this study was to present cases of patients with esophageal button battery ingestion treated at our clinic and to emphasize the importance of early diagnosis and treatment. Records of patients admitted to our hospital for foreign body ingestion between January 2010 and May 2015 were retrospectively reviewed. Cases with button battery lodged in the esophagus were included in the study. Patient data regarding age, sex, length of time after ingestion until admission, presenting clinical symptoms, type and localization of the battery, management, and prognosis were analyzed. Among 1891 foreign body ingestions, 71 were localized in the esophagus, and 8 of those (11.2%) were cases of button battery ingestion. Mean age was 1.7 years. Admission was within 6 hours of ingestion in 5 cases, after 24 hours had elapsed in 2, and 1 month after ingestion in 1 case. All patients but 1 knew the history of ingestion. Prompt endoscopic removal was performed for all patients. Three patients developed esophageal stricture, which responded to dilatation. Early recognition and timely endoscopic removal is mandatory in esophageal button battery ingestion. It should be suspected in the differential diagnosis of patients with persistent respiratory and gastrointestinal symptoms.

Thermocron iButton and iBBat temperature dataloggers emit ultrasound.

PubMed

Willis, Craig K R; Jameson, Joel W; Faure, Paul A; Boyles, Justin G; Brack, Virgil; Cervone, Tom H

2009-10-01

Thermocron iButton dataloggers are widely used to measure thermal microclimates experienced by wild animals. The iBBat is a smaller version of the datalogger, also commercially available, that is used to measure animal skin or core body temperatures when attached externally or surgically implanted. Field observations of bats roosting under a bridge suggested that bats avoided locations with iButtons. A heterodyne bat detector revealed that the dataloggers emitted ultrasound which was detectable from a distance of up to 30 cm. We therefore recorded and quantified the acoustic properties [carrier frequency (Hz) and root mean square sound pressure level (dB SPL)] of iButton and iBBat dataloggers. All units emitted a 32.9 kHz pure tone that was readily picked up with a time expansion bat detector at a distance of 1 cm, and most were detected at a distance of 15 cm. The maximum amplitude of iButton dataloggers was 46.5 dB SPL at 1.0 cm-a level within the range of auditory sensitivity for most small mammals. Wrapping iButtons in plastic insulation severely attenuated the amplitude of ultrasound. Although there was a statistically significant reduction in rates of warming and cooling with insulation, this effect was small and we suggest that insulation may be a viable solution to eliminate unwanted ultrasonic noise in instances when small delays in thermal response dynamics are not a concern. We recommend behavioural studies to assess if the electronic signals emitted by iButtons are disturbing to small mammals.

Learning processes underlying avoidance of negative outcomes.

PubMed

Andreatta, Marta; Michelmann, Sebastian; Pauli, Paul; Hewig, Johannes

2017-04-01

Successful avoidance of a threatening event may negatively reinforce the behavior due to activation of brain structures involved in reward processing. Here, we further investigated the learning-related properties of avoidance using feedback-related negativity (FRN). The FRN is modulated by violations of an intended outcome (prediction error, PE), that is, the bigger the difference between intended and actual outcome, the larger the FRN amplitude is. Twenty-eight participants underwent an operant conditioning paradigm, in which a behavior (button press) allowed them to avoid a painful electric shock. During two learning blocks, participants could avoid an electric shock in 80% of the trials by pressing one button (avoidance button), or by not pressing another button (punishment button). After learning, participants underwent two test blocks, which were identical to the learning ones except that no shocks were delivered. Participants pressed the avoidance button more often than the punishment button. Importantly, response frequency increased throughout the learning blocks but it did not decrease during the test blocks, indicating impaired extinction and/or habit formation. In line with a PE account, FRN amplitude to negative feedback after correct responses (i.e., unexpected punishment) was significantly larger than to positive feedback (i.e., expected omission of punishment), and it increased throughout the blocks. Highly anxious individuals showed equal FRN amplitudes to negative and positive feedback, suggesting impaired discrimination. These results confirm the role of negative reinforcement in motivating behavior and learning, and reveal important differences between high and low anxious individuals in the processing of prediction errors. © 2017 Society for Psychophysiological Research.

Serious complications after button battery ingestion in children.

PubMed

Krom, Hilde; Visser, Margot; Hulst, Jessie M; Wolters, Victorien M; Van den Neucker, Anita M; de Meij, Tim; van der Doef, Hubert P J; Norbruis, Obbe F; Benninga, Marc A; Smit, Margot J M; Kindermann, Angelika

2018-07-01

Serious and fatal complications after button battery ingestion are increasing worldwide. The aim of this study is to describe serious complications after battery ingestion in children in the Netherlands.All pediatric gastroenterologists in the Netherlands performing upper endoscopies were asked to report all serious complications after battery ingestion in children (0-18 years) between 2008 and 2016 retrospectively.Sixteen serious complications were reported: death after massive bleeding through esophageal-aortal fistula (n = 1), esophageal-tracheal fistula (n = 5), stenosis after (suspected) perforation and mediastinitis (n = 5), (suspected) perforation and mediastinitis (n = 3), vocal cord paralysis (n = 1), and required reintubation for dyspnea and stridor (n = 1). The median time interval between ingestion and presentation was 5 (IQR 2-258) h. All children were ≤ 5 (median 1.4; IQR 0.9-2.1) years. Vomiting (31.3%), swallowing/feeding problems (31.3%), and fever (31.3%) were the most common presenting symptoms; however, 18.8% of the patients were asymptomatic (n = 1 missing). All batteries were button batteries (75% ≥ 20 mm; 18.8% < 20 mm; n = 1 missing). The batteries were removed by esophagogastroduodenoscopy (50%) and rigid endoscopy (37.5%) or surgically (12.5%). Sixteen serious complications occurred after small and large button batteries ingestion between 2008 and 2016 in both symptomatic and asymptomatic children in the Netherlands. Therefore, immediate intervention after (suspected) button battery ingestion is required. What is Known: • Button battery ingestion may result in serious and fatal complications. • Serious and fatal complications after button battery ingestion are increasing worldwide. What is New: • Sixteen serious complications after button battery ingestion occurred during 2008-2016 in children in the Netherlands. • Serious complications were also caused by small batteries (< 20 mm) in the Netherlands and also occurred in asymptomatic Dutch children.

Analytical expression for the tunnel current through the redox-mediated tunneling contact in the case of the adiabatic electron transfer at one of the working electrodes and any possible type of the electron transfer at the other electrode

NASA Astrophysics Data System (ADS)

Medvedev, Igor G.

2017-11-01

We study the tunnel current through a one-level redox molecule immersed into the electrolyte solution for the case when the coupling of the molecule to one of the working electrodes is strong while it is arbitrary to the other electrode. Using the Feynman-Vernon influence functional theory and the perturbation expansion of the effective action of the classical oscillator coupled both to the valence level of the redox molecule and to the thermal bath representing the classical fluctuations of the polarization of the solvent, we obtain, following the canonical way, the Langevin equation for the oscillator. It is found that for the aqueous electrolyte solution, the damping and the stochastic forces which arise due to the tunnel current are much smaller than those due to the thermal bath and therefore can be neglected. We estimate the higher-order corrections to the effective action and show that the Langevin dynamics takes place in this case for arbitrary parameters of the tunneling junction under the condition of the strong coupling of the redox molecule to one of the working electrodes. Then the steady-state coordinate distribution function of the oscillator resulting from the corresponding Fokker-Planck equation is the Boltzmann distribution function which is determined by the adiabatic free energy surface arising from the mean current-induced force. It enables us to obtain the expression for the tunnel current in the case when the coupling of the redox molecule to one of the working electrodes is strong while it is arbitrary to the other electrode.

Analytical expression for the tunnel current through the redox-mediated tunneling contact in the case of the adiabatic electron transfer at one of the working electrodes and any possible type of the electron transfer at the other electrode.

PubMed

Medvedev, Igor G

2017-11-21

We study the tunnel current through a one-level redox molecule immersed into the electrolyte solution for the case when the coupling of the molecule to one of the working electrodes is strong while it is arbitrary to the other electrode. Using the Feynman-Vernon influence functional theory and the perturbation expansion of the effective action of the classical oscillator coupled both to the valence level of the redox molecule and to the thermal bath representing the classical fluctuations of the polarization of the solvent, we obtain, following the canonical way, the Langevin equation for the oscillator. It is found that for the aqueous electrolyte solution, the damping and the stochastic forces which arise due to the tunnel current are much smaller than those due to the thermal bath and therefore can be neglected. We estimate the higher-order corrections to the effective action and show that the Langevin dynamics takes place in this case for arbitrary parameters of the tunneling junction under the condition of the strong coupling of the redox molecule to one of the working electrodes. Then the steady-state coordinate distribution function of the oscillator resulting from the corresponding Fokker-Planck equation is the Boltzmann distribution function which is determined by the adiabatic free energy surface arising from the mean current-induced force. It enables us to obtain the expression for the tunnel current in the case when the coupling of the redox molecule to one of the working electrodes is strong while it is arbitrary to the other electrode.

Single particle dynamics in a radio-frequency produced plasma sheath

NASA Astrophysics Data System (ADS)

Rubin-Zuzic, M.; Nosenko, V.; Zhdanov, S.; Ivlev, A.; Thomas, H.; Khrapak, S.; Couedel, L.

2018-01-01

Recently different research groups have investigated the motion of a single dust particle levitated in a rf plasma. Here we describe a highly resolved experiment where a single spherical melamine formaldehyde microparticle is suspended in the plasma sheath above the lower electrode of a capacitively coupled radio-frequency discharge at controlled pressure, power and neutral gas flow rate. The particle's horizontal oscillation is investigated, from which its neutral gas damping rate, kinetic temperature and eigenfrequency of the potential trap are measured. Compared to prior experiments we report about inhomogeneous and anisotropic velocity variations.

A PC parallel port button box provides millisecond response time accuracy under Linux.

PubMed

Stewart, Neil

2006-02-01

For psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus.

Superconducting current injection transistor with very high critical-current-density edge-junctions

NASA Astrophysics Data System (ADS)

van Zeghbroeck, B. J.

1985-03-01

A Superconducting Current Injection Transistor (Super-CIT) was fabricated with very high critical current-density edge-junctions. The junctions have a niobium base electrode and a lead-alloy counter electrode. The length of the junctions is 30 microns and the critical-current density is 190KA/sq cm. The Super-CIT has a current gain of 2, a large signal transresistance of 100 mV/A, and the turn-on delay, inferred from the junction resonance, is 7ps. The power dissipation is 3.5 microwatts and the power-delay product is 24.5aJ. Gap reduction due to heating was observed, limiting the maximum power dissipation per unit length to 1.1 microwatt/micron. Compared to lead-alloy Super-CITs, the device is five times smaller, three times faster, and has a three times larger output voltage. The damping resistor and the contact junction could also be eliminated.

From perception to action: phase-locked gamma oscillations correlate with reaction times in a speeded response task

PubMed Central

Fründ, Ingo; Busch, Niko A; Schadow, Jeanette; Körner, Ursula; Herrmann, Christoph S

2007-01-01

Background Phase-locked gamma oscillations have so far mainly been described in relation to perceptual processes such as sensation, attention or memory matching. Due to its very short latency (≈90 ms) such oscillations are a plausible candidate for very rapid integration of sensory and motor processes. Results We measured EEG in 13 healthy participants in a speeded reaction task. Participants had to press a button as fast as possible whenever a visual stimulus was presented. The stimulus was always identical and did not have to be discriminated from other possible stimuli. In trials in which the participants showed a fast response, a slow negative potential over central electrodes starting approximately 800 ms before the response and highly phase-locked gamma oscillations over central and posterior electrodes between 90 and 140 ms after the stimulus were observed. In trials in which the participants showed a slow response, no slow negative potential was observed and phase-locked gamma oscillations were significantly reduced. Furthermore, for slow response trials the phase-locked gamma oscillations were significantly delayed with respect to fast response trials. Conclusion These results indicate the relevance of phase-locked gamma oscillations for very fast (not necessarily detailed) integration processes. PMID:17439642

A Jungle in There: Bacteria in Belly Buttons are Highly Diverse, but Predictable

PubMed Central

Hulcr, Jiri; Latimer, Andrew M.; Henley, Jessica B.; Rountree, Nina R.; Fierer, Noah; Lucky, Andrea; Lowman, Margaret D.; Dunn, Robert R.

2012-01-01

The belly button is one of the habitats closest to us, and yet it remains relatively unexplored. We analyzed bacteria and arachaea from the belly buttons of humans from two different populations sampled within a nation-wide citizen science project. We examined bacterial and archaeal phylotypes present and their diversity using multiplex pyrosequencing of 16S rDNA libraries. We then tested the oligarchy hypothesis borrowed from tropical macroecology, namely that the frequency of phylotypes in one sample of humans predicts its frequency in another independent sample. We also tested the predictions that frequent phylotypes (the oligarchs) tend to be common when present, and tend to be more phylogenetically clustered than rare phylotypes. Once rarefied to four hundred reads per sample, bacterial communities from belly buttons proved to be at least as diverse as communities known from other skin studies (on average 67 bacterial phylotypes per belly button). However, the belly button communities were strongly dominated by a few taxa: only 6 phylotypes occurred on >80% humans. While these frequent bacterial phylotypes (the archaea were all rare) are a tiny part of the total diversity of bacteria in human navels (<0.3% of phylotypes), they constitute a major portion of individual reads (∼1/3), and are predictable among independent samples of humans, in terms of both the occurrence and evolutionary relatedness (more closely related than randomly drawn equal sets of phylotypes). Thus, the hypothesis that “oligarchs” dominate diverse assemblages appears to be supported by human-associated bacteria. Although it remains difficult to predict which species of bacteria might be found on a particular human, predicting which species are most frequent (or rare) seems more straightforward, at least for those species living in belly buttons. PMID:23144827

Response-Related Potentials during Semantic Priming: The Effect of a Speeded Button Response Task on ERPs

PubMed Central

van Vliet, Marijn; Manyakov, Nikolay V.; Storms, Gert; Fias, Wim; Wiersema, Jan R.; Van Hulle, Marc M.

2014-01-01

This study examines the influence of a button response task on the event-related potential (ERP) in a semantic priming experiment. Of particular interest is the N400 component. In many semantic priming studies, subjects are asked to respond to a stimulus as fast and accurately as possible by pressing a button. Response time (RT) is recorded in parallel with an electroencephalogram (EEG) for ERP analysis. In this case, the response occurs in the time window used for ERP analysis and response-related components may overlap with stimulus-locked ones such as the N400. This has led to a recommendation against such a design, although the issue has not been explored in depth. Since studies keep being published that disregard this issue, a more detailed examination of influence of response-related potentials on the ERP is needed. Two experiments were performed in which subjects pressed one of two buttons with their dominant hand in response to word-pairs with varying association strength (AS), indicating a personal judgement of association between the two words. In the first experiment, subjects were instructed to respond as fast and accurately as possible. In the second experiment, subjects delayed their button response to enforce a one second interval between the onset of the target word and the button response. Results show that in the first experiment a P3 component and motor-related potentials (MRPs) overlap with the N400 component, which can cause a misinterpretation of the latter. In order to study the N400 component, the button response should be delayed to avoid contamination of the ERP with response-related components. PMID:24516556

Comparative assessment of button cells using a normalized index for potential pollution by heavy metals.

PubMed

Moreno-Merino, Luis; Jiménez-Hernández, Maria Emilia; de la Losa, Almudena; Huerta-Muñoz, Virginia

2015-09-01

Many household batteries worldwide still end up in landfills or are incinerated due to inefficient collection and recycling schemes. Toxic heavy metals from improperly discarded button cells pose a serious risk to human health and the environment, as they can pollute air, soil and water. This paper analyses a series of button cells selected from batteries available on the retail market, and compares their polluting potential. A total of 64 batteries were subjected to chemical analyses of 19 elements - including metals and metalloids - , and energy density measurements. The samples were from four different brands of each of the four most common button cell technologies (alkaline, zinc-air, silver oxide and lithium). An energy-normalized index - the Weighted Potential Pollution Index (WPPI) - was proposed to compare the polluting potential of the different batteries. The higher the battery WPPI score, the greater the content in toxic elements and the lower the energy output. The results of the chemical composition and energy density varied depending on the construction technology of the button cells. However, significant differences in both variables were also found when comparing different brands within the same technology. The differences in WPPI values confirmed the existence of a significant margin to reduce the environmental impact of discarded button cells simply by avoiding the most polluting options. The choice of the battery with the most favourable WPPI produced a reduction in potential pollution of 3-53% for silver oxide batteries, 4-39% for alkaline, 20-28% for zinc-air and 12-26% for lithium. Comparative potential pollution could be assessed when selecting batteries using an energy-normalized index such as WPPI to reduce the environmental impact of improperly disposed button cells. Published by Elsevier B.V.

Exploring Virtual Worlds with Head-Mounted Displays

DTIC Science & Technology

1989-02-01

docking problem is important both to biochemists attempting to understand how proteins and nucleic acids work, and to chemists doing analytic drug design...then depressing the mouse button he is able to manipulate the methotrexate. A. long as the mouse button is depressed the methotrexate will follow the... depressing the mouse button outside of the drug’s "grabbing" volume. In this mode, both molecules move in concert. When the active site is positioned to

The floor effect: impoverished spatial memory for elevator buttons.

PubMed

Vendetti, Michael; Castel, Alan D; Holyoak, Keith J

2013-05-01

People typically remember objects to which they have frequently been exposed, suggesting that memory is a by-product of perception. However, prior research has shown that people have exceptionally poor memory for the features of some objects (e.g., coins) to which they have been exposed over the course of many years. Here, we examined how people remember the spatial layout of the buttons on a frequently used elevator panel, to determine whether physical interaction (rather than simple exposure) would ensure the incidental encoding of spatial information. Participants who worked in an eight-story office building displayed very poor recall for the elevator panel but above-chance performance on a recognition test. Performance was related to how often and how recently the person had used the elevator. In contrast to their poor memory for the spatial layout of the elevator buttons, most people readily recalled small distinctive graffiti on the elevator walls. In a more implicit test, the majority were able to locate their office floor and the eighth floor button when asked to point toward these buttons when in the actual elevator, with the button labels covered. However, identification was very poor for other floors (including the first floor), suggesting that even frequent interaction with information does not always lead to accurate spatial memory. These findings have implications for understanding the complex relationships among attention, expertise, and memory.

Identifying predictive factors for long-term complications following button battery impactions: A case series and literature review.

PubMed

Eliason, Michael J; Melzer, Jonathan M; Winters, Jessica R; Gallagher, Thomas Q

2016-08-01

To complement a case series review of button battery impactions managed at our single military tertiary care center with a thorough literature review of laboratory research and clinical cases to develop a protocol to optimize patient care. Specifically, to identify predictive factors of long-term complications which can be used by the pediatric otolaryngologist to guide patient management after button battery impactions. A retrospective review of the Department of Defense's electronic medical record systems was conducted to identify patients with button battery ingestions and then characterize their treatment course. A thorough literature review complemented the lessons learned to identify potentially predictive clinical measures for long-term complications. Eight patients were identified as being treated for button battery impaction in the aerodigestive tract with two sustaining long-term complications. The median age of the patients treated was 33 months old and the median estimated time of impaction in the aerodigestive tract prior to removal was 10.5 h. Time of impaction, anatomic direction of the battery's negative pole, and identifying specific battery parameters were identified as factors that may be employed to predict sequelae. Based on case reviews, advancements in battery manufacturing, and laboratory research, there are distinct clinical factors that should be assessed at the time of initial therapy to guide follow-up management to minimize potential catastrophic sequelae of button battery ingestion. Published by Elsevier Ireland Ltd.

Drying kinetics and characteristics of combined infrared-vacuum drying of button mushroom slices

NASA Astrophysics Data System (ADS)

Salehi, Fakhreddin; Kashaninejad, Mahdi; Jafarianlari, Ali

2017-05-01

Infrared-vacuum drying characteristics of button mushroom ( Agaricus bisporus) were evaluated in a combined dryer system. The effects of drying parameters, including infrared radiation power (150-375 W), system pressure (5-15 kPa) and time (0-160 min) on the drying kinetics and characteristics of button mushroom slices were investigated. Both the infrared lamp power and vacuum pressure influenced the drying time of button mushroom slices. The rate constants of the nine different kinetic's models for thin layer drying were established by nonlinear regression analysis of the experimental data which were found to be affected mainly by the infrared power level while system pressure had a little effect on the moisture ratios. The regression results showed that the Page model satisfactorily described the drying behavior of button mushroom slices with highest R value and lowest SE values. The effective moisture diffusivity increases as power increases and range between 0.83 and 2.33 × 10-9 m2/s. The rise in infrared power has a negative effect on the ΔE and with increasing in infrared radiation power it was increased.

Numerical analysis of the beam position monitor pickup for the Iranian light source facility

NASA Astrophysics Data System (ADS)

Shafiee, M.; Feghhi, S. A. H.; Rahighi, J.

2017-03-01

In this paper, we describe the design of a button type Beam Position Monitor (BPM) for the low emittance storage ring of the Iranian Light Source Facility (ILSF). First, we calculate sensitivities, induced power and intrinsic resolution based on solving Laplace equation numerically by finite element method (FEM), in order to find the potential at each point of BPM's electrode surface. After the optimization of the designed BPM, trapped high order modes (HOM), wakefield and thermal loss effects are calculated. Finally, after fabrication of BPM, it is experimentally tested by using a test-stand. The results depict that the designed BPM has a linear response in the area of 2×4 mm2 inside the beam pipe and the sensitivity of 0.080 and 0.087 mm-1 in horizontal and vertical directions. Experimental results also depict that they are in a good agreement with numerical analysis.

Improved design and in-situ measurements of new beam position monitors for Indus-2

NASA Astrophysics Data System (ADS)

Kumar, M.; Babbar, L. K.; Holikatti, A. C.; Yadav, S.; Tyagi, Y.; Puntambekar, T. A.; Senecha, V. K.

2018-01-01

Beam position monitors (BPM) are important diagnostic devices used in particle accelerators to monitor position of the beam for various applications. Improved version of button electrode BPM has been designed using CST Studio Suite for Indus-2 ring. The new BPMs are designed to replace old BPMs which were designed and installed more than 12 years back. The improved BPMs have higher transfer impedance, resonance free output signal, equal sensitivity in horizontal and vertical planes and fast decaying wakefield as compared to old BPMs. The new BPMs have been calibrated using coaxial wire method. Measurement of transfer impedance and time domain signals has also been performed in-situ with electron beam during Indus-2 operation. The calibration and beam based measurements results showed close agreement with the design parameters. This paper presents design, electromagnetic simulations, calibration result and in-situ beam based measurements of newly designed BPMs.

Button batteries

MedlinePlus

Swallowing batteries ... These devices use button batteries: Calculators Cameras Hearing aids Penlights Watches ... If a person puts the battery up their nose and breathes it further in, ... problems Cough Pneumonia (if the battery goes unnoticed) ...

Poisoning: First Aid

MedlinePlus

... Plants Foreign bodies such as watch or button batteries How you treat someone who may have been ... have applied medicated patches or swallowed a button battery. Call 911 or your local emergency number immediately ...

Vascular ring complicates accidental button battery ingestion.

PubMed

Mercer, Ronald W; Schwartz, Matthew C; Stephany, Joshua; Donnelly, Lane F; Franciosi, James P; Epelman, Monica

2015-01-01

Button battery ingestion can lead to dangerous complications, including vasculoesophageal fistula formation. The presence of a vascular ring may complicate battery ingestion if the battery lodges at the level of the ring and its important vascular structures. We report a 4-year-old boy with trisomy 21 who was diagnosed with a vascular ring at the time of button battery ingestion and died 9 days after presentation due to massive upper gastrointestinal bleeding from esophageal erosion and vasculoesophageal fistula formation. Copyright © 2015 Elsevier Inc. All rights reserved.

Graphical User Interface for a Remote Medical Monitoring System: U.S. Army Medic Recommendations

DTIC Science & Technology

2009-11-01

screens. The majority of medics (70%) also wanted a name lis! screen that, when tapped , would go to an individual patient screen. In the name list...button has been pushed. Tapping on thaI button would prompt the user to enter the password. Tapping on the light button would illuminate the screen...a summary of current local weather conditions would be dis- played in the lower ! eft of the screen. In the lower right of this map screen is

High current capacity electrical connector

DOEpatents

Bettis, Edward S.; Watts, Harry L.

1976-01-13

An electrical connector is provided for coupling high current capacity electrical conductors such as copper busses or the like. The connector is arranged in a "sandwiched" configuration in which a conductor plate contacts the busses along major surfaces thereof clamped between two stainless steel backing plates. The conductor plate is provided with a plurality of contact buttons affixed therein in a spaced array such that the caps of the buttons extend above the conductor plate surface to contact the busses. When clamping bolts provided through openings in the sandwiched arrangement are tightened, Belleville springs provided under the rim of each button cap are compressed and resiliently force the caps into contact with the busses' contacting surfaces to maintain a predetermined electrical contact area provided by the button cap tops. The contact area does not change with changing thermal or mechanical stresses applied to the coupled conductors.

Button fixation technique for Achilles tendon reinsertion: a biomechanical study.

PubMed

Awogni, David; Chauvette, Guillaume; Lemieux, Marie-Line; Balg, Frédéric; Langelier, Ève; Allard, Jean-Pascal

2014-01-01

Chronic insertional tendinopathy of the Achilles tendon is a frequent and disabling pathologic entity. Operative treatment is indicated for patients for whom nonoperative management has failed. The treatment can consist of the complete detachment of the tendon insertion and extensive debridement. We biomechanically tested a new operative technique that uses buttons for fixation of the Achilles tendon insertion on the posterior calcaneal tuberosity and compared it with 2 standard bone anchor techniques. A total of 40 fresh-frozen cadaver specimens were used to compare 3 fixation techniques for reinserting the Achilles tendon: single row anchors, double row anchors, and buttons. The ultimate loads and failure mechanisms were recorded. The button assembly (median load 764 N, range 713 to 888) yielded a median fixation strength equal to 202% (range 137% to 251%) of that obtained with the double row anchors (median load 412 N, range 301 to 571) and 255% (range 213% to 317%) of that obtained with the single row anchors (median load 338 N, range 241 to 433N). The most common failure mechanisms were suture breakage with the buttons (55%) and pull out of the implant with the double row (70%) and single row (85%) anchors. The results of the present biomechanical cadaver study have shown that Achilles tendon reinsertion fixation using the button technique provides superior pull out strength than the bone anchors tested. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Novel method to avoid the open-sky condition in penetrating keratoplasty: covered cornea technique.

PubMed

Arslan, Osman S; Unal, Mustafa; Arici, Ceyhun; Cicik, Erdoğan; Mangan, Serhat; Atalay, Eray

2014-09-01

The aim of this study was to present a novel technique to avoid the open-sky condition in pediatric and adult penetrating keratoplasty (PK). Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. After trephining the recipient cornea up to a depth of 50% to 70%, the anterior chamber was entered at 1 point. Then, only a 2 clock hour segment of the recipient button was incised, and this segment was sutured to the recipient rim with a single tight suture. The procedure was repeated until the entire recipient button was excised and resutured. The donor corneal button was sutured to the recipient corneal rim. The sutures between the recipient button and the rim were then cut off, and the recipient button was drawn out. None of the patients operated on with this technique developed complications related to the open-sky condition. Visual acuities, graft failure rates, and endothelial cell loss were comparable with the findings of studies performed for conventional PK. The technique described avoids the open-sky condition during the entire PK procedure. Endothelial cell loss rates are acceptable.

Surgical treatment of pectoralis major muscle rupture with adjustable cortical button.

PubMed

Pochini, Alberto de Castro; Rodrigues, Marcus de Souza Barbosa; Yamashita, Larissa; Belangero, Paulo Santoro; Andreoli, Carlos Vicente; Ejnisman, Benno

2018-01-01

To assess the tendon reconstruction technique for total rupture of the pectoralis major muscle using an adjustable cortical button. Prospective study of 27 male patients with a mean age of 29.9 (SD = 5.3 years) and follow-up of 2.3 years. The procedure consisted of autologous grafts taken from the semitendinosus and gracilis tendons and an adjustable cortical button. Patients were evaluated functionally by the Bak criteria. The surgical treatment of pectoralis major muscle tendon reconstruction was performed in the early stages (three weeks) in six patients (22.2%) and in 21 patients (77.8%), in the late stages. Patients operated with the adjustable cortical button technique obtained 96.3% excellent or good results, with only 3.7% having poor results (Bak criteria). Of the total, 85.2% were injured while performing bench press exercises and 14.8%, during the practice of Brazilian jiu-jitsu or wrestling. All weight-lifting athletes had history of anabolic steroid use. The early or delayed reconstruction of ruptured pectoralis major muscle tendons with considerable muscle retraction, using an adjustable cortical button and autologous knee flexor grafts, showed a high rate of good results.

[Autoshaping of a button-push response and eye movement in human subjects].

PubMed

Kimura, H; Fukui, I; Inaki, K

1990-12-01

Two experiments were conducted with human subjects to investigate the similarities and differences between animal and human behaviors under autoshaping procedures. In these experiments, light served as CS, and display on TV served as US. Whether the pushing button response or gazing response to CS could be obtained in human subjects under Pavlovian conditioning procedure was examined. In Experiment 1, uninstructed naive subjects were placed in a room containing a push-button and a TV display. Within the experimental sessions, the push-button was lit for 8 s as CS, and then paired with the display of a soft pornographic program on TV for 10 s. The result indicated that the modeling of pushing button promoted the increase of response probability among the subjects. The trials conducted after the rest period indicated an increase of response probability. In Experiment 2, a 4 cm square translucent panel was lit for 20 s as CS, and then paired with the display of a computer graphic picture on TV for 8 s as US. Some subjects started gazing at the CS for several seconds. These results indicated that some subjects could acquire the gazing response under the autoshaping procedure.

Dissipative dark soliton in a complex plasma.

PubMed

Heidemann, R; Zhdanov, S; Sütterlin, R; Thomas, H M; Morfill, G E

2009-04-03

The observation of a dark soliton in a three-dimensional complex plasma containing monodisperse microparticles is presented. We perform our experiments using neon gas in the bulk plasma of an rf discharge. A gas temperature gradient of 500K/m is applied to balance gravity and to levitate the particles in the bulk plasma. The wave is excited by a short voltage pulse on the electrodes of the radio frequency discharge chamber. It is found that the wave propagates with constant speed. The propagation time of the dark soliton is approximately 20 times longer than the damping time.

An Experimental Study of the Ionization of Low-Density Gas Flows by Induced Discharges

NASA Technical Reports Server (NTRS)

Barger, R. L.; Brooks, J. D.; Beasley, W. D.

1960-01-01

Induced discharges are advantageous for ionizing low-density flows in that they introduce no electrode contamination into the flow and they provide a relatively high degree of ionization with good coupling of power into the gas. In this investigation a 40-megacycle oscillator was used to produce and maintain induced discharges in argon and mercury-vapor flows. Methods for preventing blowout of the discharge were determined, and power measurements were made with an in-line wattmeter. Some results with damped oscillations pulsed at 1,000 pulses per second are also presented.

Dissipative Dark Soliton in a Complex Plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heidemann, R.; Zhdanov, S.; Suetterlin, R.

2009-04-03

The observation of a dark soliton in a three-dimensional complex plasma containing monodisperse microparticles is presented. We perform our experiments using neon gas in the bulk plasma of an rf discharge. A gas temperature gradient of 500K/m is applied to balance gravity and to levitate the particles in the bulk plasma. The wave is excited by a short voltage pulse on the electrodes of the radio frequency discharge chamber. It is found that the wave propagates with constant speed. The propagation time of the dark soliton is approximately 20 times longer than the damping time.

Soft robot design methodology for `push-button' manufacturing

NASA Astrophysics Data System (ADS)

Paik, Jamie

2018-06-01

`Push-button' or fully automated manufacturing would enable the production of robots with zero intervention from human hands. Realizing this utopia requires a fundamental shift from a sequential (design-materials-manufacturing) to a concurrent design methodology.

MedlinePlus FAQ: Disease or Condition Information

MedlinePlus

... on the Health Topics button on the MedlinePlus homepage. You can also find the Health Topics button ... MedlinePlus Connect for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 ...

Development of non-keyboard input device checklists through assessments.

PubMed

Woods, Valerie; Hastings, Sarah; Buckle, Peter; Haslam, Roger

2003-11-01

An assessment of non-keyboard input devices (NKID) was conducted to identify factors for good design in relation to operation, performance and comfort. Twenty-seven NKID users, working in health and safety, evaluated eight devices that included mice, trackballs and a joystick mouse. The factors considered important for good design were: (1) comfortable hand and finger position, (2) adequate control, (3) intuitive and easy to use, (4) ease of device, button and trackball movement, (5) good interaction with software, (6) provision of suitable accessories. Mice were rated more favourably than trackballs or the joystick mouse. The design of the standard 2-button mouse (D4) was considered most desirable to use; the 3-button mouse (D1) and 3-button curved mouse (D8) were also favoured. Assessment data and comments were drawn together with previously published research to produce useful tools for NKID purchasing (i.e. Device Purchasing Checklist) and assessment (i.e. Device Assessment Checklist).

Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat.

PubMed

Goodman, Alice E; Carmichael, Daniel T

2016-03-01

Maxillofacial trauma in cats often results in mandibular symphyseal separation in addition to injuries of the caudal mandible and/or temporomandibular joint (TMJ). Caudal mandibular and TMJ injuries are difficult to access and stabilize using direct fixation techniques, thus indirect fixation is commonly employed. The immediate goals of fixation include stabilization for return to normal occlusion and function with the long-term objective of bony union. Indirect fixation techniques commonly used for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation (MMF) with acrylic composite, interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. This article introduces a modification of the previously described "labial reverse suture through buttons" technique used by Koestlin et al and the "labial locking with buttons" technique by Rocha et al. In cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. The construct can remain in place for a variable of amount of time, depending on its intended purpose. It serves as an alternative to the tape muzzle, which is rarely tolerated by cats. This technique can be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. The purpose of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/TMJ luxations in a step-by-step fashion.

Effects of contamination by either blood or a hemostatic agent on the shear bond strength of orthodontic buttons

PubMed Central

Alkis, Huseyin; Turkkahraman, Hakan

2013-01-01

Objective To evaluate the effects of contamination by either blood or a hemostatic agent on the shear bond strength (SBS) of orthodontic buttons. Methods We used 45 freshly extracted, non-carious, impacted third molars that were divided into 3 groups of 15. Each tooth was etched with 37% phosphoric acid gel for 30 s. Human blood or the blood stopper agent was applied to the tooth surface in groups I and II, respectively. Group III teeth were untreated (controls). Orthodontic buttons were bonded to the teeth using light-curing composite resin. After bonding, the SBS of the button was determined using a Universal testing machine. Any adhesive remaining after debonding was assessed and scored according to the modified adhesive remnant index (ARI). ANOVA with post-hoc Tukey's test was used to determine significant differences in SBS and Fisher's exact test, to determine significant differences in ARI scores among groups. Results ANOVA indicated a significant difference between groups (p < 0.001). The highest SBS values were measured in group III (10.73 ± 0.96 MPa). The SBS values for teeth in groups I and II were significantly lower than that of group III (p < 0.001). The lowest SBS values were observed in group I teeth (4.17 ± 1.11 MPa) (p < 0.001). Conclusions Contamination of tooth surfaces with either blood or hemostatic agent significantly decreased the SBS of orthodontic buttons. When the contamination risk is high, it is recommended to use the blood stopper agent when bonding orthodontic buttons on impacted teeth. PMID:23671834

Smoke alarm tests may not adequately indicate smoke alarm function.

PubMed

Peek-Asa, Corinne; Yang, Jingzhen; Hamann, Cara; Young, Tracy

2011-01-01

Smoke alarms are one of the most promoted prevention strategies to reduce residential fire deaths, and they can reduce residential fire deaths by half. Smoke alarm function can be measured by two tests: the smoke alarm button test and the chemical smoke test. Using results from a randomized trial of smoke alarms, we compared smoke alarm response to the button test and the smoke test. The smoke alarms found in the study homes at baseline were tested, as well as study alarms placed into homes as part of the randomized trial. Study alarms were tested at 12 and 42 months postinstallation. The proportion of alarms that passed the button test but not the smoke test ranged from 0.5 to 5.8% of alarms; this result was found most frequently among ionization alarms with zinc or alkaline batteries. These alarms would indicate to the owner (through the button test) that the smoke alarm was working, but the alarm would not actually respond in the case of a fire (as demonstrated by failing the smoke test). The proportion of alarms that passed the smoke test but not the button test ranged from 1.0 to 3.0%. These alarms would appear nonfunctional to the owner (because the button test failed), even though the alarm would operate in response to a fire (as demonstrated by passing the smoke test). The general public is not aware of the potential for inaccuracy in smoke alarm tests, and burn professionals can advocate for enhanced testing methods. The optimal test to determine smoke alarm function is the chemical smoke test.

The validity, reliability, and utility of the iButton® for measurement of body temperature circadian rhythms in sleep/wake research.

PubMed

Hasselberg, Michael J; McMahon, James; Parker, Kathy

2013-01-01

Changes in core body temperature due to heat transfer through the skin have a major influence on sleep regulation. Traditional measures of skin temperature are often complicated by extensive wiring and are not practical for use in normal living conditions. This review describes studies examining the reliability, validity and utility of the iButton®, a wireless peripheral thermometry device, in sleep/wake research. A review was conducted of English language literature on the iButton as a measure of circadian body temperature rhythms associated with the sleep/wake cycle. Seven studies of the iButtton as a measure of human body temperature were included. The iButton was found to be a reliable and valid measure of body temperature. Its application to human skin was shown to be comfortable and tolerable with no significant adverse reactions. Distal skin temperatures were negatively correlated with sleep/wake activity, and the temperature gradient between the distal and proximal skin (DPG) was identified as an accurate physiological correlate of sleep propensity. Methodological issues included site of data logger placement, temperature masking factors, and temperature data analysis. The iButton is an inexpensive, wireless data logger that can be used to obtain a valid measurement of human skin temperature. It is a practical alternative to traditional measures of circadian rhythms in sleep/wake research. Further research is needed to determine the utility of the iButton in vulnerable populations, including those with neurodegenerative disorders and memory impairment and pediatric populations. Copyright © 2011 Elsevier B.V. All rights reserved.

78 FR 27995 - Notice of Inventory Completion for Native American Human Remains and Associated Funerary Objects...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-13

... fragments, 29 historic ceramic sherds, 1 prehistoric ceramic sherd, 128 unmodified faunal bone fragments, 1 modified deer rib, 3 bone buttons, 4 chipped stone flakes, 2 wooden buttons, 1 historic clay pipe bowl...

Comparison of numeric keyboard and CRT line-labeled buttons for information access. [in computerized, area navigation system for aircraft

NASA Technical Reports Server (NTRS)

Williams, D.

1976-01-01

Test were conducted to determine whether differences in speed and accuracy are experienced when using either line-labeled index buttons or a numeric keyboard for page selection in airborne CRT-display area navigation systems. The experiment was conducted with six airline pilots, each flying the same two simulated RNAV routes. Three pilot subjects used line-labeled buttons adjacent to the CRT screen, while three used a numeric keyboard for page access. The hypothesis of no differences in response times between the two modes of access could not be rejected.

Button battery ingestion: the Greek experience and review of the literature.

PubMed

Amanatidou, Virginia; Sofidiotou, Vassiliki; Fountas, Kostas; Kalostou, Angeliki; Tsamadou, Athina; Papathanassiou, Vassiliki; Neou, Polyxeni

2011-03-01

Foreign body ingestion is a common cause of admission in the pediatric emergency room. In the past, button batteries accounted for less than 2% of the foreign bodies ingested by small children, but in the last 2 decades, they show a rapidly increased frequency. The aim of the present study was to evaluate the potential risk after button battery ingestion in relation with the clinical manifestations and to perform a treatment-observation protocol in accordance with the international procedure. In a prospective observational analysis from November 2007 through February 2008, 31 cases of button battery ingestion were recorded by the Greek Poison Information Center. The interval between the accidental ingestion and first medical contact ranged from 5 minutes to 10 days. After initial evaluation including clinical examination and radiological localization of the foreign body, all cases were treated as outpatients. Reported complications included "black stools" in 9% and diarrhea in 3% of cases. In 1 case, the battery was endoscopically removed. The role of primary care physicians in informing the public about the potential danger of button battery digestion is crucial. Pediatricians should educate the parents about this hazard, as part of the routine guidelines for childproofing at home. Once again, prolepsis is the best policy.

Experimental observation of standing wave effect in low-pressure very-high-frequency capacitive discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yong-Xin; Gao, Fei; Liu, Jia

2014-07-28

Radial uniformity measurements of plasma density were carried out by using a floating double probe in a cylindrical (21 cm in electrode diameter) capacitive discharge reactor driven over a wide range of frequencies (27–220 MHz). At low rf power, a multiple-node structure of standing wave effect was observed at 130 MHz. The secondary density peak caused by the standing wave effect became pronounced and shifts toward the axis as the driving frequency further to increase, indicative of a much more shortened standing-wave wavelength. With increasing rf power, the secondary density peak shift toward the radial edge, namely, the standing-wave wavelength was increased,more » in good qualitative agreement with the previous theory and simulation results. At higher pressures and high frequencies, the rf power was primarily deposited at the periphery of the electrode, due to the fact that the waves were strongly damped as they propagated from the discharge edge into the center.« less

Energy harvesting with stacked dielectric elastomer transducers: Nonlinear theory, optimization, and linearized scaling law

NASA Astrophysics Data System (ADS)

Tutcuoglu, A.; Majidi, C.

2014-12-01

Using principles of damped harmonic oscillation with continuous media, we examine electrostatic energy harvesting with a "soft-matter" array of dielectric elastomer (DE) transducers. The array is composed of infinitely thin and deformable electrodes separated by layers of insulating elastomer. During vibration, it deforms longitudinally, resulting in a change in the capacitance and electrical enthalpy of the charged electrodes. Depending on the phase of electrostatic loading, the DE array can function as either an actuator that amplifies small vibrations or a generator that converts these external excitations into electrical power. Both cases are addressed with a comprehensive theory that accounts for the influence of viscoelasticity, dielectric breakdown, and electromechanical coupling induced by Maxwell stress. In the case of a linearized Kelvin-Voigt model of the dielectric, we obtain a closed-form estimate for the electrical power output and a scaling law for DE generator design. For the complete nonlinear model, we obtain the optimal electrostatic voltage input for maximum electrical power output.

Disposable Electronic Cigarettes and Electronic Hookahs: Evaluation of Performance

PubMed Central

Williams, Monique; Ghai, Sanjay

2015-01-01

Introduction: The purpose of this study was to characterize the performance of disposable button-activated and disposable airflow-activated electronic cigarettes (EC) and electronic hookahs (EH). Methods: The airflow rate required to produce aerosol, pressure drop, and the aerosol absorbance at 420nm were measured during smoke-outs of 9 disposable products. Three units of each product were tested in these experiments. Results: The airflow rates required to produce aerosol and the aerosol absorbances were lower for button-activated models (3mL/s; 0.41–0.55 absorbance) than for airflow-activated models (7–17mL/s; 0.48–0.84 absorbance). Pressure drop was also lower across button-activated products (range = 6–12mm H2O) than airflow-activated products (range = 15–67mm H20). For 25 of 27 units tested, airflow did not have to be increased during smoke-out to maintain aerosol production, unlike earlier generation models. Two brands had uniform performance characteristics for all parameters, while 3 had at least 1 product that did not function normally. While button-activated models lasted 200 puffs or less and EH airflow-activated models often lasted 400 puffs, none of the models produced as many puffs as advertised. Puff number was limited by battery life, which was shorter in button-activated models. Conclusion: The performance of disposable products was differentiated mainly by the way the aerosol was produced (button vs airflow-activated) rather than by product type (EC vs EH). Users needed to take harder drags on airflow-activated models. Performance varied within models, and battery life limited the number of puffs. Data suggest quality control in manufacturing varies among brands. PMID:25104117

Insertion of Balloon Retained Gastrostomy Buttons: A 5-Year Retrospective Review of 260 Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Power, Sarah, E-mail: sarahpower28@yahoo.co.uk; Kavanagh, Liam N.; Shields, Mary C.

Radiologically inserted gastrostomy (RIG) is an established way of maintaining enteral nutrition in patients who cannot maintain nutrition orally. The purpose of this study was to evaluate the safety and efficacy of primary placement of a wide bore button gastrostomy in a large, varied patient population through retrospective review. All patients who underwent gastrostomy placement from January 1, 2004 to January 1, 2009 were identified. 18-Fr gastrostomy buttons (MIC-Key G) were inserted in the majority. Follow-up ranged from 6 months to 4.5 years. A total of 260 patients (M:F 140:120, average age 59.2 years) underwent gastrostomy during the study period.more » Overall success rate for RIG placement was 99.6 %, with success rate of 95.3 % for primary button insertion. Indications included neurological disorders (70 %), esophageal/head and neck malignancy (21 %), and other indications (9 %). Major and minor complication rates were 1.2 and 12.8 %, respectively. Thirty-day mortality rate was 6.8 %. One third of patients underwent gastrostomy reinsertion during the study period, the main indication for which was inadvertent catheter removal. Patency rate was high at 99.5 %. The maximum number of procedures in any patient was 8 (n = 2), and the average tube dwell time was 125 days. Primary radiological insertion of a wide bore button gastrostomy is a safe technique, with high success rate, high patency rate, and low major complication rate. We believe that it is feasible to attempt button gastrostomy placement in all patients, once tract length is within limits of tube length. If difficulty is encountered, then a standard tube may simply be placed instead.« less

The joint Simon effect depends on perceived agency, but not intentionality, of the alternative action

PubMed Central

Stenzel, Anna; Dolk, Thomas; Colzato, Lorenza S.; Sellaro, Roberta; Hommel, Bernhard; Liepelt, Roman

2014-01-01

A co-actor's intentionality has been suggested to be a key modulating factor for joint action effects like the joint Simon effect (JSE). However, in previous studies intentionality has often been confounded with agency defined as perceiving the initiator of an action as being the causal source of the action. The aim of the present study was to disentangle the role of agency and intentionality as modulating factors of the JSE. In Experiment 1, participants performed a joint go/nogo Simon task next to a co-actor who either intentionally controlled a response button with own finger movements (agency+/intentionality+) or who passively placed the hand on a response button that moved up and down on its own as triggered by computer signals (agency−/intentionality−). In Experiment 2, we included a condition in which participants believed that the co-actor intentionally controlled the response button with a Brain-Computer Interface (BCI) while placing the response finger clearly besides the response button, so that the causal relationship between agent and action effect was perceptually disrupted (agency−/intentionality+). As a control condition, the response button was computer controlled while the co-actor placed the response finger besides the response button (agency−/intentionality−). Experiment 1 showed that the JSE is present with an intentional co-actor and causality between co-actor and action effect, but absent with an unintentional co-actor and a lack of causality between co-actor and action effect. Experiment 2 showed that the JSE is absent with an intentional co-actor, but no causality between co-actor and action effect. Our findings indicate an important role of the co-actor's agency for the JSE. They also suggest that the attribution of agency has a strong perceptual basis. PMID:25140144

The joint Simon effect depends on perceived agency, but not intentionality, of the alternative action.

PubMed

Stenzel, Anna; Dolk, Thomas; Colzato, Lorenza S; Sellaro, Roberta; Hommel, Bernhard; Liepelt, Roman

2014-01-01

A co-actor's intentionality has been suggested to be a key modulating factor for joint action effects like the joint Simon effect (JSE). However, in previous studies intentionality has often been confounded with agency defined as perceiving the initiator of an action as being the causal source of the action. The aim of the present study was to disentangle the role of agency and intentionality as modulating factors of the JSE. In Experiment 1, participants performed a joint go/nogo Simon task next to a co-actor who either intentionally controlled a response button with own finger movements (agency+/intentionality+) or who passively placed the hand on a response button that moved up and down on its own as triggered by computer signals (agency-/intentionality-). In Experiment 2, we included a condition in which participants believed that the co-actor intentionally controlled the response button with a Brain-Computer Interface (BCI) while placing the response finger clearly besides the response button, so that the causal relationship between agent and action effect was perceptually disrupted (agency-/intentionality+). As a control condition, the response button was computer controlled while the co-actor placed the response finger besides the response button (agency-/intentionality-). Experiment 1 showed that the JSE is present with an intentional co-actor and causality between co-actor and action effect, but absent with an unintentional co-actor and a lack of causality between co-actor and action effect. Experiment 2 showed that the JSE is absent with an intentional co-actor, but no causality between co-actor and action effect. Our findings indicate an important role of the co-actor's agency for the JSE. They also suggest that the attribution of agency has a strong perceptual basis.

Tunnel magnetoresistance in ultrathin L10 MnGa/MgO perpendicular magnetic tunnel junctions

NASA Astrophysics Data System (ADS)

Suzuki, K. Z.; Miura, Y.; Ranjbar, R.; Sugihara, A.; Mizukami, S.

2018-06-01

L10 MnGa is one of the interesting magnetic alloys for spin-transfer-torque based applications because such alloys have high perpendicular magnetic anisotropy, small magnetization, and low Gilbert damping. Magnetic tunnel junctions (MTJs) with ultrathin MnGa electrodes have recently been demonstrated using the room temperature growth technique of MnGa on paramagnetic B2-ordered CoGa templates, which exhibited a small TMR ratio of  ∼3%. To obtain a higher TMR ratio, we systematically investigated the annealing dependence of the TMR ratio with MTJs with 1–5 nm thick MnGa electrodes in this study. The TMR ratios were 2%–3% without annealing, which were the same as those reported previously, and the TMR ratios reached their maximum values of 6%–8% at an annealing temperature of approximately 250 °C for the MTJs with 2–5 nm MnGa electrodes. The TMR ratio increased to approximately 25% at 10 K for those MTJs. These TMR ratios were slightly higher than those reported in MTJs with 30 nm-thick MnGa electrodes. The annealing temperature at which TMR showed the maximum value tended to decrease with decreasing MnGa thickness, and this low annealing endurance may be attributed to the atomic mixing between MnGa and barrier/buffer layers. The TMR ratio was discussed in terms of both coherent tunneling based on first principles calculations with different element terminations at the interface and incoherent tunneling.

Method Development for the Determination of Free and Esterified Sterols in Button Mushrooms (Agaricus bisporus).

PubMed

Hammann, Simon; Vetter, Walter

2016-05-04

Ergosterol is the major sterol in button mushrooms (Agaricus bisporus) and can occur as free alcohol or esterified with fatty acids (ergosteryl esters). In this study, gas chromatography with mass spectrometry in the selected ion monitoring mode (GC/MS-SIM) was used to determine ergosterol and ergosteryl esters as well as other sterols and steryl esters in button mushrooms. Different quality control measures were established and sample preparation procedures were compared to prevent the formation of artifacts and the degradation of ergosteryl esters. The final method was then used for the determination of ergosterol (443 ± 44 mg/100 g dry matter (d.m.)) and esterified ergosterol (12 ± 6 mg/100 g d.m.) in button mushroom samples (n = 4). While the free sterol fraction was vastly dominated by ergosterol (∼90% of five sterols in total), the steryl ester fraction was more diversified (nine sterols in total, ergosterol ∼55%) and consisted primarily of linoleic acid esters.

Changes in non-volatile taste components of button mushroom (Agaricus bisporus) during different stages of freeze drying and freeze drying combined with microwave vacuum drying.

PubMed

Pei, Fei; Shi, Ying; Gao, Xingyang; Wu, Fangning; Mariga, Alfred Mugambi; Yang, Wenjian; Zhao, Liyan; An, Xinxin; Xin, Zhihong; Yang, Fangmei; Hu, Qiuhui

2014-12-15

Button mushroom slices were dehydrated using freeze drying (FD) or FD combined with microwave vacuum drying (FMVD), and the non-volatile component profiles were studied. The results showed that the level of non-volatile components in button mushroom firstly increased during sublimation of FD/FMVD process and then fell during desorption in FD process and MVD in FMVD process. Compared to FD products, the contents of soluble sugars and polyols in FMVD products were relatively low, whereas the contents of total free amino acids were significantly higher, close to the level of fresh mushroom. However, there was no significant difference in the contents of 5'-nucleotides and organic acids between FD and FMVD products. The equivalent umami concentration (EUC) values for FD and FMVD products did not differ from fresh, indicating that both drying methods could effectively preserve MSG (monosodium glutamate)-like components in button mushroom. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental analysis of surface finish in normal conducting cavities

NASA Astrophysics Data System (ADS)

Zarrebini-Esfahani, A.; Aslaninejad, M.; Ristic, M.; Long, K.

2017-10-01

A normal conducting 805 MHz test cavity with an in built button shaped sample is used to conduct a series of surface treatment experiments. The button enhances the local fields and influences the likelihood of an RF breakdown event. Because of their smaller sizes, compared to the whole cavity surface, they allow practical investigations of the effects of cavity surface preparation in relation to RF breakdown. Manufacturing techniques and steps for preparing the buttons to improve the surface quality are described in detail. It was observed that even after the final stage of the surface treatment, defects on the surface of the cavities still could be found.

Key Aroma Compounds in Lippia dulcis (Dushi Button).

PubMed

Schmitt, Rainer; Cappi, Michael; Pollner, Gwendola; Greger, Veronika

2018-03-14

An aroma extract dilution analysis (AEDA) applied on aroma extracts prepared from the edible flower Dushi Button ( Lippia dulcis) resulted in the detection of 34 odor-active compounds. The highest flavor dilution (FD) factors were determined for methyl 2-methylbutanoate, ethyl 2-methylbutanoate, 4-mercapto-4-methyl-2-pentanone, an unknown caramel-like compound, and vanillin. Quantitative measurements performed by application of stable isotope dilution assays (SIDA), followed by a calculation of odor activity values (OAVs), resulted in the revelation of 4-mercapto-4-methyl-2-pentanone, linalool, myrcene, ethyl 2-methylbutanoate, methyl 2-methylbutanoate, and ( Z)-3-hexenal as important contributors to the flavor of Dushi Buttons.

Investigations of the historic textiles excavated from Ancient Ainos (Enez - Turkey) by multiple analytical techniques

NASA Astrophysics Data System (ADS)

Akyuz, Sevim; Akyuz, Tanil; Cakan, Banu; Basaran, Sait

2014-09-01

Some metal ornamented textile specimens and a textile button, excavated from Ancient Ainos (Enez - Turkey), have been investigated using FTIR and EDXRF spectrometry, for the purpose of material identification. FTIR spectral results indicated that textiles were made from partially degummed Bombyx mori silk. The IR spectral investigation of the textile button revealed that some cellulose fillings were used inside the button. The EDXRF analysis of the metal ornaments showed that they were silver plated copper. Surface morphology of the textiles and the metal ornaments were investigated by SEM images. It was shown that textile fibers were highly degraded.

Hybrid: Braking

Science.gov Websites

Button Stopped button highlighted subbanner graphic: gray bar STOPPED When the vehicle is stopped engine when additional power is needed. It also acts as a generator, converting energy from the engine or engine instantly when needed. Main stage: See through car with battery, engine, and electric motor

Armpits, Belly Buttons and Chronic Wounds: The ABCs of Our Body Bacteria

MedlinePlus

... Wounds: The ABCs of Our Body Bacteria Inside Life Science View All Articles | Inside Life Science Home Page Armpits, Belly Buttons and Chronic Wounds: ... Other Findings About Our Resident Microbes This Inside Life Science article also appears on LiveScience . Learn about related ...

An Experimental Investigation of the Structural Dynamics of a Torsionally Soft Rotor in Vacuum.

DTIC Science & Technology

1986-07-01

attached to the blades for the present test program were of G1356 material supplied by Piezo Electric Products. They were made of lead zirconate...titanate ceramic material with nickel surface electrodes. The elements, nominally measuring 1.0 x 0.5 x 0.010 inch, were epoxied directly to the upper...DAMPING- 0.53 Z RECURO Me. 221 :&CORD ND. 2Z2 RECORD NO. 23) O23 MUg 1 (MLI 6) Ku 2 I.D Si MuM 3 (1A 80 R"T 26 1U SG AP $S SCM AP VMS SGS AMP P94 SGC

An evaluation of total and inhalable samplers for the collection of wood dust in three wood products industries.

PubMed

Harper, Martin; Muller, Brian S

2002-10-01

In 1998 the American Conference for Governmental Industrial Hygienists (ACGIH) proposed size selective sampling for wood dust based on the inhalable fraction. Thus the proposed threshold limit values (TLVs) require the use of a sampler whose performance matches the inhalable convention. The Institute of Occupational Medicine (IOM) sampler has shown good agreement with the inhalable convention under controlled conditions, and the Button sampler, developed by the University of Cincinnati, has shown reasonable agreement in at least one laboratory study. The Button sampler has not been previously evaluated under wood working conditions, and the IOM has been shown to sample more mass than expected when compared to the standard closed-face cassette, which may be due to the collection of very large particles in wood working environments. Some projectile particles may be > 100 microm aerodynamic diameter and thus outside the range of the convention. Such particles, if present, can bias the estimates of concentration considerably. This study is part of an on-going research focus into selecting the most appropriate inhalable sampler for use in these industries, and to examine the impact of TLV changes. This study compared gravimetric analyses (National Institute of Occupational Safety and Health Method 0500) of side-by-side personal samples using the Button, IOM, and 37 mm closed-face cassette (CFC) under field-use conditions. A total of 51 good sample pairs were collected from three wood products industries involved in the manufacturing of cabinets, furniture, and shutters. Paired t-tests were run on each sample pair using Statistical Package for the Social Sciences (SPSS) version 10. The IOM and the CFC measured statistically different concentrations (p < 0.0005, n = 16). The IOM and Button measured statistically different concentrations (p = 0.020, n = 12). The Button and CFC did not measure statistically different concentrations of wood dust (p = 0.098, n = 23). Sampler ratios for IOM/CFC pairs ranged from 1.19-19 (median 3.35). Sampler ratios for IOM/Button pairs ranged from 0.49-163 (median 3.15). Sampler ratios for CFC/Button pairs ranged from 0.36-27 (median 1.2). In all cases, higher ratios were associated with higher concentrations. The median relative difference between the IOM's and CFC's is in accord with prior field studies in woodworking environments, and, taken together, the data imply a conversion factor greater than the 2.5 normally applied to CFC results to approximate inhalable values, as measured by the IOM. Raising the limit values by approximately 50% appears warranted for this particular situation of inhalable wood dust measured by the IOM. The IOM/Button and CFC/Button ratios were unexpectedly low, which may be due to the exclusion of very large particles, collected by the IOM and CFC samplers. Further work is required to explain these results.

Disturbance of semantic processing in temporal lobe epilepsy demonstrated with scalp ERPs.

PubMed

Miyamoto, T; Katayama, J I; Kohsaka, M; Koyama, T

2000-12-01

We investigated event-related potentials (N400, LPC and CNV) elicited in temporal lobe epilepsy (TLE) patients and control subjects from scalp electrodes, using a word-pair category matching paradigm. Each prime consisted of a Japanese noun (constructed from 2-4 characters of the Hiragana) followed by a Chinese character (Kanji) as the target, the latter representing one of five semantic categories. There were two equally probable target conditions: match or mismatch. Each target was preceded by a prime, either belonging to, or not belonging to, the same semantic category. The subjects were required to respond with a specified button press to the given target, according to the condition. We found RTs to be longer under the mismatch condition in both subject groups. The N400 amplitude was reduced in TLE subjects under both conditions, although LPC and CNV amplitudes showed no significant differences. These results suggest that scalp N400 is capable of demonstrating disturbance of semantic processing in TLE non-invasively. Copyright 2000 BEA Trading Ltd.

Blood-gas analyzer calibration and quality control using a precision gas-mixing instrument.

PubMed

Wallace, W D; Clark, J S; Cutler, C A

1981-08-01

We describe a new instrument that performs on-site mixing of oxygen (O2), carbon dioxide (CO2), and nitrogen (N2) to create compositions that can replace gases from standard premixed cylinders. This instrument yields accurate and predictable gas mixtures that can be used for two-point gas calibration of blood gas/pH analyzers or for liquid tonometry of either an aqueous buffer or blood used as quality-control material on blood-gas electrodes. The desired mixture of O2, CO2, and N2 is produced by microprocessor control of the sequential open-times on three solenoid valves that meter these pure gases through a common small-bore orifice. Any combination of O2 and CO2 can be chosen by dialing the front panel thumbwheels and pressing a button. Gas chromatographic evaluation of this gas-mixing instrument demonstrates its accuracy and precision to be better than +/- 0.1% absolute full scale for O2, CO2, and N2, making this instrument calibration and tonometry.

78 FR 32081 - Airworthiness Directives; Aircraft Industries a.s. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-29

... Injection System WATER INJECTION circuit ON breakter. TCL TQ=min. 60% WATER INJECTION/ON push- Push and hold till amber button. WATER INJECTION signal comes on (on the front control panel) Before throttling back power: WATER INJECTION/OFF push- Push and check amber button. WATER INJECTION signal extinguishes...

Adapting the eButton to the abilities of children for diet assessment

USDA-ARS?s Scientific Manuscript database

Dietary assessment is fraught with error among adults and especially among children. Innovative technology may provide more accurate assessments of dietary intake. One recently available innovative method is a camera worn on the chest (called an eButton) that takes images of whatever is in front of ...

Dietary supplementation with white button mushroom augments the protective immune response to Salmonella vaccine in mice

USDA-ARS?s Scientific Manuscript database

We previously showed that dietary white button mushrooms (WBM) enhanced natural killer cell activity and that in vitro WBM supplementation promotes maturation and function of dendritic cells (DC). The current study investigated whether WBM consumption would enhance pathogen-specific immune response ...

James Webb Telescope

Science.gov Websites

. solarsystem mobile thumbnail solarystem mobile button Webb will monitor the weather and atmospheres of the mobile thumbnail exoplanets-weather mobile button Webb will search for signs of life-sustaining water on planets beyond our solar system, and help us learn how planets form. blackholes mobile thumbnail

The Haida Button Blanket.

ERIC Educational Resources Information Center

Johnson, Vesta

In the Haida nation, there are two phratries, Eagle and Raven, divided into a number of clans sharing one or more emblems. These emblems, inherited from the mother's line, adorn the button blankets which are the traditional ceremonial robes that serve to identify the family of the wearer. Written instructions and diagrams guide students in…

The Button Project

ERIC Educational Resources Information Center

Armstrong, Charley

2005-01-01

In this article, the author describes The Button Project. It started as a dream, a need to educate future generations about the Holocaust, to teach tolerance, and to remember the past. Under the auspices of the Jewish Federation of Peoria, a small band of people joined together with the goal of teaching people about the Holocaust so that it will…

Utility of eButton images for identifying food preparation behaviors and meal-related tasks in adolescents

USDA-ARS?s Scientific Manuscript database

Food preparation skills may encourage healthy eating. Traditional assessment of child food preparation employs self- or parent proxy-reporting methods, which are prone to error. The eButton is a wearable all-day camera that has promise as an objective, passive method for measuring child food prepara...

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, ...

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

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, A MAN-MADE SUBSTANCE, WAS RARE. SCRAPS RESULTING FROM PRODUCTION AND PLUTONIUM RECOVERED FROM RETIRED NUCLEAR WEAPONS WERE REPROCESSED INTO VALUABLE PURE-PLUTONIUM METAL (9/19/73). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

"Urgency tip": a portable patient-activated device for objective measurement of urinary urgency.

PubMed

Kobayashi, Hideki; Araki, Isao; Tsuchida, Takayuki; Zakoji, Hidenori; Mikami, Yuki; Takeda, Masayuki; Kiyohiro, Noriaki

2007-03-01

For clinical practice and research of overactive bladder syndrome, it is essential to evaluate urgency symptoms in daily life. We have developed a portable patient-activated device to record bladder sensations. This electronic device is pocket-size and light, with five grading buttons and another button for cancellation.

46 CFR 121.510 - Recommended emergency broadcast instructions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Immediate Danger to Life or Property. (4) Say: “THIS IS (INSERT VESSEL'S NAME), (INSERT VESSEL'S NAME), (INSERT VESSEL'S NAME), (INSERT VESSEL'S CALL SIGN), OVER.” (5) Release the microphone button briefly and... 16 VHF and 2182 kHz on SSB are for emergency and calling purposes only.) (3) Press microphone button...

A size dependent dynamic model for piezoelectric nanogenerators: effects of geometry, structural and environmental parameters

NASA Astrophysics Data System (ADS)

Sadeghzadeh, Sadegh; Farshad Mir Saeed Ghazi, Seyyed

2018-03-01

Piezoelectric Nanogenerator (PENG) is one of the novel energy harvester systems that recently, has been a subject of interest for researchers. By the use of nanogenerators, it’s possible to harvest different forms of energy in the environment like mechanical vibrations and generate electricity. The structure of a PENG consists of vertical arrays of nanowires between two electrodes. In this paper, dynamic analysis of a PENG is studied numerically. The modified couple stress theory which includes one length scale material parameter is used to study the size-dependent behavior of PENGs. Then, by application of a complete form of linear hybrid piezoelectric—pyroelectric equations, and using the Euler-Bernoulli beam model, the equations of motion has been derived. Generalized Differential Quadrature (GDQ) method was employed to solve the equations of motion. The effect of damping ratio, temperature rise, excitation frequency and length scale parameter was studied. It was found that the PENG voltage maximizes at the resonant frequency of nanowire. The temperature rise has a significant effect on PENG’s efficiency. When temperature increases about 10 {{K}}, the maximum voltage increases about 26%. Increasing the damping ratio, the maximum voltage decreases gradually.

The effects of patch-potentials on the gravity probe B gyroscopes.

PubMed

Buchman, S; Turneaure, J P

2011-07-01

Gravity probe B (GP-B) was designed to measure the geodetic and frame dragging precessions of gyroscopes in the near field of the Earth using a drag-free satellite in a 642 km polar orbit. Four electrostatically suspended cryogenic gyroscopes were designed to measure the precession of the local inertial frame of reference with a disturbance drift of about 0.1 marc sec/yr-0.2 marc sec/yr. A number of unexpected gyro disturbance effects were observed during the mission: spin-speed and polhode damping, misalignment and roll-polhode resonance torques, forces acting on the gyroscopes, and anomalies in the measurement of the gyro potentials. We show that all these effects except possibly polhode damping can be accounted for by electrostatic patch potentials on both the gyro rotors and the gyro housing suspension and ground-plane electrodes. We express the rotor and housing patch potentials as expansions in spherical harmonics Y(l,m)(θ,φ). Our analysis demonstrates that these disturbance effects are approximated by a power spectrum for the coefficients of the spherical harmonics of the form V(0)(2)/l(r) with V(0) ≈ 100 mV and r ≈ 1.7.

Harvesting keratolimbal allografts from corneoscleral buttons: a novel application of cyanoacrylate adhesive.

PubMed

Lim, L T; Bhatt, P R; Ramaesh, K

2008-11-01

To describe an alternative and novel technique using cyanoacrylate glue to achieve successful limbal tissue dissection, from an organ culture media stored corneoscleral button, without an artificial anterior chamber. A donor corneoscleral button (leftover from penetrating keratoplasty) was divided into two equal semicircular halves. A thick layer of tissue adhesive (N-butyl-2-cyanoacrylate) was spread on a sterile rubber block (the under surface of the donor punch). One half of the donor corneoscleral rim was placed epithelial side up on the adhesive and allowed to attach firmly to the block. This composite provided stability to the donor rim allowing lamellar dissection of the limbal tissue to be performed without damaging the limbal epithelium. Regular, partial-thickness limbal tissue was obtained. There was no histological evidence of glue or cellular toxicity of the harvested limbal stem cells. This harvested tissue had been grafted successfully in patients with limbal stem cell deficiency also undergoing keratoplasty. Tissue adhesive can be a simple, effective and useful tool in the dissection and harvesting of corneal limbal stem cell allografts from corneoscleral buttons stored in organ culture media.

Enhancing stability of essential oils by microencapsulation for preservation of button mushroom during postharvest

PubMed Central

Alikhani-Koupaei, Majid; Mazlumzadeh, Meisam; Sharifani, Mohamadmehdi; Adibian, Mohamad

2014-01-01

Fresh button mushrooms (Agaricus bisporus L.) are sensitive to browning, water loss, and microbial attack. The short shelf-life of mushrooms is an impediment to the distribution and marketing of the fresh product. Essential oils outstand as an alternative to chemical preservatives and their use in foods meets the demands of consumers for natural products. To resolve controlled release of oil and increase in antioxidant and antimicrobial activities, the oil was incorporated into microcapsules. Effects of microcapsulated thyme (Thymus vulgaris L.) and rosemary (Rosmarinus officinalis L.) on quality of fresh button mushroom were compared. Physicochemical qualities were evaluated during 15 days of storage at 4 ± 0.5°C. All treatments prevented product weight loss and decrease in polyphenoloxidase and peroxidase activities during storage. Color and firmness, microbiological analysis, and total phenolic content caused the least change. With use of microencapsulated oils, mushrooms were within acceptable limits during 10 days of storage. Microencapsulated rosemary oil produced the highest beneficial effects and has potential to improve quality of button mushrooms and extend shelf-life. PMID:25473510

Further miniaturisation of the Thermochron iButton to create a thermal bio-logger weighing 0.3 g.

PubMed

Virens, Josef; Cree, Alison

2018-06-05

Thermochron iButtons are commonly used by thermal biologists to continuously measure body temperature from animals. However, if unmodified, these devices are of a size that limits their use with very small animals. To allow iButtons to be used to study smaller species, methods to miniaturise them by 61% have been previously described. We present a method to reduce iButton mass by a further 71%. The modified devices have a shorter battery life, but the minimum size of vertebrates able to carry the devices is reduced from 28.9 g to 6.6 g, if the arbitrary, yet widely cited, maximum of 5% body mass for attached devices is adhered to. We demonstrate the application of our method by recording surface temperatures of captive and wild skinks and show that captive cockroaches weighing 0.8 g are also able to carry the device. We believe this to be the first time that temperature data have been recorded from an insect in this way. © 2018. Published by The Company of Biologists Ltd.

Aniridia-related keratopathy: Structural changes in naïve and transplanted corneal buttons

PubMed Central

Stenevi, Ulf; Pedrosa Domellöf, Fátima

2018-01-01

Background To study structural changes in naïve and surgically treated corneas of aniridia patients with advanced aniridia-related keratopathy (ARK). Methods and findings Two naïve corneal buttons from patients with advanced ARK submitted to penetrating keratoplasty for the first time, one corneal button from an ARK patient that had undergone a keratolimbal allograft (KLAL), two corneal buttons from ARK patients who had previously undergone centered or decentered transplantation and were now retransplanted and two adult healthy donor control corneas were processed for immunohistochemistry. Antibodies against extracellular matrix components in the stroma and in the epithelial basement membrane (collagen I and IV, collagen receptor α11 integrin and laminin α3 chain), markers of fibrosis, wound healing and vascularization (fibronectin, tenascin-C, vimentin, α-SMA and caveolin-1), cell division (Ki-67) and macrophages (CD68) were used. Naïve ARK, KLAL ARK corneas and transplanted corneal buttons presented similar histopathological changes with irregular epithelium and disruption or absence of epithelial basal membrane. There was a loss of the orderly pattern of collagen lamellae and absence of collagen I in all ARK corneas. Vascularization was revealed by the presence of caveolin-1 and collagen IV in the pannus of all ARK aniridia corneas. The changes observed in decentered and centered transplants were analogous. Conclusions Given the similar pathological features of all cases, conditions inherent to the host seem to play an important role on the pathophysiology of the ARK in the long run. PMID:29889891

Aniridia-related keratopathy: Structural changes in naïve and transplanted corneal buttons.

PubMed

Vicente, André; Byström, Berit; Lindström, Mona; Stenevi, Ulf; Pedrosa Domellöf, Fátima

2018-01-01

To study structural changes in naïve and surgically treated corneas of aniridia patients with advanced aniridia-related keratopathy (ARK). Two naïve corneal buttons from patients with advanced ARK submitted to penetrating keratoplasty for the first time, one corneal button from an ARK patient that had undergone a keratolimbal allograft (KLAL), two corneal buttons from ARK patients who had previously undergone centered or decentered transplantation and were now retransplanted and two adult healthy donor control corneas were processed for immunohistochemistry. Antibodies against extracellular matrix components in the stroma and in the epithelial basement membrane (collagen I and IV, collagen receptor α11 integrin and laminin α3 chain), markers of fibrosis, wound healing and vascularization (fibronectin, tenascin-C, vimentin, α-SMA and caveolin-1), cell division (Ki-67) and macrophages (CD68) were used. Naïve ARK, KLAL ARK corneas and transplanted corneal buttons presented similar histopathological changes with irregular epithelium and disruption or absence of epithelial basal membrane. There was a loss of the orderly pattern of collagen lamellae and absence of collagen I in all ARK corneas. Vascularization was revealed by the presence of caveolin-1 and collagen IV in the pannus of all ARK aniridia corneas. The changes observed in decentered and centered transplants were analogous. Given the similar pathological features of all cases, conditions inherent to the host seem to play an important role on the pathophysiology of the ARK in the long run.

Utility of eButton images for identifying food preparation behaviors and meal-related tasks in adolescents.

PubMed

Raber, Margaret; Patterson, Monika; Jia, Wenyan; Sun, Mingui; Baranowski, Tom

2018-02-24

Food preparation skills may encourage healthy eating. Traditional assessment of child food preparation employs self- or parent proxy-reporting methods, which are prone to error. The eButton is a wearable all-day camera that has promise as an objective, passive method for measuring child food preparation practices. This paper explores the feasibility of the eButton to reliably capture home food preparation behaviors and practices in a sample of pre- and early adolescents (ages 9 to 13). This is a secondary analysis of two eButton pilot projects evaluating the dietary intake of pre- and early adolescents in or around Houston, Texas. Food preparation behaviors were coded into seven major categories including: browsing, altering food/adding seasoning, food media, meal related tasks, prep work, cooking and observing. Inter-coder reliability was measured using Cohen's kappa and percent agreement. Analysis was completed on data for 31 participants. The most common activity was browsing in the pantry or fridge. Few participants demonstrated any food preparation work beyond unwrapping of food packages and combining two or more ingredients; actual cutting or measuring of foods were rare. Although previous research suggests children who "help" prepare meals may obtain some dietary benefit, accurate assessment tools of food preparation behavior are lacking. The eButton offers a feasible approach to food preparation behavior measurement among pre- and early adolescents. Follow up research exploring the validity of this method in a larger sample, and comparisons between cooking behavior and dietary intake are needed.

Fixation of the Achilles tendon insertion using suture button technology.

PubMed

Fanter, Nathan J; Davis, Edward W; Baker, Champ L

2012-09-01

In the operative treatment of Achilles insertional tendinopathy, no guidelines exist concerning which form of fixation of the Achilles tendon insertion is superior. Transcalcaneal drill pin passage does not place any major plantar structures at risk, and the addition of a Krackow stitch and suture button to the fixation technique provides a significant increase in ultimate load to failure in Achilles tendon insertional repairs. Controlled laboratory study. The Achilles tendon insertions in 6 fresh-frozen cadaveric ankles were detached, and transcalcaneal drill pins were passed. Plantar dissection took place to evaluate the drill pin relationship to the plantar fascia, lateral plantar nerve and artery, flexor digitorum longus tendon, and master knot of Henry. The Achilles tendons were then repaired with a double-row suture anchor construct alone or with a suture button and Krackow stitch added to the double-row suture anchor construct. The repairs were then tested to maximum load to failure at 20 mm/min. The mode of failure was recorded, and the mean maximum load to failure was assessed using the Student t test for distributions with equal variance. Transcalcaneal drill pin passage did not place any selected anatomic structures at risk. The mean maximum load to failure for the suture bridge group was 239.2 N; it was 391.4 N for the group with the suture button (P = .014). The lateral plantar artery was the structure placed at greatest risk from drill pin placement, with a mean distance of 22.7 mm (range, 16.5-29.2 mm) between the pin and artery. In this laboratory study, transcalcaneal drill pin passage appeared to be anatomically safe, and the use of suture button technology with a Krackow stitch for Achilles tendon insertional repair significantly increased repair strength. Achilles tendon insertional repair with suture button fixation and a Krackow stitch may facilitate the earlier institution of postoperative rehabilitation and improve clinical outcomes.

Automatic needle segmentation in 3D ultrasound images using 3D improved Hough transform

NASA Astrophysics Data System (ADS)

Zhou, Hua; Qiu, Wu; Ding, Mingyue; Zhang, Songgen

2008-03-01

3D ultrasound (US) is a new technology that can be used for a variety of diagnostic applications, such as obstetrical, vascular, and urological imaging, and has been explored greatly potential in the applications of image-guided surgery and therapy. Uterine adenoma and uterine bleeding are the two most prevalent diseases in Chinese woman, and a minimally invasive ablation system using a needle-like RF button electrode is widely used to destroy tumor cells or stop bleeding. To avoid accidents or death of the patient by inaccurate localizations of the electrode and the tumor position during treatment, 3D US guidance system was developed. In this paper, a new automated technique, the 3D Improved Hough Transform (3DIHT) algorithm, which is potentially fast, accurate, and robust to provide needle segmentation in 3D US image for use of 3D US imaging guidance, was presented. Based on the coarse-fine search strategy and a four parameter representation of lines in 3D space, 3DIHT algorithm can segment needles quickly, accurately and robustly. The technique was evaluated using the 3D US images acquired by scanning a water phantom. The segmentation position deviation of the line was less than 2mm and angular deviation was much less than 2°. The average computational time measured on a Pentium IV 2.80GHz PC computer with a 381×381×250 image was less than 2s.

Automatic needle segmentation in 3D ultrasound images using 3D Hough transform

NASA Astrophysics Data System (ADS)

Zhou, Hua; Qiu, Wu; Ding, Mingyue; Zhang, Songgeng

2007-12-01

3D ultrasound (US) is a new technology that can be used for a variety of diagnostic applications, such as obstetrical, vascular, and urological imaging, and has been explored greatly potential in the applications of image-guided surgery and therapy. Uterine adenoma and uterine bleeding are the two most prevalent diseases in Chinese woman, and a minimally invasive ablation system using an RF button electrode which is needle-like is being used to destroy tumor cells or stop bleeding currently. Now a 3D US guidance system has been developed to avoid accidents or death of the patient by inaccurate localizations of the electrode and the tumor position during treatment. In this paper, we described two automated techniques, the 3D Hough Transform (3DHT) and the 3D Randomized Hough Transform (3DRHT), which is potentially fast, accurate, and robust to provide needle segmentation in 3D US image for use of 3D US imaging guidance. Based on the representation (Φ , θ , ρ , α ) of straight lines in 3D space, we used the 3DHT algorithm to segment needles successfully assumed that the approximate needle position and orientation are known in priori. The 3DRHT algorithm was developed to detect needles quickly without any information of the 3D US images. The needle segmentation techniques were evaluated using the 3D US images acquired by scanning water phantoms. The experiments demonstrated the feasibility of two 3D needle segmentation algorithms described in this paper.

Portable Electromyograph

NASA Technical Reports Server (NTRS)

De Luca, Gianluca; De Luca, Carlo J.; Bergman, Per

2004-01-01

A portable electronic apparatus records electromyographic (EMG) signals in as many as 16 channels at a sampling rate of 1,024 Hz in each channel. The apparatus (see figure) includes 16 differential EMG electrodes (each electrode corresponding to one channel) with cables and attachment hardware, reference electrodes, an input/output-and-power-adapter unit, a 16-bit analog-to-digital converter, and a hand-held computer that contains a removable 256-MB flash memory card. When all 16 EMG electrodes are in use, full-bandwidth data can be recorded in each channel for as long as 8 hours. The apparatus is powered by a battery and is small enough that it can be carried in a waist pouch. The computer is equipped with a small screen that can be used to display the incoming signals on each channel. Amplitude and time adjustments of this display can be made easily by use of touch buttons on the screen. The user can also set up a data-acquisition schedule to conform to experimental protocols or to manage battery energy and memory efficiently. Once the EMG data have been recorded, the flash memory card is removed from the EMG apparatus and placed in a flash-memory- card-reading external drive unit connected to a personal computer (PC). The PC can then read the data recorded in the 16 channels. Preferably, before further analysis, the data should be stored in the hard drive of the PC. The data files are opened and viewed on the PC by use of special- purpose software. The software for operation of the apparatus resides in a random-access memory (RAM), with backup power supplied by a small internal lithium cell. A backup copy of this software resides on the flash memory card. In the event of loss of both main and backup battery power and consequent loss of this software, the backup copy can be used to restore the RAM copy after power has been restored. Accessories for this device are also available. These include goniometers, accelerometers, foot switches, and force gauges.

No significant effect of transcranial direct current stimulation (tDCS) found on simple motor reaction time comparing 15 different simulation protocols.

PubMed

Horvath, Jared Cooney; Carter, Olivia; Forte, Jason D

2016-10-01

Research exploring the behavioral impact of transcranial direct current stimulation (tDCS) over M1 has produced homogenous results. The most common explanations to address this homogeneity concerns the differential impact of varied tDCS parameters (such as stimulation intensity or electrode montage). To explore this, we systematically examined the effects of 15 different tDCS protocols on a well-elucidated neurobehavioral system: simple visual motor reaction time (smRT). For the initial phase of this study, 150 healthy participants were randomly assigned to one of 5 experimental groups (2mA anodal, 2mA cathodal, 1mA anodal, 1mA cathodal, or sham) across 3 different conditions (orbitofrontal, bilateral, or extracephalic reference electrode location). The active electrode was always placed over M1 and tDCS lasted for 20min. Starting ~5min prior to stimulation and running continuously for ~30min, participants were repeatedly presented with a visual cue centered on a computer monitor and asked to press a response button as quickly as possible at stimulus onset (stimuli number: 100 pre-, 400 during-, and 100-post stimulation - interstimulus interval: 1-3s). Ex-gaussian distribution curves, miss, and error rates were determined for each normalized batch of 100 RTs and compared using a two-way ANOVA. As the largest group differences were seen with 2mA anodal (compared to sham) stimulation using an orbitofrontal montage, an additional 60 healthy participants were recruited to further test for significance in this condition. No significant impact of tDCS was seen on any parameter of smRT distribution, error rate, or miss rate, regardless of polarity, stimulation intensity, electrode montage, or stimulation-to-task relationship. Our results suggest that tDCS over M1 might not have a predictable or reliable effect on short duration smRT. Our results raise interesting questions regarding the mechanisms by which tDCS might modulate more complex motor behaviors. Additional research utilizing multiple tDCS protocols as undertaken here will help address and clarify these concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

Napoleon's Buttons: Teaching the Role of Chemistry in History

ERIC Educational Resources Information Center

Samet, Cindy; Higgins, Pamela J.

2005-01-01

A course designed on the theme of Napoleon's Buttons, which states that there is a connection between the chemical structure of a compound and its pivotal moments in history affecting the development of society is explained. Students liked the book choice for the course because the focus was not on straight chemistry, but the intersection of…

Designing a Machinery Control System (MCS) Security Testbed

DTIC Science & Technology

2014-09-01

IO LAB” button and verify the display looks as follows: 95 Figure F22 . “Ready State” (and start state)of the DIOL as displayed at the HMI...After verification that the HMI screen looks like Figure F22 , click on the “Back to Home Screen” button and return to the HMI “Home” screen as seen

78 FR 66099 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-04

... every year (a) by an ophthalmologist or optometrist who attests that the vision in the better eye... showing that the vision in the better eye continues to meet the requirement specified at 49 CFR 391.41(b... click the search button. When the new screen appears, click on the blue ``Comment Now!'' button on the...

Peach fruit set and buttoning after spring frost

USDA-ARS?s Scientific Manuscript database

A spring frost occurred on 29 Mar. 2015 at the USDA-ARS Byron station after three weeks of blooming when most fruitlets were forming. Due to severe fruitlet drop, the overall fruit set on a scale of 0-9 was substantially reduced, from 5.61 averaged in 2014 to 2.61 in 2015. In addition, buttons (abno...

Mechanical Design of Metal Dome for Industrial Application

NASA Astrophysics Data System (ADS)

Jin-Chee Liu, Thomas; Chen, Li-Wei; Lin, Nai-Pin

2018-02-01

In this paper, the mechanical design of metal domes is studied using finite element analysis. The snap-through behavior of a practical button design that uses a metal dome is found. In addition, the individual click ratio and maximum force for a variety of metal domes are determined. This paper provides guidance on button design for industrial engineers.

Tube support

DOEpatents

Mullinax, Jerry L.

1988-01-01

A tube support for supporting horizontal tubes from an inclined vertical support tube passing between the horizontal tubes. A support button is welded to the vertical support tube. Two clamping bars or plates, the lower edges of one bearing on the support button, are removably bolted to the inclined vertical tube. The clamping bars provide upper and lower surface support for the horizontal tubes.

The Newport Button: The Large Scale Replication Of Combined Three-And Two-Dimensional Holographic Images

NASA Astrophysics Data System (ADS)

Cowan, James J.

1984-05-01

A unique type of holographic imagery and its large scale replication are described. The "Newport Button", which was designed as an advertising premium item for the Newport Corporation, incorporates a complex overlay of holographic diffraction gratings surrounding a three-dimensional holographic image of a real object. The combined pattern is recorded onto a photosensitive medium from which a metal master is made. The master is subsequently used to repeatedly emboss the pattern into a thin plastic sheet. Individual patterns are then die cut from the metallized plastic and mounted onto buttons. A discussion is given of the diffraction efficiencies of holograms made in this particular fashion and of the special requirements of the replication process.

Impact of metal gates on remote phonon scattering in titanium nitride/hafnium dioxide n-channel metal-oxide-semiconductor field effect transistors-low temperature electron mobility study

NASA Astrophysics Data System (ADS)

Maitra, Kingsuk; Frank, Martin M.; Narayanan, Vijay; Misra, Veena; Cartier, Eduard A.

2007-12-01

We report low temperature (40-300 K) electron mobility measurements on aggressively scaled [equivalent oxide thickness (EOT)=1 nm] n-channel metal-oxide-semiconductor field effect transistors (nMOSFETs) with HfO2 gate dielectrics and metal gate electrodes (TiN). A comparison is made with conventional nMOSFETs containing HfO2 with polycrystalline Si (poly-Si) gate electrodes. No substantial change in the temperature acceleration factor is observed when poly-Si is replaced with a metal gate, showing that soft optical phonons are not significantly screened by metal gates. A qualitative argument based on an analogy between remote phonon scattering and high-resolution electron energy-loss spectroscopy (HREELS) is provided to explain the underlying physics of the observed phenomenon. It is also shown that soft optical phonon scattering is strongly damped by thin SiO2 interface layers, such that room temperature electron mobility values at EOT=1 nm become competitive with values measured in nMOSFETs with SiON gate dielectrics used in current high performance processors.

A Semianalytical Ion Current Model for Radio Frequency Driven Collisionless Sheaths

NASA Technical Reports Server (NTRS)

Bose, Deepak; Govindan, T. R.; Meyyappan, M.; Arnold, Jim (Technical Monitor)

2001-01-01

We propose a semianalytical ion dynamics model for a collisionless radio frequency biased sheath. The model uses bulk plasma conditions and electrode boundary condition to predict ion impact energy distribution and electrical properties of the sheath. The proposed model accounts for ion inertia and ion current modulation at bias frequencies that are of the same order of magnitude as the ion plasma frequency. A relaxation equation for ion current oscillations is derived which is coupled with a damped potential equation in order to model ion inertia effects. We find that inclusion of ion current modulation in the sheath model shows marked improvements in the predictions of sheath electrical properties and ion energy distribution function.

How preschoolers and adults represent their joint action partner's behavior.

PubMed

Sacheli, Lucia Maria; Meyer, M; Hartstra, E; Bekkering, H; Hunnius, S

2017-10-24

We investigated the cognitive mechanisms underlying turn-taking joint action in 42-month-old children (Experiment 1) and adults (Experiment 2) using a behavioral task of dressing a virtual bear together. We aimed to investigate how participants represent a partners' behavior, i.e., in terms of specific action kinematics or of action effects. The bear was dressed by pressing a smaller and a bigger button. In the Action-response task, instructions asked participants to respond to the partner by pressing the same or opposite button; in the Action-effect task they had to respond to the partner's action effect by dressing the bear with the lacking part of the clothing, which in some cases implied pressing the same button and in other cases implied pressing the opposite button. In 50% of the trials, the partner's association between each button and the ensuing effect (dressing the bear with t-shirt or pants) was reversed, while it never changed for participants. Both children and adults showed no effect of physical congruency of actions, but showed impaired performance in the Action-effect task if their partner achieved her effect through a different action-effect association than their own. These results suggest that, when encoding their partner's actions, agents are influenced by action-effect associations that they learnt through their own experience. While interference led to overt errors in children, it caused longer reaction times in adults, suggesting that a flexible cognitive control (that is still in development in young children) is required to take on the partner's perspective.

Automatic food detection in egocentric images using artificial intelligence technology.

PubMed

Jia, Wenyan; Li, Yuecheng; Qu, Ruowei; Baranowski, Thomas; Burke, Lora E; Zhang, Hong; Bai, Yicheng; Mancino, Juliet M; Xu, Guizhi; Mao, Zhi-Hong; Sun, Mingui

2018-03-26

To develop an artificial intelligence (AI)-based algorithm which can automatically detect food items from images acquired by an egocentric wearable camera for dietary assessment. To study human diet and lifestyle, large sets of egocentric images were acquired using a wearable device, called eButton, from free-living individuals. Three thousand nine hundred images containing real-world activities, which formed eButton data set 1, were manually selected from thirty subjects. eButton data set 2 contained 29 515 images acquired from a research participant in a week-long unrestricted recording. They included both food- and non-food-related real-life activities, such as dining at both home and restaurants, cooking, shopping, gardening, housekeeping chores, taking classes, gym exercise, etc. All images in these data sets were classified as food/non-food images based on their tags generated by a convolutional neural network. A cross data-set test was conducted on eButton data set 1. The overall accuracy of food detection was 91·5 and 86·4 %, respectively, when one-half of data set 1 was used for training and the other half for testing. For eButton data set 2, 74·0 % sensitivity and 87·0 % specificity were obtained if both 'food' and 'drink' were considered as food images. Alternatively, if only 'food' items were considered, the sensitivity and specificity reached 85·0 and 85·8 %, respectively. The AI technology can automatically detect foods from low-quality, wearable camera-acquired real-world egocentric images with reasonable accuracy, reducing both the burden of data processing and privacy concerns.

Suture Button Fixation Treatment of Chronic Lisfranc Injury in Professional Dancers and High-Level Athletes.

PubMed

Charlton, Timothy; Boe, Chelsea; Thordarson, David B

2015-12-01

Chronic Lisfranc injury is a subtle and severe injury in high-level athletes, including dancers. This patient population is generally intolerant of intra-articular screw fixation and can develop significant post-traumatic arthritis with potentially career ending complications. Flexible fixation with suture-button devices provides potential restoration of physiologic motion at the joint, with appropriate support for healing that may facilitate return to en pointe activities for dancers. We hypothesized that the suture-button device would restore motion at the Lisfranc joint and allow for return to activities in this particular population without the limitations and complications of rigid fixation. We operated on seven dancers and high-level athletes with diagnosed Lisfranc injuries by installing a suture-button device. All patients had failed conservative management after late presentation. They were allowed to return to sport in 6 months, preoperative and postoperative American Orthopaedic Foot and Ankle Score (AOFAS) foot scores were obtained, and patients were followed for a minimum of 15 months. All seven returned to full activities in 6 months, with radiographic evidence of fixation and no complications to date. AOFAS foot scores improved from an average of 65 preoperatively to an average of 97 postoperatively at latest follow-up. It is concluded that flexible fixation with suture-button type device represents a viable alternative to screw fixation or fusion that may allow dancers and athletes to return to previous levels of activity after Lisfranc injury. This case series represents to our knowledge the first application of this device to a unique population that requires flexibility at the Lisfranc joint for performance.

Spicing Things up by Adding Color and Relieving Pain: The Use of "Napoleon's Buttons" in Organic Chemistry

ERIC Educational Resources Information Center

Bucholtz, Kevin M.

2011-01-01

For some students, organic chemistry can be a distant subject and unrelated to any courses they have seen in their college careers. To develop a more contextual learning experience in organic chemistry, an additional text, "Napoleon's Buttons: 17 Molecules That Changed History," by Penny Le Couteur and Jay Burreson, was incorporated as a…

Miniature Two-Axis Joystick Controller

NASA Technical Reports Server (NTRS)

Hollow, R.

1983-01-01

Novel movable-button-actuated self-centering controller uses optoelectronics to produce X and Y signals for aircraft control. In addition to be extremely compact, device puts our voltages having high signal-to-noise ratio, especially at critical center position where in many controllers this ratio is poorest. Combination of new saddle-shaped button and positive centering gives "feel" and "breakout" met with pilot approval.

--No Title--

Science.gov Websites

:#ccc;text-align:center;padding:5px}.upper_button{text-align:right;padding-bottom:5px}.side_button[type ;width:175px;text-align:left;font-weight:bold;overflow:hidden}.left_head_title_alt{float:left;width:175px ;text-align:left;font-weight:bold;line-height:16px;margin-top:3px;padding-top:0}.left_head_add

Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche

Treesearch

Emmanuelle Morin; Annegret Kohler; Adam R. Baker; Marie Foulongne-Oriol; Vincent Lombard; Laszlo G. Nagy; Robin A. Ohm; Aleksandrina Patyshakuliyeva; Annick Brun; Andrea L. Aerts; Andrew M. Bailey; Christophe Billette; Pedro M. Coutinho; Greg Deakin; Harshavardhan Doddapaneni; Dimitrios Floudas; Jane Grimwood; Kristiina Hild& #233; n; Ursula K& #252; es; Kurt M. LaButti; Alla Lapidus; Erika A. Lindquist; Susan M. Lucas; Claude Murat; Robert W. Riley; Asaf A. Salamov; Jeremy Schmutz; Venkataramanan Subrananian; Han A.B. W& #246; sten; Jianping Xu; Daniel C. Eastwood; Gary D. Foster; Anton S.M. Sonnenberg; Daniel Cullen; Ronald P. de Vries; Taina Lundell; David S. Hibbett; Bernard Henrissat; Kerry S. Burton; Richard W. Kerrigan; Michael P. Challen; Igor V. Grigoriev; Francis Martin

2012-01-01

Agaricus bisporus is the model fungus for the adaptation, persistence,and growth in the humic-rich leaf-litter environment. Aside from its ecological role, A. bisporus has been an important component of the human diet for over 200 y and worldwide cultivation of the "button mushroom" forms a multibillion dollar...

Don't wear that button out!

NASA Astrophysics Data System (ADS)

Jue, Brian J.; Bice, Michael D.

2013-07-01

As students explore the technological tools available to them for learning mathematics, some will eventually discover what happens when a function button is repeatedly pressed on a calculator. We explore several examples of this, presenting tabular and graphical results for the square root, natural logarithm and sine and cosine functions. Observed behaviour is proven and then discussed in the context of fixed points.

Using Buttons to Better Manage Online Presence: How One Academic Institution Harnessed the Power of Flair

ERIC Educational Resources Information Center

Dority Baker, Marcia L.

2013-01-01

This article provides a case study of how the University of Nebraska College of Law and Schmid Law Library use "buttons" to manage Law College faculty members' and librarians' online presence. Since Google is the primary search engine used to find information, it is important that librarians and libraries assist Web site visitors in…

--No Title--

Science.gov Websites

fixme{background-color:#ff0}.container-fluid{padding:0;margin:0}.hp{font-family:Roboto," }.hp-hero-text{position:absolute;text-shadow:1px 1px 1px rgba(150,150,150,1)}.hp-hero h2{color:#fff}.hp -hero button{color:#e3e3e3;font-size:10px;background:transparent;border:none}.hp-hero button:hover,.hp

Stimulus-dependent deliberation process leading to a specific motor action demonstrated via a multi-channel EEG analysis

PubMed Central

Henz, Sonja; Kutz, Dieter F.; Werner, Jana; Hürster, Walter; Kolb, Florian P.; Nida-Ruemelin, Julian

2015-01-01

The aim of the study was to determine whether a deliberative process, leading to a motor action, is detectable in high density EEG recordings. Subjects were required to press one of two buttons. In a simple motor task the subject knew which button to press, whilst in a color-word Stroop task subjects had to press the right button with the right index finger when meaning and color coincided, or the left button with the left index finger when meaning and color were disparate. EEG recordings obtained during the simple motor task showed a sequence of positive (P) and negative (N) cortical potentials (P1-N1-P2) which are assumed to be related to the processing of the movement. The sequence of cortical potentials was similar in EEG recordings of subjects having to deliberate over how to respond, but the above sequence (P1-N1-P2) was preceded by slowly increasing negativity (N0), with N0 being assumed to represent the end of the deliberation process. Our data suggest the existence of neurophysiological correlates of deliberative processes. PMID:26190987

Repair of Double Head Pectoralis Major Tendon Avulsion into its Native Footprint Using Bi-cortical EndoButtons and Tendon Sliding Technique.

PubMed

Prabhu, Jagadish; Faqi, Mohammed Khalid; Alkhalifa, Fahad; Tayara, Bader Kamal; Awad, Rashad Khamis

2017-01-01

Injuries to the pectoralis major muscle are relatively infrequent. The mechanism of injury is usually an eccentric shortening of the pectoralis major under heavy load, such as when performing a bench press exercise. We report a case that presented to us with a history of sudden pain in the left pectoral region while doing heavy bench press exercise. The patient sustained a type III D pectoralis muscle -tendon avulsion. Surgical repair was done through a bi-cortical tendon sliding technique using two cortical buttons. In this article we describe our modifications to the previously described surgical technique for the pectoralis major tendon repair using the EndoButton and tension - slide technique, aiming to overcome the possible complications.

Fixation of unstable type II clavicle fractures with distal clavicle plate and suture button.

PubMed

Johnston, Peter S; Sears, Benjamin W; Lazarus, Mark R; Frieman, Barbara G

2014-11-01

This article reports on a technique to treat unstable type II distal clavicle fractures using fracture-specific plates and coracoclavicular augmentation with a suture button. Six patients with clinically unstable type II distal clavicle fractures underwent treatment using the above technique. All fractures demonstrated radiographic union at 9.6 (8.4-11.6) weeks with a mean follow-up of 15.6 (12.4-22.3) months. American Shoulder and Elbow Surgeons, Penn Shoulder Score, and Single Assessment Numeric Evaluation scores were 97.97 (98.33-100), 96.4 (91-99), and 95 (90-100), respectively. One patient required implant removal. Fracture-specific plating with suture-button augmentation for type II distal clavicle fractures provides reliable rates of union without absolute requirement for implant removal.

Management of foreign body ingestions in children: button batteries and magnets.

PubMed

Kodituwakku, Ronan; Palmer, Sarah; Paul, Siba Prosad

2017-04-27

Foreign body ingestion and foreign body aspiration commonly affect young children between 6 months and 6 years. A large number of these events remain unwitnessed and asymptomatic while the swallowed foreign body traverses the gastrointestinal tract and is passed in the stool. Recent literature has shown an increase in morbidity associated with button battery and (neomydium) magnet ingestions in children, particularly over the last decade. Early identification and management in a time critical manner is required in cases where button batteries get lodged in the oesophagus or multiple magnets are swallowed. Deaths, although rare, have been reported with these dangerous foreign body ingestions in children where diagnoses were delayed. Nurses through their direct contact with children in different clinical settings play a vital role in managing foreign body ingestions.

Three-Dimensional NiCo2O4@MnMoO4 Core-Shell Nanoarrays for High-Performance Asymmetric Supercapacitors.

PubMed

Yuan, Yuliang; Wang, Weicheng; Yang, Jie; Tang, Haichao; Ye, Zhizhen; Zeng, Yujia; Lu, Jianguo

2017-10-10

Design of new materials with sophisticated nanostructure has been proven to be an efficient strategy to improve their properties in many applications. Herein, we demonstrate the successful combination of high electron conductive materials of NiCo 2 O 4 with high capacitance materials of MnMoO 4 by forming a core-shell nanostructure. The NiCo 2 O 4 @MnMoO 4 core-shell nanoarrays (CSNAs) electrode possesses high capacitance of 1169 F g -1 (4.24 F cm -2 ) at a current density of 2.5 mA cm -2 , obviously larger than the pristine NiCo 2 O 4 electrode. The asymmetric supercapacitors (ASCs), assembled with NiCo 2 O 4 @MnMoO 4 CSNAs as binder-free cathode and active carbon (AC) as anode, exhibit high energy density of 15 Wh kg -1 and high power density of 6734 W kg -1 . Cycle performance of NiCo 2 O 4 @MnMoO 4 CSNAs//AC ASCs, conducted at current density of 20 mA cm -2 , remain 96.45% of the initial capacitance after 10,000 cycles, demonstrating its excellent long-term cycle stability. Kinetically decoupled analysis reveals that the capacitive capacitance is dominant in the total capacitance of NiCo 2 O 4 @MnMoO 4 CSNAs electrode, which may be the reason for ultra long cycle stability of ASCs. Our assembled button ASC can easily light up a red LED for 30 min and a green LED for 10 min after being charged for 30 s. The remarkable electrochemical performance of NiCo 2 O 4 @MnMoO 4 CSNAs//AC ASCs is attributed to its enhanced surface area, abundant electroactive sites, facile electrolyte infiltration into the 3D NiCo 2 O 4 @MnMnO 4 nanoarrays and fast electron and ion transport path.

Effect of dietary supplementation with white button mushrooms on host resistance to influenza infection and immune function in mice

USDA-ARS?s Scientific Manuscript database

Previously we showed that mice fed white button mushrooms (WBM) had enhanced immune functions known to help the body’s antiviral defense. In this study, we tested if WBM could afford protection against viral infection. Young (4-mo) and old (22-mo) C57BL/6 mice were fed a diet containing 0, 2 per cen...

Type of Primary Nb₅Si₃ and Precipitation of Nbss in αNb₅Si₃ in a Nb-8.3Ti-21.1Si-5.4Mo-4W-0.7Hf (at.%) Near Eutectic Nb-Silicide-Based Alloy.

PubMed

McCaughey, Conor; Tsakiropoulos, Panos

2018-06-07

The Nb-silicide-based alloy of near eutectic composition (at.%) Nb-21.1Si-8.3Ti-5.4Mo-4W-0.7Hf (alloy CM1) was studied in the cast and heat-treated (1500 °C/100 h) conditions. The alloy was produced in the form of buttons and bars using three different methods, namely arc-melting, arc-melting and suction casting, and optical floating zone (OFZ) melting. In the former two cases the alloy solidified in water-cooled copper crucibles. Buttons and suction-cast bars of different size, respectively of 10 g and 600 g weight and 6 mm and 8 mm diameter, were produced. The OFZ bars were grown at three different growth rates of 12, 60 and 150 mm/h. It was confirmed that the type of Nb₅Si₃ formed in the cast microstructures depended on the solidification conditions. The primary phase in the alloy CM1 was the βNb₅Si₃. The transformation of βNb₅Si₃ to αNb₅Si₃ had occurred in the as cast large size button and the OFZ bars grown at the three different growth rates, and after the heat treatment of the small size button and the suction-cast bars of the alloy. This transformation was accompanied by subgrain formation in Nb₅Si₃ and the precipitation of Nb ss in the large size as cast button and only by the precipitation of Nb ss in the cast OFZ bars. Subgrains and precipitation of Nb ss in αNb₅Si₃ was observed in the small size button and suction-cast bars after the heat treatment. Subgrains formed in αNb₅Si₃ after the heat treatment of the OFZ bars. The partitioning of solutes and in particular of Mo and Ti was key to this phase transformation. Subgrain formation was not necessary for precipitation of Nb ss in αNb₅Si₃, but the partitioning of solutes was essential for this precipitation.

Biomechanics of the Proximal Radius Following Drilling of the Bicipital Tuberosity to Mimic Cortical Button Distal Biceps Repair Technique.

PubMed

Oak, Nikhil R; Lien, John R; Brunfeldt, Alexander; Lawton, Jeffrey N

2018-05-01

A fracture through the proximal radius is a theoretical concern after cortical button distal biceps fixation in an active patient. The permanent, nonossified cortical defect and medullary tunnel is at risk during a fall eliciting rotational and compressive forces. We hypothesized that during simulated torsion and compression, in comparison with unaltered specimens, the cortical button distal biceps repair model would have decreased torsional and compressive strength and would fracture in the vicinity of the bicipital tuberosity bone tunnel. Sixteen fourth-generation composite radius Sawbones models were used in this controlled laboratory study. A bone tunnel was created through the bicipital tuberosity to mimic the exact bone tunnel, 8 mm near cortex and 3.2 mm far cortex, made for the BicepsButton distal biceps tendon repair. The radius was then prepared and mounted on either a torsional or compression testing device and compared with undrilled control specimens. Compression tests resulted in average failure loads of 9015.2 N in controls versus 8253.25 N in drilled specimens ( P = .074). Torsional testing resulted in an average failure torque of 27.3 Nm in controls and 19.3 Nm in drilled specimens ( P = .024). Average fracture angle was 35.1° in controls versus 21.1° in drilled. Gross fracture patterns were similar in compression testing; however, in torsional testing all fractures occurred through the bone tunnel in the drilled group. There are weaknesses in the vicinity of the bone tunnel in the proximal radius during biomechanical stress testing which may not be clinically relevant in nature. In cortical button fixation, distal biceps repairs creates a permanent, nonossified cortical defect with tendon interposed in the bone tunnel, which can alter the biomechanical properties of the proximal radius during compressive and torsional loading.

Field comparison of three inhalable samplers (IOM, PGP-GSP 3.5 and Button) for welding fumes.

PubMed

Zugasti, Agurtzane; Montes, Natividad; Rojo, José M; Quintana, M José

2012-02-01

Inhalable sampler efficiency depends on the aerodynamic size of the airborne particles to be sampled and the wind speed. The aim of this study was to compare the behaviour of three personal inhalable samplers for welding fumes generated by Manual Metal Arc (MMA) and Metal Active Gas (MAG) processes. The selected samplers were the ones available in Spain when the study began: IOM, PGP-GSP 3.5 (GSP) and Button. Sampling was carried out in a welding training center that provided a homogeneous workplace environment. The static sampling assembly used allowed the placement of 12 samplers and 2 cascade impactors simultaneously. 183 samples were collected throughout 2009 and 2010. The range of welding fumes' mass concentrations was from 2 mg m(-3) to 5 mg m(-3). The pooled variation coefficients for the three inhalable samplers were less than or equal to 3.0%. Welding particle size distribution was characterized by a bimodal log-normal distribution, with MMADs of 0.7 μm and 8.2 μm. For these welding aerosols, the Button and the GSP samplers showed a similar performance (P = 0.598). The mean mass concentration ratio was 1.00 ± 0.01. The IOM sampler showed a different performance (P < 0.001). The mean mass concentration ratios were 0.90 ± 0.01 for Button/IOM and 0.92 ± 0.02 for GSP/IOM. This information is useful to consider the measurements accomplished by the IOM, GSP or Button samplers together, in order to assess the exposure at workplaces over time or to study exposure levels in a specific industrial activity, as welding operations.

Anterior capsulotomy with an ultrashort-pulse laser.

PubMed

Tackman, Ramon Naranjo; Kuri, Jorge Villar; Nichamin, Louis D Skip; Edwards, Keith

2011-05-01

To assess the precision of laser anterior capsulotomy compared with that of manual continuous curvilinear capsulorhexis (CCC). Asociación Para Evitar La Ceguera en México IAP, Hospital Dr. Luis Sánchez Bulnes, Mexico City, Mexico. Nonrandomized single-center clinical trial. In patients presenting for cataract surgery, the LensAR Laser System was used to create a laser anterior capsulotomy of the surgeon's desired size. Capsule buttons were retrieved and measured and then compared with buttons retrieved from eyes having a manually torn CCC. Deviation from the intended diameter and the regularity of shape were assessed. When removing the capsule buttons at the start of surgery, the surgeon rated the ease of removal on a scale of 1 to 10 (1 = required manual capsulorhexis around the whole diameter; 10 = button free floating or required no manual detachment from remaining capsule during removal). The mean deviation from the intended diameter was 0.16 mm ± 0.17 (SD) for laser anterior capsulotomy and 0.42 ± 0.54 mm for CCC (P=.03). The mean absolute deviation from the intended diameter was 0.20 ± 0.12 mm and 0.49 ± 0.47 mm, respectively (P=.003). The mean of the average squared residuals was 0.01 ± 0.03 and 0.02 ± 0.04, respectively (P=.09). The median rating of the ease of removal was 9 (range 5 to 10). Laser anterior capsulotomy created a more precise capsule opening than CCC, and the buttons created by the laser procedure were easy to remove at the beginning of cataract surgery. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Low-Temperature Fabrication of Robust, Transparent, and Flexible Thin-Film Transistors with a Nanolaminated Insulator.

PubMed

Kwon, Jeong Hyun; Park, Junhong; Lee, Myung Keun; Park, Jeong Woo; Jeon, Yongmin; Shin, Jeong Bin; Nam, Minwoo; Kim, Choong-Ki; Choi, Yang-Kyu; Choi, Kyung Cheol

2018-05-09

The lack of reliable, transparent, and flexible electrodes and insulators for applications in thin-film transistors (TFTs) makes it difficult to commercialize transparent, flexible TFTs (TF-TFTs). More specifically, conventional high process temperatures and the brittleness of these elements have been hurdles in developing flexible substrates vulnerable to heat. Here, we propose electrode and insulator fabrication techniques considering process temperature, transmittance, flexibility, and environmental stability. A transparent and flexible indium tin oxide (ITO)/Ag/ITO (IAI) electrode and an Al 2 O 3 /MgO (AM)-laminated insulator were optimized at the low temperature of 70 °C for the fabrication of TF-TFTs on a polyethylene terephthalate (PET) substrate. The optimized IAI electrode with a sheet resistance of 7 Ω/sq exhibited the luminous transmittance of 85.17% and maintained its electrical conductivity after exposure to damp heat conditions because of an environmentally stable ITO capping layer. In addition, the electrical conductivity of IAI was maintained after 10 000 bending cycles with a tensile strain of 3% because of the ductile Ag film. In the metal/insulator/metal structure, the insulating and mechanical properties of the optimized AM-laminated film deposited at 70 °C were significantly improved because of the highly dense nanolaminate system, compared to those of the Al 2 O 3 film deposited at 70 °C. In addition, the amorphous indium-gallium-zinc oxide (a-IGZO) was used as the active channel for TF-TFTs because of its excellent chemical stability. In the environmental stability test, the ITO, a-IGZO, and AM-laminated films showed the excellent environmental stability. Therefore, our IGZO-based TFT with IAI electrodes and the 70 °C AM-laminated insulator was fabricated to evaluate robustness, transparency, flexibility, and process temperature, resulting in transfer characteristics comparable to those of an IGZO-based TFT with a 150 °C Al 2 O 3 insulator.

Adhesion testing device

NASA Technical Reports Server (NTRS)

LaPeyronnie, Glenn M. (Inventor); Huff, Charles M. (Inventor)

2010-01-01

The present invention provides a testing apparatus and method for testing the adhesion of a coating to a surface. The invention also includes an improved testing button or dolly for use with the testing apparatus and a self aligning button hook or dolly interface on the testing apparatus. According to preferred forms, the apparatus and method of the present invention are simple, portable, battery operated rugged, and inexpensive to manufacture and use, are readily adaptable to a wide variety of uses, and provide effective and accurate testing results. The device includes a linear actuator driven by an electric motor coupled to the actuator through a gearbox and a rotatable shaft. The electronics for the device are contained in the head section of the device. At the contact end of the device, is positioned a self aligning button hook, attached below the load cell located on the actuator shaft.

Connected cane: Tactile button input for controlling gestures of iOS voiceover embedded in a white cane.

PubMed

Batterman, Jared M; Martin, Vincent F; Yeung, Derek; Walker, Bruce N

2018-01-01

Accessibility of assistive consumer devices is an emerging research area with potential to benefit both users with and without visual impairments. In this article, we discuss the research and evaluation of using a tactile button interface to control an iOS device's native VoiceOver Gesture navigations (Apple Accessibility, 2014). This research effort identified potential safety and accessibility issues for users trying to interact and control their touchscreen mobile iOS devices while traveling independently. Furthermore, this article discusses the participatory design process in creating a solution that aims to solve issues in utilizing a tactile button interface in a novel device. The overall goal of this study is to enable visually impaired white cane users to access their mobile iOS device's capabilities navigation aids more safely and efficiently on the go.

°Enhancing High Temperature Anode Performance with 2° Anchoring Phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Robert A.; Sofie, Stephen W.; Amendola, Roberta

2015-10-01

Project accomplishments included developing and optimizing strength testing of aluminum titanate (ALT)-doped Ni-YSZ materials and identified the dopant levels that optimized mechanical strength and enhanced electrochemical performance. We also optimized our ability to fabricate electrolyte supported button cells with anodes consisting of powders provided by Fuel Cell Energy. In several instances, those anodes were infiltrated with ALT and tested with hydrogen for 30 hours at 800°C at an applied potential of 0.4 V. Our research activities were focused in three areas: 1) mechanical strength testing on as prepared and reducced nickel-YSZ structures that were either free of a dopant ormore » prepared by mechanically mixing in ALT at various weight percents (up to 10 wt%); 2) 24-hour electrochemical testing of electroylte supported cells having anodes made from Ni/YSZ and Ni/YSZ/ALT anodes with specific attention focused on modeling degradation rates; and 3) operando EIS and optical testing of both in-house fabricated devices as well as membrane electrode assemblies that were acquired from commercial vendors.« less

A novel cobalt-free layered GdBaFe 2O 5+ δ cathode for proton conducting solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Ding, Hanping; Xue, Xingjian

While cobalt-containing perovskite-type cathode materials facilitate the activation of oxygen reduction, they also suffer from problems like poor chemical stability in CO 2 and high thermal expansion coefficients. In this research, a cobalt-free layered GdBaFe 2O 5+ δ (GBF) perovskite was developed as a cathode material for protonic ceramic membrane fuel cells (PCMFCs) based on proton conducting electrolyte of stable BaZr 0.1Ce 0.7Y 0.2O 3- δ (BZCY7). The button cells of Ni-BZCY7|BZCY7|GBF were fabricated and characterized using complex impedance technique from 600 to 700 °C. An open-circuit potential of 1.007 V, maximum power density of 417 mW cm -2, and a low electrode polarization resistance of 0.18 Ω cm 2 were achieved at 700 °C. The results indicate that layered GBF perovskite is a good candidate for cobalt-free cathode material, while the developed Ni-BZCY7|BZCY7|GBF cell is a promising functional material system for solid oxide fuel cells.

Is the Go/No-Go Lexical Decision Task Preferable to the Yes/No Task with Developing Readers?

ERIC Educational Resources Information Center

Moret-Tatay, Carmen; Perea, Manuel

2011-01-01

The lexical decision task is probably the most common laboratory visual word identification task together with the naming task. In the usual setup, participants need to press the "yes" button when the stimulus is a word and the "no" button when the stimulus is not a word. A number of studies have employed this task with developing readers;…

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCracken, Brewster

Through funding from the Department of Energy’s Electricity Delivery and Reliability Office, Pecan Street Inc., in partnership with Austin Energy and Oncor, developed and tested third- party data access platforms and services for Green Button offerings and for other home energy use data providers. As more utilities seek to offer Green Button-compliant data to their customers, the question continually arises of how this data can be used to help customers better manage their energy use.

Hot-Button Issues for Teachers: What Every Educator Needs to Know About Leadership, Testing, Textbooks, Vouchers, and More

ERIC Educational Resources Information Center

Vairo, Philip D.; Marcus, Sheldon; Weiner, Max

2007-01-01

One of the tragedies of American education is that so many teachers do not understand or are unaware of educational issues and how they impact on their profession. There is a gap between teacher perceptions and reality and this book is a first step in closing that gap. Hot-Button Issues for Teachers is a timely, comprehensive book that addresses…

Supplemental Archeological Investigations of Lower Bayou Teche, St. Mary Parish, Louisiana

DTIC Science & Technology

1991-08-01

Ruler end (brass)1 ____ Buckle 1__________ Brass and inlaid shell button 1____ Chain 2 71 Cosmetic cap - gild brass inlaid with shell 1I____ 185...Molded stemnware fragment ____ _____ _____ Unidentified ______ ______1 Perfume/ Cosmetic Bottle Fragment Milk glass 2 Melted Glass Aqua1 Unidentified...major portion of the recovery (n = 122). Other metal artifacts included 2 safety pins, 1 cosmetic cap made of gilt brass inlaid with shell, 3 buttons

Allelopathic effects of the aqueous extract of the leaf and seed of Leucaena leucocephala on three selected weed species

NASA Astrophysics Data System (ADS)

Ishak, Muhamad Safwan; Sahid, Ismail

2014-09-01

A laboratory experiment was conducted to study the allelopathic effects of the aqueous extract of the leaf and seed of Leucaena leucocephala. The aqueous extracts were individually tested on three selected weed species, namely goatweed (Ageratum conyzoides), coat buttons (Tridax procumbens) and lilac tasselflower (Emilia sonchifolia). The allelopathic effects of the leaf and seed extracts on germination, shoot length, root length and fresh weight of each of the selected weed species were determined. Germination of goatweed, coat buttons and lilac tasselflower were inhibited by the aqueous extracts of both the leaf and seed of L. leucocephala and was concentration dependent. Different concentrations of the aqueous extracts showed various germination patterns on the selected weeds species. Seedling length and fresh weight of goatweed, coat buttons and lilac tasselflower were reduced in response to respective increasing concentrations of the seed extracts. Maximum inhibition by the aqueous seed extract was observed more on the root rather than the shoot growth. The aqueous seed extract at T3 concentration reduced root length of goatweed, coat buttons and lilac tasselflower by 95%, 86% and 91% (of the control) respectively. The aqueous seed extract showed greater inhibitory effects than that of the aqueous leaf extract.

Distinct dynamical patterns that distinguish willed and forced actions.

PubMed

Garcia Dominguez, Luis; Kostelecki, Wojciech; Wennberg, Richard; Perez Velazquez, Jose L

2011-03-01

The neural pathways for generating willed actions have been increasingly investigated since the famous pioneering work by Benjamin Libet on the nature of free will. To better understand what differentiates the brain states underlying willed and forced behaviours, we performed a study of chosen and forced actions over a binary choice scenario. Magnetoencephalography recordings were obtained from six subjects during a simple task in which the subject presses a button with the left or right finger in response to a cue that either (1) specifies the finger with which the button should be pressed or (2) instructs the subject to press a button with a finger of their own choosing. Three independent analyses were performed to investigate the dynamical patterns of neural activity supporting willed and forced behaviours during the preparatory period preceding a button press. Each analysis offered similar findings in the temporal and spatial domains and in particular, a high accuracy in the classification of single trials was obtained around 200 ms after cue presentation with an overall average of 82%. During this period, the majority of the discriminatory power comes from differential neural processes observed bilaterally in the parietal lobes, as well as some differences in occipital and temporal lobes, suggesting a contribution of these regions to willed and forced behaviours.

Double-button Fixation System for Management of Acute Acromioclavicular Joint Dislocation

PubMed Central

Torkaman, Ali; Bagherifard, Abolfazl; Mokhatri, Tahmineh; Haghighi, Mohammad Hossein Shabanpour; Monshizadeh, Siamak; Taraz, Hamid; Hasanvand, Amin

2016-01-01

Background: Surgical treatments for acromioclavicular (AC) joint dislocation present with some complications. The present study was designed to evaluate the double-button fixation system in the management of acute acromioclavicular joint dislocation. Methods: This cross sectional study, done between February 2011 to June 2014, consisted of 28 patients who underwent surgical management by the double-button fixation system for acute AC joint dislocation. Age, sex, injury mechanism, dominant hand, side with injury, length of follow up, time before surgery, shoulder and hand (DASH), constant and visual analogue scale (VAS) scores, and all complications of the cases during the follow up were recorded. Results: The mean age of patients was 33.23±6.7 years. Twenty four patients (85.71%) were male and four (14.28%) were female. The significant differences were observed between pre-operation VAS, constant shoulder scores and post-operation measurements. There were not any significant differences between right and left coracoclavicular, but two cases of heterotrophic ossifications were recorded. The mean follow-up time was 16.17±4.38 months. Conclusion: According to the results, the double-button fixation system for management of acute acromioclavicular joint dislocation has suitable results and minimal damage to the soft tissues surrounding the coracoclavicular ligaments. PMID:26894217

Subthalamic nucleus involvement in executive functions with increased cognitive load: a subthalamic nucleus and anterior cingulate cortex depth recording study.

PubMed

Aulická, Stefania Rusnáková; Jurák, Pavel; Chládek, Jan; Daniel, Pavel; Halámek, Josef; Baláž, Marek; Bočková, Martina; Chrastina, Jan; Rektor, Ivan

2014-10-01

We studied the appearance of broadband oscillatory changes (ranging 2-45 Hz) induced by a cognitive task with two levels of complexity. The event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and in the anterior cingulate cortex (ACC) were evaluated in an executive function test. Four epilepsy surgery candidates with intracerebral electrodes implanted in the ACC and three Parkinson's disease patients with externalized deep brain stimulation electrodes implanted in the STN participated in the study. A Flanker test (FT) with visual stimuli (arrows) was performed. Subjects reacted to four types of stimuli presented on the monitor by pushing the right or left button: congruent arrows to the right or left side (simple task) and incongruent arrows to the right or left side (more difficult complex task). We explored the activation of STN and the activation of the ACC while processing the FT. Both conditions, i.e. congruent and incongruent, induced oscillatory changes in the ACC and also STN with significantly higher activation during incongruent trial. At variance with the ACC, in the STN not only the ERD beta but also the ERD alpha activity was significantly more activated by the incongruent condition. In line with our earlier studies, the STN appears to be involved in activities linked with increased cognitive load. The specificity and complexity of task-related activation of the STN might indicate the involvement of the STN in processes controlling human behaviour, e.g. in the selection and inhibition of competing alternatives.

Arthroscopic Latarjet Techniques: Graft and Fixation Positioning Assessed With 2-Dimensional Computed Tomography Is Not Equivalent With Standard Open Technique.

PubMed

Neyton, Lionel; Barth, Johannes; Nourissat, Geoffroy; Métais, Pierre; Boileau, Pascal; Walch, Gilles; Lafosse, Laurent

2018-05-19

To analyze graft and fixation (screw and EndoButton) positioning after the arthroscopic Latarjet technique with 2-dimensional computed tomography (CT) and to compare it with the open technique. We performed a retrospective multicenter study (March 2013 to June 2014). The inclusion criteria included patients with recurrent anterior instability treated with the Latarjet procedure. The exclusion criterion was the absence of a postoperative CT scan. The positions of the hardware, the positions of the grafts in the axial and sagittal planes, and the dispersion of values (variability) were compared. The study included 208 patients (79 treated with open technique, 87 treated with arthroscopic Latarjet technique with screw fixation [arthro-screw], and 42 treated with arthroscopic Latarjet technique with EndoButton fixation [arthro-EndoButton]). The angulation of the screws was different in the open group versus the arthro-screw group (superior, 10.3° ± 0.7° vs 16.9° ± 1.0° [P < .001]; inferior, 10.3° ± 0.8° vs 15.7° ± 0.9° [P < .0001]). The angulation of the EndoButtons was 5.7° ± 0.5°; this was different from that of open inferior screws (P = .003). In the axial plane (level of equator), the arthroscopic techniques resulted in lateral positions (arthro-screw, 1.5 ± 0.3 mm lateral [P < .001]; arthro-EndoButton, 0 ± 0.3 mm lateral [P < .0001]) versus the open technique (0.9 ± 0.2 mm medial). At the level of 25% of the glenoid height, the arthroscopic techniques resulted in lateral positions (arthro-screw, 0.3 ± 0.3 mm lateral [P < .001]); (arthro-EndoButton, 0.7 ± 0.3 mm lateral [P < .0001]) versus the open technique (1.0 ± 0.2 mm medial). Higher variability was observed in the arthro-screw group. In the sagittal plane, the arthro-screw technique resulted in higher positions (55% ± 3% of graft below equator) and the arthro-EndoButton technique resulted in lower positions (82% ± 3%, P < .0001) versus the open technique (71% ± 2%). Variability was not different. This study shows that the position of the fixation devices and position of the bone graft with the arthroscopic techniques are statistically significantly different from those with the open technique with 2-dimensional CT assessment. In the sagittal plane, the arthro-screw technique provides the highest positions, and the arthro-EndoButton technique, the lowest. Overall, the mean position of the bone block with the open Latarjet technique in the axial plane is slightly medial to the joint line, as recommended. Conversely, with the arthroscopic techniques, the bone grafts are more lateral with a slight overhang. The main differences are observed in the dispersion of the values (more extreme positions) with the arthro-screw technique, given the acknowledged limitations. Despite the statistical significance, the clinical significance of these differences is yet unknown. Level III, retrospective comparative study. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A Study of Selected Problems in Armor Operations

DTIC Science & Technology

1978-11-01

of external environmental cond~tions on the internal environment of a buttoned-up tank. Another effort was a study of problems in escape and...Test site configuration: Study II ......... ... IV-16 FIG. IVT4. Mean time to lay on target .... ........ .... IV-20 TABLES Chapter III Table III-I...L., and Ton, W. H. Study of the Psychological (and Associated Physiological) Effjcts on a Tank Crew Resulting From Being Buttoned Up, ARI Research

Consortium Requirements Engineering Guidebook

DTIC Science & Technology

1993-12-01

re- quirements among developers or contractors, acquisition managers, and users. A CoRE specification serves as both the test -to and design-to...that are used for the following purposes: (1) the button labeled SELF TEST allows the operator to check the FLMS’s output hardware while the system is...shut down; and (2) the button labeled RESET allows the system to be brought back into normal operation following a shutdown or testing as long as the

An ergonomics study of thumb movements on smartphone touch screen.

PubMed

Xiong, Jinghong; Muraki, Satoshi

2014-01-01

This study investigated the relationships between thumb muscle activity and thumb operating tasks on a smartphone touch screen with one-hand posture. Six muscles in the right thumb and forearm were targeted in this study, namely adductor pollicis, flexor pollicis brevis, abductor pollicis brevis (APB), abductor pollicis longus, first dorsal interosseous (FDI) and extensor digitorum. The performance measures showed that the thumb developed fatigue rapidly when tapping on smaller buttons (diameter: 9 mm compared with 3 mm), and moved more slowly in flexion-extension than in adduction-abduction orientation. Meanwhile, the electromyography and perceived exertion values of FDI significantly increased in small button and flexion-extension tasks, while those of APB were greater in the adduction-abduction task. This study reveals that muscle effort among thumb muscles on a touch screen smartphone varies according to the task, and suggests that the use of small touch buttons should be minimised for better thumb performance.

A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michnoff R.; Biscardi, C.; Cerniglia, P.

2012-04-15

A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scannermore » assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.« less

Archeological Survey and Testing in the Holy Cross Historic District, New Orleans, Louisiana. Volume 2

DTIC Science & Technology

1992-02-01

467 Table 4 Personal Items from Shovel Tests, 160R130. SURF SURF SURF N15 N5 NO NO $5 S5 1 2 3 W20 El5 E20 W10 E20 EO Bone button, Type B-5 Ceramic...Table 4 . Personal Items from Shovel Tests, 160R130. S15 S20 S20 S25 S25 S30 S30 S30 S32.5 E5 E35 E20 E50 E25 E50 E35 E20 E35 Bone button, Type B-5...1 1 1 7 1 471 Table 4 Personal Items from Shovel Tests, 160R130. S30 S34 S35 S45 S50 TOTAL El0 E35 E30 E30 E55 Bone button, Type B-5 1 1 Ceramic

The effect of target materials on the propagation of atmospheric-pressure plasma jets

NASA Astrophysics Data System (ADS)

Ji, Longfei; Yan, Wen; Xia, Yang; Liu, Dongping

2018-05-01

The current study is focused on the effect of target materials (quartz plate, copper sheet, and quartz plate with a grounded copper sheet on the back) on the propagation of atmospheric-pressure helium plasma jets. The dynamics of ionization waves (IWs) and the relative amount of reactive oxygen species (OH and O) in the IW front were compared by using spatial and temporal images and relative optical emission spectroscopy. Our measurements show that the targets can significantly affect the propagation and intensity of the IWs. In addition, strong OH emission lines were detected when the IWs impinged upon the damp surface. Numerical simulations have been carried out to explain the experimental observation. The propagation velocity of IWs predicted by the simulation was in good agreement with the experimental results. Simulation results suggest that the density and velocity of IWs mainly depend on the electric field between the high voltage electrode tip and the target. Analysis indicates that the targets could change the electric field distribution between the high voltage electrode and targets and thus affect the dynamics and the density of the IWs, the generation of reactive oxygen species, and the corresponding sterilization efficiency.

Biomechanical evaluation of a transtibial pull-out meniscal root repair: challenging the bungee effect.

PubMed

Cerminara, Anthony J; LaPrade, Christopher M; Smith, Sean D; Ellman, Michael B; Wijdicks, Coen A; LaPrade, Robert F

2014-12-01

A common treatment for posterior meniscal root tears is transtibial pull-out repair, which has been biomechanically reported to restore tibiofemoral contact mechanics to those of the intact knee. Biomechanical data suggest that there is significant displacement of the repaired meniscal root with cyclic loading, which may be responsible for the poor healing and meniscal extrusion demonstrated in some clinical studies. The purpose of this study was to quantify the time-zero displacement of the posterior meniscal root in response to cyclic loading after transtibial pull-out repair and to quantify the individual contributions to displacement of the following: (1) suture elongation, (2) button-bone interface, and (3) meniscus-suture interface. The meniscus-suture interface was hypothesized to result in significantly more displacement than the button-bone interface or suture elongation. Descriptive laboratory study. Transtibial pull-out repair of the posterior medial meniscal root was performed in 6 porcine knees, and cyclic displacement was measured using a loading protocol representative of postoperative rehabilitation. Displacement from (1) suture elongation, (2) the button-bone interface, and (3) the meniscus-suture interface was determined by cyclically loading 6 specimens for each construct using the same loading protocol to determine the contribution of each component to the overall displacement of the repair construct. After 1000 cycles, the repair construct displaced by a mean of 3.28 mm (95% CI, 2.07-4.49). The meniscus-suture component (mean, 2.52 mm; 95% CI, 2.21-2.83) displaced significantly more than the button-bone component (mean, 0.90 mm; 95% CI, 0.64-1.15; P = .006) and suture elongation component (mean, 0.71 mm; 95% CI, 0.36-1.06; P = .006) after 1000 cycles. Displacement of the button-bone and suture elongation components was not significantly different after 1000 cycles (P = .720). There was substantial displacement of the posterior medial meniscal root repaired with the transtibial pull-out technique under a cyclic loading protocol simulating postoperative rehabilitation. The meniscus-suture interface contributed to significantly more displacement than the button-bone interface and suture elongation in the transtibial pull-out repair construct. The results provide a framework for optimizing the transtibial pull-out repair technique. Future studies should focus on improving suture fixation strength within the meniscus-suture interface. © 2014 The Author(s).

Collaborative Systems and Multi-user Interfaces: Computer-based Tools for Cooperative Problem Solving

DTIC Science & Technology

1986-10-31

Reference Card Given to Participants) Cognoter Reference Select = LeftButton Menu = MiddleButton TitleBar menu for tool operations Item menu for item...collaborative tools and their uses, the Colab system and the Cognoter presentation tool were implemented and used for both real and posed idea organization...tasks. To test the system design and its effect on structured problem-solving, many early Colab/ Cognoter meetings were monitored and a series of

Evaluation of tooth-click triggering and speech recognition in assistive technology for computer access.

PubMed

Simpson, Tyler; Gauthier, Michel; Prochazka, Arthur

2010-02-01

Computer access can play an important role in employment and leisure activities following spinal cord injury. The authors' prior work has shown that a tooth-click detecting device, when paired with an optical head mouse, may be used by people with tetraplegia for controlling cursor movement and mouse button clicks. To compare the efficacy of tooth clicks to speech recognition and that of an optical head mouse to a gyrometer head mouse for cursor and mouse button control of a computer. Six able-bodied and 3 tetraplegic subjects used the devices listed above to produce cursor movements and mouse clicks in response to a series of prompts displayed on a computer. The time taken to move to and click on each target was recorded. The use of tooth clicks in combination with either an optical head mouse or a gyrometer head mouse can provide hands-free cursor movement and mouse button control at a speed of up to 22% of that of a standard mouse. Tooth clicks were significantly faster at generating mouse button clicks than speech recognition when paired with either type of head mouse device. Tooth-click detection performed better than speech recognition when paired with both the optical head mouse and the gyrometer head mouse. Such a system may improve computer access for people with tetraplegia.

Inclusion Behavior During the Electron Beam Button Melting Test

NASA Astrophysics Data System (ADS)

Bellot, J. P.; Defay, B.; Jourdan, J.; Chapelle, P.; Jardy, A.

2012-10-01

The high mechanical performance of alloys developed for the manufacture of turbine disks depend upon the size and the number density of the inclusions. The electron beam button method has been practiced since the 1980s as a technique to quantify the cleanliness of the superalloys as well as to identify the nature and the size of the inclusions. The technique involves melting the sample into a hemispherical water-cooled crucible and the low density inclusions (mainly oxides) are concentrated by a combination of Marangoni and buoyancy forces into an area at the top surface of the button referred to as the raft. We have experimentally studied the behavior of oxide inclusions in special steels using both high definition video and infrared cameras. We have observed the inversion of the Marangoni effect due to the presence of sulfur, which leads to a positive temperature coefficient of the surface tension. A mathematical modeling has been carried out to simulate the turbulent fluid flow associated with the temperature field in the metallic pool of the button. The surface temperature profile has been successfully compared with the measured data. A post-processor numerical tool calculates the inclusion trajectories taking into account the turbulent fluctuation velocity by a stochastic approach. Hence, the behavior of a population of inclusions has been statistically studied, and the dependence of the capture efficiency on the inclusion size has been analyzed.

A Geant4 evaluation of the Hornyak button and two candidate detectors for the TREAT hodoscope

NASA Astrophysics Data System (ADS)

Fu, Wenkai; Ghosh, Priyarshini; Harrison, Mark J.; McGregor, Douglas S.; Roberts, Jeremy A.

2018-05-01

The performance of traditional Hornyak buttons and two proposed variants for fast-neutron hodoscope applications was evaluated using Geant4. The Hornyak button is a ZnS(Ag)-based device previously deployed at the Idaho National Laboratory's TRansient REActor Test Facility (better known as TREAT) for monitoring fast neutrons emitted during pulsing of fissile fuel samples. Past use of these devices relied on pulse-shape discrimination to reduce the significant levels of background Cherenkov radiation. Proposed are two simple designs that reduce the overall light guide mass (here, polymethyl methacrylate or PMMA), employ silicon photomultipliers (SiPMs), and can be operated using pulse-height discrimination alone to eliminate background noise to acceptable levels. Geant4 was first used to model a traditional Hornyak button, and for assumed, hodoscope-like conditions, an intrinsic efficiency of 0.35% for mono-directional fission neutrons was predicted. The predicted efficiency is in reasonably good agreement with experimental data from the literature and, hence, served to validate the physics models and approximations employed. Geant4 models were then developed to optimize the materials and geometries of two alternatives to the Hornyak button, one based on a homogeneous mixture of ZnS(Ag) and PMMA, and one based on alternating layers of ZnS(Ag) and PMMA oriented perpendicular to the incident neutron beam. For the same radiation environment, optimized, 5-cm long (along the beam path) devices of the homogeneous and layered designs were predicted to have efficiencies of approximately 1.3% and 3.3%, respectively. For longer devices, i.e., lengths larger than 25 cm, these efficiencies were shown to peak at approximately 2.2% and 5.9%, respectively. Moreover, both designs were shown to discriminate Cherenkov noise intrinsically by using an appropriate pulse-height discriminator level, i.e., pulse-shape discrimination is not needed for these devices.

Correlation Between Corneal Button Size and Intraocular Pressure During Femtosecond Laser-Assisted Keratoplasty.

PubMed

Choi, Mihyun; Lee, Yong Eun; Whang, Woong-Joo; Yoo, Young-Sik; Na, Kyung-Sun; Joo, Choun-Ki

2016-03-01

To evaluate changes in intraocular pressure (IOP) in recipient and donor eyes during femtosecond laser-assisted keratoplasty (FLAK) and to assess for differences in the diameter of trephinated corneal buttons according to changes in pressure. Twenty porcine whole eyes (recipient model) and 20 porcine-corneoscleral rims (donor model) were prepared, and anterior chamber pressures were measured using a fiberoptic sensing device (Opsens, Quebec, Canada) during the femtosecond laser corneal cutting process. To determine the diameter of corneal buttons, 10 porcine whole eyes (recipient model) and 12 corneoscleral rims (donor model) of each baseline IOP were cut with the femtosecond laser programmed to the following pattern: "vertical side cut"; 1200 μm (depth), 8 mm (diameter). Digital photographs were obtained using microscopy and subsequently analyzed. The IOP (mean ± SD) for the recipient model was 10.2 (±0.9) mm Hg at baseline and ranged from 96.6 (±4.5) to ∼138.4 (±3.8) mm Hg during the corneal cutting process. This shows that the maximum IOP during FLAK increased 13.5 times compared with baseline. In the donor model, the mean pressure elevation from baseline artificial anterior chamber (AAC) pressure to corneal cutting was 15.8 (±5.4) mm Hg. This showed a positive correlation with baseline IOP [correlation coefficient (CC) = 0.827, P = 0.006]. As the baseline IOP in the recipient eye increased, trephinated corneal button size was reduced by up to 3.9% in diameter (CC = -0.945, P = 0.015). In addition, in donor eyes, the diameter was decreased by up to 11.7% as the baseline AAC pressure increased (CC = -0.934, P = 0.006). During the FLAK procedure, the IOP increases in both recipient and donor eyes. The diameter of the trephinated donor and recipient corneal buttons was decreased as the initial baseline IOP increased. Ophthalmic surgeons can determine the AAC pressure based on the baseline IOP in the recipient patient.

A Geant4 evaluation of the Hornyak button and two candidate detectors for the TREAT hodoscope

DOE PAGES

Fu, Wenkai; Ghosh, Priyarshini; Harrison, Mark; ...

2018-02-05

The performance of traditional Hornyak buttons and two proposed variants for fast-neutron hodoscope applications was evaluated using Geant4. The Hornyak button is a ZnS(Ag)-based device previously deployed at the Idaho National Laboratory's TRansient REActor Test Facility (better known as TREAT) for monitoring fast neutrons emitted during pulsing of fissile fuel samples. Past use of these devices relied on pulse-shape discrimination to reduce the significant levels of background Cherenkov radiation. Proposed are two simple designs that reduce the overall light guide mass (here, polymethyl methacrylate or PMMA), employ silicon photomultipliers (SiPMs), and can be operated using pulse-height discrimination alone to eliminatemore » background noise to acceptable levels. Geant4 was first used to model a traditional Hornyak button, and for assumed, hodoscope-like conditions, an intrinsic efficiency of 0.35% for mono-directional fission neutrons was predicted. The predicted efficiency is in reasonably good agreement with experimental data from the literature and, hence, served to validate the physics models and approximations employed. Geant4 models were then developed to optimize the materials and geometries of two alternatives to the Hornyak button, one based on a homogeneous mixture of ZnS(Ag) and PMMA, and one based on alternating layers of ZnS(Ag) and PMMA oriented perpendicular to the incident neutron beam. For the same radiation environment, optimized, 5-cm long (along the beam path) devices of the homogeneous and layered designs were predicted to have efficiencies of approximately 1.3% and 3.3%, respectively. For longer devices, i.e., lengths larger than 25 cm, these efficiencies were shown to peak at approximately 2.2% and 5.9%, respectively. Furthermore, both designs were shown to discriminate Cherenkov noise intrinsically by using an appropriate pulse-height discriminator level, i.e., pulse-shape discrimination is not needed for these devices.« less

Revision ulnar collateral ligament reconstruction using a suspension button fixation technique.

PubMed

Lee, Gregory H; Limpisvasti, Orr; Park, Maxwell C; McGarry, Michelle H; Yocum, Lewis A; Lee, Thay Q

2010-03-01

Revision ulnar collateral ligament reconstruction remains a challenging problem. The objective of this study was to biomechanically evaluate an ulnar collateral ligament reconstruction technique using a suspension button fixation technique that can be used even in the case of ulnar cortical bone loss. An ulnar suspension fixation technique for ulnar collateral ligament reconstruction can restore elbow kinematics and demonstrate failure strength comparable to that of currently available techniques. Controlled laboratory study. Nine pairs of cadaveric elbows were dissected free of soft tissue and potted. After simulating ulnar cortical bone loss, ulnar collateral ligament reconstruction was performed in 1 elbow of each pair using palmaris longus autograft and a 30-mm RetroButton suspended from the far (lateralmost) ulnar cortex. A docking technique was used for humeral fixation of the graft. Elbow valgus angle was quantified using a Microscribe 3DLX digitizer at multiple elbow flexion angles. Valgus angle was measured with the ulnar collateral ligament intact, transected, and reconstructed. In addition, load-to-failure testing was performed in 1 elbow of each pair. Release of the ulnar collateral ligament caused a significant increase in valgus angle at each flexion angle tested (P < .002). Reconstructed elbows demonstrated no significant differences in valgus angle from the intact elbow at all flexion angles tested. Load-to-failure tests showed that reconstructed elbows had an ultimate torque (10.3 + or - 5.7 N x m) significantly less than intact elbows (26.4 + or - 10.6 N x m) (P = .001). Ulnar collateral ligament reconstruction using a suspension button fixation technique reliably restored elbow kinematics to the intact state. Load-to-failure testing demonstrated comparable fixation strength to several historic controls of primary reconstruction techniques despite the simulated ulnar cortical bone loss. Ulnar collateral ligament reconstruction using a suspension button fixation technique can be considered in the case of ulnar cortical bone loss in a primary or revision setting.

Arthroscopically assisted reduction of acute acromioclavicular joint dislocation using a single double-button device: Medium-term clinical and radiological outcomes.

PubMed

Issa, S-P; Payan, C; Le Hanneur, M; Loriaut, P; Boyer, P

2018-02-01

Double-button devices for endoscopic management of acute acromioclavicular joint dislocation (ACJD) provide satisfactory short-term functional and radiological results. However, little exists in the literature regarding the long- and medium-term results of these implants, especially regarding the evolution of the acromioclavicular joint (ACJ). Satisfactory and steady long- and medium-term outcomes can be achieved in patients with acute ACJD undergoing endoscopically assisted ACJ repair using a single double-button device. A retrospective single-center study was conducted in patients with acute Rockwood III and IV ACJD treated endoscopically with a single double-button device from October 2008 to October 2010, allowing a minimum 5-year follow-up. Functional evaluation used Constant and Quick-DASH scores. Clinical evidence of dislocation recurrence was combined with bilateral Zanca views to assess coracoclavicular distance. Acromioclavicular osteoarthritis was evaluated on the Paxinos test and Zanca views. Nineteen of the 25 operated patients were seen at a mean 76.9±8.5 months' follow-up. Mean age was 34.4±8.3 years. Mean Constant and Quick-DASH scores were 96.2±5.1 and 0.9±1.6 points, respectively. Four patients had a recurrence of their initial dislocation, 3 of whom had positive Paxinos test, whereas the 15 patients without recurrence had a negative test (p=0.004). Five patients had radiological evidence of ACJ osteoarthritis: all 4 patients with recurrence and 1 without (p=0.001). Long- and medium-term radioclinical outcome of endoscopically assisted management of acute ACJD using a single double-button device seems to be satisfactory and steady over time. Recurrence of the initial dislocation appears to be related to onset of degenerative ACJ arthropathy. Therapeutic type IV-Retrospective case series. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Investigation of Optically Induced Avalanching in GaAs

DTIC Science & Technology

1989-06-01

by Bovino , et al 4 to increase the hold off voltage. The button switch design of Fig. 4c has been used by several researchers5 ’ 7 to obtain the...ul Long flashover palh Figure 3b. 434 Optical Jlatlern a. Mourou Switch b. Bovino Switch c. Button Switch Figure 4. Photoconductive Switches...Technology and Devices Laboratory, ERADCOM (by L. Bovino , et. all) 4 • The deposition recipe for the contacts is 1) 50 ANi (provides contact to GaAs

Design and Implementation of an Operations Module for the ARGOS paperless Ship System

DTIC Science & Technology

1989-06-01

A. OPERATIONS STACK SCRIPTS SCRIPTS FOR STACK: operations * BACKGROUND #1: Operations * on openStack hide message box show menuBar pass openStack end... openStack ** CARD #1, BUTTON #1: Up ***** on mouseUp visual effect zoom out go to card id 10931 of stack argos end mouseUp ** CARD #1, BUTTON #2...STACK SCRIPTS SCRIPTS FOR STACK: Reports ** BACKGROUND #1: Operations * on openStack hie message box show menuBar pass openStack end openStack ** CARD #1

Sealing Penetrating Eye Injuries Using Photoactivated Bonding

DTIC Science & Technology

2010-09-30

on  corneal tissue. To evaluate inflammation all 15 rabbits will be euthanized with  phenobarbital . The  10 corneoscleral button of tissue will be...will be euthanized with  phenobarbital . The  corneoscleral button of tissue will be removed and divided into portions for paraffin and frozen sections

Study of Psychological (and Associated Physiological) Effects on a Tank Crew Resulting from Being Buttoned Up

DTIC Science & Technology

1976-10-01

should he made for either ixiternal storage or a means of voiding the urinal in a storage container in the compartment’. Development of-Adequate...upper temperature ranges fu- critical components of the M60 tank under desert storage and operational conditions. He found that the Wet Bulb Globe...five-gallon cans on the outside turret bustle racks. If buttoned-up operations for extended periods of time are envisioned, a built-in water storage

Energy Saving in Electric Lighting for the United States Army.

DTIC Science & Technology

1979-10-05

these reasons. Avoid devices such as power saving buttons which are to be placed in the sockets of incandescent bulbs. They are merely half-wave...using the button or a long-life bulb. Another device to avoid is the pulse or transient suppressor. This device, essentially a voltage clipper...arranged In a geo- metric pattern. It is used to shield a lamp from Lumen: A unit of light output from a lamp. view at certain angles to avoid glare from

Far Forward Life Support System (FFLSS) Phase II

DTIC Science & Technology

2001-05-01

button will clear audible, flashing , or constant red alarms. Pushing the Config button drops down to the Level 2 menu (bottom line of Figure 8). In...disabled. Again, with testing this audible noise can be disabled. The visual flashing or constant red cannot be disabled. Pushing Return goes back to Level...Calling PLOTPIXEL( x ,y) and PLOTLINE(xl,x2,yl,y2) is as simple as pushing the appropriate bytes (unsigned integers) onto the stack and jumping to the

Novel Nano-particle, Temperature-Independent Damping System: Basic Science and Applications

DTIC Science & Technology

2009-12-31

based impact damping or a fluid -based viscous damping system, and/d =fn in a frictional damping systems.. The increase in frequency is caused by either...to provide temperature independent damping. While the damping performance of a dry particle medium unlike a viscous fluid is said to be unaffected by...the mechanical components of the dampers are filled with selected particles. The advantages of particle damping over the conventional damping

Rotor blades for turbine engines

DOEpatents

Piersall, Matthew R; Potter, Brian D

2013-02-12

A tip shroud that includes a plurality of damping fins, each damping fin including a substantially non-radially-aligned surface that is configured to make contact with a tip shroud of a neighboring rotor blade. At least one damping fin may include a leading edge damping fin and at least one damping fin may include a trailing edge damping fin. The leading edge damping fin may be configured to correspond to the trailing edge damping fin.

Flash water-window x-ray generator with a ferrite capillary

NASA Astrophysics Data System (ADS)

Sato, Eiichi; Sagae, Michiaki; Ichimaru, Toshio; Takayama, Kazuyoshi; Sakamaki, Kimio; Tamakawa, Yoshiharu

1997-12-01

The fundamental study on a flash water-window x-ray generator is described. This generator is composed of a high-voltage power supply, a polarity-inversion high-voltage pulser, a krytron pulser as a trigger device, an oil-diffusion pump, and a vacuum chamber with a capillary. A combined ceramic condenser of about 5 nF in the pulser is charged up to 70 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing a gap switch by the krytron pulser. In the present work, the chamber is evacuated by the pump with a pressure of about 1 by 10-3 Pa, and the titanium anode and cathode electrodes are employed to produce L-series characteristic x rays in the water-window range. The diameter and the length of the ferrite capillary are 2.0 and 30 mm, respectively. Both the cathode voltage and the discharge current displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were minus 24 kV and 2.8 kA, respectively. The pulse durations of the water-window x-rays were nearly equivalent to those of the damped oscillations of the voltage and current, and their values were less than 10 microseconds.

Simulation of Thin-Film Damping and Thermal Mechanical Noise Spectra for Advanced Micromachined Microphone Structures.

PubMed

Hall, Neal A; Okandan, Murat; Littrell, Robert; Bicen, Baris; Degertekin, F Levent

2008-06-01

In many micromachined sensors the thin (2-10 μm thick) air film between a compliant diaphragm and backplate electrode plays a dominant role in shaping both the dynamic and thermal noise characteristics of the device. Silicon microphone structures used in grating-based optical-interference microphones have recently been introduced that employ backplates with minimal area to achieve low damping and low thermal noise levels. Finite-element based modeling procedures based on 2-D discretization of the governing Reynolds equation are ideally suited for studying thin-film dynamics in such structures which utilize relatively complex backplate geometries. In this paper, the dynamic properties of both the diaphragm and thin air film are studied using a modal projection procedure in a commonly used finite element software and the results are used to simulate the dynamic frequency response of the coupled structure to internally generated electrostatic actuation pressure. The model is also extended to simulate thermal mechanical noise spectra of these advanced sensing structures. In all cases simulations are compared with measured data and show excellent agreement-demonstrating 0.8 pN/√Hz and 1.8 μPa/√Hz thermal force and thermal pressure noise levels, respectively, for the 1.5 mm diameter structures under study which have a fundamental diaphragm resonance-limited bandwidth near 20 kHz.

The structure of affective action representations: temporal binding of affective response codes.

PubMed

Eder, Andreas B; Müsseler, Jochen; Hommel, Bernhard

2012-01-01

Two experiments examined the hypothesis that preparing an action with a specific affective connotation involves the binding of this action to an affective code reflecting this connotation. This integration into an action plan should lead to a temporary occupation of the affective code, which should impair the concurrent representation of affectively congruent events, such as the planning of another action with the same valence. This hypothesis was tested with a dual-task setup that required a speeded choice between approach- and avoidance-type lever movements after having planned and before having executed an evaluative button press. In line with the code-occupation hypothesis, slower lever movements were observed when the lever movement was affectively compatible with the prepared evaluative button press than when the two actions were affectively incompatible. Lever movements related to approach and avoidance and evaluative button presses thus seem to share a code that represents affective meaning. A model of affective action control that is based on the theory of event coding is discussed.

Investigation of He-W interactions using DiMES on DIII-D

NASA Astrophysics Data System (ADS)

Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.; Briesemeister, A. R.; Corr, C.; De Temmerman, G.; Kluth, P.; Lasnier, C. J.; McLean, A. G.; Pace, D. C.; Pitts, R. A.; Schmitz, O.; Thompson, M.; Winters, V.

2016-02-01

Tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225-850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in the surface of W buttons after only a single DIII-D (3 s, ˜150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04-0.1 MJ m-2.

eButton: A Wearable Computer for Health Monitoring and Personal Assistance

PubMed Central

Sun, Mingui; Burke, Lora E.; Mao, Zhi-Hong; Chen, Yiran; Chen, Hsin-Chen; Bai, Yicheng; Li, Yuecheng; Li, Chengliu; Jia, Wenyan

2014-01-01

Recent advances in mobile devices have made profound changes in people's daily lives. In particular, the impact of easy access of information by the smartphone has been tremendous. However, the impact of mobile devices on healthcare has been limited. Diagnosis and treatment of diseases are still initiated by occurrences of symptoms, and technologies and devices that emphasize on disease prevention and early detection outside hospitals are under-developed. Besides healthcare, mobile devices have not yet been designed to fully benefit people with special needs, such as the elderly and those suffering from certain disabilities, such blindness. In this paper, an overview of our research on a new wearable computer called eButton is presented. The concepts of its design and electronic implementation are described. Several applications of the eButton are described, including evaluating diet and physical activity, studying sedentary behavior, assisting the blind and visually impaired people, and monitoring older adults suffering from dementia. PMID:25340176

A novel wearable smart button system for fall detection

NASA Astrophysics Data System (ADS)

Zhuang, Wei; Sun, Xiang; Zhi, Yueyan; Han, Yue; Mao, Hande

2017-05-01

Fall has been the second most cause of accidental injury to death in the world. It has been a serious threat to the physical and mental health of the elders. Therefore, developing wearable node system with fall detecting ability has become increasingly pressing at present. A novel smart button for long-term fall detection is proposed in this paper, which is able to accurately monitor the falling behavior, and sending warning message online as well. The smart button is based on the tri-axis acceleration sensor which is used to collect the body motion signals. By using the statistical metrics of acceleration characteristics, a new SVM classification algorithm with high positive accuracy and stability is proposed so as to classify the falls and activities of daily living, and the results can be real-time displayed on Android based mobile phone. The experiments show that our wearable node system can continuously monitor the falling behavior with positive rate 94.8%.

Proceedings of Damping 1993, volume 3

NASA Astrophysics Data System (ADS)

Portis, Bonnie L.

1993-06-01

Presented are individual papers of Damping '93, held 24-26 February 1993 in San Francisco. The subjects included: passive damping concepts; passive damping analysis and design techniques; optimization; damped control/structure interaction; viscoelastic material testing and characterization; highly damped materials; vibration suppression techniques; damping identification and dynamic testing; applications to aircraft; space structures; Marine structures; and commercial products; defense applications; and payoffs of vibration suppression.

Proceedings of Damping 1993, volume 1

NASA Astrophysics Data System (ADS)

Portis, Bonnie L.

1993-06-01

Presented are individual papers of Damping '93 held 24-26 February, 1993, in San Francisco. The subjects included: passive damping concepts; passive damping analysis and design techniques; optimization; damped control/structure interaction; viscoelastic material testing and characterization; highly damped materials; vibration suppression techniques; damping identification and dynamic testing; application to aircraft; space structures; marine structures; commercial products; defense applications; and payoffs of vibration suppression.

Comparative Research on Characteristics of the Isolation Systems with Dry Friction Damping and with Vicious Damping under Base Excitation

NASA Astrophysics Data System (ADS)

Hou, Junfang; jing, Min; Zhang, Weihua; Lu, Yahui; He, Haiwen

2017-12-01

As for the isolation problem of electronic equipments on vehicle, the vibration response characteristics of dry friction damping isolation system under base displacement excitation was analyzed in theory by harmonic balance method, and the displacement response was compared between the isolation systems with dry friction damping and vicious damping separately. The results show that the isolation system with small dry friction damping can’t meet the demands of displacement reduction close to the natural frequency, and it can realize full-frequency vibration isolation by improving dry friction damping when the lock frequency passes beyond the resonance frequency band. The results imply that the damping mechanism of dry friction isolator can’t be described only by dry friction damping, and the composite damping with dry friction and vicious damping is more appropriate.

Field evaluation of personal sampling methods for multiple bioaerosols.

PubMed

Wang, Chi-Hsun; Chen, Bean T; Han, Bor-Cheng; Liu, Andrew Chi-Yeu; Hung, Po-Chen; Chen, Chih-Yong; Chao, Hsing Jasmine

2015-01-01

Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols.

Damping of gravitational waves by matter

NASA Astrophysics Data System (ADS)

Baym, Gordon; Patil, Subodh P.; Pethick, C. J.

2017-10-01

We develop a unified description, via the Boltzmann equation, of damping of gravitational waves by matter, incorporating collisions. We identify two physically distinct damping mechanisms—collisional and Landau damping. We first consider damping in flat spacetime, and then generalize the results to allow for cosmological expansion. In the first regime, maximal collisional damping of a gravitational wave, independent of the details of the collisions in the matter is, as we show, significant only when its wavelength is comparable to the size of the horizon. Thus damping by intergalactic or interstellar matter for all but primordial gravitational radiation can be neglected. Although collisions in matter lead to a shear viscosity, they also act to erase anisotropic stresses, thus suppressing the damping of gravitational waves. Damping of primordial gravitational waves remains possible. We generalize Weinberg's calculation of gravitational wave damping, now including collisions and particles of finite mass, and interpret the collisionless limit in terms of Landau damping. While Landau damping of gravitational waves cannot occur in flat spacetime, the expansion of the universe allows such damping by spreading the frequency of a gravitational wave of given wave vector.

Proceedings of Damping 1993, volume 2

NASA Astrophysics Data System (ADS)

Portis, Bonnie L.

1993-06-01

Presented are individual papers of Damping '93, held 24-26 Feb. 1993 in San Francisco. The subjects included the following: passive damping concepts; passive damping analysis and design techniques; optimization; damped control/structure interaction; viscoelastic material testing and characterization; highly damped materials; vibration suppression techniques; damping identification and dynamic testing; applications to aircraft; space structures; marine structures; and commercial products; defense applications; and payoffs of vibration suppression.

Affective ERP Processing in a Visual Oddball Task: Arousal, Valence, and Gender

PubMed Central

Rozenkrants, Bella; Polich, John

2008-01-01

Objective To assess affective event-related brain potentials (ERPs) using visual pictures that were highly distinct on arousal level/valence category ratings and a response task. Methods Images from the International Affective Pictures System (IAPS) were selected to obtain distinct affective arousal (low, high) and valence (negative, positive) rating levels. The pictures were used as target stimuli in an oddball paradigm, with a visual pattern as the standard stimulus. Participants were instructed to press a button whenever a picture occurred and to ignore the standard. Task performance and response time did not differ across conditions. Results High-arousal compared to low-arousal stimuli produced larger amplitudes for the N2, P3, early slow wave, and late slow wave components. Valence amplitude effects were weak overall and originated primarily from the later waveform components and interactions with electrode position. Gender differences were negligible. Conclusion The findings suggest that arousal level is the primary determinant of affective oddball processing, and valence minimally influences ERP amplitude. Significance Affective processing engages selective attentional mechanisms that are primarily sensitive to the arousal properties of emotional stimuli. The application and nature of task demands are important considerations for interpreting these effects. PMID:18783987

Hemodynamic and electrophysiological relationship involved in human face processing: evidence from a combined fMRI-ERP study.

PubMed

Iidaka, Tetsuya; Matsumoto, Atsushi; Haneda, Kaoruko; Okada, Tomohisa; Sadato, Norihiro

2006-03-01

Functional magnetic resonance imaging (fMRI) and event-related potential (ERP) experiments were conducted in the same group of subjects and with an identical task paradigm to investigate a possible relationship between hemodynamic and electrophysiological responses within the brain. The subjects were instructed to judge whether visually presented stimuli were faces or houses and then press the corresponding button. Functional MRI identified face- and house-related regions in the lateral and medial part of the fusiform gyrus, respectively, while ERP showed significantly greater N170 negativity for face than for house stimuli in the temporo-occipital electrodes. Correlation analysis between the BOLD signal in the fusiform gyrus and ERP parameters demonstrated a close relationship between the signal and both latency and amplitude of N170 across the subjects. These correlations may indicate that the variation in cognitive demand and hemodynamic responses during the face/house discrimination task is coupled with the variation of N170 peak latency/amplitude across the subjects. Thus, integrative analysis of spatial and temporal information obtained from the two experimental modalities may help in studying neural correlates involved in a particular cognitive task.

Re-Engineering the United States Marine Corps’ Enlisted Assignment Model (EAM)

DTIC Science & Technology

1998-06-01

and Execution button opens the switchboard in Figure 12. This form accesses all of the VBA code that is associated with this form and the code that...the prototype to prompt the user and to inform him of what he is about to do. Each of the buttons that are on these forms is connected to an SQL ...into the field for building a rule are the values 2;3;4;5;6;7. The user can enter an SQL statement that would determine the values or the user could

ALLTEM System User’s Manual, Munitions Management Projects, ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation, Version 1.0

DTIC Science & Technology

2012-03-05

Alarm button. Under the GPS frame are two smaller frames. On the left is a frame with buttons labeled Tractor Guidance and Acquisition Error... GPS ) and the Attitude Heading Reference System (AHRS) data. 5.2 Using the Data Acquisition Simulator Software The simulator and a practice set... acquisition for one polarity of the TX (33ms dead band for relay switching + 33 ms of waveforms). When the GPS is being used this is usually “1”, but may be

Coplanar electrowetting-induced stirring as a tool to manipulate biological samples in lubricated digital microfluidics. Impact of ambient phase on drop internal flow patterna)

PubMed Central

Davoust, Laurent; Fouillet, Yves; Malk, Rachid; Theisen, Johannes

2013-01-01

Oscillating electrowetting on dielectrics (EWOD) with coplanar electrodes is investigated in this paper as a way to provide efficient stirring within a drop with biological content. A supporting model inspired from Ko et al. [Appl. Phys. Lett. 94, 194102 (2009)] is proposed allowing to interpret oscillating EWOD-induced drop internal flow as the result of a current streaming along the drop surface deformed by capillary waves. Current streaming behaves essentially as a surface flow generator and the momentum it sustains within the (viscous) drop is even more significant as the surface to volume ratio is small. With the circular electrode pair considered in this paper, oscillating EWOD sustains toroidal vortical flows when the experiments are conducted with aqueous drops in air as ambient phase. But when oil is used as ambient phase, it is demonstrated that the presence of an electrode gap is responsible for a change in drop shape: a pinch-off at the electrode gap yields a peanut-shaped drop and a symmetry break-up of the EWOD-induced flow pattern. Viscosity of oil is also responsible for promoting an efficient damping of the capillary waves which populate the surface of the actuated drop. As a result, the capillary network switches from one standing wave to two superimposed traveling waves of different mechanical energy, provided that actuation frequency is large enough, for instance, as large as the one commonly used in electrowetting applications (f ∼ 500 Hz and beyond). Special emphasis is put on stirring of biological samples. As a typical application, it is demonstrated how beads or cell clusters can be focused under flow either at mid-height of the drop or near the wetting plane, depending on how the nature of the capillary waves is (standing or traveling), and therefore, depending on the actuation frequency (150 Hz–1 KHz). PMID:24404038

Integrated mechanics for the passive damping of polymer-matrix composites and composite structures

NASA Technical Reports Server (NTRS)

Saravanos, D. A.; Chamis, Christos C.

1991-01-01

Some recent developments on integrated damping mechanics for unidirectional composites, laminates, and composite structures are reviewed. Simplified damping micromechanics relate the damping of on-axis and off-axis composites to constituent properties, fiber volume ratio, fiber orientation, temperature, and moisture. Laminate and structural damping mechanics for thin composites are summarized. Discrete layer damping mechanics for thick laminates, including the effects of interlaminar shear damping, are developed and semianalytical predictions of modal damping in thick simply supported specialty composite plates are presented. Applications show the advantages of the unified mechanics, and illustrate the effect of fiber volume ratio, fiber orientation, structural geometry, and temperature on the damping. Additional damping properties for composite plates of various laminations, aspect ratios, fiber content, and temperature illustrate the merits and ranges of applicability of each theory (thin or thick laminates).

Study of modal coupling procedures for the shuttle: A matrix method for damping synthesis

NASA Technical Reports Server (NTRS)

Hasselman, T. K.

1972-01-01

The damping method was applied successfully to real structures as well as analytical models. It depends on the ability to determine an appropriate modal damping matrix for each substructure. In the past, modal damping matrices were assumed diagonal for lack of being able to determine the coupling terms which are significant in the general case of nonproportional damping. This problem was overcome by formulating the damped equations of motion as a linear perturbation of the undamped equations for light structural damping. Damped modes are defined as complex vectors derived from the complex frequency response vectors of each substructure and are obtained directly from sinusoidal vibration tests. The damped modes are used to compute first order approximations to the modal damping matrices. The perturbation approach avoids ever having to solve a complex eigenvalue problem.

Vibration damping characteristics of graphite/epoxy composites for large space structures

NASA Technical Reports Server (NTRS)

Gibson, R. F.

1982-01-01

Limited data on extensional and flexural damping of small specimens of graphite/epoxy and unreinforced epoxy resin were obtained. Flexural damping was measured using a forced vibration technique based on resonant flexural vibration of shaker excited double cantilever specimens. Extensional damping was measured by subjecting similar specimens to low frequency sinusoidal oscillation in a servohydraulic tensile testing machine while plotting load versus extensional strain. Damping was found to vary slowly and continuously over the frequency range 0.01 - 1000 Hz, and no drastic transitions were observed. Composite damping was found to be less than neat resin damping. Comparison of small specimen damping values with assembled column damping values seems to indicate that, for those materials, material damping is more important than joint damping. The data reported was limited not by the test apparatus, but by signal conditioning and data acquisition. It is believed that filtering of the strain gage signals and the use of digital storage with slow playback will make it possible to extend the frequency and amplitude ranges significantly.

Hybrid Damping System for an Electronic Equipment Mounting Shelf

NASA Technical Reports Server (NTRS)

Voracek, David; Kolkailah, Faysal A.; Cavalli, J. R.; Elghandour, Eltahry

1997-01-01

The objective of this study was to design and construct a vibration control system for an electronic equipment shelf to be evaluated in the NASA Dryden FTF-II. The vibration control system was a hybrid system which included passive and active damping techniques. Passive damping was fabricated into the equipment shelf using ScothDamp(trademark) damping film and aluminum constraining layers. Active damping was achieved using a two channel active control circuit employing QuickPack(trademark) sensors and actuators. Preliminary Chirp test results indicated passive damping smoothed the frequency response while active damping reduced amplitudes of the frequency response for most frequencies below 500Hz.

Hybrid Damping System for an Electronic Equipment Mounting Shelf

NASA Technical Reports Server (NTRS)

Voracek, David; Kolkailah, Faysal A.; Cavalli, J. R.; Elghandour, Eltahry

1997-01-01

The objective of this study was to design and construct a vibration control system for an electronic equipment shelf to be evaluated in the NASA Dryden FTF-11. The vibration control system was a hybrid system which included passive and active damping techniques. Passive damping was fabricated into the equipment shelf using ScothDamp(trademark) damping film and aluminum constraining layers. Active damping was achieved using a two channel active control circuit employing QuickPack(trademark) sensors and actuators. Preliminary Chirp test results indicated passive damping smoothed the frequency response while active damping reduced amplitudes of the frequency response for most frequencies below 500Hz.

A soft damping function for dispersion corrections with less overfitting

NASA Astrophysics Data System (ADS)

Ucak, Umit V.; Ji, Hyunjun; Singh, Yashpal; Jung, Yousung

2016-11-01

The use of damping functions in empirical dispersion correction schemes is common and widespread. These damping functions contain scaling and damping parameters, and they are usually optimized for the best performance in practical systems. In this study, it is shown that the overfitting problem can be present in current damping functions, which can sometimes yield erroneous results for real applications beyond the nature of training sets. To this end, we present a damping function called linear soft damping (lsd) that suffers less from this overfitting. This linear damping function damps the asymptotic curve more softly than existing damping functions, attempting to minimize the usual overcorrection. The performance of the proposed damping function was tested with benchmark sets for thermochemistry, reaction energies, and intramolecular interactions, as well as intermolecular interactions including nonequilibrium geometries. For noncovalent interactions, all three damping schemes considered in this study (lsd, lg, and BJ) roughly perform comparably (approximately within 1 kcal/mol), but for atomization energies, lsd clearly exhibits a better performance (up to 2-6 kcal/mol) compared to other schemes due to an overfitting in lg and BJ. The number of unphysical parameters resulting from global optimization also supports the overfitting symptoms shown in the latter numerical tests.

Experimental determination of material damping using vibration analyzer

NASA Technical Reports Server (NTRS)

Chowdhury, Mostafiz R.; Chowdhury, Farida

1990-01-01

Structural damping is an important dynamic characteristic of engineering materials that helps to damp vibrations by reducing their amplitudes. In this investigation, an experimental method is illustrated to determine the damping characteristics of engineering materials using a dual channel Fast Fourier Transform (FFT) analyzer. A portable Compaq III computer which houses the analyzer, is used to collect the dynamic responses of three metal rods. Time-domain information is analyzed to obtain the logarithmic decrement of their damping. The damping coefficients are then compared to determine the variation of damping from material to material. The variations of damping from one point to another of the same material, due to a fixed point excitation, and the variable damping at a fixed point due to excitation at different points, are also demonstrated.

Transient human auditory cortex activation during volitional attention shifting

PubMed Central

Uhlig, Christian Harm; Gutschalk, Alexander

2017-01-01

While strong activation of auditory cortex is generally found for exogenous orienting of attention, endogenous, intra-modal shifting of auditory attention has not yet been demonstrated to evoke transient activation of the auditory cortex. Here, we used fMRI to test if endogenous shifting of attention is also associated with transient activation of the auditory cortex. In contrast to previous studies, attention shifts were completely self-initiated and not cued by transient auditory or visual stimuli. Stimuli were two dichotic, continuous streams of tones, whose perceptual grouping was not ambiguous. Participants were instructed to continuously focus on one of the streams and switch between the two after a while, indicating the time and direction of each attentional shift by pressing one of two response buttons. The BOLD response around the time of the button presses revealed robust activation of the auditory cortex, along with activation of a distributed task network. To test if the transient auditory cortex activation was specifically related to auditory orienting, a self-paced motor task was added, where participants were instructed to ignore the auditory stimulation while they pressed the response buttons in alternation and at a similar pace. Results showed that attentional orienting produced stronger activity in auditory cortex, but auditory cortex activation was also observed for button presses without focused attention to the auditory stimulus. The response related to attention shifting was stronger contralateral to the side where attention was shifted to. Contralateral-dominant activation was also observed in dorsal parietal cortex areas, confirming previous observations for auditory attention shifting in studies that used auditory cues. PMID:28273110

Correlating bilayer tablet delamination tendencies to micro-environmental thermodynamic conditions during pan coating.

PubMed

Zacour, Brian M; Pandey, Preetanshu; Subramanian, Ganeshkumar; Gao, Julia Z; Nikfar, Faranak

2014-06-01

The objective of this study was to determine the impact that the micro-environment, as measured by PyroButton data loggers, experienced by tablets during the pan coating unit operation had on the layer adhesion of bilayer tablets in open storage conditions. A full factorial design of experiments (DOE) with three center points was conducted to study the impact of final tablet hardness, film coating spray rate and film coating exhaust temperature on the delamination tendencies of bilayer tablets. PyroButton data loggers were placed (fixed) at various locations in a pan coater and were also allowed to freely move with the tablet bed to measure the micro-environmental temperature and humidity conditions of the tablet bed. The variance in the measured micro-environment via PyroButton data loggers accounted for 75% of the variance in the delamination tendencies of bilayer tablets on storage (R(2 )= 0.75). A survival analysis suggested that tablet hardness and coating spray rate significantly impacted the delamination tendencies of the bilayer tablets under open storage conditions. The coating exhaust temperature did not show good correlation with the tablets' propensity to crack indicating that it was not representative of the coating micro-environment. Models created using data obtained from the PyroButton data loggers outperformed models created using primary DOE factors in the prediction of bilayer tablet strength, especially upon equipment or scale transfers. The coating micro-environment experienced by tablets during the pan coating unit operation significantly impacts the strength of the bilayer interface of tablets on storage.

Results of minimal invasive coracoclavicular fixation by double button lift-up system in Neer type II distal clavicle fractures.

PubMed

Dedeoğlu, Süleyman Semih; İmren, Yunus; Çabuk, Haluk; Çakar, Murat; Arslan, Samet Murat; Esenyel, Cem Zeki

2017-01-01

We aimed to evaluate clinical and functional outcomes of indirect fracture reduction performed by coracoclavicular fixation with minimal invasive double button lift-up system in Neer type IIa unstable fractures of distal clavicle. 22 patients with Neer type 2 distal clavicle fracture were enrolled in that prospective study. All patients underwent indirect reduction and osteosynthesis performed by coracoclavicular fixation with minimal invasive double button lift-up system. Postoperative follow-up was carried out clinically and radiologically with plain X-rays and utilization of Constant and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment (ASES) shoulder scores. Mean follow-up time was 15 months. A standard sling was applied for 2 weeks, postoperatively. Rehabilitation program was started on postoperative day 1. Mean age was 39 (range: 21-60), 18 of the patients were male. Right dominant extremity was affected in 14 patients. Mean duration of the surgical intervention was 40 min (range: 30-55 min). Mean union time was found to be 14 weeks (range: 7-21 weeks). Mean postoperative ASES and Constant scores were 79.9 (66.9-88.3) and 82.2 (71-100), respectively. The duration of return to normal daily activities were found to be 4.5 months. Any loss of reduction, AC joint arthrosis, and clavicular shortening were not detected in X-rays. This study has demonstrated that indirect osteosynthesis performed by coracoclavicular fixation with double button lift-up system in the treatment of unstable Neer type IIa fractures of the distal clavicle had successful clinical, radiological, and functional outcomes.

Esophageal lesions following button-battery ingestion in children: Analysis of causes and proposals for preventive measures.

PubMed

Lahmar, J; Célérier, C; Garabédian, E N; Couloigner, V; Leboulanger, N; Denoyelle, F

2018-04-01

To study recent cases of esophageal injury due to button-battery ingestion in children presenting in pediatric ENT emergency departments of the Paris area of France (Île-de-France region), in order to propose appropriate preventive measures. A retrospective descriptive single-center study included all children under 15 years of age, presenting in pediatric ENT emergency departments between January 2008 and April 2014 for button-battery ingestion with esophageal impaction requiring emergency removal. Twenty-two boys and 4 girls, with a median age of 25 months, were included. Twenty-five of the 26 batteries had diameters of 20mm or more. Median esophageal impaction time was 7 hours 30 minutes (range, 2 to 72 hours). The complications rate was 23%. Mean hospital stay cost was €38,751 (range, €5130-119,737). The origin of the battery was known in 23 of the 26 cases: remote control without screw-secured compartment (42.3%), open battery pack (15.4%), children's toy (15.3%), camera (7.7%), watch (1 case) and hearing aid without screw-secured compartment (1 case). Esophageal lesions due to ingestion of button-batteries in children are almost always due to batteries larger than 20mm in diameter, mostly from devices with a poorly protected compartment, or batteries that are not individually packaged. These lesions cause serious complications in a quarter of cases and their management entails high health costs. Legislation requiring screw-secured compartments and individual blisters for batteries could have prevented 69.2% of the ingestions. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Experimental vibration damping characteristics of the third-stage rotor of a three-stage transonic axial-flow compressor

NASA Technical Reports Server (NTRS)

Newman, Frederick A.

1988-01-01

Rotor blade aerodynamic damping is experimentally determined in a three-stage transonic axial flow compressor having design aerodynamic performance goals of 4.5:1 pressure ratio and 65.5 lbm/sec weight flow. The combined damping associated with each mode is determined by a least squares fit of a single degree of freedom system transfer function to the nonsynchronous portion of the rotor blade strain gage output power spectra. The combined damping consists of the aerodynanmic damping and the structural and mechanical damping. The aerodynamic damping varies linearly with the inlet total pressure for a given corrected speed, weight flow, and pressure ratio while the structural and mechanical damping is assumed to remain constant. The combined damping is determined at three inlet total pressure levels to obtain the aerodynamic damping. The third-stage rotor blade aerodynamic damping is presented and discussed for the design equivalent speed with the stator blades reset for maximum efficiency. The compressor overall performance and experimental Campbell diagrams for the third-stage rotor blade row are also presented.

Experimental Vibration Damping Characteristics of the Third-stage Rotor of a Three-stage Transonic Axial-flow Compressor

NASA Technical Reports Server (NTRS)

Newman, Frederick A.

1988-01-01

Rotor blade aerodynamic damping is experimentally determined in a three-stage transonic axial flow compressor having design aerodynamic performance goals of 4.5:1 pressure ratio and 65.5 lbm/sec weight flow. The combined damping associated with each mode is determined by a least squares fit of a single degree of freedom system transfer function to the nonsynchronous portion of the rotor blade strain gage output power spectra. The combined damping consists of the aerodynamic damping and the structural and mechanical damping. The aerodynamic damping varies linearly with the inlet total pressure for a given corrected speed, weight flow, and pressure ratio while the structural and mechanical damping is assumed to remain constant. The combined damping is determined at three inlet total pressure levels to obtain the aerodynamic damping. The third-stage rotor blade aerodynamic damping is presented and discussed for the design equivalent speed with the stator blades reset for maximum efficiency. The compressor overall preformance and experimental Campbell diagrams for the third-stage rotor blade row are also presented.

User interface customization on Endoscopy Department Mini-PACS and its impact on examination workflow

NASA Astrophysics Data System (ADS)

Osada, Masakazu; Kaise, Mitsuru; Ozeki, Takeshi; Tsunakawa, Hirofumi; Tsunakawa, Kiyoshi; Takayanagi, Takashi; Suzuki, Nobuaki; Miwa, Jun; Ohta, Yasuhiko; Kanai, Koichi

1999-07-01

We have proposed a new user interface with workflow customization, implemented and evaluted in Endoscopy Department Mini-PACS that has been introduced and routinely used for two years at Toshiba General Hospital. We have set some task at endoscopy image acquisition units during examinations for two different types of user interfaces and compared performance. One is a command-button based operation using a remote control, and another is that with eight graphic buttons which are displayed on a CRT monitor and can be customized. Results of the two-year study show that mean number of input diagnosis codes per examination with graphic and customized interface is significantly greater than that with conventional interface. Also, mean time to complete one upper gastric endoscopy examination with new user interface is about 17 percent less than that with conventional interface. These result suggest that systems with the visualized and customized operation and feedback encourages physicians to use more functions and to compete tasks more efficiently than systems with conventional command-button based user interfaces.

Concepts for multi-IFU robotic positioning systems

NASA Astrophysics Data System (ADS)

Miziarski, Stan; Brzeski, Jurek; Bland Hawthorn, Joss; Gilbert, James; Goodwin, Michael; Heijmans, Jeroen; Horton, Anthony; Lawrence, Jon; Saunders, Will; Smith, Greg A.; Staszak, Nicholas

2012-09-01

Following the successful commissioning of SAMI (Sydney-AAO Multi-object IFU) the AAO has undertaken concept studies leading to a design of a new instrument for the AAT (Hector). It will use an automated robotic system for the deployment of fibre hexabundles to the focal plane. We have analysed several concepts, which could be applied in the design of new instruments or as a retrofit to existing positioning systems. We look at derivatives of Starbugs that could handle a large fibre bundle as well as modifications to pick and place robots like 2dF or OzPoz. One concept uses large magnetic buttons that adhere to a steel field plate with substantial force. To move them we replace the gripper with a pneumatic device, which engages with the button and injects it with compressed air, thus forming a magnet preloaded air bearing allowing virtually friction-less repositioning of the button by a gantry or an R-Theta robot. New fibre protection, guiding and retraction systems are also described. These developments could open a practical avenue for the upgrade to a number of instruments.

Early event-related brain potentials that reflect interest for content information in the media.

PubMed

Adachi, Shinobu; Morikawa, Koji; Nittono, Hiroshi

2012-03-28

This study investigated the relationship between event-related brain potentials (ERPs) to abridged content information in the media and the subsequent decisions to view the full content. Student volunteers participated in a task that simulated information selection on the basis of the content information. Screenshots of television clips and headlines of news articles on the Web were used as content information for the image condition and the headline condition, respectively. Following presentation of a stimulus containing content information, participants decided whether or not they would view the full content by pressing a select or a reject button. When the select button was pressed, participants were presented with a television clip or a news article. When the reject button was pressed, participants continued on to the next trial, without viewing further. In comparison with rejected stimuli, selected stimuli elicited a larger negative component, with a peak latency of ∼250 ms. The increase in the negative component was independent of the type of visual stimulus. These results suggest that interest toward content information is reflected in early-stage event-related brain potential responses.

Investigation of He–W interactions using DiMES on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.

Here, tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225–850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in themore » surface of W buttons after only a single DIII-D (3 s, ~150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04–0.1 MJ m –2.« less

Investigation of He–W interactions using DiMES on DIII-D

DOE PAGES

Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.; ...

2016-01-22

Here, tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225–850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in themore » surface of W buttons after only a single DIII-D (3 s, ~150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04–0.1 MJ m –2.« less

Highly-Damped Spectral Acceleration as a Ground Motion Intensity Measure for Estimating Collapse Vulnerability of Buildings

NASA Astrophysics Data System (ADS)

Buyco, K.; Heaton, T. H.

2016-12-01

Current U.S. seismic code and performance-based design recommendations quantify ground motion intensity using 5%-damped spectral acceleration when estimating the collapse vulnerability of buildings. This intensity measure works well for predicting inter-story drift due to moderate shaking, but other measures have been shown to be better for estimating collapse risk.We propose using highly-damped (>10%) spectral acceleration to assess collapse vulnerability. As damping is increased, the spectral acceleration at a given period T begins to behave like a weighted average of the corresponding lowly-damped (i.e. 5%) spectrum at a range of periods. Weights for periods longer than T increase as damping increases. Using high damping is physically intuitive for two reasons. Firstly, ductile buildings dissipate a large amount of hysteretic energy before collapse and thus behave more like highly-damped systems. Secondly, heavily damaged buildings experience period-lengthening, giving further credence to the weighted-averaging property of highly-damped spectral acceleration.To determine the optimal damping value(s) for this ground motion intensity measure, we conduct incremental dynamic analysis for a suite of ground motions on several different mid-rise steel buildings and select the damping value yielding the lowest dispersion of intensity at the collapse threshold. Spectral acceleration calculated with damping as high as 70% has been shown to be a better indicator of collapse than that with 5% damping.

Determination of the structural damping coefficients of six full-scale helicopter rotor blades of different materials and methods of construction

NASA Technical Reports Server (NTRS)

Gibson, Frederick W

1956-01-01

Results of an experimental investigation of the structural damping of six full-scale helicopter rotor blades, made to determine the variation of structural damping with materials and methods of construction, are presented. The damping of the blades was determined for the first three flapwise bending modes, first chordwise bending mode, and first torsion mode. The contribution of structural damping to the total damping of the blades is discussed for several aerodynamic conditions in order to point out situations where structural damping is significant.

Dynamic characteristics of specialty composite structures with embedded damping layers

NASA Technical Reports Server (NTRS)

Saravanos, D. A.; Chamis, C. C.

1993-01-01

Damping mechanics for simulating the damped dynamic characteristics in specialty composite structures with compliant interlaminar damping layers are presented. Finite-element based mechanics incorporating a discrete layer (or layer-wise) laminate damping theory are utilized to represent general laminate configurations in terms of lay-up and fiber orientation angles, cross-sectional thickness, shape, and boundary conditions. Evaluations of the method with exact solutions and experimental data illustrate the accuracy of the method. Additional applications investigate the potential for significant damping enhancement in angle-ply composite laminates with cocured interlaminar damping layers.

What Orthopaedic Operating Room Surfaces Are Contaminated With Bioburden? A Study Using the ATP Bioluminescence Assay.

PubMed

Richard, Raveesh Daniel; Bowen, Thomas R

2017-07-01

Contaminated operating room surfaces can increase the risk of orthopaedic infections, particularly after procedures in which hardware implantation and instrumentation are used. The question arises as to how surgeons can measure surface cleanliness to detect increased levels of bioburden. This study aims to highlight the utility of adenosine triphosphate (ATP) bioluminescence technology as a novel technique in detecting the degree of contamination within the sterile operating room environment. What orthopaedic operating room surfaces are contaminated with bioburden? When energy is required for cellular work, ATP breaks down into adenosine biphosphate (ADP) and phosphate (P) and in that process releases energy. This process is inherent to all living things and can be detected as light emission with the use of bioluminescence assays. On a given day, six different orthopaedic surgery operating rooms (two adult reconstruction, two trauma, two spine) were tested before surgery with an ATP bioluminescence assay kit. All of the cases were considered clean surgery without infection, and this included the previously performed cases in each sampled room. These rooms had been cleaned and prepped for surgery but the patients had not been physically brought into the room. A total of 13 different surfaces were sampled once in each room: the operating room (OR) preparation table (both pre- and postdraping), OR light handles, Bovie machine buttons, supply closet countertops, the inside of the Bair Hugger™ hose, Bair Hugger™ buttons, right side of the OR table headboard, tourniquet machine buttons, the Clark-socket attachment, and patient positioners used for total hip and spine positioning. The relative light units (RLUs) obtained from each sample were recorded and data were compiled and averaged for analysis. These values were compared with previously published ATP benchmark values of 250 to 500 RLUs to define cleanliness in both the hospital and restaurant industries. All surfaces had bioburden. The ATP RLUs (mean ± SD) are reported for each surface in ascending order: the OR preparation table (postdraping; 8.3 ± 3.4), inside the sterilized pan (9.2 ± 5.5), the inside of the Bair Hugger™ hose (212.5 ± 155.7), supply closet countertops (281.7 ± 236.7), OR light handles (647.8 ± 903.7), the OR preparation table (predraping; 1054 ± 387.5), the Clark-socket attachment (1135.7 ± 705.3), patient positioners used for total hip and spine positioning (1201.7 ± 1144.9), Bovie machine buttons (1264.5 ± 638.8), Bair Hugger™ buttons (1340.8 ± 1064.1), tourniquet machine buttons (1666.5 ± 2144.9), computer keyboard (1810.8 ± 929.6), and the right side of the OR table headboard (2539 ± 5635.8). ATP bioluminescence is a novel method to measure cleanliness within the orthopaedic OR and can help identify environmental trouble spots that can potentially lead to increased infection rates. Future studies correlating ATP bioluminescence findings with microbiology cultures could add to the clinical utility of this technology. Surfaces such as the undersurface of the OR table headboard, Bair Hugger™ buttons, and tourniquet machine buttons should be routinely cleansed as part of an institutional protocol. Although correlation between ATP bioluminescence and clinical infection was not evaluated in this study, it is the subject of future research. Specifically, evaluating microbiology samples taken from these environmental surfaces and correlating them with increased bioburden found with ATP bioluminescence technology can help promote improved surgical cleaning practices.

Evaluation of Drogue Parachute Damping Effects Utilizing the Apollo Legacy Parachute Model

NASA Technical Reports Server (NTRS)

Currin, Kelly M.; Gamble, Joe D.; Matz, Daniel A.; Bretz, David R.

2011-01-01

Drogue parachute damping is required to dampen the Orion Multi Purpose Crew Vehicle (MPCV) crew module (CM) oscillations prior to deployment of the main parachutes. During the Apollo program, drogue parachute damping was modeled on the premise that the drogue parachute force vector aligns with the resultant velocity of the parachute attach point on the CM. Equivalent Cm(sub q) and Cm(sub alpha) equations for drogue parachute damping resulting from the Apollo legacy parachute damping model premise have recently been developed. The MPCV computer simulations ANTARES and Osiris have implemented high fidelity two-body parachute damping models. However, high-fidelity model-based damping motion predictions do not match the damping observed during wind tunnel and full-scale free-flight oscillatory motion. This paper will present the methodology for comparing and contrasting the Apollo legacy parachute damping model with full-scale free-flight oscillatory motion. The analysis shows an agreement between the Apollo legacy parachute damping model and full-scale free-flight oscillatory motion.

Macroscopic damping model for structural dynamics with random polycrystalline configurations

NASA Astrophysics Data System (ADS)

Yang, Yantao; Cui, Junzhi; Yu, Yifan; Xiang, Meizhen

2018-06-01

In this paper the macroscopic damping model for dynamical behavior of the structures with random polycrystalline configurations at micro-nano scales is established. First, the global motion equation of a crystal is decomposed into a set of motion equations with independent single degree of freedom (SDOF) along normal discrete modes, and then damping behavior is introduced into each SDOF motion. Through the interpolation of discrete modes, the continuous representation of damping effects for the crystal is obtained. Second, from energy conservation law the expression of the damping coefficient is derived, and the approximate formula of damping coefficient is given. Next, the continuous damping coefficient for polycrystalline cluster is expressed, the continuous dynamical equation with damping term is obtained, and then the concrete damping coefficients for a polycrystalline Cu sample are shown. Finally, by using statistical two-scale homogenization method, the macroscopic homogenized dynamical equation containing damping term for the structures with random polycrystalline configurations at micro-nano scales is set up.

Automatic multiple-sample applicator and electrophoresis apparatus

NASA Technical Reports Server (NTRS)

Grunbaum, B. W. (Inventor)

1977-01-01

An apparatus for performing electrophoresis and a multiple-sample applicator is described. Electrophoresis is a physical process in which electrically charged molecules and colloidal particles, upon the application of a dc current, migrate along a gel or a membrane that is wetted with an electrolyte. A multiple-sample applicator is provided which coacts with a novel tank cover to permit an operator either to depress a single button, thus causing multiple samples to be deposited on the gel or on the membrane simultaneously, or to depress one or more sample applicators separately by means of a separate button for each applicator.

Assessment of pediatric Malone antegrade continence enema (MACE) complications: Effects of variations in technique.

PubMed

Saikaly, Sami K; Rich, Mark A; Swana, Hubert S

2016-08-01

The Malone antegrade continence enema (MACE) procedure is performed for patients with fecal incontinence and constipation who do not respond to medical therapy. The MACE procedure provides antegrade catheter access to the right colon and allows administration of enemas to help evacuate the bowel regularly. The objective of this study was to identify risk factors for surgical complications in children who undergo the MACE procedure. Records from 97 pediatric patients who underwent MACE procedure were reviewed retrospectively. Data collected included age, sex, weight (obese/not obese), stomal location, presence of a permanent button/catheter in the stoma, open vs. laparoscopic surgery, and etiology of fecal incontinence/constipation. The complications reviewed included stomal stenosis, leakage, and stomal site infection. The relationships between the independent variables and complications were assessed using chi-square tests and Fisher's exact test. Statistical significance was set at p < 0.05. Overall, 66 (68%) patients had at least one complication. Twenty-three (23.7%) patients developed stomal stenosis, and 27 (27.8%) patients had significant stomal leakage. Insertion of a stomal button/catheter device was associated with an increased risk of developing stomal leakage and stomal infection. The presence of a stomal button/catheter was also associated with a decreased risk of stomal stenosis (Figure). The non-intubated, imbricated sub-population, preteen patients (<12 years old) experienced more stomal leakage than teenage patients. In this subgroup, patients with umbilical stomas also experienced more leakage than patients with right lower quadrant (RLQ) stomas. The prevalence rates of stomal complications in our study were consistent with previously reported series. In our study, however, stomal leakage had a higher prevalence in comparison with stomal stenosis. This seems to be related to the heterogeneity of the study group, which contained two variants of the MACE procedure; non-imbricated, intubated MACE and imbricated, non-intubated MACE. The use of stomal buttons in conjunction with MACE has previously been reported without changes in complication rates. We found the use of stomal buttons/catheters to be associated with changes in the prevalence of stomal complications. Stomal complications are common in the MACE procedure. The use of a permanent stomal button/catheter is associated with changes in the rates of stomal complications. While many find an umbilical stomal site is more cosmetically appealing, there is an increased risk of leakage with imbricated, non-intubated stomas. In the non-intubated, imbricated sub-population, the MACE procedure results in a higher risk of stomal leakage in preteen patients in comparison with teenage patients. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Superconductive material and magnetic field for damping and levitation support and damping of cryogenic instruments

NASA Technical Reports Server (NTRS)

Dolgin, Benjamin P. (Inventor)

1994-01-01

A superconductive load bearing support without a mechanical contact and vibration damping for cryogenic instruments in space is presented. The levitation support and vibration damping is accomplished by the use of superconducting magnets and the 'Meissner' effect. The assembly allows for transfer of vibration energy away from the cryogenic instrument which then can be damped by the use of either an electronic circuit or conventional vibration damping mean.

Structural damping studies at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Young, Clarence P., Jr.; Buehrle, Ralph D.

1994-01-01

Results of an engineering study to measure changes in structural damping properties of two cryogenic wind tunnel model systems and two metallic test specimens at cryogenic temperatures are presented. Data are presented which indicate overall, a trend toward reduced structural damping at cryogenic temperatures (-250 degrees F) when compared with room temperature damping properties. The study was focused on structures and materials used for model systems tested in the National Transonic Facility (NTF). The study suggests that the significant reductions in damping at extremely cold temperatures are most likely associated with changes in mechanical joint compliance damping rather than changes in material (solid) damping.

Finite element analysis of damped vibrations of laminated composite plates

NASA Astrophysics Data System (ADS)

Hu, Baogang

1992-11-01

Damped free vibrations of composite laminates are subjected to macromechanical analysis. Two models are developed: a viscoelastic damping model and a specific damping capacity model. The important symmetry property of the damping matrix is retained in both models. A modified modal strain energy method is proposed for evaluating modal damping in the viscoelastic model using a real (instead of a complex) eigenvalue problem solution. Numerical studies of multidegree of freedom systems are conducted to illustrate the improved accuracy of the method compared to the modal strain energy method. The experimental data reported in the literature for damped free vibrations in both polymer matrix and metal matrix composites were used in finite element analysis to test and compare the damping models. The natural frequencies and modal damping were obtained using both the viscoelastic and specific models. Results from both models are in satisfactory agreement with experimental data. Both models were found to be reasonably accurate for systems with low damping. Parametric studies were conducted to examine the effects on damping of the side to thickness ratio, the principal moduli ratio, the total number of layers, the ply angle, and the boundary conditions.

Damping Analysis of Cylindrical Composite Structures with Enhanced Viscoelastic Properties

NASA Astrophysics Data System (ADS)

Kliem, Mathias; Høgsberg, Jan; Vanwalleghem, Joachim; Filippatos, Angelos; Hoschützky, Stefan; Fotsing, Edith-Roland; Berggreen, Christian

2018-04-01

Constrained layer damping treatments are widely used in mechanical structures to damp acoustic noise and mechanical vibrations. A viscoelastic layer is thereby applied to a structure and covered by a stiff constraining layer. When the structure vibrates in a bending mode, the viscoelastic layer is forced to deform in shear mode. Thus, the vibration energy is dissipated as low grade frictional heat. This paper documents the efficiency of passive constrained layer damping treatments for low frequency vibrations of cylindrical composite specimens made of glass fibre-reinforced plastics. Different cross section geometries with shear webs have been investigated in order to study a beneficial effect on the damping characteristics of the cylinder. The viscoelastic damping layers are placed at different locations within the composite cylinder e.g. circumferential and along the neutral plane to evaluate the location-dependent efficiency of constrained layer damping treatments. The results of the study provide a thorough understanding of constrained layer damping treatments and an improved damping design of the cylindrical composite structure. The highest damping is achieved when placing the damping layer in the neutral plane perpendicular to the bending load. The results are based on free decay tests of the composite structure.

Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays.

PubMed

Wen, Long; Chen, Qin; Song, Shichao; Yu, Yan; Jin, Lin; Hu, Xin

2015-07-03

We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

Ultra-low magnetic damping in metallic and half-metallic systems

NASA Astrophysics Data System (ADS)

Shaw, Justin

The phenomenology of magnetic damping is of critical importance to devices which seek to exploit the electronic spin degree of freedom since damping strongly affects the energy required and speed at which a device can operate. However, theory has struggled to quantitatively predict the damping, even in common ferromagnetic materials. This presents a challenge for a broad range of applications in magnonics, spintronics and spin-orbitronics that depend on the ability to precisely control the damping of a material. I will discuss our recent work to precisely measure the intrinsic damping in several metallic and half-metallic material systems and compare experiment with several theoretical models. This investigation uncovered a metallic material composed of Co and Fe that exhibit ultra-low values of damping that approach values found in thin film YIG. Such ultra-low damping is unexpected in a metal since magnon-electron scattering dominates the damping in conductors. However, this system possesses a distinctive feature in the bandstructure that minimizes the density of states at the Fermi energy n(EF). These findings provide the theoretical framework by which such ultra-low damping can be achieved in metallic ferromagnets and may enable a new class of experiments where ultra-low damping can be combined with a charge current. Half-metallic Heusler compounds by definition have a bandgap in one of the spin channels at the Fermi energy. This feature can also lead to exceptionally low values of the damping parameter. Our results show a strong correlation of the damping with the order parameter in Co2MnGe. Finally, I will provide an overview of the recent advances in achieving low damping in thin film Heusler compounds.

Hard ceramic coatings: an experimental study on a novel damping treatment

NASA Astrophysics Data System (ADS)

Patsias, Sophoclis; Tassini, Nicola; Stanway, Roger

2004-07-01

This paper describes a novel damping treatment, namely hard ceramic coatings. These materials can be applied on almost any surface (internal or external) of a component. Their effect is the significant reduction of vibration levels and hence the extension of life expectancy of the component. The damping features of air-plasma-sprayed ceramic coatings (for example amplitude dependence, influence of initial amplitude) are discussed and the experimental procedure employed for testing and characterising such materials is also described. This test procedure is based around a custom-developed rig that allows one to measure the damping (internal friction) of specimens at controlled frequencies, strain amplitudes and, if required, various temperatures. A commonly used Thermal Barrier Coating, Yttria Stabilised Zirconia (8%), is used to demonstrate the above mentioned features. The damping effectiveness of this coating is then compared against two established damping treatments: polymer Free Layer Damping (FLD) and Constrained Layer Damping (CLD). The paper discusses the major issues in characterising ceramic damping coatings and their damping effectiveness when compared against the "traditional" approaches. Finally, the paper concludes with suggestions for further research.

Nonlocal Gilbert damping tensor within the torque-torque correlation model

NASA Astrophysics Data System (ADS)

Thonig, Danny; Kvashnin, Yaroslav; Eriksson, Olle; Pereiro, Manuel

2018-01-01

An essential property of magnetic devices is the relaxation rate in magnetic switching, which depends strongly on the damping in the magnetization dynamics. It was recently measured that damping depends on the magnetic texture and, consequently, is a nonlocal quantity. The damping enters the Landau-Lifshitz-Gilbert equation as the phenomenological Gilbert damping parameter α , which does not, in a straightforward formulation, account for nonlocality. Efforts were spent recently to obtain Gilbert damping from first principles for magnons of wave vector q . However, to the best of our knowledge, there is no report about real-space nonlocal Gilbert damping αi j. Here, a torque-torque correlation model based on a tight-binding approach is applied to the bulk elemental itinerant magnets and it predicts significant off-site Gilbert damping contributions, which could be also negative. Supported by atomistic magnetization dynamics simulations, we reveal the importance of the nonlocal Gilbert damping in atomistic magnetization dynamics. This study gives a deeper understanding of the dynamics of the magnetic moments and dissipation processes in real magnetic materials. Ways of manipulating nonlocal damping are explored, either by temperature, materials doping, or strain.

Experimental Determination of Aerodynamic Damping in a Three-Stage Transonic Axial-Flow Compressor. Degree awarded by Case Western Reserve Univ.

NASA Technical Reports Server (NTRS)

Newman, Frederick A.

1988-01-01

Rotor blade aerodynamic damping is experimentally determined in a three-stage transonic axial flow compressor having design aerodynamic performance goals of 4.5:1 pressure ratio and 65.5 lbm/sec weight flow. The combined damping associated with each mode is determined by a least squares fit of a single degree of freedom system transfer function to the nonsynchronous portion of the rotor blade strain gauge output power spectra. The combined damping consists of aerodynamic and structural and mechanical damping. The aerodynamic damping varies linearly with the inlet total pressure for a given equivalent speed, equivalent mass flow, and pressure ratio while structural and mechanical damping are assumed to be constant. The combined damping is determined at three inlet total pressure levels to obtain the aerodynamic damping. The third stage rotor blade aerodynamic damping is presented and discussed for 70, 80, 90, and 100 percent design equivalent speed. The compressor overall performance and experimental Campbell diagrams for the third stage rotor blade row are also presented.

Structural damage identification using damping: a compendium of uses and features

NASA Astrophysics Data System (ADS)

Cao, M. S.; Sha, G. G.; Gao, Y. F.; Ostachowicz, W.

2017-04-01

The vibration responses of structures under controlled or ambient excitation can be used to detect structural damage by correlating changes in structural dynamic properties extracted from responses with damage. Typical dynamic properties refer to modal parameters: natural frequencies, mode shapes, and damping. Among these parameters, natural frequencies and mode shapes have been investigated extensively for their use in damage characterization by associating damage with reduction in local stiffness of structures. In contrast, the use of damping as a dynamic property to represent structural damage has not been comprehensively elucidated, primarily due to the complexities of damping measurement and analysis. With advances in measurement technologies and analysis tools, the use of damping to identify damage is becoming a focus of increasing attention in the damage detection community. Recently, a number of studies have demonstrated that damping has greater sensitivity for characterizing damage than natural frequencies and mode shapes in various applications, but damping-based damage identification is still a research direction ‘in progress’ and is not yet well resolved. This situation calls for an overall survey of the state-of-the-art and the state-of-the-practice of using damping to detect structural damage. To this end, this study aims to provide a comprehensive survey of uses and features of applying damping in structural damage detection. First, we present various methods for damping estimation in different domains including the time domain, the frequency domain, and the time-frequency domain. Second, we investigate the features and applications of damping-based damage detection methods on the basis of two predominant infrastructure elements, reinforced concrete structures and fiber-reinforced composites. Third, we clarify the influential factors that can impair the capability of damping to characterize damage. Finally, we recommend future research directions for advancing damping-based damage detection. This work holds the promise of (a) helping researchers identify crucial components in damping-based damage detection theories, methods, and technologies, and (b) leading practitioners to better implement damping-based structural damage identification.

Thermoelastic Damping in FGM Nano-Electromechanical System in Axial Vibration Based on Eringen Nonlocal Theory

NASA Astrophysics Data System (ADS)

Rahimi, Z.; Rashahmadi, S.

2017-11-01

The thermo-elastic damping is a dominant source of internal damping in micro-electromechanical systems (MEMS) and nano-electromechanical systems (NEMS). The internal damping cannot neither be controlled nor minimized unless either mechanical or geometrical properties are changed. Therefore, a novel FGMNEM system with a controllable thermo-elastic damping of axial vibration based on Eringen nonlocal theory is considered. The effects of different parameter like the gradient index, nonlocal parameter, length of nanobeam and ambient temperature on the thermo-elastic damping quality factor are presented. It is shown that the thermo-elastic damping can be controlled by changing different parameter.

Analysis of passive damping in thick composite structures

NASA Technical Reports Server (NTRS)

Saravanos, D. A.

1993-01-01

Computational mechanics for the prediction of damping and other dynamic characteristics in composite structures of general thicknesses and laminations are presented. Discrete layer damping mechanics that account for the representation of interlaminar shear effects in the material are summarized. Finite element based structural mechanics for the analysis of damping are described, and a specialty finite element is developed. Applications illustrate the quality of the discrete layer damping mechanics in predicting the damped dynamic characteristics of composite structures with thicker sections and/or laminate configurations that induce interlaminar shear. The results also illustrate and quantify the significance of interlaminar shear damping in such composite structures.

Influence of Button mushroom (Agaricus bisporus) on quality and refrigerated storage stability of patties prepared from sutchi catfish (Pangasius hypophthalmus).

PubMed

Nayak, Prakash Chandra; Raju, C V; Lakshmisha, I P; Singh, Rajkumar Ratankumar; Sofi, Faisal Rashid

2015-06-01

The ability of button mushroom (Agaricus bisporus) in changing physical, chemical, microbial and sensory properties of fish patties prepared from sutchi catfish (Pangasius hypophthalmus) was investigated. Two batches of fresh patties were prepared, one batch was treated with 15 % button mushroom (TP) and other batch was a control (CP) without mushroom. The patties were packed in polythene bags and stored under refrigerated condition (6 ± 2 ºC) without adding any preservatives for the estimation of storage stability. The analyses of patties were conducted at regular intervals of 3 days. The results showed that, Peroxide value, Thiobarbituric acid value, Free fatty acids increased significantly in CP at the end of 12 days whereas the TP was within the acceptable limit up to 16 days. Total volatile base nitrogen and Trimethylamine nitrogen also showed a similar trend. The Total plate count and Aerobic spore formers showed an increasing trend in CP when compared to TP. The sensory scores showed that the overall acceptability of CP were lower than TP, which was acceptable even after 16 days of storage. The present study showed that, the quality and storage stability of TP were observed to be in good condition up to 16 days and started deteriorating 20th day onwards, whereas the CP were acceptable only up to 12 days. Therefore it can be recommended that, addition of 15 % of button mushroom to sutchi catfish patty not only increases the nutritional quality but also increases the shelf life of patties under refrigerated storage.

What Kind of Capsule Endoscope Is Suitable for a Controllable Self-Propelling Capsule Endoscope? Experimental Study Using a Porcine Stomach Model for Clinical Application (with Videos)

PubMed Central

Ota, Kazuhiro; Nouda, Sadaharu; Takeuchi, Toshihisa; Iguchi, Munetaka; Kojima, Yuichi; Kuramoto, Takanori; Inoue, Takuya; Shindo, Yasunori; Uesugi, Kenshiro; Fujito, Yoshiaki; Nishihara, Hironori; Ohtsuka, Naotake; Higuchi, Kazuhide

2015-01-01

Background We have been developing the Self-Propelling Capsule Endoscope (SPCE) that allows for controllability from outside of the body and real-time observation. What kind of capsule endoscope (CE) is suitable for a controllable SPCE is unclear and a very critical point for clinical application. We compared observing ability of three kinds of SPCEs with different viewing angles and frame rates. Methods Eleven buttons were sewed in an excised porcine stomach. Four examiners controlled the SPCE using PillCamSB2, -ESO2, and -COLON2 (Given Imaging Ltd., Israel), for 10 minutes each with the aim of detecting as many buttons and examining them as closely as possible. The ability to find lesions was assessed based on the number of detected buttons. The SPCE-performance score (SPS) was used to evaluate the ability to examine the lesions in detail. Results The SPCE-ESO2, -COLON2, and -SB2 detected 11 [interquartile range (IQR): 0], 10.5 (IQR, 0.5), and 8 (IQR, 1.0) buttons, respectively. The SPCE-ESO2 and -COLON2 had a significantly better ability to detect lesions than the -SB2 (p < 0.05). The SPCE-ESO2, -COLON2, and -SB2 had significantly different SPS values of 22 (IQR, 0), 16.5 (IQR, 1.5), and 14 (IQR, 1.0), respectively (p < 0.05 for all comparisons; SPCE-SB2 vs. -ESO2, -SB2 vs. -COLON2, and -ESO2 vs. -COLON2). Conclusions PillCamESO2 is most suitable in different three CEs for SPCE for examining lesions in detail of the stomach. PMID:26447694

Limb-kinetic apraxia affects activities of daily living in Parkinson’s disease: a multi-center study

PubMed Central

Foki, T.; Vanbellingen, T.; Lungu, C.; Pirker, W.; Bohlhalter, S.; Nyffeler, T.; Kraemmer, J.; Haubenberger, D.; Fischmeister, F. Ph. S.; Auff, E.; Hallett, M.; Beisteiner, R.

2017-01-01

Background and purpose Impaired dexterity (fine hand movements) is often present in Parkinson’s disease (PD), even at early to moderate disease stages. It has a detrimental impact on activities of daily living (ADL) such as buttoning, contributing to reduced quality of life. Limb-kinetic apraxia, a loss of the ability to make precise, independent but coordinated finger and hand movements, may contribute to impaired dexterity even more than bradykinesia per se. However, the impact of limb-kinetic apraxia on ADL remains controversial. Our aim was to identify the strongest predictor of buttoning and unbuttoning in PD. It was hypothesized that coin rotation (a surrogate of limb-kinetic apraxia) represents the most important determinant. Methods Sixty-four right-handed, early to moderate PD patients were recruited from three movement disorder centers (Hoehn and Yahr stages 1–3). Buttoning, unbuttoning and coin rotation (right and left hand) represented the target tasks. Motor impairment was assessed according to the Unified Parkinson’s Disease Rating Scale. Results Multiple linear regression analysis showed that coin rotation with the right hand was the only significant predictor of buttoning (P < 0.001) and unbuttoning (P = 0.002). Notably, measures of bradykinesia or overall motor impairment did not represent significant predictors. Conclusions Constituting the novel key finding, limb-kinetic apraxia seems to be particularly relevant for ADL requiring dexterity skills in PD, even at early to moderate disease stages. Our results prompt research into the pathophysiological background and therapeutic options to treat limb-kinetic apraxia. The simple coin rotation test provides valuable information about ADL-related dexterity skills. PMID:27132653

What Kind of Capsule Endoscope Is Suitable for a Controllable Self-Propelling Capsule Endoscope? Experimental Study Using a Porcine Stomach Model for Clinical Application (with Videos).

PubMed

Ota, Kazuhiro; Nouda, Sadaharu; Takeuchi, Toshihisa; Iguchi, Munetaka; Kojima, Yuichi; Kuramoto, Takanori; Inoue, Takuya; Shindo, Yasunori; Uesugi, Kenshiro; Fujito, Yoshiaki; Nishihara, Hironori; Ohtsuka, Naotake; Higuchi, Kazuhide

2015-01-01

We have been developing the Self-Propelling Capsule Endoscope (SPCE) that allows for controllability from outside of the body and real-time observation. What kind of capsule endoscope (CE) is suitable for a controllable SPCE is unclear and a very critical point for clinical application. We compared observing ability of three kinds of SPCEs with different viewing angles and frame rates. Eleven buttons were sewed in an excised porcine stomach. Four examiners controlled the SPCE using PillCamSB2, -ESO2, and -COLON2 (Given Imaging Ltd., Israel), for 10 minutes each with the aim of detecting as many buttons and examining them as closely as possible. The ability to find lesions was assessed based on the number of detected buttons. The SPCE-performance score (SPS) was used to evaluate the ability to examine the lesions in detail. The SPCE-ESO2, -COLON2, and -SB2 detected 11 [interquartile range (IQR): 0], 10.5 (IQR, 0.5), and 8 (IQR, 1.0) buttons, respectively. The SPCE-ESO2 and -COLON2 had a significantly better ability to detect lesions than the -SB2 (p < 0.05). The SPCE-ESO2, -COLON2, and -SB2 had significantly different SPS values of 22 (IQR, 0), 16.5 (IQR, 1.5), and 14 (IQR, 1.0), respectively (p < 0.05 for all comparisons; SPCE-SB2 vs. -ESO2, -SB2 vs. -COLON2, and -ESO2 vs. -COLON2). PillCamESO2 is most suitable in different three CEs for SPCE for examining lesions in detail of the stomach.

Meal Microstructure Characterization from Sensor-Based Food Intake Detection.

PubMed

Doulah, Abul; Farooq, Muhammad; Yang, Xin; Parton, Jason; McCrory, Megan A; Higgins, Janine A; Sazonov, Edward

2017-01-01

To avoid the pitfalls of self-reported dietary intake, wearable sensors can be used. Many food ingestion sensors offer the ability to automatically detect food intake using time resolutions that range from 23 ms to 8 min. There is no defined standard time resolution to accurately measure ingestive behavior or a meal microstructure. This paper aims to estimate the time resolution needed to accurately represent the microstructure of meals such as duration of eating episode, the duration of actual ingestion, and number of eating events. Twelve participants wore the automatic ingestion monitor (AIM) and kept a standard diet diary to report their food intake in free-living conditions for 24 h. As a reference, participants were also asked to mark food intake with a push button sampled every 0.1 s. The duration of eating episodes, duration of ingestion, and number of eating events were computed from the food diary, AIM, and the push button resampled at different time resolutions (0.1-30s). ANOVA and multiple comparison tests showed that the duration of eating episodes estimated from the diary differed significantly from that estimated by the AIM and the push button ( p -value <0.001). There were no significant differences in the number of eating events for push button resolutions of 0.1, 1, and 5 s, but there were significant differences in resolutions of 10-30s ( p -value <0.05). The results suggest that the desired time resolution of sensor-based food intake detection should be ≤5 s to accurately detect meal microstructure. Furthermore, the AIM provides more accurate measurement of the eating episode duration than the diet diary.

Meal Microstructure Characterization from Sensor-Based Food Intake Detection

PubMed Central

Doulah, Abul; Farooq, Muhammad; Yang, Xin; Parton, Jason; McCrory, Megan A.; Higgins, Janine A.; Sazonov, Edward

2017-01-01

To avoid the pitfalls of self-reported dietary intake, wearable sensors can be used. Many food ingestion sensors offer the ability to automatically detect food intake using time resolutions that range from 23 ms to 8 min. There is no defined standard time resolution to accurately measure ingestive behavior or a meal microstructure. This paper aims to estimate the time resolution needed to accurately represent the microstructure of meals such as duration of eating episode, the duration of actual ingestion, and number of eating events. Twelve participants wore the automatic ingestion monitor (AIM) and kept a standard diet diary to report their food intake in free-living conditions for 24 h. As a reference, participants were also asked to mark food intake with a push button sampled every 0.1 s. The duration of eating episodes, duration of ingestion, and number of eating events were computed from the food diary, AIM, and the push button resampled at different time resolutions (0.1–30s). ANOVA and multiple comparison tests showed that the duration of eating episodes estimated from the diary differed significantly from that estimated by the AIM and the push button (p-value <0.001). There were no significant differences in the number of eating events for push button resolutions of 0.1, 1, and 5 s, but there were significant differences in resolutions of 10–30s (p-value <0.05). The results suggest that the desired time resolution of sensor-based food intake detection should be ≤5 s to accurately detect meal microstructure. Furthermore, the AIM provides more accurate measurement of the eating episode duration than the diet diary. PMID:28770206

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Wenkai; Ghosh, Priyarshini; Harrison, Mark

The performance of traditional Hornyak buttons and two proposed variants for fast-neutron hodoscope applications was evaluated using Geant4. The Hornyak button is a ZnS(Ag)-based device previously deployed at the Idaho National Laboratory's TRansient REActor Test Facility (better known as TREAT) for monitoring fast neutrons emitted during pulsing of fissile fuel samples. Past use of these devices relied on pulse-shape discrimination to reduce the significant levels of background Cherenkov radiation. Proposed are two simple designs that reduce the overall light guide mass (here, polymethyl methacrylate or PMMA), employ silicon photomultipliers (SiPMs), and can be operated using pulse-height discrimination alone to eliminatemore » background noise to acceptable levels. Geant4 was first used to model a traditional Hornyak button, and for assumed, hodoscope-like conditions, an intrinsic efficiency of 0.35% for mono-directional fission neutrons was predicted. The predicted efficiency is in reasonably good agreement with experimental data from the literature and, hence, served to validate the physics models and approximations employed. Geant4 models were then developed to optimize the materials and geometries of two alternatives to the Hornyak button, one based on a homogeneous mixture of ZnS(Ag) and PMMA, and one based on alternating layers of ZnS(Ag) and PMMA oriented perpendicular to the incident neutron beam. For the same radiation environment, optimized, 5-cm long (along the beam path) devices of the homogeneous and layered designs were predicted to have efficiencies of approximately 1.3% and 3.3%, respectively. For longer devices, i.e., lengths larger than 25 cm, these efficiencies were shown to peak at approximately 2.2% and 5.9%, respectively. Furthermore, both designs were shown to discriminate Cherenkov noise intrinsically by using an appropriate pulse-height discriminator level, i.e., pulse-shape discrimination is not needed for these devices.« less

Magnetic damping phenomena in ferromagnetic thin-films and multilayers

NASA Astrophysics Data System (ADS)

Azzawi, S.; Hindmarch, A. T.; Atkinson, D.

2017-11-01

Damped ferromagnetic precession is an important mechanism underpinning the magnetisation processes in ferromagnetic materials. In thin-film ferromagnets and ferromagnetic/non-magnetic multilayers, the role of precession and damping can be critical for spintronic device functionality and as a consequence there has been significant research activity. This paper presents a review of damping in ferromagnetic thin-films and multilayers and collates the results of many experimental studies to present a coherent synthesis of the field. The terms that are used to define damping are discussed with the aim of providing consistent definitions for damping phenomena. A description of the theoretical basis of damping is presented from early developments to the latest discussions of damping in ferromagnetic thin-films and multilayers. An overview of the time and frequency domain methods used to study precessional magnetisation behaviour and damping in thin-films and multilayers is also presented. Finally, a review of the experimental observations of magnetic damping in ferromagnetic thin-films and multilayers is presented with the most recent explanations. This brings together the results from many studies and includes the effects of ferromagnetic film thickness, the effects of composition on damping in thin-film ferromagnetic alloys, the influence of non-magnetic dopants in ferromagnetic films and the effects of combining thin-film ferromagnets with various non-magnetic layers in multilayered configurations.

A harmonic oscillator having “volleyball damping”

NASA Astrophysics Data System (ADS)

Mickens, R. E.; Oyedeji, K.; Rucker, S. A.

2006-05-01

Volleyball damping corresponds to linear damping up to a certain critical velocity, with zero damping above this value. The dynamics of a linear harmonic oscillator is investigated with this damping mechanism.

Experimental study on the damping of FAST cabin suspension system

NASA Astrophysics Data System (ADS)

Li, Hui; Sun, Jing-hai; Zhang, Xin-yu; Zhu, Wen-bai; Pan, Gao-feng; Yang, Qing-ge

2012-09-01

The focus cabin suspension of the FAST telescope has structurally weak-stiffness dynamics with low damping performance, which makes it quite sensitive to wind-induced vibrations. A reasonable estimation about the damping is very important for the control performance evaluation of the prototype. It is a quite difficult task as the telescope is no at available yet. In the paper, a preliminary analysis is first made on the aerodynamic damping. Then a series of experimental models are tested for measuring the total damping. The scales of these models range from 10m to 50m in diameter while 6 test parameters are specially designed to check the damping sensitivity. The Ibrahim time domain (ITD) method is employed to identify the damping from the measured cabin response. The identification results indicate that the lowest damping ratio of the models is about 0.2%~0.4%. Friction-type cabin-cable joint seems to have main influence on the system damping.

Experimental Spin Testing of Integrally Damped Composite Plates

NASA Technical Reports Server (NTRS)

Kosmatka, John

1998-01-01

The experimental behavior of spinning laminated composite pretwisted plates (turbo-fan blade-like) with small (less than 10% by volume) integral viscoelastic damping patches was investigated at NASA-Lewis Research Center. Ten different plate sets were experimentally spin tested and the resulting data was analyzed. The first-four plate sets investigated tailoring patch locations and definitions to damp specific modes on spinning flat graphite/epoxy plates as a function of rotational speed. The remaining six plate sets investigated damping patch size and location on specific modes of pretwisted (30 degrees) graphite/epoxy plates. The results reveal that: (1) significant amount of damping can be added using a small amount of damping material, (2) the damped plates experienced no failures up to the tested 28,000 g's and 750,000 cycles, (3) centrifugal loads caused an increase in bending frequencies and corresponding reductions in bending damping levels that are proportional to the bending stiffness increase, and (4) the centrifugal loads caused a decrease in torsion natural frequency and increase in damping levels of pretwisted composite plates.

Measurements of long-range enhanced collisional velocity drag through plasma wave damping

NASA Astrophysics Data System (ADS)

Affolter, M.; Anderegg, F.; Dubin, D. H. E.; Driscoll, C. F.

2018-05-01

We present damping measurements of axial plasma waves in magnetized, multispecies ion plasmas. At high temperatures T ≳ 10-2 eV, collisionless Landau damping dominates, whereas, at lower temperatures T ≲ 10-2 eV, the damping arises from interspecies collisional drag, which is dependent on the plasma composition and scales roughly as T-3 /2 . This drag damping is proportional to the rate of parallel collisional slowing, and is found to exceed classical predictions of collisional drag damping by as much as an order of magnitude, but agrees with a new collision theory that includes long-range collisions. Centrifugal mass separation and collisional locking of the species occur at ultra-low temperatures T ≲ 10-3 eV, which reduce the drag damping from the T-3 /2 collisional scaling. These mechanisms are investigated by measuring the damping of higher frequency axial modes, and by measuring the damping in plasmas with a non-equilibrium species profile.

Flux-driven algebraic damping of m = 1 diocotron mode

NASA Astrophysics Data System (ADS)

Chim, Chi Yung; O'Neil, Thomas

2015-11-01

Recent experiments with pure electron plasmas in a Malmberg-Penning trap have observed the algebraic damping of m = 1 diocotron modes. Transport due to small field asymmetries produce a low density halo of electrons moving radially outward from the plasma core, and the mode damping begins when the halo reaches the resonant radius rres, where f = mfE × B (rres) . The damping rate is proportional to the flux of halo particles through the resonant layer. The damping is related to, but distinct from spatial Landau damping, in which a linear wave-particle resonance produces exponential damping. This poster explains with analytic theory and simulations the new algebraic damping due to both mobility and diffusive fluxes. As electrons are swept around the ``cat's eye'' orbits of resonant wave-particle interaction, they form a dipole (m = 1) density distribution, and the electric field from this distribution produces an E × B drift of the core back to the axis, i.e. damps the m = 1 mode. Supported by National Science Foundation Grant PHY-1414570.

Observations of Excitation and Damping of Transversal Oscillations in Coronal Loops by AIA/SDO

NASA Astrophysics Data System (ADS)

Abedini, A.

2018-02-01

The excitation and damping of the transversal coronal loop oscillations and quantitative relation between damping time, damping property (damping time per period), oscillation amplitude, dissipation mechanism and the wake phenomena are investigated. The observed time series data with the Atmospheric Imaging Assembly (AIA) telescope on NASA's Solar Dynamics Observatory (SDO) satellite on 2015 March 2, consisting of 400 consecutive images with 12 s cadence in the 171 Å pass band is analyzed for evidence of transversal oscillations along the coronal loops by the Lomb-Scargle periodgram. In this analysis signatures of transversal coronal loop oscillations that are damped rapidly were found with dominant oscillation periods in the range of P=12.25 - 15.80 min. Also, damping times and damping properties of the transversal coronal loop oscillations at dominant oscillation periods are estimated in the range of {τd=11.76} - {21.46} min and {τd/P=0.86} - {1.49}, respectively. The observational results of this analysis show that damping properties decrease slowly with increasing amplitude of the oscillation, but the periods of the oscillations are not sensitive functions of the amplitude of the oscillations. The order of magnitude of the damping properties and damping times are in good agreement with previous findings and the theoretical prediction for damping of kink mode oscillations by the dissipation mechanism. Furthermore, oscillations of the loop segments attenuate with time roughly as t^{-α} and the magnitude values of α for 30 different segments change from 0.51 to 0.75.

Logic operations based on magnetic-vortex-state networks.

PubMed

Jung, Hyunsung; Choi, Youn-Seok; Lee, Ki-Suk; Han, Dong-Soo; Yu, Young-Sang; Im, Mi-Young; Fischer, Peter; Kim, Sang-Koog

2012-05-22

Logic operations based on coupled magnetic vortices were experimentally demonstrated. We utilized a simple chain structure consisting of three physically separated but dipolar-coupled vortex-state Permalloy disks as well as two electrodes for application of the logical inputs. We directly monitored the vortex gyrations in the middle disk, as the logical output, by time-resolved full-field soft X-ray microscopy measurements. By manipulating the relative polarization configurations of both end disks, two different logic operations are programmable: the XOR operation for the parallel polarization and the OR operation for the antiparallel polarization. This work paves the way for new-type programmable logic gates based on the coupled vortex-gyration dynamics achievable in vortex-state networks. The advantages are as follows: a low-power input signal by means of resonant vortex excitation, low-energy dissipation during signal transportation by selection of low-damping materials, and a simple patterned-array structure.

Manifold, bus support and coupling arrangement for solid oxide fuel cells

DOEpatents

Parry, G.W.

1988-04-21

Individual, tubular solid oxide fuel cells (SOFCs) are assembled into bundles called a module within a housing, with a plurality of modules arranged end-to-end in a linear, stacked configuration called a string. A common set of piping comprised of a suitable high temperature resistant material (1) provides fuel and air to each module housing, (2) serves as electrically conducting buses, and (3) provides structural support for a string of SOFC modules. Ceramic collars are used to connect fuel and air inlet piping to each of the electrodes in an SOFC module and provide (1) electrical insulation for the current carrying bus bars and gas manifolds, (2) damping for the fuel and air inlet piping, and (3) proper spacing between the fuel and air inlet piping to prevent contact between these tubes and possible damage to the SOFC. 11 figs.

Optomechanical proposal for monitoring microtubule mechanical vibrations

NASA Astrophysics Data System (ADS)

Barzanjeh, Sh.; Salari, V.; Tuszynski, J. A.; Cifra, M.; Simon, C.

2017-07-01

Microtubules provide the mechanical force required for chromosome separation during mitosis. However, little is known about the dynamic (high-frequency) mechanical properties of microtubules. Here, we theoretically propose to control the vibrations of a doubly clamped microtubule by tip electrodes and to detect its motion via the optomechanical coupling between the vibrational modes of the microtubule and an optical cavity. In the presence of a red-detuned strong pump laser, this coupling leads to optomechanical-induced transparency of an optical probe field, which can be detected with state-of-the art technology. The center frequency and line width of the transparency peak give the resonance frequency and damping rate of the microtubule, respectively, while the height of the peak reveals information about the microtubule-cavity field coupling. Our method opens the new possibilities to gain information about the physical properties of microtubules, which will enhance our capability to design physical cancer treatment protocols as alternatives to chemotherapeutic drugs.

Modal Analysis of Embedded Passive Damping Materials in Composite Plates with Different Orientations

NASA Technical Reports Server (NTRS)

Kehoe, Michael; Kolkailah, Faysal A.; Elghandour, Eltahry I.

1998-01-01

This report presents an experimental and numerical investigation of the free vibration of cantilevered composite plates with and without passive damping. A total of seven composite material plates are considered. The lay-up sequences for the two plates without damping are [90/90/0/0], and [90/0/90/0]; the other five plates are the same as the first two with two embedded layers of passive damping material. The passive damping material is embedded at different locations in the plate with orientation [90/0/90/0],. The damping material employed is a 3M material (SJ-2015 ISD 112) with peak damping properties in the ambient temperature range (32 F to 140 F). The composite material used is a carbon fiber (977-2)/epoxy resin (IM7). The effect of the passive damping system employed in this study for the composite plates are discussed. Modal testing is performed on these plates to determine resonant frequencies, amplitude and mode shape information. Numerical results are obtained using COSMOS/M software for the plates without damping. The experimental and numerical results are in very good agreement for different laminated plates without damping layers.

[Textural research on the origin and evolution of the"theory of drying dampness"and its initiator].

PubMed

Zhou, X M; Hu, J P

2016-07-28

There are two different records, namely,"vulnerability to dampness in autumn"and"dryness prevailing"in autumn, in the Neijing ( Inner Canon ). In the Jin and Yuan Dynasties, Liu Wansu supplemented the pathogenesis of dryness pathogen, whereas Wang Andao explained the contradictory records in the Neijing . In the Qing Dynasty, Yu Chang definitely challenged the theory"vulnerability to dampness in autumn"of the Neijing ,triggering a debate on the recognition of"drying dampness". In fact, Yu Guopei was the initiator of"theory of drying dampness", who discussed the nature of Yin and Yang of"drying dampness"based on the laws of correspondence between human body and natural environment, elucidating that drying dampness should be the root of both exogenous disease and internal damage, and elaborating the etiology and pathogenesis of"drying dampness", the diagnosis and the nature of the drugs for drying dampness. Shi Shoutang inherited Yu's theory and made a further development. In modern times, some scholars advocated that"drying dampness"should be consideredalong with Yin and Yang, superficies and interior, excess and deficiency, cold and heat, as the guiding principle for syndrome differentiation.

The Joint Damping Experiment (JDX)

NASA Technical Reports Server (NTRS)

Folkman, Steven L.; Bingham, Jeff G.; Crookston, Jess R.; Dutson, Joseph D.; Ferney, Brook D.; Ferney, Greg D.; Rowsell, Edwin A.

1997-01-01

The Joint Damping Experiment (JDX), flown on the Shuttle STS-69 Mission, is designed to measure the influence of gravity on the structural damping of a high precision three bay truss. Principal objectives are: (1) Measure vibration damping of a small-scale, pinjointed truss to determine how pin gaps give rise to gravity-dependent damping rates; (2) Evaluate the applicability of ground and low-g aircraft tests for predicting on-orbit behavior; and (3) Evaluate the ability of current nonlinear finite element codes to model the dynamic behavior of the truss. Damping of the truss was inferred from 'Twang' tests that involve plucking the truss structure and recording the decay of the oscillations. Results are summarized as follows. (1) Damping, rates can change by a factor of 3 to 8 through changing the truss orientation; (2) The addition of a few pinned joints to a truss structure can increase the damping by a factor as high as 30; (3) Damping is amplitude dependent; (4) As gravity induced preloads become large (truss long axis perpendicular to gravity vector) the damping is similar to non-pinjointed truss; (5) Impacting in joints drives higher modes in structure; (6) The torsion mode disappears if gravity induced preloads are low.

DAMPING OF MAGNETOHYDRODYNAMIC TURBULENCE IN PARTIALLY IONIZED PLASMA: IMPLICATIONS FOR COSMIC RAY PROPAGATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Siyao; Yan, Huirong; Lazarian, A., E-mail: syxu@pku.edu.cn, E-mail: huirong.yan@desy.de, E-mail: lazarian@astro.wisc.edu

2016-08-01

We study the damping processes of both incompressible and compressible magnetohydrodynamic (MHD) turbulence in a partially ionized medium. We start from the linear analysis of MHD waves, applying both single-fluid and two-fluid treatments. The damping rates derived from the linear analysis are then used in determining the damping scales of MHD turbulence. The physical connection between the damping scale of MHD turbulence and the cutoff boundary of linear MHD waves is investigated. We find two branches of slow modes propagating in ions and neutrals, respectively, below the damping scale of slow MHD turbulence, and offer a thorough discussion of theirmore » propagation and dissipation behavior. Our analytical results are shown to be applicable in a variety of partially ionized interstellar medium (ISM) phases and the solar chromosphere. The importance of neutral viscosity in damping the Alfvenic turbulence in the interstellar warm neutral medium and the solar chromosphere is demonstrated. As a significant astrophysical utility, we introduce damping effects to the propagation of cosmic rays in partially ionized ISM. The important role of turbulence damping in both transit-time damping and gyroresonance is identified.« less

Material Damping Experiments at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Levine, Marie; White, Christopher

2003-01-01

A unique experimental facility has been designed to measure damping of materials at cryogenic temperatures. The test facility pays special attention to removing other sources of damping in the measurement by avoiding frictional interfaces, decoupling the test specimen from the support system, and by using a non-contacting measurement device; Damping data is obtained for materials (AI, GrEp, Be, Fused Quartz), strain amplitudes (less than 10-6 ppm), frequencies (20Hz-330Hz) and temperatures (20K-293K) relevant to future precision optical space missions. The test data shows a significant decrease in viscous damping at cryogenic temperatures and can be as low as 10-4%, but the amount of the damping decrease is a function of frequency and material. Contrary to the other materials whose damping monotonically decreased with temperature, damping of Fused Quartz increased substantially at cryo, after reaching a minimum at around l50 K. The damping is also shown to be insensitive to strain for low strain levels. At room temperatures, the test data correlates well to the analytical predictions of the Zener damping model. Discrepancies at cryogenic temperatures between the model predictions and the test data are observed.

A Novel Damping Mechanism for Diocotron Modes

NASA Astrophysics Data System (ADS)

Chim, Chi Yung; O'Neil, Thomas M.

2014-10-01

Recent experiments with pure electron plasmas in a Malmberg-Penning trap have observed the algebraic damping of m = 1 and m = 2 diocotron modes. Transport due to small field asymmetries produces a low density halo of electrons moving radially outward from the plasma core, and the mode damping begins when the halo reaches the resonant radius, where f = mfE × B (r) . The damping rate is proportional to the flux of halo particles through the resonant layer. The damping is related to, but distinct from spatial Landau damping, in which a linear wave-particle resonance produces exponential damping. This poster explains with analytic theory and simulations the new algebraic damping due to both mobility and diffusive fluxes. The damping is due to transfer of canonical angular momentum from the mode to halo particles, as they are swept around the ``cat's eye'' orbits of resonant wave-particle interaction. Another picture is that the electrons in the resonant layer form a dipole (m = 1) or quadrupole (m = 2) density distribution, and the electric field for this distribution produces E × B drifts that symmetrizes the core and damps the mode. Supported by NSF/DOE Partnership Grants PHY-0903877 and DE-SC0002451.

Dynamical shift condition for unequal mass black hole binaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, Doreen; Grigsby, Jason; Bruegmann, Bernd

Certain numerical frameworks used for the evolution of binary black holes make use of a gamma driver, which includes a damping factor. Such simulations typically use a constant value for damping. However, it has been found that very specific values of the damping factor are needed for the calculation of unequal mass binaries. We examine carefully the role this damping plays and provide two explicit, nonconstant forms for the damping to be used with mass ratios further from one. Our analysis of the resultant waveforms compares well against the constant damping case.

Squeeze-Film Air Damping of a Five-Axis Electrostatic Bearing for Rotary Micromotors

PubMed Central

Wang, Shunyue; Han, Fengtian; Sun, Boqian; Li, Haixia

2017-01-01

Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeeze-film air damping results of an electrostatic bearing for use in a rotary high-speed micromotor. It is shown that the boundary condition to solve the three-dimensional Reynolds equation, which governs the squeeze-film damping in the air gap between the rotor and its surrounding stator sealed in a three-layer evacuated cavity, behaves with strong cross-axis coupling characteristics. To accurately characterize the damping effect, a set of multiphysics finite-element simulations are performed by computing both the rotor velocity and the distribution of the viscous damping force acting on the rotor. The damping characteristics varying with several key structure parameters are simulated and discussed to optimize the device structure for desirable rotor dynamics. An electrical measurement method is also proposed and applied to validate the numerical results of the damping coefficients experimentally. Given that the frequency response of the electric bearing is critically dependent on the damping coefficients at atmospheric pressure, a solution to the air-film damping measurement problem is presented by taking approximate curve fitting of multi-axis experimental frequency responses. The measured squeeze-film damping coefficients for the five-axis electric bearing agrees well with the numerical solutions. This indicates that numerical multiphysics simulation is an effective method to accurately examine the air-film damping effect for complex device geometry and arbitrary boundary condition. The accurate damping coefficients obtained by FEM simulation will greatly simplify the design of the five-axis bearing control system and facilitate the initial suspension test of the rotor for various micromotor devices. PMID:28505089

Squeeze-Film Air Damping of a Five-Axis Electrostatic Bearing for Rotary Micromotors.

PubMed

Wang, Shunyue; Han, Fengtian; Sun, Boqian; Li, Haixia

2017-05-13

Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeeze-film air damping results of an electrostatic bearing for use in a rotary high-speed micromotor. It is shown that the boundary condition to solve the three-dimensional Reynolds equation, which governs the squeeze-film damping in the air gap between the rotor and its surrounding stator sealed in a three-layer evacuated cavity, behaves with strong cross-axis coupling characteristics. To accurately characterize the damping effect, a set of multiphysics finite-element simulations are performed by computing both the rotor velocity and the distribution of the viscous damping force acting on the rotor. The damping characteristics varying with several key structure parameters are simulated and discussed to optimize the device structure for desirable rotor dynamics. An electrical measurement method is also proposed and applied to validate the numerical results of the damping coefficients experimentally. Given that the frequency response of the electric bearing is critically dependent on the damping coefficients at atmospheric pressure, a solution to the air-film damping measurement problem is presented by taking approximate curve fitting of multi-axis experimental frequency responses. The measured squeeze-film damping coefficients for the five-axis electric bearing agrees well with the numerical solutions. This indicates that numerical multiphysics simulation is an effective method to accurately examine the air-film damping effect for complex device geometry and arbitrary boundary condition. The accurate damping coefficients obtained by FEM simulation will greatly simplify the design of the five-axis bearing control system and facilitate the initial suspension test of the rotor for various micromotor devices.

Non-Linear Slosh Damping Model Development and Validation

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2015-01-01

Propellant tank slosh dynamics are typically represented by a mechanical model of spring mass damper. This mechanical model is then included in the equation of motion of the entire vehicle for Guidance, Navigation and Control (GN&C) analysis. For a partially-filled smooth wall propellant tank, the critical damping based on classical empirical correlation is as low as 0.05%. Due to this low value of damping, propellant slosh is potential sources of disturbance critical to the stability of launch and space vehicles. It is postulated that the commonly quoted slosh damping is valid only under the linear regime where the slosh amplitude is small. With the increase of slosh amplitude, the critical damping value should also increase. If this nonlinearity can be verified and validated, the slosh stability margin can be significantly improved, and the level of conservatism maintained in the GN&C analysis can be lessened. The purpose of this study is to explore and to quantify the dependence of slosh damping with slosh amplitude. Accurately predicting the extremely low damping value of a smooth wall tank is very challenging for any Computational Fluid Dynamics (CFD) tool. One must resolve thin boundary layers near the wall and limit numerical damping to minimum. This computational study demonstrates that with proper grid resolution, CFD can indeed accurately predict the low damping physics from smooth walls under the linear regime. Comparisons of extracted damping values with experimental data for different tank sizes show very good agreements. Numerical simulations confirm that slosh damping is indeed a function of slosh amplitude. When slosh amplitude is low, the damping ratio is essentially constant, which is consistent with the empirical correlation. Once the amplitude reaches a critical value, the damping ratio becomes a linearly increasing function of the slosh amplitude. A follow-on experiment validated the developed nonlinear damping relationship. This discovery can lead to significant savings by reducing the number and size of slosh baffles in liquid propellant tanks.

Demonstration of a switchable damping system to allow low-noise operation of high-Q low-mass suspension systems

NASA Astrophysics Data System (ADS)

Hennig, Jan-Simon; Barr, Bryan W.; Bell, Angus S.; Cunningham, William; Danilishin, Stefan L.; Dupej, Peter; Gräf, Christian; Hough, James; Huttner, Sabina H.; Jones, Russell; Leavey, Sean S.; Pascucci, Daniela; Sinclair, Martin; Sorazu, Borja; Spencer, Andrew; Steinlechner, Sebastian; Strain, Kenneth A.; Wright, Jennifer; Zhang, Teng; Hild, Stefan

2017-12-01

Low-mass suspension systems with high-Q pendulum stages are used to enable quantum radiation pressure noise limited experiments. Utilizing multiple pendulum stages with vertical blade springs and materials with high-quality factors provides attenuation of seismic and thermal noise; however, damping of these high-Q pendulum systems in multiple degrees of freedom is essential for practical implementation. Viscous damping such as eddy-current damping can be employed, but it introduces displacement noise from force noise due to thermal fluctuations in the damping system. In this paper we demonstrate a passive damping system with adjustable damping strength as a solution for this problem that can be used for low-mass suspension systems without adding additional displacement noise in science mode. We show a reduction of the damping factor by a factor of 8 on a test suspension and provide a general optimization for this system.

METEOSAT studies of clouds and radiation budget

NASA Technical Reports Server (NTRS)

Saunders, R. W.

1982-01-01

Radiation budget studies of the atmosphere/surface system from Meteosat, cloud parameter determination from space, and sea surface temperature measurements from TIROS N data are all described. This work was carried out on the interactive planetary image processing system (IPIPS), which allows interactive manipulationion of the image data in addition to the conventional computational tasks. The current hardware configuration of IPIPS is shown. The I(2)S is the principal interactive display allowing interaction via a trackball, four buttons under program control, or a touch tablet. Simple image processing operations such as contrast enhancing, pseudocoloring, histogram equalization, and multispectral combinations, can all be executed at the push of a button.

20 mm lithium button battery causing an oesophageal perforation in a toddler: lessons in diagnosis and treatment.

PubMed

Soccorso, Giampiero; Grossman, Ole; Martinelli, Massimo; Marven, Sean S; Patel, Kirtik; Thomson, Mike; Roberts, Julian P

2012-08-01

Swallowed button batteries (BB) which remain lodged in the oesophagus are at risk of serious complications, particularly in young children. The authors report a 3-year-old child, who rapidly developed an oesophageal perforation, following the ingestion of a 20-mm lithium BB which was initially mistaken for a coin. A thoracotomy and T-tube management of the perforation led to a positive outcome. BBs (20 mm) in children should be removed quickly and close observation is required as the damage initiated by the battery can lead to a significant injury within a few hours.

Hiroshima neutron fluence on a glass button from near ground zero.

PubMed

Fleischer, R L; Fujita, S; Hoshi, M

2001-12-01

A decorative glass button that was uncovered at a location that is 190 +/- 15 m from directly beneath the atomic explosion at Hiroshima on 6 August 1945 has been scanned for induced fission tracks produced mostly by the thermal neutrons from the bomb due to interactions with the trace uranium that is normally present in silicate glasses. In surveying 4.14 cm2 at 500x magnification, 28 tracks were seen. From a calibration irradiation in a nuclear reactor we infer that the neutron fluence in 1945 was 5.7(+/-1.1) x 10(11) cm(-2); and, allowing for shielding by the structure in which the button was probably located, the free-air (i.e., outside) value is estimated as 1.5(+/-0.5) x 10(12) cm(-2). A limit has been placed on possible fading of the radiation-damage tracks that could increase the fluence by at most a factor of 1.27. The values bracket the calculated value of 9 x 10(11) given in DS86 but are higher than the 3.6 x 10(11) inferred from induced radionuclides for the distance given. The difference is, however, within the observed variability of the two types of results.

Toward virtual anatomy: a stereoscopic 3-D interactive multimedia computer program for cranial osteology.

PubMed

Trelease, R B

1996-01-01

Advances in computer visualization and user interface technologies have enabled development of "virtual reality" programs that allow users to perceive and to interact with objects in artificial three-dimensional environments. Such technologies were used to create an image database and program for studying the human skull, a specimen that has become increasingly expensive and scarce. Stereoscopic image pairs of a museum-quality skull were digitized from multiple views. For each view, the stereo pairs were interlaced into a single, field-sequential stereoscopic picture using an image processing program. The resulting interlaced image files are organized in an interactive multimedia program. At run-time, gray-scale 3-D images are displayed on a large-screen computer monitor and observed through liquid-crystal shutter goggles. Users can then control the program and change views with a mouse and cursor to point-and-click on screen-level control words ("buttons"). For each view of the skull, an ID control button can be used to overlay pointers and captions for important structures. Pointing and clicking on "hidden buttons" overlying certain structures triggers digitized audio spoken word descriptions or mini lectures.

Influence of productivity and processing method on physicochemical characteristics of white button mushrooms in Brazil.

PubMed

Zied, Diego Cunha; Penachio, Sara Maciel; Dias, Eustáquio Souza; de Almeida Minhoni, Marli Teixeira; Ferraz, Rafael Augusto; Vieites, Rogério Lopes

2014-11-01

The white button mushroom is the edible fungus most commonly cultivated and commercialized in Brazil and worldwide. This work assesses the productivity of the different strains ABI 07/06 and ABI 06/05 of Agaricus bisporus grown under the conditions normally employed by growers in the southeast of Brazil, and the influence of four different chemical conservation methods on the physicochemical characteristics and storage properties of the fruit bodies. The productivities of strains ABI 07/06 and ABI 06/05 of white button mushrooms were found to be comparable. The colorimetric characteristics and chemical compositions (fat, fiber and protein contents) of the mushroom strains were similar, and these parameters were not influenced significantly by the conservation processes. Texture was negatively affected by all processing methods employed. It was concluded that chemical methods of processing mushrooms were not fully effective and novel alternative technologies should be considered by mushroom processors in Brazil. Some methods of mushroom storage using chemicals such as sodium metabisulfite are harmful to the human organism, so processing using autoclaving may be the best form of conservation of canned mushrooms. © 2014 Society of Chemical Industry.

Dual-Band Dual-Mode Button Antenna for On-Body and Off-Body Communications.

PubMed

Zhang, Xiu Yin; Wong, Hang; Mo, Te; Cao, Yun Fei

2017-08-01

A dual-band dual-mode button antenna for body centric communications is presented. At the lower band, a spiral inverted-F antenna is designed with omnidirectional radiation pattern for on-body communication. At the upper band, the high-order mode of the inverted-F antenna is utilized together with a metal reflector to realize broadside radiation for off-body communication. For demonstration, a prototype is implemented. The measured peak gains on the phantom at the lower and upper bands are -0.6 and 4.3 dBi, respectively. The antenna operating on the phantom has measured efficiencies of 46.3% at the lower band and 69.3% at the upper band. The issue of specific absorption rate (SAR) is studied. The maximum transmitted power under the SAR regulation of 1.6 W/kg is found to be 26.4 dB·m, which is high enough for body centric communications. In addition, the transmission performance between two proposed antennas mounted on the body is investigated by measuring the transmission loss. With an overall miniaturized size, the robust button antenna could be integrated in clothes and be a potential candidate for wireless body area network applications.

World Wide Web Metaphors for Search Mission Data

NASA Technical Reports Server (NTRS)

Norris, Jeffrey S.; Wallick, Michael N.; Joswig, Joseph C.; Powell, Mark W.; Torres, Recaredo J.; Mittman, David S.; Abramyan, Lucy; Crockett, Thomas M.; Shams, Khawaja S.; Fox, Jason M.;

Haptic Stylus and Empirical Studies on Braille, Button, and Texture Display

PubMed Central

Kyung, Ki-Uk; Lee, Jun-Young; Park, Junseok

2008-01-01

This paper presents a haptic stylus interface with a built-in compact tactile display module and an impact module as well as empirical studies on Braille, button, and texture display. We describe preliminary evaluations verifying the tactile display's performance indicating that it can satisfactorily represent Braille numbers for both the normal and the blind. In order to prove haptic feedback capability of the stylus, an experiment providing impact feedback mimicking the click of a button has been conducted. Since the developed device is small enough to be attached to a force feedback device, its applicability to combined force and tactile feedback display in a pen-held haptic device is also investigated. The handle of pen-held haptic interface was replaced by the pen-like interface to add tactile feedback capability to the device. Since the system provides combination of force, tactile and impact feedback, three haptic representation methods for texture display have been compared on surface with 3 texture groups which differ in direction, groove width, and shape. In addition, we evaluate its capacity to support touch screen operations by providing tactile sensations when a user rubs against an image displayed on a monitor. PMID:18317520

Haptic stylus and empirical studies on braille, button, and texture display.

PubMed

Kyung, Ki-Uk; Lee, Jun-Young; Park, Junseok

2008-01-01

This paper presents a haptic stylus interface with a built-in compact tactile display module and an impact module as well as empirical studies on Braille, button, and texture display. We describe preliminary evaluations verifying the tactile display's performance indicating that it can satisfactorily represent Braille numbers for both the normal and the blind. In order to prove haptic feedback capability of the stylus, an experiment providing impact feedback mimicking the click of a button has been conducted. Since the developed device is small enough to be attached to a force feedback device, its applicability to combined force and tactile feedback display in a pen-held haptic device is also investigated. The handle of pen-held haptic interface was replaced by the pen-like interface to add tactile feedback capability to the device. Since the system provides combination of force, tactile and impact feedback, three haptic representation methods for texture display have been compared on surface with 3 texture groups which differ in direction, groove width, and shape. In addition, we evaluate its capacity to support touch screen operations by providing tactile sensations when a user rubs against an image displayed on a monitor.

Voluntary and Involuntary Movements Widen the Window of Subjective Simultaneity.

PubMed

Arikan, B Ezgi; van Kemenade, Bianca M; Straube, Benjamin; Harris, Laurence R; Kircher, Tilo

2017-01-01

Forming a coherent percept of an event requires different sensory inputs originating from the event to be bound. Perceiving synchrony aids in binding of these inputs. In two experiments, we investigated how voluntary movements influence the perception of simultaneity, by measuring simultaneity judgments (SJs) for an audiovisual (AV) stimulus pair triggered by a voluntary button press. In Experiment 1, we manipulated contiguity between the action and its consequences by introducing delays between the button press and the AV stimulus pair. We found a widened window of subjective simultaneity (WSS) when the action-feedback relationship was time contiguous. Introducing a delay narrowed the WSS, suggesting that the wider WSS around the time of an action might facilitate perception of simultaneity. In Experiment 2, we introduced an involuntary condition using an externally controlled button to assess the influence of action-related predictive processes on SJs. We found a widened WSS around the action time, regardless of movement type, supporting the influence of causal relations in the perception of synchrony. Interestingly, the slopes of the psychometric functions in the voluntary condition were significantly steeper than the slopes in the involuntary condition, suggesting a role of action-related predictive mechanisms in making SJs more precise.

Voluntary and Involuntary Movements Widen the Window of Subjective Simultaneity

PubMed Central

Arikan, B. Ezgi; van Kemenade, Bianca M.; Straube, Benjamin; Harris, Laurence R.; Kircher, Tilo

2017-01-01

Forming a coherent percept of an event requires different sensory inputs originating from the event to be bound. Perceiving synchrony aids in binding of these inputs. In two experiments, we investigated how voluntary movements influence the perception of simultaneity, by measuring simultaneity judgments (SJs) for an audiovisual (AV) stimulus pair triggered by a voluntary button press. In Experiment 1, we manipulated contiguity between the action and its consequences by introducing delays between the button press and the AV stimulus pair. We found a widened window of subjective simultaneity (WSS) when the action-feedback relationship was time contiguous. Introducing a delay narrowed the WSS, suggesting that the wider WSS around the time of an action might facilitate perception of simultaneity. In Experiment 2, we introduced an involuntary condition using an externally controlled button to assess the influence of action-related predictive processes on SJs. We found a widened WSS around the action time, regardless of movement type, supporting the influence of causal relations in the perception of synchrony. Interestingly, the slopes of the psychometric functions in the voluntary condition were significantly steeper than the slopes in the involuntary condition, suggesting a role of action-related predictive mechanisms in making SJs more precise. PMID:28835813

Accuracy assessment of land surface temperature retrievals from Landsat 7 ETM + in the Dry Valleys of Antarctica using iButton temperature loggers and weather station data.

PubMed

Brabyn, Lars; Zawar-Reza, Peyman; Stichbury, Glen; Cary, Craig; Storey, Bryan; Laughlin, Daniel C; Katurji, Marwan

2014-04-01

The McMurdo Dry Valleys of Antarctica are the largest snow/ice-free regions on this vast continent, comprising 1% of the land mass. Due to harsh environmental conditions, the valleys are bereft of any vegetation. Land surface temperature is a key determinate of microclimate and a driver for sensible and latent heat fluxes of the surface. The Dry Valleys have been the focus of ecological studies as they arguably provide the simplest trophic structure suitable for modelling. In this paper, we employ a validation method for land surface temperatures obtained from Landsat 7 ETM + imagery and compared with in situ land surface temperature data collected from four transects totalling 45 iButtons. A single meteorological station was used to obtain a better understanding of daily and seasonal cycles in land surface temperatures. Results show a good agreement between the iButton and the Landsat 7 ETM + product for clear sky cases. We conclude that Landsat 7 ETM + derived land surface temperatures can be used at broad spatial scales for ecological and meteorological research.

Damage/Danger Associated Molecular Patterns (DAMPs) Modulate Chlamydia pecorum and C. trachomatis Serovar E Inclusion Development In Vitro.

PubMed

Leonard, Cory Ann; Schoborg, Robert V; Borel, Nicole

2015-01-01

Persistence, more recently termed the chlamydial stress response, is a viable but non-infectious state constituting a divergence from the characteristic chlamydial biphasic developmental cycle. Damage/danger associated molecular patterns (DAMPs) are normal intracellular components or metabolites that, when released from cells, signal cellular damage/lysis. Purine metabolite DAMPs, including extracellular ATP and adenosine, inhibit chlamydial development in a species-specific manner. Viral co-infection has been shown to reversibly abrogate Chlamydia inclusion development, suggesting persistence/chlamydial stress. Because viral infection can cause host cell DAMP release, we hypothesized DAMPs may influence chlamydial development. Therefore, we examined the effect of extracellular ATP, adenosine, and cyclic AMP exposure, at 0 and 14 hours post infection, on C. pecorum and C. trachomatis serovar E development. In the absence of de novo host protein synthesis, exposure to DAMPs immediately post or at 14 hours post infection reduced inclusion size; however, the effect was less robust upon 14 hours post infection exposure. Additionally, upon exposure to DAMPs immediately post infection, bacteria per inclusion and subsequent infectivity were reduced in both Chlamydia species. These effects were reversible, and C. pecorum exhibited more pronounced recovery from DAMP exposure. Aberrant bodies, typical in virus-induced chlamydial persistence, were absent upon DAMP exposure. In the presence of de novo host protein synthesis, exposure to DAMPs immediately post infection reduced inclusion size, but only variably modulated chlamydial infectivity. Because chlamydial infection and other infections may increase local DAMP concentrations, DAMPs may influence Chlamydia infection in vivo, particularly in the context of poly-microbial infections.

Elastic Moduli and Damping of Vibrational Modes of Aluminum/Silicon Carbide Composite Beams

NASA Technical Reports Server (NTRS)

Leidecker, Henning

1996-01-01

Elastic and shear moduli were determined for two aluminum matrix composites containing 20 and 40 volume percent discontinuous silicon carbide, respectively, using transverse, longitudinal, and torsional vibrational modes of specimens prepared as thin beams. These moduli are consistent with those determined from stress-strain measurements. The damping factors for these modes were also determined. Thermal properties are used to show that part of the damping of transverse modes is caused by the transverse thermal currents discussed by C. Zener (thermo-elastic damping); this damping is frequency-dependent with a maximum damping factor of approximately 0.002. The remaining damping is frequency-independent, and has roughly similar values in transverse, longitudinal, and torsional modes: approximately 0.0001.

Factors Controlling Superelastic Damping Capacity of SMAs

NASA Astrophysics Data System (ADS)

Heller, L.; Šittner, P.; Pilch, J.; Landa, M.

2009-08-01

In this paper, questions linked to the practical use of superelastic damping exploiting stress-induced martensitic transformation for vibration damping are addressed. Four parameters, particularly vibration amplitude, prestrain, temperature of surroundings, and frequency, are identified as having the most pronounced influence on the superelastic damping. Their influence on superelastic damping of a commercially available superelastic NiTi wire was experimentally investigated using a self-developed dedicated vibrational equipment. Experimental results show how the vibration amplitude, frequency, prestrain, and temperature affect the capacity of a superelastic NiTi wire to dissipate energy of vibrations through the superelastic damping. A special attention is paid to the frequency dependence (i.e., rate dependence) of the superelastic damping. It is shown that this is nearly negligible in case the wire is in the thermal chamber controlling actively the environmental temperature. In case of wire exposed to free environmental temperature in actual damping applications, however, the superelastic damping capacity significantly decreases with increasing frequency. This was explained to be a combined effect of the heat effects affecting the mean wire temperature and material properties with the help of simulations using the heat equation coupled phenomenological SMA model.

Passive damping in EDS maglev systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rote, D. M.

2002-05-03

There continues to be strong interest in the subjects of damping and drag forces associated with electrodynamic suspension (EDS) systems. While electromagnetic drag forces resist the forward motion of a vehicle and therefore consume energy, damping forces control, at least in part, the response of the vehicle to disturbances. Ideally, one would like to reduce the drag forces as much as possible while retaining adequate damping forces to insure dynamic stability and satisfactory ride quality. These two goals turn out to be difficult to achieve in practice. It is well known that maglev systems tend to be intrinsically under damped.more » Consequently it is often necessary in a practical system design to enhance the damping passively or actively. For reasons of cost and simplicity, it is desirable to rely as much as possible on passive damping mechanisms. In this paper, rough estimates are made of the passive damping and drag forces caused by various mechanisms in EDS systems. No attention will be given to active control systems or secondary suspension systems which are obvious ways to augment passive damping mechanisms if the latter prove to be inadequate.« less

Numerical Study of Particle Damping Mechanism in Piston Vibration System via Particle Dynamics Simulation

NASA Astrophysics Data System (ADS)

Bai, Xian-Ming; Shah, Binoy; Keer, Leon; Wang, Jane; Snurr, Randall

2008-03-01

Mechanical damping systems with granular particles as the damping media have promising applications in extreme temperature conditions. In particle-based damping systems, the mechanical energy is dissipated through the inelastic collision and friction of particles. In the past, many experiments have been performed to investigate the particle damping problems. However, the detailed energy dissipation mechanism is still unclear due to the complex collision and flow behavior of dense particles. In this work, we use 3-D particle dynamics simulation to investigate the damping mechanism of an oscillating cylinder piston immerged in millimeter-size steel particles. The time evolution of the energy dissipation through the friction and inelastic collision is accurately monitored during the damping process. The contribution from the particle-particle interaction and particle-wall interaction is also separated for investigation. The effects of moisture, surface roughness, and density of particles are carefully investigated in the simulation. The comparison between the numerical simulation and experiment is also performed. The simulation results can help us understand the particle damping mechanism and design the new generation of particle damping devices.

Flux-driven algebraic damping of m = 1 diocotron mode

NASA Astrophysics Data System (ADS)

Chim, Chi Yung; O'Neil, Thomas M.

2016-07-01

Recent experiments with pure electron plasmas in a Malmberg-Penning trap have observed the algebraic damping of m = 1 diocotron modes. Transport due to small field asymmetries produces a low density halo of electrons moving radially outward from the plasma core, and the mode damping begins when the halo reaches the resonant radius r = Rw at the wall of the trap. The damping rate is proportional to the flux of halo particles through the resonant layer. The damping is related to, but distinct from, spatial Landau damping, in which a linear wave-particle resonance produces exponential damping. This paper explains with analytic theory the new algebraic damping due to particle transport by both mobility and diffusion. As electrons are swept around the "cat's eye" orbits of the resonant wave-particle interaction, they form a dipole (m = 1) density distribution. From this distribution, the electric field component perpendicular to the core displacement produces E × B-drift of the core back to the axis, that is, damps the m = 1 mode. The parallel component produces drift in the azimuthal direction, that is, causes a shift in the mode frequency.

Effects of temperature and pressure on the performance of a solid oxide fuel cell running on steam reformate of kerosene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chick, Lawrence A.; Marina, Olga A.; Coyle, Christopher A.

2013-08-15

A button solid oxide fuel cell with a La0.6Sr0.4Co0.2Fe0.8O3 cathode and a nickel-YSZ anode was tested over a range of temperatures from 650 to 800°C and a range of pressures from 101 to 724 kPa. The fuel was simulated steam-reformed kerosene and the oxidant was air. The observed increases in open circuit voltages (OCV) were accurately predicted by the Nernst equation. Kinetics also increased, although the power boost due to kinetics was about two thirds as large as the boost due to OCV. The total power boost in going from 101 to 724 kPa at 750°C and 0.8 volts wasmore » 66%. Impedance spectroscopy demonstrated a significant decrease in electrodic losses at elevated pressures. Complex impedance spectra were dominated by a combination of low frequency processes that decreased markedly with increasing pressure. A composite of high-frequency processes also decreased with pressure, but to a lesser extent. An empirical algorithm that accurately predicts the increased fuel cell performance at elevated pressures was developed for our results and was also suitable for some, but not all, data reported in the literature.« less

Multi-threshold de-noising of electrical imaging logging data based on the wavelet packet transform

NASA Astrophysics Data System (ADS)

Xie, Fang; Xiao, Chengwen; Liu, Ruilin; Zhang, Lili

2017-08-01

A key problem of effectiveness evaluation for fractured-vuggy carbonatite reservoir is how to accurately extract fracture and vug information from electrical imaging logging data. Drill bits quaked during drilling and resulted in rugged surfaces of borehole walls and thus conductivity fluctuations in electrical imaging logging data. The occurrence of the conductivity fluctuations (formation background noise) directly affects the fracture/vug information extraction and reservoir effectiveness evaluation. We present a multi-threshold de-noising method based on wavelet packet transform to eliminate the influence of rugged borehole walls. The noise is present as fluctuations in button-electrode conductivity curves and as pockmarked responses in electrical imaging logging static images. The noise has responses in various scales and frequency ranges and has low conductivity compared with fractures or vugs. Our de-noising method is to decompose the data into coefficients with wavelet packet transform on a quadratic spline basis, then shrink high-frequency wavelet packet coefficients in different resolutions with minimax threshold and hard-threshold function, and finally reconstruct the thresholded coefficients. We use electrical imaging logging data collected from fractured-vuggy Ordovician carbonatite reservoir in Tarim Basin to verify the validity of the multi-threshold de-noising method. Segmentation results and extracted parameters are shown as well to prove the effectiveness of the de-noising procedure.

Random vibrations of quadratic damping systems. [optimum damping analysis for automobile suspension system

NASA Technical Reports Server (NTRS)

Sireteanu, T.

1974-01-01

An oscillating system with quadratic damping subjected to white noise excitation is replaced by a nonlinear, statistically equivalent system for which the associated Fokker-Planck equation can be exactly solved. The mean square responses are calculated and the optimum damping coefficient is determined with respect to the minimum mean square acceleration criteria. An application of these results to the optimization of automobile suspension damping is given.

Hybrid passive/active damping for robust multivariable acoustic control in composite plates

NASA Astrophysics Data System (ADS)

Veeramani, Sudha; Wereley, Norman M.

1996-05-01

Noise transmission through a flexible kevlar-epoxy composite trim panel into an acoustic cavity or box is studied with the intent of controlling the interior sound fields. A hybrid noise attenuation technique is proposed which uses viscoelastic damping layers in the composite plate for passive attenuation of high frequency noise transmission, and uses piezo-electric patch actuators for active control in the low frequency range. An adaptive feedforward noise control strategy is applied. The passive structural damping augmentation incorporated in the composite plates is also intended to increase stability robustness of the active noise control strategy. A condenser microphone in the interior of the enclosure functions as the error sensor. Three composite plates were experimentally evaluated: one with no damping layer, the second with a 10 mil damping layer, and the third with a 15 mil damping layer. The damping layer was cocured in the kevlar-epoxy trim panels. Damping in the plates was increased from 1.6% for the plate with no damping layer, to 5.9% for the plate with a 15 mil damping layer. In experimental studies, the improved stability robustness of the controller was demonstrated by improved adaptive feedforward control algorithm convergence. A preliminary analytical model is presented that describes the dynamic behavior of a composite panel actuated by piezoelectric actuators bonded to its surface.

The Serum Analysis of Dampness Syndrome in Patients with Coronary Heart Disease and Chronic Renal Failure Based on the Theory of "Same Syndromes in Different Diseases".

PubMed

Hao, Yiming; Yuan, Xue; Qian, Peng; Bai, Guanfeng; Wang, Yiqin

2017-01-01

To analyze the serum metabolites in patients with coronary heart disease (CHD) showing dampness syndrome and patients with chronic renal failure (CRF) showing dampness syndrome and to seek the substance that serves as the underlying basis of dampness syndrome in "same syndromes in different diseases." Methods . Metabolic spectrum by GC-MS was performed using serum samples from 29 patients with CHD showing dampness syndrome and 32 patients with CRF showing dampness syndrome. The principal component analysis and statistical analysis of partial least squares were performed to detect the metabolites with different levels of expression in patients with CHD and CRF. Furthermore, by comparing the VIP value and data mining in METLIN and HMDB, we identified the common metabolites in both patient groups. (1) Ten differential metabolites were found in patients with CHD showing dampness syndrome when compared to healthy subjects. Meanwhile, nine differential metabolites were found in patients with CRF showing dampness syndrome when compared to healthy subjects. (2) There were 9 differential metabolites identified when the serum metabolites of the CHD patients with dampness syndrome were compared to those of CRF patients with dampness syndrome. There were 4 common metabolites found in the serums of both patient groups.

Cu-Al-Ni-SMA-Based High-Damping Composites

NASA Astrophysics Data System (ADS)

López, Gabriel A.; Barrado, Mariano; San Juan, Jose; Nó, María Luisa

2009-08-01

Recently, absorption of vibration energy by mechanical damping has attracted much attention in several fields such as vibration reduction in aircraft and automotive industries, nanoscale vibration isolations in high-precision electronics, building protection in civil engineering, etc. Typically, the most used high-damping materials are based on polymers due to their viscoelastic behavior. However, polymeric materials usually show a low elastic modulus and are not stable at relatively low temperatures (≈323 K). Therefore, alternative materials for damping applications are needed. In particular, shape memory alloys (SMAs), which intrinsically present high-damping capacity thanks to the dissipative hysteretic movement of interfaces under external stresses, are very good candidates for high-damping applications. A completely new approach was applied to produce high-damping composites with relatively high stiffness. Cu-Al-Ni shape memory alloy powders were embedded with metallic matrices of pure In, a In-10wt.%Sn alloy and In-Sn eutectic alloy. The production methodology is described. The composite microstructures and damping properties were characterized. A good particle distribution of the Cu-Al-Ni particles in the matrices was observed. The composites exhibit very high damping capacities in relatively wide temperature ranges. The methodology introduced provides versatility to control the temperature of maximum damping by adjusting the shape memory alloy composition.

Real time simulation application to monitor the stability limit of power system

NASA Astrophysics Data System (ADS)

Hartono, Kuo, Ming-Tse

2017-06-01

If the power system falls into an unsteady state, there will be voltage collapse in which the power system will be separated into small systems. Identifying the stability reserve in conformity with a certain practical operation condition is very important for the system management and operation. In fact, the global power system issue has caused serious outages due to voltage collapse such as in the United States-Canada in August 14, 2003; South London in August 28, 2003; southern Sweden and eastern Denmark in September 23, 2003; and Italy on September 28, 2003, and in Vietnam where power system problem led to power loss on 17 May 2005, 27 December 2006, 20 July 2007, and 10 September 2007. The analysis shows that the phenomenon is related to the loss of system stability. Thus, the operational system as well as the power system designs should be studied related to the issue of the system stability. To study the static stability of the power system, different approximate standards, called pragmatic criteria, were examined. Markovits has investigated the application of the standard of dP/dd to test the stability of the power button and dq/dU to check the voltage stability of the load button [1]. However, the storage stability when calculating standard dP/d d is usually much larger than the reserves when calculating standard dq/dU [1]. This paper presents a method to build a possible operation region in the power plane of load bus which works in comply with the stability limit to evaluate the stability reserve of the power system. This method is used to build a program to monitor the stability reserve of IEEE 39 Bus Power System in real time. To monitor the stability reserve of IEEE 39 nodes power system, articles based on the standard dq/dU was used to calculate the assessment. When using standard dq/dU to check for voltage stability load button, the amount of storage stability can be calculated by the following steps: first, transformed replacement scheme Masonry on the schematic rays of the source and node load stability was examined by using Gaussian elimination algorithm [1, 2, 3], then on the basis of ray diagrams the construction work, allowed domain of spare capacity load capacity in space and storage stability for the load button were determined. The GS-ODT program was built on the basis of Gaussian elimination algorithm and stable domain construction work algorithm for Masonic load button by dQ/dU pragmatic criteria. The GS-ODT program has a simple interface and easy to use with the main function is to identify the allowed domain for the load button and thus can assess visually stable reserve still according to the load capacity of the nodes of the IEEE 39 nodes power system in real-time.

Constraint damping for the Z4c formulation of general relativity

NASA Astrophysics Data System (ADS)

Weyhausen, Andreas; Bernuzzi, Sebastiano; Hilditch, David

2012-01-01

One possibility for avoiding constraint violation in numerical relativity simulations adopting free-evolution schemes is to modify the continuum evolution equations so that constraint violations are damped away. Gundlach et al. demonstrated that such a scheme damps low-amplitude, high-frequency constraint-violating modes exponentially for the Z4 formulation of general relativity. Here we analyze the effect of the damping scheme in numerical applications on a conformal decomposition of Z4. After reproducing the theoretically predicted damping rates of constraint violations in the linear regime, we explore numerical solutions not covered by the theoretical analysis. In particular we examine the effect of the damping scheme on low-frequency and on high-amplitude perturbations of flat spacetime as well and on the long-term dynamics of puncture and compact star initial data in the context of spherical symmetry. We find that the damping scheme is effective provided that the constraint violation is resolved on the numerical grid. On grid noise the combination of artificial dissipation and damping helps to suppress constraint violations. We find that care must be taken in choosing the damping parameter in simulations of puncture black holes. Otherwise the damping scheme can cause undesirable growth of the constraints, and even qualitatively incorrect evolutions. In the numerical evolution of a compact static star we find that the choice of the damping parameter is even more delicate, but may lead to a small decrease of constraint violation. For a large range of values it results in unphysical behavior.

Dynamic Modulus and Damping of Boron, Silicon Carbide, and Alumina Fibers

NASA Technical Reports Server (NTRS)

Dicarlo, J. A.; Williams, W.

1980-01-01

The dynamic modulus and damping capacity for boron, silicon carbide, and silicon carbide coated boron fibers were measured from-190 to 800 C. The single fiber vibration test also allowed measurement of transverse thermal conductivity for the silicon carbide fibers. Temperature dependent damping capacity data for alumina fibers were calculated from axial damping results for alumina-aluminum composites. The dynamics fiber data indicate essentially elastic behavior for both the silicon carbide and alumina fibers. In contrast, the boron based fibers are strongly anelastic, displaying frequency dependent moduli and very high microstructural damping. Ths single fiber damping results were compared with composite damping data in order to investigate the practical and basic effects of employing the four fiber types as reinforcement for aluminum and titanium matrices.

Bounce-harmonic Landau Damping of Plasma Waves

NASA Astrophysics Data System (ADS)

Anderegg, Francois

2015-11-01

We present measurement of plasma wave damping, spanning the temperature regimes of direct Landau damping, bounce-harmonic Landau damping, inter-species drag damping, and viscous damping. Direct Landau damping is dominant at high temperatures, but becomes negligible as v

Description of and preliminary tests results for the Joint Damping Experiment (JDX)

NASA Technical Reports Server (NTRS)

Bingham, Jeffrey G.; Folkman, Steven L.

1995-01-01

An effort is currently underway to develop an experiment titled joint Damping E_periment (JDX) to fly on the Space Shuttle as Get Away Special Payload G-726. This project is funded by NASA's IN-Space Technology Experiments Program and is scheduled to fly in July 1995 on STS-69. JDX will measure the influence of gravity on the structural damping of a three bay truss having clearance fit pinned joints. Structural damping is an important parameter in the dynamics of space structures. Future space structures will require more precise knowledge of structural damping than is currently available. The mission objectives are to develop a small-scale shuttle flight experiment that allows researchers to: (1) characterize the influence of gravity and joint gaps on structural damping and dynamic behavior of a small-scale truss model, and (2) evaluate the applicability of low-g aircraft test results for predicting on-orbit behavior. Completing the above objectives will allow a better understanding and/or prediction of structural damping occurring in a pin jointed truss. Predicting damping in joints is quite difficult. One of the important variables influencing joint damping is gravity. Previous work has shown that gravity loads can influence damping in a pin jointed truss structure. Flying this experiment as a GAS payload will allow testing in a microgravity environment. The on-orbit data (in micro-gravity) will be compared with ground test results. These data will be used to help develop improved models to predict damping due to pinned joints. Ground and low-g aircraft testing of this experiment has been completed. This paper describes the experiment and presents results of both ground and low-g aircraft tests which demonstrate that damping of the truss is dramatically influenced by gravity.

Design, analysis, and testing of high frequency passively damped struts

NASA Technical Reports Server (NTRS)

Yiu, Y. C.; Davis, L. Porter; Napolitano, Kevin; Ninneman, R. Rory

1993-01-01

Objectives of the research are: (1) to develop design requirements for damped struts to stabilize control system in the high frequency cross-over and spill-over range; (2) to design, fabricate and test viscously damped strut and viscoelastically damped strut; (3) to verify accuracy of design and analysis methodology of damped struts; and (4) to design and build test apparatus, and develop data reduction algorithm to measure strut complex stiffness. In order to meet the stringent performance requirements of the SPICE experiment, the active control system is used to suppress the dynamic responses of the low order structural modes. However, the control system also inadvertently drives some of the higher order modes unstable in the cross-over and spill-over frequency range. Passive damping is a reliable and effective way to provide damping to stabilize the control system. It also improves the robustness of the control system. Damping is designed into the SPICE testbed as an integral part of the control-structure technology.

Damping profile of standing kink oscillations observed by SDO/AIA

NASA Astrophysics Data System (ADS)

Pascoe, D. J.; Goddard, C. R.; Nisticò, G.; Anfinogentov, S.; Nakariakov, V. M.

2016-01-01

Aims: Strongly damped standing and propagating kink oscillations are observed in the solar corona. This can be understood in terms of mode coupling, which causes the wave energy to be converted from the bulk transverse oscillation to localised, unresolved azimuthal motions. The damping rate can provide information about the loop structure, and theory predicts two possible damping profiles. Methods: We used the recently compiled catalogue of decaying standing kink oscillations of coronal loops to search for examples with high spatial and temporal resolution and sufficient signal quality to allow the damping profile to be examined. The location of the loop axis was tracked, detrended, and fitted with sinusoidal oscillations with Gaussian and exponential damping profiles. Results: Using the highest quality data currently available, we find that for the majority of our cases a Gaussian profile describes the damping behaviour at least as well as an exponential profile, which is consistent with the recently developed theory for the damping profile due to mode coupling.

Flux-driven algebraic damping of diocotron modes

NASA Astrophysics Data System (ADS)

Chim, Chi Yung; O'Neil, Thomas M.

2015-06-01

Recent experiments with pure electron plasmas in a Malmberg-Penning trap have observed the algebraic damping of m = 1 and m = 2 diocotron modes. Transport due to small field asymmetries produces a low density halo of electrons moving radially outward from the plasma core, and the mode damping begins when the halo reaches the resonant radius Rm, where there is a matching of ωm = mωE (Rm) for the mode frequency ωm and E × B-drift rotation frequency ωE. The damping rate is proportional to the flux of halo particles through the resonant layer. The damping is related to, but distinct from, spatial Landau damping, in which a linear wave-particle resonance produces exponential damping. This new mechanism of damping is due to transfer of canonical angular momentum from the mode to halo particles, as they are swept around the "cat's eye" orbits of the resonant wave-particle interaction. This paper provides a simple derivation of the time dependence of the mode amplitudes.

Comparative study of popular objective functions for damping power system oscillations in multimachine system.

PubMed

Islam, Naz Niamul; Hannan, M A; Shareef, Hussain; Mohamed, Azah; Salam, M A

2014-01-01

Power oscillation damping controller is designed in linearized model with heuristic optimization techniques. Selection of the objective function is very crucial for damping controller design by optimization algorithms. In this research, comparative analysis has been carried out to evaluate the effectiveness of popular objective functions used in power system oscillation damping. Two-stage lead-lag damping controller by means of power system stabilizers is optimized using differential search algorithm for different objective functions. Linearized model simulations are performed to compare the dominant mode's performance and then the nonlinear model is continued to evaluate the damping performance over power system oscillations. All the simulations are conducted in two-area four-machine power system to bring a detailed analysis. Investigated results proved that multiobjective D-shaped function is an effective objective function in terms of moving unstable and lightly damped electromechanical modes into stable region. Thus, D-shape function ultimately improves overall system damping and concurrently enhances power system reliability.

Mechanics of damping for fiber composite laminates including hygro-thermal effects

NASA Technical Reports Server (NTRS)

Saravanos, D. A.; Chamis, C. C.

1989-01-01

An integrated mechanics theory has been developed for the modeling of composite damping from the micromechanics to the laminate level. Simplified, design oriented equations based on hysteretic damping are presented for on-axis plies, off-axis plies, and laminates including the effect of temperature, moisture, and interply hysteretic damping. The temperature rise within vibrating composite laminates resulting from strain energy dissipation is also modeled, and their coupled hygro-thermo-mechanical response is predicted. The method correlates well with reported damping measurements. Application examples illustrate the effect of various ply, laminate, and hygro-thermal parameters on the overall damping performance of composite laminates.

Mechanics of damping for fiber composite laminates including hygro-thermal effects

NASA Technical Reports Server (NTRS)

Saravanos, D. A.; Chamis, Christos C.

1989-01-01

An integrated mechanics theory was developed for the modeling of composite damping from the micromechanics to the laminate level. Simplified, design oriented equations based on hysteretic damping are presented for on-axis plies, off-axis plies, and laminates including the effect of temperature, moisture, and interply hysteretic damping. The temperature rise within vibrating composite laminates resulting from strain energy dissipation is also modeled, and their coupled hygro-thermo-mechanical response is predicted. The method correlates well with reported damping measurements. Application examples illustrate the effect of various ply, laminate, and hygro-thermal parameters on the overall damping performance of composite laminates.

Effects of damping on mode shapes, volume 1

NASA Technical Reports Server (NTRS)

Gates, R. M.

1977-01-01

Displacement, velocity, and acceleration admittances were calculated for a realistic NASTRAN structural model of space shuttle for three conditions: liftoff, maximum dynamic pressure and end of solid rocket booster burn. The realistic model of the orbiter, external tank, and solid rocket motors included the representation of structural joint transmissibilities by finite stiffness and damping elements. Methods developed to incorporate structural joints and their damping characteristics into a finite element model of the space shuttle, to determine the point damping parameters required to produce realistic damping in the primary modes, and to calculate the effect of distributed damping on structural resonances through the calculation of admittances.

Comparison of Damping Mechanisms for Transverse Waves in Solar Coronal Loops

NASA Astrophysics Data System (ADS)

Montes-Solís, María; Arregui, Iñigo

2017-09-01

We present a method to assess the plausibility of alternative mechanisms to explain the damping of magnetohydrodynamic transverse waves in solar coronal loops. The considered mechanisms are resonant absorption of kink waves in the Alfvén continuum, phase mixing of Alfvén waves, and wave leakage. Our methods make use of Bayesian inference and model comparison techniques. We first infer the values for the physical parameters that control the wave damping, under the assumption of a particular mechanism, for typically observed damping timescales. Then, the computation of marginal likelihoods and Bayes factors enable us to quantify the relative plausibility between the alternative mechanisms. We find that, in general, the evidence is not large enough to support a single particular damping mechanism as the most plausible one. Resonant absorption and wave leakage offer the most probable explanations in strong damping regimes, while phase mixing is the best candidate for weak/moderate damping. When applied to a selection of 89 observed transverse loop oscillations, with their corresponding measurements of damping timescales and taking into account data uncertainties, we find that positive evidence for a given damping mechanism is only available in a few cases.

Extension of Miles Equation for Ring Baffle Damping Predictions to Small Slosh Amplitudes and Large Baffle Widths

NASA Technical Reports Server (NTRS)

West, Jeff; Yang, H. Q.; Brodnick, Jacob; Sansone, Marco; Westra, Douglas

2016-01-01

The Miles equation has long been used to predict slosh damping in liquid propellant tanks due to ring baffles. The original work by Miles identifies defined limits to its range of application. Recent evaluations of the Space Launch System identified that the Core Stage baffle designs resulted in violating the limits of the application of the Miles equation. This paper describes the work conducted by NASA/MSFC to develop methods to predict slosh damping from ring baffles for conditions for which Miles equation is not applicable. For asymptotically small slosh amplitudes or conversely large baffle widths, an asymptotic expression for slosh damping was developed and calibrated using historical experimental sub-scale slosh damping data. For the parameter space that lies between region of applicability of the asymptotic expression and the Miles equation, Computational Fluid Dynamics simulations of slosh damping were used to develop an expression for slosh damping. The combined multi-regime slosh prediction methodology is shown to be smooth at regime boundaries and consistent with both sub-scale experimental slosh damping data and the results of validated Computational Fluid Dynamics predictions of slosh damping due to ring baffles.

Dynamic characteristics of a novel damped outrigger system

NASA Astrophysics Data System (ADS)

Tan, Ping; Fang, Chuangjie; Zhou, Fulin

2014-06-01

This paper presents exact analytical solutions for a novel damped outrigger system, in which viscous dampers are vertically installed between perimeter columns and the core of a high-rise building. An improved analytical model is developed by modeling the effect of the damped outrigger as a general rotational spring acting on a Bernoulli-Euler beam. The equivalent rotational spring stiffness incorporating the combined effects of dampers and axial stiffness of perimeter columns is derived. The dynamic stiffness method (DSM) is applied to formulate the governing equation of the damped outrigger system. The accuracy and efficiency are verified in comparison with those obtained from compatibility equations and boundary equations. Parametric analysis of three non-dimensional factors is conducted to evaluate the influences of various factors, such as the stiffness ratio of the core to the beam, position of the damped outrigger, and the installed damping coefficient. Results show that the modal damping ratio is significantly influenced by the stiffness ratio of the core to the column, and is more sensitive to damping than the position of the damped outrigger. The proposed analytical model in combination with DSM can be extended to the study of structures with more outriggers.

Comparison of Damping Mechanisms for Transverse Waves in Solar Coronal Loops

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montes-Solís, María; Arregui, Iñigo, E-mail: mmsolis@iac.es

We present a method to assess the plausibility of alternative mechanisms to explain the damping of magnetohydrodynamic transverse waves in solar coronal loops. The considered mechanisms are resonant absorption of kink waves in the Alfvén continuum, phase mixing of Alfvén waves, and wave leakage. Our methods make use of Bayesian inference and model comparison techniques. We first infer the values for the physical parameters that control the wave damping, under the assumption of a particular mechanism, for typically observed damping timescales. Then, the computation of marginal likelihoods and Bayes factors enable us to quantify the relative plausibility between the alternativemore » mechanisms. We find that, in general, the evidence is not large enough to support a single particular damping mechanism as the most plausible one. Resonant absorption and wave leakage offer the most probable explanations in strong damping regimes, while phase mixing is the best candidate for weak/moderate damping. When applied to a selection of 89 observed transverse loop oscillations, with their corresponding measurements of damping timescales and taking into account data uncertainties, we find that positive evidence for a given damping mechanism is only available in a few cases.« less

Process Damping and Cutting Tool Geometry in Machining

NASA Astrophysics Data System (ADS)

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

2011-12-01

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

Model predictive control of an air suspension system with damping multi-mode switching damper based on hybrid model

NASA Astrophysics Data System (ADS)

Sun, Xiaoqiang; Yuan, Chaochun; Cai, Yingfeng; Wang, Shaohua; Chen, Long

2017-09-01

This paper presents the hybrid modeling and the model predictive control of an air suspension system with damping multi-mode switching damper. Unlike traditional damper with continuously adjustable damping, in this study, a new damper with four discrete damping modes is applied to vehicle semi-active air suspension. The new damper can achieve different damping modes by just controlling the on-off statuses of two solenoid valves, which makes its damping adjustment more efficient and more reliable. However, since the damping mode switching induces different modes of operation, the air suspension system with the new damper poses challenging hybrid control problem. To model both the continuous/discrete dynamics and the switching between different damping modes, the framework of mixed logical dynamical (MLD) systems is used to establish the system hybrid model. Based on the resulting hybrid dynamical model, the system control problem is recast as a model predictive control (MPC) problem, which allows us to optimize the switching sequences of the damping modes by taking into account the suspension performance requirements. Numerical simulations results demonstrate the efficacy of the proposed control method finally.

Closed-form eigensolutions of nonviscously, nonproportionally damped systems based on continuous damping sensitivity

NASA Astrophysics Data System (ADS)

Lázaro, Mario

2018-01-01

In this paper, nonviscous, nonproportional, vibrating structures are considered. Nonviscously damped systems are characterized by dissipative mechanisms which depend on the history of the response velocities via hereditary kernel functions. Solutions of the free motion equation lead to a nonlinear eigenvalue problem involving mass, stiffness and damping matrices. Viscoelasticity leads to a frequency dependence of this latter. In this work, a novel closed-form expression to estimate complex eigenvalues is derived. The key point is to consider the damping model as perturbed by a continuous fictitious parameter. Assuming then the eigensolutions as function of this parameter, the computation of the eigenvalues sensitivity leads to an ordinary differential equation, from whose solution arises the proposed analytical formula. The resulting expression explicitly depends on the viscoelasticity (frequency derivatives of the damping function), the nonproportionality (influence of the modal damping matrix off-diagonal terms). Eigenvectors are obtained using existing methods requiring only the corresponding eigenvalue. The method is validated using a numerical example which compares proposed with exact ones and with those determined from the linear first order approximation in terms of the damping matrix. Frequency response functions are also plotted showing that the proposed approach is valid even for moderately or highly damped systems.

Characteristics of a capillary-discharge flash x-ray generator

NASA Astrophysics Data System (ADS)

Sato, Eiichi; Hayasi, Yasuomi; Usuki, Tatsumi; Sato, Koetsu; Takayama, Kazuyoshi; Ido, Hideaki

2002-11-01

The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments are primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 0.2 μF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damp oscillations. The peak values of the voltage and current increased when the charging voltage was increased and their maximum values were -10.8 kV and 4.7 kV, respectively. The x-ray durations observed by a 1.6 μm aluminum filter were less than 30 μs, and we detected the aluminum characteristic x-ray intensity using a 6.8 μm aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in teh condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted greatly after pass through two slits.

Quadratic Damping

ERIC Educational Resources Information Center

Fay, Temple H.

2012-01-01

Quadratic friction involves a discontinuous damping term in equations of motion in order that the frictional force always opposes the direction of the motion. Perhaps for this reason this topic is usually omitted from beginning texts in differential equations and physics. However, quadratic damping is more realistic than viscous damping in many…

Magnetic Damping For Maglev

DOE PAGES

Zhu, S.; Cai, Y.; Rote, D. M.; ...

1998-01-01

Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.

Torsional and axial damping properties of the AZ31B-F magnesium alloy

NASA Astrophysics Data System (ADS)

Anes, V.; Lage, Y. E.; Vieira, M.; Maia, N. M. M.; Freitas, M.; Reis, L.

2016-10-01

Damping properties for the AZ31B-F magnesium alloy were evaluated for pure axial and pure shear loading conditions at room temperature. Hysteretic damping results were measured through stress-strain controlled tests. Moreover, the magnesium alloy viscous damping was measured with frequency response functions and free vibration decay, both results were obtained by experiments. The axial and shear damping ratio (ASDR) has been identified and described, specifically for free vibration conditions.

Self-Regulating Shock Absorber

NASA Technical Reports Server (NTRS)

Wesselski, Clarence J.

1995-01-01

Mechanical shock absorber keeps frictional damping force within tolerable limit. Its damping force does not increase with coefficient of friction between energy-absorbing components; rather, frictional damping force varies only slightly. Relatively insensitive to manufacturing variations and environmental conditions altering friction. Does not exhibit high breakaway friction and consequent sharp increase followed by sharp decrease in damping force at beginning of stroking. Damping force in absorber does not vary appreciably with speed of stroking. In addition, not vulnerable to leakage of hydraulic fluid.

A novel approach to the analysis of squeezed-film air damping in microelectromechanical systems

NASA Astrophysics Data System (ADS)

Yang, Weilin; Li, Hongxia; Chatterjee, Aveek N.; Elfadel, Ibrahim (Abe M.; Ender Ocak, Ilker; Zhang, TieJun

2017-01-01

Squeezed-film damping (SFD) is a phenomenon that significantly affects the performance of micro-electro-mechanical systems (MEMS). The total damping force in MEMS mainly include the viscous damping force and elastic damping force. Quality factor (Q factor) is usually used to evaluate the damping in MEMS. In this work, we measure the Q factor of a resonator through experiments in a wide range of pressure levels. In fact, experimental characterizations of MEMS have some limitations because it is difficult to conduct experiments at very high vacuum and also hard to differentiate the damping mechanisms from the overall Q factor measurements. On the other hand, classical theoretical analysis of SFD is restricted to strong assumptions and simple geometries. In this paper, a novel numerical approach, which is based on lattice Boltzmann simulations, is proposed to investigate SFD in MEMS. Our method considers the dynamics of squeezed air flow as well as fluid-solid interactions in MEMS. It is demonstrated that Q factor can be directly predicted by numerical simulation, and our simulation results agree well with experimental data. Factors that influence SFD, such as pressure, oscillating amplitude, and driving frequency, are investigated separately. Furthermore, viscous damping and elastic damping forces are quantitatively compared based on comprehensive simulation. The proposed numerical approach as well as experimental characterization enables us to reveal the insightful physics of squeezed-film air damping in MEMS.

The Serum Analysis of Dampness Syndrome in Patients with Coronary Heart Disease and Chronic Renal Failure Based on the Theory of “Same Syndromes in Different Diseases”

PubMed Central

Yuan, Xue; Bai, Guanfeng

2017-01-01

Aim To analyze the serum metabolites in patients with coronary heart disease (CHD) showing dampness syndrome and patients with chronic renal failure (CRF) showing dampness syndrome and to seek the substance that serves as the underlying basis of dampness syndrome in “same syndromes in different diseases.” Methods. Metabolic spectrum by GC-MS was performed using serum samples from 29 patients with CHD showing dampness syndrome and 32 patients with CRF showing dampness syndrome. The principal component analysis and statistical analysis of partial least squares were performed to detect the metabolites with different levels of expression in patients with CHD and CRF. Furthermore, by comparing the VIP value and data mining in METLIN and HMDB, we identified the common metabolites in both patient groups. Results (1) Ten differential metabolites were found in patients with CHD showing dampness syndrome when compared to healthy subjects. Meanwhile, nine differential metabolites were found in patients with CRF showing dampness syndrome when compared to healthy subjects. (2) There were 9 differential metabolites identified when the serum metabolites of the CHD patients with dampness syndrome were compared to those of CRF patients with dampness syndrome. There were 4 common metabolites found in the serums of both patient groups. PMID:28713825

Measurement of damping of graphite epoxy composite materials and structural joints

NASA Technical Reports Server (NTRS)

Crocker, Malcolm J.; Rao, Mohan D.; Raju, P. K.; Yan, Xinche

1989-01-01

The damping capacity of graphite epoxy materials and structural joints was evaluated. The damping ratio of different composite specimens and bonded joints were systematically evaluated under normal atmospheric conditions and in a vacuum environment. Free and forced vibration test methods were employed for measuring the damping ratios. The effect of edge support conditions on the damping value of a composite tube specimen was studied by using a series of experiments performed on the specimen with different edge supports. It was found that simulating a free-free boundary conditions by having no constraints at the ends gives the lowest value of the material damping of the composite. The accuracy of the estimation of the damping ratio value was improved by using a curve-fitting technique on the response data obtained through measurement. The effect of outgassing (moisture desorption) on the damping capacity was determined by measuring the damping ratio of the tube specimen in a vacuum environment before and after outgassing had occurred. The effects of high and low temperatures on the damping was also investigated by using a series of experiments on tube and beam specimens. An analytical model to study the vibrations of a bonded lap joint system was formulated. Numerical results were generated for different overlap ratios of the system. These were compared with experimental results. In order to determine the influence of bonded joints on the material damping capacity, experiments were conducted on bonded lap-jointed and double-butt-jointed specimens. These experimental results were compared with simple beam specimens with no joints.

The effects of preferred and non-preferred running strike patterns on tissue vibration properties.

PubMed

Enders, Hendrik; von Tscharner, Vinzenz; Nigg, Benno M

2014-03-01

To characterize soft tissue vibrations during running with a preferred and a non-preferred strike pattern in shoes and barefoot. Cross-sectional study. Participants ran at 3.5 m s(-1) on a treadmill in shoes and barefoot using a rearfoot and a forefoot strike for each footwear condition. The preferred strike patterns for the subjects were a rearfoot strike and a forefoot strike for shod and barefoot running, respectively. Vibrations were recorded with an accelerometer overlying the belly of the medial gastrocnemius. Thirteen non-linearly scaled wavelets were used for the analysis. Damping was calculated as the overall decay of power in the acceleration signal post ground contact. A higher damping coefficient indicates higher damping capacities of the soft tissue. The shod rearfoot strike showed a 93% lower damping coefficient than the shod forefoot strike (p<0.001). A lower damping coefficient indicates less damping of the vibrations. The barefoot forefoot strike showed a trend toward a lower damping coefficient compared to a barefoot rearfoot strike. Running barefoot with a forefoot strike resulted in a significantly lower damping coefficient than a forefoot strike when wearing shoes (p<0.001). The shod rearfoot strike showed lower damping compared to a barefoot rearfoot strike (p<0.001). While rearfoot striking showed lower vibration frequencies in shod and barefoot running, it did not consistently result in lower damping coefficients. This study showed that the use of a preferred movement resulted in lower damping coefficients of running related soft tissue vibrations. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The Roles of Mitochondrial Damage-Associated Molecular Patterns in Diseases

PubMed Central

Nakahira, Kiichi; Hisata, Shu

2015-01-01

Abstract Significance: Mitochondria, vital cellular power plants to generate energy, are involved in immune responses. Mitochondrial damage-associated molecular patterns (DAMPs) are molecules that are released from mitochondria to extracellular space during cell death and include not only proteins but also DNA or lipids. Mitochondrial DAMPs induce inflammatory responses and are critically involved in the pathogenesis of various diseases. Recent Advances: Recent studies elucidate the molecular mechanisms by which mitochondrial DAMPs are released and initiate immune responses by use of genetically modulated cells or animals. Importantly, the levels of mitochondrial DAMPs in patients are often associated with severity and prognosis of human diseases, such as infection, asthma, ischemic heart disease, and cancer. Critical Issues: Although mitochondrial DAMPs can represent proinflammatory molecules in various experimental models, their roles in human diseases may be multifunctional and complex. It remains unclear where and how mitochondrial DAMPs are liberated into extracellular spaces and exert their biological functions particularly in vivo. In addition, while mitochondria can secrete several types of DAMPs during cell death, the interaction of each mitochondrial DAMP (e.g., synergistic effects) remains unclear. Future Directions: Regulation of mitochondrial DAMP-mediated immune responses may be important to alter the progression of human diseases. In addition, measuring mitochondrial DAMPs in patients may be clinically useful as biomarkers to predict prognosis or response to therapies. Further studies of the mechanisms by which mitochondrial DAMPs impact the initiation and progression of diseases may lead to the development of therapeutics specifically targeting this pathway. Antioxid. Redox Signal. 23, 1329–1350. PMID:26067258

Problems of internalization: a button is a button is-not.

PubMed

Rockwell, Shelley

2014-01-01

Analysts hope to help the patient internalize a relationship with the analyst that contrasts with the original archaic object relation. In this paper, the author describes particular difficulties in working with a patient whose defenses and anxieties were bulimic, her movement toward internalization inevitably undone. Several issues are considered: how does the nonsymbolizing patient come to internalize the analyst's understanding, and when this does not hold, what is the nature of the patient's subsequent methods of dispersal? When the patient can maintain connection to the analyst as a good object, even fleetingly, in the depressive position, the possibility of internalization and symbolic communication is increased. © 2014 The Psychoanalytic Quarterly, Inc.

Pectoralis Major Repair With Unicortical Button Fixation And Suture Tape.

PubMed

Sanchez, Anthony; Ferrari, Marcio B; Frangiamore, Salvatore J; Sanchez, George; Kruckeberg, Bradley M; Provencher, Matthew T

2017-06-01

Although injuries of the pectoralis major muscle are generally uncommon, ruptures of the pectoralis major are occasionally seen in younger, more active patients who participate in weightlifting activities. These injuries usually occur during maximal contraction of the muscle, while in extension and external rotation. In the case of a rupture, operative treatment is advocated especially in young, active patients regardless of the chronicity of the injury. Various surgical techniques for reattachment of the avulsed tendon have been described, but bone tunnel and suture anchor repair techniques are most widely used. In this Technical Note, we present our preferred technique for acute pectoralis major rupture repair involving use of cortical buttons for tendon stump-to-bone fixation.

Free Bone Plug Quadriceps Tendon Harvest and Suspensory Button Attachment for Anterior Cruciate Ligament Reconstruction.

PubMed

Todor, Adrian; Caterev, Sergiu; Nistor, Dan Viorel; Khallouki, Youssef

2016-06-01

The most commonly used autografts for anterior cruciate ligament reconstruction are the bone-patellar tendon-bone and hamstring tendons. Each has its advantages and limitations. The bone-patellar tendon-bone autograft can lead to more donor-site morbidity, and the hamstring autograft can be unpredictable in size. The quadriceps tendon, with or without a bone block, has been described as an alternative graft source and has been used especially in revision cases, but in recent years, it has attracted attention even for primary cases. We report a technique for harvesting a free bone quadriceps tendon graft and attaching an extracortical button for femoral fixation for anterior cruciate ligament reconstruction.

Optics survivability support, volume 2

NASA Astrophysics Data System (ADS)

Wild, N.; Simpson, T.; Busdeker, A.; Doft, F.

1993-01-01

This volume of the Optics Survivability Support Final Report contains plots of all the data contained in the computerized Optical Glasses Database. All of these plots are accessible through the Database, but are included here as a convenient reference. The first three pages summarize the types of glass included with a description of the radiation source, test date, and the original data reference. This information is included in the database as a macro button labeled 'LLNL DATABASE'. Following this summary is an Abbe chart showing which glasses are included and where they lie as a function of nu(sub d) and n(sub d). This chart is also callable through the database as a macro button labeled 'ABBEC'.

Tactile Data Entry System

NASA Technical Reports Server (NTRS)

Adams, Richard J.

2015-01-01

The patent-pending Glove-Enabled Computer Operations (GECO) design leverages extravehicular activity (EVA) glove design features as platforms for instrumentation and tactile feedback, enabling the gloves to function as human-computer interface devices. Flexible sensors in each finger enable control inputs that can be mapped to any number of functions (e.g., a mouse click, a keyboard strike, or a button press). Tracking of hand motion is interpreted alternatively as movement of a mouse (change in cursor position on a graphical user interface) or a change in hand position on a virtual keyboard. Programmable vibro-tactile actuators aligned with each finger enrich the interface by creating the haptic sensations associated with control inputs, such as recoil of a button press.

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)

Manifold seal structure for fuel cell stack

DOEpatents

Collins, William P.

1988-01-01

The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

LOW TEMPERATURE CATHODE SUPPORTED ELECTROLYTES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harlan U. Anderson; Fatih Dogan; Vladimir Petrovsky

2002-03-31

This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic Electrical Characterization and testing of Planar Single Cells. This period has continued to address the problem of making dense 1/2 to 5 {micro}m thick dense layers on porous substrates (the cathode LSM). Our current status is that we are making structures of 2-5 cm{sup 2} in area, which consist of either dense YSZ or CGO infiltrated into a 2-5 {micro}m thick 50% porous layer made of either nanoncrystalline CGO or YSZ powder. This composite structure coats a macroporous cathode or anode; which serves asmore » the structural element of the bi-layer structure. These structures are being tested as SOFC elements. A number of structures have been evaluated both as symmetrical and as button cell configuration. Results of this testing indicates that the cathodes contribute the most to cell losses for temperatures below 750 C. In this investigation different cathode materials were studied using impedance spectroscopy of symmetric cells and IV characteristics of anode supported fuel cells. Cathode materials studied included La{sub 0.8}Sr{sub 0.2}Co{sub 0.2}Fe{sub 0.8}O{sub 3} (LSCF), La{sub 0.7}Sr{sub 0.2}MnO{sub 3} (LSM), Pr{sub 0.8}Sr{sub 0.2}Fe{sub 0.8}O{sub 3} (PSCF), Sm{sub 0.8}Sr{sub 0.2}Co{sub 0.2}Fe{sub 0.8}O{sub 3} (SSCF), and Yb{sub .8}Sr{sub 0.2}Co{sub 0.2}Fe{sub 0.8}O{sub 3} (SSCF). A new technique for filtering the Fourier transform of impedance data was used to increase the sensitivity of impedance analysis. By creating a filter specifically for impedance spectroscopy the resolution was increased. The filter was tailored to look for specific circuit elements like R//C, Warburg, or constant phase elements. As many as four peaks can be resolved using the filtering technique on symmetric cells. It may be possible to relate the different peaks to material parameters, like the oxygen exchange coefficient. The cathode grouped in order from lowest to highest ASR is LSCF < PSCF < SSCF < YSCF < LSM. The button cell results agree with this ordering indicating that this is an important tool for use in developing our understanding of electrode behavior in fuel cells.« less

Study of Damped Set-Back Pins for S and A Mechanisms.

DTIC Science & Technology

1976-11-01

arm device for artillery munitions. This damped set-back pin assembly is one of two safety features on a S and A device used in the M739 PD/XM587 ET...The damped set-back pin study program was for the design, testing, fabrication, and delivery and damped set-back pin assemblies for use in a safe and...fuzes for a rotating projectile. A pin, porous disc, return spring, floating O-ring, and sleeve comprise the selected damped set-back pin assembly

A Novel Scheme and Evaluations on a Long-Term and Continuous Biosensor Platform Integrated with a Dental Implant Fixture and Its Prosthetic Abutment

PubMed Central

Li, Yu-Jung; Lu, Chih-Cheng

2015-01-01

A miniature intra-oral dental implant system including a built-in biosensor device is proposed in this article. The dental implant system, or platform, is replaced over maxilla and allows relatively non-invasive procedures for a novel biosensing scheme for human blood analysis. Due to placement of the implant fixture, periodontal ligaments and the pulp structure, which are regarded as the main origin of pain, are thus removed, and long-term, continuous blood analysis and management through maxillary bone marrow becomes achievable through the dental implant platform. The new pathway of biological sensing is for the first time presented to realize an accurate and painless approach without injections. The dental implant system mainly consists of an implant fixture and a prosthetic abutment, a biosensor module, a bluetooth 4.0 wireless module and a dc button cell battery. The electrochemical biosensor possesses three electrodes, including working, reference and counter ones, which are arranged to pass through the titanium implant fixture below the biosensor module. The electrodes are exposed to the blood pool inside the maxillary bone marrow and perform oxidation/reduction reactions with the coating of biosensing enzyme. To prove the proposed platform, the immobilization process of glucose oxidase (GOD) enzyme and in vitro detections of glucose levels are successfully carried out, and proven sensitivity, linearity and repeatability of the glucose biosensor system are obtained. Moreover, a preliminary canine animal model adopting the new pathway shows significant consistency with the traditional method through dermal pricks for blood sugar detection. Despite the prospective results, further challenges in engineering implementation and clinical practices are addressed and discussed. In brief, the novel biosensing pathway and intra-oral biosensor platform may increasingly reveal their promising value and feasibilities in current bio-medical analysis, diagnosis, drug release and even healthcare technologies. PMID:26404283

A Novel Scheme and Evaluations on a Long-Term and Continuous Biosensor Platform Integrated with a Dental Implant Fixture and Its Prosthetic Abutment.

PubMed

Li, Yu-Jung; Lu, Chih-Cheng

2015-09-25

A miniature intra-oral dental implant system including a built-in biosensor device is proposed in this article. The dental implant system, or platform, is replaced over maxilla and allows relatively non-invasive procedures for a novel biosensing scheme for human blood analysis. Due to placement of the implant fixture, periodontal ligaments and the pulp structure, which are regarded as the main origin of pain, are thus removed, and long-term, continuous blood analysis and management through maxillary bone marrow becomes achievable through the dental implant platform. The new pathway of biological sensing is for the first time presented to realize an accurate and painless approach without injections. The dental implant system mainly consists of an implant fixture and a prosthetic abutment, a biosensor module, a bluetooth 4.0 wireless module and a dc button cell battery. The electrochemical biosensor possesses three electrodes, including working, reference and counter ones, which are arranged to pass through the titanium implant fixture below the biosensor module. The electrodes are exposed to the blood pool inside the maxillary bone marrow and perform oxidation/reduction reactions with the coating of biosensing enzyme. To prove the proposed platform, the immobilization process of glucose oxidase (GOD) enzyme and in vitro detections of glucose levels are successfully carried out, and proven sensitivity, linearity and repeatability of the glucose biosensor system are obtained. Moreover, a preliminary canine animal model adopting the new pathway shows significant consistency with the traditional method through dermal pricks for blood sugar detection. Despite the prospective results, further challenges in engineering implementation and clinical practices are addressed and discussed. In brief, the novel biosensing pathway and intra-oral biosensor platform may increasingly reveal their promising value and feasibilities in current bio-medical analysis, diagnosis, drug release and even healthcare technologies.

System identification of analytical models of damped structures

NASA Technical Reports Server (NTRS)

Fuh, J.-S.; Chen, S.-Y.; Berman, A.

1984-01-01

A procedure is presented for identifying linear nonproportionally damped system. The system damping is assumed to be representable by a real symmetric matrix. Analytical mass, stiffness and damping matrices which constitute an approximate representation of the system are assumed to be available. Given also are an incomplete set of measured natural frequencies, damping ratios and complex mode shapes of the structure, normally obtained from test data. A method is developed to find the smallest changes in the analytical model so that the improved model can exactly predict the measured modal parameters. The present method uses the orthogonality relationship to improve mass and damping matrices and the dynamic equation to find the improved stiffness matrix.

Damping Estimation from Free Decay Responses of Cables with MR Dampers.

PubMed

Weber, Felix; Distl, Hans

2015-01-01

This paper discusses the damping measurements on cables with real-time controlled MR dampers that were performed on a laboratory scale single strand cable and on cables of the Sutong Bridge, China. The control approach aims at producing amplitude and frequency independent cable damping which is confirmed by the tests. The experimentally obtained cable damping in comparison to the theoretical value due to optimal linear viscous damping reveals that support conditions of the cable anchors, force tracking errors in the actual MR damper force, energy spillover to higher modes, and excitation and sensor cables hanging on the stay cable must be taken into consideration for the interpretation of the identified cable damping values.

Damping Estimation from Free Decay Responses of Cables with MR Dampers

PubMed Central

Weber, Felix; Distl, Hans

2015-01-01

This paper discusses the damping measurements on cables with real-time controlled MR dampers that were performed on a laboratory scale single strand cable and on cables of the Sutong Bridge, China. The control approach aims at producing amplitude and frequency independent cable damping which is confirmed by the tests. The experimentally obtained cable damping in comparison to the theoretical value due to optimal linear viscous damping reveals that support conditions of the cable anchors, force tracking errors in the actual MR damper force, energy spillover to higher modes, and excitation and sensor cables hanging on the stay cable must be taken into consideration for the interpretation of the identified cable damping values. PMID:26167537

Damping measurements in flowing water

NASA Astrophysics Data System (ADS)

Coutu, A.; Seeley, C.; Monette, C.; Nennemann, B.; Marmont, H.

2012-11-01

Fluid-structure interaction (FSI), in the form of mass loading and damping, governs the dynamic response of water turbines, such as Francis turbines. Water added mass and damping are both critical quantities in evaluating the dynamic response of the turbine component. Although the effect of fluid added mass is well documented, fluid damping, a critical quantity to limit vibration amplitudes during service, and therefore to help avoiding possible failure of the turbines, has received much less attention in the literature. This paper presents an experimental investigation of damping due to FSI. The experimental setup, designed to create dynamic characteristics similar to the ones of Francis turbine blades is discussed, together with the experimental protocol and examples of measurements obtained. The paper concludes with the calculated damping values and a discussion on the impact of the observed damping behaviour on the response of hydraulic turbine blades to FSI.

Predicting the effectiveness of viscoelastic damping pockets in beams

NASA Astrophysics Data System (ADS)

Butler, Nigel D.; Oyadiji, S. O.

2005-05-01

This paper looks at the use of viscoelastic damping pockets in the suppression of structural vibration. These are in the form of cavities filled with a viscoelastic material. The benefits and uses of these designed-in damping treatments are highlighted. The vibration responses of viscoelastically-damped beams are predicted using the finite element method. A series of cantilevered beams are considered and the damping performance of several configurations of designed-in dampers are predicted and compared to that of a traditional CLD treatment. It is shown that the effectiveness of the damping pockets and sinks depends on their location and size with respect to the highly stressed regions of the beams. Although there is a practical limit on the sizes of the geometrical features that can be designed-in, it is shown that if located correctly the damping pockets and sinks can be more effective at suppressing structural vibration than traditional CLD treatments.

Special class of nonlinear damping models in flexible space structures

NASA Technical Reports Server (NTRS)

Hu, Anren; Singh, Ramendra P.; Taylor, Lawrence W.

1991-01-01

A special class of nonlinear damping models is investigated in which the damping force is proportional to the product of positive integer or the fractional power of the absolute values of displacement and velocity. For a one-degree-of-freedom system, the classical Krylov-Bogoliubov 'averaging' method is used, whereas for a distributed system, both an ad hoc perturbation technique and the finite difference method are employed to study the effects of nonlinear damping. The results are compared with linear viscous damping models. The amplitude decrement of free vibration for a single mode system with nonlinear models depends not only on the damping ratio but also on the initial amplitude, the time to measure the response, the frequency of the system, and the powers of displacement and velocity. For the distributed system, the action of nonlinear damping is found to reduce the energy of the system and to pass energy to lower modes.

Damping in high-temperature superconducting levitation systems

DOEpatents

Hull, John R [Sammamish, WA

2009-12-15

Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

Damped transverse oscillations of interacting coronal loops

NASA Astrophysics Data System (ADS)

Soler, Roberto; Luna, Manuel

2015-10-01

Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations. Here we theoretically investigate resonantly damped transverse oscillations of interacting nonuniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. Analytic and numerical results in the specific case of two interacting loops are given as an application.

Three-player quantum Kolkata restaurant problem under decoherence

NASA Astrophysics Data System (ADS)

Ramzan, M.

2013-01-01

Effect of quantum decoherence in a three-player quantum Kolkata restaurant problem is investigated using tripartite entangled qutrit states. Different qutrit channels such as, amplitude damping, depolarizing, phase damping, trit-phase flip and phase flip channels are considered to analyze the behaviour of players payoffs. It is seen that Alice's payoff is heavily influenced by the amplitude damping channel as compared to the depolarizing and flipping channels. However, for higher level of decoherence, Alice's payoff is strongly affected by depolarizing noise. Whereas the behaviour of phase damping channel is symmetrical around 50% decoherence. It is also seen that for maximum decoherence ( p = 1), the influence of amplitude damping channel dominates over depolarizing and flipping channels. Whereas, phase damping channel has no effect on the Alice's payoff. Therefore, the problem becomes noiseless at maximum decoherence in case of phase damping channel. Furthermore, the Nash equilibrium of the problem does not change under decoherence.

Research on damping properties optimization of variable-stiffness plate

NASA Astrophysics Data System (ADS)

Wen-kai, QI; Xian-tao, YIN; Cheng, SHEN

2016-09-01

This paper investigates damping optimization design of variable-stiffness composite laminated plate, which means fibre paths can be continuously curved and fibre angles are distinct for different regions. First, damping prediction model is developed based on modal dissipative energy principle and verified by comparing with modal testing results. Then, instead of fibre angles, the element stiffness and damping matrixes are translated to be design variables on the basis of novel Discrete Material Optimization (DMO) formulation, thus reducing the computation time greatly. Finally, the modal damping capacity of arbitrary order is optimized using MMA (Method of Moving Asymptotes) method. Meanwhile, mode tracking technique is employed to investigate the variation of modal shape. The convergent performance of interpolation function, first order specific damping capacity (SDC) optimization results and variation of modal shape in different penalty factor are discussed. The results show that the damping properties of the variable-stiffness plate can be increased by 50%-70% after optimization.

Damping scaling factors for elastic response spectra for shallow crustal earthquakes in active tectonic regions: "average" horizontal component

USGS Publications Warehouse

Rezaeian, Sanaz; Bozorgnia, Yousef; Idriss, I.M.; Abrahamson, Norman; Campbell, Kenneth; Silva, Walter

2014-01-01

Ground motion prediction equations (GMPEs) for elastic response spectra are typically developed at a 5% viscous damping ratio. In reality, however, structural and nonstructural systems can have other damping ratios. This paper develops a new model for a damping scaling factor (DSF) that can be used to adjust the 5% damped spectral ordinates predicted by a GMPE for damping ratios between 0.5% to 30%. The model is developed based on empirical data from worldwide shallow crustal earthquakes in active tectonic regions. Dependencies of the DSF on potential predictor variables, such as the damping ratio, spectral period, ground motion duration, moment magnitude, source-to-site distance, and site conditions, are examined. The strong influence of duration is captured by the inclusion of both magnitude and distance in the DSF model. Site conditions show weak influence on the DSF. The proposed damping scaling model provides functional forms for the median and logarithmic standard deviation of DSF, and is developed for both RotD50 and GMRotI50 horizontal components. A follow-up paper develops a DSF model for vertical ground motion.

Analysis of thermoelastic damping in laminated composite micromechanical beam resonators

NASA Astrophysics Data System (ADS)

Vengallatore, Srikar

2005-12-01

Minimization of structural damping is an essential requirement in the design of multifunctional composite micromachined resonators used for sensing and communications applications. Here, we study thermoelastic damping in symmetric, three-layered, laminated, micromechanical Euler-Bernoulli beams using an analytical framework developed by Bishop and Kinra in 1997. The frequency dependence of damping in two representative sets of structures—metallized ceramic beams and ceramic/ceramic laminates—is investigated in detail. The effects of material properties and relative volume fractions are numerically evaluated. The results indicate that metallization of Si and SiC beams using Al, Cu, Ag or Au leads to a considerable increase in damping over a broad frequency range. Similarly, coating silicon with SiC leads to a monotonic increase of the peak damping value as a function of the volume fraction of silicon carbide but, remarkably, there exists a range of frequencies at which the damping in the composite is less than that of bare silicon. Implications for the design of metallized ceramic beams, and for the simultaneous optimization of natural frequency and damping, are discussed.

Application of viscous and Iwan modal damping models to experimental measurements from bolted structures

DOE PAGES

Deaner, Brandon J.; Allen, Matthew S.; Starr, Michael James; ...

2015-01-20

Measurements are presented from a two-beam structure with several bolted interfaces in order to characterize the nonlinear damping introduced by the joints. The measurements (all at force levels below macroslip) reveal that each underlying mode of the structure is well approximated by a single degree-of-freedom (SDOF) system with a nonlinear mechanical joint. At low enough force levels, the measurements show dissipation that scales as the second power of the applied force, agreeing with theory for a linear viscously damped system. This is attributed to linear viscous behavior of the material and/or damping provided by the support structure. At larger forcemore » levels, the damping is observed to behave nonlinearly, suggesting that damping from the mechanical joints is dominant. A model is presented that captures these effects, consisting of a spring and viscous damping element in parallel with a four-parameter Iwan model. As a result, the parameters of this model are identified for each mode of the structure and comparisons suggest that the model captures the stiffness and damping accurately over a range of forcing levels.« less

Structural dynamics and vibrations of damped, aircraft-type structures

NASA Technical Reports Server (NTRS)

Young, Maurice I.

1992-01-01

Engineering preliminary design methods for approximating and predicting the effects of viscous or equivalent viscous-type damping treatments on the free and forced vibration of lightly damped aircraft-type structures are developed. Similar developments are presented for dynamic hysteresis viscoelastic-type damping treatments. It is shown by both engineering analysis and numerical illustrations that the intermodal coupling of the undamped modes arising from the introduction of damping may be neglected in applying these preliminary design methods, except when dissimilar modes of these lightly damped, complex aircraft-type structures have identical or nearly identical natural frequencies. In such cases, it is shown that a relatively simple, additional interaction calculation between pairs of modes exhibiting this 'modal response' phenomenon suffices in the prediction of interacting modal damping fractions. The accuracy of the methods is shown to be very good to excellent, depending on the normal natural frequency separation of the system modes, thereby permitting a relatively simple preliminary design approach. This approach is shown to be a natural precursor to elaborate finite element, digital computer design computations in evaluating the type, quantity, and location of damping treatment.

Quantum Landau damping in dipolar Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Mendonça, J. T.; Terças, H.; Gammal, A.

2018-06-01

We consider Landau damping of elementary excitations in Bose-Einstein condensates (BECs) with dipolar interactions. We discuss quantum and quasiclassical regimes of Landau damping. We use a generalized wave-kinetic description of BECs which, apart from the long-range dipolar interactions, also takes into account the quantum fluctuations and the finite-energy corrections to short-range interactions. Such a description is therefore more general than the usual mean-field approximation. The present wave-kinetic approach is well suited for the study of kinetic effects in BECs, such as those associated with Landau damping, atom trapping, and turbulent diffusion. The inclusion of quantum fluctuations and energy corrections changes the dispersion relation and the damping rates, leading to possible experimental signatures of these effects. Quantum Landau damping is described with generality, and particular examples of dipolar condensates in two and three dimensions are studied. The occurrence of roton-maxon excitations, and their relevance to Landau damping, are also considered in detail. The present approach is mainly based on a linear perturbative procedure, but the nonlinear regime of Landau damping, which includes atom trapping and atom diffusion, is also briefly discussed.

Flux-driven algebraic damping of m=2 diocotron mode

NASA Astrophysics Data System (ADS)

Chim, C. Y.; O'Neil, T. M.

2016-10-01

Recent experiments with pure electron plasmas in a Malmberg-Penning trap have observed the algebraic damping of m = 2 diocotron modes. Due to small field asymmetries a low density halo of electrons is transported radially outward from the plasma core, and the mode damping begins when the halo reaches the resonant radius rres, where f = mfE × B (rres) . The damping rate is proportional to the flux of halo particles through the resonant layer. The damping is related to, but distinct from the exponential spatial Landau damping in a linear wave-particle resonance. This poster uses analytic theory and simulations to explain the new flux-driven algebraic damping of the mode. As electrons are swept around the nonlinear ``cat's eye'' orbits of the resonant wave-particle interaction, they form a quadrupole (m = 2) density distribution, which sets up an electric field that acts back on the plasma core. The field causes an E × B drift motion that symmetrizes the core, i.e. damps the m = 2 mode. Supported by NSF Grant PHY-1414570, and DOE Grants DE-SC0002451.

Vibration Reduction of Helicopter Blade Using Variable Dampers: A Feasibility Study

NASA Technical Reports Server (NTRS)

Lee, George C.; Liang, Zach; Gan, Quan; Niu, Tiecheng

2002-01-01

In the report, the investigation of controlling helicopter-blade lead-lag vibration is described. Current practice of adding passive damping may be improved to handle large dynamic range of the blade with several peaks of vibration resonance. To minimize extra-large damping forces that may damage the control system of blade, passive dampers should have relatively small damping coefficients, which in turn limit the effectiveness. By providing variable damping, a much larger damping coefficient to suppress the vibration can be realized. If the damping force reaches the maximum allowed threshold, the damper will be automatically switched into the mode with smaller damping coefficient to maintain near-constant damping force. Furthermore, the proposed control system will also have a fail-safe feature to guarantee the basic performation of a typical passive damper. The proposed control strategy to avoid resonant regions in the frequency domain is to generate variable damping force in combination with the supporting stiffness to manipulate the restoring force and conservative energy of the controlled blade system. Two control algorithms are developed and verified by a prototype variable damper, a digital controller and corresponding algorithms. Primary experiments show good potentials for the proposed variable damper: about 66% and 82% reductions in displacement at 1/3 length and the root of the blade respectively.

Enhancing the Damping Behavior of Dilute Zn-0.3Al Alloy by Equal Channel Angular Pressing

NASA Astrophysics Data System (ADS)

Demirtas, M.; Atli, K. C.; Yanar, H.; Purcek, G.

2017-06-01

The effect of grain size on the damping capacity of a dilute Zn-0.3Al alloy was investigated. It was found that there was a critical strain value (≈1 × 10-4) below and above which damping of Zn-0.3Al showed dynamic and static/dynamic hysteresis behavior, respectively. In the dynamic hysteresis region, damping resulted from viscous sliding of phase/grain boundaries, and decreasing grain size increased the damping capacity. While the quenched sample with 100 to 250 µm grain size showed very limited damping capacity with a loss factor tanδ of less than 0.007, decreasing grain size down to 2 µm by equal channel angular pressing (ECAP) increased tanδ to 0.100 in this region. Dynamic recrystallization due to microplasticity at the sample surface was proposed as the damping mechanism for the first time in the region where the alloy showed the combined aspects of dynamic and static hysteresis damping. In this region, tanδ increased with increasing strain amplitude, and ECAPed sample showed a tanδ value of 0.256 at a strain amplitude of 2 × 10-3, the highest recorded so far in the damping capacity-related studies on ZA alloys.

Analysis of dry friction damping characteristics for short cylindrical shell structures

NASA Astrophysics Data System (ADS)

Wang, Nengmao; Wang, Yanrong

2018-05-01

An efficient mathematical model to describe the friction of short cylindrical shell structures with a dry friction damping sleeve is proposed. The frictional force in the circumference and axial direction is caused by the opposing bending strains at the interface. Slipping will occur at part region of the interface and the mathematic model of the slipping region is established. Ignoring the effect of contact stiffness on the vibration analysis, the friction energy dissipation capability of damping sleeve would be calculated. Structural vibration mode, positive pressure at the interface and vibration stress of the short cylindrical shell structures is analyzed as influence factors to the critical damping ratio. The results show that the circumferential friction energy dissipation is more sensitive to the number of nodal diameter, and the circumferential friction damping ratio increases rapidly with the number of nodal diameter. The slipping frictional force would increase along with the positive pressure, but the slipping region would decrease with it. The peak damping ratio keeps nearly constant. But the vibration stress corresponding to peak damping ratio would increases with the positive pressure. The dry friction damping ratio of damping sleeve contains the effect of frictional force in the circumference and axial direction, and the axial friction plays a major role.

Introduction to the scientific application system of DAMPE (On behalf of DAMPE collaboration)

NASA Astrophysics Data System (ADS)

Zang, Jingjing

2016-07-01

The Dark Matter Particle Explorer (DAMPE) is a high energy particle physics experiment satellite, launched on 17 Dec 2015. The science data processing and payload operation maintenance for DAMPE will be provided by the DAMPE Scientific Application System (SAS) at the Purple Mountain Observatory (PMO) of Chinese Academy of Sciences. SAS is consisted of three subsystems - scientific operation subsystem, science data and user management subsystem and science data processing subsystem. In cooperation with the Ground Support System (Beijing), the scientific operation subsystem is responsible for proposing observation plans, monitoring the health of satellite, generating payload control commands and participating in all activities related to payload operation. Several databases developed by the science data and user management subsystem of DAMPE methodically manage all collected and reconstructed science data, down linked housekeeping data, payload configuration and calibration data. Under the leadership of DAMPE Scientific Committee, this subsystem is also responsible for publication of high level science data and supporting all science activities of the DAMPE collaboration. The science data processing subsystem of DAMPE has already developed a series of physics analysis software to reconstruct basic information about detected cosmic ray particle. This subsystem also maintains the high performance computing system of SAS to processing all down linked science data and automatically monitors the qualities of all produced data. In this talk, we will describe all functionalities of whole DAMPE SAS system and show you main performances of data processing ability.

Advances in Ceramic Matrix Composite Blade Damping Characteristics for Aerospace Turbomachinery Applications

NASA Technical Reports Server (NTRS)

Min, James B.; Harris, Donald L.; Ting, J. M.

2011-01-01

For advanced aerospace propulsion systems, development of ceramic matrix composite integrally-bladed turbine disk technology is attractive for a number of reasons. The high strength-to-weight ratio of ceramic composites helps to reduce engine weight and the one-piece construction of a blisk will result in fewer parts count, which should translate into reduced operational costs. One shortcoming with blisk construction, however, is that blisks may be prone to high cycle fatigue due to their structural response to high vibration environments. Use of ceramic composites is expected to provide some internal damping to reduce the vibratory stresses encountered due to unsteady flow loads through the bladed turbine regions. A goal of our research was to characterize the vibration viscous damping behavior of C/SiC composites. The vibration damping properties were measured and calculated. Damping appeared to decrease with an increase in the natural frequency. While the critical damping amount of approximately 2% is required for typical aerospace turbomachinery engines, the C/SiC damping at high frequencies was less than 0.2% from our study. The advanced high-performance aerospace propulsion systems almost certainly will require even more damping than what current vehicles require. A purpose of this paper is to review some work on C/SiC vibration damping by the authors for the NASA CMC turbine blisk development program and address an importance of the further investigation of the blade vibration damping characteristics on candidate CMC materials for the NASA s advanced aerospace turbomachinery engine systems.

Design of passive piezoelectric damping for space structures. Final Report Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Hagood, Nesbitt W., IV; Aldrich, Jack B.; Vonflotow, Andreas H.

1994-01-01

Passive damping of structural dynamics using piezoceramic electromechanical energy conversion and passive electrical networks is a relatively recent concept with little implementation experience base. This report describes an implementation case study, starting from conceptual design and technique selection, through detailed component design and testing to simulation on the structure to be damped. About 0.5kg. of piezoelectric material was employed to damp the ASTREX testbed, a 500kg structure. Emphasis was placed upon designing the damping to enable high bandwidth robust feedback control. Resistive piezoelectric shunting provided the necessary broadband damping. The piezoelectric element was incorporated into a mechanically-tuned vibration absorber in order to concentrate damping into the 30 to 40 Hz frequency modes at the rolloff region of the proposed compensator. A prototype of a steel flex-tensional motion amplification device was built and tested. The effective stiffness and damping of the flex-tensional device was experimentally verified. When six of these effective springs are placed in an orthogonal configuration, strain energy is absorbed from all six degrees of freedom of a 90kg. mass. A NASTRAN finite element model of the testbed was modified to include the six-spring damping system. An analytical model was developed for the spring in order to see how the flex-tensional device and piezoelectric dimensions effect the critical stress and strain energy distribution throughout the component. Simulation of the testbed demonstrated the damping levels achievable in the completed system.

Modelling and Vibration Control of Beams with Partially Debonded Active Constrained Layer Damping Patch

NASA Astrophysics Data System (ADS)

SUN, D.; TONG, L.

2002-05-01

A detailed model for the beams with partially debonded active constraining damping (ACLD) treatment is presented. In this model, the transverse displacement of the constraining layer is considered to be non-identical to that of the host structure. In the perfect bonding region, the viscoelastic core is modelled to carry both peel and shear stresses, while in the debonding area, it is assumed that no peel and shear stresses be transferred between the host beam and the constraining layer. The adhesive layer between the piezoelectric sensor and the host beam is also considered in this model. In active control, the positive position feedback control is employed to control the first mode of the beam. Based on this model, the incompatibility of the transverse displacements of the active constraining layer and the host beam is investigated. The passive and active damping behaviors of the ACLD patch with different thicknesses, locations and lengths are examined. Moreover, the effects of debonding of the damping layer on both passive and active control are examined via a simulation example. The results show that the incompatibility of the transverse displacements is remarkable in the regions near the ends of the ACLD patch especially for the high order vibration modes. It is found that a thinner damping layer may lead to larger shear strain and consequently results in a larger passive and active damping. In addition to the thickness of the damping layer, its length and location are also key factors to the hybrid control. The numerical results unveil that edge debonding can lead to a reduction of both passive and active damping, and the hybrid damping may be more sensitive to the debonding of the damping layer than the passive damping.

Validity of Miles Equation in Predicting Propellant Slosh Damping in Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2018-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involves the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations were mainly carried out by extensive experiments. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between the empirical Miles equation and experimental measurements, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use Computational Fluid Dynamics (CFD) technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. Loci-STREAM-VOF, a well validated CFD solver developed at NASA MSFC, is applied to study the vorticity field around a baffle and around the fluid-gas interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data is then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (d/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

Validation of High-Resolution CFD Method for Slosh Damping Extraction of Baffled Tanks

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involve the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations and knowledge were mainly carried out by extensive experimental studies. A Volume-Of-Fluid (VOF) based CFD program developed at NASA MSFC was applied to extract slosh damping in a baffled tank from the first principle. First, experimental data using water with subscale smooth wall tank were used as the baseline validation. CFD simulation was demonstrated to be capable of accurately predicting natural frequency and very low damping value from the smooth wall tank at different fill levels. The damping due to a ring baffle at different liquid fill levels from barrel section and into the upper dome was then investigated to understand the slosh damping physics due to the presence of a ring baffle. Based on this study, the Root-Mean-Square error of our CFD simulation in estimating slosh damping was less than 4.8%, and the maximum error was less than 8.5%. Scalability of subscale baffled tank test using water was investigated using the validated CFD tool, and it was found that unlike the smooth wall case, slosh damping with baffle is almost independent of the working fluid and it is reasonable to apply water test data to the full scale LOX tank when the damping from baffle is dominant. On the other hand, for the smooth wall, the damping value must be scaled according to the Reynolds number. Comparison of experimental data, CFD, with the classical and modified Miles equations for upper dome was made, and the limitations of these semi-empirical equations were identified.

Associations between home dampness-related exposures and childhood eczema among 13,335 preschool children in Shanghai, China: A cross-sectional study.

PubMed

Cai, Jiao; Liu, Wei; Hu, Yu; Zou, Zhijun; Shen, Li; Huang, Chen

2016-04-01

From April 2011 to April 2012, we conducted a cross-sectional study in Shanghai, China. A total of 13,335 modified ISAAC questionnaires (response rate: 85.3%) were returned by parents or guardians for 4-6 year-old children. Six dampness-related indicators (visible mold spots, visible damp stains, damp bed clothing, water damage, window pane condensation, and moldy odor) were used to evaluate home dampness-related exposures. In the present study, we applied logistic regression model to reveal associations, dose-response relationships, and statistical interaction effects of these dampness-related exposures, with childhood eczema, during lifetime since birth (ever) and in the last 12 months before the questionnaire. The dampness-related indicators were frequently reported in the perinatal and current residences. Prevalences of eczema ever and in the last 12 months were 22.9% and 13.2%, respectively. The dampness-related indicators were robustly associated and dose-response related with increased risk of eczema ever and in the last 12 months in the logistic regression analyses, with adjusted for potential confounders. Specifically, in the perinatal residence, visible mold spots or damp stains could increase 46% (OR, 95% CI: 1.46, 1.29-1.66) odds of childhood eczema (ever); in the current residence, visible mold spots and visible damp stains could increase 34% (1.34, 1.14-1.58) and 38% (1.38, 1.22-1.56) odds of childhood eczema (ever), respectively. Associations were not appreciably different between boys and girls, nor were they different between children with and without parental history of atopy. In conclusion, perinatal and current dampness-related exposures in the residence perhaps are risk factors for childhood eczema. Copyright © 2015 Elsevier Inc. All rights reserved.

Optimization and performance comparison for galloping-based piezoelectric energy harvesters with alternating-current and direct-current interface circuits

NASA Astrophysics Data System (ADS)

Tan, Ting; Yan, Zhimiao; Lei, Hong

2017-07-01

Galloping-based piezoelectric energy harvesters scavenge small-scale wind energy and convert it into electrical energy. For piezoelectric energy harvesting with the same vibrational source (galloping) but different (alternating-current (AC) and direct-current (DC)) interfaces, general analytical solutions of the electromechanical coupled distributed parameter model are proposed. Galloping is theoretically proven to appear when the linear aerodynamic negative damping overcomes the electrical damping and mechanical damping. The harvested power is demonstrated as being done by the electrical damping force. Via tuning the load resistance to its optimal value for optimal or maximal electrical damping, the harvested power of the given structure with the AC/DC interface is maximized. The optimal load resistances and the corresponding performances of such two systems are compared. The optimal electrical damping are the same but with different optimal load resistances for the systems with the AC and DC interfaces. At small wind speeds where the optimal electrical damping can be realized by only tuning the load resistance, the performances of such two energy harvesting systems, including the minimal onset speeds to galloping, maximal harvested powers and corresponding tip displacements are almost the same. Smaller maximal electrical damping with larger optimal load resistance is found for the harvester with the DC interface when compared to those for the harvester with the AC interface. At large wind speeds when the maximal electrical damping rather than the optimal electrical damping can be reached by tuning the load resistance alone, the harvester with the AC interface circuit is recommended for a higher maximal harvested power with a smaller tip displacement. This study provides a method using the general electrical damping to connect and compare the performances of piezoelectric energy harvesters with same excitation source but different interfaces.

Investigation of Damping Physics and CFD Tool Validation for Simulation of Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involves the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations were mainly carried out by extensive experiments. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between the empirical Miles equation and experimental measurements, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use Computational Fluid Dynamics (CFD) technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. Loci-STREAM-VOF, a well validated CFD solver developed at NASA MSFC, is applied to study the vorticity field around a baffle and around the fluid-gas interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data is then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (d/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

Mechanism of failure of the Cabrol procedure: A computational fluid dynamic analysis.

PubMed

Poullis, M; Pullan, M

2015-12-01

Sudden failure of the Cabrol graft is common and frequently fatal. We utilised the technique of computational fluid dynamic (CFD) analysis to evaluate the mechanism of failure and potentially improve on the design of the Cabrol procedure. CFD analysis of the classic Cabrol procedure and a number of its variants was performed. Results from this analysis was utilised to generate further improved geometric options for the Cabrol procedure. These were also subjected to CFD analysis. All current Cabrol and variations of the Cabrol procedure are predicated by CFD analysis to be prone to graft thrombosis, secondary to stasis around the right coronary artery button. The right coronary artery flow characteristics were found to be the dominant reason for Cabrol graft failure. A simple modification of the Cabrol geometry is predicated to virtually eliminate any areas of blood stasis, and graft failure. Modification of the Cabrol graft geometry, due to CFD analysis may help reduce the incidence of graft thrombosis. A C shaped Cabrol graft with the right coronary button anastomosed to its side along its course from the aorta to the left coronary button is predicted to have the least thrombotic tendency. Clinical correlation is needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Grasp specific and user friendly interface design for myoelectric hand prostheses.

PubMed

Mohammadi, Alireza; Lavranos, Jim; Howe, Rob; Choong, Peter; Oetomo, Denny

2017-07-01

This paper presents the design and characterisation of a hand prosthesis and its user interface, focusing on performing the most commonly used grasps in activities of daily living (ADLs). Since the operation of a multi-articulated powered hand prosthesis is difficult to learn and master, there is a significant rate of abandonment by amputees in preference for simpler devices. In choosing so, amputees chose to live with fewer features in their prosthesis that would more reliably perform the basic operations. In this paper, we look simultaneously at a hand prosthesis design method that aims for a small number of grasps, a low complexity user interface and an alternative method to the current use of EMG as a preshape selection method through the use of a simple button; to enable amputees to get to and execute the intended hand movements intuitively, quickly and reliably. An experiment is reported at the end of the paper comparing the speed and accuracy with which able-bodied naive subjects are able to select the intended preshapes through the use of a simplified EMG method and a simple button. It is shown that the button was significantly superior in the speed of successful task completion and marginally superior in accuracy (success of first attempt).

Pandemic Flu

MedlinePlus

... Address What's this? Submit What's this? Submit Button Influenza Types Seasonal Avian Swine Variant Pandemic Other Pandemic Influenza Language: English (US) Español Recommend on Facebook Tweet ...

Diarrhea and Swimming

MedlinePlus

... Health International Recreational Water RWIs, Swimmer Hygiene, & Behavioral Science Historical CDC Manuals Health Promotion Materials Brochures Buttons & Banners Fact Sheets Infographics Clean It Up, Swimmers Make a ...

Evaluation of the potential use of probiotic strain Lactobacillus plantarum 299v in lactic fermentation of button mushroom fruiting bodies.

PubMed

Jabłońska-Ryś, Ewa; Sławińska, Aneta; Radzki, Wojciech; Gustaw, Waldemar

2016-01-01

The available literature does not provide data on the application of probiotic strains in mushroom processing. The aim of the study was to evaluate the potential to use the L. plantarum 299v strain with documented probiotic properties in the process of lactic fermentation of button mushroom fruiting bodies (Agaricus bisporus). Fresh button mushroom fruiting bodies and cultures of lactic acid bacteria L. plantarum Ib and a probiotic strain L. plantarum 299v were the material analysed. Sensory evaluation was performed with a 5-point scale, an instrumental method of colour measurement based on the CIA L*a*b* scale, total phenolic compounds were determined with the Folin method, antioxidant properties were assayed with the DPPH radical test, and reducing power was determined using the FRAP method. After a week-long lactic fermentation, the pH value in the samples declined to a level of 3.6 (L. plantarum Ib) and 3.75 (L. plantarum 299v); these values persisted or decreased slightly during the period of maturation of the fermented samples under refrigeration. Fermented mushrooms were assigned high grades in the organoleptic evaluation. The colour analysis revealed significant changes in the values of the L*a*b* parameters in the fermented product, in comparison with fresh mushrooms. Blanching contributed to a significant decrease in the content of total phenolic compounds in the mushroom fruiting bodies and to a decline in antioxidant activity. Mushrooms fermented with the probiotic strain were characterised by higher phenolic compound content and higher antioxidant activity. L. plantarum 299v strain with documented probiotic properties can be applied in fermentation of button mushroom fruiting bodies. Products obtained with the use of both strains were characterised by good sensory properties. The type of strain used in the lactic fermentation of mushroom fruiting bodies had an effect on the phenolic compound content and antioxidant properties of the final product.

Modeling and test of a kinaesthetic actuator based on MR fluid for haptic applications.

PubMed

Yang, Tae-Heon; Koo, Jeong-Hoi; Kim, Sang-Youn; Kwon, Dong-Soo

2017-03-01

Haptic display units have been widely used for conveying button sensations to users, primarily employing vibrotactile actuators. However, the human feeling for pressing buttons mainly relies on kinaesthetic sensations (rather than vibrotactile sensations), and little studies exist on small-scale kinaesthetic haptic units. Thus, the primary goals of this paper are to design a miniature kinaesthetic actuator based on Magneto-Rheological (MR) fluid that can convey various button-clicking sensations and to experimentally evaluate its haptic performance. The design focuses of the proposed actuator were to produce sufficiently large actuation forces (resistive forces) for human users in a given size constraint and to offer a wide range of actuation forces for conveying vivid haptic sensations to users. To this end, this study first performed a series of parametric studies using mathematical force models for multiple operating modes of MR fluid in conjunction with finite element electromagnetism analysis. After selecting design parameters based on parametric studies, a prototype actuator was constructed, and its performance was evaluated using a dynamic mechanical analyzer. It measured the actuator's resistive force with a varying stroke (pressed depth) up to 1 mm and a varying input current from 0 A to 200 mA. The results show that the proposed actuator creates a wide range of resistive forces from around 2 N (off-state) to over 9.5 N at 200 mA. In order to assess the prototype's performance in the terms of the haptic application prospective, a maximum force rate was calculated to determine just noticeable difference in force changes for the 1 mm stoke of the actuator. The results show that the force rate is sufficient to mimic various levels of button sensations, indicating that the proposed kinaesthetic actuator can offer a wide range of resistive force changes that can be conveyed to human operators.

Identification and topographic localization of metallic foreign bodies by metal detector.

PubMed

Muensterer, Oliver J; Joppich, Ingolf

2004-08-01

Exact localization of ingested metal objects is necessary to guide therapy. This study prospectively evaluates the accuracy of foreign body (FB) identification and localization by metal detector (MTD) in a systematic topographic fashion. Patients who presented after an alleged or witnessed metal FB ingestion were scanned with an MTD. In case of a positive signal, the location was recorded in a topographic diagram, and radiographs were obtained. The diagnostic accuracy of the MTD scan for FB identification and topographic localization was determined by chi(2) analysis, and concordance was calculated by the McNemar test and expressed as kappa. A total of 70 MTD examinations were performed on 65 patients (age 6 months to 16 years); 5 patients were scanned twice on different days. The majority had swallowed coins and button batteries (n = 41). Of these, 29 items were correctly identified, and 11 of 12 were correctly ruled out (coins and button batteries: sensitivity, 100% [95% Confidence Interval 95% to 100%]; specificity, 91.7% [95% CI 76% to 100%], kappa = 0.94). When all metallic objects were included, 41 of 46 were correctly identified, and 22 of 24 were correctly ruled out (sensitivity, 89.1% [95% CI 80% to 98%]; specificity, 91.7% [95% CI 81% to 100%], kappa = 0.78). Five miscellaneous objects were not identified (sensitivity for items other than coins and button batteries 71% [95% CI 49% to 92%], kappa = 0.56). Localization by MTD was correct in 30 of 41 identified objects (73%). The error rates of junior and senior pediatric surgery residents did not differ significantly (P =.82). Ingested coins and button batteries can be safely and accurately found by metal detector. For these indications, the MTD is a radiation-free diagnostic alternative to conventional radiographs. Other items, however, cannot be ruled out reliably by MTD. In these cases, radiographic imaging is still indicated.

[Outcomes and complications of Tightrope button plate for repairing acromioclavicular dislocation].

PubMed

Zuo, Yong-Xiang; Ma, Zi-Ping

2017-10-25

To study the clinical outcome and complications of Tightrope button plate for repairing acromioclavicular dislocation of Rockwood type III to V. From May 2014 to December 2016, 17 patients with acromioclavicular dislocation of type III-V were treated with Tightrope button plate including 10 males and 7 females with an average age 39.8 years old ranging from 20 to 68 years old. Four patients were treated with arthroscopy and 17 patients were treated with mini-invasive by X-ray assisted. Shoulder function, X-ray and complications after operation were assessed. All patients were followed up for 5 to 23 months with a mean of 10.8 months. All patients got satisfying reduction immediately postoperatively. Among them, 1 case of clavicle end wound foreign body reaction, rupture, effusion, healing after the second suture; 1 case of foreign body granuloma formation at the end of clavicle were resected and removed at 4 months after operation; 3 cases loss reduction(less than 50% of acromioclavicular joint). No coracoid fracture and suture breakage observed. The shoulder mobility was restored in 15 cases at 4 to 6 weeks postoperatively, and the shoulder adhesion in 2 cases was delayed to 5 to 7 months after operation. The Constant scores were improved from 46.9±6.0 preoperatively to 92.7±4.0 at the final follow-up. X-ray evaluation of postoperative coracoclavicular tunnel location, patients' coracoclavicular tunnel with mini-invasive fluoroscopy all closed to the ideal position (across the clavicle vertically through the coracoid base center), while different degree of tunnel position deviation were observed in arthroscopic patients. Tightrope button plate for the treatment of acromioclavicular joint dislocation had advantages of minimally invasive, effective, good clinical results, the majority of common complications does not affect efficacy. Small incision X-ray method can provide more satisfactory and reliable tunnel location.

Imaging button battery ingestions and insertions in children: a 15-year single-center review.

PubMed

Pugmire, Brian S; Lin, Tom K; Pentiuk, Scott; de Alarcon, Alessandro; Hart, Catherine K; Trout, Andrew T

2017-02-01

Recent studies have shown an increase in morbidity associated with button battery ingestions in children. To perform a comprehensive, imaging-focused review of all patients with confirmed button battery ingestions/insertions imaged at our institution in the last 15 years. Radiology reports from Jan. 1, 2000, to July 12, 2015, were searched for the terms "battery" and "batteries." Confirmed cases of battery ingestion/insertion for which images were available were reviewed. Cases were reviewed for imaging studies performed, imaging findings, patient demographics, clinical history and management. Two pediatric gastroenterologists reviewed endoscopic images and graded mucosal injuries in selected cases. Two hundred seventy-six cases were reviewed. All patients were imaged with radiography, 19 with fluoroscopy (6.8%), and 4 with CT (1.4%). Batteries retained in the esophagus (n = 27, 9.8%) were larger in diameter on average than those that had passed distally (22.1 ± 3.3 mm vs. 13.7 ± 1.6 mm, P<0.0001). Battery diameter ≥20 mm was associated with esophageal impaction (P<0.0001) and higher grade esophageal injury (P<0.0001). Mean battery diameter was greater for patients with grade 1 or higher mucosal injury than for patients with no mucosal injury (22.1 ± 2.1 mm vs. 14.7 ± 4.5 mm, P<0.0001). Sixteen percent (4/25) of patients with grade ≥1 esophageal injury had batteries in the stomach on initial imaging. Five patients (1.8%) had serious clinical complications (e.g., esophageal perforation, tracheoesophageal fistula). Button batteries >20mm in diameter warrant increased clinical scrutiny due to higher likelihood and severity of injury. Implementation of recent pediatric gastroenterology societal guidelines will likely lead to a substantial increase in the number of CT and MRI examinations.

Damping element for reducing the vibration of an airfoil

DOEpatents

Campbell, Christian X; Marra, John J

2013-11-12

An airfoil (10) is provided with a tip (12) having an opening (14) to a center channel (24). A damping element (16) is inserted within the opening of the center channel, to reduce an induced vibration of the airfoil. The mass of the damping element, a spring constant of the damping element within the center channel, and/or a mounting location (58) of the damping element within the center channel may be adjustably varied, to shift a resonance frequency of the airfoil outside a natural operating frequency of the airfoil.

Evaluation of Nanomaterial Approaches to Damping in Epoxy Resin and Carbon Fiber/Epoxy Composite Structures by Dynamic Mechanical Analysis

NASA Technical Reports Server (NTRS)

Miller, G.; Heimann, Paula J.; Scheiman, Daniel A.; Duffy, Kirsten P.; Johnston, J. Chris; Roberts, Gary D.

2013-01-01

Vibration mitigation in composite structures has been demonstrated through widely varying methods which include both active and passive damping. Recently, nanomaterials have been investigated as a viable approach to composite vibration damping due to the large surface available to generate energy dissipation through friction. This work evaluates the influence of dispersed nanoparticles on the damping ratio of an epoxy matrix. Limited benefit was observed through dispersion methods, however nanoparticle application as a coating resulting in up to a three-fold increase in damping.

Effect of forward speed on the roll damping of three small fishing vessels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haddara, M.R.; Zhang, S.

1994-05-01

An extensive experimental program has been carried out to estimate roll damping parameters for three models of fishing vessels having different hull shapes and moving with forward speed. Roll damping parameters are determined using a novel method. This method combines the energy method and the modulating function method. The effect of forward speed, initial heel angle and the natural frequency on damping is discussed. A modification of Ikeda's formula for lift damping prediction is suggested. The modified formula produces results which are in good agreement with the experiments.

Variable-Force Eddy-Current Damper

NASA Technical Reports Server (NTRS)

Cunningham, R. E.

1986-01-01

Variable damping achieved without problems of containing viscous fluids. Eddy-current damping obtained by moving copper or aluminum conductors through magnetic fields. Position of magnet carrier determines amount of field engagement and, therefore, amount of damping. Three advantages of concept: Magnitudes of stiffness and damping continously varied from maximum to zero without bringing rotor or shaft to stop; used in rotating machines not having viscous fluids available such as lubricating oils; produces sizable damping forces in machines that pump liquid hydrogen at - 246 degrees C and liquid oxygen at - 183 degrees C and are compact in size.

Dynamic analysis to evaluate viscoelastic passive damping augmentation for the Space Shuttle Remote Manipulator System

NASA Technical Reports Server (NTRS)

Alberts, Thomas E.; Xia, Houchun; Chen, Yung

1992-01-01

The effectiveness of constrained viscoelastic layer damping treatment designs is evaluated separately as passive control measures for low frequency joint dominated modes and higher frequency boom flexure dominated modes using a NASTRAN finite element analysis. Passive damping augmentation is proposed which is based on a constrained viscoelastic layer damping treatment applied to the surface of the manipulators's flexible booms. It is pointed out that even the joint compliance dominated modes can be damped to some degree through appropriate design of the treatment.

Anomalous Damping of a Microelectromechanical Oscillator in Superfluid ^{3}He-B.

PubMed

Zheng, P; Jiang, W G; Barquist, C S; Lee, Y; Chan, H B

2016-11-04

The mechanical resonance properties of a microelectromechanical oscillator with a gap of 1.25  μm was studied in superfluid ^{3}He-B at various pressures. The oscillator was driven in the linear damping regime where the damping coefficient is independent of the oscillator velocity. The quality factor of the oscillator remains low (Q≈80) down to 0.1T_{c}, 4 orders of magnitude less than the intrinsic quality factor measured in vacuum at 4 K. In addition to the Boltzmann temperature dependent contribution to the damping, a damping proportional to temperature was found to dominate at low temperatures. We propose a multiple scattering mechanism of the surface Andreev bound states to be a possible cause for the anomalous damping.

Turbojet engine blade damping

NASA Technical Reports Server (NTRS)

Srinivasan, A. V.; Cutts, D. G.; Sridhar, S.

1981-01-01

The potentials of various sources of nonaerodynamic damping in engine blading are evaluated through a combination of advanced analysis and testing. The sources studied include material hysteresis, dry friction at shroud and root disk interfaces as well as at platform type external dampers. A limited seris of tests was conducted to evaluate damping capacities of composite materials (B/AL, B/AL/Ti) and thermal barrier coatings. Further, basic experiments were performed on titanium specimens to establish the characteristics of sliding friction and to determine material damping constants J and n. All the tests were conducted on single blades. Mathematical models were develthe several mechanisms of damping. Procedures to apply this data to predict damping levels in an assembly of blades are developed and discussed.

The Pharmaceutical Capping Process-Correlation between Residual Seal Force, Torque Moment, and Flip-off Removal Force.

PubMed

Mathaes, Roman; Mahler, Hanns-Christian; Vorgrimler, Lothar; Steinberg, Henrik; Dreher, Sascha; Roggo, Yves; Nieto, Alejandra; Brown, Helen; Roehl, Holger; Adler, Michael; Luemkemann, Joerg; Huwyler, Joerg; Lam, Philippe; Stauch, Oliver; Mohl, Silke; Streubel, Alexander

2016-01-01

The majority of parenteral drug products are manufactured in glass vials with an elastomeric rubber stopper and a crimp cap. The vial sealing process is a critical process step during fill-and-finish operations, as it defines the seal quality of the final product. Different critical capping process parameters can affect rubber stopper defects, rubber stopper compression, container closure integrity, and also crimp cap quality. A sufficiently high force to remove the flip-off button prior to usage is required to ensure quality of the drug product unit by the flip-off button during storage, transportation, and until opening and use. Therefore, the final product is 100% visually inspected for lose or defective crimp caps, which is subjective as well as time- and labor-intensive. In this study, we sealed several container closure system configurations with different capping equipment settings (with corresponding residual seal force values) to investigate the torque moment required to turn the crimp cap. A correlation between torque moment and residual seal force has been established. The torque moment was found to be influenced by several parameters, including diameter of the vial head, type of rubber stopper (serum or lyophilized) and type of crimp cap (West(®) or Datwyler(®)). In addition, we measured the force required to remove the flip-off button of a sealed container closure system. The capping process had no influence on measured forces; however, it was possible to detect partially crimped vials. In conclusion, a controlled capping process with a defined target residual seal force range leads to a tight crimp cap on a sealed container closure system and can ensure product quality. The majority of parenteral drug products are manufactured in a glass vials with an elastomeric rubber stopper and a crimp cap. The vial sealing process is a critical process step during fill-and-finish operations, as it defines the seal quality of the final product. An adequate force to remove the flip-off button prior to usage is required to ensure product quality during storage and transportation until use. In addition, the complete crimp cap needs to be fixed in a tight position on the vial. In this study, we investigated the torque moment required to turn the crimp cap and the force required to remove the flip-off button of container closure system sealed with different capping equipment process parameters (having different residual seal force values). © PDA, Inc. 2016.

Application of small panel damping measurements to larger walls

NASA Astrophysics Data System (ADS)

Hastings, Mardi C.; Godfrey, Richard; Babcock, G. Madison

1996-05-01

Damping properties of a viscoelastic material were determined using a standard resonant beam technique. The damping material was then applied to 1 by 2 foot gypsum panels in a constrained layer construction. Damping loss factors in panels with and without the constrained layer were determined based on reverberation times after excitation at third-octave band center frequencies. The constrained damping layer had been designed to increase damping by an order of magnitude above that of a single gypsum panel at 2000 Hz; however, relative to a gypsum panel of the same overall thickness as the panel with the constrained layer, loss factors increased only by a factor of three to five. Next modal damping loss factors in 9 by 14 foot gypsum single and double walls were calculated from the experimentally determined quality factor for each modal resonance. Results showed that below 2500 Hz, modes in 1 by 2 foot gypsum panels had nearly the same damping loss factors as modes in a 9 by 14 foot gypsum wall of the same thickness; however, loss factors for the wall were an order of magnitude lower than those of the 1 by 2 foot panels at frequencies above 2500 Hz, the coincidence frequency for 5/8-inch thick gypsum plates. Thus it was inconclusive whether or not damping loss factors measured using small panels could be used to estimate the effect of a constrained damping layer on transmission loss through a 9 by 14 foot wall unless boundary conditions and modal frequencies were the same for each size.

Are assessments of damping capacity and placement torque useful in estimating root proximity of orthodontic anchor screws?

PubMed

Motoyoshi, Mitsuru; Uchida, Yasuki; Inaba, Mizuki; Ejima, Ken-Ichiro; Honda, Kazuya; Shimizu, Noriyoshi

2016-07-01

Placement torque and damping capacity may increase when the orthodontic anchor screws make contact with an adjacent root. If this is the case, root contact can be inferred from the placement torque and damping capacity. The purpose of this study was to verify the detectability of root proximity of the screws by placement torque and damping capacity. For this purpose, we investigated the relationship among placement torque, damping capacity, and screw-root proximity. The placement torque, damping capacity, and root proximity of 202 screws (diameter, 1.6 mm; length, 8.0 mm) were evaluated in 110 patients (31 male, 79 female; mean age, 21.3 ± 6.9 years). Placement torque was measured using a digital torque tester, damping capacity was measured with a Periotest device (Medizintechnik Gulden, Modautal, Germany), and root contact was judged using cone-beam computed tomography images. The rate of root contact was 18.3%. Placement torque and damping capacity were 7.8 N·cm and 3.8, respectively. The placement torque of screws with root contact was greater than that of screws with no root contact (P <0.05; effect size, 0.44; power, <0.8). Damping capacity of screws with root contact was significantly greater than that of screws with no root contact (P <0.01; effect size, >0.5; power, >0.95). It was suggested that the damping capacity is related to root contact. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Translational damping on high-frequency flapping wings

NASA Astrophysics Data System (ADS)

Parks, Perry A.

Flapping fliers such as insects and birds depend on passive translational and rotational damping to terminate quick maneuvers and to provide a source of partial stability in an otherwise unstable dynamic system. Additionally, passive translational and rotational damping reduce the amount of active kinematic changes that must be made to terminate maneuvers and maintain stability. The study of flapping-induced damping phenomena also improves the understanding of micro air vehicle (MAV) dynamics needed for the synthesis of effective flight control strategies. Aerodynamic processes which create passive translational and rotational damping as a direct result of symmetric flapping with no active changes in wing kinematics have been previously studied and were termed flapping counter-force (FCF) and flapping counter-torque (FCT), respectively. In this first study of FCF measurement in air, FCF generation is measured using a pendulum system designed to isolate and measure the relationship of translational flapping-induced damping with wingbeat frequency for a 2.86 gram mechanical flapper equipped with real cicada wings. Analysis reveals that FCF generation and wingbeat frequency are directly proportional, as expected from previous work. The quasi-steady FCF model using Blade-Element-Theory is used as an estimate for translational flapping-induced damping. In most cases, the model proves to be accurate in predicting the relationship between flapping-induced damping and wingbeat frequency. "Forward-backward" motion proves to have the strongest flapping-induced damping while "up-down" motion has the weakest.

High damping Al-Fe-Mo-Si/Zn-Al composites produced by rapidly solidified powder metallurgy process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, P.Y.; Dai, S.L.; Chai, S.C.

2000-05-10

The metallic materials commonly used in aircraft and aerospace fields, such as aluminum and titanium alloys, steels, etc., show extremely low damping capacity (usually of the order of or less than 10{sup {minus}3}). Thus, some problems related to vibration may emerge and influence the reliability, safety and life of airplanes, satellites, etc. It has been reported that almost two thirds of errors for rockets and satellites are related to vibration and noise. One effective way to solve these vibration-related problems is to adopt high damping metallic materials. Conventional high damping alloys exhibit damping capacity above 10{sup {minus}2}, however, their densitiesmore » are usually great than 5 x 10{sup 3} kg m{sup {minus}3}, or their strengths are less than 200 MPa (for alloys based on dislocation damping), making them impossible to be applied to aircraft and aerospace areas. Recently, some low-density high-damping metal/metal composites based on aluminum and high damping alloys have been developed in Beijing Institute of Aeronautical Materials (BIAM) by the rapidly solidified power metallurgy process. This paper aims to report the properties of the composites based on a high temperature Al-Fe-Mo-Si alloy and a high damping Zn-Al alloy, and compare them with that of 2618-T61 alloy produced by the ingot metallurgy process.« less

Relation of squeezed states between damped harmonic and simple harmonic oscillators

NASA Technical Reports Server (NTRS)

Um, Chung-In; Yeon, Kyu-Hwang; George, Thomas F.; Pandey, Lakshmi N.

1993-01-01

The minimum uncertainty and other relations are evaluated in the framework of the coherent states of the damped harmonic oscillator. It is shown that the coherent states of the damped harmonic oscillator are the squeezed coherent states of the simple harmonic oscillator. The unitary operator is also constructed, and this connects coherent states with damped harmonic and simple harmonic oscillators.

Collisionless Electrostatic Shock Modeling and Simulation

DTIC Science & Technology

2016-10-21

unlimited. PA#16490 Dissipation Controls Wave Train Under- and Over-damped Shocks – Under-damped: • Dissipation is weak, ripples persist. • High...Density Position – Over-damped: ● Strong dissipation damps ripples . ● Low Density Position 12 Position Distribution A. Approved for public release...distribution unlimited. PA#16490 Model Verification Comparison with Linearized Solution – Evolution of the First Ripple Wavelength: • Simulated

Characterization of hydrofoil damping due to fluid-structure interaction using piezocomposite actuators

NASA Astrophysics Data System (ADS)

Seeley, Charles; Coutu, André; Monette, Christine; Nennemann, Bernd; Marmont, Hugues

2012-03-01

Hydroelectric power generation is an important non-fossil fuel power source to help meet the world’s energy needs. Fluid-structure interaction (FSI), in the form of mass loading and damping, governs the dynamic response of water turbines, such as Francis turbines. Although the effects of fluid mass loading are well documented, fluid damping is also a critical quantity that may limit vibration amplitudes during service, and therefore help to avoid premature failure of the turbines. However, fluid damping has received less attention in the literature. This paper presents an experimental investigation of damping due to FSI. Three hydrofoils were designed and built to investigate damping due to FSI. Piezoelectric actuation using macrofiber composites (MFCs) provided excitation to the hydrofoil test structure, independent of the flow conditions, to overcome the noisy environment. Natural frequency and damping estimates were experimentally obtained from sine sweep frequency response functions measured with a laser vibrometer through a window in the test section. The results indicate that, although the natural frequencies were not substantially affected by the flow, the damping ratios were observed to increase in a linear manner with respect to flow velocity.

Cellular Magnesium Matrix Foam Composites for Mechanical Damping Applications

NASA Astrophysics Data System (ADS)

Shunmugasamy, Vasanth Chakravarthy; Mansoor, Bilal; Gupta, Nikhil

2016-01-01

The damping characteristics of metal alloys and metal matrix composites are relevant to the automotive, aerospace, and marine structures. Use of lightweight materials can help in increasing payload capacity and in decreasing fuel consumption. Lightweight composite materials possessing high damping capabilities that can be designed as structural members can greatly benefit in addressing these needs. In this context, the damping properties of lightweight metals such as aluminum and magnesium and their respective composites have been studied in the existing literature. This review focuses on analyzing the damping properties of aluminum and magnesium alloys and their cellular composites. The damping properties of various lightweight alloys and composites are compared on the basis of their density to understand the potential for weight saving in structural applications. Magnesium alloys are observed to possess better damping properties in comparison to aluminum. However, aluminum matrix syntactic foams reinforced with silicon carbide hollow particles possess a damping capacity and density comparable to magnesium alloy. By using the data presented in the study, composites with specific compositions and properties can be selected for a given application. In addition, the comparison of the results helps in identifying the areas where attention needs to be focused to address the future needs.

Viscous-to-viscoelastic transition in phononic crystal and metamaterial band structures.

PubMed

Frazier, Michael J; Hussein, Mahmoud I

2015-11-01

The dispersive behavior of phononic crystals and locally resonant metamaterials is influenced by the type and degree of damping in the unit cell. Dissipation arising from viscoelastic damping is influenced by the past history of motion because the elastic component of the damping mechanism adds a storage capacity. Following a state-space framework, a Bloch eigenvalue problem incorporating general viscoelastic damping based on the Zener model is constructed. In this approach, the conventional Kelvin-Voigt viscous-damping model is recovered as a special case. In a continuous fashion, the influence of the elastic component of the damping mechanism on the band structure of both a phononic crystal and a metamaterial is examined. While viscous damping generally narrows a band gap, the hereditary nature of the viscoelastic conditions reverses this behavior. In the limit of vanishing heredity, the transition between the two regimes is analyzed. The presented theory also allows increases in modal dissipation enhancement (metadamping) to be quantified as the type of damping transitions from viscoelastic to viscous. In conclusion, it is shown that engineering the dissipation allows one to control the dispersion (large versus small band gaps) and, conversely, engineering the dispersion affects the degree of dissipation (high or low metadamping).

A modified precise integration method for transient dynamic analysis in structural systems with multiple damping models

NASA Astrophysics Data System (ADS)

Ding, Zhe; Li, Li; Hu, Yujin

2018-01-01

Sophisticated engineering systems are usually assembled by subcomponents with significantly different levels of energy dissipation. Therefore, these damping systems often contain multiple damping models and lead to great difficulties in analyzing. This paper aims at developing a time integration method for structural systems with multiple damping models. The dynamical system is first represented by a generally damped model. Based on this, a new extended state-space method for the damped system is derived. A modified precise integration method with Gauss-Legendre quadrature is then proposed. The numerical stability and accuracy of the proposed integration method are discussed in detail. It is verified that the method is conditionally stable and has inherent algorithmic damping, period error and amplitude decay. Numerical examples are provided to assess the performance of the proposed method compared with other methods. It is demonstrated that the method is more accurate than other methods with rather good efficiency and the stable condition is easy to be satisfied in practice.

Emergence of anisotropic Gilbert damping in ultrathin Fe layers on GaAs(001)

NASA Astrophysics Data System (ADS)

Chen, L.; Mankovsky, S.; Wimmer, S.; Schoen, M. A. W.; Körner, H. S.; Kronseder, M.; Schuh, D.; Bougeard, D.; Ebert, H.; Weiss, D.; Back, C. H.

2018-05-01

As a fundamental parameter in magnetism, the phenomenological Gilbert damping constant α determines the performance of many spintronic devices. For most magnetic materials, α is treated as an isotropic parameter entering the Landau-Lifshitz-Gilbert equation. However, could the Gilbert damping be anisotropic? Although several theoretical approaches have suggested that anisotropic α could appear in single-crystalline bulk systems, experimental evidence of its existence is scarce. Here, we report the emergence of anisotropic magnetic damping by exploring a quasi-two-dimensional single-crystalline ferromagnetic metal/semiconductor interface—that is, a Fe/GaAs(001) heterojunction. The observed anisotropic damping shows twofold C2v symmetry, which is expected from the interplay of interfacial Rashba and Dresselhaus spin-orbit interaction, and is manifested by the anisotropic density of states at the Fe/GaAs (001) interface. This discovery of anisotropic damping will enrich the understanding of magnetization relaxation mechanisms and can provide a route towards the search for anisotropic damping at other ferromagnetic metal/semiconductor interfaces.

Reliable Channel-Adapted Error Correction: Bacon-Shor Code Recovery from Amplitude Damping

NASA Astrophysics Data System (ADS)

Piedrafita, Álvaro; Renes, Joseph M.

2017-12-01

We construct two simple error correction schemes adapted to amplitude damping noise for Bacon-Shor codes and investigate their prospects for fault-tolerant implementation. Both consist solely of Clifford gates and require far fewer qubits, relative to the standard method, to achieve exact correction to a desired order in the damping rate. The first, employing one-bit teleportation and single-qubit measurements, needs only one-fourth as many physical qubits, while the second, using just stabilizer measurements and Pauli corrections, needs only half. The improvements stem from the fact that damping events need only be detected, not corrected, and that effective phase errors arising due to undamped qubits occur at a lower rate than damping errors. For error correction that is itself subject to damping noise, we show that existing fault-tolerance methods can be employed for the latter scheme, while the former can be made to avoid potential catastrophic errors and can easily cope with damping faults in ancilla qubits.

Ultralow Damping in Nanometer-Thick Epitaxial Spinel Ferrite Thin Films.

PubMed

Emori, Satoru; Yi, Di; Crossley, Sam; Wisser, Jacob J; Balakrishnan, Purnima P; Khodadadi, Behrouz; Shafer, Padraic; Klewe, Christoph; N'Diaye, Alpha T; Urwin, Brittany T; Mahalingam, Krishnamurthy; Howe, Brandon M; Hwang, Harold Y; Arenholz, Elke; Suzuki, Yuri

2018-06-08

Pure spin currents, unaccompanied by dissipative charge flow, are essential for realizing energy-efficient nanomagnetic information and communications devices. Thin-film magnetic insulators have been identified as promising materials for spin-current technology because they are thought to exhibit lower damping compared with their metallic counterparts. However, insulating behavior is not a sufficient requirement for low damping, as evidenced by the very limited options for low-damping insulators. Here, we demonstrate a new class of nanometer-thick ultralow-damping insulating thin films based on design criteria that minimize orbital angular momentum and structural disorder. Specifically, we show ultralow damping in <20 nm thick spinel-structure magnesium aluminum ferrite (MAFO), in which magnetization arises from Fe 3+ ions with zero orbital angular momentum. These epitaxial MAFO thin films exhibit a Gilbert damping parameter of ∼0.0015 and negligible inhomogeneous linewidth broadening, resulting in narrow half width at half-maximum linewidths of ∼0.6 mT around 10 GHz. Our findings offer an attractive thin-film platform for enabling integrated insulating spintronics.

Metallic ferromagnetic films with magnetic damping under 1.4 × 10 -3

DOE PAGES

Lee, Aidan J.; Brangham, Jack T.; Cheng, Yang; ...

2017-08-10

Low-damping magnetic materials have been widely used in microwave and spintronic applications because of their low energy loss and high sensitivity. While the Gilbert damping constant can reach 10 -4 to 10 -5 in some insulating ferromagnets, metallic ferromagnets generally have larger damping due to magnon scattering by conduction electrons. Meanwhile, low-damping metallic ferromagnets are desired for charge-based spintronic devices. In this article, we report the growth of Co 25Fe 75 epitaxial films with excellent crystalline quality evident by the clear Laue oscillations and exceptionally narrow rocking curve in the X-ray diffraction scans as well as from scanning transmission electronmore » microscopy. Remarkably, the Co 25Fe 75 epitaxial films exhibit a damping constant <1.4 × 10 -3, which is comparable to the values for some high-quality Y 3Fe 5O 12 films. This record low damping for metallic ferromagnets offers new opportunities for charge-based applications such as spin-transfer-torque-induced switching and magnetic oscillations.« less

Damping characterization in large structures

NASA Technical Reports Server (NTRS)

Eke, Fidelis O.; Eke, Estelle M.

1991-01-01

This research project has as its main goal the development of methods for selecting the damping characteristics of components of a large structure or multibody system, in such a way as to produce some desired system damping characteristics. The main need for such an analytical device is in the simulation of the dynamics of multibody systems consisting, at least partially, of flexible components. The reason for this need is that all existing simulation codes for multibody systems require component-by-component characterization of complex systems, whereas requirements (including damping) often appear at the overall system level. The main goal was met in large part by the development of a method that will in fact synthesize component damping matrices from a given system damping matrix. The restrictions to the method are that the desired system damping matrix must be diagonal (which is almost always the case) and that interbody connections must be by simple hinges. In addition to the technical outcome, this project contributed positively to the educational and research infrastructure of Tuskegee University - a Historically Black Institution.

A novel sandwich Fe-Mn damping alloy with ferrite shell prepared by vacuum annealing

NASA Astrophysics Data System (ADS)

Qian, Bingnan; Peng, Huabei; Wen, Yuhua

2018-04-01

To improve the corrosion resistance of high strength Fe-Mn damping alloys, we fabricated a novel sandwich Fe-17.5Mn damping alloy with Mn-depleted ferrite shell by vacuum annealing at 1100 °C. The formation behavior of the ferrite shell obeys the parabolic law for the vacuum annealed Fe-17.5Mn alloy at 1100 °C. The sandwich Fe-17.5Mn alloy with ferrite shell exhibits not only better corrosion resistance but also higher damping capacity than the conventional annealed Fe-17.5Mn alloy under argon atmosphere. The existence of only ferrite shell on the surface accounts for the better corrosion in the sandwich Fe-17.5Mn alloy. The better damping capacity in the sandwich Fe-17.5Mn alloy is owed to more stacking faults inside both ɛ martensite and γ austenite induced by the stress from ferrite shell. Vacuum annealing is a new way to improve the corrosion resistance and damping capacity of Fe-Mn damping alloys.

Nonlinear damping model for flexible structures. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Zang, Weijian

1990-01-01

The study of nonlinear damping problem of flexible structures is addressed. Both passive and active damping, both finite dimensional and infinite dimensional models are studied. In the first part, the spectral density and the correlation function of a single DOF nonlinear damping model is investigated. A formula for the spectral density is established with O(Gamma(sub 2)) accuracy based upon Fokker-Planck technique and perturbation. The spectral density depends upon certain first order statistics which could be obtained if the stationary density is known. A method is proposed to find the approximate stationary density explicitly. In the second part, the spectral density of a multi-DOF nonlinear damping model is investigated. In the third part, energy type nonlinear damping model in an infinite dimensional setting is studied.

Passively Damped Laminated Piezoelectric Shell Structures with Integrated Electric Networks

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1999-01-01

Multi-field mechanics are presented for curvilinear piezoelectric laminates interfaced with distributed passive electric components. The equations of motion for laminated piezoelectric shell structures with embedded passive electric networks are directly formulated and solved using a finite element methodology. The modal damping and frequencies of the piezoelectric shell are calculated from the poles of the system. Experimental and numerical results are presented for the modal damping and frequency of composite beams with a resistively shunted piezoceramic patch. The modal damping and frequency of plates, cylindrical shells and cylindrical composite blades with piezoelectric-resistor layers are predicted. Both analytical and experimental studies illustrate a unique dependence of modal damping and frequencies on the shunting resistance and show the effect of structural shape and curvature on piezoelectric damping.

Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.; Provenza, Andrew J.; Trudell, Jeffrey J.; Min, James B.

2009-01-01

Researchers at NASA Glenn Research Center have been investigating shunted piezoelectric circuits as potential damping treatments for turbomachinery rotor blades. This effort seeks to determine the effects of centrifugal loading on passively-shunted piezoelectric - damped plates. Passive shunt circuit parameters are optimized for the plate's third bending mode. Tests are performed both non-spinning and in the Dynamic Spin Facility to verify the analysis, and to determine the effectiveness of the damping under centrifugal loading. Results show that a resistive shunt circuit will reduce resonant vibration for this configuration. However, a tuned shunt circuit will be required to achieve the desired damping level. The analysis and testing address several issues with passive shunt circuit implementation in a rotating system, including piezoelectric material integrity under centrifugal loading, shunt circuit implementation, and tip mode damping.

The Characteristics of Vibration Isolation System with Damping and Stiffness Geometrically Nonlinear

NASA Astrophysics Data System (ADS)

Lu, Ze-Qi; Chen, Li-Qun; Brennan, Michael J.; Li, Jue-Ming; Ding, Hu

2016-09-01

The paper concerns an investigation into the use of both stiffness and damping nonlinearity in the vibration isolator to improve its effectiveness. The nonlinear damping and nonlinear stiffness are both achieved by horizontal damping and stiffness as the way of the geometrical nonlinearity. The harmonic balance method is used to analyze the force transmissibility of such vibration isolation system. It is found that as the horizontal damping increasing, the height of the force transmissibility peak is decreased and the high-frequency force transmissibility is almost the same. The results are also validated by some numerical method. Then the RMS of transmissibility under Gaussian white noise is calculated numerically, the results demonstrate that the beneficial effects of the damping nonlinearity can be achieved under random excitation.

Cell Death and DAMPs in Acute Pancreatitis

PubMed Central

Kang, Rui; Lotze, Michael T; Zeh, Herbert J; Billiar, Timothy R; Tang, Daolin

2014-01-01

Cell death and inflammation are key pathologic responses of acute pancreatitis (AP), the leading cause of hospital admissions for gastrointestinal disorders. It is becoming increasingly clear that damage-associated molecular pattern molecules (DAMPs) play an important role in the pathogenesis of AP by linking local tissue damage to systemic inflammation syndrome. Endogenous DAMPs released from dead, dying or injured cells initiate and extend sterile inflammation via specific pattern recognition receptors. Inhibition of the release and activity of DAMPs (for example, high mobility group box 1, DNA, histones and adenosine triphosphate) provides significant protection against experimental AP. Moreover, increased serum levels of DAMPs in patients with AP correlate with disease severity. These findings provide novel insight into the mechanism, diagnosis and management of AP. DAMPs might be an attractive therapeutic target in AP. PMID:25105302

Damping characteristics of damaged fiber composite components

NASA Technical Reports Server (NTRS)

Eberle, K.

1986-01-01

Defects in fiber composite components produce changes with respect to the vibrational characteristics of the material. These changes can be recognized in the form of a frequency shift or an alteration of the damping process. The present investigation is concerned with questions regarding the possibility of a utilization of the changes in suitable defect-detecting inspection procedures. A description is given of a method for measuring the damping characteristics of a specimen. This method provides a spectrum of the damping coefficients of the sample as a basis for a comprehensive evaluation of the damping behavior. The correlation between defects and change in the damping characteristics is demonstrated with the aid of results obtained in measurements involving specimens of carbon-fiber composites and a component consisting of glass-fiber-reinforced plastics.

Riot Control Agents

MedlinePlus

... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir What riot control agents are Riot control agents (sometimes referred to ...

Nobody Reads Billboards!

ERIC Educational Resources Information Center

Walker, Joseph J.; Lotz, Condit

1982-01-01

The authors describe an incidental learning approach using supplementary reading sources such as bumper stickers, t-shirts, and novelty buttons to encourage gifted students' analysis and synthesis skills. (CL)

On force-deflection diagrams of airplane shock absorber struts : first, second, and third partial reports

NASA Technical Reports Server (NTRS)

Schlaefke, Karlhans

1954-01-01

This paper, which is presented in three parts, is an analytical study of the behavior of landing gear shock struts, with various types of assumptions for the shock-strut characteristics. The effects of tire springing are neglected. The first part compares the behavior of struts with linear and quadratic damping. The second part considers struts with nonlinear spring characteristics and linear or quadratic damping. The third part treats the oleo-pneumatic strut with air-compression springing without damping and with damping proportional to velocity. It is indicated how the damping factor can be determined by experiment.

Damping mechanisms in chemically vapor deposited SiC fibers

NASA Technical Reports Server (NTRS)

Dicarlo, James A.; Goldsby, Jon C.

1993-01-01

Evaluating the damping of reinforcement fibers is important for understanding their microstructures and the vibrational response of their structural composites. In this study the damping capacities of two types of chemically vapor deposited silicon carbide fibers were measured from -200 C to as high as 800 C. Measurements were made at frequencies in the range 50 to 15000 Hz on single cantilevered fibers. At least four sources were identified which contribute to fiber damping, the most significant being thermoelastic damping and grain boundary sliding. The mechanisms controlling all sources and their potential influence on fiber and composite performance are discussed.

Significance of modeling internal damping in the control of structures

NASA Technical Reports Server (NTRS)

Banks, H. T.; Inman, D. J.

1992-01-01

Several simple systems are examined to illustrate the importance of the estimation of damping parameters in closed-loop system performance and stability. The negative effects of unmodeled damping are particularly pronounced in systems that do not use collocated sensors and actuators. An example is considered for which even the actuators (a tip jet nozzle and flexible hose) for a simple beam produce significant damping which, if ignored, results in a model that cannot yield a reasonable time response using physically meaningful parameter values. It is concluded that correct damping modeling is essential in structure control.

Investigation of Damping Physics and CFD Tool Validation for Simulation of Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeffrey

2016-01-01

To meet the flight control damping requirement, baffles of various configurations have been devised to increase the natural viscous damping and decrease the magnitude of the slosh forces and torques. In the design of slosh baffles, the most widely used damping equation is the one derived by Miles, which is based on the experiments of Keulegan and Carpenter. This equation has been used in predicting damping of the baffled tanks in different diameters ranging from 12 to 112 inches. The analytical expression of Miles equation is easy to use, especially in the design of complex baffle system. Previous investigations revealed that some experiments had shown good agreements with the prediction method of Miles, whereas other experiments have shown significant deviations. For example, damping from Miles equation differs from experimental measurements by as much as 100 percent over a range of tank diameters from 12 to 112 inches, oscillation amplitudes from 0.1 to 1.5 baffle widths, and baffle depths of 0.3 to 0.5 tank radius. Previously, much of this difference has been attributed to experimental scatter. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between Miles equation and experimental measurement, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use CFD technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. A well validated CFD solver, developed at NASA MSFC, Loci-STREAM-VOF, is applied to study vorticity field around the baffle and around the fluid interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data are then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (h/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

TECHNICAL NOTE: Direct finite-element analysis of the frequency response of a Y-Z lithium niobate SAW filter

NASA Astrophysics Data System (ADS)

Xu, Guanshui

2000-12-01

A direct finite-element model is developed for the full-scale analysis of the electromechanical phenomena involved in surface acoustic wave (SAW) devices. The equations of wave propagation in piezoelectric materials are discretized using the Galerkin method, in which an implicit algorithm of the Newmark family with unconditional stability is implemented. The Rayleigh damping coefficients are included in the elements near the boundary to reduce the influence of the reflection of waves. The performance of the model is demonstrated by the analysis of the frequency response of a Y-Z lithium niobate filter with two uniform ports, with emphasis on the influence of the number of electrodes. The frequency response of the filter is obtained through the Fourier transform of the impulse response, which is solved directly from the finite-element simulation. It shows that the finite-element results are in good agreement with the characteristic frequency response of the filter predicted by the simple phase-matching argument. The ability of the method to evaluate the influence of the bulk waves at the high-frequency end of the filter passband and the influence of the number of electrodes on insertion loss is noteworthy. We conclude that the direct finite-element analysis of SAW devices can be used as an effective tool for the design of high-performance SAW devices. Some practical computational challenges of finite-element modeling of SAW devices are discussed.

Enhanced annealing stability and perpendicular magnetic anisotropy in perpendicular magnetic tunnel junctions using W layer

NASA Astrophysics Data System (ADS)

Chatterjee, Jyotirmoy; Sousa, Ricardo C.; Perrissin, Nicolas; Auffret, Stéphane; Ducruet, Clarisse; Dieny, Bernard

2017-05-01

The magnetic properties of the perpendicular storage electrode (buffer/MgO/FeCoB/Cap) were studied as a function of annealing temperature by replacing Ta with W and W/Ta cap layers with variable thicknesses. W in the cap boosts up the annealing stability and increases the effective perpendicular anisotropy by 30% compared to the Ta cap. Correspondingly, an increase in the FeCoB critical thickness characterizing the transition from perpendicular to in-plane anisotropy was observed. Thicker W layer in the W(t)/Ta 1 nm cap layer makes the storage electrode highly robust against annealing up to 570 °C. The stiffening of the overall stack resulting from the W insertion due to its very high melting temperature seems to be the key mechanism behind the extremely high thermal robustness. The Gilbert damping constant of FeCoB with the W/Ta cap was found to be lower when compared with the Ta cap and stable with annealing. The evolution of the magnetic properties of bottom pinned perpendicular magnetic tunnel junctions (p-MTJ) stack with the W2/Ta1 nm cap layer shows back-end-of-line compatibility with increasing tunnel magnetoresistance up to the annealing temperature of 425 °C. The pMTJ thermal budget is limited by the synthetic antiferromagnetic hard layer which is stable up to 425 °C annealing temperature while the storage layer is stable up to 455 °C.

Uniform stabilization of wave equation with localized internal damping and acoustic boundary condition with viscoelastic damping

NASA Astrophysics Data System (ADS)

Frota, Cícero Lopes; Vicente, André

2018-06-01

In this paper, we deal with the uniform stabilization to the mixed problem for a nonlinear wave equation and acoustic boundary conditions on a non-locally reacting boundary. The main purpose is to study the stability when the internal damping acts only over a subset ω of the domain Ω and the boundary damping is of the viscoelastic type.

MISSILE DATCOM User’s Manual - 2011 Revision

DTIC Science & Technology

2011-03-01

out. This control card is effective only for the case in which it appears. The following data will be computed and output: Table 24. Magnus ...SOSE, SUPBOD Dynamic derivatives BDAMP, DAMP2 BDAMP, DAMP2 Magnus derivatives SPIN83, DAMP2 SPIN83, DAMP2 Plume effects BOTCNM, BOTCA, BASPRS... Magnus derivatives calculated with SPIN Control Card .................................................. 59 Table 25. Dictionary listing for the FOR020

Collisional damping of the geodesic acoustic mode with toroidal rotation. I. Viscous damping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, Xueyu; Xie, Baoyi; Chen, You

2016-03-15

With the dispersion relation derived for the geodesic acoustic mode in toroidally rotating tokamak plasmas using the fluid model, the effect of the toroidal rotation on the collisional viscous damping of the geodesic acoustic mode is investigated. It is found that the collisional viscous damping of the geodesic acoustic mode has weak increase with respect to the toroidal Mach number.

Passive and Active Control of Space Structures (PACOSS)

NASA Astrophysics Data System (ADS)

Morosow, G.; Harcrow, H.; Rogers, L.

1985-04-01

Passive and Active Control of Space Structures (PACOSS) is a five-year program designed to investigate highly damped structures in conjunction with active control systems, and in particular to develop technology that integrates passive damping and active control to achieve precise pointing control. Major areas of research include metal matrix composites; viscoelastic materials; damping devices; dynamic test article design, fabrication and testing; and active damping.

Conversation Effects on Neural Mechanisms Underlying Reaction Time to Visual Events while Viewing a Driving Scene using MEG

PubMed Central

Bowyer, Susan M.; Hsieh, Li; Moran, John E.; Young, Richard A.; Manoharan, Arun; Liao, Chia-cheng Jason; Malladi, Kiran; Yu, Ya-Ju; Chiang, Yow-Ren; Tepley, Norman

2009-01-01

Magnetoencephalography (MEG) imaging examined the neural mechanisms that modulate reaction times to visual events while viewing a driving video, with and without a conversation. Twenty-four subjects ages 18–65 were monitored by whole-head MEG. The primary tasks were to monitor a driving video and to depress a foot pedal in response to a small red light presented to the left or below the driving scene at unpredictable times. The behavioral reaction time (RT) to the lights was recorded. The secondary task was a hands-free conversation. The subject pressed a button to answer a ring tone, and then covertly answered pre-recorded non-emotional questions such as “What is your birth date?” RTs for the conversation task (1043ms, SE=65ms) were slightly longer than for the primary task (baseline no conversation (944ms, SE=48ms). During the primary task RTs were inversely related to the amount of brain activity detected by MEG in the right superior parietal lobe (Brodmann’s Area 7). Brain activity was seen in the 200 to 300 ms range after the onset of the red light and in the visual cortex (BA 19) about 85 ms after the red light. Conversation reduced the strengths of these regression relationships and increased mean RT. Conversation may contribute to increased reaction times by (1) damping brain activation in specific regions during specific time windows, or (2) reducing facilitation from attention inputs into those areas. These laboratory findings should not be interpreted as indicative of real-world driving, without on-road validation, and comparison to other in-vehicle tasks. PMID:18992728

The ROSETTA PHILAE Lander damping mechanism as probe for the Comet soil strength.

NASA Astrophysics Data System (ADS)

Roll, R.

2015-10-01

The ROSETTA Lander is equipped with an one axis damping mechanism to dissipate kinetic energy during the touch down. This damping is necessary to avoid damages to the Lander by a hard landing shock and more important to avoid re-bouncing from ground with high velocity. The damping mechanism works best for perpendicular impact, which means the velocity vector is parallel to the damper axis and all three feet touch the ground at the same time. That is usually not the case. Part of the impact energy can be transferred into rotational energy at ground contact if the impact is not perpendicular. This energy will lift up the Lander from the ground if the harpoons and the hold down thruster fail, as happen in mission. The damping mechanism itself is an electrical generator, driven by a spindle inside a telescopic tube. This tube was extended in mission for landing by 200mm. A maximum damping length of 140mm would be usually required to compensate a landing velocity of 1m/s, if the impact happens perpendicular on hard ground. After landing the potentiometer of the telescopic tube reading shows a total damping length of only 42,5mm. The damping mechanism and the overall mechanical behavior of the Lander at touch down are well tested and characterized and transferred to a multi-body computer model. The incoming and outgoing flightpath of PHILAE allow via computer-simulation the reconstruction of the touch down. It turns out, that the outgoing flight direction is dominated by the local ground slope and that the damping length is strongly dependent on the soil strength. Damping of soft comet ground must be included to fit the damping length measured. Scenario variations of the various feet contact with different local surface features (stone or regolith) and of different soil models finally lead to a restricted range for the soil strength at the touch down area.

Coronal loop seismology using damping of standing kink oscillations by mode coupling

NASA Astrophysics Data System (ADS)

Pascoe, D. J.; Goddard, C. R.; Nisticò, G.; Anfinogentov, S.; Nakariakov, V. M.

2016-05-01

Context. Kink oscillations of solar coronal loops are frequently observed to be strongly damped. The damping can be explained by mode coupling on the condition that loops have a finite inhomogeneous layer between the higher density core and lower density background. The damping rate depends on the loop density contrast ratio and inhomogeneous layer width. Aims: The theoretical description for mode coupling of kink waves has been extended to include the initial Gaussian damping regime in addition to the exponential asymptotic state. Observation of these damping regimes would provide information about the structuring of the coronal loop and so provide a seismological tool. Methods: We consider three examples of standing kink oscillations observed by the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) for which the general damping profile (Gaussian and exponential regimes) can be fitted. Determining the Gaussian and exponential damping times allows us to perform seismological inversions for the loop density contrast ratio and the inhomogeneous layer width normalised to the loop radius. The layer width and loop minor radius are found separately by comparing the observed loop intensity profile with forward modelling based on our seismological results. Results: The seismological method which allows the density contrast ratio and inhomogeneous layer width to be simultaneously determined from the kink mode damping profile has been applied to observational data for the first time. This allows the internal and external Alfvén speeds to be calculated, and estimates for the magnetic field strength can be dramatically improved using the given plasma density. Conclusions: The kink mode damping rate can be used as a powerful diagnostic tool to determine the coronal loop density profile. This information can be used for further calculations such as the magnetic field strength or phase mixing rate.

[Damping inserts have no load reducing effect in the fatigued state].

PubMed

Melnyk, M; Gollhofer, A

2008-09-01

Overload injuries to the lower limbs may be attributed to repetitive, non-physiological load stimuli. However, these impact loads acting on the musculoskeletal can be reduced by wearing damping inserts. To date, however, there is only little evidence as to whether this positive effect can be assigned to the damping insert and, furthermore, whether this effect is detectable in states of muscle fatigue. Therefore, the influence of muscle fatigue in combination with the wearing of damping inserts was investigated in 13 subjects. The parameters examined in this study were ground reaction forces during walking and the muscular activation profile of the lower limb in the phase of initial ground contact. The results showed that neither in comparisons with and without damping inserts nor in states of muscular fatigue could significant differences were found in the ground reaction forces. Wereas, no significant differences could be detected in the investigated muscles, with and without damping inserts, preactivation in the peroneal and biceps femoris muscles were significantly earlier, in states of muscular fatigue with damping inserts, while no changes could be found in the anterior tibial, soleus, vastus lateralis and gastrocnemius muscles. The present results demonstrate that wearing damping inserts does not lead to a positive effect with regard to a reduction of the ground reaction forces. The earlier preactivation in the case of muscle fatigue with a damping insert is indicative of an increased energy expenditure which may be possibly associated with increased knee and ankle joint control. The high satisfaction concerning the comfort of wearing such inserts revealed by a questionnaire did not correlate with a reduction in loading condition. On the basis of the present results we cannot recommend the wearing of damping soft sole inserts in the context of a reduction in load condition.

Building dampness and mold in European homes in relation to climate, building characteristics and socio-economic status: The European Community Respiratory Health Survey ECRHS II.

PubMed

Norbäck, D; Zock, J-P; Plana, E; Heinrich, J; Tischer, C; Jacobsen Bertelsen, R; Sunyer, J; Künzli, N; Villani, S; Olivieri, M; Verlato, G; Soon, A; Schlünssen, V; Gunnbjörnsdottir, M I; Jarvis, D

2017-09-01

We studied dampness and mold in homes in relation to climate, building characteristics and socio-economic status (SES) across Europe, for 7127 homes in 22 centers. A subsample of 3118 homes was inspected. Multilevel analysis was applied, including age, gender, center, SES, climate, and building factors. Self-reported water damage (10%), damp spots (21%), and mold (16%) in past year were similar as observed data (19% dampness and 14% mold). Ambient temperature was associated with self-reported water damage (OR=1.63 per 10°C; 95% CI 1.02-2.63), damp spots (OR=2.95; 95% CI 1.98-4.39), and mold (OR=2.28; 95% CI 1.04-4.67). Precipitation was associated with water damage (OR=1.12 per 100 mm; 95% CI 1.02-1.23) and damp spots (OR=1.11; 95% CI 1.02-1.20). Ambient relative air humidity was not associated with indoor dampness and mold. Older buildings had more dampness and mold (P<.001). Manual workers reported less water damage (OR=0.69; 95% CI 0.53-0.89) but more mold (OR=1.27; 95% CI 1.03-1.55) as compared to managerial/professional workers. There were correlations between reported and observed data at center level (Spearman rho 0.61 for dampness and 0.73 for mold). In conclusion, high ambient temperature and precipitation and high building age can be risk factors for dampness and mold in homes in Europe. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Analysis of conductive target influence in plasma jet experiments through helium metastable and electric field measurements

NASA Astrophysics Data System (ADS)

Darny, T.; Pouvesle, J.-M.; Puech, V.; Douat, C.; Dozias, S.; Robert, Eric

2017-04-01

The use of cold atmospheric pressure plasma jets for in vivo treatments implies most of the time plasma interaction with conductive targets. The effect of conductive target contact on the discharge behavior is studied here for a grounded metallic target and compared to the free jet configuration. In this work, realized with a plasma gun, we measured helium metastable HeM (23S1) concentration (by laser absorption spectroscopy) and electric field (EF) longitudinal and radial components (by electro-optic probe). Both diagnostics were temporally and spatially resolved. Mechanisms after ionization front impact on the target surface have been identified. The remnant conductive ionized channel behind the ionization front electrically transiently connects the inner high voltage electrode to the target. Due to impedance mismatching between the ionized channel and the target, a secondary ionization front is initiated and rapidly propagates from the target surface to the inner electrode through this ionized channel. This leads to a greatly enhanced HeM production inside the plasma plume and the capillary. Forward and reverse dynamics occur with further multi reflections of more or less damped ionization fronts between the inner electrode and the target as long as the ionized channel is persisting. This phenomenon is very sensitive to parameters such as target distance and ionized channel conductivity affecting electrical coupling between these two and evidenced using positive or negative voltage polarity and nitrogen admixture. In typical operating conditions for the plasma gun used in this work, it has been found that after the secondary ionization front propagation, when the ionized channel is conductive enough, a glow like discharge occurs with strong conduction current. HeM production and all species excitation, especially reactive ones, are then driven by high voltage pulse evolution. The control of forward and reverse dynamics, impacting on the production of the glow like discharge, will be useful for biomedical applications on living tissues.

Apparatus and method of preloading vibration-damping bellows

DOEpatents

Cutburth, Ronald W.

1988-01-01

An improved vibration damping bellows mount or interconnection is disclosed. In one aspect, the bellows is compressively prestressed along its length to offset vacuum-generated tensile loads and thereby improve vibration damping characteristics.

Landau damping of the dust-acoustic surface waves in a Lorentzian dusty plasma slab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Myoung-Jae; Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr; Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590

2016-01-15

Landau damping of a dust-acoustic surface wave propagating at the interfaces of generalized Lorentzian dusty plasma slab bounded by a vacuum is kinetically derived as the surface wave displays the symmetric and the anti-symmetric mode in a plasma slab. In the limiting case of small scaled wave number, we have found that Landau damping is enhanced as the slab thickness is increased. In particular, the damping of anti-symmetric mode is much stronger for a Lorentzian plasma than for a Maxwellian plasma. We have also found that the damping is more affected by superthermal particles in a Lorentzian plasma than bymore » a Maxwellian plasma for both of the symmetric and the anti-symmetric cases. The variations of Landau damping with various parameters are also discussed.« less

Passive damping concepts for tubular beams with partial rotational and translational end restraints

NASA Technical Reports Server (NTRS)

Razzaq, Zia; Muyundo, David K.

1991-01-01

The main objectives of the study are: (1) identification of potential passive damping concepts for slender tubular structural members with rotational and translational end springs under natural and forced-free vibrations; (2) evaluation of damping efficiencies of the various damping concepts; and (3) evaluation of the suitability of a theoretical finite difference analysis by comparison to the experimental results for the case of natural vibrations. Only member flexural an translation motion is considered. The natural vibration study is conducted on the seven damping concepts and for only one specific initial deflection. The most suitable of the seven dampers is further investigated under forced-free vibrations. In addition only one set of end springs is used for all of the experiments. The results show that passive damping provides a possible approach to structural vibration reduction.

Hypersonic and transonic buzz measurements on the lower pitch flap of the M2-F2 lifting entry configuration

NASA Technical Reports Server (NTRS)

Warner, R. W.; Wilcox, P. R.

1972-01-01

Free-oscillation damping measurements at hypersonic and transonic Mach numbers are presented for the lower pitch flap of the M2-F2 reentry vehicle. For the flow and model conditions tested, the damping measurements indicate the absence of hypersonic buzz instability for flap rotation frequencies of 47.3 Hz, 153 Hz, and 360 Hz, the presence of transonic buzz for 47.3 Hz flap, and the absence of transonic buzz for a 115 Hz flap. There are not enough flap damping data for an error estimate based on repeatability, but a partial damping calibration is presented in which an analog computer simulation of random flap response for a known flap damping is fed into the autocorrelation computer and filter combination used for most of the damping measurements.

Optical rotation of levitated spheres in high vacuum

NASA Astrophysics Data System (ADS)

Monteiro, Fernando; Ghosh, Sumita; van Assendelft, Elizabeth C.; Moore, David C.

2018-05-01

A circularly polarized laser beam is used to levitate and control the rotation of microspheres in high vacuum. At low pressure, rotation frequencies as high as 6 MHz are observed for birefringent vaterite spheres, limited by centrifugal stresses. Due to the extremely low damping in high vacuum, the controlled optical rotation of amorphous SiO2 spheres is also observed at rates above several MHz. At 10-7 mbar, a damping time of 6 ×104 s is measured for a 10 -μ m -diam SiO2 sphere. No additional damping mechanisms are observed above gas damping, indicating that even longer damping times may be possible with operation at lower pressure. The controlled optical rotation of microspheres at MHz frequencies with low damping, including for materials that are not intrinsically birefringent, provides a tool for performing precision measurements using optically levitated systems.

Passive eddy-current damping as a means of vibration control in cryogenic turbomachinery

NASA Technical Reports Server (NTRS)

Cunningham, R. E.

1986-01-01

Lateral shaft vibrations produced by a rotating unbalance weight were damped by means of eddy currents generated in copper conductors that were precessing cyclicly in the gap formed by the pole faces of C-shaped, permanent magnets. The damper assembly, which was located at the lower bearing support of a vertically oriented rotor was completely immersed in liquid nitrogen during the test run. The test rotor was operated over a speed range from 800 to 10,000 rpm. Three magnet/conductor designs were evaluated. Experimental damping coefficients varied from 180 to 530 N sec/m. Reasonable agreement was noted for theoretical values of damping for these same assemblies. Values of damping coefficients varied from 150 to 780 N sec/m. The results demonstrate that passive eddy-current damping is a viable candidate for vibration control in cryogenic turbomachinery.

Evaluation of CFD Turbulent Heating Prediction Techniques and Comparison With Hypersonic Experimental Data

NASA Technical Reports Server (NTRS)

Dilley, Arthur D.; McClinton, Charles R. (Technical Monitor)

2001-01-01

Results from a study to assess the accuracy of turbulent heating and skin friction prediction techniques for hypersonic applications are presented. The study uses the original and a modified Baldwin-Lomax turbulence model with a space marching code. Grid converged turbulent predictions using the wall damping formulation (original model) and local damping formulation (modified model) are compared with experimental data for several flat plates. The wall damping and local damping results are similar for hot wall conditions, but differ significantly for cold walls, i.e., T(sub w) / T(sub t) < 0.3, with the wall damping heating and skin friction 10-30% above the local damping results. Furthermore, the local damping predictions have reasonable or good agreement with the experimental heating data for all cases. The impact of the two formulations on the van Driest damping function and the turbulent eddy viscosity distribution for a cold wall case indicate the importance of including temperature gradient effects. Grid requirements for accurate turbulent heating predictions are also studied. These results indicate that a cell Reynolds number of 1 is required for grid converged heating predictions, but coarser grids with a y(sup +) less than 2 are adequate for design of hypersonic vehicles. Based on the results of this study, it is recommended that the local damping formulation be used with the Baldwin-Lomax and Cebeci-Smith turbulence models in design and analysis of Hyper-X and future hypersonic vehicles.

A screening tool for delineating subregions of steady recharge within groundwater models

USGS Publications Warehouse

Dickinson, Jesse; Ferré, T.P.A.; Bakker, Mark; Crompton, Becky

2014-01-01

We have developed a screening method for simplifying groundwater models by delineating areas within the domain that can be represented using steady-state groundwater recharge. The screening method is based on an analytical solution for the damping of sinusoidal infiltration variations in homogeneous soils in the vadose zone. The damping depth is defined as the depth at which the flux variation damps to 5% of the variation at the land surface. Groundwater recharge may be considered steady where the damping depth is above the depth of the water table. The analytical solution approximates the vadose zone diffusivity as constant, and we evaluated when this approximation is reasonable. We evaluated the analytical solution through comparison of the damping depth computed by the analytic solution with the damping depth simulated by a numerical model that allows variable diffusivity. This comparison showed that the screening method conservatively identifies areas of steady recharge and is more accurate when water content and diffusivity are nearly constant. Nomograms of the damping factor (the ratio of the flux amplitude at any depth to the amplitude at the land surface) and the damping depth were constructed for clay and sand for periodic variations between 1 and 365 d and flux means and amplitudes from nearly 0 to 1 × 10−3 m d−1. We applied the screening tool to Central Valley, California, to identify areas of steady recharge. A MATLAB script was developed to compute the damping factor for any soil and any sinusoidal flux variation.

Numerical Experiments in Error Control for Sound Propagation Using a Damping Layer Boundary Treatment

NASA Technical Reports Server (NTRS)

Goodrich, John W.

2017-01-01

This paper presents results from numerical experiments for controlling the error caused by a damping layer boundary treatment when simulating the propagation of an acoustic signal from a continuous pressure source. The computations are with the 2D Linearized Euler Equations (LEE) for both a uniform mean flow and a steady parallel jet. The numerical experiments are with algorithms that are third, fifth, seventh and ninth order accurate in space and time. The numerical domain is enclosed in a damping layer boundary treatment. The damping is implemented in a time accurate manner, with simple polynomial damping profiles of second, fourth, sixth and eighth power. At the outer boundaries of the damping layer the propagating solution is uniformly set to zero. The complete boundary treatment is remarkably simple and intrinsically independant from the dimension of the spatial domain. The reported results show the relative effect on the error from the boundary treatment by varying the damping layer width, damping profile power, damping amplitude, propagtion time, grid resolution and algorithm order. The issue that is being addressed is not the accuracy of the numerical solution when compared to a mathematical solution, but the effect of the complete boundary treatment on the numerical solution, and to what degree the error in the numerical solution from the complete boundary treatment can be controlled. We report maximum relative absolute errors from just the boundary treatment that range from O[10-2] to O[10-7].

Dynamic response analysis of a 24-story damped steel structure

NASA Astrophysics Data System (ADS)

Feng, Demin; Miyama, Takafumi

2017-10-01

In Japanese and Chinese building codes, a two-stage design philosophy, damage limitation (small earthquake, Level 1) and life safety (extreme large earthquake, Level 2), is adopted. It is very interesting to compare the design method of a damped structure based on the two building codes. In the Chinese code, in order to be consistent with the conventional seismic design method, the damped structure is also designed at the small earthquake level. The effect of damper systems is considered by the additional damping ratio concept. The design force will be obtained from the damped design spectrum considering the reduction due to the additional damping ratio. The additional damping ratio by the damper system is usually calculated by a time history analysis method at the small earthquake level. The velocity dependent type dampers such as viscous dampers can function well even in the small earthquake level. But, if steel damper is used, which usually remains elastic in the small earthquake, there will be no additional damping ratio achieved. On the other hand, a time history analysis is used in Japan both for small earthquake and extreme large earthquake level. The characteristics of damper system and ductility of the structure can be modelled well. An existing 24-story steel frame is modified to demonstrate the design process of the damped structure based on the two building codes. Viscous wall type damper and low yield steel panel dampers are studied as the damper system.

Feasibility study of a large-scale tuned mass damper with eddy current damping mechanism

NASA Astrophysics Data System (ADS)

Wang, Zhihao; Chen, Zhengqing; Wang, Jianhui

2012-09-01

Tuned mass dampers (TMDs) have been widely used in recent years to mitigate structural vibration. However, the damping mechanisms employed in the TMDs are mostly based on viscous dampers, which have several well-known disadvantages, such as oil leakage and difficult adjustment of damping ratio for an operating TMD. Alternatively, eddy current damping (ECD) that does not require any contact with the main structure is a potential solution. This paper discusses the design, analysis, manufacture and testing of a large-scale horizontal TMD based on ECD. First, the theoretical model of ECD is formulated, then one large-scale horizontal TMD using ECD is constructed, and finally performance tests of the TMD are conducted. The test results show that the proposed TMD has a very low intrinsic damping ratio, while the damping ratio due to ECD is the dominant damping source, which can be as large as 15% in a proper configuration. In addition, the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results, and the source of this error is investigated. Moreover, it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates. In view of practical applications, possible improvements and feasibility considerations for the proposed TMD are then discussed. It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.

Damping effect on resonance bounds relationship of nanostructured ferromagnets and composites

NASA Astrophysics Data System (ADS)

Zhou, Peiheng; Liu, Tao; Xie, Jianliang; Deng, Longjiang

2012-06-01

In this paper, we introduce Gilbert damping parameter into the expression of resonance bounds relationship in nanomagnets to accomplish the depiction of damping effect, associated with an experimental study of ferromagnetic nanocrystalline flakes and their composites. Based on the intrinsic permeability retrieving and microwave spectrum fitting, a robust approach to the damping problem in the resonance study of high-frequency ferromagnets and composites is discussed.

RMS active damping augmentation

NASA Technical Reports Server (NTRS)

Gilbert, Michael G.; Scott, Michael A.; Demeo, Martha E.

1992-01-01

The topics are presented in viewgraph form and include: RMS active damping augmentation; potential space station assembly benefits to CSI; LaRC/JSC bridge program; control law design process; draper RMS simulator; MIMO acceleration control laws improve damping; potential load reduction benefit; DRS modified to model distributed accelerations; accelerometer location; Space Shuttle aft cockpit simulator; simulated shuttle video displays; SES test goals and objectives; and SES modifications to support RMS active damping augmentation.

Damping studies in Ni-Mn-Ga-Fe/PU polymer composites

NASA Astrophysics Data System (ADS)

Saranya, C.; Kumar, S. Vinodh; Seenithurai, S.; Pandyan, R. Kodi; Munieswaran, P.; Mahendran, M.

2015-06-01

Ni-Mn-Ga-Fe/PU polymer composite is prepared to investigate the damping behavior by using an indigenous experimental setup. The excellent damping properties of Ni-Mn-Ga-Fe alloys bonded with polymer matrix makes possible to develop new damping materials which are effective, less expensive and easier than bulk Ni-Mn-Ga. At low frequency, the stress amplitude increases and then smoothly decreases on increasing the frequency.